gcc/

[pf3gnuchains/gcc-fork.git] / gcc / config / mips / mips.c

/* Subroutines used for MIPS code generation.
   Copyright (C) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   Free Software Foundation, Inc.
   Contributed by A. Lichnewsky, lich@inria.inria.fr.
   Changes by Michael Meissner, meissner@osf.org.
   64-bit r4000 support by Ian Lance Taylor, ian@cygnus.com, and
   Brendan Eich, brendan@microunity.com.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include <signal.h>
#include "rtl.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "insn-attr.h"
#include "recog.h"
#include "toplev.h"
#include "output.h"
#include "tree.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
#include "flags.h"
#include "reload.h"
#include "tm_p.h"
#include "ggc.h"
#include "gstab.h"
#include "hashtab.h"
#include "debug.h"
#include "target.h"
#include "target-def.h"
#include "integrate.h"
#include "langhooks.h"
#include "cfglayout.h"
#include "sched-int.h"
#include "tree-gimple.h"
#include "bitmap.h"
#include "diagnostic.h"

/* True if X is an unspec wrapper around a SYMBOL_REF or LABEL_REF.  */
#define UNSPEC_ADDRESS_P(X)                                     \
  (GET_CODE (X) == UNSPEC                                       \
   && XINT (X, 1) >= UNSPEC_ADDRESS_FIRST                       \
   && XINT (X, 1) < UNSPEC_ADDRESS_FIRST + NUM_SYMBOL_TYPES)

/* Extract the symbol or label from UNSPEC wrapper X.  */
#define UNSPEC_ADDRESS(X) \
  XVECEXP (X, 0, 0)

/* Extract the symbol type from UNSPEC wrapper X.  */
#define UNSPEC_ADDRESS_TYPE(X) \
  ((enum mips_symbol_type) (XINT (X, 1) - UNSPEC_ADDRESS_FIRST))

/* The maximum distance between the top of the stack frame and the
   value $sp has when we save and restore registers.

   The value for normal-mode code must be a SMALL_OPERAND and must
   preserve the maximum stack alignment.  We therefore use a value
   of 0x7ff0 in this case.

   MIPS16e SAVE and RESTORE instructions can adjust the stack pointer by
   up to 0x7f8 bytes and can usually save or restore all the registers
   that we need to save or restore.  (Note that we can only use these
   instructions for o32, for which the stack alignment is 8 bytes.)

   We use a maximum gap of 0x100 or 0x400 for MIPS16 code when SAVE and
   RESTORE are not available.  We can then use unextended instructions
   to save and restore registers, and to allocate and deallocate the top
   part of the frame.  */
#define MIPS_MAX_FIRST_STACK_STEP                                       \
  (!TARGET_MIPS16 ? 0x7ff0                                              \
   : GENERATE_MIPS16E_SAVE_RESTORE ? 0x7f8                              \
   : TARGET_64BIT ? 0x100 : 0x400)

/* True if INSN is a mips.md pattern or asm statement.  */
#define USEFUL_INSN_P(INSN)                                             \
  (INSN_P (INSN)                                                        \
   && GET_CODE (PATTERN (INSN)) != USE                                  \
   && GET_CODE (PATTERN (INSN)) != CLOBBER                              \
   && GET_CODE (PATTERN (INSN)) != ADDR_VEC                             \
   && GET_CODE (PATTERN (INSN)) != ADDR_DIFF_VEC)

/* If INSN is a delayed branch sequence, return the first instruction
   in the sequence, otherwise return INSN itself.  */
#define SEQ_BEGIN(INSN)                                                 \
  (INSN_P (INSN) && GET_CODE (PATTERN (INSN)) == SEQUENCE               \
   ? XVECEXP (PATTERN (INSN), 0, 0)                                     \
   : (INSN))

/* Likewise for the last instruction in a delayed branch sequence.  */
#define SEQ_END(INSN)                                                   \
  (INSN_P (INSN) && GET_CODE (PATTERN (INSN)) == SEQUENCE               \
   ? XVECEXP (PATTERN (INSN), 0, XVECLEN (PATTERN (INSN), 0) - 1)       \
   : (INSN))

/* Execute the following loop body with SUBINSN set to each instruction
   between SEQ_BEGIN (INSN) and SEQ_END (INSN) inclusive.  */
#define FOR_EACH_SUBINSN(SUBINSN, INSN)                                 \
  for ((SUBINSN) = SEQ_BEGIN (INSN);                                    \
       (SUBINSN) != NEXT_INSN (SEQ_END (INSN));                         \
       (SUBINSN) = NEXT_INSN (SUBINSN))

/* True if bit BIT is set in VALUE.  */
#define BITSET_P(VALUE, BIT) (((VALUE) & (1 << (BIT))) != 0)

/* Classifies an address.

   ADDRESS_REG
       A natural register + offset address.  The register satisfies
       mips_valid_base_register_p and the offset is a const_arith_operand.

   ADDRESS_LO_SUM
       A LO_SUM rtx.  The first operand is a valid base register and
       the second operand is a symbolic address.

   ADDRESS_CONST_INT
       A signed 16-bit constant address.

   ADDRESS_SYMBOLIC:
       A constant symbolic address (equivalent to CONSTANT_SYMBOLIC).  */
enum mips_address_type {
  ADDRESS_REG,
  ADDRESS_LO_SUM,
  ADDRESS_CONST_INT,
  ADDRESS_SYMBOLIC
};

/* Macros to create an enumeration identifier for a function prototype.  */
#define MIPS_FTYPE_NAME1(A, B) MIPS_##A##_FTYPE_##B
#define MIPS_FTYPE_NAME2(A, B, C) MIPS_##A##_FTYPE_##B##_##C
#define MIPS_FTYPE_NAME3(A, B, C, D) MIPS_##A##_FTYPE_##B##_##C##_##D
#define MIPS_FTYPE_NAME4(A, B, C, D, E) MIPS_##A##_FTYPE_##B##_##C##_##D##_##E

/* Classifies the prototype of a builtin function.  */
enum mips_function_type
{
#define DEF_MIPS_FTYPE(NARGS, LIST) MIPS_FTYPE_NAME##NARGS LIST,
#include "config/mips/mips-ftypes.def"
#undef DEF_MIPS_FTYPE
  MIPS_MAX_FTYPE_MAX
};

/* Specifies how a builtin function should be converted into rtl.  */
enum mips_builtin_type
{
  /* The builtin corresponds directly to an .md pattern.  The return
     value is mapped to operand 0 and the arguments are mapped to
     operands 1 and above.  */
  MIPS_BUILTIN_DIRECT,

  /* The builtin corresponds directly to an .md pattern.  There is no return
     value and the arguments are mapped to operands 0 and above.  */
  MIPS_BUILTIN_DIRECT_NO_TARGET,

  /* The builtin corresponds to a comparison instruction followed by
     a mips_cond_move_tf_ps pattern.  The first two arguments are the
     values to compare and the second two arguments are the vector
     operands for the movt.ps or movf.ps instruction (in assembly order).  */
  MIPS_BUILTIN_MOVF,
  MIPS_BUILTIN_MOVT,

  /* The builtin corresponds to a V2SF comparison instruction.  Operand 0
     of this instruction is the result of the comparison, which has mode
     CCV2 or CCV4.  The function arguments are mapped to operands 1 and
     above.  The function's return value is an SImode boolean that is
     true under the following conditions:

     MIPS_BUILTIN_CMP_ANY: one of the registers is true
     MIPS_BUILTIN_CMP_ALL: all of the registers are true
     MIPS_BUILTIN_CMP_LOWER: the first register is true
     MIPS_BUILTIN_CMP_UPPER: the second register is true.  */
  MIPS_BUILTIN_CMP_ANY,
  MIPS_BUILTIN_CMP_ALL,
  MIPS_BUILTIN_CMP_UPPER,
  MIPS_BUILTIN_CMP_LOWER,

  /* As above, but the instruction only sets a single $fcc register.  */
  MIPS_BUILTIN_CMP_SINGLE,

  /* For generating bposge32 branch instructions in MIPS32 DSP ASE.  */
  MIPS_BUILTIN_BPOSGE32
};

/* Invokes MACRO (COND) for each c.cond.fmt condition.  */
#define MIPS_FP_CONDITIONS(MACRO) \
  MACRO (f),    \
  MACRO (un),   \
  MACRO (eq),   \
  MACRO (ueq),  \
  MACRO (olt),  \
  MACRO (ult),  \
  MACRO (ole),  \
  MACRO (ule),  \
  MACRO (sf),   \
  MACRO (ngle), \
  MACRO (seq),  \
  MACRO (ngl),  \
  MACRO (lt),   \
  MACRO (nge),  \
  MACRO (le),   \
  MACRO (ngt)

/* Enumerates the codes above as MIPS_FP_COND_<X>.  */
#define DECLARE_MIPS_COND(X) MIPS_FP_COND_ ## X
enum mips_fp_condition {
  MIPS_FP_CONDITIONS (DECLARE_MIPS_COND)
};

/* Index X provides the string representation of MIPS_FP_COND_<X>.  */
#define STRINGIFY(X) #X
static const char *const mips_fp_conditions[] = {
  MIPS_FP_CONDITIONS (STRINGIFY)
};

/* Information about a function's frame layout.  */
struct mips_frame_info GTY(())
{
  /* The size of the frame in bytes.  */
  HOST_WIDE_INT total_size;

  /* The number of bytes allocated to variables.  */
  HOST_WIDE_INT var_size;

  /* The number of bytes allocated to outgoing function arguments.  */
  HOST_WIDE_INT args_size;

  /* The number of bytes allocated to the .cprestore slot, or 0 if there
     is no such slot.  */
  HOST_WIDE_INT cprestore_size;

  /* Bit X is set if the function saves or restores GPR X.  */
  unsigned int mask;

  /* Likewise FPR X.  */
  unsigned int fmask;

  /* The number of GPRs and FPRs saved.  */
  unsigned int num_gp;
  unsigned int num_fp;

  /* The offset of the topmost GPR and FPR save slots from the top of
     the frame, or zero if no such slots are needed.  */
  HOST_WIDE_INT gp_save_offset;
  HOST_WIDE_INT fp_save_offset;

  /* Likewise, but giving offsets from the bottom of the frame.  */
  HOST_WIDE_INT gp_sp_offset;
  HOST_WIDE_INT fp_sp_offset;

  /* The offset of arg_pointer_rtx from frame_pointer_rtx.  */
  HOST_WIDE_INT arg_pointer_offset;

  /* The offset of hard_frame_pointer_rtx from frame_pointer_rtx.  */
  HOST_WIDE_INT hard_frame_pointer_offset;
};

struct machine_function GTY(()) {
  /* Pseudo-reg holding the value of $28 in a mips16 function which
     refers to GP relative global variables.  */
  rtx mips16_gp_pseudo_rtx;

  /* The number of extra stack bytes taken up by register varargs.
     This area is allocated by the callee at the very top of the frame.  */
  int varargs_size;

  /* Current frame information, calculated by mips_compute_frame_info.  */
  struct mips_frame_info frame;

  /* The register to use as the global pointer within this function.  */
  unsigned int global_pointer;

  /* True if mips_adjust_insn_length should ignore an instruction's
     hazard attribute.  */
  bool ignore_hazard_length_p;

  /* True if the whole function is suitable for .set noreorder and
     .set nomacro.  */
  bool all_noreorder_p;

  /* True if the function is known to have an instruction that needs $gp.  */
  bool has_gp_insn_p;

  /* True if we have emitted an instruction to initialize
     mips16_gp_pseudo_rtx.  */
  bool initialized_mips16_gp_pseudo_p;
};

/* Information about a single argument.  */
struct mips_arg_info
{
  /* True if the argument is passed in a floating-point register, or
     would have been if we hadn't run out of registers.  */
  bool fpr_p;

  /* The number of words passed in registers, rounded up.  */
  unsigned int reg_words;

  /* For EABI, the offset of the first register from GP_ARG_FIRST or
     FP_ARG_FIRST.  For other ABIs, the offset of the first register from
     the start of the ABI's argument structure (see the CUMULATIVE_ARGS
     comment for details).

     The value is MAX_ARGS_IN_REGISTERS if the argument is passed entirely
     on the stack.  */
  unsigned int reg_offset;

  /* The number of words that must be passed on the stack, rounded up.  */
  unsigned int stack_words;

  /* The offset from the start of the stack overflow area of the argument's
     first stack word.  Only meaningful when STACK_WORDS is nonzero.  */
  unsigned int stack_offset;
};


/* Information about an address described by mips_address_type.

   ADDRESS_CONST_INT
       No fields are used.

   ADDRESS_REG
       REG is the base register and OFFSET is the constant offset.

   ADDRESS_LO_SUM
       REG is the register that contains the high part of the address,
       OFFSET is the symbolic address being referenced and SYMBOL_TYPE
       is the type of OFFSET's symbol.

   ADDRESS_SYMBOLIC
       SYMBOL_TYPE is the type of symbol being referenced.  */

struct mips_address_info
{
  enum mips_address_type type;
  rtx reg;
  rtx offset;
  enum mips_symbol_type symbol_type;
};


/* One stage in a constant building sequence.  These sequences have
   the form:

        A = VALUE[0]
        A = A CODE[1] VALUE[1]
        A = A CODE[2] VALUE[2]
        ...

   where A is an accumulator, each CODE[i] is a binary rtl operation
   and each VALUE[i] is a constant integer.  */
struct mips_integer_op {
  enum rtx_code code;
  unsigned HOST_WIDE_INT value;
};


/* The largest number of operations needed to load an integer constant.
   The worst accepted case for 64-bit constants is LUI,ORI,SLL,ORI,SLL,ORI.
   When the lowest bit is clear, we can try, but reject a sequence with
   an extra SLL at the end.  */
#define MIPS_MAX_INTEGER_OPS 7

/* Information about a MIPS16e SAVE or RESTORE instruction.  */
struct mips16e_save_restore_info {
  /* The number of argument registers saved by a SAVE instruction.
     0 for RESTORE instructions.  */
  unsigned int nargs;

  /* Bit X is set if the instruction saves or restores GPR X.  */
  unsigned int mask;

  /* The total number of bytes to allocate.  */
  HOST_WIDE_INT size;
};

/* Global variables for machine-dependent things.  */

/* Threshold for data being put into the small data/bss area, instead
   of the normal data area.  */
int mips_section_threshold = -1;

/* Count the number of .file directives, so that .loc is up to date.  */
int num_source_filenames = 0;

/* Name of the file containing the current function.  */
const char *current_function_file = "";

/* Count the number of sdb related labels are generated (to find block
   start and end boundaries).  */
int sdb_label_count = 0;

/* Next label # for each statement for Silicon Graphics IRIS systems.  */
int sym_lineno = 0;

/* Map GCC register number to debugger register number.  */
int mips_dbx_regno[FIRST_PSEUDO_REGISTER];
int mips_dwarf_regno[FIRST_PSEUDO_REGISTER];

/* Number of nested .set noreorder, noat, nomacro, and volatile requests.  */
int set_noreorder;
int set_noat;
int set_nomacro;

/* The next branch instruction is a branch likely, not branch normal.  */
int mips_branch_likely;

/* The operands passed to the last cmpMM expander.  */
rtx cmp_operands[2];

/* The target cpu for code generation.  */
enum processor_type mips_arch;
const struct mips_cpu_info *mips_arch_info;

/* The target cpu for optimization and scheduling.  */
enum processor_type mips_tune;
const struct mips_cpu_info *mips_tune_info;

/* Which instruction set architecture to use.  */
int mips_isa;

/* The architecture selected by -mipsN.  */
static const struct mips_cpu_info *mips_isa_info;

/* Which ABI to use.  */
int mips_abi = MIPS_ABI_DEFAULT;

/* Cost information to use.  */
const struct mips_rtx_cost_data *mips_cost;

/* Remember the ambient target flags, excluding mips16.  */
static int mips_base_target_flags;
/* The mips16 command-line target flags only.  */
static bool mips_base_mips16;
/* Similar copies of option settings.  */
static int mips_flag_delayed_branch; /* flag_delayed_branch */
static int mips_base_schedule_insns; /* flag_schedule_insns */
static int mips_base_reorder_blocks_and_partition; /* flag_reorder... */
static int mips_base_move_loop_invariants; /* flag_move_loop_invariants */
static int mips_base_align_loops; /* align_loops */
static int mips_base_align_jumps; /* align_jumps */
static int mips_base_align_functions; /* align_functions */

/* The -mtext-loads setting.  */
enum mips_code_readable_setting mips_code_readable = CODE_READABLE_YES;

/* If TRUE, we split addresses into their high and low parts in the RTL.  */
int mips_split_addresses;

/* Mode used for saving/restoring general purpose registers.  */
static enum machine_mode gpr_mode;

/* Array giving truth value on whether or not a given hard register
   can support a given mode.  */
char mips_hard_regno_mode_ok[(int)MAX_MACHINE_MODE][FIRST_PSEUDO_REGISTER];

/* List of all MIPS punctuation characters used by print_operand.  */
char mips_print_operand_punct[256];

static GTY (()) int mips_output_filename_first_time = 1;

/* mips_split_p[X] is true if symbols of type X can be split by
   mips_split_symbol().  */
bool mips_split_p[NUM_SYMBOL_TYPES];

/* mips_lo_relocs[X] is the relocation to use when a symbol of type X
   appears in a LO_SUM.  It can be null if such LO_SUMs aren't valid or
   if they are matched by a special .md file pattern.  */
static const char *mips_lo_relocs[NUM_SYMBOL_TYPES];

/* Likewise for HIGHs.  */
static const char *mips_hi_relocs[NUM_SYMBOL_TYPES];

/* Map hard register number to register class */
const enum reg_class mips_regno_to_class[] =
{
  LEA_REGS,     LEA_REGS,       M16_NA_REGS,    V1_REG,
  M16_REGS,     M16_REGS,       M16_REGS,       M16_REGS,
  LEA_REGS,     LEA_REGS,       LEA_REGS,       LEA_REGS,
  LEA_REGS,     LEA_REGS,       LEA_REGS,       LEA_REGS,
  M16_NA_REGS,  M16_NA_REGS,    LEA_REGS,       LEA_REGS,
  LEA_REGS,     LEA_REGS,       LEA_REGS,       LEA_REGS,
  T_REG,        PIC_FN_ADDR_REG, LEA_REGS,      LEA_REGS,
  LEA_REGS,     LEA_REGS,       LEA_REGS,       LEA_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  FP_REGS,      FP_REGS,        FP_REGS,        FP_REGS,
  MD0_REG,      MD1_REG,        NO_REGS,        ST_REGS,
  ST_REGS,      ST_REGS,        ST_REGS,        ST_REGS,
  ST_REGS,      ST_REGS,        ST_REGS,        NO_REGS,
  NO_REGS,      ALL_REGS,       ALL_REGS,       NO_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP0_REGS,    COP0_REGS,      COP0_REGS,      COP0_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP2_REGS,    COP2_REGS,      COP2_REGS,      COP2_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  COP3_REGS,    COP3_REGS,      COP3_REGS,      COP3_REGS,
  DSP_ACC_REGS, DSP_ACC_REGS,   DSP_ACC_REGS,   DSP_ACC_REGS,
  DSP_ACC_REGS, DSP_ACC_REGS,   ALL_REGS,       ALL_REGS,
  ALL_REGS,     ALL_REGS,       ALL_REGS,       ALL_REGS
};

/* Table of machine dependent attributes.  */
const struct attribute_spec mips_attribute_table[] =
{
  { "long_call",   0, 0, false, true,  true,  NULL },
  { "far",         0, 0, false, true,  true,  NULL },
  { "near",        0, 0, false, true,  true,  NULL },
  /* Switch MIPS16 ASE on and off per-function.  We would really like
     to make these type attributes, but GCC doesn't provide the hooks
     we need to support the right conversion rules.  As declaration
     attributes, they affect code generation but don't carry other
     semantics.  */
  { "mips16",      0, 0, true,  false, false, NULL },
  { "nomips16",    0, 0, true,  false, false, NULL },
  { NULL,          0, 0, false, false, false, NULL }
};
\f
/* A table describing all the processors gcc knows about.  Names are
   matched in the order listed.  The first mention of an ISA level is
   taken as the canonical name for that ISA.

   To ease comparison, please keep this table in the same order
   as gas's mips_cpu_info_table[].  Please also make sure that
   MIPS_ISA_LEVEL_SPEC and MIPS_ARCH_FLOAT_SPEC handle all -march
   options correctly.  */
const struct mips_cpu_info mips_cpu_info_table[] = {
  /* Entries for generic ISAs */
  { "mips1", PROCESSOR_R3000, 1, 0 },
  { "mips2", PROCESSOR_R6000, 2, 0 },
  { "mips3", PROCESSOR_R4000, 3, 0 },
  { "mips4", PROCESSOR_R8000, 4, 0 },
  /* Prefer not to use branch-likely instructions for generic MIPS32rX
     and MIPS64rX code.  The instructions were officially deprecated
     in revisions 2 and earlier, but revision 3 is likely to downgrade
     that to a recommendation to avoid the instructions in code that
     isn't tuned to a specific processor.  */
  { "mips32", PROCESSOR_4KC, 32, PTF_AVOID_BRANCHLIKELY },
  { "mips32r2", PROCESSOR_M4K, 33, PTF_AVOID_BRANCHLIKELY },
  { "mips64", PROCESSOR_5KC, 64, PTF_AVOID_BRANCHLIKELY },

  /* MIPS I */
  { "r3000", PROCESSOR_R3000, 1, 0 },
  { "r2000", PROCESSOR_R3000, 1, 0 }, /* = r3000 */
  { "r3900", PROCESSOR_R3900, 1, 0 },

  /* MIPS II */
  { "r6000", PROCESSOR_R6000, 2, 0 },

  /* MIPS III */
  { "r4000", PROCESSOR_R4000, 3, 0 },
  { "vr4100", PROCESSOR_R4100, 3, 0 },
  { "vr4111", PROCESSOR_R4111, 3, 0 },
  { "vr4120", PROCESSOR_R4120, 3, 0 },
  { "vr4130", PROCESSOR_R4130, 3, 0 },
  { "vr4300", PROCESSOR_R4300, 3, 0 },
  { "r4400", PROCESSOR_R4000, 3, 0 }, /* = r4000 */
  { "r4600", PROCESSOR_R4600, 3, 0 },
  { "orion", PROCESSOR_R4600, 3, 0 }, /* = r4600 */
  { "r4650", PROCESSOR_R4650, 3, 0 },

  /* MIPS IV */
  { "r8000", PROCESSOR_R8000, 4, 0 },
  { "vr5000", PROCESSOR_R5000, 4, 0 },
  { "vr5400", PROCESSOR_R5400, 4, 0 },
  { "vr5500", PROCESSOR_R5500, 4, PTF_AVOID_BRANCHLIKELY },
  { "rm7000", PROCESSOR_R7000, 4, 0 },
  { "rm9000", PROCESSOR_R9000, 4, 0 },

  /* MIPS32 */
  { "4kc", PROCESSOR_4KC, 32, 0 },
  { "4km", PROCESSOR_4KC, 32, 0 }, /* = 4kc */
  { "4kp", PROCESSOR_4KP, 32, 0 },
  { "4ksc", PROCESSOR_4KC, 32, 0 },

  /* MIPS32 Release 2 */
  { "m4k", PROCESSOR_M4K, 33, 0 },
  { "4kec", PROCESSOR_4KC, 33, 0 },
  { "4kem", PROCESSOR_4KC, 33, 0 },
  { "4kep", PROCESSOR_4KP, 33, 0 },
  { "4ksd", PROCESSOR_4KC, 33, 0 },

  { "24kc", PROCESSOR_24KC, 33, 0 },
  { "24kf2_1", PROCESSOR_24KF2_1, 33, 0 },
  { "24kf", PROCESSOR_24KF2_1, 33, 0 },
  { "24kf1_1", PROCESSOR_24KF1_1, 33, 0 },
  { "24kfx", PROCESSOR_24KF1_1, 33, 0 },
  { "24kx", PROCESSOR_24KF1_1, 33, 0 },

  { "24kec", PROCESSOR_24KC, 33, 0 }, /* 24K with DSP */
  { "24kef2_1", PROCESSOR_24KF2_1, 33, 0 },
  { "24kef", PROCESSOR_24KF2_1, 33, 0 },
  { "24kef1_1", PROCESSOR_24KF1_1, 33, 0 },
  { "24kefx", PROCESSOR_24KF1_1, 33, 0 },
  { "24kex", PROCESSOR_24KF1_1, 33, 0 },

  { "34kc", PROCESSOR_24KC, 33, 0 }, /* 34K with MT/DSP */
  { "34kf2_1", PROCESSOR_24KF2_1, 33, 0 },
  { "34kf", PROCESSOR_24KF2_1, 33, 0 },
  { "34kf1_1", PROCESSOR_24KF1_1, 33, 0 },
  { "34kfx", PROCESSOR_24KF1_1, 33, 0 },
  { "34kx", PROCESSOR_24KF1_1, 33, 0 },

  { "74kc", PROCESSOR_74KC, 33, 0 }, /* 74K with DSPr2 */
  { "74kf2_1", PROCESSOR_74KF2_1, 33, 0 },
  { "74kf", PROCESSOR_74KF2_1, 33, 0 },
  { "74kf1_1", PROCESSOR_74KF1_1, 33, 0 },
  { "74kfx", PROCESSOR_74KF1_1, 33, 0 },
  { "74kx", PROCESSOR_74KF1_1, 33, 0 },
  { "74kf3_2", PROCESSOR_74KF3_2, 33, 0 },

  /* MIPS64 */
  { "5kc", PROCESSOR_5KC, 64, 0 },
  { "5kf", PROCESSOR_5KF, 64, 0 },
  { "20kc", PROCESSOR_20KC, 64, PTF_AVOID_BRANCHLIKELY },
  { "sb1", PROCESSOR_SB1, 64, PTF_AVOID_BRANCHLIKELY },
  { "sb1a", PROCESSOR_SB1A, 64, PTF_AVOID_BRANCHLIKELY },
  { "sr71000", PROCESSOR_SR71000, 64, PTF_AVOID_BRANCHLIKELY },
};

/* Default costs. If these are used for a processor we should look
   up the actual costs.  */
#define DEFAULT_COSTS COSTS_N_INSNS (6),  /* fp_add */       \
                      COSTS_N_INSNS (7),  /* fp_mult_sf */   \
                      COSTS_N_INSNS (8),  /* fp_mult_df */   \
                      COSTS_N_INSNS (23), /* fp_div_sf */    \
                      COSTS_N_INSNS (36), /* fp_div_df */    \
                      COSTS_N_INSNS (10), /* int_mult_si */  \
                      COSTS_N_INSNS (10), /* int_mult_di */  \
                      COSTS_N_INSNS (69), /* int_div_si */   \
                      COSTS_N_INSNS (69), /* int_div_di */   \
                                       2, /* branch_cost */  \
                                       4  /* memory_latency */

/* Need to replace these with the costs of calling the appropriate
   libgcc routine.  */
#define SOFT_FP_COSTS COSTS_N_INSNS (256), /* fp_add */       \
                      COSTS_N_INSNS (256), /* fp_mult_sf */   \
                      COSTS_N_INSNS (256), /* fp_mult_df */   \
                      COSTS_N_INSNS (256), /* fp_div_sf */    \
                      COSTS_N_INSNS (256)  /* fp_div_df */

static struct mips_rtx_cost_data const mips_rtx_cost_optimize_size =
  {
      COSTS_N_INSNS (1),            /* fp_add */
      COSTS_N_INSNS (1),            /* fp_mult_sf */
      COSTS_N_INSNS (1),            /* fp_mult_df */
      COSTS_N_INSNS (1),            /* fp_div_sf */
      COSTS_N_INSNS (1),            /* fp_div_df */
      COSTS_N_INSNS (1),            /* int_mult_si */
      COSTS_N_INSNS (1),            /* int_mult_di */
      COSTS_N_INSNS (1),            /* int_div_si */
      COSTS_N_INSNS (1),            /* int_div_di */
                       2,           /* branch_cost */
                       4            /* memory_latency */
  };

static struct mips_rtx_cost_data const mips_rtx_cost_data[PROCESSOR_MAX] =
  {
    { /* R3000 */
      COSTS_N_INSNS (2),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (12),           /* fp_div_sf */
      COSTS_N_INSNS (19),           /* fp_div_df */
      COSTS_N_INSNS (12),           /* int_mult_si */
      COSTS_N_INSNS (12),           /* int_mult_di */
      COSTS_N_INSNS (35),           /* int_div_si */
      COSTS_N_INSNS (35),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */

    },
    { /* 4KC */
      SOFT_FP_COSTS,
      COSTS_N_INSNS (6),            /* int_mult_si */
      COSTS_N_INSNS (6),            /* int_mult_di */
      COSTS_N_INSNS (36),           /* int_div_si */
      COSTS_N_INSNS (36),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 4KP */
      SOFT_FP_COSTS,
      COSTS_N_INSNS (36),           /* int_mult_si */
      COSTS_N_INSNS (36),           /* int_mult_di */
      COSTS_N_INSNS (37),           /* int_div_si */
      COSTS_N_INSNS (37),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 5KC */
      SOFT_FP_COSTS,
      COSTS_N_INSNS (4),            /* int_mult_si */
      COSTS_N_INSNS (11),           /* int_mult_di */
      COSTS_N_INSNS (36),           /* int_div_si */
      COSTS_N_INSNS (68),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 5KF */
      COSTS_N_INSNS (4),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (17),           /* fp_div_sf */
      COSTS_N_INSNS (32),           /* fp_div_df */
      COSTS_N_INSNS (4),            /* int_mult_si */
      COSTS_N_INSNS (11),           /* int_mult_di */
      COSTS_N_INSNS (36),           /* int_div_si */
      COSTS_N_INSNS (68),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 20KC */
      COSTS_N_INSNS (4),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (17),           /* fp_div_sf */
      COSTS_N_INSNS (32),           /* fp_div_df */
      COSTS_N_INSNS (4),            /* int_mult_si */
      COSTS_N_INSNS (7),            /* int_mult_di */
      COSTS_N_INSNS (42),           /* int_div_si */
      COSTS_N_INSNS (72),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 24KC */
      SOFT_FP_COSTS,
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 24KF2_1 */
      COSTS_N_INSNS (8),            /* fp_add */
      COSTS_N_INSNS (8),            /* fp_mult_sf */
      COSTS_N_INSNS (10),           /* fp_mult_df */
      COSTS_N_INSNS (34),           /* fp_div_sf */
      COSTS_N_INSNS (64),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 24KF1_1 */
      COSTS_N_INSNS (4),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (17),           /* fp_div_sf */
      COSTS_N_INSNS (32),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 74KC */
      SOFT_FP_COSTS,
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 74KF2_1 */
      COSTS_N_INSNS (8),            /* fp_add */
      COSTS_N_INSNS (8),            /* fp_mult_sf */
      COSTS_N_INSNS (10),           /* fp_mult_df */
      COSTS_N_INSNS (34),           /* fp_div_sf */
      COSTS_N_INSNS (64),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 74KF1_1 */
      COSTS_N_INSNS (4),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (17),           /* fp_div_sf */
      COSTS_N_INSNS (32),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* 74KF3_2 */
      COSTS_N_INSNS (6),            /* fp_add */
      COSTS_N_INSNS (6),            /* fp_mult_sf */
      COSTS_N_INSNS (7),            /* fp_mult_df */
      COSTS_N_INSNS (25),           /* fp_div_sf */
      COSTS_N_INSNS (48),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (41),           /* int_div_si */
      COSTS_N_INSNS (41),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* M4k */
      DEFAULT_COSTS
    },
    { /* R3900 */
      COSTS_N_INSNS (2),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (12),           /* fp_div_sf */
      COSTS_N_INSNS (19),           /* fp_div_df */
      COSTS_N_INSNS (2),            /* int_mult_si */
      COSTS_N_INSNS (2),            /* int_mult_di */
      COSTS_N_INSNS (35),           /* int_div_si */
      COSTS_N_INSNS (35),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* R6000 */
      COSTS_N_INSNS (3),            /* fp_add */
      COSTS_N_INSNS (5),            /* fp_mult_sf */
      COSTS_N_INSNS (6),            /* fp_mult_df */
      COSTS_N_INSNS (15),           /* fp_div_sf */
      COSTS_N_INSNS (16),           /* fp_div_df */
      COSTS_N_INSNS (17),           /* int_mult_si */
      COSTS_N_INSNS (17),           /* int_mult_di */
      COSTS_N_INSNS (38),           /* int_div_si */
      COSTS_N_INSNS (38),           /* int_div_di */
                       2,           /* branch_cost */
                       6            /* memory_latency */
    },
    { /* R4000 */
       COSTS_N_INSNS (6),           /* fp_add */
       COSTS_N_INSNS (7),           /* fp_mult_sf */
       COSTS_N_INSNS (8),           /* fp_mult_df */
       COSTS_N_INSNS (23),          /* fp_div_sf */
       COSTS_N_INSNS (36),          /* fp_div_df */
       COSTS_N_INSNS (10),          /* int_mult_si */
       COSTS_N_INSNS (10),          /* int_mult_di */
       COSTS_N_INSNS (69),          /* int_div_si */
       COSTS_N_INSNS (69),          /* int_div_di */
                        2,          /* branch_cost */
                        6           /* memory_latency */
    },
    { /* R4100 */
      DEFAULT_COSTS
    },
    { /* R4111 */
      DEFAULT_COSTS
    },
    { /* R4120 */
      DEFAULT_COSTS
    },
    { /* R4130 */
      /* The only costs that appear to be updated here are
         integer multiplication.  */
      SOFT_FP_COSTS,
      COSTS_N_INSNS (4),            /* int_mult_si */
      COSTS_N_INSNS (6),            /* int_mult_di */
      COSTS_N_INSNS (69),           /* int_div_si */
      COSTS_N_INSNS (69),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* R4300 */
      DEFAULT_COSTS
    },
    { /* R4600 */
      DEFAULT_COSTS
    },
    { /* R4650 */
      DEFAULT_COSTS
    },
    { /* R5000 */
      COSTS_N_INSNS (6),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (5),            /* fp_mult_df */
      COSTS_N_INSNS (23),           /* fp_div_sf */
      COSTS_N_INSNS (36),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (5),            /* int_mult_di */
      COSTS_N_INSNS (36),           /* int_div_si */
      COSTS_N_INSNS (36),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* R5400 */
      COSTS_N_INSNS (6),            /* fp_add */
      COSTS_N_INSNS (5),            /* fp_mult_sf */
      COSTS_N_INSNS (6),            /* fp_mult_df */
      COSTS_N_INSNS (30),           /* fp_div_sf */
      COSTS_N_INSNS (59),           /* fp_div_df */
      COSTS_N_INSNS (3),            /* int_mult_si */
      COSTS_N_INSNS (4),            /* int_mult_di */
      COSTS_N_INSNS (42),           /* int_div_si */
      COSTS_N_INSNS (74),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* R5500 */
      COSTS_N_INSNS (6),            /* fp_add */
      COSTS_N_INSNS (5),            /* fp_mult_sf */
      COSTS_N_INSNS (6),            /* fp_mult_df */
      COSTS_N_INSNS (30),           /* fp_div_sf */
      COSTS_N_INSNS (59),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (9),            /* int_mult_di */
      COSTS_N_INSNS (42),           /* int_div_si */
      COSTS_N_INSNS (74),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* R7000 */
      /* The only costs that are changed here are
         integer multiplication.  */
      COSTS_N_INSNS (6),            /* fp_add */
      COSTS_N_INSNS (7),            /* fp_mult_sf */
      COSTS_N_INSNS (8),            /* fp_mult_df */
      COSTS_N_INSNS (23),           /* fp_div_sf */
      COSTS_N_INSNS (36),           /* fp_div_df */
      COSTS_N_INSNS (5),            /* int_mult_si */
      COSTS_N_INSNS (9),            /* int_mult_di */
      COSTS_N_INSNS (69),           /* int_div_si */
      COSTS_N_INSNS (69),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* R8000 */
      DEFAULT_COSTS
    },
    { /* R9000 */
      /* The only costs that are changed here are
         integer multiplication.  */
      COSTS_N_INSNS (6),            /* fp_add */
      COSTS_N_INSNS (7),            /* fp_mult_sf */
      COSTS_N_INSNS (8),            /* fp_mult_df */
      COSTS_N_INSNS (23),           /* fp_div_sf */
      COSTS_N_INSNS (36),           /* fp_div_df */
      COSTS_N_INSNS (3),            /* int_mult_si */
      COSTS_N_INSNS (8),            /* int_mult_di */
      COSTS_N_INSNS (69),           /* int_div_si */
      COSTS_N_INSNS (69),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* SB1 */
      /* These costs are the same as the SB-1A below.  */
      COSTS_N_INSNS (4),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (4),            /* fp_mult_df */
      COSTS_N_INSNS (24),           /* fp_div_sf */
      COSTS_N_INSNS (32),           /* fp_div_df */
      COSTS_N_INSNS (3),            /* int_mult_si */
      COSTS_N_INSNS (4),            /* int_mult_di */
      COSTS_N_INSNS (36),           /* int_div_si */
      COSTS_N_INSNS (68),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* SB1-A */
      /* These costs are the same as the SB-1 above.  */
      COSTS_N_INSNS (4),            /* fp_add */
      COSTS_N_INSNS (4),            /* fp_mult_sf */
      COSTS_N_INSNS (4),            /* fp_mult_df */
      COSTS_N_INSNS (24),           /* fp_div_sf */
      COSTS_N_INSNS (32),           /* fp_div_df */
      COSTS_N_INSNS (3),            /* int_mult_si */
      COSTS_N_INSNS (4),            /* int_mult_di */
      COSTS_N_INSNS (36),           /* int_div_si */
      COSTS_N_INSNS (68),           /* int_div_di */
                       1,           /* branch_cost */
                       4            /* memory_latency */
    },
    { /* SR71000 */
      DEFAULT_COSTS
    },
  };
\f
/* Use a hash table to keep track of implicit mips16/nomips16 attributes
   for -mflip_mips16.  It maps decl names onto a boolean mode setting.  */

struct mflip_mips16_entry GTY (()) {
  const char *name;
  bool mips16_p;
};
static GTY ((param_is (struct mflip_mips16_entry))) htab_t mflip_mips16_htab;

/* Hash table callbacks for mflip_mips16_htab.  */

static hashval_t
mflip_mips16_htab_hash (const void *entry)
{
  return htab_hash_string (((const struct mflip_mips16_entry *) entry)->name);
}

static int
mflip_mips16_htab_eq (const void *entry, const void *name)
{
  return strcmp (((const struct mflip_mips16_entry *) entry)->name,
                 (const char *) name) == 0;
}

static GTY(()) int mips16_flipper;

/* DECL is a function that needs a default "mips16" or "nomips16" attribute
   for -mflip-mips16.  Return true if it should use "mips16" and false if
   it should use "nomips16".  */

static bool
mflip_mips16_use_mips16_p (tree decl)
{
  struct mflip_mips16_entry *entry;
  const char *name;
  hashval_t hash;
  void **slot;

  /* Use the opposite of the command-line setting for anonymous decls.  */
  if (!DECL_NAME (decl))
    return !mips_base_mips16;

  if (!mflip_mips16_htab)
    mflip_mips16_htab = htab_create_ggc (37, mflip_mips16_htab_hash,
                                         mflip_mips16_htab_eq, NULL);

  name = IDENTIFIER_POINTER (DECL_NAME (decl));
  hash = htab_hash_string (name);
  slot = htab_find_slot_with_hash (mflip_mips16_htab, name, hash, INSERT);
  entry = (struct mflip_mips16_entry *) *slot;
  if (!entry)
    {
      mips16_flipper = !mips16_flipper;
      entry = GGC_NEW (struct mflip_mips16_entry);
      entry->name = name;
      entry->mips16_p = mips16_flipper ? !mips_base_mips16 : mips_base_mips16;
      *slot = entry;
    }
  return entry->mips16_p;
}
\f
/* Predicates to test for presence of "near" and "far"/"long_call"
   attributes on the given TYPE.  */

static bool
mips_near_type_p (const_tree type)
{
  return lookup_attribute ("near", TYPE_ATTRIBUTES (type)) != NULL;
}

static bool
mips_far_type_p (const_tree type)
{
  return (lookup_attribute ("long_call", TYPE_ATTRIBUTES (type)) != NULL
          || lookup_attribute ("far", TYPE_ATTRIBUTES (type)) != NULL);
}

/* Similar predicates for "mips16"/"nomips16" attributes.  */

static bool
mips_mips16_decl_p (const_tree decl)
{
  return lookup_attribute ("mips16", DECL_ATTRIBUTES (decl)) != NULL;
}

static bool
mips_nomips16_decl_p (const_tree decl)
{
  return lookup_attribute ("nomips16", DECL_ATTRIBUTES (decl)) != NULL;
}

/* Return true if function DECL is a MIPS16 function.  Return the ambient
   setting if DECL is null.  */

static bool
mips_use_mips16_mode_p (tree decl)
{
  if (decl)
    {
      /* Nested functions must use the same frame pointer as their
         parent and must therefore use the same ISA mode.  */
      tree parent = decl_function_context (decl);
      if (parent)
        decl = parent;
      if (mips_mips16_decl_p (decl))
        return true;
      if (mips_nomips16_decl_p (decl))
        return false;
    }
  return mips_base_mips16;
}

/* Return 0 if the attributes for two types are incompatible, 1 if they
   are compatible, and 2 if they are nearly compatible (which causes a
   warning to be generated).  */

static int
mips_comp_type_attributes (const_tree type1, const_tree type2)
{
  /* Check for mismatch of non-default calling convention.  */
  if (TREE_CODE (type1) != FUNCTION_TYPE)
    return 1;

  /* Disallow mixed near/far attributes.  */
  if (mips_far_type_p (type1) && mips_near_type_p (type2))
    return 0;
  if (mips_near_type_p (type1) && mips_far_type_p (type2))
    return 0;

  return 1;
}

/* Implement TARGET_INSERT_ATTRIBUTES.  */

static void
mips_insert_attributes (tree decl, tree *attributes)
{
  const char *name;
  bool mips16_p, nomips16_p;

  /* Check for "mips16" and "nomips16" attributes.  */
  mips16_p = lookup_attribute ("mips16", *attributes) != NULL;
  nomips16_p = lookup_attribute ("nomips16", *attributes) != NULL;
  if (TREE_CODE (decl) != FUNCTION_DECL)
    {
      if (mips16_p)
        error ("%qs attribute only applies to functions", "mips16");
      if (nomips16_p)
        error ("%qs attribute only applies to functions", "nomips16");
    }
  else
    {
      mips16_p |= mips_mips16_decl_p (decl);
      nomips16_p |= mips_nomips16_decl_p (decl);
      if (mips16_p || nomips16_p)
        {
          /* DECL cannot be simultaneously mips16 and nomips16.  */
          if (mips16_p && nomips16_p)
            error ("%qs cannot have both %<mips16%> and "
                   "%<nomips16%> attributes",
                   IDENTIFIER_POINTER (DECL_NAME (decl)));
        }
      else if (TARGET_FLIP_MIPS16 && !DECL_ARTIFICIAL (decl))
        {
          /* Implement -mflip-mips16.  If DECL has neither a "nomips16" nor a
             "mips16" attribute, arbitrarily pick one.  We must pick the same
             setting for duplicate declarations of a function.  */
          name = mflip_mips16_use_mips16_p (decl) ? "mips16" : "nomips16";
          *attributes = tree_cons (get_identifier (name), NULL, *attributes);
        }
    }
}

/* Implement TARGET_MERGE_DECL_ATTRIBUTES.  */

static tree
mips_merge_decl_attributes (tree olddecl, tree newdecl)
{
  /* The decls' "mips16" and "nomips16" attributes must match exactly.  */
  if (mips_mips16_decl_p (olddecl) != mips_mips16_decl_p (newdecl))
    error ("%qs redeclared with conflicting %qs attributes",
           IDENTIFIER_POINTER (DECL_NAME (newdecl)), "mips16");
  if (mips_nomips16_decl_p (olddecl) != mips_nomips16_decl_p (newdecl))
    error ("%qs redeclared with conflicting %qs attributes",
           IDENTIFIER_POINTER (DECL_NAME (newdecl)), "nomips16");

  return merge_attributes (DECL_ATTRIBUTES (olddecl),
                           DECL_ATTRIBUTES (newdecl));
}
\f
/* If X is a PLUS of a CONST_INT, return the two terms in *BASE_PTR
   and *OFFSET_PTR.  Return X in *BASE_PTR and 0 in *OFFSET_PTR otherwise.  */

static void
mips_split_plus (rtx x, rtx *base_ptr, HOST_WIDE_INT *offset_ptr)
{
  if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
    {
      *base_ptr = XEXP (x, 0);
      *offset_ptr = INTVAL (XEXP (x, 1));
    }
  else
    {
      *base_ptr = x;
      *offset_ptr = 0;
    }
}
\f
static unsigned int mips_build_integer (struct mips_integer_op *,
                                        unsigned HOST_WIDE_INT);

/* Subroutine of mips_build_integer (with the same interface).
   Assume that the final action in the sequence should be a left shift.  */

static unsigned int
mips_build_shift (struct mips_integer_op *codes, HOST_WIDE_INT value)
{
  unsigned int i, shift;

  /* Shift VALUE right until its lowest bit is set.  Shift arithmetically
     since signed numbers are easier to load than unsigned ones.  */
  shift = 0;
  while ((value & 1) == 0)
    value /= 2, shift++;

  i = mips_build_integer (codes, value);
  codes[i].code = ASHIFT;
  codes[i].value = shift;
  return i + 1;
}


/* As for mips_build_shift, but assume that the final action will be
   an IOR or PLUS operation.  */

static unsigned int
mips_build_lower (struct mips_integer_op *codes, unsigned HOST_WIDE_INT value)
{
  unsigned HOST_WIDE_INT high;
  unsigned int i;

  high = value & ~(unsigned HOST_WIDE_INT) 0xffff;
  if (!LUI_OPERAND (high) && (value & 0x18000) == 0x18000)
    {
      /* The constant is too complex to load with a simple lui/ori pair
         so our goal is to clear as many trailing zeros as possible.
         In this case, we know bit 16 is set and that the low 16 bits
         form a negative number.  If we subtract that number from VALUE,
         we will clear at least the lowest 17 bits, maybe more.  */
      i = mips_build_integer (codes, CONST_HIGH_PART (value));
      codes[i].code = PLUS;
      codes[i].value = CONST_LOW_PART (value);
    }
  else
    {
      i = mips_build_integer (codes, high);
      codes[i].code = IOR;
      codes[i].value = value & 0xffff;
    }
  return i + 1;
}


/* Fill CODES with a sequence of rtl operations to load VALUE.
   Return the number of operations needed.  */

static unsigned int
mips_build_integer (struct mips_integer_op *codes,
                    unsigned HOST_WIDE_INT value)
{
  if (SMALL_OPERAND (value)
      || SMALL_OPERAND_UNSIGNED (value)
      || LUI_OPERAND (value))
    {
      /* The value can be loaded with a single instruction.  */
      codes[0].code = UNKNOWN;
      codes[0].value = value;
      return 1;
    }
  else if ((value & 1) != 0 || LUI_OPERAND (CONST_HIGH_PART (value)))
    {
      /* Either the constant is a simple LUI/ORI combination or its
         lowest bit is set.  We don't want to shift in this case.  */
      return mips_build_lower (codes, value);
    }
  else if ((value & 0xffff) == 0)
    {
      /* The constant will need at least three actions.  The lowest
         16 bits are clear, so the final action will be a shift.  */
      return mips_build_shift (codes, value);
    }
  else
    {
      /* The final action could be a shift, add or inclusive OR.
         Rather than use a complex condition to select the best
         approach, try both mips_build_shift and mips_build_lower
         and pick the one that gives the shortest sequence.
         Note that this case is only used once per constant.  */
      struct mips_integer_op alt_codes[MIPS_MAX_INTEGER_OPS];
      unsigned int cost, alt_cost;

      cost = mips_build_shift (codes, value);
      alt_cost = mips_build_lower (alt_codes, value);
      if (alt_cost < cost)
        {
          memcpy (codes, alt_codes, alt_cost * sizeof (codes[0]));
          cost = alt_cost;
        }
      return cost;
    }
}
\f
/* Return true if X is a thread-local symbol.  */

static bool
mips_tls_operand_p (rtx x)
{
  return GET_CODE (x) == SYMBOL_REF && SYMBOL_REF_TLS_MODEL (x) != 0;
}

/* Return true if SYMBOL_REF X is associated with a global symbol
   (in the STB_GLOBAL sense).  */

static bool
mips_global_symbol_p (const_rtx x)
{
  const_tree const decl = SYMBOL_REF_DECL (x);

  if (!decl)
    return !SYMBOL_REF_LOCAL_P (x);

  /* Weakref symbols are not TREE_PUBLIC, but their targets are global
     or weak symbols.  Relocations in the object file will be against
     the target symbol, so it's that symbol's binding that matters here.  */
  return DECL_P (decl) && (TREE_PUBLIC (decl) || DECL_WEAK (decl));
}

/* Return true if SYMBOL_REF X binds locally.  */

static bool
mips_symbol_binds_local_p (const_rtx x)
{
  return (SYMBOL_REF_DECL (x)
          ? targetm.binds_local_p (SYMBOL_REF_DECL (x))
          : SYMBOL_REF_LOCAL_P (x));
}

/* Return true if rtx constants of mode MODE should be put into a small
   data section.  */

static bool
mips_rtx_constant_in_small_data_p (enum machine_mode mode)
{
  return (!TARGET_EMBEDDED_DATA
          && TARGET_LOCAL_SDATA
          && GET_MODE_SIZE (mode) <= mips_section_threshold);
}

/* Return true if X should not be moved directly into register $25.
   We need this because many versions of GAS will treat "la $25,foo" as
   part of a call sequence and so allow a global "foo" to be lazily bound.  */

bool
mips_dangerous_for_la25_p (rtx x)
{
  return (!TARGET_EXPLICIT_RELOCS
          && TARGET_USE_GOT
          && GET_CODE (x) == SYMBOL_REF
          && mips_global_symbol_p (x));
}

/* Return the method that should be used to access SYMBOL_REF or
   LABEL_REF X in context CONTEXT.  */

static enum mips_symbol_type
mips_classify_symbol (const_rtx x, enum mips_symbol_context context)
{
  if (TARGET_RTP_PIC)
    return SYMBOL_GOT_DISP;

  if (GET_CODE (x) == LABEL_REF)
    {
      /* LABEL_REFs are used for jump tables as well as text labels.
         Only return SYMBOL_PC_RELATIVE if we know the label is in
         the text section.  */
      if (TARGET_MIPS16_SHORT_JUMP_TABLES)
        return SYMBOL_PC_RELATIVE;
      if (TARGET_ABICALLS && !TARGET_ABSOLUTE_ABICALLS)
        return SYMBOL_GOT_PAGE_OFST;
      return SYMBOL_ABSOLUTE;
    }

  gcc_assert (GET_CODE (x) == SYMBOL_REF);

  if (SYMBOL_REF_TLS_MODEL (x))
    return SYMBOL_TLS;

  if (CONSTANT_POOL_ADDRESS_P (x))
    {
      if (TARGET_MIPS16_TEXT_LOADS)
        return SYMBOL_PC_RELATIVE;

      if (TARGET_MIPS16_PCREL_LOADS && context == SYMBOL_CONTEXT_MEM)
        return SYMBOL_PC_RELATIVE;

      if (mips_rtx_constant_in_small_data_p (get_pool_mode (x)))
        return SYMBOL_GP_RELATIVE;
    }

  /* Do not use small-data accesses for weak symbols; they may end up
     being zero.  */
  if (TARGET_GPOPT
      && SYMBOL_REF_SMALL_P (x)
      && !SYMBOL_REF_WEAK (x))
    return SYMBOL_GP_RELATIVE;

  /* Don't use GOT accesses for locally-binding symbols when -mno-shared
     is in effect.  */
  if (TARGET_ABICALLS
      && !(TARGET_ABSOLUTE_ABICALLS && mips_symbol_binds_local_p (x)))
    {
      /* There are three cases to consider:

            - o32 PIC (either with or without explicit relocs)
            - n32/n64 PIC without explicit relocs
            - n32/n64 PIC with explicit relocs

         In the first case, both local and global accesses will use an
         R_MIPS_GOT16 relocation.  We must correctly predict which of
         the two semantics (local or global) the assembler and linker
         will apply.  The choice depends on the symbol's binding rather
         than its visibility.

         In the second case, the assembler will not use R_MIPS_GOT16
         relocations, but it chooses between local and global accesses
         in the same way as for o32 PIC.

         In the third case we have more freedom since both forms of
         access will work for any kind of symbol.  However, there seems
         little point in doing things differently.  */
      if (mips_global_symbol_p (x))
        return SYMBOL_GOT_DISP;

      return SYMBOL_GOT_PAGE_OFST;
    }

  if (TARGET_MIPS16_PCREL_LOADS && context != SYMBOL_CONTEXT_CALL)
    return SYMBOL_FORCE_TO_MEM;
  return SYMBOL_ABSOLUTE;
}

/* Classify symbolic expression X, given that it appears in context
   CONTEXT.  */

static enum mips_symbol_type
mips_classify_symbolic_expression (rtx x, enum mips_symbol_context context)
{
  rtx offset;

  split_const (x, &x, &offset);
  if (UNSPEC_ADDRESS_P (x))
    return UNSPEC_ADDRESS_TYPE (x);

  return mips_classify_symbol (x, context);
}

/* Return true if OFFSET is within the range [0, ALIGN), where ALIGN
   is the alignment (in bytes) of SYMBOL_REF X.  */

static bool
mips_offset_within_alignment_p (rtx x, HOST_WIDE_INT offset)
{
  /* If for some reason we can't get the alignment for the
     symbol, initializing this to one means we will only accept
     a zero offset.  */
  HOST_WIDE_INT align = 1;
  tree t;

  /* Get the alignment of the symbol we're referring to.  */
  t = SYMBOL_REF_DECL (x);
  if (t)
    align = DECL_ALIGN_UNIT (t);

  return offset >= 0 && offset < align;
}

/* Return true if X is a symbolic constant that can be used in context
   CONTEXT.  If it is, store the type of the symbol in *SYMBOL_TYPE.  */

bool
mips_symbolic_constant_p (rtx x, enum mips_symbol_context context,
                          enum mips_symbol_type *symbol_type)
{
  rtx offset;

  split_const (x, &x, &offset);
  if (UNSPEC_ADDRESS_P (x))
    {
      *symbol_type = UNSPEC_ADDRESS_TYPE (x);
      x = UNSPEC_ADDRESS (x);
    }
  else if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
    {
      *symbol_type = mips_classify_symbol (x, context);
      if (*symbol_type == SYMBOL_TLS)
        return false;
    }
  else
    return false;

  if (offset == const0_rtx)
    return true;

  /* Check whether a nonzero offset is valid for the underlying
     relocations.  */
  switch (*symbol_type)
    {
    case SYMBOL_ABSOLUTE:
    case SYMBOL_FORCE_TO_MEM:
    case SYMBOL_32_HIGH:
    case SYMBOL_64_HIGH:
    case SYMBOL_64_MID:
    case SYMBOL_64_LOW:
      /* If the target has 64-bit pointers and the object file only
         supports 32-bit symbols, the values of those symbols will be
         sign-extended.  In this case we can't allow an arbitrary offset
         in case the 32-bit value X + OFFSET has a different sign from X.  */
      if (Pmode == DImode && !ABI_HAS_64BIT_SYMBOLS)
        return offset_within_block_p (x, INTVAL (offset));

      /* In other cases the relocations can handle any offset.  */
      return true;

    case SYMBOL_PC_RELATIVE:
      /* Allow constant pool references to be converted to LABEL+CONSTANT.
         In this case, we no longer have access to the underlying constant,
         but the original symbol-based access was known to be valid.  */
      if (GET_CODE (x) == LABEL_REF)
        return true;

      /* Fall through.  */

    case SYMBOL_GP_RELATIVE:
      /* Make sure that the offset refers to something within the
         same object block.  This should guarantee that the final
         PC- or GP-relative offset is within the 16-bit limit.  */
      return offset_within_block_p (x, INTVAL (offset));

    case SYMBOL_GOT_PAGE_OFST:
    case SYMBOL_GOTOFF_PAGE:
      /* If the symbol is global, the GOT entry will contain the symbol's
         address, and we will apply a 16-bit offset after loading it.
         If the symbol is local, the linker should provide enough local
         GOT entries for a 16-bit offset, but larger offsets may lead
         to GOT overflow.  */
      return SMALL_INT (offset);

    case SYMBOL_TPREL:
    case SYMBOL_DTPREL:
      /* There is no carry between the HI and LO REL relocations, so the
         offset is only valid if we know it won't lead to such a carry.  */
      return mips_offset_within_alignment_p (x, INTVAL (offset));

    case SYMBOL_GOT_DISP:
    case SYMBOL_GOTOFF_DISP:
    case SYMBOL_GOTOFF_CALL:
    case SYMBOL_GOTOFF_LOADGP:
    case SYMBOL_TLSGD:
    case SYMBOL_TLSLDM:
    case SYMBOL_GOTTPREL:
    case SYMBOL_TLS:
    case SYMBOL_HALF:
      return false;
    }
  gcc_unreachable ();
}
\f
/* Like mips_symbol_insns, but treat extended MIPS16 instructions as a
   single instruction.  We rely on the fact that, in the worst case,
   all instructions involved in a MIPS16 address calculation are usually
   extended ones.  */

static int
mips_symbol_insns_1 (enum mips_symbol_type type, enum machine_mode mode)
{
  switch (type)
    {
    case SYMBOL_ABSOLUTE:
      /* When using 64-bit symbols, we need 5 preparatory instructions,
         such as:

             lui     $at,%highest(symbol)
             daddiu  $at,$at,%higher(symbol)
             dsll    $at,$at,16
             daddiu  $at,$at,%hi(symbol)
             dsll    $at,$at,16

         The final address is then $at + %lo(symbol).  With 32-bit
         symbols we just need a preparatory lui for normal mode and
         a preparatory "li; sll" for MIPS16.  */
      return ABI_HAS_64BIT_SYMBOLS ? 6 : TARGET_MIPS16 ? 3 : 2;

    case SYMBOL_GP_RELATIVE:
      /* Treat GP-relative accesses as taking a single instruction on
         MIPS16 too; the copy of $gp can often be shared.  */
      return 1;

    case SYMBOL_PC_RELATIVE:
      /* PC-relative constants can be only be used with addiupc,
         lwpc and ldpc.  */
      if (mode == MAX_MACHINE_MODE
          || GET_MODE_SIZE (mode) == 4
          || GET_MODE_SIZE (mode) == 8)
        return 1;

      /* The constant must be loaded using addiupc first.  */
      return 0;

    case SYMBOL_FORCE_TO_MEM:
      /* LEAs will be converted into constant-pool references by
         mips_reorg.  */
      if (mode == MAX_MACHINE_MODE)
        return 1;

      /* The constant must be loaded from the constant pool.  */
      return 0;

    case SYMBOL_GOT_DISP:
      /* The constant will have to be loaded from the GOT before it
         is used in an address.  */
      if (mode != MAX_MACHINE_MODE)
        return 0;

      /* Fall through.  */

    case SYMBOL_GOT_PAGE_OFST:
      /* Unless -funit-at-a-time is in effect, we can't be sure whether
         the local/global classification is accurate.  See override_options
         for details.

         The worst cases are:

         (1) For local symbols when generating o32 or o64 code.  The assembler
             will use:

                 lw           $at,%got(symbol)
                 nop

             ...and the final address will be $at + %lo(symbol).

         (2) For global symbols when -mxgot.  The assembler will use:

                 lui     $at,%got_hi(symbol)
                 (d)addu $at,$at,$gp

             ...and the final address will be $at + %got_lo(symbol).  */
      return 3;

    case SYMBOL_GOTOFF_PAGE:
    case SYMBOL_GOTOFF_DISP:
    case SYMBOL_GOTOFF_CALL:
    case SYMBOL_GOTOFF_LOADGP:
    case SYMBOL_32_HIGH:
    case SYMBOL_64_HIGH:
    case SYMBOL_64_MID:
    case SYMBOL_64_LOW:
    case SYMBOL_TLSGD:
    case SYMBOL_TLSLDM:
    case SYMBOL_DTPREL:
    case SYMBOL_GOTTPREL:
    case SYMBOL_TPREL:
    case SYMBOL_HALF:
      /* A 16-bit constant formed by a single relocation, or a 32-bit
         constant formed from a high 16-bit relocation and a low 16-bit
         relocation.  Use mips_split_p to determine which.  */
      return !mips_split_p[type] ? 1 : TARGET_MIPS16 ? 3 : 2;

    case SYMBOL_TLS:
      /* We don't treat a bare TLS symbol as a constant.  */
      return 0;
    }
  gcc_unreachable ();
}

/* If MODE is MAX_MACHINE_MODE, return the number of instructions needed
   to load symbols of type TYPE into a register.  Return 0 if the given
   type of symbol cannot be used as an immediate operand.

   Otherwise, return the number of instructions needed to load or store
   values of mode MODE to or from addresses of type TYPE.  Return 0 if
   the given type of symbol is not valid in addresses.

   In both cases, treat extended MIPS16 instructions as two instructions.  */

static int
mips_symbol_insns (enum mips_symbol_type type, enum machine_mode mode)
{
  return mips_symbol_insns_1 (type, mode) * (TARGET_MIPS16 ? 2 : 1);
}

/* Return true if X can not be forced into a constant pool.  */

static int
mips_tls_symbol_ref_1 (rtx *x, void *data ATTRIBUTE_UNUSED)
{
  return mips_tls_operand_p (*x);
}

/* Return true if X can not be forced into a constant pool.  */

static bool
mips_cannot_force_const_mem (rtx x)
{
  rtx base, offset;

  if (!TARGET_MIPS16)
    {
      /* As an optimization, reject constants that mips_legitimize_move
         can expand inline.

         Suppose we have a multi-instruction sequence that loads constant C
         into register R.  If R does not get allocated a hard register, and
         R is used in an operand that allows both registers and memory
         references, reload will consider forcing C into memory and using
         one of the instruction's memory alternatives.  Returning false
         here will force it to use an input reload instead.  */
      if (GET_CODE (x) == CONST_INT)
        return true;

      split_const (x, &base, &offset);
      if (symbolic_operand (base, VOIDmode) && SMALL_INT (offset))
        return true;
    }

  if (for_each_rtx (&x, &mips_tls_symbol_ref_1, 0))
    return true;

  return false;
}

/* Implement TARGET_USE_BLOCKS_FOR_CONSTANT_P.  We can't use blocks for
   constants when we're using a per-function constant pool.  */

static bool
mips_use_blocks_for_constant_p (enum machine_mode mode ATTRIBUTE_UNUSED,
                                const_rtx x ATTRIBUTE_UNUSED)
{
  return !TARGET_MIPS16_PCREL_LOADS;
}
\f
/* This function is used to implement REG_MODE_OK_FOR_BASE_P.  */

int
mips_regno_mode_ok_for_base_p (int regno, enum machine_mode mode, int strict)
{
  if (!HARD_REGISTER_NUM_P (regno))
    {
      if (!strict)
        return true;
      regno = reg_renumber[regno];
    }

  /* These fake registers will be eliminated to either the stack or
     hard frame pointer, both of which are usually valid base registers.
     Reload deals with the cases where the eliminated form isn't valid.  */
  if (regno == ARG_POINTER_REGNUM || regno == FRAME_POINTER_REGNUM)
    return true;

  /* In mips16 mode, the stack pointer can only address word and doubleword
     values, nothing smaller.  There are two problems here:

       (a) Instantiating virtual registers can introduce new uses of the
           stack pointer.  If these virtual registers are valid addresses,
           the stack pointer should be too.

       (b) Most uses of the stack pointer are not made explicit until
           FRAME_POINTER_REGNUM and ARG_POINTER_REGNUM have been eliminated.
           We don't know until that stage whether we'll be eliminating to the
           stack pointer (which needs the restriction) or the hard frame
           pointer (which doesn't).

     All in all, it seems more consistent to only enforce this restriction
     during and after reload.  */
  if (TARGET_MIPS16 && regno == STACK_POINTER_REGNUM)
    return !strict || GET_MODE_SIZE (mode) == 4 || GET_MODE_SIZE (mode) == 8;

  return TARGET_MIPS16 ? M16_REG_P (regno) : GP_REG_P (regno);
}


/* Return true if X is a valid base register for the given mode.
   Allow only hard registers if STRICT.  */

static bool
mips_valid_base_register_p (rtx x, enum machine_mode mode, int strict)
{
  if (!strict && GET_CODE (x) == SUBREG)
    x = SUBREG_REG (x);

  return (REG_P (x)
          && mips_regno_mode_ok_for_base_p (REGNO (x), mode, strict));
}


/* Return true if X is a valid address for machine mode MODE.  If it is,
   fill in INFO appropriately.  STRICT is true if we should only accept
   hard base registers.  */

static bool
mips_classify_address (struct mips_address_info *info, rtx x,
                       enum machine_mode mode, int strict)
{
  switch (GET_CODE (x))
    {
    case REG:
    case SUBREG:
      info->type = ADDRESS_REG;
      info->reg = x;
      info->offset = const0_rtx;
      return mips_valid_base_register_p (info->reg, mode, strict);

    case PLUS:
      info->type = ADDRESS_REG;
      info->reg = XEXP (x, 0);
      info->offset = XEXP (x, 1);
      return (mips_valid_base_register_p (info->reg, mode, strict)
              && const_arith_operand (info->offset, VOIDmode));

    case LO_SUM:
      info->type = ADDRESS_LO_SUM;
      info->reg = XEXP (x, 0);
      info->offset = XEXP (x, 1);
      /* We have to trust the creator of the LO_SUM to do something vaguely
         sane.  Target-independent code that creates a LO_SUM should also
         create and verify the matching HIGH.  Target-independent code that
         adds an offset to a LO_SUM must prove that the offset will not
         induce a carry.  Failure to do either of these things would be
         a bug, and we are not required to check for it here.  The MIPS
         backend itself should only create LO_SUMs for valid symbolic
         constants, with the high part being either a HIGH or a copy
         of _gp. */
      info->symbol_type
        = mips_classify_symbolic_expression (info->offset, SYMBOL_CONTEXT_MEM);
      return (mips_valid_base_register_p (info->reg, mode, strict)
              && mips_symbol_insns (info->symbol_type, mode) > 0
              && mips_lo_relocs[info->symbol_type] != 0);

    case CONST_INT:
      /* Small-integer addresses don't occur very often, but they
         are legitimate if $0 is a valid base register.  */
      info->type = ADDRESS_CONST_INT;
      return !TARGET_MIPS16 && SMALL_INT (x);

    case CONST:
    case LABEL_REF:
    case SYMBOL_REF:
      info->type = ADDRESS_SYMBOLIC;
      return (mips_symbolic_constant_p (x, SYMBOL_CONTEXT_MEM,
                                        &info->symbol_type)
              && mips_symbol_insns (info->symbol_type, mode) > 0
              && !mips_split_p[info->symbol_type]);

    default:
      return false;
    }
}

/* This function is used to implement GO_IF_LEGITIMATE_ADDRESS.  It
   returns a nonzero value if X is a legitimate address for a memory
   operand of the indicated MODE.  STRICT is nonzero if this function
   is called during reload.  */

bool
mips_legitimate_address_p (enum machine_mode mode, rtx x, int strict)
{
  struct mips_address_info addr;

  return mips_classify_address (&addr, x, mode, strict);
}

/* Return true if X is a legitimate $sp-based address for mode MDOE.  */

bool
mips_stack_address_p (rtx x, enum machine_mode mode)
{
  struct mips_address_info addr;

  return (mips_classify_address (&addr, x, mode, false)
          && addr.type == ADDRESS_REG
          && addr.reg == stack_pointer_rtx);
}

/* Return true if ADDR matches the pattern for the lwxs load scaled indexed
   address instruction.  */

static bool
mips_lwxs_address_p (rtx addr)
{
  if (ISA_HAS_LWXS
      && GET_CODE (addr) == PLUS
      && REG_P (XEXP (addr, 1)))
    {
      rtx offset = XEXP (addr, 0);
      if (GET_CODE (offset) == MULT
          && REG_P (XEXP (offset, 0))
          && GET_CODE (XEXP (offset, 1)) == CONST_INT
          && INTVAL (XEXP (offset, 1)) == 4)
        return true;
    }
  return false;
}

/* Return true if a value at OFFSET bytes from BASE can be accessed
   using an unextended mips16 instruction.  MODE is the mode of the
   value.

   Usually the offset in an unextended instruction is a 5-bit field.
   The offset is unsigned and shifted left once for HIs, twice
   for SIs, and so on.  An exception is SImode accesses off the
   stack pointer, which have an 8-bit immediate field.  */

static bool
mips16_unextended_reference_p (enum machine_mode mode, rtx base, rtx offset)
{
  if (TARGET_MIPS16
      && GET_CODE (offset) == CONST_INT
      && INTVAL (offset) >= 0
      && (INTVAL (offset) & (GET_MODE_SIZE (mode) - 1)) == 0)
    {
      if (GET_MODE_SIZE (mode) == 4 && base == stack_pointer_rtx)
        return INTVAL (offset) < 256 * GET_MODE_SIZE (mode);
      return INTVAL (offset) < 32 * GET_MODE_SIZE (mode);
    }
  return false;
}


/* Return the number of instructions needed to load or store a value
   of mode MODE at X.  Return 0 if X isn't valid for MODE.  Assume that
   multiword moves may need to be split into word moves if MIGHT_SPLIT_P,
   otherwise assume that a single load or store is enough.

   For mips16 code, count extended instructions as two instructions.  */

int
mips_address_insns (rtx x, enum machine_mode mode, bool might_split_p)
{
  struct mips_address_info addr;
  int factor;

  /* BLKmode is used for single unaligned loads and stores and should
     not count as a multiword mode.  (GET_MODE_SIZE (BLKmode) is pretty
     meaningless, so we have to single it out as a special case one way
     or the other.)  */
  if (mode != BLKmode && might_split_p)
    factor = (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
  else
    factor = 1;

  if (mips_classify_address (&addr, x, mode, false))
    switch (addr.type)
      {
      case ADDRESS_REG:
        if (TARGET_MIPS16
            && !mips16_unextended_reference_p (mode, addr.reg, addr.offset))
          return factor * 2;
        return factor;

      case ADDRESS_LO_SUM:
        return (TARGET_MIPS16 ? factor * 2 : factor);

      case ADDRESS_CONST_INT:
        return factor;

      case ADDRESS_SYMBOLIC:
        return factor * mips_symbol_insns (addr.symbol_type, mode);
      }
  return 0;
}


/* Likewise for constant X.  */

int
mips_const_insns (rtx x)
{
  struct mips_integer_op codes[MIPS_MAX_INTEGER_OPS];
  enum mips_symbol_type symbol_type;
  rtx offset;

  switch (GET_CODE (x))
    {
    case HIGH:
      if (!mips_symbolic_constant_p (XEXP (x, 0), SYMBOL_CONTEXT_LEA,
                                     &symbol_type)
          || !mips_split_p[symbol_type])
        return 0;

      /* This is simply an lui for normal mode.  It is an extended
         "li" followed by an extended "sll" for MIPS16.  */
      return TARGET_MIPS16 ? 4 : 1;

    case CONST_INT:
      if (TARGET_MIPS16)
        /* Unsigned 8-bit constants can be loaded using an unextended
           LI instruction.  Unsigned 16-bit constants can be loaded
           using an extended LI.  Negative constants must be loaded
           using LI and then negated.  */
        return (INTVAL (x) >= 0 && INTVAL (x) < 256 ? 1
                : SMALL_OPERAND_UNSIGNED (INTVAL (x)) ? 2
                : INTVAL (x) > -256 && INTVAL (x) < 0 ? 2
                : SMALL_OPERAND_UNSIGNED (-INTVAL (x)) ? 3
                : 0);

      return mips_build_integer (codes, INTVAL (x));

    case CONST_DOUBLE:
    case CONST_VECTOR:
      return (!TARGET_MIPS16 && x == CONST0_RTX (GET_MODE (x)) ? 1 : 0);

    case CONST:
      if (CONST_GP_P (x))
        return 1;

      /* See if we can refer to X directly.  */
      if (mips_symbolic_constant_p (x, SYMBOL_CONTEXT_LEA, &symbol_type))
        return mips_symbol_insns (symbol_type, MAX_MACHINE_MODE);

      /* Otherwise try splitting the constant into a base and offset.
         16-bit offsets can be added using an extra addiu.  Larger offsets
         must be calculated separately and then added to the base.  */
      split_const (x, &x, &offset);
      if (offset != 0)
        {
          int n = mips_const_insns (x);
          if (n != 0)
            {
              if (SMALL_INT (offset))
                return n + 1;
              else
                return n + 1 + mips_build_integer (codes, INTVAL (offset));
            }
        }
      return 0;

    case SYMBOL_REF:
    case LABEL_REF:
      return mips_symbol_insns (mips_classify_symbol (x, SYMBOL_CONTEXT_LEA),
                                MAX_MACHINE_MODE);

    default:
      return 0;
    }
}


/* Return the number of instructions needed to implement INSN,
   given that it loads from or stores to MEM.  Count extended
   mips16 instructions as two instructions.  */

int
mips_load_store_insns (rtx mem, rtx insn)
{
  enum machine_mode mode;
  bool might_split_p;
  rtx set;

  gcc_assert (MEM_P (mem));
  mode = GET_MODE (mem);

  /* Try to prove that INSN does not need to be split.  */
  might_split_p = true;
  if (GET_MODE_BITSIZE (mode) == 64)
    {
      set = single_set (insn);
      if (set && !mips_split_64bit_move_p (SET_DEST (set), SET_SRC (set)))
        might_split_p = false;
    }

  return mips_address_insns (XEXP (mem, 0), mode, might_split_p);
}


/* Return the number of instructions needed for an integer division.  */

int
mips_idiv_insns (void)
{
  int count;

  count = 1;
  if (TARGET_CHECK_ZERO_DIV)
    {
      if (GENERATE_DIVIDE_TRAPS)
        count++;
      else
        count += 2;
    }

  if (TARGET_FIX_R4000 || TARGET_FIX_R4400)
    count++;
  return count;
}
\f
/* Emit a move from SRC to DEST.  Assume that the move expanders can
   handle all moves if !can_create_pseudo_p ().  The distinction is
   important because, unlike emit_move_insn, the move expanders know
   how to force Pmode objects into the constant pool even when the
   constant pool address is not itself legitimate.  */

rtx
mips_emit_move (rtx dest, rtx src)
{
  return (can_create_pseudo_p ()
          ? emit_move_insn (dest, src)
          : emit_move_insn_1 (dest, src));
}

/* Emit an instruction of the form (set TARGET (CODE OP0 OP1)).  */

static void
mips_emit_binary (enum rtx_code code, rtx target, rtx op0, rtx op1)
{
  emit_insn (gen_rtx_SET (VOIDmode, target,
                          gen_rtx_fmt_ee (code, GET_MODE (target), op0, op1)));
}

/* Copy VALUE to a register and return that register.  If new psuedos
   are allowed, copy it into a new register, otherwise use DEST.  */

static rtx
mips_force_temporary (rtx dest, rtx value)
{
  if (can_create_pseudo_p ())
    return force_reg (Pmode, value);
  else
    {
      mips_emit_move (copy_rtx (dest), value);
      return dest;
    }
}

/* If we can access small data directly (using gp-relative relocation
   operators) return the small data pointer, otherwise return null.

   For each mips16 function which refers to GP relative symbols, we
   use a pseudo register, initialized at the start of the function, to
   hold the $gp value.  */

static rtx
mips16_gp_pseudo_reg (void)
{
  if (cfun->machine->mips16_gp_pseudo_rtx == NULL_RTX)
    cfun->machine->mips16_gp_pseudo_rtx = gen_reg_rtx (Pmode);

  /* Don't initialize the pseudo register if we are being called from
     the tree optimizers' cost-calculation routines.  */
  if (!cfun->machine->initialized_mips16_gp_pseudo_p
      && (current_ir_type () != IR_GIMPLE || currently_expanding_to_rtl))
    {
      rtx insn, scan;

      /* We want to initialize this to a value which gcc will believe
         is constant.  */
      insn = gen_load_const_gp (cfun->machine->mips16_gp_pseudo_rtx);

      push_topmost_sequence ();
      /* We need to emit the initialization after the FUNCTION_BEG
         note, so that it will be integrated.  */
      for (scan = get_insns (); scan != NULL_RTX; scan = NEXT_INSN (scan))
        if (NOTE_P (scan)
            && NOTE_KIND (scan) == NOTE_INSN_FUNCTION_BEG)
          break;
      if (scan == NULL_RTX)
        scan = get_insns ();
      insn = emit_insn_after (insn, scan);
      pop_topmost_sequence ();

      cfun->machine->initialized_mips16_gp_pseudo_p = true;
    }

  return cfun->machine->mips16_gp_pseudo_rtx;
}

/* If MODE is MAX_MACHINE_MODE, ADDR appears as a move operand, otherwise
   it appears in a MEM of that mode.  Return true if ADDR is a legitimate
   constant in that context and can be split into a high part and a LO_SUM.
   If so, and if LO_SUM_OUT is nonnull, emit the high part and return
   the LO_SUM in *LO_SUM_OUT.  Leave *LO_SUM_OUT unchanged otherwise.

   TEMP is as for mips_force_temporary and is used to load the high
   part into a register.  */

bool
mips_split_symbol (rtx temp, rtx addr, enum machine_mode mode, rtx *lo_sum_out)
{
  enum mips_symbol_context context;
  enum mips_symbol_type symbol_type;
  rtx high;

  context = (mode == MAX_MACHINE_MODE
             ? SYMBOL_CONTEXT_LEA
             : SYMBOL_CONTEXT_MEM);
  if (!mips_symbolic_constant_p (addr, context, &symbol_type)
      || mips_symbol_insns (symbol_type, mode) == 0
      || !mips_split_p[symbol_type])
    return false;

  if (lo_sum_out)
    {
      if (symbol_type == SYMBOL_GP_RELATIVE)
        {
          if (!can_create_pseudo_p ())
            {
              emit_insn (gen_load_const_gp (copy_rtx (temp)));
              high = temp;
            }
          else
            high = mips16_gp_pseudo_reg ();
        }
      else
        {
          high = gen_rtx_HIGH (Pmode, copy_rtx (addr));
          high = mips_force_temporary (temp, high);
        }
      *lo_sum_out = gen_rtx_LO_SUM (Pmode, high, addr);
    }
  return true;
}


/* Wrap symbol or label BASE in an unspec address of type SYMBOL_TYPE
   and add CONST_INT OFFSET to the result.  */

static rtx
mips_unspec_address_offset (rtx base, rtx offset,
                            enum mips_symbol_type symbol_type)
{
  base = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, base),
                         UNSPEC_ADDRESS_FIRST + symbol_type);
  if (offset != const0_rtx)
    base = gen_rtx_PLUS (Pmode, base, offset);
  return gen_rtx_CONST (Pmode, base);
}

/* Return an UNSPEC address with underlying address ADDRESS and symbol
   type SYMBOL_TYPE.  */

rtx
mips_unspec_address (rtx address, enum mips_symbol_type symbol_type)
{
  rtx base, offset;

  split_const (address, &base, &offset);
  return mips_unspec_address_offset (base, offset, symbol_type);
}


/* If mips_unspec_address (ADDR, SYMBOL_TYPE) is a 32-bit value, add the
   high part to BASE and return the result.  Just return BASE otherwise.
   TEMP is available as a temporary register if needed.

   The returned expression can be used as the first operand to a LO_SUM.  */

static rtx
mips_unspec_offset_high (rtx temp, rtx base, rtx addr,
                         enum mips_symbol_type symbol_type)
{
  if (mips_split_p[symbol_type])
    {
      addr = gen_rtx_HIGH (Pmode, mips_unspec_address (addr, symbol_type));
      addr = mips_force_temporary (temp, addr);
      return mips_force_temporary (temp, gen_rtx_PLUS (Pmode, addr, base));
    }
  return base;
}


/* Return a legitimate address for REG + OFFSET.  TEMP is as for
   mips_force_temporary; it is only needed when OFFSET is not a
   SMALL_OPERAND.  */

static rtx
mips_add_offset (rtx temp, rtx reg, HOST_WIDE_INT offset)
{
  if (!SMALL_OPERAND (offset))
    {
      rtx high;
      if (TARGET_MIPS16)
        {
          /* Load the full offset into a register so that we can use
             an unextended instruction for the address itself.  */
          high = GEN_INT (offset);
          offset = 0;
        }
      else
        {
          /* Leave OFFSET as a 16-bit offset and put the excess in HIGH.  */
          high = GEN_INT (CONST_HIGH_PART (offset));
          offset = CONST_LOW_PART (offset);
        }
      high = mips_force_temporary (temp, high);
      reg = mips_force_temporary (temp, gen_rtx_PLUS (Pmode, high, reg));
    }
  return plus_constant (reg, offset);
}

/* Emit a call to __tls_get_addr.  SYM is the TLS symbol we are
   referencing, and TYPE is the symbol type to use (either global
   dynamic or local dynamic).  V0 is an RTX for the return value
   location.  The entire insn sequence is returned.  */

static GTY(()) rtx mips_tls_symbol;

static rtx
mips_call_tls_get_addr (rtx sym, enum mips_symbol_type type, rtx v0)
{
  rtx insn, loc, tga, a0;

  a0 = gen_rtx_REG (Pmode, GP_ARG_FIRST);

  if (!mips_tls_symbol)
    mips_tls_symbol = init_one_libfunc ("__tls_get_addr");

  loc = mips_unspec_address (sym, type);

  start_sequence ();

  emit_insn (gen_rtx_SET (Pmode, a0,
                          gen_rtx_LO_SUM (Pmode, pic_offset_table_rtx, loc)));
  tga = gen_rtx_MEM (Pmode, mips_tls_symbol);
  insn = emit_call_insn (gen_call_value (v0, tga, const0_rtx, const0_rtx));
  CONST_OR_PURE_CALL_P (insn) = 1;
  use_reg (&CALL_INSN_FUNCTION_USAGE (insn), v0);
  use_reg (&CALL_INSN_FUNCTION_USAGE (insn), a0);
  insn = get_insns ();

  end_sequence ();

  return insn;
}

/* Generate the code to access LOC, a thread local SYMBOL_REF.  The
   return value will be a valid address and move_operand (either a REG
   or a LO_SUM).  */

static rtx
mips_legitimize_tls_address (rtx loc)
{
  rtx dest, insn, v0, v1, tmp1, tmp2, eqv;
  enum tls_model model;

  if (TARGET_MIPS16)
    {
      sorry ("MIPS16 TLS");
      return gen_reg_rtx (Pmode);
    }

  v0 = gen_rtx_REG (Pmode, GP_RETURN);
  v1 = gen_rtx_REG (Pmode, GP_RETURN + 1);

  model = SYMBOL_REF_TLS_MODEL (loc);
  /* Only TARGET_ABICALLS code can have more than one module; other
     code must be be static and should not use a GOT.  All TLS models
     reduce to local exec in this situation.  */
  if (!TARGET_ABICALLS)
    model = TLS_MODEL_LOCAL_EXEC;

  switch (model)
    {
    case TLS_MODEL_GLOBAL_DYNAMIC:
      insn = mips_call_tls_get_addr (loc, SYMBOL_TLSGD, v0);
      dest = gen_reg_rtx (Pmode);
      emit_libcall_block (insn, dest, v0, loc);
      break;

    case TLS_MODEL_LOCAL_DYNAMIC:
      insn = mips_call_tls_get_addr (loc, SYMBOL_TLSLDM, v0);
      tmp1 = gen_reg_rtx (Pmode);

      /* Attach a unique REG_EQUIV, to allow the RTL optimizers to
         share the LDM result with other LD model accesses.  */
      eqv = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, const0_rtx),
                            UNSPEC_TLS_LDM);
      emit_libcall_block (insn, tmp1, v0, eqv);

      tmp2 = mips_unspec_offset_high (NULL, tmp1, loc, SYMBOL_DTPREL);
      dest = gen_rtx_LO_SUM (Pmode, tmp2,
                             mips_unspec_address (loc, SYMBOL_DTPREL));
      break;

    case TLS_MODEL_INITIAL_EXEC:
      tmp1 = gen_reg_rtx (Pmode);
      tmp2 = mips_unspec_address (loc, SYMBOL_GOTTPREL);
      if (Pmode == DImode)
        {
          emit_insn (gen_tls_get_tp_di (v1));
          emit_insn (gen_load_gotdi (tmp1, pic_offset_table_rtx, tmp2));
        }
      else
        {
          emit_insn (gen_tls_get_tp_si (v1));
          emit_insn (gen_load_gotsi (tmp1, pic_offset_table_rtx, tmp2));
        }
      dest = gen_reg_rtx (Pmode);
      emit_insn (gen_add3_insn (dest, tmp1, v1));
      break;

    case TLS_MODEL_LOCAL_EXEC:
      if (Pmode == DImode)
        emit_insn (gen_tls_get_tp_di (v1));
      else
        emit_insn (gen_tls_get_tp_si (v1));

      tmp1 = mips_unspec_offset_high (NULL, v1, loc, SYMBOL_TPREL);
      dest = gen_rtx_LO_SUM (Pmode, tmp1,
                             mips_unspec_address (loc, SYMBOL_TPREL));
      break;

    default:
      gcc_unreachable ();
    }

  return dest;
}

/* This function is used to implement LEGITIMIZE_ADDRESS.  If *XLOC can
   be legitimized in a way that the generic machinery might not expect,
   put the new address in *XLOC and return true.  MODE is the mode of
   the memory being accessed.  */

bool
mips_legitimize_address (rtx *xloc, enum machine_mode mode)
{
  if (mips_tls_operand_p (*xloc))
    {
      *xloc = mips_legitimize_tls_address (*xloc);
      return true;
    }

  /* See if the address can split into a high part and a LO_SUM.  */
  if (mips_split_symbol (NULL, *xloc, mode, xloc))
    return true;

  if (GET_CODE (*xloc) == PLUS && GET_CODE (XEXP (*xloc, 1)) == CONST_INT)
    {
      /* Handle REG + CONSTANT using mips_add_offset.  */
      rtx reg;

      reg = XEXP (*xloc, 0);
      if (!mips_valid_base_register_p (reg, mode, 0))
        reg = copy_to_mode_reg (Pmode, reg);
      *xloc = mips_add_offset (0, reg, INTVAL (XEXP (*xloc, 1)));
      return true;
    }

  return false;
}


/* Load VALUE into DEST, using TEMP as a temporary register if need be.  */

void
mips_move_integer (rtx dest, rtx temp, unsigned HOST_WIDE_INT value)
{
  struct mips_integer_op codes[MIPS_MAX_INTEGER_OPS];
  enum machine_mode mode;
  unsigned int i, cost;
  rtx x;

  mode = GET_MODE (dest);
  cost = mips_build_integer (codes, value);

  /* Apply each binary operation to X.  Invariant: X is a legitimate
     source operand for a SET pattern.  */
  x = GEN_INT (codes[0].value);
  for (i = 1; i < cost; i++)
    {
      if (!can_create_pseudo_p ())
        {
          emit_insn (gen_rtx_SET (VOIDmode, temp, x));
          x = temp;
        }
      else
        x = force_reg (mode, x);
      x = gen_rtx_fmt_ee (codes[i].code, mode, x, GEN_INT (codes[i].value));
    }

  emit_insn (gen_rtx_SET (VOIDmode, dest, x));
}


/* Subroutine of mips_legitimize_move.  Move constant SRC into register
   DEST given that SRC satisfies immediate_operand but doesn't satisfy
   move_operand.  */

static void
mips_legitimize_const_move (enum machine_mode mode, rtx dest, rtx src)
{
  rtx base, offset;

  /* Split moves of big integers into smaller pieces.  */
  if (splittable_const_int_operand (src, mode))
    {
      mips_move_integer (dest, dest, INTVAL (src));
      return;
    }

  /* Split moves of symbolic constants into high/low pairs.  */
  if (mips_split_symbol (dest, src, MAX_MACHINE_MODE, &src))
    {
      emit_insn (gen_rtx_SET (VOIDmode, dest, src));
      return;
    }

  if (mips_tls_operand_p (src))
    {
      mips_emit_move (dest, mips_legitimize_tls_address (src));
      return;
    }

  /* If we have (const (plus symbol offset)), and that expression cannot
     be forced into memory, load the symbol first and add in the offset.
     In non-MIPS16 mode, prefer to do this even if the constant _can_ be
     forced into memory, as it usually produces better code.  */
  split_const (src, &base, &offset);
  if (offset != const0_rtx
      && (targetm.cannot_force_const_mem (src)
          || (!TARGET_MIPS16 && can_create_pseudo_p ())))
    {
      base = mips_force_temporary (dest, base);
      mips_emit_move (dest, mips_add_offset (0, base, INTVAL (offset)));
      return;
    }

  src = force_const_mem (mode, src);

  /* When using explicit relocs, constant pool references are sometimes
     not legitimate addresses.  */
  mips_split_symbol (dest, XEXP (src, 0), mode, &XEXP (src, 0));
  mips_emit_move (dest, src);
}


/* If (set DEST SRC) is not a valid instruction, emit an equivalent
   sequence that is valid.  */

bool
mips_legitimize_move (enum machine_mode mode, rtx dest, rtx src)
{
  if (!register_operand (dest, mode) && !reg_or_0_operand (src, mode))
    {
      mips_emit_move (dest, force_reg (mode, src));
      return true;
    }

  /* Check for individual, fully-reloaded mflo and mfhi instructions.  */
  if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
      && REG_P (src) && MD_REG_P (REGNO (src))
      && REG_P (dest) && GP_REG_P (REGNO (dest)))
    {
      int other_regno = REGNO (src) == HI_REGNUM ? LO_REGNUM : HI_REGNUM;
      if (GET_MODE_SIZE (mode) <= 4)
        emit_insn (gen_mfhilo_si (gen_rtx_REG (SImode, REGNO (dest)),
                                  gen_rtx_REG (SImode, REGNO (src)),
                                  gen_rtx_REG (SImode, other_regno)));
      else
        emit_insn (gen_mfhilo_di (gen_rtx_REG (DImode, REGNO (dest)),
                                  gen_rtx_REG (DImode, REGNO (src)),
                                  gen_rtx_REG (DImode, other_regno)));
      return true;
    }

  /* We need to deal with constants that would be legitimate
     immediate_operands but not legitimate move_operands.  */
  if (CONSTANT_P (src) && !move_operand (src, mode))
    {
      mips_legitimize_const_move (mode, dest, src);
      set_unique_reg_note (get_last_insn (), REG_EQUAL, copy_rtx (src));
      return true;
    }
  return false;
}
\f
/* Return true if X in context CONTEXT is a small data address that can
   be rewritten as a LO_SUM.  */

static bool
mips_rewrite_small_data_p (rtx x, enum mips_symbol_context context)
{
  enum mips_symbol_type symbol_type;

  return (TARGET_EXPLICIT_RELOCS
          && mips_symbolic_constant_p (x, context, &symbol_type)
          && symbol_type == SYMBOL_GP_RELATIVE);
}


/* A for_each_rtx callback for mips_small_data_pattern_p.  DATA is the
   containing MEM, or null if none.  */

static int
mips_small_data_pattern_1 (rtx *loc, void *data)
{
  enum mips_symbol_context context;

  if (GET_CODE (*loc) == LO_SUM)
    return -1;

  if (MEM_P (*loc))
    {
      if (for_each_rtx (&XEXP (*loc, 0), mips_small_data_pattern_1, *loc))
        return 1;
      return -1;
    }

  context = data ? SYMBOL_CONTEXT_MEM : SYMBOL_CONTEXT_LEA;
  return mips_rewrite_small_data_p (*loc, context);
}

/* Return true if OP refers to small data symbols directly, not through
   a LO_SUM.  */

bool
mips_small_data_pattern_p (rtx op)
{
  return for_each_rtx (&op, mips_small_data_pattern_1, 0);
}
\f
/* A for_each_rtx callback, used by mips_rewrite_small_data.
   DATA is the containing MEM, or null if none.  */

static int
mips_rewrite_small_data_1 (rtx *loc, void *data)
{
  enum mips_symbol_context context;

  if (MEM_P (*loc))
    {
      for_each_rtx (&XEXP (*loc, 0), mips_rewrite_small_data_1, *loc);
      return -1;
    }

  context = data ? SYMBOL_CONTEXT_MEM : SYMBOL_CONTEXT_LEA;
  if (mips_rewrite_small_data_p (*loc, context))
    *loc = gen_rtx_LO_SUM (Pmode, pic_offset_table_rtx, *loc);

  if (GET_CODE (*loc) == LO_SUM)
    return -1;

  return 0;
}

/* If possible, rewrite OP so that it refers to small data using
   explicit relocations.  */

rtx
mips_rewrite_small_data (rtx op)
{
  op = copy_insn (op);
  for_each_rtx (&op, mips_rewrite_small_data_1, 0);
  return op;
}
\f
/* We need a lot of little routines to check constant values on the
   mips16.  These are used to figure out how long the instruction will
   be.  It would be much better to do this using constraints, but
   there aren't nearly enough letters available.  */

static int
m16_check_op (rtx op, int low, int high, int mask)
{
  return (GET_CODE (op) == CONST_INT
          && INTVAL (op) >= low
          && INTVAL (op) <= high
          && (INTVAL (op) & mask) == 0);
}

int
m16_uimm3_b (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, 0x1, 0x8, 0);
}

int
m16_simm4_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0x8, 0x7, 0);
}

int
m16_nsimm4_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0x7, 0x8, 0);
}

int
m16_simm5_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0x10, 0xf, 0);
}

int
m16_nsimm5_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0xf, 0x10, 0);
}

int
m16_uimm5_4 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, (- 0x10) << 2, 0xf << 2, 3);
}

int
m16_nuimm5_4 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, (- 0xf) << 2, 0x10 << 2, 3);
}

int
m16_simm8_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0x80, 0x7f, 0);
}

int
m16_nsimm8_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0x7f, 0x80, 0);
}

int
m16_uimm8_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, 0x0, 0xff, 0);
}

int
m16_nuimm8_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0xff, 0x0, 0);
}

int
m16_uimm8_m1_1 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, - 0x1, 0xfe, 0);
}

int
m16_uimm8_4 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, 0x0, 0xff << 2, 3);
}

int
m16_nuimm8_4 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, (- 0xff) << 2, 0x0, 3);
}

int
m16_simm8_8 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, (- 0x80) << 3, 0x7f << 3, 7);
}

int
m16_nsimm8_8 (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
{
  return m16_check_op (op, (- 0x7f) << 3, 0x80 << 3, 7);
}
\f
/* The cost of loading values from the constant pool.  It should be
   larger than the cost of any constant we want to synthesize inline.  */

#define CONSTANT_POOL_COST COSTS_N_INSNS (TARGET_MIPS16 ? 4 : 8)

/* Return the cost of X when used as an operand to the MIPS16 instruction
   that implements CODE.  Return -1 if there is no such instruction, or if
   X is not a valid immediate operand for it.  */

static int
mips16_constant_cost (int code, HOST_WIDE_INT x)
{
  switch (code)
    {
    case ASHIFT:
    case ASHIFTRT:
    case LSHIFTRT:
      /* Shifts by between 1 and 8 bits (inclusive) are unextended,
         other shifts are extended.  The shift patterns truncate the shift
         count to the right size, so there are no out-of-range values.  */
      if (IN_RANGE (x, 1, 8))
        return 0;
      return COSTS_N_INSNS (1);

    case PLUS:
      if (IN_RANGE (x, -128, 127))
        return 0;
      if (SMALL_OPERAND (x))
        return COSTS_N_INSNS (1);
      return -1;

    case LEU:
      /* Like LE, but reject the always-true case.  */
      if (x == -1)
        return -1;
    case LE:
      /* We add 1 to the immediate and use SLT.  */
      x += 1;
    case XOR:
      /* We can use CMPI for an xor with an unsigned 16-bit X.  */
    case LT:
    case LTU:
      if (IN_RANGE (x, 0, 255))
        return 0;
      if (SMALL_OPERAND_UNSIGNED (x))
        return COSTS_N_INSNS (1);
      return -1;

    case EQ:
    case NE:
      /* Equality comparisons with 0 are cheap.  */
      if (x == 0)
        return 0;
      return -1;

    default:
      return -1;
    }
}

/* Return true if there is a non-MIPS16 instruction that implements CODE
   and if that instruction accepts X as an immediate operand.  */

static int
mips_immediate_operand_p (int code, HOST_WIDE_INT x)
{
  switch (code)
    {
    case ASHIFT:
    case ASHIFTRT:
    case LSHIFTRT:
      /* All shift counts are truncated to a valid constant.  */
      return true;

    case ROTATE:
    case ROTATERT:
      /* Likewise rotates, if the target supports rotates at all.  */
      return ISA_HAS_ROR;

    case AND:
    case IOR:
    case XOR:
      /* These instructions take 16-bit unsigned immediates.  */
      return SMALL_OPERAND_UNSIGNED (x);

    case PLUS:
    case LT:
    case LTU:
      /* These instructions take 16-bit signed immediates.  */
      return SMALL_OPERAND (x);

    case EQ:
    case NE:
    case GT:
    case GTU:
      /* The "immediate" forms of these instructions are really
         implemented as comparisons with register 0.  */
      return x == 0;

    case GE:
    case GEU:
      /* Likewise, meaning that the only valid immediate operand is 1.  */
      return x == 1;

    case LE:
      /* We add 1 to the immediate and use SLT.  */
      return SMALL_OPERAND (x + 1);

    case LEU:
      /* Likewise SLTU, but reject the always-true case.  */
      return SMALL_OPERAND (x + 1) && x + 1 != 0;

    case SIGN_EXTRACT:
    case ZERO_EXTRACT:
      /* The bit position and size are immediate operands.  */
      return ISA_HAS_EXT_INS;

    default:
      /* By default assume that $0 can be used for 0.  */
      return x == 0;
    }
}

/* Return the cost of binary operation X, given that the instruction
   sequence for a word-sized or smaller operation has cost SINGLE_COST
   and that the sequence of a double-word operation has cost DOUBLE_COST.  */

static int
mips_binary_cost (rtx x, int single_cost, int double_cost)
{
  int cost;

  if (GET_MODE_SIZE (GET_MODE (x)) == UNITS_PER_WORD * 2)
    cost = double_cost;
  else
    cost = single_cost;
  return (cost
          + rtx_cost (XEXP (x, 0), 0)
          + rtx_cost (XEXP (x, 1), GET_CODE (x)));
}

/* Return the cost of floating-point multiplications of mode MODE.  */

static int
mips_fp_mult_cost (enum machine_mode mode)
{
  return mode == DFmode ? mips_cost->fp_mult_df : mips_cost->fp_mult_sf;
}

/* Return the cost of floating-point divisions of mode MODE.  */

static int
mips_fp_div_cost (enum machine_mode mode)
{
  return mode == DFmode ? mips_cost->fp_div_df : mips_cost->fp_div_sf;
}

/* Return the cost of sign-extending OP to mode MODE, not including the
   cost of OP itself.  */

static int
mips_sign_extend_cost (enum machine_mode mode, rtx op)
{
  if (MEM_P (op))
    /* Extended loads are as cheap as unextended ones.  */
    return 0;

  if (TARGET_64BIT && mode == DImode && GET_MODE (op) == SImode)
    /* A sign extension from SImode to DImode in 64-bit mode is free.  */
    return 0;

  if (ISA_HAS_SEB_SEH || GENERATE_MIPS16E)
    /* We can use SEB or SEH.  */
    return COSTS_N_INSNS (1);

  /* We need to use a shift left and a shift right.  */
  return COSTS_N_INSNS (TARGET_MIPS16 ? 4 : 2);
}

/* Return the cost of zero-extending OP to mode MODE, not including the
   cost of OP itself.  */

static int
mips_zero_extend_cost (enum machine_mode mode, rtx op)
{
  if (MEM_P (op))
    /* Extended loads are as cheap as unextended ones.  */
    return 0;

  if (TARGET_64BIT && mode == DImode && GET_MODE (op) == SImode)
    /* We need a shift left by 32 bits and a shift right by 32 bits.  */
    return COSTS_N_INSNS (TARGET_MIPS16 ? 4 : 2);

  if (GENERATE_MIPS16E)
    /* We can use ZEB or ZEH.  */
    return COSTS_N_INSNS (1);

  if (TARGET_MIPS16)
    /* We need to load 0xff or 0xffff into a register and use AND.  */
    return COSTS_N_INSNS (GET_MODE (op) == QImode ? 2 : 3);

  /* We can use ANDI.  */
  return COSTS_N_INSNS (1);
}

/* Implement TARGET_RTX_COSTS.  */

static bool
mips_rtx_costs (rtx x, int code, int outer_code, int *total)
{
  enum machine_mode mode = GET_MODE (x);
  bool float_mode_p = FLOAT_MODE_P (mode);
  int cost;
  rtx addr;

  /* The cost of a COMPARE is hard to define for MIPS.  COMPAREs don't
     appear in the instruction stream, and the cost of a comparison is
     really the cost of the branch or scc condition.  At the time of
     writing, gcc only uses an explicit outer COMPARE code when optabs
     is testing whether a constant is expensive enough to force into a
     register.  We want optabs to pass such constants through the MIPS
     expanders instead, so make all constants very cheap here.  */
  if (outer_code == COMPARE)
    {
      gcc_assert (CONSTANT_P (x));
      *total = 0;
      return true;
    }

  switch (code)
    {
    case CONST_INT:
      /* Treat *clear_upper32-style ANDs as having zero cost in the
         second operand.  The cost is entirely in the first operand.

         ??? This is needed because we would otherwise try to CSE
         the constant operand.  Although that's the right thing for
         instructions that continue to be a register operation throughout
         compilation, it is disastrous for instructions that could
         later be converted into a memory operation.  */
      if (TARGET_64BIT
          && outer_code == AND
          && UINTVAL (x) == 0xffffffff)
        {
          *total = 0;
          return true;
        }

      if (TARGET_MIPS16)
        {
          cost = mips16_constant_cost (outer_code, INTVAL (x));
          if (cost >= 0)
            {
              *total = cost;
              return true;
            }
        }
      else
        {
          /* When not optimizing for size, we care more about the cost
             of hot code, and hot code is often in a loop.  If a constant
             operand needs to be forced into a register, we will often be
             able to hoist the constant load out of the loop, so the load
             should not contribute to the cost.  */
          if (!optimize_size
              || mips_immediate_operand_p (outer_code, INTVAL (x)))
            {
              *total = 0;
              return true;
            }
        }
      /* Fall through.  */

    case CONST:
    case SYMBOL_REF:
    case LABEL_REF:
    case CONST_DOUBLE:
      if (force_to_mem_operand (x, VOIDmode))
        {
          *total = COSTS_N_INSNS (1);
          return true;
        }
      cost = mips_const_insns (x);
      if (cost > 0)
        {
          /* If the constant is likely to be stored in a GPR, SETs of
             single-insn constants are as cheap as register sets; we
             never want to CSE them.

             Don't reduce the cost of storing a floating-point zero in
             FPRs.  If we have a zero in an FPR for other reasons, we
             can get better cfg-cleanup and delayed-branch results by
             using it consistently, rather than using $0 sometimes and
             an FPR at other times.  Also, moves between floating-point
             registers are sometimes cheaper than (D)MTC1 $0.  */
          if (cost == 1
              && outer_code == SET
              && !(float_mode_p && TARGET_HARD_FLOAT))
            cost = 0;
          /* When non-MIPS16 code loads a constant N>1 times, we rarely
             want to CSE the constant itself.  It is usually better to
             have N copies of the last operation in the sequence and one
             shared copy of the other operations.  (Note that this is
             not true for MIPS16 code, where the final operation in the
             sequence is often an extended instruction.)

             Also, if we have a CONST_INT, we don't know whether it is
             for a word or doubleword operation, so we cannot rely on
             the result of mips_build_integer.  */
          else if (!TARGET_MIPS16
                   && (outer_code == SET || mode == VOIDmode))
            cost = 1;
          *total = COSTS_N_INSNS (cost);
          return true;
        }
      /* The value will need to be fetched from the constant pool.  */
      *total = CONSTANT_POOL_COST;
      return true;

    case MEM:
      /* If the address is legitimate, return the number of
         instructions it needs.  */
      addr = XEXP (x, 0);
      cost = mips_address_insns (addr, mode, true);
      if (cost > 0)
        {
          *total = COSTS_N_INSNS (cost + 1);
          return true;
        }
      /* Check for a scaled indexed address.  */
      if (mips_lwxs_address_p (addr))
        {
          *total = COSTS_N_INSNS (2);
          return true;
        }
      /* Otherwise use the default handling.  */
      return false;

    case FFS:
      *total = COSTS_N_INSNS (6);
      return false;

    case NOT:
      *total = COSTS_N_INSNS (GET_MODE_SIZE (mode) > UNITS_PER_WORD ? 2 : 1);
      return false;

    case AND:
      /* Check for a *clear_upper32 pattern and treat it like a zero
         extension.  See the pattern's comment for details.  */
      if (TARGET_64BIT
          && mode == DImode
          && CONST_INT_P (XEXP (x, 1))
          && UINTVAL (XEXP (x, 1)) == 0xffffffff)
        {
          *total = (mips_zero_extend_cost (mode, XEXP (x, 0))
                    + rtx_cost (XEXP (x, 0), 0));
          return true;
        }
      /* Fall through.  */

    case IOR:
    case XOR:
      /* Double-word operations use two single-word operations.  */
      *total = mips_binary_cost (x, COSTS_N_INSNS (1), COSTS_N_INSNS (2));
      return true;

    case ASHIFT:
    case ASHIFTRT:
    case LSHIFTRT:
    case ROTATE:
    case ROTATERT:
      if (CONSTANT_P (XEXP (x, 1)))
        *total = mips_binary_cost (x, COSTS_N_INSNS (1), COSTS_N_INSNS (4));
      else
        *total = mips_binary_cost (x, COSTS_N_INSNS (1), COSTS_N_INSNS (12));
      return true;

    case ABS:
      if (float_mode_p)
        *total = mips_cost->fp_add;
      else
        *total = COSTS_N_INSNS (4);
      return false;

    case LO_SUM:
      /* Low-part immediates need an extended MIPS16 instruction.  */
      *total = (COSTS_N_INSNS (TARGET_MIPS16 ? 2 : 1)
                + rtx_cost (XEXP (x, 0), 0));
      return true;

    case LT:
    case LTU:
    case LE:
    case LEU:
    case GT:
    case GTU:
    case GE:
    case GEU:
    case EQ:
    case NE:
    case UNORDERED:
    case LTGT:
      /* Branch comparisons have VOIDmode, so use the first operand's
         mode instead.  */
      mode = GET_MODE (XEXP (x, 0));
      if (FLOAT_MODE_P (mode))
        {
          *total = mips_cost->fp_add;
          return false;
        }
      *total = mips_binary_cost (x, COSTS_N_INSNS (1), COSTS_N_INSNS (4));
      return true;

    case MINUS:
      if (float_mode_p
          && ISA_HAS_NMADD_NMSUB
          && TARGET_FUSED_MADD
          && !HONOR_NANS (mode)
          && !HONOR_SIGNED_ZEROS (mode))
        {
          /* See if we can use NMADD or NMSUB.  See mips.md for the
             associated patterns.  */
          rtx op0 = XEXP (x, 0);
          rtx op1 = XEXP (x, 1);
          if (GET_CODE (op0) == MULT && GET_CODE (XEXP (op0, 0)) == NEG)
            {
              *total = (mips_fp_mult_cost (mode)
                        + rtx_cost (XEXP (XEXP (op0, 0), 0), 0)
                        + rtx_cost (XEXP (op0, 1), 0)
                        + rtx_cost (op1, 0));
              return true;
            }
          if (GET_CODE (op1) == MULT)
            {
              *total = (mips_fp_mult_cost (mode)
                        + rtx_cost (op0, 0)
                        + rtx_cost (XEXP (op1, 0), 0)
                        + rtx_cost (XEXP (op1, 1), 0));
              return true;
            }
        }
      /* Fall through.  */

    case PLUS:
      if (float_mode_p)
        {
          if (ISA_HAS_FP4
              && TARGET_FUSED_MADD
              && GET_CODE (XEXP (x, 0)) == MULT)
            *total = 0;
          else
            *total = mips_cost->fp_add;
          return false;
        }

      /* Double-word operations require three single-word operations and
         an SLTU.  The MIPS16 version then needs to move the result of
         the SLTU from $24 to a MIPS16 register.  */
      *total = mips_binary_cost (x, COSTS_N_INSNS (1),
                                 COSTS_N_INSNS (TARGET_MIPS16 ? 5 : 4));
      return true;

    case NEG:
      if (float_mode_p
          && ISA_HAS_NMADD_NMSUB
          && TARGET_FUSED_MADD
          && !HONOR_NANS (mode)
          && HONOR_SIGNED_ZEROS (mode))
        {
          /* See if we can use NMADD or NMSUB.  See mips.md for the
             associated patterns.  */
          rtx op = XEXP (x, 0);
          if ((GET_CODE (op) == PLUS || GET_CODE (op) == MINUS)
              && GET_CODE (XEXP (op, 0)) == MULT)
            {
              *total = (mips_fp_mult_cost (mode)
                        + rtx_cost (XEXP (XEXP (op, 0), 0), 0)
                        + rtx_cost (XEXP (XEXP (op, 0), 1), 0)
                        + rtx_cost (XEXP (op, 1), 0));
              return true;
            }
        }

      if (float_mode_p)
        *total = mips_cost->fp_add;
      else
        *total = COSTS_N_INSNS (GET_MODE_SIZE (mode) > UNITS_PER_WORD ? 4 : 1);
      return false;

    case MULT:
      if (float_mode_p)
        *total = mips_fp_mult_cost (mode);
      else if (mode == DImode && !TARGET_64BIT)
        /* Synthesized from 2 mulsi3s, 1 mulsidi3 and two additions,
           where the mulsidi3 always includes an MFHI and an MFLO.  */
        *total = (optimize_size
                  ? COSTS_N_INSNS (ISA_HAS_MUL3 ? 7 : 9)
                  : mips_cost->int_mult_si * 3 + 6);
      else if (optimize_size)
        *total = (ISA_HAS_MUL3 ? 1 : 2);
      else if (mode == DImode)
        *total = mips_cost->int_mult_di;
      else
        *total = mips_cost->int_mult_si;
      return false;

    case DIV:
      /* Check for a reciprocal.  */
      if (float_mode_p && XEXP (x, 0) == CONST1_RTX (mode))
        {
          if (ISA_HAS_FP4
              && flag_unsafe_math_optimizations
              && (outer_code == SQRT || GET_CODE (XEXP (x, 1)) == SQRT))
            {
              /* An rsqrt<mode>a or rsqrt<mode>b pattern.  Count the
                 division as being free.  */
              *total = rtx_cost (XEXP (x, 1), 0);
              return true;
            }
          if (!ISA_MIPS1)
            {
              *total = mips_fp_div_cost (mode) + rtx_cost (XEXP (x, 1), 0);
              return true;
            }
        }
      /* Fall through.  */

    case SQRT:
    case MOD:
      if (float_mode_p)
        {
          *total = mips_fp_div_cost (mode);
          return false;
        }
      /* Fall through.  */

    case UDIV:
    case UMOD:
      if (optimize_size)
        {
          /* It is our responsibility to make division by a power of 2
             as cheap as 2 register additions if we want the division
             expanders to be used for such operations; see the setting
             of sdiv_pow2_cheap in optabs.c.  Using (D)DIV for MIPS16
             should always produce shorter code than using
             expand_sdiv2_pow2.  */
          if (TARGET_MIPS16
              && CONST_INT_P (XEXP (x, 1))
              && exact_log2 (INTVAL (XEXP (x, 1))) >= 0)
            {
              *total = COSTS_N_INSNS (2) + rtx_cost (XEXP (x, 0), 0);
              return true;
            }
          *total = COSTS_N_INSNS (mips_idiv_insns ());
        }
      else if (mode == DImode)
        *total = mips_cost->int_div_di;
      else
        *total = mips_cost->int_div_si;
      return false;

    case SIGN_EXTEND:
      *total = mips_sign_extend_cost (mode, XEXP (x, 0));
      return false;

    case ZERO_EXTEND:
      *total = mips_zero_extend_cost (mode, XEXP (x, 0));
      return false;

    case FLOAT:
    case UNSIGNED_FLOAT:
    case FIX:
    case FLOAT_EXTEND:
    case FLOAT_TRUNCATE:
      *total = mips_cost->fp_add;
      return false;

    default:
      return false;
    }
}

/* Provide the costs of an addressing mode that contains ADDR.
   If ADDR is not a valid address, its cost is irrelevant.  */

static int
mips_address_cost (rtx addr)
{
  return mips_address_insns (addr, SImode, false);
}
\f
/* Return one word of double-word value OP, taking into account the fixed
   endianness of certain registers.  HIGH_P is true to select the high part,
   false to select the low part.  */

rtx
mips_subword (rtx op, int high_p)
{
  unsigned int byte, offset;
  enum machine_mode mode;

  mode = GET_MODE (op);
  if (mode == VOIDmode)
    mode = DImode;

  if (TARGET_BIG_ENDIAN ? !high_p : high_p)
    byte = UNITS_PER_WORD;
  else
    byte = 0;

  if (FP_REG_RTX_P (op))
    {
      /* Paired FPRs are always ordered little-endian.  */
      offset = (UNITS_PER_WORD < UNITS_PER_HWFPVALUE ? high_p : byte != 0);
      return gen_rtx_REG (word_mode, REGNO (op) + offset);
    }

  if (MEM_P (op))
    return mips_rewrite_small_data (adjust_address (op, word_mode, byte));

  return simplify_gen_subreg (word_mode, op, mode, byte);
}


/* Return true if a 64-bit move from SRC to DEST should be split into two.  */

bool
mips_split_64bit_move_p (rtx dest, rtx src)
{
  if (TARGET_64BIT)
    return false;

  /* FP->FP moves can be done in a single instruction.  */
  if (FP_REG_RTX_P (src) && FP_REG_RTX_P (dest))
    return false;

  /* Check for floating-point loads and stores.  They can be done using
     ldc1 and sdc1 on MIPS II and above.  */
  if (mips_isa > 1)
    {
      if (FP_REG_RTX_P (dest) && MEM_P (src))
        return false;
      if (FP_REG_RTX_P (src) && MEM_P (dest))
        return false;
    }
  return true;
}


/* Split a doubleword move from SRC to DEST.  On 32-bit targets,
   this function handles 64-bit moves for which mips_split_64bit_move_p
   holds.  For 64-bit targets, this function handles 128-bit moves.  */

void
mips_split_doubleword_move (rtx dest, rtx src)
{
  if (FP_REG_RTX_P (dest) || FP_REG_RTX_P (src))
    {
      if (!TARGET_64BIT && GET_MODE (dest) == DImode)
        emit_insn (gen_move_doubleword_fprdi (dest, src));
      else if (!TARGET_64BIT && GET_MODE (dest) == DFmode)
        emit_insn (gen_move_doubleword_fprdf (dest, src));
      else if (TARGET_64BIT && GET_MODE (dest) == TFmode)
        emit_insn (gen_move_doubleword_fprtf (dest, src));
      else
        gcc_unreachable ();
    }
  else
    {
      /* The operation can be split into two normal moves.  Decide in
         which order to do them.  */
      rtx low_dest;

      low_dest = mips_subword (dest, 0);
      if (REG_P (low_dest)
          && reg_overlap_mentioned_p (low_dest, src))
        {
          mips_emit_move (mips_subword (dest, 1), mips_subword (src, 1));
          mips_emit_move (low_dest, mips_subword (src, 0));
        }
      else
        {
          mips_emit_move (low_dest, mips_subword (src, 0));
          mips_emit_move (mips_subword (dest, 1), mips_subword (src, 1));
        }
    }
}
\f
/* Return the appropriate instructions to move SRC into DEST.  Assume
   that SRC is operand 1 and DEST is operand 0.  */

const char *
mips_output_move (rtx dest, rtx src)
{
  enum rtx_code dest_code, src_code;
  enum mips_symbol_type symbol_type;
  bool dbl_p;

  dest_code = GET_CODE (dest);
  src_code = GET_CODE (src);
  dbl_p = (GET_MODE_SIZE (GET_MODE (dest)) == 8);

  if (dbl_p && mips_split_64bit_move_p (dest, src))
    return "#";

  if ((src_code == REG && GP_REG_P (REGNO (src)))
      || (!TARGET_MIPS16 && src == CONST0_RTX (GET_MODE (dest))))
    {
      if (dest_code == REG)
        {
          if (GP_REG_P (REGNO (dest)))
            return "move\t%0,%z1";

          if (MD_REG_P (REGNO (dest)))
            return "mt%0\t%z1";

          if (DSP_ACC_REG_P (REGNO (dest)))
            {
              static char retval[] = "mt__\t%z1,%q0";
              retval[2] = reg_names[REGNO (dest)][4];
              retval[3] = reg_names[REGNO (dest)][5];
              return retval;
            }

          if (FP_REG_P (REGNO (dest)))
            return (dbl_p ? "dmtc1\t%z1,%0" : "mtc1\t%z1,%0");

          if (ALL_COP_REG_P (REGNO (dest)))
            {
              static char retval[] = "dmtc_\t%z1,%0";

              retval[4] = COPNUM_AS_CHAR_FROM_REGNUM (REGNO (dest));
              return (dbl_p ? retval : retval + 1);
            }
        }
      if (dest_code == MEM)
        return (dbl_p ? "sd\t%z1,%0" : "sw\t%z1,%0");
    }
  if (dest_code == REG && GP_REG_P (REGNO (dest)))
    {
      if (src_code == REG)
        {
          if (DSP_ACC_REG_P (REGNO (src)))
            {
              static char retval[] = "mf__\t%0,%q1";
              retval[2] = reg_names[REGNO (src)][4];
              retval[3] = reg_names[REGNO (src)][5];
              return retval;
            }

          if (ST_REG_P (REGNO (src)) && ISA_HAS_8CC)
            return "lui\t%0,0x3f80\n\tmovf\t%0,%.,%1";

          if (FP_REG_P (REGNO (src)))
            return (dbl_p ? "dmfc1\t%0,%1" : "mfc1\t%0,%1");

          if (ALL_COP_REG_P (REGNO (src)))
            {
              static char retval[] = "dmfc_\t%0,%1";

              retval[4] = COPNUM_AS_CHAR_FROM_REGNUM (REGNO (src));
              return (dbl_p ? retval : retval + 1);
            }
        }

      if (src_code == MEM)
        return (dbl_p ? "ld\t%0,%1" : "lw\t%0,%1");

      if (src_code == CONST_INT)
        {
          /* Don't use the X format, because that will give out of
             range numbers for 64-bit hosts and 32-bit targets.  */
          if (!TARGET_MIPS16)
            return "li\t%0,%1\t\t\t# %X1";

          if (INTVAL (src) >= 0 && INTVAL (src) <= 0xffff)
            return "li\t%0,%1";

          if (INTVAL (src) < 0 && INTVAL (src) >= -0xffff)
            return "#";
        }

      if (src_code == HIGH)
        return TARGET_MIPS16 ? "#" : "lui\t%0,%h1";

      if (CONST_GP_P (src))
        return "move\t%0,%1";

      if (mips_symbolic_constant_p (src, SYMBOL_CONTEXT_LEA, &symbol_type)
          && mips_lo_relocs[symbol_type] != 0)
        {
          /* A signed 16-bit constant formed by applying a relocation
             operator to a symbolic address.  */
          gcc_assert (!mips_split_p[symbol_type]);
          return "li\t%0,%R1";
        }

      if (symbolic_operand (src, VOIDmode))
        {
          gcc_assert (TARGET_MIPS16
                      ? TARGET_MIPS16_TEXT_LOADS
                      : !TARGET_EXPLICIT_RELOCS);
          return (dbl_p ? "dla\t%0,%1" : "la\t%0,%1");
        }
    }
  if (src_code == REG && FP_REG_P (REGNO (src)))
    {
      if (dest_code == REG && FP_REG_P (REGNO (dest)))
        {
          if (GET_MODE (dest) == V2SFmode)
            return "mov.ps\t%0,%1";
          else
            return (dbl_p ? "mov.d\t%0,%1" : "mov.s\t%0,%1");
        }

      if (dest_code == MEM)
        return (dbl_p ? "sdc1\t%1,%0" : "swc1\t%1,%0");
    }
  if (dest_code == REG && FP_REG_P (REGNO (dest)))
    {
      if (src_code == MEM)
        return (dbl_p ? "ldc1\t%0,%1" : "lwc1\t%0,%1");
    }
  if (dest_code == REG && ALL_COP_REG_P (REGNO (dest)) && src_code == MEM)
    {
      static char retval[] = "l_c_\t%0,%1";

      retval[1] = (dbl_p ? 'd' : 'w');
      retval[3] = COPNUM_AS_CHAR_FROM_REGNUM (REGNO (dest));
      return retval;
    }
  if (dest_code == MEM && src_code == REG && ALL_COP_REG_P (REGNO (src)))
    {
      static char retval[] = "s_c_\t%1,%0";

      retval[1] = (dbl_p ? 'd' : 'w');
      retval[3] = COPNUM_AS_CHAR_FROM_REGNUM (REGNO (src));
      return retval;
    }
  gcc_unreachable ();
}
\f
/* Return true if CMP1 is a suitable second operand for relational
   operator CODE.  See also the *sCC patterns in mips.md.  */

static bool
mips_relational_operand_ok_p (enum rtx_code code, rtx cmp1)
{
  switch (code)
    {
    case GT:
    case GTU:
      return reg_or_0_operand (cmp1, VOIDmode);

    case GE:
    case GEU:
      return !TARGET_MIPS16 && cmp1 == const1_rtx;

    case LT:
    case LTU:
      return arith_operand (cmp1, VOIDmode);

    case LE:
      return sle_operand (cmp1, VOIDmode);

    case LEU:
      return sleu_operand (cmp1, VOIDmode);

    default:
      gcc_unreachable ();
    }
}

/* Canonicalize LE or LEU comparisons into LT comparisons when
   possible to avoid extra instructions or inverting the
   comparison.  */

static bool
mips_canonicalize_comparison (enum rtx_code *code, rtx *cmp1,
                              enum machine_mode mode)
{
  HOST_WIDE_INT original, plus_one;

  if (GET_CODE (*cmp1) != CONST_INT)
    return false;

  original = INTVAL (*cmp1);
  plus_one = trunc_int_for_mode ((unsigned HOST_WIDE_INT) original + 1, mode);

  switch (*code)
    {
    case LE:
      if (original < plus_one)
        {
          *code = LT;
          *cmp1 = force_reg (mode, GEN_INT (plus_one));
          return true;
        }
      break;

    case LEU:
      if (plus_one != 0)
        {
          *code = LTU;
          *cmp1 = force_reg (mode, GEN_INT (plus_one));
          return true;
        }
      break;

    default:
      return false;
   }

  return false;

}

/* Compare CMP0 and CMP1 using relational operator CODE and store the
   result in TARGET.  CMP0 and TARGET are register_operands that have
   the same integer mode.  If INVERT_PTR is nonnull, it's OK to set
   TARGET to the inverse of the result and flip *INVERT_PTR instead.  */

static void
mips_emit_int_relational (enum rtx_code code, bool *invert_ptr,
                          rtx target, rtx cmp0, rtx cmp1)
{
  /* First see if there is a MIPS instruction that can do this operation
     with CMP1 in its current form. If not, try to canonicalize the
     comparison to LT. If that fails, try doing the same for the
     inverse operation.  If that also fails, force CMP1 into a register
     and try again.  */
  if (mips_relational_operand_ok_p (code, cmp1))
    mips_emit_binary (code, target, cmp0, cmp1);
  else if (mips_canonicalize_comparison (&code, &cmp1, GET_MODE (target)))
    mips_emit_binary (code, target, cmp0, cmp1);
  else
    {
      enum rtx_code inv_code = reverse_condition (code);
      if (!mips_relational_operand_ok_p (inv_code, cmp1))
        {
          cmp1 = force_reg (GET_MODE (cmp0), cmp1);
          mips_emit_int_relational (code, invert_ptr, target, cmp0, cmp1);
        }
      else if (invert_ptr == 0)
        {
          rtx inv_target = gen_reg_rtx (GET_MODE (target));
          mips_emit_binary (inv_code, inv_target, cmp0, cmp1);
          mips_emit_binary (XOR, target, inv_target, const1_rtx);
        }
      else
        {
          *invert_ptr = !*invert_ptr;
          mips_emit_binary (inv_code, target, cmp0, cmp1);
        }
    }
}

/* Return a register that is zero iff CMP0 and CMP1 are equal.
   The register will have the same mode as CMP0.  */

static rtx
mips_zero_if_equal (rtx cmp0, rtx cmp1)
{
  if (cmp1 == const0_rtx)
    return cmp0;

  if (uns_arith_operand (cmp1, VOIDmode))
    return expand_binop (GET_MODE (cmp0), xor_optab,
                         cmp0, cmp1, 0, 0, OPTAB_DIRECT);

  return expand_binop (GET_MODE (cmp0), sub_optab,
                       cmp0, cmp1, 0, 0, OPTAB_DIRECT);
}

/* Convert *CODE into a code that can be used in a floating-point
   scc instruction (c.<cond>.<fmt>).  Return true if the values of
   the condition code registers will be inverted, with 0 indicating
   that the condition holds.  */

static bool
mips_reverse_fp_cond_p (enum rtx_code *code)
{
  switch (*code)
    {
    case NE:
    case LTGT:
    case ORDERED:
      *code = reverse_condition_maybe_unordered (*code);
      return true;

    default:
      return false;
    }
}

/* Convert a comparison into something that can be used in a branch or
   conditional move.  cmp_operands[0] and cmp_operands[1] are the values
   being compared and *CODE is the code used to compare them.

   Update *CODE, *OP0 and *OP1 so that they describe the final comparison.
   If NEED_EQ_NE_P, then only EQ/NE comparisons against zero are possible,
   otherwise any standard branch condition can be used.  The standard branch
   conditions are:

      - EQ/NE between two registers.
      - any comparison between a register and zero.  */

static void
mips_emit_compare (enum rtx_code *code, rtx *op0, rtx *op1, bool need_eq_ne_p)
{
  if (GET_MODE_CLASS (GET_MODE (cmp_operands[0])) == MODE_INT)
    {
      if (!need_eq_ne_p && cmp_operands[1] == const0_rtx)
        {
          *op0 = cmp_operands[0];
          *op1 = cmp_operands[1];
        }
      else if (*code == EQ || *code == NE)
        {
          if (need_eq_ne_p)
            {
              *op0 = mips_zero_if_equal (cmp_operands[0], cmp_operands[1]);
              *op1 = const0_rtx;
            }
          else
            {
              *op0 = cmp_operands[0];
              *op1 = force_reg (GET_MODE (*op0), cmp_operands[1]);
            }
        }
      else
        {
          /* The comparison needs a separate scc instruction.  Store the
             result of the scc in *OP0 and compare it against zero.  */
          bool invert = false;
          *op0 = gen_reg_rtx (GET_MODE (cmp_operands[0]));
          *op1 = const0_rtx;
          mips_emit_int_relational (*code, &invert, *op0,
                                    cmp_operands[0], cmp_operands[1]);
          *code = (invert ? EQ : NE);
        }
    }
  else if (ALL_FIXED_POINT_MODE_P (GET_MODE (cmp_operands[0])))
    {
      *op0 = gen_rtx_REG (CCDSPmode, CCDSP_CC_REGNUM);
      mips_emit_binary (*code, *op0, cmp_operands[0], cmp_operands[1]);
      *code = NE;
      *op1 = const0_rtx;
    }
  else
    {
      enum rtx_code cmp_code;

      /* Floating-point tests use a separate c.cond.fmt comparison to
         set a condition code register.  The branch or conditional move
         will then compare that register against zero.

         Set CMP_CODE to the code of the comparison instruction and
         *CODE to the code that the branch or move should use.  */
      cmp_code = *code;
      *code = mips_reverse_fp_cond_p (&cmp_code) ? EQ : NE;
      *op0 = (ISA_HAS_8CC
              ? gen_reg_rtx (CCmode)
              : gen_rtx_REG (CCmode, FPSW_REGNUM));
      *op1 = const0_rtx;
      mips_emit_binary (cmp_code, *op0, cmp_operands[0], cmp_operands[1]);
    }
}
\f
/* Try comparing cmp_operands[0] and cmp_operands[1] using rtl code CODE.
   Store the result in TARGET and return true if successful.

   On 64-bit targets, TARGET may be wider than cmp_operands[0].  */

bool
mips_emit_scc (enum rtx_code code, rtx target)
{
  if (GET_MODE_CLASS (GET_MODE (cmp_operands[0])) != MODE_INT)
    return false;

  target = gen_lowpart (GET_MODE (cmp_operands[0]), target);
  if (code == EQ || code == NE)
    {
      rtx zie = mips_zero_if_equal (cmp_operands[0], cmp_operands[1]);
      mips_emit_binary (code, target, zie, const0_rtx);
    }
  else
    mips_emit_int_relational (code, 0, target,
                              cmp_operands[0], cmp_operands[1]);
  return true;
}

/* Emit the common code for doing conditional branches.
   operand[0] is the label to jump to.
   The comparison operands are saved away by cmp{si,di,sf,df}.  */

void
gen_conditional_branch (rtx *operands, enum rtx_code code)
{
  rtx op0, op1, condition;

  mips_emit_compare (&code, &op0, &op1, TARGET_MIPS16);
  condition = gen_rtx_fmt_ee (code, VOIDmode, op0, op1);
  emit_jump_insn (gen_condjump (condition, operands[0]));
}

/* Implement:

   (set temp (COND:CCV2 CMP_OP0 CMP_OP1))
   (set DEST (unspec [TRUE_SRC FALSE_SRC temp] UNSPEC_MOVE_TF_PS))  */

void
mips_expand_vcondv2sf (rtx dest, rtx true_src, rtx false_src,
                       enum rtx_code cond, rtx cmp_op0, rtx cmp_op1)
{
  rtx cmp_result;
  bool reversed_p;

  reversed_p = mips_reverse_fp_cond_p (&cond);
  cmp_result = gen_reg_rtx (CCV2mode);
  emit_insn (gen_scc_ps (cmp_result,
                         gen_rtx_fmt_ee (cond, VOIDmode, cmp_op0, cmp_op1)));
  if (reversed_p)
    emit_insn (gen_mips_cond_move_tf_ps (dest, false_src, true_src,
                                         cmp_result));
  else
    emit_insn (gen_mips_cond_move_tf_ps (dest, true_src, false_src,
                                         cmp_result));
}

/* Emit the common code for conditional moves.  OPERANDS is the array
   of operands passed to the conditional move define_expand.  */

void
gen_conditional_move (rtx *operands)
{
  enum rtx_code code;
  rtx op0, op1;

  code = GET_CODE (operands[1]);
  mips_emit_compare (&code, &op0, &op1, true);
  emit_insn (gen_rtx_SET (VOIDmode, operands[0],
                          gen_rtx_IF_THEN_ELSE (GET_MODE (operands[0]),
                                                gen_rtx_fmt_ee (code,
                                                                GET_MODE (op0),
                                                                op0, op1),
                                                operands[2], operands[3])));
}

/* Emit a conditional trap.  OPERANDS is the array of operands passed to
   the conditional_trap expander.  */

void
mips_gen_conditional_trap (rtx *operands)
{
  rtx op0, op1;
  enum rtx_code cmp_code = GET_CODE (operands[0]);
  enum machine_mode mode = GET_MODE (cmp_operands[0]);

  /* MIPS conditional trap machine instructions don't have GT or LE
     flavors, so we must invert the comparison and convert to LT and
     GE, respectively.  */
  switch (cmp_code)
    {
    case GT: cmp_code = LT; break;
    case LE: cmp_code = GE; break;
    case GTU: cmp_code = LTU; break;
    case LEU: cmp_code = GEU; break;
    default: break;
    }
  if (cmp_code == GET_CODE (operands[0]))
    {
      op0 = cmp_operands[0];
      op1 = cmp_operands[1];
    }
  else
    {
      op0 = cmp_operands[1];
      op1 = cmp_operands[0];
    }
  op0 = force_reg (mode, op0);
  if (!arith_operand (op1, mode))
    op1 = force_reg (mode, op1);

  emit_insn (gen_rtx_TRAP_IF (VOIDmode,
                              gen_rtx_fmt_ee (cmp_code, mode, op0, op1),
                              operands[1]));
}
\f
/* Argument support functions.  */

/* Initialize CUMULATIVE_ARGS for a function.  */

void
init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype,
                      rtx libname ATTRIBUTE_UNUSED)
{
  static CUMULATIVE_ARGS zero_cum;
  tree param, next_param;

  *cum = zero_cum;
  cum->prototype = (fntype && TYPE_ARG_TYPES (fntype));

  /* Determine if this function has variable arguments.  This is
     indicated by the last argument being 'void_type_mode' if there
     are no variable arguments.  The standard MIPS calling sequence
     passes all arguments in the general purpose registers in this case.  */

  for (param = fntype ? TYPE_ARG_TYPES (fntype) : 0;
       param != 0; param = next_param)
    {
      next_param = TREE_CHAIN (param);
      if (next_param == 0 && TREE_VALUE (param) != void_type_node)
        cum->gp_reg_found = 1;
    }
}


/* Fill INFO with information about a single argument.  CUM is the
   cumulative state for earlier arguments.  MODE is the mode of this
   argument and TYPE is its type (if known).  NAMED is true if this
   is a named (fixed) argument rather than a variable one.  */

static void
mips_arg_info (const CUMULATIVE_ARGS *cum, enum machine_mode mode,
               tree type, int named, struct mips_arg_info *info)
{
  bool doubleword_aligned_p;
  unsigned int num_bytes, num_words, max_regs;

  /* Work out the size of the argument.  */
  num_bytes = type ? int_size_in_bytes (type) : GET_MODE_SIZE (mode);
  num_words = (num_bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;

  /* Decide whether it should go in a floating-point register, assuming
     one is free.  Later code checks for availability.

     The checks against UNITS_PER_FPVALUE handle the soft-float and
     single-float cases.  */
  switch (mips_abi)
    {
    case ABI_EABI:
      /* The EABI conventions have traditionally been defined in terms
         of TYPE_MODE, regardless of the actual type.  */
      info->fpr_p = ((GET_MODE_CLASS (mode) == MODE_FLOAT
                      || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
                     && GET_MODE_SIZE (mode) <= UNITS_PER_FPVALUE);
      break;

    case ABI_32:
    case ABI_O64:
      /* Only leading floating-point scalars are passed in
         floating-point registers.  We also handle vector floats the same
         say, which is OK because they are not covered by the standard ABI.  */
      info->fpr_p = (!cum->gp_reg_found
                     && cum->arg_number < 2
                     && (type == 0 || SCALAR_FLOAT_TYPE_P (type)
                         || VECTOR_FLOAT_TYPE_P (type))
                     && (GET_MODE_CLASS (mode) == MODE_FLOAT
                         || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
                     && GET_MODE_SIZE (mode) <= UNITS_PER_FPVALUE);
      break;

    case ABI_N32:
    case ABI_64:
      /* Scalar and complex floating-point types are passed in
         floating-point registers.  */
      info->fpr_p = (named
                     && (type == 0 || FLOAT_TYPE_P (type))
                     && (GET_MODE_CLASS (mode) == MODE_FLOAT
                         || GET_MODE_CLASS (mode) == MODE_COMPLEX_FLOAT
                         || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
                     && GET_MODE_UNIT_SIZE (mode) <= UNITS_PER_FPVALUE);

      /* ??? According to the ABI documentation, the real and imaginary
         parts of complex floats should be passed in individual registers.
         The real and imaginary parts of stack arguments are supposed
         to be contiguous and there should be an extra word of padding
         at the end.

         This has two problems.  First, it makes it impossible to use a
         single "void *" va_list type, since register and stack arguments
         are passed differently.  (At the time of writing, MIPSpro cannot
         handle complex float varargs correctly.)  Second, it's unclear
         what should happen when there is only one register free.

         For now, we assume that named complex floats should go into FPRs
         if there are two FPRs free, otherwise they should be passed in the
         same way as a struct containing two floats.  */
      if (info->fpr_p
          && GET_MODE_CLASS (mode) == MODE_COMPLEX_FLOAT
          && GET_MODE_UNIT_SIZE (mode) < UNITS_PER_FPVALUE)
        {
          if (cum->num_gprs >= MAX_ARGS_IN_REGISTERS - 1)
            info->fpr_p = false;
          else
            num_words = 2;
        }
      break;

    default:
      gcc_unreachable ();
    }

  /* See whether the argument has doubleword alignment.  */
  doubleword_aligned_p = FUNCTION_ARG_BOUNDARY (mode, type) > BITS_PER_WORD;

  /* Set REG_OFFSET to the register count we're interested in.
     The EABI allocates the floating-point registers separately,
     but the other ABIs allocate them like integer registers.  */
  info->reg_offset = (mips_abi == ABI_EABI && info->fpr_p
                      ? cum->num_fprs
                      : cum->num_gprs);

  /* Advance to an even register if the argument is doubleword-aligned.  */
  if (doubleword_aligned_p)
    info->reg_offset += info->reg_offset & 1;

  /* Work out the offset of a stack argument.  */
  info->stack_offset = cum->stack_words;
  if (doubleword_aligned_p)
    info->stack_offset += info->stack_offset & 1;

  max_regs = MAX_ARGS_IN_REGISTERS - info->reg_offset;

  /* Partition the argument between registers and stack.  */
  info->reg_words = MIN (num_words, max_regs);
  info->stack_words = num_words - info->reg_words;
}

/* INFO describes an argument that is passed in a single-register value.
   Return the register it uses, assuming that FPRs are available if
   HARD_FLOAT_P.  */

static unsigned int
mips_arg_regno (const struct mips_arg_info *info, bool hard_float_p)
{
  if (!info->fpr_p || !hard_float_p)
    return GP_ARG_FIRST + info->reg_offset;
  else if (mips_abi == ABI_32 && TARGET_DOUBLE_FLOAT && info->reg_offset > 0)
    /* In o32, the second argument is always passed in $f14
       for TARGET_DOUBLE_FLOAT, regardless of whether the
       first argument was a word or doubleword.  */
    return FP_ARG_FIRST + 2;
  else
    return FP_ARG_FIRST + info->reg_offset;
}

static bool
mips_strict_argument_naming (CUMULATIVE_ARGS *ca ATTRIBUTE_UNUSED)
{
  return !TARGET_OLDABI;
}

/* Implement FUNCTION_ARG.  */

struct rtx_def *
function_arg (const CUMULATIVE_ARGS *cum, enum machine_mode mode,
              tree type, int named)
{
  struct mips_arg_info info;

  /* We will be called with a mode of VOIDmode after the last argument
     has been seen.  Whatever we return will be passed to the call
     insn.  If we need a mips16 fp_code, return a REG with the code
     stored as the mode.  */
  if (mode == VOIDmode)
    {
      if (TARGET_MIPS16 && cum->fp_code != 0)
        return gen_rtx_REG ((enum machine_mode) cum->fp_code, 0);

      else
        return 0;
    }

  mips_arg_info (cum, mode, type, named, &info);

  /* Return straight away if the whole argument is passed on the stack.  */
  if (info.reg_offset == MAX_ARGS_IN_REGISTERS)
    return 0;

  if (type != 0
      && TREE_CODE (type) == RECORD_TYPE
      && TARGET_NEWABI
      && TYPE_SIZE_UNIT (type)
      && host_integerp (TYPE_SIZE_UNIT (type), 1)
      && named)
    {
      /* The Irix 6 n32/n64 ABIs say that if any 64-bit chunk of the
         structure contains a double in its entirety, then that 64-bit
         chunk is passed in a floating point register.  */
      tree field;

      /* First check to see if there is any such field.  */
      for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
        if (TREE_CODE (field) == FIELD_DECL
            && TREE_CODE (TREE_TYPE (field)) == REAL_TYPE
            && TYPE_PRECISION (TREE_TYPE (field)) == BITS_PER_WORD
            && host_integerp (bit_position (field), 0)
            && int_bit_position (field) % BITS_PER_WORD == 0)
          break;

      if (field != 0)
        {
          /* Now handle the special case by returning a PARALLEL
             indicating where each 64-bit chunk goes.  INFO.REG_WORDS
             chunks are passed in registers.  */
          unsigned int i;
          HOST_WIDE_INT bitpos;
          rtx ret;

          /* assign_parms checks the mode of ENTRY_PARM, so we must
             use the actual mode here.  */
          ret = gen_rtx_PARALLEL (mode, rtvec_alloc (info.reg_words));

          bitpos = 0;
          field = TYPE_FIELDS (type);
          for (i = 0; i < info.reg_words; i++)
            {
              rtx reg;

              for (; field; field = TREE_CHAIN (field))
                if (TREE_CODE (field) == FIELD_DECL
                    && int_bit_position (field) >= bitpos)
                  break;

              if (field
                  && int_bit_position (field) == bitpos
                  && TREE_CODE (TREE_TYPE (field)) == REAL_TYPE
                  && !TARGET_SOFT_FLOAT
                  && TYPE_PRECISION (TREE_TYPE (field)) == BITS_PER_WORD)
                reg = gen_rtx_REG (DFmode, FP_ARG_FIRST + info.reg_offset + i);
              else
                reg = gen_rtx_REG (DImode, GP_ARG_FIRST + info.reg_offset + i);

              XVECEXP (ret, 0, i)
                = gen_rtx_EXPR_LIST (VOIDmode, reg,
                                     GEN_INT (bitpos / BITS_PER_UNIT));

              bitpos += BITS_PER_WORD;
            }
          return ret;
        }
    }

  /* Handle the n32/n64 conventions for passing complex floating-point
     arguments in FPR pairs.  The real part goes in the lower register
     and the imaginary part goes in the upper register.  */
  if (TARGET_NEWABI
      && info.fpr_p
      && GET_MODE_CLASS (mode) == MODE_COMPLEX_FLOAT)
    {
      rtx real, imag;
      enum machine_mode inner;
      int reg;

      inner = GET_MODE_INNER (mode);
      reg = FP_ARG_FIRST + info.reg_offset;
      if (info.reg_words * UNITS_PER_WORD == GET_MODE_SIZE (inner))
        {
          /* Real part in registers, imaginary part on stack.  */
          gcc_assert (info.stack_words == info.reg_words);
          return gen_rtx_REG (inner, reg);
        }
      else
        {
          gcc_assert (info.stack_words == 0);
          real = gen_rtx_EXPR_LIST (VOIDmode,
                                    gen_rtx_REG (inner, reg),
                                    const0_rtx);
          imag = gen_rtx_EXPR_LIST (VOIDmode,
                                    gen_rtx_REG (inner,
                                                 reg + info.reg_words / 2),
                                    GEN_INT (GET_MODE_SIZE (inner)));
          return gen_rtx_PARALLEL (mode, gen_rtvec (2, real, imag));
        }
    }

  return gen_rtx_REG (mode, mips_arg_regno (&info, TARGET_HARD_FLOAT));
}

/* Implement FUNCTION_ARG_ADVANCE.  */

void
function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode,
                      tree type, int named)
{
  struct mips_arg_info info;

  mips_arg_info (cum, mode, type, named, &info);

  if (!info.fpr_p)
    cum->gp_reg_found = true;

  /* See the comment above the cumulative args structure in mips.h
     for an explanation of what this code does.  It assumes the O32
     ABI, which passes at most 2 arguments in float registers.  */
  if (cum->arg_number < 2 && info.fpr_p)
    cum->fp_code += (mode == SFmode ? 1 : 2) << (cum->arg_number * 2);

  if (mips_abi != ABI_EABI || !info.fpr_p)
    cum->num_gprs = info.reg_offset + info.reg_words;
  else if (info.reg_words > 0)
    cum->num_fprs += MAX_FPRS_PER_FMT;

  if (info.stack_words > 0)
    cum->stack_words = info.stack_offset + info.stack_words;

  cum->arg_number++;
}

/* Implement TARGET_ARG_PARTIAL_BYTES.  */

static int
mips_arg_partial_bytes (CUMULATIVE_ARGS *cum,
                        enum machine_mode mode, tree type, bool named)
{
  struct mips_arg_info info;

  mips_arg_info (cum, mode, type, named, &info);
  return info.stack_words > 0 ? info.reg_words * UNITS_PER_WORD : 0;
}


/* Implement FUNCTION_ARG_BOUNDARY.  Every parameter gets at least
   PARM_BOUNDARY bits of alignment, but will be given anything up
   to STACK_BOUNDARY bits if the type requires it.  */

int
function_arg_boundary (enum machine_mode mode, tree type)
{
  unsigned int alignment;

  alignment = type ? TYPE_ALIGN (type) : GET_MODE_ALIGNMENT (mode);
  if (alignment < PARM_BOUNDARY)
    alignment = PARM_BOUNDARY;
  if (alignment > STACK_BOUNDARY)
    alignment = STACK_BOUNDARY;
  return alignment;
}

/* Return true if FUNCTION_ARG_PADDING (MODE, TYPE) should return
   upward rather than downward.  In other words, return true if the
   first byte of the stack slot has useful data, false if the last
   byte does.  */

bool
mips_pad_arg_upward (enum machine_mode mode, const_tree type)
{
  /* On little-endian targets, the first byte of every stack argument
     is passed in the first byte of the stack slot.  */
  if (!BYTES_BIG_ENDIAN)
    return true;

  /* Otherwise, integral types are padded downward: the last byte of a
     stack argument is passed in the last byte of the stack slot.  */
  if (type != 0
      ? (INTEGRAL_TYPE_P (type)
         || POINTER_TYPE_P (type)
         || FIXED_POINT_TYPE_P (type))
      : (GET_MODE_CLASS (mode) == MODE_INT
         || ALL_SCALAR_FIXED_POINT_MODE_P (mode)))
    return false;

  /* Big-endian o64 pads floating-point arguments downward.  */
  if (mips_abi == ABI_O64)
    if (type != 0 ? FLOAT_TYPE_P (type) : GET_MODE_CLASS (mode) == MODE_FLOAT)
      return false;

  /* Other types are padded upward for o32, o64, n32 and n64.  */
  if (mips_abi != ABI_EABI)
    return true;

  /* Arguments smaller than a stack slot are padded downward.  */
  if (mode != BLKmode)
    return (GET_MODE_BITSIZE (mode) >= PARM_BOUNDARY);
  else
    return (int_size_in_bytes (type) >= (PARM_BOUNDARY / BITS_PER_UNIT));
}


/* Likewise BLOCK_REG_PADDING (MODE, TYPE, ...).  Return !BYTES_BIG_ENDIAN
   if the least significant byte of the register has useful data.  Return
   the opposite if the most significant byte does.  */

bool
mips_pad_reg_upward (enum machine_mode mode, tree type)
{
  /* No shifting is required for floating-point arguments.  */
  if (type != 0 ? FLOAT_TYPE_P (type) : GET_MODE_CLASS (mode) == MODE_FLOAT)
    return !BYTES_BIG_ENDIAN;

  /* Otherwise, apply the same padding to register arguments as we do
     to stack arguments.  */
  return mips_pad_arg_upward (mode, type);
}


/* Return nonzero when an argument must be passed by reference.  */

static bool
mips_pass_by_reference (CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED,
                        enum machine_mode mode, const_tree type,
                        bool named ATTRIBUTE_UNUSED)
{
  if (mips_abi == ABI_EABI)
    {
      int size;

      /* ??? How should SCmode be handled?  */
      if (mode == DImode || mode == DFmode
          || mode == DQmode || mode == UDQmode
          || mode == DAmode || mode == UDAmode)
        return 0;

      size = type ? int_size_in_bytes (type) : GET_MODE_SIZE (mode);
      return size == -1 || size > UNITS_PER_WORD;
    }
  else
    {
      /* If we have a variable-sized parameter, we have no choice.  */
      return targetm.calls.must_pass_in_stack (mode, type);
    }
}

static bool
mips_callee_copies (CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED,
                    enum machine_mode mode ATTRIBUTE_UNUSED,
                    const_tree type ATTRIBUTE_UNUSED, bool named)
{
  return mips_abi == ABI_EABI && named;
}
\f
/* See whether VALTYPE is a record whose fields should be returned in
   floating-point registers.  If so, return the number of fields and
   list them in FIELDS (which should have two elements).  Return 0
   otherwise.

   For n32 & n64, a structure with one or two fields is returned in
   floating-point registers as long as every field has a floating-point
   type.  */

static int
mips_fpr_return_fields (const_tree valtype, tree *fields)
{
  tree field;
  int i;

  if (!TARGET_NEWABI)
    return 0;

  if (TREE_CODE (valtype) != RECORD_TYPE)
    return 0;

  i = 0;
  for (field = TYPE_FIELDS (valtype); field != 0; field = TREE_CHAIN (field))
    {
      if (TREE_CODE (field) != FIELD_DECL)
        continue;

      if (TREE_CODE (TREE_TYPE (field)) != REAL_TYPE)
        return 0;

      if (i == 2)
        return 0;

      fields[i++] = field;
    }
  return i;
}


/* Implement TARGET_RETURN_IN_MSB.  For n32 & n64, we should return
   a value in the most significant part of $2/$3 if:

      - the target is big-endian;

      - the value has a structure or union type (we generalize this to
        cover aggregates from other languages too); and

      - the structure is not returned in floating-point registers.  */

static bool
mips_return_in_msb (const_tree valtype)
{
  tree fields[2];

  return (TARGET_NEWABI
          && TARGET_BIG_ENDIAN
          && AGGREGATE_TYPE_P (valtype)
          && mips_fpr_return_fields (valtype, fields) == 0);
}


/* Return true if the function return value MODE will get returned in a
   floating-point register.  */

static bool
mips_return_mode_in_fpr_p (enum machine_mode mode)
{
  return ((GET_MODE_CLASS (mode) == MODE_FLOAT
           || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT
           || GET_MODE_CLASS (mode) == MODE_COMPLEX_FLOAT)
          && GET_MODE_UNIT_SIZE (mode) <= UNITS_PER_HWFPVALUE);
}

/* Return a composite value in a pair of floating-point registers.
   MODE1 and OFFSET1 are the mode and byte offset for the first value,
   likewise MODE2 and OFFSET2 for the second.  MODE is the mode of the
   complete value.

   For n32 & n64, $f0 always holds the first value and $f2 the second.
   Otherwise the values are packed together as closely as possible.  */

static rtx
mips_return_fpr_pair (enum machine_mode mode,
                      enum machine_mode mode1, HOST_WIDE_INT offset1,
                      enum machine_mode mode2, HOST_WIDE_INT offset2)
{
  int inc;

  inc = (TARGET_NEWABI ? 2 : MAX_FPRS_PER_FMT);
  return gen_rtx_PARALLEL
    (mode,
     gen_rtvec (2,
                gen_rtx_EXPR_LIST (VOIDmode,
                                   gen_rtx_REG (mode1, FP_RETURN),
                                   GEN_INT (offset1)),
                gen_rtx_EXPR_LIST (VOIDmode,
                                   gen_rtx_REG (mode2, FP_RETURN + inc),
                                   GEN_INT (offset2))));

}


/* Implement FUNCTION_VALUE and LIBCALL_VALUE.  For normal calls,
   VALTYPE is the return type and MODE is VOIDmode.  For libcalls,
   VALTYPE is null and MODE is the mode of the return value.  */

rtx
mips_function_value (const_tree valtype, const_tree func ATTRIBUTE_UNUSED,
                     enum machine_mode mode)
{
  if (valtype)
    {
      tree fields[2];
      int unsignedp;

      mode = TYPE_MODE (valtype);
      unsignedp = TYPE_UNSIGNED (valtype);

      /* Since we define TARGET_PROMOTE_FUNCTION_RETURN that returns
         true, we must promote the mode just as PROMOTE_MODE does.  */
      mode = promote_mode (valtype, mode, &unsignedp, 1);

      /* Handle structures whose fields are returned in $f0/$f2.  */
      switch (mips_fpr_return_fields (valtype, fields))
        {
        case 1:
          return gen_rtx_REG (mode, FP_RETURN);

        case 2:
          return mips_return_fpr_pair (mode,
                                       TYPE_MODE (TREE_TYPE (fields[0])),
                                       int_byte_position (fields[0]),
                                       TYPE_MODE (TREE_TYPE (fields[1])),
                                       int_byte_position (fields[1]));
        }

      /* If a value is passed in the most significant part of a register, see
         whether we have to round the mode up to a whole number of words.  */
      if (mips_return_in_msb (valtype))
        {
          HOST_WIDE_INT size = int_size_in_bytes (valtype);
          if (size % UNITS_PER_WORD != 0)
            {
              size += UNITS_PER_WORD - size % UNITS_PER_WORD;
              mode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
            }
        }

      /* For EABI, the class of return register depends entirely on MODE.
         For example, "struct { some_type x; }" and "union { some_type x; }"
         are returned in the same way as a bare "some_type" would be.
         Other ABIs only use FPRs for scalar, complex or vector types.  */
      if (mips_abi != ABI_EABI && !FLOAT_TYPE_P (valtype))
        return gen_rtx_REG (mode, GP_RETURN);
    }

  if (!TARGET_MIPS16)
    {
      /* Handle long doubles for n32 & n64.  */
      if (mode == TFmode)
        return mips_return_fpr_pair (mode,
                                     DImode, 0,
                                     DImode, GET_MODE_SIZE (mode) / 2);

      if (mips_return_mode_in_fpr_p (mode))
        {
          if (GET_MODE_CLASS (mode) == MODE_COMPLEX_FLOAT)
            return mips_return_fpr_pair (mode,
                                         GET_MODE_INNER (mode), 0,
                                         GET_MODE_INNER (mode),
                                         GET_MODE_SIZE (mode) / 2);
          else
            return gen_rtx_REG (mode, FP_RETURN);
        }
    }

  return gen_rtx_REG (mode, GP_RETURN);
}

/* Implement TARGET_RETURN_IN_MEMORY.  Under the old (i.e., 32 and O64 ABIs)
   all BLKmode objects are returned in memory.  Under the new (N32 and
   64-bit MIPS ABIs) small structures are returned in a register.
   Objects with varying size must still be returned in memory, of
   course.  */

static bool
mips_return_in_memory (const_tree type, const_tree fndecl ATTRIBUTE_UNUSED)
{
  if (TARGET_OLDABI)
    return (TYPE_MODE (type) == BLKmode);
  else
    return ((int_size_in_bytes (type) > (2 * UNITS_PER_WORD))
            || (int_size_in_bytes (type) == -1));
}
\f
static void
mips_setup_incoming_varargs (CUMULATIVE_ARGS *cum, enum machine_mode mode,
                             tree type, int *pretend_size ATTRIBUTE_UNUSED,
                             int no_rtl)
{
  CUMULATIVE_ARGS local_cum;
  int gp_saved, fp_saved;

  /* The caller has advanced CUM up to, but not beyond, the last named
     argument.  Advance a local copy of CUM past the last "real" named
     argument, to find out how many registers are left over.  */

  local_cum = *cum;
  FUNCTION_ARG_ADVANCE (local_cum, mode, type, 1);

  /* Found out how many registers we need to save.  */
  gp_saved = MAX_ARGS_IN_REGISTERS - local_cum.num_gprs;
  fp_saved = (EABI_FLOAT_VARARGS_P
              ? MAX_ARGS_IN_REGISTERS - local_cum.num_fprs
              : 0);

  if (!no_rtl)
    {
      if (gp_saved > 0)
        {
          rtx ptr, mem;

          ptr = plus_constant (virtual_incoming_args_rtx,
                               REG_PARM_STACK_SPACE (cfun->decl)
                               - gp_saved * UNITS_PER_WORD);
          mem = gen_rtx_MEM (BLKmode, ptr);
          set_mem_alias_set (mem, get_varargs_alias_set ());

          move_block_from_reg (local_cum.num_gprs + GP_ARG_FIRST,
                               mem, gp_saved);
        }
      if (fp_saved > 0)
        {
          /* We can't use move_block_from_reg, because it will use
             the wrong mode.  */
          enum machine_mode mode;
          int off, i;

          /* Set OFF to the offset from virtual_incoming_args_rtx of
             the first float register.  The FP save area lies below
             the integer one, and is aligned to UNITS_PER_FPVALUE bytes.  */
          off = -gp_saved * UNITS_PER_WORD;
          off &= ~(UNITS_PER_FPVALUE - 1);
          off -= fp_saved * UNITS_PER_FPREG;

          mode = TARGET_SINGLE_FLOAT ? SFmode : DFmode;

          for (i = local_cum.num_fprs; i < MAX_ARGS_IN_REGISTERS;
               i += MAX_FPRS_PER_FMT)
            {
              rtx ptr, mem;

              ptr = plus_constant (virtual_incoming_args_rtx, off);
              mem = gen_rtx_MEM (mode, ptr);
              set_mem_alias_set (mem, get_varargs_alias_set ());
              mips_emit_move (mem, gen_rtx_REG (mode, FP_ARG_FIRST + i));
              off += UNITS_PER_HWFPVALUE;
            }
        }
    }
  if (REG_PARM_STACK_SPACE (cfun->decl) == 0)
    cfun->machine->varargs_size = (gp_saved * UNITS_PER_WORD
                                   + fp_saved * UNITS_PER_FPREG);
}

/* Create the va_list data type.
   We keep 3 pointers, and two offsets.
   Two pointers are to the overflow area, which starts at the CFA.
     One of these is constant, for addressing into the GPR save area below it.
     The other is advanced up the stack through the overflow region.
   The third pointer is to the GPR save area.  Since the FPR save area
     is just below it, we can address FPR slots off this pointer.
   We also keep two one-byte offsets, which are to be subtracted from the
     constant pointers to yield addresses in the GPR and FPR save areas.
     These are downcounted as float or non-float arguments are used,
     and when they get to zero, the argument must be obtained from the
     overflow region.
   If !EABI_FLOAT_VARARGS_P, then no FPR save area exists, and a single
     pointer is enough.  It's started at the GPR save area, and is
     advanced, period.
   Note that the GPR save area is not constant size, due to optimization
     in the prologue.  Hence, we can't use a design with two pointers
     and two offsets, although we could have designed this with two pointers
     and three offsets.  */

static tree
mips_build_builtin_va_list (void)
{
  if (EABI_FLOAT_VARARGS_P)
    {
      tree f_ovfl, f_gtop, f_ftop, f_goff, f_foff, f_res, record;
      tree array, index;

      record = (*lang_hooks.types.make_type) (RECORD_TYPE);

      f_ovfl = build_decl (FIELD_DECL, get_identifier ("__overflow_argptr"),
                          ptr_type_node);
      f_gtop = build_decl (FIELD_DECL, get_identifier ("__gpr_top"),
                          ptr_type_node);
      f_ftop = build_decl (FIELD_DECL, get_identifier ("__fpr_top"),
                          ptr_type_node);
      f_goff = build_decl (FIELD_DECL, get_identifier ("__gpr_offset"),
                          unsigned_char_type_node);
      f_foff = build_decl (FIELD_DECL, get_identifier ("__fpr_offset"),
                          unsigned_char_type_node);
      /* Explicitly pad to the size of a pointer, so that -Wpadded won't
         warn on every user file.  */
      index = build_int_cst (NULL_TREE, GET_MODE_SIZE (ptr_mode) - 2 - 1);
      array = build_array_type (unsigned_char_type_node,
                                build_index_type (index));
      f_res = build_decl (FIELD_DECL, get_identifier ("__reserved"), array);

      DECL_FIELD_CONTEXT (f_ovfl) = record;
      DECL_FIELD_CONTEXT (f_gtop) = record;
      DECL_FIELD_CONTEXT (f_ftop) = record;
      DECL_FIELD_CONTEXT (f_goff) = record;
      DECL_FIELD_CONTEXT (f_foff) = record;
      DECL_FIELD_CONTEXT (f_res) = record;

      TYPE_FIELDS (record) = f_ovfl;
      TREE_CHAIN (f_ovfl) = f_gtop;
      TREE_CHAIN (f_gtop) = f_ftop;
      TREE_CHAIN (f_ftop) = f_goff;
      TREE_CHAIN (f_goff) = f_foff;
      TREE_CHAIN (f_foff) = f_res;

      layout_type (record);
      return record;
    }
  else if (TARGET_IRIX && TARGET_IRIX6)
    /* On IRIX 6, this type is 'char *'.  */
    return build_pointer_type (char_type_node);
  else
    /* Otherwise, we use 'void *'.  */
    return ptr_type_node;
}

/* Implement va_start.  */

void
mips_va_start (tree valist, rtx nextarg)
{
  if (EABI_FLOAT_VARARGS_P)
    {
      const CUMULATIVE_ARGS *cum;
      tree f_ovfl, f_gtop, f_ftop, f_goff, f_foff;
      tree ovfl, gtop, ftop, goff, foff;
      tree t;
      int gpr_save_area_size;
      int fpr_save_area_size;
      int fpr_offset;

      cum = &current_function_args_info;
      gpr_save_area_size
        = (MAX_ARGS_IN_REGISTERS - cum->num_gprs) * UNITS_PER_WORD;
      fpr_save_area_size
        = (MAX_ARGS_IN_REGISTERS - cum->num_fprs) * UNITS_PER_FPREG;

      f_ovfl = TYPE_FIELDS (va_list_type_node);
      f_gtop = TREE_CHAIN (f_ovfl);
      f_ftop = TREE_CHAIN (f_gtop);
      f_goff = TREE_CHAIN (f_ftop);
      f_foff = TREE_CHAIN (f_goff);

      ovfl = build3 (COMPONENT_REF, TREE_TYPE (f_ovfl), valist, f_ovfl,
                     NULL_TREE);
      gtop = build3 (COMPONENT_REF, TREE_TYPE (f_gtop), valist, f_gtop,
                     NULL_TREE);
      ftop = build3 (COMPONENT_REF, TREE_TYPE (f_ftop), valist, f_ftop,
                     NULL_TREE);
      goff = build3 (COMPONENT_REF, TREE_TYPE (f_goff), valist, f_goff,
                     NULL_TREE);
      foff = build3 (COMPONENT_REF, TREE_TYPE (f_foff), valist, f_foff,
                     NULL_TREE);

      /* Emit code to initialize OVFL, which points to the next varargs
         stack argument.  CUM->STACK_WORDS gives the number of stack
         words used by named arguments.  */
      t = make_tree (TREE_TYPE (ovfl), virtual_incoming_args_rtx);
      if (cum->stack_words > 0)
        t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (ovfl), t,
                    size_int (cum->stack_words * UNITS_PER_WORD));
      t = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (ovfl), ovfl, t);
      expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);

      /* Emit code to initialize GTOP, the top of the GPR save area.  */
      t = make_tree (TREE_TYPE (gtop), virtual_incoming_args_rtx);
      t = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (gtop), gtop, t);
      expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);

      /* Emit code to initialize FTOP, the top of the FPR save area.
         This address is gpr_save_area_bytes below GTOP, rounded
         down to the next fp-aligned boundary.  */
      t = make_tree (TREE_TYPE (ftop), virtual_incoming_args_rtx);
      fpr_offset = gpr_save_area_size + UNITS_PER_FPVALUE - 1;
      fpr_offset &= ~(UNITS_PER_FPVALUE - 1);
      if (fpr_offset)
        t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (ftop), t,
                    size_int (-fpr_offset));
      t = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (ftop), ftop, t);
      expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);

      /* Emit code to initialize GOFF, the offset from GTOP of the
         next GPR argument.  */
      t = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (goff), goff,
                  build_int_cst (NULL_TREE, gpr_save_area_size));
      expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);

      /* Likewise emit code to initialize FOFF, the offset from FTOP
         of the next FPR argument.  */
      t = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (foff), foff,
                  build_int_cst (NULL_TREE, fpr_save_area_size));
      expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
    }
  else
    {
      nextarg = plus_constant (nextarg, -cfun->machine->varargs_size);
      std_expand_builtin_va_start (valist, nextarg);
    }
}
\f
/* Implement va_arg.  */

static tree
mips_gimplify_va_arg_expr (tree valist, tree type, tree *pre_p, tree *post_p)
{
  HOST_WIDE_INT size, rsize;
  tree addr;
  bool indirect;

  indirect = pass_by_reference (NULL, TYPE_MODE (type), type, 0);

  if (indirect)
    type = build_pointer_type (type);

  size = int_size_in_bytes (type);
  rsize = (size + UNITS_PER_WORD - 1) & -UNITS_PER_WORD;

  if (mips_abi != ABI_EABI || !EABI_FLOAT_VARARGS_P)
    addr = std_gimplify_va_arg_expr (valist, type, pre_p, post_p);
  else
    {
      /* Not a simple merged stack.      */

      tree f_ovfl, f_gtop, f_ftop, f_goff, f_foff;
      tree ovfl, top, off, align;
      HOST_WIDE_INT osize;
      tree t, u;

      f_ovfl = TYPE_FIELDS (va_list_type_node);
      f_gtop = TREE_CHAIN (f_ovfl);
      f_ftop = TREE_CHAIN (f_gtop);
      f_goff = TREE_CHAIN (f_ftop);
      f_foff = TREE_CHAIN (f_goff);

      /* We maintain separate pointers and offsets for floating-point
         and integer arguments, but we need similar code in both cases.
         Let:

         TOP be the top of the register save area;
         OFF be the offset from TOP of the next register;
         ADDR_RTX be the address of the argument;
         RSIZE be the number of bytes used to store the argument
         when it's in the register save area;
         OSIZE be the number of bytes used to store it when it's
         in the stack overflow area; and
         PADDING be (BYTES_BIG_ENDIAN ? OSIZE - RSIZE : 0)

         The code we want is:

         1: off &= -rsize;        // round down
         2: if (off != 0)
         3:   {
         4:      addr_rtx = top - off;
         5:      off -= rsize;
         6:   }
         7: else
         8:   {
         9:      ovfl += ((intptr_t) ovfl + osize - 1) & -osize;
         10:     addr_rtx = ovfl + PADDING;
         11:     ovfl += osize;
         14:   }

         [1] and [9] can sometimes be optimized away.  */

      ovfl = build3 (COMPONENT_REF, TREE_TYPE (f_ovfl), valist, f_ovfl,
                     NULL_TREE);

      if (GET_MODE_CLASS (TYPE_MODE (type)) == MODE_FLOAT
          && GET_MODE_SIZE (TYPE_MODE (type)) <= UNITS_PER_FPVALUE)
        {
          top = build3 (COMPONENT_REF, TREE_TYPE (f_ftop), valist, f_ftop,
                        NULL_TREE);
          off = build3 (COMPONENT_REF, TREE_TYPE (f_foff), valist, f_foff,
                        NULL_TREE);

          /* When floating-point registers are saved to the stack,
             each one will take up UNITS_PER_HWFPVALUE bytes, regardless
             of the float's precision.  */
          rsize = UNITS_PER_HWFPVALUE;

          /* Overflow arguments are padded to UNITS_PER_WORD bytes
             (= PARM_BOUNDARY bits).  This can be different from RSIZE
             in two cases:

             (1) On 32-bit targets when TYPE is a structure such as:

             struct s { float f; };

             Such structures are passed in paired FPRs, so RSIZE
             will be 8 bytes.  However, the structure only takes
             up 4 bytes of memory, so OSIZE will only be 4.

             (2) In combinations such as -mgp64 -msingle-float
             -fshort-double.  Doubles passed in registers
             will then take up 4 (UNITS_PER_HWFPVALUE) bytes,
             but those passed on the stack take up
             UNITS_PER_WORD bytes.  */
          osize = MAX (GET_MODE_SIZE (TYPE_MODE (type)), UNITS_PER_WORD);
        }
      else
        {
          top = build3 (COMPONENT_REF, TREE_TYPE (f_gtop), valist, f_gtop,
                        NULL_TREE);
          off = build3 (COMPONENT_REF, TREE_TYPE (f_goff), valist, f_goff,
                        NULL_TREE);
          if (rsize > UNITS_PER_WORD)
            {
              /* [1] Emit code for: off &= -rsize.      */
              t = build2 (BIT_AND_EXPR, TREE_TYPE (off), off,
                          build_int_cst (NULL_TREE, -rsize));
              t = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (off), off, t);
              gimplify_and_add (t, pre_p);
            }
          osize = rsize;
        }

      /* [2] Emit code to branch if off == 0.  */
      t = build2 (NE_EXPR, boolean_type_node, off,
                  build_int_cst (TREE_TYPE (off), 0));
      addr = build3 (COND_EXPR, ptr_type_node, t, NULL_TREE, NULL_TREE);

      /* [5] Emit code for: off -= rsize.  We do this as a form of
         post-increment not available to C.  Also widen for the
         coming pointer arithmetic.  */
      t = fold_convert (TREE_TYPE (off), build_int_cst (NULL_TREE, rsize));
      t = build2 (POSTDECREMENT_EXPR, TREE_TYPE (off), off, t);
      t = fold_convert (sizetype, t);
      t = fold_build1 (NEGATE_EXPR, sizetype, t);

      /* [4] Emit code for: addr_rtx = top - off.  On big endian machines,
         the argument has RSIZE - SIZE bytes of leading padding.  */
      t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (top), top, t);
      if (BYTES_BIG_ENDIAN && rsize > size)
        {
          u = size_int (rsize - size);
          t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (t), t, u);
        }
      COND_EXPR_THEN (addr) = t;

      if (osize > UNITS_PER_WORD)
        {
          /* [9] Emit: ovfl += ((intptr_t) ovfl + osize - 1) & -osize.  */
          u = size_int (osize - 1);
          t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (ovfl), ovfl, u);
          t = fold_convert (sizetype, t);
          u = size_int (-osize);
          t = build2 (BIT_AND_EXPR, sizetype, t, u);
          t = fold_convert (TREE_TYPE (ovfl), t);
          align = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (ovfl), ovfl, t);
        }
      else
        align = NULL;

      /* [10, 11].      Emit code to store ovfl in addr_rtx, then
         post-increment ovfl by osize.  On big-endian machines,
         the argument has OSIZE - SIZE bytes of leading padding.  */
      u = fold_convert (TREE_TYPE (ovfl),
                        build_int_cst (NULL_TREE, osize));
      t = build2 (POSTINCREMENT_EXPR, TREE_TYPE (ovfl), ovfl, u);
      if (BYTES_BIG_ENDIAN && osize > size)
        {
          u = size_int (osize - size);
          t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (t), t, u);
        }

      /* String [9] and [10,11] together.  */
      if (align)
        t = build2 (COMPOUND_EXPR, TREE_TYPE (t), align, t);
      COND_EXPR_ELSE (addr) = t;

      addr = fold_convert (build_pointer_type (type), addr);
      addr = build_va_arg_indirect_ref (addr);
    }

  if (indirect)
    addr = build_va_arg_indirect_ref (addr);

  return addr;
}
\f
/* We keep a list of functions for which we have already built stubs
   in build_mips16_call_stub.  */

struct mips16_stub
{
  struct mips16_stub *next;
  char *name;
  int fpret;
};

static struct mips16_stub *mips16_stubs;

/* Return a two-character string representing a function floating-point
   return mode, used to name MIPS16 function stubs.  */

static const char *
mips16_call_stub_mode_suffix (enum machine_mode mode)
{
  if (mode == SFmode)
    return "sf";
  else if (mode == DFmode)
    return "df";
  else if (mode == SCmode)
    return "sc";
  else if (mode == DCmode)
    return "dc";
  else if (mode == V2SFmode)
    return "df";
  else
    gcc_unreachable ();
}

/* Write out code to move floating point arguments in or out of
   general registers.  Output the instructions to FILE.  FP_CODE is
   the code describing which arguments are present (see the comment at
   the definition of CUMULATIVE_ARGS in mips.h).  FROM_FP_P is nonzero if
   we are copying from the floating point registers.  */

static void
mips16_fp_args (FILE *file, int fp_code, int from_fp_p)
{
  const char *s;
  int gparg, fparg;
  unsigned int f;
  CUMULATIVE_ARGS cum;

  /* This code only works for the original 32-bit ABI and the O64 ABI.  */
  gcc_assert (TARGET_OLDABI);

  if (from_fp_p)
    s = "mfc1";
  else
    s = "mtc1";

  init_cumulative_args (&cum, NULL, NULL);

  for (f = (unsigned int) fp_code; f != 0; f >>= 2)
    {
      enum machine_mode mode;
      struct mips_arg_info info;

      if ((f & 3) == 1)
        mode = SFmode;
      else if ((f & 3) == 2)
        mode = DFmode;
      else
        gcc_unreachable ();

      mips_arg_info (&cum, mode, NULL, true, &info);
      gparg = mips_arg_regno (&info, false);
      fparg = mips_arg_regno (&info, true);

      if (mode == SFmode)
        fprintf (file, "\t%s\t%s,%s\n", s,
                 reg_names[gparg], reg_names[fparg]);
      else if (TARGET_64BIT)
        fprintf (file, "\td%s\t%s,%s\n", s,
                 reg_names[gparg], reg_names[fparg]);
      else if (ISA_HAS_MXHC1)
        /* -mips32r2 -mfp64 */
        fprintf (file, "\t%s\t%s,%s\n\t%s\t%s,%s\n",
                 s,
                 reg_names[gparg + (WORDS_BIG_ENDIAN ? 1 : 0)],
                 reg_names[fparg],
                 from_fp_p ? "mfhc1" : "mthc1",
                 reg_names[gparg + (WORDS_BIG_ENDIAN ? 0 : 1)],
                 reg_names[fparg]);
      else if (TARGET_BIG_ENDIAN)
        fprintf (file, "\t%s\t%s,%s\n\t%s\t%s,%s\n", s,
                 reg_names[gparg], reg_names[fparg + 1], s,
                 reg_names[gparg + 1], reg_names[fparg]);
      else
        fprintf (file, "\t%s\t%s,%s\n\t%s\t%s,%s\n", s,
                 reg_names[gparg], reg_names[fparg], s,
                 reg_names[gparg + 1], reg_names[fparg + 1]);

      function_arg_advance (&cum, mode, NULL, true);
    }
}

/* Build a mips16 function stub.  This is used for functions which
   take arguments in the floating point registers.  It is 32-bit code
   that moves the floating point args into the general registers, and
   then jumps to the 16-bit code.  */

static void
build_mips16_function_stub (FILE *file)
{
  const char *fnname;
  char *secname, *stubname;
  tree stubid, stubdecl;
  int need_comma;
  unsigned int f;

  fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
  fnname = targetm.strip_name_encoding (fnname);
  secname = (char *) alloca (strlen (fnname) + 20);
  sprintf (secname, ".mips16.fn.%s", fnname);
  stubname = (char *) alloca (strlen (fnname) + 20);
  sprintf (stubname, "__fn_stub_%s", fnname);
  stubid = get_identifier (stubname);
  stubdecl = build_decl (FUNCTION_DECL, stubid,
                         build_function_type (void_type_node, NULL_TREE));
  DECL_SECTION_NAME (stubdecl) = build_string (strlen (secname), secname);
  DECL_RESULT (stubdecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);

  fprintf (file, "\t# Stub function for %s (", current_function_name ());
  need_comma = 0;
  for (f = (unsigned int) current_function_args_info.fp_code; f != 0; f >>= 2)
    {
      fprintf (file, "%s%s",
               need_comma ? ", " : "",
               (f & 3) == 1 ? "float" : "double");
      need_comma = 1;
    }
  fprintf (file, ")\n");

  fprintf (file, "\t.set\tnomips16\n");
  switch_to_section (function_section (stubdecl));
  ASM_OUTPUT_ALIGN (file, floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT));

  /* ??? If FUNCTION_NAME_ALREADY_DECLARED is defined, then we are
     within a .ent, and we cannot emit another .ent.  */
  if (!FUNCTION_NAME_ALREADY_DECLARED)
    {
      fputs ("\t.ent\t", file);
      assemble_name (file, stubname);
      fputs ("\n", file);
    }

  assemble_name (file, stubname);
  fputs (":\n", file);

  /* We don't want the assembler to insert any nops here.  */
  fprintf (file, "\t.set\tnoreorder\n");

  mips16_fp_args (file, current_function_args_info.fp_code, 1);

  fprintf (asm_out_file, "\t.set\tnoat\n");
  fprintf (asm_out_file, "\tla\t%s,", reg_names[GP_REG_FIRST + 1]);
  assemble_name (file, fnname);
  fprintf (file, "\n");
  fprintf (asm_out_file, "\tjr\t%s\n", reg_names[GP_REG_FIRST + 1]);
  fprintf (asm_out_file, "\t.set\tat\n");

  /* Unfortunately, we can't fill the jump delay slot.  We can't fill
     with one of the mfc1 instructions, because the result is not
     available for one instruction, so if the very first instruction
     in the function refers to the register, it will see the wrong
     value.  */
  fprintf (file, "\tnop\n");

  fprintf (file, "\t.set\treorder\n");

  if (!FUNCTION_NAME_ALREADY_DECLARED)
    {
      fputs ("\t.end\t", file);
      assemble_name (file, stubname);
      fputs ("\n", file);
    }

  switch_to_section (function_section (current_function_decl));
}

/* Emit code to return a double value from a mips16 stub.  GPREG is the
   first GP reg to use, FPREG is the first FP reg to use.  */

static void
mips16_fpret_double (int gpreg, int fpreg)
{
  if (TARGET_64BIT)
    fprintf (asm_out_file, "\tdmfc1\t%s,%s\n",
             reg_names[gpreg], reg_names[fpreg]);
  else if (TARGET_FLOAT64)
    {
      fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
               reg_names[gpreg + WORDS_BIG_ENDIAN],
               reg_names[fpreg]);
      fprintf (asm_out_file, "\tmfhc1\t%s,%s\n",
               reg_names[gpreg + !WORDS_BIG_ENDIAN],
               reg_names[fpreg]);
    }
  else
    {
      if (TARGET_BIG_ENDIAN)
        {
          fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                   reg_names[gpreg + 0],
                   reg_names[fpreg + 1]);
          fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                   reg_names[gpreg + 1],
                   reg_names[fpreg + 0]);
        }
      else
        {
          fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                   reg_names[gpreg + 0],
                   reg_names[fpreg + 0]);
          fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                   reg_names[gpreg + 1],
                   reg_names[fpreg + 1]);
        }
    }
}

/* Build a call stub for a mips16 call.  A stub is needed if we are
   passing any floating point values which should go into the floating
   point registers.  If we are, and the call turns out to be to a
   32-bit function, the stub will be used to move the values into the
   floating point registers before calling the 32-bit function.  The
   linker will magically adjust the function call to either the 16-bit
   function or the 32-bit stub, depending upon where the function call
   is actually defined.

   Similarly, we need a stub if the return value might come back in a
   floating point register.

   RETVAL is the location of the return value, or null if this is
   a call rather than a call_value.  FN is the address of the
   function and ARG_SIZE is the size of the arguments.  FP_CODE
   is the code built by function_arg.  This function returns a nonzero
   value if it builds the call instruction itself.  */

int
build_mips16_call_stub (rtx retval, rtx fn, rtx arg_size, int fp_code)
{
  int fpret = 0;
  const char *fnname;
  char *secname, *stubname;
  struct mips16_stub *l;
  tree stubid, stubdecl;
  int need_comma;
  unsigned int f;
  rtx insn;

  /* We don't need to do anything if we aren't in mips16 mode, or if
     we were invoked with the -msoft-float option.  */
  if (!TARGET_MIPS16 || TARGET_SOFT_FLOAT_ABI)
    return 0;

  /* Figure out whether the value might come back in a floating point
     register.  */
  if (retval)
    fpret = mips_return_mode_in_fpr_p (GET_MODE (retval));

  /* We don't need to do anything if there were no floating point
     arguments and the value will not be returned in a floating point
     register.  */
  if (fp_code == 0 && ! fpret)
    return 0;

  /* We don't need to do anything if this is a call to a special
     mips16 support function.  */
  if (GET_CODE (fn) == SYMBOL_REF
      && strncmp (XSTR (fn, 0), "__mips16_", 9) == 0)
    return 0;

  /* This code will only work for o32 and o64 abis.  The other ABI's
     require more sophisticated support.  */
  gcc_assert (TARGET_OLDABI);

  /* If we're calling via a function pointer, then we must always call
     via a stub.  There are magic stubs provided in libgcc.a for each
     of the required cases.  Each of them expects the function address
     to arrive in register $2.  */

  if (GET_CODE (fn) != SYMBOL_REF)
    {
      char buf[30];
      tree id;
      rtx stub_fn, insn;

      /* ??? If this code is modified to support other ABI's, we need
         to handle PARALLEL return values here.  */

      if (fpret)
        sprintf (buf, "__mips16_call_stub_%s_%d",
                 mips16_call_stub_mode_suffix (GET_MODE (retval)),
                 fp_code);
      else
        sprintf (buf, "__mips16_call_stub_%d",
                 fp_code);

      id = get_identifier (buf);
      stub_fn = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (id));

      mips_emit_move (gen_rtx_REG (Pmode, 2), fn);

      if (retval == NULL_RTX)
        insn = gen_call_internal (stub_fn, arg_size);
      else
        insn = gen_call_value_internal (retval, stub_fn, arg_size);
      insn = emit_call_insn (insn);

      /* Put the register usage information on the CALL.  */
      CALL_INSN_FUNCTION_USAGE (insn) =
        gen_rtx_EXPR_LIST (VOIDmode,
                           gen_rtx_USE (VOIDmode, gen_rtx_REG (Pmode, 2)),
                           CALL_INSN_FUNCTION_USAGE (insn));

      /* If we are handling a floating point return value, we need to
         save $18 in the function prologue.  Putting a note on the
         call will mean that df_regs_ever_live_p ($18) will be true if the
         call is not eliminated, and we can check that in the prologue
         code.  */
      if (fpret)
        CALL_INSN_FUNCTION_USAGE (insn) =
          gen_rtx_EXPR_LIST (VOIDmode,
                             gen_rtx_USE (VOIDmode,
                                          gen_rtx_REG (word_mode, 18)),
                             CALL_INSN_FUNCTION_USAGE (insn));

      /* Return 1 to tell the caller that we've generated the call
         insn.  */
      return 1;
    }

  /* We know the function we are going to call.  If we have already
     built a stub, we don't need to do anything further.  */

  fnname = targetm.strip_name_encoding (XSTR (fn, 0));
  for (l = mips16_stubs; l != NULL; l = l->next)
    if (strcmp (l->name, fnname) == 0)
      break;

  if (l == NULL)
    {
      /* Build a special purpose stub.  When the linker sees a
         function call in mips16 code, it will check where the target
         is defined.  If the target is a 32-bit call, the linker will
         search for the section defined here.  It can tell which
         symbol this section is associated with by looking at the
         relocation information (the name is unreliable, since this
         might be a static function).  If such a section is found, the
         linker will redirect the call to the start of the magic
         section.

         If the function does not return a floating point value, the
         special stub section is named
             .mips16.call.FNNAME

         If the function does return a floating point value, the stub
         section is named
             .mips16.call.fp.FNNAME
         */

      secname = (char *) alloca (strlen (fnname) + 40);
      sprintf (secname, ".mips16.call.%s%s",
               fpret ? "fp." : "",
               fnname);
      stubname = (char *) alloca (strlen (fnname) + 20);
      sprintf (stubname, "__call_stub_%s%s",
               fpret ? "fp_" : "",
               fnname);
      stubid = get_identifier (stubname);
      stubdecl = build_decl (FUNCTION_DECL, stubid,
                             build_function_type (void_type_node, NULL_TREE));
      DECL_SECTION_NAME (stubdecl) = build_string (strlen (secname), secname);
      DECL_RESULT (stubdecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);

      fprintf (asm_out_file, "\t# Stub function to call %s%s (",
               (fpret
                ? (GET_MODE (retval) == SFmode ? "float " : "double ")
                : ""),
               fnname);
      need_comma = 0;
      for (f = (unsigned int) fp_code; f != 0; f >>= 2)
        {
          fprintf (asm_out_file, "%s%s",
                   need_comma ? ", " : "",
                   (f & 3) == 1 ? "float" : "double");
          need_comma = 1;
        }
      fprintf (asm_out_file, ")\n");

      fprintf (asm_out_file, "\t.set\tnomips16\n");
      assemble_start_function (stubdecl, stubname);

      if (!FUNCTION_NAME_ALREADY_DECLARED)
        {
          fputs ("\t.ent\t", asm_out_file);
          assemble_name (asm_out_file, stubname);
          fputs ("\n", asm_out_file);

          assemble_name (asm_out_file, stubname);
          fputs (":\n", asm_out_file);
        }

      /* We build the stub code by hand.  That's the only way we can
         do it, since we can't generate 32-bit code during a 16-bit
         compilation.  */

      /* We don't want the assembler to insert any nops here.  */
      fprintf (asm_out_file, "\t.set\tnoreorder\n");

      mips16_fp_args (asm_out_file, fp_code, 0);

      if (! fpret)
        {
          fprintf (asm_out_file, "\t.set\tnoat\n");
          fprintf (asm_out_file, "\tla\t%s,%s\n", reg_names[GP_REG_FIRST + 1],
                   fnname);
          fprintf (asm_out_file, "\tjr\t%s\n", reg_names[GP_REG_FIRST + 1]);
          fprintf (asm_out_file, "\t.set\tat\n");
          /* Unfortunately, we can't fill the jump delay slot.  We
             can't fill with one of the mtc1 instructions, because the
             result is not available for one instruction, so if the
             very first instruction in the function refers to the
             register, it will see the wrong value.  */
          fprintf (asm_out_file, "\tnop\n");
        }
      else
        {
          fprintf (asm_out_file, "\tmove\t%s,%s\n",
                   reg_names[GP_REG_FIRST + 18], reg_names[GP_REG_FIRST + 31]);
          fprintf (asm_out_file, "\tjal\t%s\n", fnname);
          /* As above, we can't fill the delay slot.  */
          fprintf (asm_out_file, "\tnop\n");
          switch (GET_MODE (retval))
            {
            case SCmode:
              fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                       reg_names[GP_REG_FIRST + 3],
                       reg_names[FP_REG_FIRST + MAX_FPRS_PER_FMT]);
              /* Fall though.  */
            case SFmode:
              fprintf (asm_out_file, "\tmfc1\t%s,%s\n",
                       reg_names[GP_REG_FIRST + 2],
                       reg_names[FP_REG_FIRST + 0]);
              if (GET_MODE (retval) == SCmode && TARGET_64BIT)
                {
                  /* On 64-bit targets, complex floats are returned in
                     a single GPR, such that "sd" on a suitably-aligned
                     target would store the value correctly.  */
                  fprintf (asm_out_file, "\tdsll\t%s,%s,32\n",
                           reg_names[GP_REG_FIRST + 2 + TARGET_LITTLE_ENDIAN],
                           reg_names[GP_REG_FIRST + 2 + TARGET_LITTLE_ENDIAN]);
                  fprintf (asm_out_file, "\tor\t%s,%s,%s\n",
                           reg_names[GP_REG_FIRST + 2],
                           reg_names[GP_REG_FIRST + 2],
                           reg_names[GP_REG_FIRST + 3]);
                }
              break;

            case DCmode:
              mips16_fpret_double (GP_REG_FIRST + 2 + (8 / UNITS_PER_WORD),
                                   FP_REG_FIRST + MAX_FPRS_PER_FMT);
              /* Fall though.  */
            case DFmode:
            case V2SFmode:
              mips16_fpret_double (GP_REG_FIRST + 2, FP_REG_FIRST + 0);
              break;

            default:
              gcc_unreachable ();
            }
          fprintf (asm_out_file, "\tj\t%s\n", reg_names[GP_REG_FIRST + 18]);
          /* As above, we can't fill the delay slot.  */
          fprintf (asm_out_file, "\tnop\n");
        }

      fprintf (asm_out_file, "\t.set\treorder\n");

#ifdef ASM_DECLARE_FUNCTION_SIZE
      ASM_DECLARE_FUNCTION_SIZE (asm_out_file, stubname, stubdecl);
#endif

      if (!FUNCTION_NAME_ALREADY_DECLARED)
        {
          fputs ("\t.end\t", asm_out_file);
          assemble_name (asm_out_file, stubname);
          fputs ("\n", asm_out_file);
        }

      /* Record this stub.  */
      l = (struct mips16_stub *) xmalloc (sizeof *l);
      l->name = xstrdup (fnname);
      l->fpret = fpret;
      l->next = mips16_stubs;
      mips16_stubs = l;
    }

  /* If we expect a floating point return value, but we've built a
     stub which does not expect one, then we're in trouble.  We can't
     use the existing stub, because it won't handle the floating point
     value.  We can't build a new stub, because the linker won't know
     which stub to use for the various calls in this object file.
     Fortunately, this case is illegal, since it means that a function
     was declared in two different ways in a single compilation.  */
  if (fpret && ! l->fpret)
    error ("cannot handle inconsistent calls to %qs", fnname);

  if (retval == NULL_RTX)
    insn = gen_call_internal_direct (fn, arg_size);
  else
    insn = gen_call_value_internal_direct (retval, fn, arg_size);
  insn = emit_call_insn (insn);

  /* If we are calling a stub which handles a floating point return
     value, we need to arrange to save $18 in the prologue.  We do
     this by marking the function call as using the register.  The
     prologue will later see that it is used, and emit code to save
     it.  */
  if (l->fpret)
    CALL_INSN_FUNCTION_USAGE (insn) =
      gen_rtx_EXPR_LIST (VOIDmode,
                         gen_rtx_USE (VOIDmode, gen_rtx_REG (word_mode, 18)),
                         CALL_INSN_FUNCTION_USAGE (insn));

  /* Return 1 to tell the caller that we've generated the call
     insn.  */
  return 1;
}
\f
/* Return true if calls to X can use R_MIPS_CALL* relocations.  */

static bool
mips_ok_for_lazy_binding_p (rtx x)
{
  return (TARGET_USE_GOT
          && GET_CODE (x) == SYMBOL_REF
          && !mips_symbol_binds_local_p (x));
}

/* Load function address ADDR into register DEST.  SIBCALL_P is true
   if the address is needed for a sibling call.  Return true if we
   used an explicit lazy-binding sequence.  */

static bool
mips_load_call_address (rtx dest, rtx addr, int sibcall_p)
{
  /* If we're generating PIC, and this call is to a global function,
     try to allow its address to be resolved lazily.  This isn't
     possible if TARGET_CALL_SAVED_GP since the value of $gp on entry
     to the stub would be our caller's gp, not ours.  */
  if (TARGET_EXPLICIT_RELOCS
      && !(sibcall_p && TARGET_CALL_SAVED_GP)
      && mips_ok_for_lazy_binding_p (addr))
    {
      rtx high, lo_sum_symbol;

      high = mips_unspec_offset_high (dest, pic_offset_table_rtx,
                                      addr, SYMBOL_GOTOFF_CALL);
      lo_sum_symbol = mips_unspec_address (addr, SYMBOL_GOTOFF_CALL);
      if (Pmode == SImode)
        emit_insn (gen_load_callsi (dest, high, lo_sum_symbol));
      else
        emit_insn (gen_load_calldi (dest, high, lo_sum_symbol));
      return true;
    }
  else
    {
      mips_emit_move (dest, addr);
      return false;
    }
}


/* Expand a call or call_value instruction.  RESULT is where the
   result will go (null for calls), ADDR is the address of the
   function, ARGS_SIZE is the size of the arguments and AUX is
   the value passed to us by mips_function_arg.  SIBCALL_P is true
   if we are expanding a sibling call, false if we're expanding
   a normal call.  */

void
mips_expand_call (rtx result, rtx addr, rtx args_size, rtx aux, int sibcall_p)
{
  rtx orig_addr, pattern, insn;
  bool lazy_p;

  orig_addr = addr;
  lazy_p = false;
  if (!call_insn_operand (addr, VOIDmode))
    {
      addr = gen_reg_rtx (Pmode);
      lazy_p = mips_load_call_address (addr, orig_addr, sibcall_p);
    }

  if (TARGET_MIPS16
      && TARGET_HARD_FLOAT_ABI
      && build_mips16_call_stub (result, addr, args_size,
                                 aux == 0 ? 0 : (int) GET_MODE (aux)))
    return;

  if (result == 0)
    pattern = (sibcall_p
               ? gen_sibcall_internal (addr, args_size)
               : gen_call_internal (addr, args_size));
  else if (GET_CODE (result) == PARALLEL && XVECLEN (result, 0) == 2)
    {
      rtx reg1, reg2;

      reg1 = XEXP (XVECEXP (result, 0, 0), 0);
      reg2 = XEXP (XVECEXP (result, 0, 1), 0);
      pattern =
        (sibcall_p
         ? gen_sibcall_value_multiple_internal (reg1, addr, args_size, reg2)
         : gen_call_value_multiple_internal (reg1, addr, args_size, reg2));
    }
  else
    pattern = (sibcall_p
               ? gen_sibcall_value_internal (result, addr, args_size)
               : gen_call_value_internal (result, addr, args_size));

  insn = emit_call_insn (pattern);

  /* Lazy-binding stubs require $gp to be valid on entry.  We also pretend
     that they use FAKE_CALL_REGNO; see the load_call<mode> patterns for
     details.  */
  if (lazy_p)
    {
      use_reg (&CALL_INSN_FUNCTION_USAGE (insn), pic_offset_table_rtx);
      use_reg (&CALL_INSN_FUNCTION_USAGE (insn),
               gen_rtx_REG (Pmode, FAKE_CALL_REGNO));
    }
}


/* Implement TARGET_FUNCTION_OK_FOR_SIBCALL.  */

static bool
mips_function_ok_for_sibcall (tree decl, tree exp ATTRIBUTE_UNUSED)
{
  if (!TARGET_SIBCALLS)
    return false;

  /* We can't do a sibcall if the called function is a MIPS16 function
     because there is no direct "jx" instruction equivalent to "jalx" to
     switch the ISA mode.  */
  if (mips_use_mips16_mode_p (decl))
    return false;

  /* ...and when -minterlink-mips16 is in effect, assume that external
     functions could be MIPS16 ones unless an attribute explicitly
     tells us otherwise.  We only care about cases where the sibling
     and normal calls would both be direct.  */
  if (TARGET_INTERLINK_MIPS16
      && decl
      && DECL_EXTERNAL (decl)
      && !mips_nomips16_decl_p (decl)
      && const_call_insn_operand (XEXP (DECL_RTL (decl), 0), VOIDmode))
    return false;

  /* Otherwise OK.  */
  return true;
}
\f
/* Emit code to move general operand SRC into condition-code
   register DEST.  SCRATCH is a scratch TFmode float register.
   The sequence is:

        FP1 = SRC
        FP2 = 0.0f
        DEST = FP2 < FP1

   where FP1 and FP2 are single-precision float registers
   taken from SCRATCH.  */

void
mips_emit_fcc_reload (rtx dest, rtx src, rtx scratch)
{
  rtx fp1, fp2;

  /* Change the source to SFmode.  */
  if (MEM_P (src))
    src = adjust_address (src, SFmode, 0);
  else if (REG_P (src) || GET_CODE (src) == SUBREG)
    src = gen_rtx_REG (SFmode, true_regnum (src));

  fp1 = gen_rtx_REG (SFmode, REGNO (scratch));
  fp2 = gen_rtx_REG (SFmode, REGNO (scratch) + MAX_FPRS_PER_FMT);

  mips_emit_move (copy_rtx (fp1), src);
  mips_emit_move (copy_rtx (fp2), CONST0_RTX (SFmode));
  emit_insn (gen_slt_sf (dest, fp2, fp1));
}
\f
/* Emit straight-line code to move LENGTH bytes from SRC to DEST.
   Assume that the areas do not overlap.  */

static void
mips_block_move_straight (rtx dest, rtx src, HOST_WIDE_INT length)
{
  HOST_WIDE_INT offset, delta;
  unsigned HOST_WIDE_INT bits;
  int i;
  enum machine_mode mode;
  rtx *regs;

  /* Work out how many bits to move at a time.  If both operands have
     half-word alignment, it is usually better to move in half words.
     For instance, lh/lh/sh/sh is usually better than lwl/lwr/swl/swr
     and lw/lw/sw/sw is usually better than ldl/ldr/sdl/sdr.
     Otherwise move word-sized chunks.  */
  if (MEM_ALIGN (src) == BITS_PER_WORD / 2
      && MEM_ALIGN (dest) == BITS_PER_WORD / 2)
    bits = BITS_PER_WORD / 2;
  else
    bits = BITS_PER_WORD;

  mode = mode_for_size (bits, MODE_INT, 0);
  delta = bits / BITS_PER_UNIT;

  /* Allocate a buffer for the temporary registers.  */
  regs = alloca (sizeof (rtx) * length / delta);

  /* Load as many BITS-sized chunks as possible.  Use a normal load if
     the source has enough alignment, otherwise use left/right pairs.  */
  for (offset = 0, i = 0; offset + delta <= length; offset += delta, i++)
    {
      regs[i] = gen_reg_rtx (mode);
      if (MEM_ALIGN (src) >= bits)
        mips_emit_move (regs[i], adjust_address (src, mode, offset));
      else
        {
          rtx part = adjust_address (src, BLKmode, offset);
          if (!mips_expand_unaligned_load (regs[i], part, bits, 0))
            gcc_unreachable ();
        }
    }

  /* Copy the chunks to the destination.  */
  for (offset = 0, i = 0; offset + delta <= length; offset += delta, i++)
    if (MEM_ALIGN (dest) >= bits)
      mips_emit_move (adjust_address (dest, mode, offset), regs[i]);
    else
      {
        rtx part = adjust_address (dest, BLKmode, offset);
        if (!mips_expand_unaligned_store (part, regs[i], bits, 0))
          gcc_unreachable ();
      }

  /* Mop up any left-over bytes.  */
  if (offset < length)
    {
      src = adjust_address (src, BLKmode, offset);
      dest = adjust_address (dest, BLKmode, offset);
      move_by_pieces (dest, src, length - offset,
                      MIN (MEM_ALIGN (src), MEM_ALIGN (dest)), 0);
    }
}
\f
#define MAX_MOVE_REGS 4
#define MAX_MOVE_BYTES (MAX_MOVE_REGS * UNITS_PER_WORD)


/* Helper function for doing a loop-based block operation on memory
   reference MEM.  Each iteration of the loop will operate on LENGTH
   bytes of MEM.

   Create a new base register for use within the loop and point it to
   the start of MEM.  Create a new memory reference that uses this
   register.  Store them in *LOOP_REG and *LOOP_MEM respectively.  */

static void
mips_adjust_block_mem (rtx mem, HOST_WIDE_INT length,
                       rtx *loop_reg, rtx *loop_mem)
{
  *loop_reg = copy_addr_to_reg (XEXP (mem, 0));

  /* Although the new mem does not refer to a known location,
     it does keep up to LENGTH bytes of alignment.  */
  *loop_mem = change_address (mem, BLKmode, *loop_reg);
  set_mem_align (*loop_mem, MIN (MEM_ALIGN (mem), length * BITS_PER_UNIT));
}


/* Move LENGTH bytes from SRC to DEST using a loop that moves MAX_MOVE_BYTES
   per iteration.  LENGTH must be at least MAX_MOVE_BYTES.  Assume that the
   memory regions do not overlap.  */

static void
mips_block_move_loop (rtx dest, rtx src, HOST_WIDE_INT length)
{
  rtx label, src_reg, dest_reg, final_src;
  HOST_WIDE_INT leftover;

  leftover = length % MAX_MOVE_BYTES;
  length -= leftover;

  /* Create registers and memory references for use within the loop.  */
  mips_adjust_block_mem (src, MAX_MOVE_BYTES, &src_reg, &src);
  mips_adjust_block_mem (dest, MAX_MOVE_BYTES, &dest_reg, &dest);

  /* Calculate the value that SRC_REG should have after the last iteration
     of the loop.  */
  final_src = expand_simple_binop (Pmode, PLUS, src_reg, GEN_INT (length),
                                   0, 0, OPTAB_WIDEN);

  /* Emit the start of the loop.  */
  label = gen_label_rtx ();
  emit_label (label);

  /* Emit the loop body.  */
  mips_block_move_straight (dest, src, MAX_MOVE_BYTES);

  /* Move on to the next block.  */
  mips_emit_move (src_reg, plus_constant (src_reg, MAX_MOVE_BYTES));
  mips_emit_move (dest_reg, plus_constant (dest_reg, MAX_MOVE_BYTES));

  /* Emit the loop condition.  */
  if (Pmode == DImode)
    emit_insn (gen_cmpdi (src_reg, final_src));
  else
    emit_insn (gen_cmpsi (src_reg, final_src));
  emit_jump_insn (gen_bne (label));

  /* Mop up any left-over bytes.  */
  if (leftover)
    mips_block_move_straight (dest, src, leftover);
}

/* Expand a movmemsi instruction.  */

bool
mips_expand_block_move (rtx dest, rtx src, rtx length)
{
  if (GET_CODE (length) == CONST_INT)
    {
      if (INTVAL (length) <= 2 * MAX_MOVE_BYTES)
        {
          mips_block_move_straight (dest, src, INTVAL (length));
          return true;
        }
      else if (optimize)
        {
          mips_block_move_loop (dest, src, INTVAL (length));
          return true;
        }
    }
  return false;
}
\f

/* Expand a loop of synci insns for the address range [BEGIN, END).  */

void
mips_expand_synci_loop (rtx begin, rtx end)
{
  rtx inc, label, cmp, cmp_result;

  /* Load INC with the cache line size (rdhwr INC,$1). */
  inc = gen_reg_rtx (SImode);
  emit_insn (gen_rdhwr (inc, const1_rtx));

  /* Loop back to here.  */
  label = gen_label_rtx ();
  emit_label (label);

  emit_insn (gen_synci (begin));

  cmp = gen_reg_rtx (Pmode);
  mips_emit_binary (GTU, cmp, begin, end);

  mips_emit_binary (PLUS, begin, begin, inc);

  cmp_result = gen_rtx_EQ (VOIDmode, cmp, const0_rtx);
  emit_jump_insn (gen_condjump (cmp_result, label));
}
\f
/* Return true if it is possible to use left/right accesses for a
   bitfield of WIDTH bits starting BITPOS bits into *OP.  When
   returning true, update *OP, *LEFT and *RIGHT as follows:

   *OP is a BLKmode reference to the whole field.

   *LEFT is a QImode reference to the first byte if big endian or
   the last byte if little endian.  This address can be used in the
   left-side instructions (lwl, swl, ldl, sdl).

   *RIGHT is a QImode reference to the opposite end of the field and
   can be used in the patterning right-side instruction.  */

static bool
mips_get_unaligned_mem (rtx *op, unsigned int width, int bitpos,
                        rtx *left, rtx *right)
{
  rtx first, last;

  /* Check that the operand really is a MEM.  Not all the extv and
     extzv predicates are checked.  */
  if (!MEM_P (*op))
    return false;

  /* Check that the size is valid.  */
  if (width != 32 && (!TARGET_64BIT || width != 64))
    return false;

  /* We can only access byte-aligned values.  Since we are always passed
     a reference to the first byte of the field, it is not necessary to
     do anything with BITPOS after this check.  */
  if (bitpos % BITS_PER_UNIT != 0)
    return false;

  /* Reject aligned bitfields: we want to use a normal load or store
     instead of a left/right pair.  */
  if (MEM_ALIGN (*op) >= width)
    return false;

  /* Adjust *OP to refer to the whole field.  This also has the effect
     of legitimizing *OP's address for BLKmode, possibly simplifying it.  */
  *op = adjust_address (*op, BLKmode, 0);
  set_mem_size (*op, GEN_INT (width / BITS_PER_UNIT));

  /* Get references to both ends of the field.  We deliberately don't
     use the original QImode *OP for FIRST since the new BLKmode one
     might have a simpler address.  */
  first = adjust_address (*op, QImode, 0);
  last = adjust_address (*op, QImode, width / BITS_PER_UNIT - 1);

  /* Allocate to LEFT and RIGHT according to endianness.  LEFT should
     be the upper word and RIGHT the lower word.  */
  if (TARGET_BIG_ENDIAN)
    *left = first, *right = last;
  else
    *left = last, *right = first;

  return true;
}


/* Try to emit the equivalent of (set DEST (zero_extract SRC WIDTH BITPOS)).
   Return true on success.  We only handle cases where zero_extract is
   equivalent to sign_extract.  */

bool
mips_expand_unaligned_load (rtx dest, rtx src, unsigned int width, int bitpos)
{
  rtx left, right, temp;

  /* If TARGET_64BIT, the destination of a 32-bit load will be a
     paradoxical word_mode subreg.  This is the only case in which
     we allow the destination to be larger than the source.  */
  if (GET_CODE (dest) == SUBREG
      && GET_MODE (dest) == DImode
      && SUBREG_BYTE (dest) == 0
      && GET_MODE (SUBREG_REG (dest)) == SImode)
    dest = SUBREG_REG (dest);

  /* After the above adjustment, the destination must be the same
     width as the source.  */
  if (GET_MODE_BITSIZE (GET_MODE (dest)) != width)
    return false;

  if (!mips_get_unaligned_mem (&src, width, bitpos, &left, &right))
    return false;

  temp = gen_reg_rtx (GET_MODE (dest));
  if (GET_MODE (dest) == DImode)
    {
      emit_insn (gen_mov_ldl (temp, src, left));
      emit_insn (gen_mov_ldr (dest, copy_rtx (src), right, temp));
    }
  else
    {
      emit_insn (gen_mov_lwl (temp, src, left));
      emit_insn (gen_mov_lwr (dest, copy_rtx (src), right, temp));
    }
  return true;
}


/* Try to expand (set (zero_extract DEST WIDTH BITPOS) SRC).  Return
   true on success.  */

bool
mips_expand_unaligned_store (rtx dest, rtx src, unsigned int width, int bitpos)
{
  rtx left, right;
  enum machine_mode mode;

  if (!mips_get_unaligned_mem (&dest, width, bitpos, &left, &right))
    return false;

  mode = mode_for_size (width, MODE_INT, 0);
  src = gen_lowpart (mode, src);

  if (mode == DImode)
    {
      emit_insn (gen_mov_sdl (dest, src, left));
      emit_insn (gen_mov_sdr (copy_rtx (dest), copy_rtx (src), right));
    }
  else
    {
      emit_insn (gen_mov_swl (dest, src, left));
      emit_insn (gen_mov_swr (copy_rtx (dest), copy_rtx (src), right));
    }
  return true;
}

/* Return true if X is a MEM with the same size as MODE.  */

bool
mips_mem_fits_mode_p (enum machine_mode mode, rtx x)
{
  rtx size;

  if (!MEM_P (x))
    return false;

  size = MEM_SIZE (x);
  return size && INTVAL (size) == GET_MODE_SIZE (mode);
}

/* Return true if (zero_extract OP SIZE POSITION) can be used as the
   source of an "ext" instruction or the destination of an "ins"
   instruction.  OP must be a register operand and the following
   conditions must hold:

     0 <= POSITION < GET_MODE_BITSIZE (GET_MODE (op))
     0 < SIZE <= GET_MODE_BITSIZE (GET_MODE (op))
     0 < POSITION + SIZE <= GET_MODE_BITSIZE (GET_MODE (op))

   Also reject lengths equal to a word as they are better handled
   by the move patterns.  */

bool
mips_use_ins_ext_p (rtx op, rtx size, rtx position)
{
  HOST_WIDE_INT len, pos;

  if (!ISA_HAS_EXT_INS
      || !register_operand (op, VOIDmode)
      || GET_MODE_BITSIZE (GET_MODE (op)) > BITS_PER_WORD)
    return false;

  len = INTVAL (size);
  pos = INTVAL (position);

  if (len <= 0 || len >= GET_MODE_BITSIZE (GET_MODE (op))
      || pos < 0 || pos + len > GET_MODE_BITSIZE (GET_MODE (op)))
    return false;

  return true;
}
\f
/* Initialize mips_split_addresses from the associated command-line
   settings.

   mips_split_addresses is a half-way house between explicit
   relocations and the traditional assembler macros.  It can
   split absolute 32-bit symbolic constants into a high/lo_sum
   pair but uses macros for other sorts of access.

   Like explicit relocation support for REL targets, it relies
   on GNU extensions in the assembler and the linker.

   Although this code should work for -O0, it has traditionally
   been treated as an optimization.  */

static void
mips_init_split_addresses (void)
{
  if (!TARGET_MIPS16 && TARGET_SPLIT_ADDRESSES
      && optimize && !flag_pic
      && !ABI_HAS_64BIT_SYMBOLS)
    mips_split_addresses = 1;
  else
    mips_split_addresses = 0;
}

/* (Re-)Initialize information about relocs.  */

static void
mips_init_relocs (void)
{
  memset (mips_split_p, '\0', sizeof (mips_split_p));
  memset (mips_hi_relocs, '\0', sizeof (mips_hi_relocs));
  memset (mips_lo_relocs, '\0', sizeof (mips_lo_relocs));

  if (ABI_HAS_64BIT_SYMBOLS)
    {
      if (TARGET_EXPLICIT_RELOCS)
        {
          mips_split_p[SYMBOL_64_HIGH] = true;
          mips_hi_relocs[SYMBOL_64_HIGH] = "%highest(";
          mips_lo_relocs[SYMBOL_64_HIGH] = "%higher(";

          mips_split_p[SYMBOL_64_MID] = true;
          mips_hi_relocs[SYMBOL_64_MID] = "%higher(";
          mips_lo_relocs[SYMBOL_64_MID] = "%hi(";

          mips_split_p[SYMBOL_64_LOW] = true;
          mips_hi_relocs[SYMBOL_64_LOW] = "%hi(";
          mips_lo_relocs[SYMBOL_64_LOW] = "%lo(";

          mips_split_p[SYMBOL_ABSOLUTE] = true;
          mips_lo_relocs[SYMBOL_ABSOLUTE] = "%lo(";
        }
    }
  else
    {
      if (TARGET_EXPLICIT_RELOCS || mips_split_addresses || TARGET_MIPS16)
        {
          mips_split_p[SYMBOL_ABSOLUTE] = true;
          mips_hi_relocs[SYMBOL_ABSOLUTE] = "%hi(";
          mips_lo_relocs[SYMBOL_ABSOLUTE] = "%lo(";

          mips_lo_relocs[SYMBOL_32_HIGH] = "%hi(";
        }
    }

  if (TARGET_MIPS16)
    {
      /* The high part is provided by a pseudo copy of $gp.  */
      mips_split_p[SYMBOL_GP_RELATIVE] = true;
      mips_lo_relocs[SYMBOL_GP_RELATIVE] = "%gprel(";
    }

  if (TARGET_EXPLICIT_RELOCS)
    {
      /* Small data constants are kept whole until after reload,
         then lowered by mips_rewrite_small_data.  */
      mips_lo_relocs[SYMBOL_GP_RELATIVE] = "%gp_rel(";

      mips_split_p[SYMBOL_GOT_PAGE_OFST] = true;
      if (TARGET_NEWABI)
        {
          mips_lo_relocs[SYMBOL_GOTOFF_PAGE] = "%got_page(";
          mips_lo_relocs[SYMBOL_GOT_PAGE_OFST] = "%got_ofst(";
        }
      else
        {
          mips_lo_relocs[SYMBOL_GOTOFF_PAGE] = "%got(";
          mips_lo_relocs[SYMBOL_GOT_PAGE_OFST] = "%lo(";
        }

      if (TARGET_XGOT)
        {
          /* The HIGH and LO_SUM are matched by special .md patterns.  */
          mips_split_p[SYMBOL_GOT_DISP] = true;

          mips_split_p[SYMBOL_GOTOFF_DISP] = true;
          mips_hi_relocs[SYMBOL_GOTOFF_DISP] = "%got_hi(";
          mips_lo_relocs[SYMBOL_GOTOFF_DISP] = "%got_lo(";

          mips_split_p[SYMBOL_GOTOFF_CALL] = true;
          mips_hi_relocs[SYMBOL_GOTOFF_CALL] = "%call_hi(";
          mips_lo_relocs[SYMBOL_GOTOFF_CALL] = "%call_lo(";
        }
      else
        {
          if (TARGET_NEWABI)
            mips_lo_relocs[SYMBOL_GOTOFF_DISP] = "%got_disp(";
          else
            mips_lo_relocs[SYMBOL_GOTOFF_DISP] = "%got(";
          mips_lo_relocs[SYMBOL_GOTOFF_CALL] = "%call16(";
        }
    }

  if (TARGET_NEWABI)
    {
      mips_split_p[SYMBOL_GOTOFF_LOADGP] = true;
      mips_hi_relocs[SYMBOL_GOTOFF_LOADGP] = "%hi(%neg(%gp_rel(";
      mips_lo_relocs[SYMBOL_GOTOFF_LOADGP] = "%lo(%neg(%gp_rel(";
    }

  /* Thread-local relocation operators.  */
  mips_lo_relocs[SYMBOL_TLSGD] = "%tlsgd(";
  mips_lo_relocs[SYMBOL_TLSLDM] = "%tlsldm(";
  mips_split_p[SYMBOL_DTPREL] = 1;
  mips_hi_relocs[SYMBOL_DTPREL] = "%dtprel_hi(";
  mips_lo_relocs[SYMBOL_DTPREL] = "%dtprel_lo(";
  mips_lo_relocs[SYMBOL_GOTTPREL] = "%gottprel(";
  mips_split_p[SYMBOL_TPREL] = 1;
  mips_hi_relocs[SYMBOL_TPREL] = "%tprel_hi(";
  mips_lo_relocs[SYMBOL_TPREL] = "%tprel_lo(";

  mips_lo_relocs[SYMBOL_HALF] = "%half(";
}

/* If OP is an UNSPEC address, return the address to which it refers,
   otherwise return OP itself.  */

static rtx
mips_strip_unspec_address (rtx op)
{
  rtx base, offset;

  split_const (op, &base, &offset);
  if (UNSPEC_ADDRESS_P (base))
    op = plus_constant (UNSPEC_ADDRESS (base), INTVAL (offset));
  return op;
}

/* Print symbolic operand OP, which is part of a HIGH or LO_SUM
   in context CONTEXT.  RELOCS is the array of relocations to use.  */

static void
print_operand_reloc (FILE *file, rtx op, enum mips_symbol_context context,
                     const char **relocs)
{
  enum mips_symbol_type symbol_type;
  const char *p;

  symbol_type = mips_classify_symbolic_expression (op, context);
  if (relocs[symbol_type] == 0)
    fatal_insn ("PRINT_OPERAND, invalid operand for relocation", op);

  fputs (relocs[symbol_type], file);
  output_addr_const (file, mips_strip_unspec_address (op));
  for (p = relocs[symbol_type]; *p != 0; p++)
    if (*p == '(')
      fputc (')', file);
}

/* Print the text for PRINT_OPERAND punctation character CH to FILE.
   The punctuation characters are:

   '('  Start a nested ".set noreorder" block.
   ')'  End a nested ".set noreorder" block.
   '['  Start a nested ".set noat" block.
   ']'  End a nested ".set noat" block.
   '<'  Start a nested ".set nomacro" block.
   '>'  End a nested ".set nomacro" block.
   '*'  Behave like %(%< if generating a delayed-branch sequence.
   '#'  Print a nop if in a ".set noreorder" block.
   '/'  Like '#', but do nothing within a delayed-branch sequence.
   '?'  Print "l" if mips_branch_likely is true
   '.'  Print the name of the register with a hard-wired zero (zero or $0).
   '@'  Print the name of the assembler temporary register (at or $1).
   '^'  Print the name of the pic call-through register (t9 or $25).
   '+'  Print the name of the gp register (usually gp or $28).
   '$'  Print the name of the stack pointer register (sp or $29).
   '|'  Print ".set push; .set mips2" if !ISA_HAS_LL_SC.
   '-'  Print ".set pop" under the same conditions for '|'.

   See also mips_init_print_operand_pucnt.  */

static void
mips_print_operand_punctuation (FILE *file, int ch)
{
  switch (ch)
    {
    case '(':
      if (set_noreorder++ == 0)
        fputs (".set\tnoreorder\n\t", file);
      break;

    case ')':
      gcc_assert (set_noreorder > 0);
      if (--set_noreorder == 0)
        fputs ("\n\t.set\treorder", file);
      break;

    case '[':
      if (set_noat++ == 0)
        fputs (".set\tnoat\n\t", file);
      break;

    case ']':
      gcc_assert (set_noat > 0);
      if (--set_noat == 0)
        fputs ("\n\t.set\tat", file);
      break;

    case '<':
      if (set_nomacro++ == 0)
        fputs (".set\tnomacro\n\t", file);
      break;

    case '>':
      gcc_assert (set_nomacro > 0);
      if (--set_nomacro == 0)
        fputs ("\n\t.set\tmacro", file);
      break;

    case '*':
      if (final_sequence != 0)
        {
          mips_print_operand_punctuation (file, '(');
          mips_print_operand_punctuation (file, '<');
        }
      break;

    case '#':
      if (set_noreorder != 0)
        fputs ("\n\tnop", file);
      break;

    case '/':
      /* Print an extra newline so that the delayed insn is separated
         from the following ones.  This looks neater and is consistent
         with non-nop delayed sequences.  */
      if (set_noreorder != 0 && final_sequence == 0)
        fputs ("\n\tnop\n", file);
      break;

    case '?':
      if (mips_branch_likely)
        putc ('l', file);
      break;

    case '.':
      fputs (reg_names[GP_REG_FIRST + 0], file);
      break;

    case '@':
      fputs (reg_names[GP_REG_FIRST + 1], file);
      break;

    case '^':
      fputs (reg_names[PIC_FUNCTION_ADDR_REGNUM], file);
      break;

    case '+':
      fputs (reg_names[PIC_OFFSET_TABLE_REGNUM], file);
      break;

    case '$':
      fputs (reg_names[STACK_POINTER_REGNUM], file);
      break;

    case '|':
      if (!ISA_HAS_LL_SC)
        fputs (".set\tpush\n\t.set\tmips2\n\t", file);
      break;

    case '-':
      if (!ISA_HAS_LL_SC)
        fputs ("\n\t.set\tpop", file);
      break;

    default:
      gcc_unreachable ();
      break;
    }
}

/* Initialize mips_print_operand_punct.  */

static void
mips_init_print_operand_punct (void)
{
  const char *p;

  for (p = "()[]<>*#/?.@^+$|-"; *p; p++)
    mips_print_operand_punct[(unsigned char) *p] = true;
}

/* PRINT_OPERAND prefix LETTER refers to the integer branch instruction
   associated with condition CODE.  Print the condition part of the
   opcode to FILE.  */

static void
mips_print_int_branch_condition (FILE *file, enum rtx_code code, int letter)
{
  switch (code)
    {
    case EQ:
    case NE:
    case GT:
    case GE:
    case LT:
    case LE:
    case GTU:
    case GEU:
    case LTU:
    case LEU:
      /* Conveniently, the MIPS names for these conditions are the same
         as their RTL equivalents.  */
      fputs (GET_RTX_NAME (code), file);
      break;

    default:
      output_operand_lossage ("'%%%c' is not a valid operand prefix", letter);
      break;
    }
}

/* Likewise floating-point branches.  */

static void
mips_print_float_branch_condition (FILE *file, enum rtx_code code, int letter)
{
  switch (code)
    {
    case EQ:
      fputs ("c1f", file);
      break;

    case NE:
      fputs ("c1t", file);
      break;

    default:
      output_operand_lossage ("'%%%c' is not a valid operand prefix", letter);
      break;
    }
}

/* Implement the PRINT_OPERAND macro.  The MIPS-specific operand codes are:

   'X'  Print CONST_INT OP in hexadecimal format.
   'x'  Print the low 16 bits of CONST_INT OP in hexadecimal format.
   'd'  Print CONST_INT OP in decimal.
   'h'  Print the high-part relocation associated with OP, after stripping
          any outermost HIGH.
   'R'  Print the low-part relocation associated with OP.
   'C'  Print the integer branch condition for comparison OP.
   'N'  Print the inverse of the integer branch condition for comparison OP.
   'F'  Print the FPU branch condition for comparison OP.
   'W'  Print the inverse of the FPU branch condition for comparison OP.
   'T'  Print 'f' for (eq:CC ...), 't' for (ne:CC ...),
              'z' for (eq:?I ...), 'n' for (ne:?I ...).
   't'  Like 'T', but with the EQ/NE cases reversed
   'Y'  Print mips_fp_conditions[INTVAL (OP)]
   'Z'  Print OP and a comma for ISA_HAS_8CC, otherwise print nothing.
   'q'  Print a DSP accumulator register.
   'D'  Print the second part of a double-word register or memory operand.
   'L'  Print the low-order register in a double-word register operand.
   'M'  Print high-order register in a double-word register operand.
   'z'  Print $0 if OP is zero, otherwise print OP normally.  */

void
print_operand (FILE *file, rtx op, int letter)
{
  enum rtx_code code;

  if (PRINT_OPERAND_PUNCT_VALID_P (letter))
    {
      mips_print_operand_punctuation (file, letter);
      return;
    }

  gcc_assert (op);
  code = GET_CODE (op);

  switch (letter)
    {
    case 'X':
      if (GET_CODE (op) == CONST_INT)
        fprintf (file, HOST_WIDE_INT_PRINT_HEX, INTVAL (op));
      else
        output_operand_lossage ("invalid use of '%%%c'", letter);
      break;

    case 'x':
      if (GET_CODE (op) == CONST_INT)
        fprintf (file, HOST_WIDE_INT_PRINT_HEX, INTVAL (op) & 0xffff);
      else
        output_operand_lossage ("invalid use of '%%%c'", letter);
      break;

    case 'd':
      if (GET_CODE (op) == CONST_INT)
        fprintf (file, HOST_WIDE_INT_PRINT_DEC, INTVAL (op));
      else
        output_operand_lossage ("invalid use of '%%%c'", letter);
      break;

    case 'h':
      if (code == HIGH)
        op = XEXP (op, 0);
      print_operand_reloc (file, op, SYMBOL_CONTEXT_LEA, mips_hi_relocs);
      break;

    case 'R':
      print_operand_reloc (file, op, SYMBOL_CONTEXT_LEA, mips_lo_relocs);
      break;

    case 'C':
      mips_print_int_branch_condition (file, code, letter);
      break;

    case 'N':
      mips_print_int_branch_condition (file, reverse_condition (code), letter);
      break;

    case 'F':
      mips_print_float_branch_condition (file, code, letter);
      break;

    case 'W':
      mips_print_float_branch_condition (file, reverse_condition (code),
                                         letter);
      break;

    case 'T':
    case 't':
      {
        int truth = (code == NE) == (letter == 'T');
        fputc ("zfnt"[truth * 2 + (GET_MODE (op) == CCmode)], file);
      }
      break;

    case 'Y':
      if (code == CONST_INT && UINTVAL (op) < ARRAY_SIZE (mips_fp_conditions))
        fputs (mips_fp_conditions[UINTVAL (op)], file);
      else
        output_operand_lossage ("'%%%c' is not a valid operand prefix",
                                letter);
      break;

    case 'Z':
      if (ISA_HAS_8CC)
        {
          print_operand (file, op, 0);
          fputc (',', file);
        }
      break;

    case 'q':
      if (code == REG && MD_REG_P (REGNO (op)))
        fprintf (file, "$ac0");
      else if (code == REG && DSP_ACC_REG_P (REGNO (op)))
        fprintf (file, "$ac%c", reg_names[REGNO (op)][3]);
      else
        output_operand_lossage ("invalid use of '%%%c'", letter);
      break;

    default:
      switch (code)
        {
        case REG:
          {
            unsigned int regno = REGNO (op);
            if ((letter == 'M' && TARGET_LITTLE_ENDIAN)
                || (letter == 'L' && TARGET_BIG_ENDIAN)
                || letter == 'D')
              regno++;
            fprintf (file, "%s", reg_names[regno]);
          }
          break;

        case MEM:
          if (letter == 'D')
            output_address (plus_constant (XEXP (op, 0), 4));
          else
            output_address (XEXP (op, 0));
          break;

        default:
          if (letter == 'z' && op == CONST0_RTX (GET_MODE (op)))
            fputs (reg_names[GP_REG_FIRST], file);
          else if (CONST_GP_P (op))
            fputs (reg_names[GLOBAL_POINTER_REGNUM], file);
          else
            output_addr_const (file, mips_strip_unspec_address (op));
          break;
        }
    }
}

/* Output address operand X to FILE.  */

void
print_operand_address (FILE *file, rtx x)
{
  struct mips_address_info addr;

  if (mips_classify_address (&addr, x, word_mode, true))
    switch (addr.type)
      {
      case ADDRESS_REG:
        print_operand (file, addr.offset, 0);
        fprintf (file, "(%s)", reg_names[REGNO (addr.reg)]);
        return;

      case ADDRESS_LO_SUM:
        print_operand_reloc (file, addr.offset, SYMBOL_CONTEXT_MEM,
                             mips_lo_relocs);
        fprintf (file, "(%s)", reg_names[REGNO (addr.reg)]);
        return;

      case ADDRESS_CONST_INT:
        output_addr_const (file, x);
        fprintf (file, "(%s)", reg_names[0]);
        return;

      case ADDRESS_SYMBOLIC:
        output_addr_const (file, mips_strip_unspec_address (x));
        return;
      }
  gcc_unreachable ();
}
\f
/* Set SYMBOL_REF_FLAGS for the SYMBOL_REF inside RTL, which belongs to DECL.
   FIRST is true if this is the first time handling this decl.  */

static void
mips_encode_section_info (tree decl, rtx rtl, int first)
{
  default_encode_section_info (decl, rtl, first);

  if (TREE_CODE (decl) == FUNCTION_DECL)
    {
      rtx symbol = XEXP (rtl, 0);
      tree type = TREE_TYPE (decl);

      if ((TARGET_LONG_CALLS && !mips_near_type_p (type))
          || mips_far_type_p (type))
        SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LONG_CALL;
    }
}

/* Implement TARGET_SELECT_RTX_SECTION.  */

static section *
mips_select_rtx_section (enum machine_mode mode, rtx x,
                         unsigned HOST_WIDE_INT align)
{
  /* ??? Consider using mergeable small data sections.  */
  if (mips_rtx_constant_in_small_data_p (mode))
    return get_named_section (NULL, ".sdata", 0);

  return default_elf_select_rtx_section (mode, x, align);
}

/* Implement TARGET_ASM_FUNCTION_RODATA_SECTION.

   The complication here is that, with the combination TARGET_ABICALLS
   && !TARGET_GPWORD, jump tables will use absolute addresses, and should
   therefore not be included in the read-only part of a DSO.  Handle such
   cases by selecting a normal data section instead of a read-only one.
   The logic apes that in default_function_rodata_section.  */

static section *
mips_function_rodata_section (tree decl)
{
  if (!TARGET_ABICALLS || TARGET_GPWORD)
    return default_function_rodata_section (decl);

  if (decl && DECL_SECTION_NAME (decl))
    {
      const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
      if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
        {
          char *rname = ASTRDUP (name);
          rname[14] = 'd';
          return get_section (rname, SECTION_LINKONCE | SECTION_WRITE, decl);
        }
      else if (flag_function_sections && flag_data_sections
               && strncmp (name, ".text.", 6) == 0)
        {
          char *rname = ASTRDUP (name);
          memcpy (rname + 1, "data", 4);
          return get_section (rname, SECTION_WRITE, decl);
        }
    }
  return data_section;
}

/* Implement TARGET_IN_SMALL_DATA_P.  This function controls whether
   locally-defined objects go in a small data section.  It also controls
   the setting of the SYMBOL_REF_SMALL_P flag, which in turn helps
   mips_classify_symbol decide when to use %gp_rel(...)($gp) accesses.  */

static bool
mips_in_small_data_p (const_tree decl)
{
  HOST_WIDE_INT size;

  if (TREE_CODE (decl) == STRING_CST || TREE_CODE (decl) == FUNCTION_DECL)
    return false;

  /* We don't yet generate small-data references for -mabicalls or
     VxWorks RTP code.  See the related -G handling in override_options.  */
  if (TARGET_ABICALLS || TARGET_VXWORKS_RTP)
    return false;

  if (TREE_CODE (decl) == VAR_DECL && DECL_SECTION_NAME (decl) != 0)
    {
      const char *name;

      /* Reject anything that isn't in a known small-data section.  */
      name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
      if (strcmp (name, ".sdata") != 0 && strcmp (name, ".sbss") != 0)
        return false;

      /* If a symbol is defined externally, the assembler will use the
         usual -G rules when deciding how to implement macros.  */
      if (mips_lo_relocs[SYMBOL_GP_RELATIVE] || !DECL_EXTERNAL (decl))
        return true;
    }
  else if (TARGET_EMBEDDED_DATA)
    {
      /* Don't put constants into the small data section: we want them
         to be in ROM rather than RAM.  */
      if (TREE_CODE (decl) != VAR_DECL)
        return false;

      if (TREE_READONLY (decl)
          && !TREE_SIDE_EFFECTS (decl)
          && (!DECL_INITIAL (decl) || TREE_CONSTANT (DECL_INITIAL (decl))))
        return false;
    }

  /* Enforce -mlocal-sdata.  */
  if (!TARGET_LOCAL_SDATA && !TREE_PUBLIC (decl))
    return false;

  /* Enforce -mextern-sdata.  */
  if (!TARGET_EXTERN_SDATA && DECL_P (decl))
    {
      if (DECL_EXTERNAL (decl))
        return false;
      if (DECL_COMMON (decl) && DECL_INITIAL (decl) == NULL)
        return false;
    }

  size = int_size_in_bytes (TREE_TYPE (decl));
  return (size > 0 && size <= mips_section_threshold);
}

/* Implement TARGET_USE_ANCHORS_FOR_SYMBOL_P.  We don't want to use
   anchors for small data: the GP register acts as an anchor in that
   case.  We also don't want to use them for PC-relative accesses,
   where the PC acts as an anchor.  */

static bool
mips_use_anchors_for_symbol_p (const_rtx symbol)
{
  switch (mips_classify_symbol (symbol, SYMBOL_CONTEXT_MEM))
    {
    case SYMBOL_PC_RELATIVE:
    case SYMBOL_GP_RELATIVE:
      return false;

    default:
      return default_use_anchors_for_symbol_p (symbol);
    }
}
\f
/* The MIPS debug format wants all automatic variables and arguments
   to be in terms of the virtual frame pointer (stack pointer before
   any adjustment in the function), while the MIPS 3.0 linker wants
   the frame pointer to be the stack pointer after the initial
   adjustment.  So, we do the adjustment here.  The arg pointer (which
   is eliminated) points to the virtual frame pointer, while the frame
   pointer (which may be eliminated) points to the stack pointer after
   the initial adjustments.  */

HOST_WIDE_INT
mips_debugger_offset (rtx addr, HOST_WIDE_INT offset)
{
  rtx offset2 = const0_rtx;
  rtx reg = eliminate_constant_term (addr, &offset2);

  if (offset == 0)
    offset = INTVAL (offset2);

  if (reg == stack_pointer_rtx || reg == frame_pointer_rtx
      || reg == hard_frame_pointer_rtx)
    {
      offset -= cfun->machine->frame.total_size;
      if (reg == hard_frame_pointer_rtx)
        offset += cfun->machine->frame.hard_frame_pointer_offset;
    }

  /* sdbout_parms does not want this to crash for unrecognized cases.  */
#if 0
  else if (reg != arg_pointer_rtx)
    fatal_insn ("mips_debugger_offset called with non stack/frame/arg pointer",
                addr);
#endif

  return offset;
}
\f
/* When using assembler macros, keep track of all of small-data externs
   so that mips_file_end can emit the appropriate declarations for them.

   In most cases it would be safe (though pointless) to emit .externs
   for other symbols too.  One exception is when an object is within
   the -G limit but declared by the user to be in a section other
   than .sbss or .sdata.  */

void
mips_output_external (FILE *file, tree decl, const char *name)
{
  default_elf_asm_output_external (file, decl, name);

  /* We output the name if and only if TREE_SYMBOL_REFERENCED is
     set in order to avoid putting out names that are never really
     used. */
  if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
    {
      if (!TARGET_EXPLICIT_RELOCS && mips_in_small_data_p (decl))
        {
          fputs ("\t.extern\t", file);
          assemble_name (file, name);
          fprintf (file, ", " HOST_WIDE_INT_PRINT_DEC "\n",
                   int_size_in_bytes (TREE_TYPE (decl)));
        }
      else if (TARGET_IRIX
               && mips_abi == ABI_32
               && TREE_CODE (decl) == FUNCTION_DECL)
        {
          /* In IRIX 5 or IRIX 6 for the O32 ABI, we must output a
             `.global name .text' directive for every used but
             undefined function.  If we don't, the linker may perform
             an optimization (skipping over the insns that set $gp)
             when it is unsafe.  */
          fputs ("\t.globl ", file);
          assemble_name (file, name);
          fputs (" .text\n", file);
        }
    }
}
\f
/* Emit a new filename to a stream.  If we are smuggling stabs, try to
   put out a MIPS ECOFF file and a stab.  */

void
mips_output_filename (FILE *stream, const char *name)
{

  /* If we are emitting DWARF-2, let dwarf2out handle the ".file"
     directives.  */
  if (write_symbols == DWARF2_DEBUG)
    return;
  else if (mips_output_filename_first_time)
    {
      mips_output_filename_first_time = 0;
      num_source_filenames += 1;
      current_function_file = name;
      fprintf (stream, "\t.file\t%d ", num_source_filenames);
      output_quoted_string (stream, name);
      putc ('\n', stream);
    }

  /* If we are emitting stabs, let dbxout.c handle this (except for
     the mips_output_filename_first_time case).  */
  else if (write_symbols == DBX_DEBUG)
    return;

  else if (name != current_function_file
           && strcmp (name, current_function_file) != 0)
    {
      num_source_filenames += 1;
      current_function_file = name;
      fprintf (stream, "\t.file\t%d ", num_source_filenames);
      output_quoted_string (stream, name);
      putc ('\n', stream);
    }
}

/* MIPS implementation of TARGET_ASM_OUTPUT_DWARF_DTPREL.  */

static void
mips_output_dwarf_dtprel (FILE *file, int size, rtx x)
{
  switch (size)
    {
    case 4:
      fputs ("\t.dtprelword\t", file);
      break;

    case 8:
      fputs ("\t.dtpreldword\t", file);
      break;

    default:
      gcc_unreachable ();
    }
  output_addr_const (file, x);
  fputs ("+0x8000", file);
}

/* Implement TARGET_DWARF_REGISTER_SPAN.  */

static rtx
mips_dwarf_register_span (rtx reg)
{
  rtx high, low;
  enum machine_mode mode;

  /* By default, GCC maps increasing register numbers to increasing
     memory locations, but paired FPRs are always little-endian,
     regardless of the prevailing endianness.  */
  mode = GET_MODE (reg);
  if (FP_REG_P (REGNO (reg))
      && TARGET_BIG_ENDIAN
      && MAX_FPRS_PER_FMT > 1
      && GET_MODE_SIZE (mode) > UNITS_PER_FPREG)
    {
      gcc_assert (GET_MODE_SIZE (mode) == UNITS_PER_HWFPVALUE);
      high = mips_subword (reg, true);
      low = mips_subword (reg, false);
      return gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, high, low));
    }

  return NULL_RTX;
}
\f
/* Output an ASCII string, in a space-saving way.  PREFIX is the string
   that should be written before the opening quote, such as "\t.ascii\t"
   for real string data or "\t# " for a comment.  */

void
mips_output_ascii (FILE *stream, const char *string_param, size_t len,
                   const char *prefix)
{
  size_t i;
  int cur_pos = 17;
  register const unsigned char *string =
    (const unsigned char *)string_param;

  fprintf (stream, "%s\"", prefix);
  for (i = 0; i < len; i++)
    {
      register int c = string[i];

      if (ISPRINT (c))
        {
          if (c == '\\' || c == '\"')
            {
              putc ('\\', stream);
              cur_pos++;
            }
          putc (c, stream);
          cur_pos++;
        }
      else
        {
          fprintf (stream, "\\%03o", c);
          cur_pos += 4;
        }

      if (cur_pos > 72 && i+1 < len)
        {
          cur_pos = 17;
          fprintf (stream, "\"\n%s\"", prefix);
        }
    }
  fprintf (stream, "\"\n");
}

#ifdef BSS_SECTION_ASM_OP
/* Implement ASM_OUTPUT_ALIGNED_BSS.  This differs from the default only
   in the use of sbss.  */

void
mips_output_aligned_bss (FILE *stream, tree decl, const char *name,
                         unsigned HOST_WIDE_INT size, int align)
{
  extern tree last_assemble_variable_decl;

  if (mips_in_small_data_p (decl))
    switch_to_section (get_named_section (NULL, ".sbss", 0));
  else
    switch_to_section (bss_section);
  ASM_OUTPUT_ALIGN (stream, floor_log2 (align / BITS_PER_UNIT));
  last_assemble_variable_decl = decl;
  ASM_DECLARE_OBJECT_NAME (stream, name, decl);
  ASM_OUTPUT_SKIP (stream, size != 0 ? size : 1);
}
#endif
\f
/* Emit either a label, .comm, or .lcomm directive.  When using assembler
   macros, mark the symbol as written so that mips_file_end won't emit an
   .extern for it.  STREAM is the output file, NAME is the name of the
   symbol, INIT_STRING is the string that should be written before the
   symbol and FINAL_STRING is the string that should be written after it.
   FINAL_STRING is a printf() format that consumes the remaining arguments.  */

void
mips_declare_object (FILE *stream, const char *name, const char *init_string,
                     const char *final_string, ...)
{
  va_list ap;

  fputs (init_string, stream);
  assemble_name (stream, name);
  va_start (ap, final_string);
  vfprintf (stream, final_string, ap);
  va_end (ap);

  if (!TARGET_EXPLICIT_RELOCS)
    {
      tree name_tree = get_identifier (name);
      TREE_ASM_WRITTEN (name_tree) = 1;
    }
}

/* Declare a common object of SIZE bytes using asm directive INIT_STRING.
   NAME is the name of the object and ALIGN is the required alignment
   in bytes.  TAKES_ALIGNMENT_P is true if the directive takes a third
   alignment argument.  */

void
mips_declare_common_object (FILE *stream, const char *name,
                            const char *init_string,
                            unsigned HOST_WIDE_INT size,
                            unsigned int align, bool takes_alignment_p)
{
  if (!takes_alignment_p)
    {
      size += (align / BITS_PER_UNIT) - 1;
      size -= size % (align / BITS_PER_UNIT);
      mips_declare_object (stream, name, init_string,
                           "," HOST_WIDE_INT_PRINT_UNSIGNED "\n", size);
    }
  else
    mips_declare_object (stream, name, init_string,
                         "," HOST_WIDE_INT_PRINT_UNSIGNED ",%u\n",
                         size, align / BITS_PER_UNIT);
}

/* Implement ASM_OUTPUT_ALIGNED_DECL_COMMON.  This is usually the same as the
   elfos.h version, but we also need to handle -muninit-const-in-rodata.  */

void
mips_output_aligned_decl_common (FILE *stream, tree decl, const char *name,
                                 unsigned HOST_WIDE_INT size,
                                 unsigned int align)
{
  /* If the target wants uninitialized const declarations in
     .rdata then don't put them in .comm.  */
  if (TARGET_EMBEDDED_DATA && TARGET_UNINIT_CONST_IN_RODATA
      && TREE_CODE (decl) == VAR_DECL && TREE_READONLY (decl)
      && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
    {
      if (TREE_PUBLIC (decl) && DECL_NAME (decl))
        targetm.asm_out.globalize_label (stream, name);

      switch_to_section (readonly_data_section);
      ASM_OUTPUT_ALIGN (stream, floor_log2 (align / BITS_PER_UNIT));
      mips_declare_object (stream, name, "",
                           ":\n\t.space\t" HOST_WIDE_INT_PRINT_UNSIGNED "\n",
                           size);
    }
  else
    mips_declare_common_object (stream, name, "\n\t.comm\t",
                                size, align, true);
}

#ifdef ASM_OUTPUT_SIZE_DIRECTIVE
extern int size_directive_output;

/* Implement ASM_DECLARE_OBJECT_NAME.  This is like most of the standard ELF
   definitions except that it uses mips_declare_object() to emit the label.  */

void
mips_declare_object_name (FILE *stream, const char *name,
                          tree decl ATTRIBUTE_UNUSED)
{
#ifdef ASM_OUTPUT_TYPE_DIRECTIVE
  ASM_OUTPUT_TYPE_DIRECTIVE (stream, name, "object");
#endif

  size_directive_output = 0;
  if (!flag_inhibit_size_directive && DECL_SIZE (decl))
    {
      HOST_WIDE_INT size;

      size_directive_output = 1;
      size = int_size_in_bytes (TREE_TYPE (decl));
      ASM_OUTPUT_SIZE_DIRECTIVE (stream, name, size);
    }

  mips_declare_object (stream, name, "", ":\n");
}

/* Implement ASM_FINISH_DECLARE_OBJECT.  This is generic ELF stuff.  */

void
mips_finish_declare_object (FILE *stream, tree decl, int top_level, int at_end)
{
  const char *name;

  name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
  if (!flag_inhibit_size_directive
      && DECL_SIZE (decl) != 0
      && !at_end && top_level
      && DECL_INITIAL (decl) == error_mark_node
      && !size_directive_output)
    {
      HOST_WIDE_INT size;

      size_directive_output = 1;
      size = int_size_in_bytes (TREE_TYPE (decl));
      ASM_OUTPUT_SIZE_DIRECTIVE (stream, name, size);
    }
}
#endif
\f
/* Implement TARGET_ASM_FILE_START.  */

static void
mips_file_start (void)
{
  default_file_start ();

  if (!TARGET_IRIX)
    {
      /* Generate a special section to describe the ABI switches used to
         produce the resultant binary.  This used to be done by the assembler
         setting bits in the ELF header's flags field, but we have run out of
         bits.  GDB needs this information in order to be able to correctly
         debug these binaries.  See the function mips_gdbarch_init() in
         gdb/mips-tdep.c.  This is unnecessary for the IRIX 5/6 ABIs and
         causes unnecessary IRIX 6 ld warnings.  */
      const char * abi_string = NULL;

      switch (mips_abi)
        {
        case ABI_32:   abi_string = "abi32"; break;
        case ABI_N32:  abi_string = "abiN32"; break;
        case ABI_64:   abi_string = "abi64"; break;
        case ABI_O64:  abi_string = "abiO64"; break;
        case ABI_EABI: abi_string = TARGET_64BIT ? "eabi64" : "eabi32"; break;
        default:
          gcc_unreachable ();
        }
      /* Note - we use fprintf directly rather than calling switch_to_section
         because in this way we can avoid creating an allocated section.  We
         do not want this section to take up any space in the running
         executable.  */
      fprintf (asm_out_file, "\t.section .mdebug.%s\n\t.previous\n",
               abi_string);

      /* There is no ELF header flag to distinguish long32 forms of the
         EABI from long64 forms.  Emit a special section to help tools
         such as GDB.  Do the same for o64, which is sometimes used with
         -mlong64.  */
      if (mips_abi == ABI_EABI || mips_abi == ABI_O64)
        fprintf (asm_out_file, "\t.section .gcc_compiled_long%d\n"
                 "\t.previous\n", TARGET_LONG64 ? 64 : 32);

#ifdef HAVE_AS_GNU_ATTRIBUTE
      fprintf (asm_out_file, "\t.gnu_attribute 4, %d\n",
               TARGET_HARD_FLOAT_ABI ? (TARGET_DOUBLE_FLOAT ? 1 : 2) : 3);
#endif
    }

  /* Generate the pseudo ops that System V.4 wants.  */
  if (TARGET_ABICALLS)
    fprintf (asm_out_file, "\t.abicalls\n");

  if (flag_verbose_asm)
    fprintf (asm_out_file, "\n%s -G value = %d, Arch = %s, ISA = %d\n",
             ASM_COMMENT_START,
             mips_section_threshold, mips_arch_info->name, mips_isa);
}
\f
\f
/* Make the last instruction frame related and note that it performs
   the operation described by FRAME_PATTERN.  */

static void
mips_set_frame_expr (rtx frame_pattern)
{
  rtx insn;

  insn = get_last_insn ();
  RTX_FRAME_RELATED_P (insn) = 1;
  REG_NOTES (insn) = alloc_EXPR_LIST (REG_FRAME_RELATED_EXPR,
                                      frame_pattern,
                                      REG_NOTES (insn));
}


/* Return a frame-related rtx that stores REG at MEM.
   REG must be a single register.  */

static rtx
mips_frame_set (rtx mem, rtx reg)
{
  rtx set;

  /* If we're saving the return address register and the dwarf return
     address column differs from the hard register number, adjust the
     note reg to refer to the former.  */
  if (REGNO (reg) == GP_REG_FIRST + 31
      && DWARF_FRAME_RETURN_COLUMN != GP_REG_FIRST + 31)
    reg = gen_rtx_REG (GET_MODE (reg), DWARF_FRAME_RETURN_COLUMN);

  set = gen_rtx_SET (VOIDmode, mem, reg);
  RTX_FRAME_RELATED_P (set) = 1;

  return set;
}
\f
/* If a MIPS16e SAVE or RESTORE instruction saves or restores register
   mips16e_s2_s8_regs[X], it must also save the registers in indexes
   X + 1 onwards.  Likewise mips16e_a0_a3_regs.  */
static const unsigned char mips16e_s2_s8_regs[] = {
  30, 23, 22, 21, 20, 19, 18
};
static const unsigned char mips16e_a0_a3_regs[] = {
  4, 5, 6, 7
};

/* A list of the registers that can be saved by the MIPS16e SAVE instruction,
   ordered from the uppermost in memory to the lowest in memory.  */
static const unsigned char mips16e_save_restore_regs[] = {
  31, 30, 23, 22, 21, 20, 19, 18, 17, 16, 7, 6, 5, 4
};

/* Return the index of the lowest X in the range [0, SIZE) for which
   bit REGS[X] is set in MASK.  Return SIZE if there is no such X.  */

static unsigned int
mips16e_find_first_register (unsigned int mask, const unsigned char *regs,
                             unsigned int size)
{
  unsigned int i;

  for (i = 0; i < size; i++)
    if (BITSET_P (mask, regs[i]))
      break;

  return i;
}

/* *MASK_PTR is a mask of general-purpose registers and *NUM_REGS_PTR
   is the number of set bits.  If *MASK_PTR contains REGS[X] for some X
   in [0, SIZE), adjust *MASK_PTR and *NUM_REGS_PTR so that the same
   is true for all indexes (X, SIZE).  */

static void
mips16e_mask_registers (unsigned int *mask_ptr, const unsigned char *regs,
                        unsigned int size, unsigned int *num_regs_ptr)
{
  unsigned int i;

  i = mips16e_find_first_register (*mask_ptr, regs, size);
  for (i++; i < size; i++)
    if (!BITSET_P (*mask_ptr, regs[i]))
      {
        *num_regs_ptr += 1;
        *mask_ptr |= 1 << regs[i];
      }
}

/* Return a simplified form of X using the register values in REG_VALUES.
   REG_VALUES[R] is the last value assigned to hard register R, or null
   if R has not been modified.

   This function is rather limited, but is good enough for our purposes.  */

static rtx
mips16e_collect_propagate_value (rtx x, rtx *reg_values)
{
  rtx x0, x1;

  x = avoid_constant_pool_reference (x);

  if (UNARY_P (x))
    {
      x0 = mips16e_collect_propagate_value (XEXP (x, 0), reg_values);
      return simplify_gen_unary (GET_CODE (x), GET_MODE (x),
                                 x0, GET_MODE (XEXP (x, 0)));
    }

  if (ARITHMETIC_P (x))
    {
      x0 = mips16e_collect_propagate_value (XEXP (x, 0), reg_values);
      x1 = mips16e_collect_propagate_value (XEXP (x, 1), reg_values);
      return simplify_gen_binary (GET_CODE (x), GET_MODE (x), x0, x1);
    }

  if (REG_P (x)
      && reg_values[REGNO (x)]
      && !rtx_unstable_p (reg_values[REGNO (x)]))
    return reg_values[REGNO (x)];

  return x;
}

/* Return true if (set DEST SRC) stores an argument register into its
   caller-allocated save slot, storing the number of that argument
   register in *REGNO_PTR if so.  REG_VALUES is as for
   mips16e_collect_propagate_value.  */

static bool
mips16e_collect_argument_save_p (rtx dest, rtx src, rtx *reg_values,
                                 unsigned int *regno_ptr)
{
  unsigned int argno, regno;
  HOST_WIDE_INT offset, required_offset;
  rtx addr, base;

  /* Check that this is a word-mode store.  */
  if (!MEM_P (dest) || !REG_P (src) || GET_MODE (dest) != word_mode)
    return false;

  /* Check that the register being saved is an unmodified argument
     register.  */
  regno = REGNO (src);
  if (regno < GP_ARG_FIRST || regno > GP_ARG_LAST || reg_values[regno])
    return false;
  argno = regno - GP_ARG_FIRST;

  /* Check whether the address is an appropriate stack pointer or
     frame pointer access.  */
  addr = mips16e_collect_propagate_value (XEXP (dest, 0), reg_values);
  mips_split_plus (addr, &base, &offset);
  required_offset = cfun->machine->frame.total_size + argno * UNITS_PER_WORD;
  if (base == hard_frame_pointer_rtx)
    required_offset -= cfun->machine->frame.hard_frame_pointer_offset;
  else if (base != stack_pointer_rtx)
    return false;
  if (offset != required_offset)
    return false;

  *regno_ptr = regno;
  return true;
}

/* A subroutine of mips_expand_prologue, called only when generating
   MIPS16e SAVE instructions.  Search the start of the function for any
   instructions that save argument registers into their caller-allocated
   save slots.  Delete such instructions and return a value N such that
   saving [GP_ARG_FIRST, GP_ARG_FIRST + N) would make all the deleted
   instructions redundant.  */

static unsigned int
mips16e_collect_argument_saves (void)
{
  rtx reg_values[FIRST_PSEUDO_REGISTER];
  rtx insn, next, set, dest, src;
  unsigned int nargs, regno;

  push_topmost_sequence ();
  nargs = 0;
  memset (reg_values, 0, sizeof (reg_values));
  for (insn = get_insns (); insn; insn = next)
    {
      next = NEXT_INSN (insn);
      if (NOTE_P (insn))
        continue;

      if (!INSN_P (insn))
        break;

      set = PATTERN (insn);
      if (GET_CODE (set) != SET)
        break;

      dest = SET_DEST (set);
      src = SET_SRC (set);
      if (mips16e_collect_argument_save_p (dest, src, reg_values, &regno))
        {
          if (!BITSET_P (cfun->machine->frame.mask, regno))
            {
              delete_insn (insn);
              nargs = MAX (nargs, (regno - GP_ARG_FIRST) + 1);
            }
        }
      else if (REG_P (dest) && GET_MODE (dest) == word_mode)
        reg_values[REGNO (dest)]
          = mips16e_collect_propagate_value (src, reg_values);
      else
        break;
    }
  pop_topmost_sequence ();

  return nargs;
}

/* Return a move between register REGNO and memory location SP + OFFSET.
   Make the move a load if RESTORE_P, otherwise make it a frame-related
   store.  */

static rtx
mips16e_save_restore_reg (bool restore_p, HOST_WIDE_INT offset,
                          unsigned int regno)
{
  rtx reg, mem;

  mem = gen_frame_mem (SImode, plus_constant (stack_pointer_rtx, offset));
  reg = gen_rtx_REG (SImode, regno);
  return (restore_p
          ? gen_rtx_SET (VOIDmode, reg, mem)
          : mips_frame_set (mem, reg));
}

/* Return RTL for a MIPS16e SAVE or RESTORE instruction; RESTORE_P says which.
   The instruction must:

     - Allocate or deallocate SIZE bytes in total; SIZE is known
       to be nonzero.

     - Save or restore as many registers in *MASK_PTR as possible.
       The instruction saves the first registers at the top of the
       allocated area, with the other registers below it.

     - Save NARGS argument registers above the allocated area.

   (NARGS is always zero if RESTORE_P.)

   The SAVE and RESTORE instructions cannot save and restore all general
   registers, so there may be some registers left over for the caller to
   handle.  Destructively modify *MASK_PTR so that it contains the registers
   that still need to be saved or restored.  The caller can save these
   registers in the memory immediately below *OFFSET_PTR, which is a
   byte offset from the bottom of the allocated stack area.  */

static rtx
mips16e_build_save_restore (bool restore_p, unsigned int *mask_ptr,
                            HOST_WIDE_INT *offset_ptr, unsigned int nargs,
                            HOST_WIDE_INT size)
{
  rtx pattern, set;
  HOST_WIDE_INT offset, top_offset;
  unsigned int i, regno;
  int n;

  gcc_assert (cfun->machine->frame.num_fp == 0);

  /* Calculate the number of elements in the PARALLEL.  We need one element
     for the stack adjustment, one for each argument register save, and one
     for each additional register move.  */
  n = 1 + nargs;
  for (i = 0; i < ARRAY_SIZE (mips16e_save_restore_regs); i++)
    if (BITSET_P (*mask_ptr, mips16e_save_restore_regs[i]))
      n++;

  /* Create the final PARALLEL.  */
  pattern = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (n));
  n = 0;

  /* Add the stack pointer adjustment.  */
  set = gen_rtx_SET (VOIDmode, stack_pointer_rtx,
                     plus_constant (stack_pointer_rtx,
                                    restore_p ? size : -size));
  RTX_FRAME_RELATED_P (set) = 1;
  XVECEXP (pattern, 0, n++) = set;

  /* Stack offsets in the PARALLEL are relative to the old stack pointer.  */
  top_offset = restore_p ? size : 0;

  /* Save the arguments.  */
  for (i = 0; i < nargs; i++)
    {
      offset = top_offset + i * GET_MODE_SIZE (gpr_mode);
      set = mips16e_save_restore_reg (restore_p, offset, GP_ARG_FIRST + i);
      XVECEXP (pattern, 0, n++) = set;
    }

  /* Then fill in the other register moves.  */
  offset = top_offset;
  for (i = 0; i < ARRAY_SIZE (mips16e_save_restore_regs); i++)
    {
      regno = mips16e_save_restore_regs[i];
      if (BITSET_P (*mask_ptr, regno))
        {
          offset -= UNITS_PER_WORD;
          set = mips16e_save_restore_reg (restore_p, offset, regno);
          XVECEXP (pattern, 0, n++) = set;
          *mask_ptr &= ~(1 << regno);
        }
    }

  /* Tell the caller what offset it should use for the remaining registers.  */
  *offset_ptr = size + (offset - top_offset) + size;

  gcc_assert (n == XVECLEN (pattern, 0));

  return pattern;
}

/* PATTERN is a PARALLEL whose first element adds ADJUST to the stack
   pointer.  Return true if PATTERN matches the kind of instruction
   generated by mips16e_build_save_restore.  If INFO is nonnull,
   initialize it when returning true.  */

bool
mips16e_save_restore_pattern_p (rtx pattern, HOST_WIDE_INT adjust,
                                struct mips16e_save_restore_info *info)
{
  unsigned int i, nargs, mask, extra;
  HOST_WIDE_INT top_offset, save_offset, offset;
  rtx set, reg, mem, base;
  int n;

  if (!GENERATE_MIPS16E_SAVE_RESTORE)
    return false;

  /* Stack offsets in the PARALLEL are relative to the old stack pointer.  */
  top_offset = adjust > 0 ? adjust : 0;

  /* Interpret all other members of the PARALLEL.  */
  save_offset = top_offset - GET_MODE_SIZE (gpr_mode);
  mask = 0;
  nargs = 0;
  i = 0;
  for (n = 1; n < XVECLEN (pattern, 0); n++)
    {
      /* Check that we have a SET.  */
      set = XVECEXP (pattern, 0, n);
      if (GET_CODE (set) != SET)
        return false;

      /* Check that the SET is a load (if restoring) or a store
         (if saving).  */
      mem = adjust > 0 ? SET_SRC (set) : SET_DEST (set);
      if (!MEM_P (mem))
        return false;

      /* Check that the address is the sum of the stack pointer and a
         possibly-zero constant offset.  */
      mips_split_plus (XEXP (mem, 0), &base, &offset);
      if (base != stack_pointer_rtx)
        return false;

      /* Check that SET's other operand is a register.  */
      reg = adjust > 0 ? SET_DEST (set) : SET_SRC (set);
      if (!REG_P (reg))
        return false;

      /* Check for argument saves.  */
      if (offset == top_offset + nargs * GET_MODE_SIZE (gpr_mode)
          && REGNO (reg) == GP_ARG_FIRST + nargs)
        nargs++;
      else if (offset == save_offset)
        {
          while (mips16e_save_restore_regs[i++] != REGNO (reg))
            if (i == ARRAY_SIZE (mips16e_save_restore_regs))
              return false;

          mask |= 1 << REGNO (reg);
          save_offset -= GET_MODE_SIZE (gpr_mode);
        }
      else
        return false;
    }

  /* Check that the restrictions on register ranges are met.  */
  extra = 0;
  mips16e_mask_registers (&mask, mips16e_s2_s8_regs,
                          ARRAY_SIZE (mips16e_s2_s8_regs), &extra);
  mips16e_mask_registers (&mask, mips16e_a0_a3_regs,
                          ARRAY_SIZE (mips16e_a0_a3_regs), &extra);
  if (extra != 0)
    return false;

  /* Make sure that the topmost argument register is not saved twice.
     The checks above ensure that the same is then true for the other
     argument registers.  */
  if (nargs > 0 && BITSET_P (mask, GP_ARG_FIRST + nargs - 1))
    return false;

  /* Pass back information, if requested.  */
  if (info)
    {
      info->nargs = nargs;
      info->mask = mask;
      info->size = (adjust > 0 ? adjust : -adjust);
    }

  return true;
}

/* Add a MIPS16e SAVE or RESTORE register-range argument to string S
   for the register range [MIN_REG, MAX_REG].  Return a pointer to
   the null terminator.  */

static char *
mips16e_add_register_range (char *s, unsigned int min_reg,
                            unsigned int max_reg)
{
  if (min_reg != max_reg)
    s += sprintf (s, ",%s-%s", reg_names[min_reg], reg_names[max_reg]);
  else
    s += sprintf (s, ",%s", reg_names[min_reg]);
  return s;
}

/* Return the assembly instruction for a MIPS16e SAVE or RESTORE instruction.
   PATTERN and ADJUST are as for mips16e_save_restore_pattern_p.  */

const char *
mips16e_output_save_restore (rtx pattern, HOST_WIDE_INT adjust)
{
  static char buffer[300];

  struct mips16e_save_restore_info info;
  unsigned int i, end;
  char *s;

  /* Parse the pattern.  */
  if (!mips16e_save_restore_pattern_p (pattern, adjust, &info))
    gcc_unreachable ();

  /* Add the mnemonic.  */
  s = strcpy (buffer, adjust > 0 ? "restore\t" : "save\t");
  s += strlen (s);

  /* Save the arguments.  */
  if (info.nargs > 1)
    s += sprintf (s, "%s-%s,", reg_names[GP_ARG_FIRST],
                  reg_names[GP_ARG_FIRST + info.nargs - 1]);
  else if (info.nargs == 1)
    s += sprintf (s, "%s,", reg_names[GP_ARG_FIRST]);

  /* Emit the amount of stack space to allocate or deallocate.  */
  s += sprintf (s, "%d", (int) info.size);

  /* Save or restore $16.  */
  if (BITSET_P (info.mask, 16))
    s += sprintf (s, ",%s", reg_names[GP_REG_FIRST + 16]);

  /* Save or restore $17.  */
  if (BITSET_P (info.mask, 17))
    s += sprintf (s, ",%s", reg_names[GP_REG_FIRST + 17]);

  /* Save or restore registers in the range $s2...$s8, which
     mips16e_s2_s8_regs lists in decreasing order.  Note that this
     is a software register range; the hardware registers are not
     numbered consecutively.  */
  end = ARRAY_SIZE (mips16e_s2_s8_regs);
  i = mips16e_find_first_register (info.mask, mips16e_s2_s8_regs, end);
  if (i < end)
    s = mips16e_add_register_range (s, mips16e_s2_s8_regs[end - 1],
                                    mips16e_s2_s8_regs[i]);

  /* Save or restore registers in the range $a0...$a3.  */
  end = ARRAY_SIZE (mips16e_a0_a3_regs);
  i = mips16e_find_first_register (info.mask, mips16e_a0_a3_regs, end);
  if (i < end)
    s = mips16e_add_register_range (s, mips16e_a0_a3_regs[i],
                                    mips16e_a0_a3_regs[end - 1]);

  /* Save or restore $31.  */
  if (BITSET_P (info.mask, 31))
    s += sprintf (s, ",%s", reg_names[GP_REG_FIRST + 31]);

  return buffer;
}
\f
/* Return true if the current function has an insn that implicitly
   refers to $gp.  */

static bool
mips_function_has_gp_insn (void)
{
  /* Don't bother rechecking if we found one last time.  */
  if (!cfun->machine->has_gp_insn_p)
    {
      rtx insn;

      push_topmost_sequence ();
      for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
        if (INSN_P (insn)
            && GET_CODE (PATTERN (insn)) != USE
            && GET_CODE (PATTERN (insn)) != CLOBBER
            && (get_attr_got (insn) != GOT_UNSET
                || small_data_pattern (PATTERN (insn), VOIDmode)))
          break;
      pop_topmost_sequence ();

      cfun->machine->has_gp_insn_p = (insn != 0);
    }
  return cfun->machine->has_gp_insn_p;
}


/* Return the register that should be used as the global pointer
   within this function.  Return 0 if the function doesn't need
   a global pointer.  */

static unsigned int
mips_global_pointer (void)
{
  unsigned int regno;

  /* $gp is always available unless we're using a GOT.  */
  if (!TARGET_USE_GOT)
    return GLOBAL_POINTER_REGNUM;

  /* We must always provide $gp when it is used implicitly.  */
  if (!TARGET_EXPLICIT_RELOCS)
    return GLOBAL_POINTER_REGNUM;

  /* FUNCTION_PROFILER includes a jal macro, so we need to give it
     a valid gp.  */
  if (current_function_profile)
    return GLOBAL_POINTER_REGNUM;

  /* If the function has a nonlocal goto, $gp must hold the correct
     global pointer for the target function.  */
  if (current_function_has_nonlocal_goto)
    return GLOBAL_POINTER_REGNUM;

  /* If the gp is never referenced, there's no need to initialize it.
     Note that reload can sometimes introduce constant pool references
     into a function that otherwise didn't need them.  For example,
     suppose we have an instruction like:

          (set (reg:DF R1) (float:DF (reg:SI R2)))

     If R2 turns out to be constant such as 1, the instruction may have a
     REG_EQUAL note saying that R1 == 1.0.  Reload then has the option of
     using this constant if R2 doesn't get allocated to a register.

     In cases like these, reload will have added the constant to the pool
     but no instruction will yet refer to it.  */
  if (!df_regs_ever_live_p (GLOBAL_POINTER_REGNUM)
      && !current_function_uses_const_pool
      && !mips_function_has_gp_insn ())
    return 0;

  /* We need a global pointer, but perhaps we can use a call-clobbered
     register instead of $gp.  */
  if (TARGET_CALL_SAVED_GP && current_function_is_leaf)
    for (regno = GP_REG_FIRST; regno <= GP_REG_LAST; regno++)
      if (!df_regs_ever_live_p (regno)
          && call_really_used_regs[regno]
          && !fixed_regs[regno]
          && regno != PIC_FUNCTION_ADDR_REGNUM)
        return regno;

  return GLOBAL_POINTER_REGNUM;
}

/* Return true if the current function returns its value in a floating-point
   register in MIPS16 mode.  */

static bool
mips16_cfun_returns_in_fpr_p (void)
{
  tree return_type = DECL_RESULT (current_function_decl);
  return (TARGET_MIPS16
          && TARGET_HARD_FLOAT_ABI
          && !aggregate_value_p (return_type, current_function_decl)
          && mips_return_mode_in_fpr_p (DECL_MODE (return_type)));
}


/* Return true if the current function must save REGNO.  */

static bool
mips_save_reg_p (unsigned int regno)
{
  /* We only need to save $gp if TARGET_CALL_SAVED_GP and only then
     if we have not chosen a call-clobbered substitute.  */
  if (regno == GLOBAL_POINTER_REGNUM)
    return TARGET_CALL_SAVED_GP && cfun->machine->global_pointer == regno;

  /* Check call-saved registers.  */
  if ((current_function_saves_all_registers || df_regs_ever_live_p (regno))
      && !call_really_used_regs[regno])
    return true;

  /* Save both registers in an FPR pair if either one is used.  This is
     needed for the case when MIN_FPRS_PER_FMT == 1, which allows the odd
     register to be used without the even register.  */
  if (FP_REG_P (regno)
      && MAX_FPRS_PER_FMT == 2
      && df_regs_ever_live_p (regno + 1)
      && !call_really_used_regs[regno + 1])
    return true;

  /* We need to save the old frame pointer before setting up a new one.  */
  if (regno == HARD_FRAME_POINTER_REGNUM && frame_pointer_needed)
    return true;

  /* Check for registers that must be saved for FUNCTION_PROFILER.  */
  if (current_function_profile && MIPS_SAVE_REG_FOR_PROFILING_P (regno))
    return true;

  /* We need to save the incoming return address if it is ever clobbered
     within the function, if __builtin_eh_return is being used to set a
     different return address, or if a stub is being used to return a
     value in FPRs.  */
  if (regno == GP_REG_FIRST + 31
      && (df_regs_ever_live_p (regno)
          || current_function_calls_eh_return
          || mips16_cfun_returns_in_fpr_p ()))
    return true;

  return false;
}

/* Populate the current function's mips_frame_info structure.

   MIPS stack frames look like:

        +-------------------------------+
        |                               |
        |  incoming stack arguments     |
        |                               |
        +-------------------------------+
        |                               |
        |  caller-allocated save area   |
      A |  for register arguments       |
        |                               |
        +-------------------------------+ <-- incoming stack pointer
        |                               |
        |  callee-allocated save area   |
      B |  for arguments that are       |
        |  split between registers and  |
        |  the stack                    |
        |                               |
        +-------------------------------+ <-- arg_pointer_rtx
        |                               |
      C |  callee-allocated save area   |
        |  for register varargs         |
        |                               |
        +-------------------------------+ <-- frame_pointer_rtx + fp_sp_offset
        |                               |       + UNITS_PER_HWFPVALUE
        |  FPR save area                |
        |                               |
        +-------------------------------+ <-- frame_pointer_rtx + gp_sp_offset
        |                               |       + UNITS_PER_WORD
        |  GPR save area                |
        |                               |
        +-------------------------------+
        |                               | \
        |  local variables              |  | var_size
        |                               | /
        +-------------------------------+
        |                               | \
        |  $gp save area                |  | cprestore_size
        |                               | /
      P +-------------------------------+ <-- hard_frame_pointer_rtx for
        |                               |       MIPS16 code
        |  outgoing stack arguments     |
        |                               |
        +-------------------------------+
        |                               |
        |  caller-allocated save area   |
        |  for register arguments       |
        |                               |
        +-------------------------------+ <-- stack_pointer_rtx
                                              frame_pointer_rtx
                                              hard_frame_pointer_rtx for
                                                non-MIPS16 code.

   At least two of A, B and C will be empty.

   Dynamic stack allocations such as alloca insert data at point P.
   They decrease stack_pointer_rtx but leave frame_pointer_rtx and
   hard_frame_pointer_rtx unchanged.  */

static void
mips_compute_frame_info (void)
{
  struct mips_frame_info *frame;
  HOST_WIDE_INT offset, size;
  unsigned int regno, i;

  frame = &cfun->machine->frame;
  memset (frame, 0, sizeof (*frame));
  size = get_frame_size ();

  cfun->machine->global_pointer = mips_global_pointer ();

  /* The first STARTING_FRAME_OFFSET bytes contain the outgoing argument
     area and the $gp save slot.  This area isn't needed in leaf functions,
     but if the target-independent frame size is nonzero, we're committed
     to allocating it anyway.  */
  if (size == 0 && current_function_is_leaf)
    {
      /* The MIPS 3.0 linker does not like functions that dynamically
         allocate the stack and have 0 for STACK_DYNAMIC_OFFSET, since it
         looks like we are trying to create a second frame pointer to the
         function, so allocate some stack space to make it happy.  */
      if (current_function_calls_alloca)
        frame->args_size = REG_PARM_STACK_SPACE (cfun->decl);
      else
        frame->args_size = 0;
      frame->cprestore_size = 0;
    }
  else
    {
      frame->args_size = current_function_outgoing_args_size;
      frame->cprestore_size = STARTING_FRAME_OFFSET - frame->args_size;
    }
  offset = frame->args_size + frame->cprestore_size;

  /* Move above the local variables.  */
  frame->var_size = MIPS_STACK_ALIGN (size);
  offset += frame->var_size;

  /* Find out which GPRs we need to save.  */
  for (regno = GP_REG_FIRST; regno <= GP_REG_LAST; regno++)
    if (mips_save_reg_p (regno))
      {
        frame->num_gp++;
        frame->mask |= 1 << (regno - GP_REG_FIRST);
      }

  /* If this function calls eh_return, we must also save and restore the
     EH data registers.  */
  if (current_function_calls_eh_return)
    for (i = 0; EH_RETURN_DATA_REGNO (i) != INVALID_REGNUM; i++)
      {
        frame->num_gp++;
        frame->mask |= 1 << (EH_RETURN_DATA_REGNO (i) - GP_REG_FIRST);
      }

  /* The MIPS16e SAVE and RESTORE instructions have two ranges of registers:
     $a3-$a0 and $s2-$s8.  If we save one register in the range, we must
     save all later registers too.  */
  if (GENERATE_MIPS16E_SAVE_RESTORE)
    {
      mips16e_mask_registers (&frame->mask, mips16e_s2_s8_regs,
                              ARRAY_SIZE (mips16e_s2_s8_regs), &frame->num_gp);
      mips16e_mask_registers (&frame->mask, mips16e_a0_a3_regs,
                              ARRAY_SIZE (mips16e_a0_a3_regs), &frame->num_gp);
    }

  /* Move above the GPR save area.  */
  if (frame->num_gp > 0)
    {
      offset += MIPS_STACK_ALIGN (frame->num_gp * UNITS_PER_WORD);
      frame->gp_sp_offset = offset - UNITS_PER_WORD;
    }

  /* Find out which FPRs we need to save.  This loop must iterate over
     the same space as its companion in mips_for_each_saved_reg.  */
  if (TARGET_HARD_FLOAT)
    for (regno = FP_REG_FIRST; regno <= FP_REG_LAST; regno += MAX_FPRS_PER_FMT)
      if (mips_save_reg_p (regno))
        {
          frame->num_fp += MAX_FPRS_PER_FMT;
          frame->fmask |= ~(~0 << MAX_FPRS_PER_FMT) << (regno - FP_REG_FIRST);
        }

  /* Move above the FPR save area.  */
  if (frame->num_fp > 0)
    {
      offset += MIPS_STACK_ALIGN (frame->num_fp * UNITS_PER_FPREG);
      frame->fp_sp_offset = offset - UNITS_PER_HWFPVALUE;
    }

  /* Move above the callee-allocated varargs save area.  */
  offset += MIPS_STACK_ALIGN (cfun->machine->varargs_size);
  frame->arg_pointer_offset = offset;

  /* Move above the callee-allocated area for pretend stack arguments.  */
  offset += current_function_pretend_args_size;
  frame->total_size = offset;

  /* Work out the offsets of the save areas from the top of the frame.  */
  if (frame->gp_sp_offset > 0)
    frame->gp_save_offset = frame->gp_sp_offset - offset;
  if (frame->fp_sp_offset > 0)
    frame->fp_save_offset = frame->fp_sp_offset - offset;

  /* MIPS16 code offsets the frame pointer by the size of the outgoing
     arguments.  This tends to increase the chances of using unextended
     instructions for local variables and incoming arguments.  */
  if (TARGET_MIPS16)
    frame->hard_frame_pointer_offset = frame->args_size;
}

/* Return the style of GP load sequence that is being used for the
   current function.  */

enum mips_loadgp_style
mips_current_loadgp_style (void)
{
  if (!TARGET_USE_GOT || cfun->machine->global_pointer == 0)
    return LOADGP_NONE;

  if (TARGET_RTP_PIC)
    return LOADGP_RTP;

  if (TARGET_ABSOLUTE_ABICALLS)
    return LOADGP_ABSOLUTE;

  return TARGET_NEWABI ? LOADGP_NEWABI : LOADGP_OLDABI;
}
\f
/* Implement FRAME_POINTER_REQUIRED.  */

bool
mips_frame_pointer_required (void)
{
  /* If the function contains dynamic stack allocations, we need to
     use the frame pointer to access the static parts of the frame.  */
  if (current_function_calls_alloca)
    return true;

  /* In MIPS16 mode, we need a frame pointer for a large frame; otherwise,
     reload may be unable to compute the address of a local variable,
     since there is no way to add a large constant to the stack pointer
     without using a second temporary register.  */
  if (TARGET_MIPS16)
    {
      mips_compute_frame_info ();
      if (!SMALL_OPERAND (cfun->machine->frame.total_size))
        return true;
    }

  return false;
}

/* Implement INITIAL_ELIMINATION_OFFSET.  FROM is either the frame
   pointer or argument pointer.  TO is either the stack pointer or
   hard frame pointer.  */

HOST_WIDE_INT
mips_initial_elimination_offset (int from, int to)
{
  HOST_WIDE_INT offset;

  mips_compute_frame_info ();

  /* Set OFFSET to the offset from the soft frame pointer, which is also
     the offset from the end-of-prologue stack pointer.  */
  switch (from)
    {
    case FRAME_POINTER_REGNUM:
      offset = 0;
      break;

    case ARG_POINTER_REGNUM:
      offset = cfun->machine->frame.arg_pointer_offset;
      break;

    default:
      gcc_unreachable ();
    }

  if (to == HARD_FRAME_POINTER_REGNUM)
    offset -= cfun->machine->frame.hard_frame_pointer_offset;

  return offset;
}
\f
/* Implement TARGET_EXTRA_LIVE_ON_ENTRY.  Some code models use the incoming
   value of PIC_FUNCTION_ADDR_REGNUM to set up the global pointer.  */

static void
mips_extra_live_on_entry (bitmap regs)
{
  if (TARGET_USE_GOT && !TARGET_ABSOLUTE_ABICALLS)
    bitmap_set_bit (regs, PIC_FUNCTION_ADDR_REGNUM);
}

/* Implement RETURN_ADDR_RTX.  Note, we do not support moving
   back to a previous frame.  */

rtx
mips_return_addr (int count, rtx frame ATTRIBUTE_UNUSED)
{
  if (count != 0)
    return const0_rtx;

  return get_hard_reg_initial_val (Pmode, GP_REG_FIRST + 31);
}

/* Emit code to change the current function's return address to
   ADDRESS.  SCRATCH is available as a scratch register, if needed.
   ADDRESS and SCRATCH are both word-mode GPRs.  */

void
mips_set_return_address (rtx address, rtx scratch)
{
  rtx slot_address;

  gcc_assert ((cfun->machine->frame.mask >> 31) & 1);
  slot_address = mips_add_offset (scratch, stack_pointer_rtx,
                                  cfun->machine->frame.gp_sp_offset);

  mips_emit_move (gen_rtx_MEM (GET_MODE (address), slot_address), address);
}

/* Restore $gp from its save slot.  Valid only when using o32 or
   o64 abicalls.  */

void
mips_restore_gp (void)
{
  rtx address, slot;

  gcc_assert (TARGET_ABICALLS && TARGET_OLDABI);

  address = mips_add_offset (pic_offset_table_rtx,
                             frame_pointer_needed
                             ? hard_frame_pointer_rtx
                             : stack_pointer_rtx,
                             current_function_outgoing_args_size);
  slot = gen_rtx_MEM (Pmode, address);

  mips_emit_move (pic_offset_table_rtx, slot);
  if (!TARGET_EXPLICIT_RELOCS)
    emit_insn (gen_blockage ());
}
\f
/* A function to save or store a register.  The first argument is the
   register and the second is the stack slot.  */
typedef void (*mips_save_restore_fn) (rtx, rtx);

/* Use FN to save or restore register REGNO.  MODE is the register's
   mode and OFFSET is the offset of its save slot from the current
   stack pointer.  */

static void
mips_save_restore_reg (enum machine_mode mode, int regno,
                       HOST_WIDE_INT offset, mips_save_restore_fn fn)
{
  rtx mem;

  mem = gen_frame_mem (mode, plus_constant (stack_pointer_rtx, offset));

  fn (gen_rtx_REG (mode, regno), mem);
}


/* Call FN for each register that is saved by the current function.
   SP_OFFSET is the offset of the current stack pointer from the start
   of the frame.  */

static void
mips_for_each_saved_reg (HOST_WIDE_INT sp_offset, mips_save_restore_fn fn)
{
  enum machine_mode fpr_mode;
  HOST_WIDE_INT offset;
  int regno;

  /* Save registers starting from high to low.  The debuggers prefer at least
     the return register be stored at func+4, and also it allows us not to
     need a nop in the epilogue if at least one register is reloaded in
     addition to return address.  */
  offset = cfun->machine->frame.gp_sp_offset - sp_offset;
  for (regno = GP_REG_LAST; regno >= GP_REG_FIRST; regno--)
    if (BITSET_P (cfun->machine->frame.mask, regno - GP_REG_FIRST))
      {
        mips_save_restore_reg (gpr_mode, regno, offset, fn);
        offset -= GET_MODE_SIZE (gpr_mode);
      }

  /* This loop must iterate over the same space as its companion in
     mips_compute_frame_info.  */
  offset = cfun->machine->frame.fp_sp_offset - sp_offset;
  fpr_mode = (TARGET_SINGLE_FLOAT ? SFmode : DFmode);
  for (regno = (FP_REG_LAST - MAX_FPRS_PER_FMT + 1);
       regno >= FP_REG_FIRST;
       regno -= MAX_FPRS_PER_FMT)
    if (BITSET_P (cfun->machine->frame.fmask, regno - FP_REG_FIRST))
      {
        mips_save_restore_reg (fpr_mode, regno, offset, fn);
        offset -= GET_MODE_SIZE (fpr_mode);
      }
}
\f
/* If we're generating n32 or n64 abicalls, and the current function
   does not use $28 as its global pointer, emit a cplocal directive.
   Use pic_offset_table_rtx as the argument to the directive.  */

static void
mips_output_cplocal (void)
{
  if (!TARGET_EXPLICIT_RELOCS
      && cfun->machine->global_pointer > 0
      && cfun->machine->global_pointer != GLOBAL_POINTER_REGNUM)
    output_asm_insn (".cplocal %+", 0);
}

/* Set up the stack and frame (if desired) for the function.  */

static void
mips_output_function_prologue (FILE *file, HOST_WIDE_INT size ATTRIBUTE_UNUSED)
{
  const char *fnname;
  HOST_WIDE_INT tsize = cfun->machine->frame.total_size;

#ifdef SDB_DEBUGGING_INFO
  if (debug_info_level != DINFO_LEVEL_TERSE && write_symbols == SDB_DEBUG)
    SDB_OUTPUT_SOURCE_LINE (file, DECL_SOURCE_LINE (current_function_decl));
#endif

  /* In mips16 mode, we may need to generate a 32 bit to handle
     floating point arguments.  The linker will arrange for any 32-bit
     functions to call this stub, which will then jump to the 16-bit
     function proper.  */
  if (TARGET_MIPS16
      && TARGET_HARD_FLOAT_ABI
      && current_function_args_info.fp_code != 0)
    build_mips16_function_stub (file);

  /* Select the mips16 mode for this function.  */
  if (TARGET_MIPS16)
    fprintf (file, "\t.set\tmips16\n");
  else
    fprintf (file, "\t.set\tnomips16\n");

  if (!FUNCTION_NAME_ALREADY_DECLARED)
    {
      /* Get the function name the same way that toplev.c does before calling
         assemble_start_function.  This is needed so that the name used here
         exactly matches the name used in ASM_DECLARE_FUNCTION_NAME.  */
      fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);

      if (!flag_inhibit_size_directive)
        {
          fputs ("\t.ent\t", file);
          assemble_name (file, fnname);
          fputs ("\n", file);
        }

      assemble_name (file, fnname);
      fputs (":\n", file);
    }

  /* Stop mips_file_end from treating this function as external.  */
  if (TARGET_IRIX && mips_abi == ABI_32)
    TREE_ASM_WRITTEN (DECL_NAME (cfun->decl)) = 1;

  if (!flag_inhibit_size_directive)
    {
      /* .frame FRAMEREG, FRAMESIZE, RETREG */
      fprintf (file,
               "\t.frame\t%s," HOST_WIDE_INT_PRINT_DEC ",%s\t\t"
               "# vars= " HOST_WIDE_INT_PRINT_DEC ", regs= %d/%d"
               ", args= " HOST_WIDE_INT_PRINT_DEC
               ", gp= " HOST_WIDE_INT_PRINT_DEC "\n",
               (reg_names[(frame_pointer_needed)
                          ? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM]),
               (frame_pointer_needed
                ? tsize - cfun->machine->frame.hard_frame_pointer_offset
                : tsize),
               reg_names[GP_REG_FIRST + 31],
               cfun->machine->frame.var_size,
               cfun->machine->frame.num_gp,
               cfun->machine->frame.num_fp,
               cfun->machine->frame.args_size,
               cfun->machine->frame.cprestore_size);

      /* .mask MASK, GPOFFSET; .fmask FPOFFSET */
      fprintf (file, "\t.mask\t0x%08x," HOST_WIDE_INT_PRINT_DEC "\n",
               cfun->machine->frame.mask,
               cfun->machine->frame.gp_save_offset);
      fprintf (file, "\t.fmask\t0x%08x," HOST_WIDE_INT_PRINT_DEC "\n",
               cfun->machine->frame.fmask,
               cfun->machine->frame.fp_save_offset);

      /* Require:
         OLD_SP == *FRAMEREG + FRAMESIZE => can find old_sp from nominated FP reg.
         HIGHEST_GP_SAVED == *FRAMEREG + FRAMESIZE + GPOFFSET => can find saved regs.  */
    }

  if (mips_current_loadgp_style () == LOADGP_OLDABI)
    {
      /* Handle the initialization of $gp for SVR4 PIC.  */
      if (!cfun->machine->all_noreorder_p)
        output_asm_insn ("%(.cpload\t%^%)", 0);
      else
        output_asm_insn ("%(.cpload\t%^\n\t%<", 0);
    }
  else if (cfun->machine->all_noreorder_p)
    output_asm_insn ("%(%<", 0);

  /* Tell the assembler which register we're using as the global
     pointer.  This is needed for thunks, since they can use either
     explicit relocs or assembler macros.  */
  mips_output_cplocal ();
}

/* Do any necessary cleanup after a function to restore stack, frame,
   and regs.  */

#define RA_MASK BITMASK_HIGH    /* 1 << 31 */

static void
mips_output_function_epilogue (FILE *file ATTRIBUTE_UNUSED,
                               HOST_WIDE_INT size ATTRIBUTE_UNUSED)
{
  /* Reinstate the normal $gp.  */
  SET_REGNO (pic_offset_table_rtx, GLOBAL_POINTER_REGNUM);
  mips_output_cplocal ();

  if (cfun->machine->all_noreorder_p)
    {
      /* Avoid using %>%) since it adds excess whitespace.  */
      output_asm_insn (".set\tmacro", 0);
      output_asm_insn (".set\treorder", 0);
      set_noreorder = set_nomacro = 0;
    }

  if (!FUNCTION_NAME_ALREADY_DECLARED && !flag_inhibit_size_directive)
    {
      const char *fnname;

      /* Get the function name the same way that toplev.c does before calling
         assemble_start_function.  This is needed so that the name used here
         exactly matches the name used in ASM_DECLARE_FUNCTION_NAME.  */
      fnname = XSTR (XEXP (DECL_RTL (current_function_decl), 0), 0);
      fputs ("\t.end\t", file);
      assemble_name (file, fnname);
      fputs ("\n", file);
    }
}
\f
/* Save register REG to MEM.  Make the instruction frame-related.  */

static void
mips_save_reg (rtx reg, rtx mem)
{
  if (GET_MODE (reg) == DFmode && !TARGET_FLOAT64)
    {
      rtx x1, x2;

      if (mips_split_64bit_move_p (mem, reg))
        mips_split_doubleword_move (mem, reg);
      else
        mips_emit_move (mem, reg);

      x1 = mips_frame_set (mips_subword (mem, 0), mips_subword (reg, 0));
      x2 = mips_frame_set (mips_subword (mem, 1), mips_subword (reg, 1));
      mips_set_frame_expr (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, x1, x2)));
    }
  else
    {
      if (TARGET_MIPS16
          && REGNO (reg) != GP_REG_FIRST + 31
          && !M16_REG_P (REGNO (reg)))
        {
          /* Save a non-mips16 register by moving it through a temporary.
             We don't need to do this for $31 since there's a special
             instruction for it.  */
          mips_emit_move (MIPS_PROLOGUE_TEMP (GET_MODE (reg)), reg);
          mips_emit_move (mem, MIPS_PROLOGUE_TEMP (GET_MODE (reg)));
        }
      else
        mips_emit_move (mem, reg);

      mips_set_frame_expr (mips_frame_set (mem, reg));
    }
}

/* The __gnu_local_gp symbol.  */

static GTY(()) rtx mips_gnu_local_gp;

/* If we're generating n32 or n64 abicalls, emit instructions
   to set up the global pointer.  */

static void
mips_emit_loadgp (void)
{
  rtx addr, offset, incoming_address, base, index;

  switch (mips_current_loadgp_style ())
    {
    case LOADGP_ABSOLUTE:
      if (mips_gnu_local_gp == NULL)
        {
          mips_gnu_local_gp = gen_rtx_SYMBOL_REF (Pmode, "__gnu_local_gp");
          SYMBOL_REF_FLAGS (mips_gnu_local_gp) |= SYMBOL_FLAG_LOCAL;
        }
      emit_insn (gen_loadgp_absolute (mips_gnu_local_gp));
      break;

    case LOADGP_NEWABI:
      addr = XEXP (DECL_RTL (current_function_decl), 0);
      offset = mips_unspec_address (addr, SYMBOL_GOTOFF_LOADGP);
      incoming_address = gen_rtx_REG (Pmode, PIC_FUNCTION_ADDR_REGNUM);
      emit_insn (gen_loadgp_newabi (offset, incoming_address));
      if (!TARGET_EXPLICIT_RELOCS)
        emit_insn (gen_loadgp_blockage ());
      break;

    case LOADGP_RTP:
      base = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (VXWORKS_GOTT_BASE));
      index = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (VXWORKS_GOTT_INDEX));
      emit_insn (gen_loadgp_rtp (base, index));
      if (!TARGET_EXPLICIT_RELOCS)
        emit_insn (gen_loadgp_blockage ());
      break;

    default:
      break;
    }
}

/* Expand the prologue into a bunch of separate insns.  */

void
mips_expand_prologue (void)
{
  HOST_WIDE_INT size;
  unsigned int nargs;
  rtx insn;

  if (cfun->machine->global_pointer > 0)
    SET_REGNO (pic_offset_table_rtx, cfun->machine->global_pointer);

  size = cfun->machine->frame.total_size;

  /* Save the registers.  Allocate up to MIPS_MAX_FIRST_STACK_STEP
     bytes beforehand; this is enough to cover the register save area
     without going out of range.  */
  if ((cfun->machine->frame.mask | cfun->machine->frame.fmask) != 0)
    {
      HOST_WIDE_INT step1;

      step1 = MIN (size, MIPS_MAX_FIRST_STACK_STEP);

      if (GENERATE_MIPS16E_SAVE_RESTORE)
        {
          HOST_WIDE_INT offset;
          unsigned int mask, regno;

          /* Try to merge argument stores into the save instruction.  */
          nargs = mips16e_collect_argument_saves ();

          /* Build the save instruction.  */
          mask = cfun->machine->frame.mask;
          insn = mips16e_build_save_restore (false, &mask, &offset,
                                             nargs, step1);
          RTX_FRAME_RELATED_P (emit_insn (insn)) = 1;
          size -= step1;

          /* Check if we need to save other registers.  */
          for (regno = GP_REG_FIRST; regno < GP_REG_LAST; regno++)
            if (BITSET_P (mask, regno - GP_REG_FIRST))
              {
                offset -= GET_MODE_SIZE (gpr_mode);
                mips_save_restore_reg (gpr_mode, regno, offset, mips_save_reg);
              }
        }
      else
        {
          insn = gen_add3_insn (stack_pointer_rtx,
                                stack_pointer_rtx,
                                GEN_INT (-step1));
          RTX_FRAME_RELATED_P (emit_insn (insn)) = 1;
          size -= step1;
          mips_for_each_saved_reg (size, mips_save_reg);
        }
    }

  /* Allocate the rest of the frame.  */
  if (size > 0)
    {
      if (SMALL_OPERAND (-size))
        RTX_FRAME_RELATED_P (emit_insn (gen_add3_insn (stack_pointer_rtx,
                                                       stack_pointer_rtx,
                                                       GEN_INT (-size)))) = 1;
      else
        {
          mips_emit_move (MIPS_PROLOGUE_TEMP (Pmode), GEN_INT (size));
          if (TARGET_MIPS16)
            {
              /* There are no instructions to add or subtract registers
                 from the stack pointer, so use the frame pointer as a
                 temporary.  We should always be using a frame pointer
                 in this case anyway.  */
              gcc_assert (frame_pointer_needed);
              mips_emit_move (hard_frame_pointer_rtx, stack_pointer_rtx);
              emit_insn (gen_sub3_insn (hard_frame_pointer_rtx,
                                        hard_frame_pointer_rtx,
                                        MIPS_PROLOGUE_TEMP (Pmode)));
              mips_emit_move (stack_pointer_rtx, hard_frame_pointer_rtx);
            }
          else
            emit_insn (gen_sub3_insn (stack_pointer_rtx,
                                      stack_pointer_rtx,
                                      MIPS_PROLOGUE_TEMP (Pmode)));

          /* Describe the combined effect of the previous instructions.  */
          mips_set_frame_expr
            (gen_rtx_SET (VOIDmode, stack_pointer_rtx,
                          plus_constant (stack_pointer_rtx, -size)));
        }
    }

  /* Set up the frame pointer, if we're using one.  */
  if (frame_pointer_needed)
    {
      HOST_WIDE_INT offset;

      offset = cfun->machine->frame.hard_frame_pointer_offset;
      if (offset == 0)
        {
          insn = mips_emit_move (hard_frame_pointer_rtx, stack_pointer_rtx);
          RTX_FRAME_RELATED_P (insn) = 1;
        }
      else if (SMALL_OPERAND (offset))
        {
          insn = gen_add3_insn (hard_frame_pointer_rtx,
                                stack_pointer_rtx, GEN_INT (offset));
          RTX_FRAME_RELATED_P (emit_insn (insn)) = 1;
        }
      else
        {
          mips_emit_move (MIPS_PROLOGUE_TEMP (Pmode), GEN_INT (offset));
          mips_emit_move (hard_frame_pointer_rtx, stack_pointer_rtx);
          emit_insn (gen_add3_insn (hard_frame_pointer_rtx,
                                    hard_frame_pointer_rtx,
                                    MIPS_PROLOGUE_TEMP (Pmode)));
          mips_set_frame_expr
            (gen_rtx_SET (VOIDmode, hard_frame_pointer_rtx,
                          plus_constant (stack_pointer_rtx, offset)));
        }
    }

  mips_emit_loadgp ();

  /* If generating o32/o64 abicalls, save $gp on the stack.  */
  if (TARGET_ABICALLS && TARGET_OLDABI && !current_function_is_leaf)
    emit_insn (gen_cprestore (GEN_INT (current_function_outgoing_args_size)));

  /* If we are profiling, make sure no instructions are scheduled before
     the call to mcount.  */

  if (current_function_profile)
    emit_insn (gen_blockage ());
}
\f
/* Emit instructions to restore register REG from slot MEM.  */

static void
mips_restore_reg (rtx reg, rtx mem)
{
  /* There's no mips16 instruction to load $31 directly.  Load into
     $7 instead and adjust the return insn appropriately.  */
  if (TARGET_MIPS16 && REGNO (reg) == GP_REG_FIRST + 31)
    reg = gen_rtx_REG (GET_MODE (reg), 7);

  if (TARGET_MIPS16 && !M16_REG_P (REGNO (reg)))
    {
      /* Can't restore directly; move through a temporary.  */
      mips_emit_move (MIPS_EPILOGUE_TEMP (GET_MODE (reg)), mem);
      mips_emit_move (reg, MIPS_EPILOGUE_TEMP (GET_MODE (reg)));
    }
  else
    mips_emit_move (reg, mem);
}


/* Expand the epilogue into a bunch of separate insns.  SIBCALL_P is true
   if this epilogue precedes a sibling call, false if it is for a normal
   "epilogue" pattern.  */

void
mips_expand_epilogue (int sibcall_p)
{
  HOST_WIDE_INT step1, step2;
  rtx base, target;

  if (!sibcall_p && mips_can_use_return_insn ())
    {
      emit_jump_insn (gen_return ());
      return;
    }

  /* In mips16 mode, if the return value should go into a floating-point
     register, we need to call a helper routine to copy it over.  */
  if (mips16_cfun_returns_in_fpr_p ())
    {
      char *name;
      rtx func;
      rtx insn;
      rtx retval;
      rtx call;
      tree id;
      tree return_type;
      enum machine_mode return_mode;

      return_type = DECL_RESULT (current_function_decl);
      return_mode = DECL_MODE (return_type);

      name = ACONCAT (("__mips16_ret_",
                       mips16_call_stub_mode_suffix (return_mode),
                       NULL));
      id = get_identifier (name);
      func = gen_rtx_SYMBOL_REF (Pmode, IDENTIFIER_POINTER (id));
      retval = gen_rtx_REG (return_mode, GP_RETURN);
      call = gen_call_value_internal (retval, func, const0_rtx);
      insn = emit_call_insn (call);
      use_reg (&CALL_INSN_FUNCTION_USAGE (insn), retval);
    }

  /* Split the frame into two.  STEP1 is the amount of stack we should
     deallocate before restoring the registers.  STEP2 is the amount we
     should deallocate afterwards.

     Start off by assuming that no registers need to be restored.  */
  step1 = cfun->machine->frame.total_size;
  step2 = 0;

  /* Work out which register holds the frame address.  */
  if (!frame_pointer_needed)
    base = stack_pointer_rtx;
  else
    {
      base = hard_frame_pointer_rtx;
      step1 -= cfun->machine->frame.hard_frame_pointer_offset;
    }

  /* If we need to restore registers, deallocate as much stack as
     possible in the second step without going out of range.  */
  if ((cfun->machine->frame.mask | cfun->machine->frame.fmask) != 0)
    {
      step2 = MIN (step1, MIPS_MAX_FIRST_STACK_STEP);
      step1 -= step2;
    }

  /* Set TARGET to BASE + STEP1.  */
  target = base;
  if (step1 > 0)
    {
      rtx adjust;

      /* Get an rtx for STEP1 that we can add to BASE.  */
      adjust = GEN_INT (step1);
      if (!SMALL_OPERAND (step1))
        {
          mips_emit_move (MIPS_EPILOGUE_TEMP (Pmode), adjust);
          adjust = MIPS_EPILOGUE_TEMP (Pmode);
        }

      /* Normal mode code can copy the result straight into $sp.  */
      if (!TARGET_MIPS16)
        target = stack_pointer_rtx;

      emit_insn (gen_add3_insn (target, base, adjust));
    }

  /* Copy TARGET into the stack pointer.  */
  if (target != stack_pointer_rtx)
    mips_emit_move (stack_pointer_rtx, target);

  /* If we're using addressing macros, $gp is implicitly used by all
     SYMBOL_REFs.  We must emit a blockage insn before restoring $gp
     from the stack.  */
  if (TARGET_CALL_SAVED_GP && !TARGET_EXPLICIT_RELOCS)
    emit_insn (gen_blockage ());

  if (GENERATE_MIPS16E_SAVE_RESTORE && cfun->machine->frame.mask != 0)
    {
      unsigned int regno, mask;
      HOST_WIDE_INT offset;
      rtx restore;

      /* Generate the restore instruction.  */
      mask = cfun->machine->frame.mask;
      restore = mips16e_build_save_restore (true, &mask, &offset, 0, step2);

      /* Restore any other registers manually.  */
      for (regno = GP_REG_FIRST; regno < GP_REG_LAST; regno++)
        if (BITSET_P (mask, regno - GP_REG_FIRST))
          {
            offset -= GET_MODE_SIZE (gpr_mode);
            mips_save_restore_reg (gpr_mode, regno, offset, mips_restore_reg);
          }

      /* Restore the remaining registers and deallocate the final bit
         of the frame.  */
      emit_insn (restore);
    }
  else
    {
      /* Restore the registers.  */
      mips_for_each_saved_reg (cfun->machine->frame.total_size - step2,
                               mips_restore_reg);

      /* Deallocate the final bit of the frame.  */
      if (step2 > 0)
        emit_insn (gen_add3_insn (stack_pointer_rtx,
                                  stack_pointer_rtx,
                                  GEN_INT (step2)));
    }

  /* Add in the __builtin_eh_return stack adjustment.  We need to
     use a temporary in mips16 code.  */
  if (current_function_calls_eh_return)
    {
      if (TARGET_MIPS16)
        {
          mips_emit_move (MIPS_EPILOGUE_TEMP (Pmode), stack_pointer_rtx);
          emit_insn (gen_add3_insn (MIPS_EPILOGUE_TEMP (Pmode),
                                    MIPS_EPILOGUE_TEMP (Pmode),
                                    EH_RETURN_STACKADJ_RTX));
          mips_emit_move (stack_pointer_rtx, MIPS_EPILOGUE_TEMP (Pmode));
        }
      else
        emit_insn (gen_add3_insn (stack_pointer_rtx,
                                  stack_pointer_rtx,
                                  EH_RETURN_STACKADJ_RTX));
    }

  if (!sibcall_p)
    {
      /* When generating MIPS16 code, the normal mips_for_each_saved_reg
         path will restore the return address into $7 rather than $31.  */
      if (TARGET_MIPS16
          && !GENERATE_MIPS16E_SAVE_RESTORE
          && (cfun->machine->frame.mask & RA_MASK) != 0)
        emit_jump_insn (gen_return_internal (gen_rtx_REG (Pmode,
                                                          GP_REG_FIRST + 7)));
      else
        emit_jump_insn (gen_return_internal (gen_rtx_REG (Pmode,
                                                          GP_REG_FIRST + 31)));
    }
}
\f
/* Return nonzero if this function is known to have a null epilogue.
   This allows the optimizer to omit jumps to jumps if no stack
   was created.  */

int
mips_can_use_return_insn (void)
{
  if (! reload_completed)
    return 0;

  if (current_function_profile)
    return 0;

  /* In mips16 mode, a function that returns a floating point value
     needs to arrange to copy the return value into the floating point
     registers.  */
  if (mips16_cfun_returns_in_fpr_p ())
    return 0;

  return cfun->machine->frame.total_size == 0;
}
\f
/* Implement HARD_REGNO_NREGS.  The size of FP registers is controlled
   by UNITS_PER_FPREG.  The size of FP status registers is always 4, because
   they only hold condition code modes, and CCmode is always considered to
   be 4 bytes wide.  All other registers are word sized.  */

unsigned int
mips_hard_regno_nregs (int regno, enum machine_mode mode)
{
  if (ST_REG_P (regno))
    return ((GET_MODE_SIZE (mode) + 3) / 4);
  else if (! FP_REG_P (regno))
    return ((GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD);
  else
    return ((GET_MODE_SIZE (mode) + UNITS_PER_FPREG - 1) / UNITS_PER_FPREG);
}

/* Implement CLASS_MAX_NREGS.

   - UNITS_PER_FPREG controls the number of registers needed by FP_REGS.

   - ST_REGS are always hold CCmode values, and CCmode values are
     considered to be 4 bytes wide.

   All other register classes are covered by UNITS_PER_WORD.  Note that
   this is true even for unions of integer and float registers when the
   latter are smaller than the former.  The only supported combination
   in which case this occurs is -mgp64 -msingle-float, which has 64-bit
   words but 32-bit float registers.  A word-based calculation is correct
   in that case since -msingle-float disallows multi-FPR values.  */

int
mips_class_max_nregs (enum reg_class class ATTRIBUTE_UNUSED,
                      enum machine_mode mode)
{
  if (class == ST_REGS)
    return (GET_MODE_SIZE (mode) + 3) / 4;
  else if (class == FP_REGS)
    return (GET_MODE_SIZE (mode) + UNITS_PER_FPREG - 1) / UNITS_PER_FPREG;
  else
    return (GET_MODE_SIZE (mode) + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
}

/* Return true if registers of class CLASS cannot change from mode FROM
   to mode TO.  */

bool
mips_cannot_change_mode_class (enum machine_mode from ATTRIBUTE_UNUSED,
                               enum machine_mode to ATTRIBUTE_UNUSED,
                               enum reg_class class)
{
  /* There are several problems with changing the modes of values
     in floating-point registers:

     - When a multi-word value is stored in paired floating-point
       registers, the first register always holds the low word.
       We therefore can't allow FPRs to change between single-word
       and multi-word modes on big-endian targets.

     - GCC assumes that each word of a multiword register can be accessed
       individually using SUBREGs.  This is not true for floating-point
       registers if they are bigger than a word.

     - Loading a 32-bit value into a 64-bit floating-point register
       will not sign-extend the value, despite what LOAD_EXTEND_OP says.
       We can't allow FPRs to change from SImode to to a wider mode on
       64-bit targets.

     - If the FPU has already interpreted a value in one format, we must
       not ask it to treat the value as having a different format.

     We therefore only allow changes between 4-byte and smaller integer
     values, all of which have the "W" format as far as the FPU is
     concerned.  */
  return (reg_classes_intersect_p (FP_REGS, class)
          && (GET_MODE_CLASS (from) != MODE_INT
              || GET_MODE_CLASS (to) != MODE_INT
              || GET_MODE_SIZE (from) > 4
              || GET_MODE_SIZE (to) > 4));
}

/* Return true if moves in mode MODE can use the FPU's mov.fmt instruction.  */

static bool
mips_mode_ok_for_mov_fmt_p (enum machine_mode mode)
{
  switch (mode)
    {
    case SFmode:
      return TARGET_HARD_FLOAT;

    case DFmode:
      return TARGET_HARD_FLOAT && TARGET_DOUBLE_FLOAT;

    case V2SFmode:
      return TARGET_HARD_FLOAT && TARGET_PAIRED_SINGLE_FLOAT;

    default:
      return false;
    }
}

/* Implement PREFERRED_RELOAD_CLASS.  */

enum reg_class
mips_preferred_reload_class (rtx x, enum reg_class class)
{
  if (mips_dangerous_for_la25_p (x) && reg_class_subset_p (LEA_REGS, class))
    return LEA_REGS;

  if (reg_class_subset_p (FP_REGS, class)
      && mips_mode_ok_for_mov_fmt_p (GET_MODE (x)))
    return FP_REGS;

  if (reg_class_subset_p (GR_REGS, class))
    class = GR_REGS;

  if (TARGET_MIPS16 && reg_class_subset_p (M16_REGS, class))
    class = M16_REGS;

  return class;
}

/* Return a number assessing the cost of moving a register in class
   FROM to class TO.  The classes are expressed using the enumeration
   values such as `GENERAL_REGS'.  A value of 2 is the default; other
   values are interpreted relative to that.

   It is not required that the cost always equal 2 when FROM is the
   same as TO; on some machines it is expensive to move between
   registers if they are not general registers.

   If reload sees an insn consisting of a single `set' between two
   hard registers, and if `REGISTER_MOVE_COST' applied to their
   classes returns a value of 2, reload does not check to ensure that
   the constraints of the insn are met.  Setting a cost of other than
   2 will allow reload to verify that the constraints are met.  You
   should do this if the `movM' pattern's constraints do not allow
   such copying.

   ??? We make the cost of moving from HI/LO into general
   registers the same as for one of moving general registers to
   HI/LO for TARGET_MIPS16 in order to prevent allocating a
   pseudo to HI/LO.  This might hurt optimizations though, it
   isn't clear if it is wise.  And it might not work in all cases.  We
   could solve the DImode LO reg problem by using a multiply, just
   like reload_{in,out}si.  We could solve the SImode/HImode HI reg
   problem by using divide instructions.  divu puts the remainder in
   the HI reg, so doing a divide by -1 will move the value in the HI
   reg for all values except -1.  We could handle that case by using a
   signed divide, e.g.  -1 / 2 (or maybe 1 / -2?).  We'd have to emit
   a compare/branch to test the input value to see which instruction
   we need to use.  This gets pretty messy, but it is feasible.  */

int
mips_register_move_cost (enum machine_mode mode,
                         enum reg_class to, enum reg_class from)
{
  if (TARGET_MIPS16)
    {
      if (reg_class_subset_p (from, GENERAL_REGS)
          && reg_class_subset_p (to, GENERAL_REGS))
        {
          if (reg_class_subset_p (from, M16_REGS)
              || reg_class_subset_p (to, M16_REGS))
            return 2;
          /* Two MOVEs.  */
          return 4;
        }
    }
  else if (reg_class_subset_p (from, GENERAL_REGS))
    {
      if (reg_class_subset_p (to, GENERAL_REGS))
        return 2;
      if (reg_class_subset_p (to, FP_REGS))
        return 4;
      if (reg_class_subset_p (to, ALL_COP_AND_GR_REGS))
        return 5;
      if (reg_class_subset_p (to, ACC_REGS))
        return 6;
    }
  else if (reg_class_subset_p (to, GENERAL_REGS))
    {
      if (reg_class_subset_p (from, FP_REGS))
        return 4;
      if (reg_class_subset_p (from, ST_REGS))
        /* LUI followed by MOVF.  */
        return 4;
      if (reg_class_subset_p (from, ALL_COP_AND_GR_REGS))
        return 5;
      if (reg_class_subset_p (from, ACC_REGS))
        return 6;
    }
  else if (reg_class_subset_p (from, FP_REGS))
    {
      if (reg_class_subset_p (to, FP_REGS)
          && mips_mode_ok_for_mov_fmt_p (mode))
        return 4;
      if (reg_class_subset_p (to, ST_REGS))
        /* An expensive sequence.  */
        return 8;
    }

  return 12;
}

/* This function returns the register class required for a secondary
   register when copying between one of the registers in CLASS, and X,
   using MODE.  If IN_P is nonzero, the copy is going from X to the
   register, otherwise the register is the source.  A return value of
   NO_REGS means that no secondary register is required.  */

enum reg_class
mips_secondary_reload_class (enum reg_class class,
                             enum machine_mode mode, rtx x, int in_p)
{
  int regno;

  /* If X is a constant that cannot be loaded into $25, it must be loaded
     into some other GPR.  No other register class allows a direct move.  */
  if (mips_dangerous_for_la25_p (x))
    return reg_class_subset_p (class, LEA_REGS) ? NO_REGS : LEA_REGS;

  regno = true_regnum (x);
  if (TARGET_MIPS16)
    {
      /* In MIPS16 mode, every move must involve a member of M16_REGS.  */
      if (!reg_class_subset_p (class, M16_REGS) && !M16_REG_P (regno))
        return M16_REGS;

      /* We can't really copy to HI or LO at all in MIPS16 mode.  */
      if (in_p ? reg_classes_intersect_p (class, ACC_REGS) : ACC_REG_P (regno))
        return M16_REGS;

      return NO_REGS;
    }

  /* Copying from accumulator registers to anywhere other than a general
     register requires a temporary general register.  */
  if (reg_class_subset_p (class, ACC_REGS))
    return GP_REG_P (regno) ? NO_REGS : GR_REGS;
  if (ACC_REG_P (regno))
    return reg_class_subset_p (class, GR_REGS) ? NO_REGS : GR_REGS;

  /* We can only copy a value to a condition code register from a
     floating point register, and even then we require a scratch
     floating point register.  We can only copy a value out of a
     condition code register into a general register.  */
  if (reg_class_subset_p (class, ST_REGS))
    {
      if (in_p)
        return FP_REGS;
      return GP_REG_P (regno) ? NO_REGS : GR_REGS;
    }
  if (ST_REG_P (regno))
    {
      if (!in_p)
        return FP_REGS;
      return reg_class_subset_p (class, GR_REGS) ? NO_REGS : GR_REGS;
    }

  if (reg_class_subset_p (class, FP_REGS))
    {
      if (MEM_P (x)
          && (GET_MODE_SIZE (mode) == 4 || GET_MODE_SIZE (mode) == 8))
        /* In this case we can use lwc1, swc1, ldc1 or sdc1.  We'll use
           pairs of lwc1s and swc1s if ldc1 and sdc1 are not supported.  */
        return NO_REGS;

      if (GP_REG_P (regno) || x == CONST0_RTX (mode))
        /* In this case we can use mtc1, mfc1, dmtc1 or dmfc1.  */
        return NO_REGS;

      if (CONSTANT_P (x) && !targetm.cannot_force_const_mem (x))
        /* We can force the constant to memory and use lwc1
           and ldc1.  As above, we will use pairs of lwc1s if
           ldc1 is not supported.  */
        return NO_REGS;

      if (FP_REG_P (regno) && mips_mode_ok_for_mov_fmt_p (mode))
        /* In this case we can use mov.fmt.  */
        return NO_REGS;

      /* Otherwise, we need to reload through an integer register.  */
      return GR_REGS;
    }
  if (FP_REG_P (regno))
    return reg_class_subset_p (class, GR_REGS) ? NO_REGS : GR_REGS;

  return NO_REGS;
}

/* SImode values are represented as sign-extended to DImode.  */

static int
mips_mode_rep_extended (enum machine_mode mode, enum machine_mode mode_rep)
{
  if (TARGET_64BIT && mode == SImode && mode_rep == DImode)
    return SIGN_EXTEND;

  return UNKNOWN;
}

static bool
mips_valid_pointer_mode (enum machine_mode mode)
{
  return (mode == SImode || (TARGET_64BIT && mode == DImode));
}

/* Target hook for vector_mode_supported_p.  */

static bool
mips_vector_mode_supported_p (enum machine_mode mode)
{
  switch (mode)
    {
    case V2SFmode:
      return TARGET_PAIRED_SINGLE_FLOAT;

    case V2HImode:
    case V4QImode:
    case V2HQmode:
    case V2UHQmode:
    case V2HAmode:
    case V2UHAmode:
    case V4QQmode:
    case V4UQQmode:
      return TARGET_DSP;

    default:
      return false;
    }
}

/* Implement TARGET_SCALAR_MODE_SUPPORTED_P.  */

static bool
mips_scalar_mode_supported_p (enum machine_mode mode)
{
  if (ALL_FIXED_POINT_MODE_P (mode)
      && GET_MODE_PRECISION (mode) <= 2 * BITS_PER_WORD)
    return true;

  return default_scalar_mode_supported_p (mode);
}
/* This function does three things:

   - Register the special divsi3 and modsi3 functions if -mfix-vr4120.
   - Register the mips16 hardware floating point stubs.
   - Register the gofast functions if selected using --enable-gofast.  */

#include "config/gofast.h"

static void
mips_init_libfuncs (void)
{
  if (TARGET_FIX_VR4120)
    {
      set_optab_libfunc (sdiv_optab, SImode, "__vr4120_divsi3");
      set_optab_libfunc (smod_optab, SImode, "__vr4120_modsi3");
    }

  if (TARGET_MIPS16 && TARGET_HARD_FLOAT_ABI)
    {
      set_optab_libfunc (add_optab, SFmode, "__mips16_addsf3");
      set_optab_libfunc (sub_optab, SFmode, "__mips16_subsf3");
      set_optab_libfunc (smul_optab, SFmode, "__mips16_mulsf3");
      set_optab_libfunc (sdiv_optab, SFmode, "__mips16_divsf3");

      set_optab_libfunc (eq_optab, SFmode, "__mips16_eqsf2");
      set_optab_libfunc (ne_optab, SFmode, "__mips16_nesf2");
      set_optab_libfunc (gt_optab, SFmode, "__mips16_gtsf2");
      set_optab_libfunc (ge_optab, SFmode, "__mips16_gesf2");
      set_optab_libfunc (lt_optab, SFmode, "__mips16_ltsf2");
      set_optab_libfunc (le_optab, SFmode, "__mips16_lesf2");
      set_optab_libfunc (unord_optab, SFmode, "__mips16_unordsf2");

      set_conv_libfunc (sfix_optab, SImode, SFmode, "__mips16_fix_truncsfsi");
      set_conv_libfunc (sfloat_optab, SFmode, SImode, "__mips16_floatsisf");
      set_conv_libfunc (ufloat_optab, SFmode, SImode, "__mips16_floatunsisf");

      if (TARGET_DOUBLE_FLOAT)
        {
          set_optab_libfunc (add_optab, DFmode, "__mips16_adddf3");
          set_optab_libfunc (sub_optab, DFmode, "__mips16_subdf3");
          set_optab_libfunc (smul_optab, DFmode, "__mips16_muldf3");
          set_optab_libfunc (sdiv_optab, DFmode, "__mips16_divdf3");

          set_optab_libfunc (eq_optab, DFmode, "__mips16_eqdf2");
          set_optab_libfunc (ne_optab, DFmode, "__mips16_nedf2");
          set_optab_libfunc (gt_optab, DFmode, "__mips16_gtdf2");
          set_optab_libfunc (ge_optab, DFmode, "__mips16_gedf2");
          set_optab_libfunc (lt_optab, DFmode, "__mips16_ltdf2");
          set_optab_libfunc (le_optab, DFmode, "__mips16_ledf2");
          set_optab_libfunc (unord_optab, DFmode, "__mips16_unorddf2");

          set_conv_libfunc (sext_optab, DFmode, SFmode, "__mips16_extendsfdf2");
          set_conv_libfunc (trunc_optab, SFmode, DFmode, "__mips16_truncdfsf2");

          set_conv_libfunc (sfix_optab, SImode, DFmode, "__mips16_fix_truncdfsi");
          set_conv_libfunc (sfloat_optab, DFmode, SImode, "__mips16_floatsidf");
          set_conv_libfunc (ufloat_optab, DFmode, SImode, "__mips16_floatunsidf");
        }
    }
  else
    gofast_maybe_init_libfuncs ();
}

/* Return the length of INSN.  LENGTH is the initial length computed by
   attributes in the machine-description file.  */

int
mips_adjust_insn_length (rtx insn, int length)
{
  /* A unconditional jump has an unfilled delay slot if it is not part
     of a sequence.  A conditional jump normally has a delay slot, but
     does not on MIPS16.  */
  if (CALL_P (insn) || (TARGET_MIPS16 ? simplejump_p (insn) : JUMP_P (insn)))
    length += 4;

  /* See how many nops might be needed to avoid hardware hazards.  */
  if (!cfun->machine->ignore_hazard_length_p && INSN_CODE (insn) >= 0)
    switch (get_attr_hazard (insn))
      {
      case HAZARD_NONE:
        break;

      case HAZARD_DELAY:
        length += 4;
        break;

      case HAZARD_HILO:
        length += 8;
        break;
      }

  /* All MIPS16 instructions are a measly two bytes.  */
  if (TARGET_MIPS16)
    length /= 2;

  return length;
}


/* Return an asm sequence to start a noat block and load the address
   of a label into $1.  */

const char *
mips_output_load_label (void)
{
  if (TARGET_EXPLICIT_RELOCS)
    switch (mips_abi)
      {
      case ABI_N32:
        return "%[lw\t%@,%%got_page(%0)(%+)\n\taddiu\t%@,%@,%%got_ofst(%0)";

      case ABI_64:
        return "%[ld\t%@,%%got_page(%0)(%+)\n\tdaddiu\t%@,%@,%%got_ofst(%0)";

      default:
        if (ISA_HAS_LOAD_DELAY)
          return "%[lw\t%@,%%got(%0)(%+)%#\n\taddiu\t%@,%@,%%lo(%0)";
        return "%[lw\t%@,%%got(%0)(%+)\n\taddiu\t%@,%@,%%lo(%0)";
      }
  else
    {
      if (Pmode == DImode)
        return "%[dla\t%@,%0";
      else
        return "%[la\t%@,%0";
    }
}

/* Return the assembly code for INSN, which has the operands given by
   OPERANDS, and which branches to OPERANDS[1] if some condition is true.
   BRANCH_IF_TRUE is the asm template that should be used if OPERANDS[1]
   is in range of a direct branch.  BRANCH_IF_FALSE is an inverted
   version of BRANCH_IF_TRUE.  */

const char *
mips_output_conditional_branch (rtx insn, rtx *operands,
                                const char *branch_if_true,
                                const char *branch_if_false)
{
  unsigned int length;
  rtx taken, not_taken;

  length = get_attr_length (insn);
  if (length <= 8)
    {
      /* Just a simple conditional branch.  */
      mips_branch_likely = (final_sequence && INSN_ANNULLED_BRANCH_P (insn));
      return branch_if_true;
    }

  /* Generate a reversed branch around a direct jump.  This fallback does
     not use branch-likely instructions.  */
  mips_branch_likely = false;
  not_taken = gen_label_rtx ();
  taken = operands[1];

  /* Generate the reversed branch to NOT_TAKEN.  */
  operands[1] = not_taken;
  output_asm_insn (branch_if_false, operands);

  /* If INSN has a delay slot, we must provide delay slots for both the
     branch to NOT_TAKEN and the conditional jump.  We must also ensure
     that INSN's delay slot is executed in the appropriate cases.  */
  if (final_sequence)
    {
      /* This first delay slot will always be executed, so use INSN's
         delay slot if is not annulled.  */
      if (!INSN_ANNULLED_BRANCH_P (insn))
        {
          final_scan_insn (XVECEXP (final_sequence, 0, 1),
                           asm_out_file, optimize, 1, NULL);
          INSN_DELETED_P (XVECEXP (final_sequence, 0, 1)) = 1;
        }
      else
        output_asm_insn ("nop", 0);
      fprintf (asm_out_file, "\n");
    }

  /* Output the unconditional branch to TAKEN.  */
  if (length <= 16)
    output_asm_insn ("j\t%0%/", &taken);
  else
    {
      output_asm_insn (mips_output_load_label (), &taken);
      output_asm_insn ("jr\t%@%]%/", 0);
    }

  /* Now deal with its delay slot; see above.  */
  if (final_sequence)
    {
      /* This delay slot will only be executed if the branch is taken.
         Use INSN's delay slot if is annulled.  */
      if (INSN_ANNULLED_BRANCH_P (insn))
        {
          final_scan_insn (XVECEXP (final_sequence, 0, 1),
                           asm_out_file, optimize, 1, NULL);
          INSN_DELETED_P (XVECEXP (final_sequence, 0, 1)) = 1;
        }
      else
        output_asm_insn ("nop", 0);
      fprintf (asm_out_file, "\n");
    }

  /* Output NOT_TAKEN.  */
  (*targetm.asm_out.internal_label) (asm_out_file, "L",
                                     CODE_LABEL_NUMBER (not_taken));
  return "";
}

/* Return the assembly code for INSN, which branches to OPERANDS[1]
   if some ordered condition is true.  The condition is given by
   OPERANDS[0] if !INVERTED_P, otherwise it is the inverse of
   OPERANDS[0].  OPERANDS[2] is the comparison's first operand;
   its second is always zero.  */

const char *
mips_output_order_conditional_branch (rtx insn, rtx *operands, bool inverted_p)
{
  const char *branch[2];

  /* Make BRANCH[1] branch to OPERANDS[1] when the condition is true.
     Make BRANCH[0] branch on the inverse condition.  */
  switch (GET_CODE (operands[0]))
    {
      /* These cases are equivalent to comparisons against zero.  */
    case LEU:
      inverted_p = !inverted_p;
      /* Fall through.  */
    case GTU:
      branch[!inverted_p] = MIPS_BRANCH ("bne", "%2,%.,%1");
      branch[inverted_p] = MIPS_BRANCH ("beq", "%2,%.,%1");
      break;

      /* These cases are always true or always false.  */
    case LTU:
      inverted_p = !inverted_p;
      /* Fall through.  */
    case GEU:
      branch[!inverted_p] = MIPS_BRANCH ("beq", "%.,%.,%1");
      branch[inverted_p] = MIPS_BRANCH ("bne", "%.,%.,%1");
      break;

    default:
      branch[!inverted_p] = MIPS_BRANCH ("b%C0z", "%2,%1");
      branch[inverted_p] = MIPS_BRANCH ("b%N0z", "%2,%1");
      break;
    }
  return mips_output_conditional_branch (insn, operands, branch[1], branch[0]);
}
\f
/* Used to output div or ddiv instruction DIVISION, which has the operands
   given by OPERANDS.  Add in a divide-by-zero check if needed.

   When working around R4000 and R4400 errata, we need to make sure that
   the division is not immediately followed by a shift[1][2].  We also
   need to stop the division from being put into a branch delay slot[3].
   The easiest way to avoid both problems is to add a nop after the
   division.  When a divide-by-zero check is needed, this nop can be
   used to fill the branch delay slot.

   [1] If a double-word or a variable shift executes immediately
       after starting an integer division, the shift may give an
       incorrect result.  See quotations of errata #16 and #28 from
       "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0"
       in mips.md for details.

   [2] A similar bug to [1] exists for all revisions of the
       R4000 and the R4400 when run in an MC configuration.
       From "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0":

       "19. In this following sequence:

                    ddiv                (or ddivu or div or divu)
                    dsll32              (or dsrl32, dsra32)

            if an MPT stall occurs, while the divide is slipping the cpu
            pipeline, then the following double shift would end up with an
            incorrect result.

            Workaround: The compiler needs to avoid generating any
            sequence with divide followed by extended double shift."

       This erratum is also present in "MIPS R4400MC Errata, Processor
       Revision 1.0" and "MIPS R4400MC Errata, Processor Revision 2.0
       & 3.0" as errata #10 and #4, respectively.

   [3] From "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0"
       (also valid for MIPS R4000MC processors):

       "52. R4000SC: This bug does not apply for the R4000PC.

            There are two flavors of this bug:

            1) If the instruction just after divide takes an RF exception
               (tlb-refill, tlb-invalid) and gets an instruction cache
               miss (both primary and secondary) and the line which is
               currently in secondary cache at this index had the first
               data word, where the bits 5..2 are set, then R4000 would
               get a wrong result for the div.

            ##1
                    nop
                    div r8, r9
                    -------------------         # end-of page. -tlb-refill
                    nop
            ##2
                    nop
                    div r8, r9
                    -------------------         # end-of page. -tlb-invalid
                    nop

            2) If the divide is in the taken branch delay slot, where the
               target takes RF exception and gets an I-cache miss for the
               exception vector or where I-cache miss occurs for the
               target address, under the above mentioned scenarios, the
               div would get wrong results.

            ##1
                    j   r2              # to next page mapped or unmapped
                    div r8,r9           # this bug would be there as long
                                        # as there is an ICache miss and
                    nop                 # the "data pattern" is present

            ##2
                    beq r0, r0, NextPage        # to Next page
                    div r8,r9
                    nop

            This bug is present for div, divu, ddiv, and ddivu
            instructions.

            Workaround: For item 1), OS could make sure that the next page
            after the divide instruction is also mapped.  For item 2), the
            compiler could make sure that the divide instruction is not in
            the branch delay slot."

       These processors have PRId values of 0x00004220 and 0x00004300 for
       the R4000 and 0x00004400, 0x00004500 and 0x00004600 for the R4400.  */

const char *
mips_output_division (const char *division, rtx *operands)
{
  const char *s;

  s = division;
  if (TARGET_FIX_R4000 || TARGET_FIX_R4400)
    {
      output_asm_insn (s, operands);
      s = "nop";
    }
  if (TARGET_CHECK_ZERO_DIV)
    {
      if (TARGET_MIPS16)
        {
          output_asm_insn (s, operands);
          s = "bnez\t%2,1f\n\tbreak\t7\n1:";
        }
      else if (GENERATE_DIVIDE_TRAPS)
        {
          output_asm_insn (s, operands);
          s = "teq\t%2,%.,7";
        }
      else
        {
          output_asm_insn ("%(bne\t%2,%.,1f", operands);
          output_asm_insn (s, operands);
          s = "break\t7%)\n1:";
        }
    }
  return s;
}
\f
/* Return true if INSN is a multiply-add or multiply-subtract
   instruction and PREV assigns to the accumulator operand.  */

bool
mips_linked_madd_p (rtx prev, rtx insn)
{
  rtx x;

  x = single_set (insn);
  if (x == 0)
    return false;

  x = SET_SRC (x);

  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 0)) == MULT
      && reg_set_p (XEXP (x, 1), prev))
    return true;

  if (GET_CODE (x) == MINUS
      && GET_CODE (XEXP (x, 1)) == MULT
      && reg_set_p (XEXP (x, 0), prev))
    return true;

  return false;
}

/* Implements a store data bypass check.  We need this because the cprestore
   pattern is type store, but defined using an UNSPEC.  This UNSPEC causes the
   default routine to abort.  We just return false for that case.  */
/* ??? Should try to give a better result here than assuming false.  */

int
mips_store_data_bypass_p (rtx out_insn, rtx in_insn)
{
  if (GET_CODE (PATTERN (in_insn)) == UNSPEC_VOLATILE)
    return false;

  return ! store_data_bypass_p (out_insn, in_insn);
}
\f
/* Implement TARGET_SCHED_ADJUST_COST.  We assume that anti and output
   dependencies have no cost, except on the 20Kc where output-dependence
   is treated like input-dependence.  */

static int
mips_adjust_cost (rtx insn ATTRIBUTE_UNUSED, rtx link,
                  rtx dep ATTRIBUTE_UNUSED, int cost)
{
  if (REG_NOTE_KIND (link) == REG_DEP_OUTPUT
      && TUNE_20KC)
    return cost;
  if (REG_NOTE_KIND (link) != 0)
    return 0;
  return cost;
}

/* Return the number of instructions that can be issued per cycle.  */

static int
mips_issue_rate (void)
{
  switch (mips_tune)
    {
    case PROCESSOR_74KC:
    case PROCESSOR_74KF2_1:
    case PROCESSOR_74KF1_1:
    case PROCESSOR_74KF3_2:
      /* The 74k is not strictly quad-issue cpu, but can be seen as one
         by the scheduler.  It can issue 1 ALU, 1 AGEN and 2 FPU insns,
         but in reality only a maximum of 3 insns can be issued as the
         floating point load/stores also require a slot in the AGEN pipe.  */
     return 4;

    case PROCESSOR_20KC:
    case PROCESSOR_R4130:
    case PROCESSOR_R5400:
    case PROCESSOR_R5500:
    case PROCESSOR_R7000:
    case PROCESSOR_R9000:
      return 2;

    case PROCESSOR_SB1:
    case PROCESSOR_SB1A:
      /* This is actually 4, but we get better performance if we claim 3.
         This is partly because of unwanted speculative code motion with the
         larger number, and partly because in most common cases we can't
         reach the theoretical max of 4.  */
      return 3;

    default:
      return 1;
    }
}

/* Implements TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD.  This should
   be as wide as the scheduling freedom in the DFA.  */

static int
mips_multipass_dfa_lookahead (void)
{
  /* Can schedule up to 4 of the 6 function units in any one cycle.  */
  if (TUNE_SB1)
    return 4;

  return 0;
}
\f
/* Remove the instruction at index LOWER from ready queue READY and
   reinsert it in front of the instruction at index HIGHER.  LOWER must
   be <= HIGHER.  */

static void
mips_promote_ready (rtx *ready, int lower, int higher)
{
  rtx new_head;
  int i;

  new_head = ready[lower];
  for (i = lower; i < higher; i++)
    ready[i] = ready[i + 1];
  ready[i] = new_head;
}

/* If the priority of the instruction at POS2 in the ready queue READY
   is within LIMIT units of that of the instruction at POS1, swap the
   instructions if POS2 is not already less than POS1.  */

static void
mips_maybe_swap_ready (rtx *ready, int pos1, int pos2, int limit)
{
  if (pos1 < pos2
      && INSN_PRIORITY (ready[pos1]) + limit >= INSN_PRIORITY (ready[pos2]))
    {
      rtx temp;
      temp = ready[pos1];
      ready[pos1] = ready[pos2];
      ready[pos2] = temp;
    }
}
\f
/* Used by TUNE_MACC_CHAINS to record the last scheduled instruction
   that may clobber hi or lo.  */

static rtx mips_macc_chains_last_hilo;

/* A TUNE_MACC_CHAINS helper function.  Record that instruction INSN has
   been scheduled, updating mips_macc_chains_last_hilo appropriately.  */

static void
mips_macc_chains_record (rtx insn)
{
  if (get_attr_may_clobber_hilo (insn))
    mips_macc_chains_last_hilo = insn;
}

/* A TUNE_MACC_CHAINS helper function.  Search ready queue READY, which
   has NREADY elements, looking for a multiply-add or multiply-subtract
   instruction that is cumulative with mips_macc_chains_last_hilo.
   If there is one, promote it ahead of anything else that might
   clobber hi or lo.  */

static void
mips_macc_chains_reorder (rtx *ready, int nready)
{
  int i, j;

  if (mips_macc_chains_last_hilo != 0)
    for (i = nready - 1; i >= 0; i--)
      if (mips_linked_madd_p (mips_macc_chains_last_hilo, ready[i]))
        {
          for (j = nready - 1; j > i; j--)
            if (recog_memoized (ready[j]) >= 0
                && get_attr_may_clobber_hilo (ready[j]))
              {
                mips_promote_ready (ready, i, j);
                break;
              }
          break;
        }
}
\f
/* The last instruction to be scheduled.  */

static rtx vr4130_last_insn;

/* A note_stores callback used by vr4130_true_reg_dependence_p.  DATA
   points to an rtx that is initially an instruction.  Nullify the rtx
   if the instruction uses the value of register X.  */

static void
vr4130_true_reg_dependence_p_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data)
{
  rtx *insn_ptr = data;
  if (REG_P (x)
      && *insn_ptr != 0
      && reg_referenced_p (x, PATTERN (*insn_ptr)))
    *insn_ptr = 0;
}

/* Return true if there is true register dependence between vr4130_last_insn
   and INSN.  */

static bool
vr4130_true_reg_dependence_p (rtx insn)
{
  note_stores (PATTERN (vr4130_last_insn),
               vr4130_true_reg_dependence_p_1, &insn);
  return insn == 0;
}

/* A TUNE_MIPS4130 helper function.  Given that INSN1 is at the head of
   the ready queue and that INSN2 is the instruction after it, return
   true if it is worth promoting INSN2 ahead of INSN1.  Look for cases
   in which INSN1 and INSN2 can probably issue in parallel, but for
   which (INSN2, INSN1) should be less sensitive to instruction
   alignment than (INSN1, INSN2).  See 4130.md for more details.  */

static bool
vr4130_swap_insns_p (rtx insn1, rtx insn2)
{
  sd_iterator_def sd_it;
  dep_t dep;

  /* Check for the following case:

     1) there is some other instruction X with an anti dependence on INSN1;
     2) X has a higher priority than INSN2; and
     3) X is an arithmetic instruction (and thus has no unit restrictions).

     If INSN1 is the last instruction blocking X, it would better to
     choose (INSN1, X) over (INSN2, INSN1).  */
  FOR_EACH_DEP (insn1, SD_LIST_FORW, sd_it, dep)
    if (DEP_TYPE (dep) == REG_DEP_ANTI
        && INSN_PRIORITY (DEP_CON (dep)) > INSN_PRIORITY (insn2)
        && recog_memoized (DEP_CON (dep)) >= 0
        && get_attr_vr4130_class (DEP_CON (dep)) == VR4130_CLASS_ALU)
      return false;

  if (vr4130_last_insn != 0
      && recog_memoized (insn1) >= 0
      && recog_memoized (insn2) >= 0)
    {
      /* See whether INSN1 and INSN2 use different execution units,
         or if they are both ALU-type instructions.  If so, they can
         probably execute in parallel.  */
      enum attr_vr4130_class class1 = get_attr_vr4130_class (insn1);
      enum attr_vr4130_class class2 = get_attr_vr4130_class (insn2);
      if (class1 != class2 || class1 == VR4130_CLASS_ALU)
        {
          /* If only one of the instructions has a dependence on
             vr4130_last_insn, prefer to schedule the other one first.  */
          bool dep1 = vr4130_true_reg_dependence_p (insn1);
          bool dep2 = vr4130_true_reg_dependence_p (insn2);
          if (dep1 != dep2)
            return dep1;

          /* Prefer to schedule INSN2 ahead of INSN1 if vr4130_last_insn
             is not an ALU-type instruction and if INSN1 uses the same
             execution unit.  (Note that if this condition holds, we already
             know that INSN2 uses a different execution unit.)  */
          if (class1 != VR4130_CLASS_ALU
              && recog_memoized (vr4130_last_insn) >= 0
              && class1 == get_attr_vr4130_class (vr4130_last_insn))
            return true;
        }
    }
  return false;
}

/* A TUNE_MIPS4130 helper function.  (READY, NREADY) describes a ready
   queue with at least two instructions.  Swap the first two if
   vr4130_swap_insns_p says that it could be worthwhile.  */

static void
vr4130_reorder (rtx *ready, int nready)
{
  if (vr4130_swap_insns_p (ready[nready - 1], ready[nready - 2]))
    mips_promote_ready (ready, nready - 2, nready - 1);
}
\f
/* Record whether last 74k AGEN instruction was a load or store.  */

static enum attr_type mips_last_74k_agen_insn = TYPE_UNKNOWN;

/* Initialize mips_last_74k_agen_insn from INSN.  A null argument
   resets to TYPE_UNKNOWN state.  */

static void
mips_74k_agen_init (rtx insn)
{
  if (!insn || !NONJUMP_INSN_P (insn))
    mips_last_74k_agen_insn = TYPE_UNKNOWN;
  else if (USEFUL_INSN_P (insn))
    {
      enum attr_type type = get_attr_type (insn);
      if (type == TYPE_LOAD || type == TYPE_STORE)
        mips_last_74k_agen_insn = type;
    }
}

/* A TUNE_74K helper function.  The 74K AGEN pipeline likes multiple
   loads to be grouped together, and multiple stores to be grouped
   together.  Swap things around in the ready queue to make this happen.  */

static void
mips_74k_agen_reorder (rtx *ready, int nready)
{
  int i;
  int store_pos, load_pos;

  store_pos = -1;
  load_pos = -1;

  for (i = nready - 1; i >= 0; i--)
    {
      rtx insn = ready[i];
      if (USEFUL_INSN_P (insn))
        switch (get_attr_type (insn))
          {
          case TYPE_STORE:
            if (store_pos == -1)
              store_pos = i;
            break;

          case TYPE_LOAD:
            if (load_pos == -1)
              load_pos = i;
            break;

          default:
            break;
          }
    }

  if (load_pos == -1 || store_pos == -1)
    return;

  switch (mips_last_74k_agen_insn)
    {
    case TYPE_UNKNOWN:
      /* Prefer to schedule loads since they have a higher latency.  */
    case TYPE_LOAD:
      /* Swap loads to the front of the queue.  */
      mips_maybe_swap_ready (ready, load_pos, store_pos, 4);
      break;
    case TYPE_STORE:
      /* Swap stores to the front of the queue.  */
      mips_maybe_swap_ready (ready, store_pos, load_pos, 4);
      break;
    default:
      break;
    }
}
\f
/* Implement TARGET_SCHED_INIT.  */

static void
mips_sched_init (FILE *file ATTRIBUTE_UNUSED, int verbose ATTRIBUTE_UNUSED,
                 int max_ready ATTRIBUTE_UNUSED)
{
  mips_macc_chains_last_hilo = 0;
  vr4130_last_insn = 0;
  mips_74k_agen_init (NULL_RTX);
}

/* Implement TARGET_SCHED_REORDER and TARG_SCHED_REORDER2.  */

static int
mips_sched_reorder (FILE *file ATTRIBUTE_UNUSED, int verbose ATTRIBUTE_UNUSED,
                    rtx *ready, int *nreadyp, int cycle ATTRIBUTE_UNUSED)
{
  if (!reload_completed
      && TUNE_MACC_CHAINS
      && *nreadyp > 0)
    mips_macc_chains_reorder (ready, *nreadyp);
  if (reload_completed
      && TUNE_MIPS4130
      && !TARGET_VR4130_ALIGN
      && *nreadyp > 1)
    vr4130_reorder (ready, *nreadyp);
  if (TUNE_74K)
    mips_74k_agen_reorder (ready, *nreadyp);
  return mips_issue_rate ();
}

/* Implement TARGET_SCHED_VARIABLE_ISSUE.  */

static int
mips_variable_issue (FILE *file ATTRIBUTE_UNUSED, int verbose ATTRIBUTE_UNUSED,
                     rtx insn, int more)
{
  if (TUNE_74K)
    mips_74k_agen_init (insn);
  switch (GET_CODE (PATTERN (insn)))
    {
    case USE:
    case CLOBBER:
      /* Don't count USEs and CLOBBERs against the issue rate.  */
      break;

    default:
      more--;
      if (!reload_completed && TUNE_MACC_CHAINS)
        mips_macc_chains_record (insn);
      vr4130_last_insn = insn;
      break;
    }
  return more;
}
\f
/* Given that we have an rtx of the form (prefetch ... WRITE LOCALITY),
   return the first operand of the associated "pref" or "prefx" insn.  */

rtx
mips_prefetch_cookie (rtx write, rtx locality)
{
  /* store_streamed / load_streamed.  */
  if (INTVAL (locality) <= 0)
    return GEN_INT (INTVAL (write) + 4);

  /* store / load.  */
  if (INTVAL (locality) <= 2)
    return write;

  /* store_retained / load_retained.  */
  return GEN_INT (INTVAL (write) + 6);
}
\f
/* MIPS builtin function support. */

struct builtin_description
{
  /* The code of the main .md file instruction.  See mips_builtin_type
     for more information.  */
  enum insn_code icode;

  /* The floating-point comparison code to use with ICODE, if any.  */
  enum mips_fp_condition cond;

  /* The name of the builtin function.  */
  const char *name;

  /* Specifies how the function should be expanded.  */
  enum mips_builtin_type builtin_type;

  /* The function's prototype.  */
  enum mips_function_type function_type;

  /* The target flags required for this function.  */
  int target_flags;
};

/* Define a MIPS_BUILTIN_DIRECT function for instruction CODE_FOR_mips_<INSN>.
   FUNCTION_TYPE and TARGET_FLAGS are builtin_description fields.  */
#define DIRECT_BUILTIN(INSN, FUNCTION_TYPE, TARGET_FLAGS)               \
  { CODE_FOR_mips_ ## INSN, 0, "__builtin_mips_" #INSN,                 \
    MIPS_BUILTIN_DIRECT, FUNCTION_TYPE, TARGET_FLAGS }

/* Define __builtin_mips_<INSN>_<COND>_{s,d}, both of which require
   TARGET_FLAGS.  */
#define CMP_SCALAR_BUILTINS(INSN, COND, TARGET_FLAGS)                   \
  { CODE_FOR_mips_ ## INSN ## _cond_s, MIPS_FP_COND_ ## COND,           \
    "__builtin_mips_" #INSN "_" #COND "_s",                             \
    MIPS_BUILTIN_CMP_SINGLE, MIPS_INT_FTYPE_SF_SF, TARGET_FLAGS },      \
  { CODE_FOR_mips_ ## INSN ## _cond_d, MIPS_FP_COND_ ## COND,           \
    "__builtin_mips_" #INSN "_" #COND "_d",                             \
    MIPS_BUILTIN_CMP_SINGLE, MIPS_INT_FTYPE_DF_DF, TARGET_FLAGS }

/* Define __builtin_mips_{any,all,upper,lower}_<INSN>_<COND>_ps.
   The lower and upper forms require TARGET_FLAGS while the any and all
   forms require MASK_MIPS3D.  */
#define CMP_PS_BUILTINS(INSN, COND, TARGET_FLAGS)                       \
  { CODE_FOR_mips_ ## INSN ## _cond_ps, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_any_" #INSN "_" #COND "_ps",                        \
    MIPS_BUILTIN_CMP_ANY, MIPS_INT_FTYPE_V2SF_V2SF, MASK_MIPS3D },      \
  { CODE_FOR_mips_ ## INSN ## _cond_ps, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_all_" #INSN "_" #COND "_ps",                        \
    MIPS_BUILTIN_CMP_ALL, MIPS_INT_FTYPE_V2SF_V2SF, MASK_MIPS3D },      \
  { CODE_FOR_mips_ ## INSN ## _cond_ps, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_lower_" #INSN "_" #COND "_ps",                      \
    MIPS_BUILTIN_CMP_LOWER, MIPS_INT_FTYPE_V2SF_V2SF, TARGET_FLAGS },   \
  { CODE_FOR_mips_ ## INSN ## _cond_ps, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_upper_" #INSN "_" #COND "_ps",                      \
    MIPS_BUILTIN_CMP_UPPER, MIPS_INT_FTYPE_V2SF_V2SF, TARGET_FLAGS }

/* Define __builtin_mips_{any,all}_<INSN>_<COND>_4s.  The functions
   require MASK_MIPS3D.  */
#define CMP_4S_BUILTINS(INSN, COND)                                     \
  { CODE_FOR_mips_ ## INSN ## _cond_4s, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_any_" #INSN "_" #COND "_4s",                        \
    MIPS_BUILTIN_CMP_ANY, MIPS_INT_FTYPE_V2SF_V2SF_V2SF_V2SF,           \
    MASK_MIPS3D },                                                      \
  { CODE_FOR_mips_ ## INSN ## _cond_4s, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_all_" #INSN "_" #COND "_4s",                        \
    MIPS_BUILTIN_CMP_ALL, MIPS_INT_FTYPE_V2SF_V2SF_V2SF_V2SF,           \
    MASK_MIPS3D }

/* Define __builtin_mips_mov{t,f}_<INSN>_<COND>_ps.  The comparison
   instruction requires TARGET_FLAGS.  */
#define MOVTF_BUILTINS(INSN, COND, TARGET_FLAGS)                        \
  { CODE_FOR_mips_ ## INSN ## _cond_ps, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_movt_" #INSN "_" #COND "_ps",                       \
    MIPS_BUILTIN_MOVT, MIPS_V2SF_FTYPE_V2SF_V2SF_V2SF_V2SF,             \
    TARGET_FLAGS },                                                     \
  { CODE_FOR_mips_ ## INSN ## _cond_ps, MIPS_FP_COND_ ## COND,          \
    "__builtin_mips_movf_" #INSN "_" #COND "_ps",                       \
    MIPS_BUILTIN_MOVF, MIPS_V2SF_FTYPE_V2SF_V2SF_V2SF_V2SF,             \
    TARGET_FLAGS }

/* Define all the builtins related to c.cond.fmt condition COND.  */
#define CMP_BUILTINS(COND)                                              \
  MOVTF_BUILTINS (c, COND, MASK_PAIRED_SINGLE_FLOAT),                   \
  MOVTF_BUILTINS (cabs, COND, MASK_MIPS3D),                             \
  CMP_SCALAR_BUILTINS (cabs, COND, MASK_MIPS3D),                        \
  CMP_PS_BUILTINS (c, COND, MASK_PAIRED_SINGLE_FLOAT),                  \
  CMP_PS_BUILTINS (cabs, COND, MASK_MIPS3D),                            \
  CMP_4S_BUILTINS (c, COND),                                            \
  CMP_4S_BUILTINS (cabs, COND)

static const struct builtin_description mips_bdesc[] =
{
  DIRECT_BUILTIN (pll_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (pul_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (plu_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (puu_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (cvt_ps_s, MIPS_V2SF_FTYPE_SF_SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (cvt_s_pl, MIPS_SF_FTYPE_V2SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (cvt_s_pu, MIPS_SF_FTYPE_V2SF, MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (abs_ps, MIPS_V2SF_FTYPE_V2SF, MASK_PAIRED_SINGLE_FLOAT),

  DIRECT_BUILTIN (alnv_ps, MIPS_V2SF_FTYPE_V2SF_V2SF_INT,
                  MASK_PAIRED_SINGLE_FLOAT),
  DIRECT_BUILTIN (addr_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_MIPS3D),
  DIRECT_BUILTIN (mulr_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_MIPS3D),
  DIRECT_BUILTIN (cvt_pw_ps, MIPS_V2SF_FTYPE_V2SF, MASK_MIPS3D),
  DIRECT_BUILTIN (cvt_ps_pw, MIPS_V2SF_FTYPE_V2SF, MASK_MIPS3D),

  DIRECT_BUILTIN (recip1_s, MIPS_SF_FTYPE_SF, MASK_MIPS3D),
  DIRECT_BUILTIN (recip1_d, MIPS_DF_FTYPE_DF, MASK_MIPS3D),
  DIRECT_BUILTIN (recip1_ps, MIPS_V2SF_FTYPE_V2SF, MASK_MIPS3D),
  DIRECT_BUILTIN (recip2_s, MIPS_SF_FTYPE_SF_SF, MASK_MIPS3D),
  DIRECT_BUILTIN (recip2_d, MIPS_DF_FTYPE_DF_DF, MASK_MIPS3D),
  DIRECT_BUILTIN (recip2_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_MIPS3D),

  DIRECT_BUILTIN (rsqrt1_s, MIPS_SF_FTYPE_SF, MASK_MIPS3D),
  DIRECT_BUILTIN (rsqrt1_d, MIPS_DF_FTYPE_DF, MASK_MIPS3D),
  DIRECT_BUILTIN (rsqrt1_ps, MIPS_V2SF_FTYPE_V2SF, MASK_MIPS3D),
  DIRECT_BUILTIN (rsqrt2_s, MIPS_SF_FTYPE_SF_SF, MASK_MIPS3D),
  DIRECT_BUILTIN (rsqrt2_d, MIPS_DF_FTYPE_DF_DF, MASK_MIPS3D),
  DIRECT_BUILTIN (rsqrt2_ps, MIPS_V2SF_FTYPE_V2SF_V2SF, MASK_MIPS3D),

  MIPS_FP_CONDITIONS (CMP_BUILTINS)
};

/* Builtin functions for the SB-1 processor.  */

#define CODE_FOR_mips_sqrt_ps CODE_FOR_sqrtv2sf2

static const struct builtin_description sb1_bdesc[] =
{
  DIRECT_BUILTIN (sqrt_ps, MIPS_V2SF_FTYPE_V2SF, MASK_PAIRED_SINGLE_FLOAT)
};

/* Builtin functions for DSP ASE.  */

#define CODE_FOR_mips_addq_ph CODE_FOR_addv2hi3
#define CODE_FOR_mips_addu_qb CODE_FOR_addv4qi3
#define CODE_FOR_mips_subq_ph CODE_FOR_subv2hi3
#define CODE_FOR_mips_subu_qb CODE_FOR_subv4qi3
#define CODE_FOR_mips_mul_ph CODE_FOR_mulv2hi3

/* Define a MIPS_BUILTIN_DIRECT_NO_TARGET function for instruction
   CODE_FOR_mips_<INSN>.  FUNCTION_TYPE and TARGET_FLAGS are
   builtin_description fields.  */
#define DIRECT_NO_TARGET_BUILTIN(INSN, FUNCTION_TYPE, TARGET_FLAGS)     \
  { CODE_FOR_mips_ ## INSN, 0, "__builtin_mips_" #INSN,                 \
    MIPS_BUILTIN_DIRECT_NO_TARGET, FUNCTION_TYPE, TARGET_FLAGS }

/* Define __builtin_mips_bposge<VALUE>.  <VALUE> is 32 for the MIPS32 DSP
   branch instruction.  TARGET_FLAGS is a builtin_description field.  */
#define BPOSGE_BUILTIN(VALUE, TARGET_FLAGS)                             \
  { CODE_FOR_mips_bposge, 0, "__builtin_mips_bposge" #VALUE,            \
    MIPS_BUILTIN_BPOSGE ## VALUE, MIPS_SI_FTYPE_VOID, TARGET_FLAGS }

static const struct builtin_description dsp_bdesc[] =
{
  DIRECT_BUILTIN (addq_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (addq_s_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (addq_s_w, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (addu_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (addu_s_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (subq_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (subq_s_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (subq_s_w, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (subu_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (subu_s_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (addsc, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (addwc, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (modsub, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (raddu_w_qb, MIPS_SI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (absq_s_ph, MIPS_V2HI_FTYPE_V2HI, MASK_DSP),
  DIRECT_BUILTIN (absq_s_w, MIPS_SI_FTYPE_SI, MASK_DSP),
  DIRECT_BUILTIN (precrq_qb_ph, MIPS_V4QI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (precrq_ph_w, MIPS_V2HI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (precrq_rs_ph_w, MIPS_V2HI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (precrqu_s_qb_ph, MIPS_V4QI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (preceq_w_phl, MIPS_SI_FTYPE_V2HI, MASK_DSP),
  DIRECT_BUILTIN (preceq_w_phr, MIPS_SI_FTYPE_V2HI, MASK_DSP),
  DIRECT_BUILTIN (precequ_ph_qbl, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (precequ_ph_qbr, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (precequ_ph_qbla, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (precequ_ph_qbra, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (preceu_ph_qbl, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (preceu_ph_qbr, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (preceu_ph_qbla, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (preceu_ph_qbra, MIPS_V2HI_FTYPE_V4QI, MASK_DSP),
  DIRECT_BUILTIN (shll_qb, MIPS_V4QI_FTYPE_V4QI_SI, MASK_DSP),
  DIRECT_BUILTIN (shll_ph, MIPS_V2HI_FTYPE_V2HI_SI, MASK_DSP),
  DIRECT_BUILTIN (shll_s_ph, MIPS_V2HI_FTYPE_V2HI_SI, MASK_DSP),
  DIRECT_BUILTIN (shll_s_w, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (shrl_qb, MIPS_V4QI_FTYPE_V4QI_SI, MASK_DSP),
  DIRECT_BUILTIN (shra_ph, MIPS_V2HI_FTYPE_V2HI_SI, MASK_DSP),
  DIRECT_BUILTIN (shra_r_ph, MIPS_V2HI_FTYPE_V2HI_SI, MASK_DSP),
  DIRECT_BUILTIN (shra_r_w, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (muleu_s_ph_qbl, MIPS_V2HI_FTYPE_V4QI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (muleu_s_ph_qbr, MIPS_V2HI_FTYPE_V4QI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (mulq_rs_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (muleq_s_w_phl, MIPS_SI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (muleq_s_w_phr, MIPS_SI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (bitrev, MIPS_SI_FTYPE_SI, MASK_DSP),
  DIRECT_BUILTIN (insv, MIPS_SI_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (repl_qb, MIPS_V4QI_FTYPE_SI, MASK_DSP),
  DIRECT_BUILTIN (repl_ph, MIPS_V2HI_FTYPE_SI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (cmpu_eq_qb, MIPS_VOID_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (cmpu_lt_qb, MIPS_VOID_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (cmpu_le_qb, MIPS_VOID_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (cmpgu_eq_qb, MIPS_SI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (cmpgu_lt_qb, MIPS_SI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (cmpgu_le_qb, MIPS_SI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (cmp_eq_ph, MIPS_VOID_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (cmp_lt_ph, MIPS_VOID_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (cmp_le_ph, MIPS_VOID_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (pick_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (pick_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (packrl_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSP),
  DIRECT_NO_TARGET_BUILTIN (wrdsp, MIPS_VOID_FTYPE_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (rddsp, MIPS_SI_FTYPE_SI, MASK_DSP),
  DIRECT_BUILTIN (lbux, MIPS_SI_FTYPE_POINTER_SI, MASK_DSP),
  DIRECT_BUILTIN (lhx, MIPS_SI_FTYPE_POINTER_SI, MASK_DSP),
  DIRECT_BUILTIN (lwx, MIPS_SI_FTYPE_POINTER_SI, MASK_DSP),
  BPOSGE_BUILTIN (32, MASK_DSP),

  /* The following are for the MIPS DSP ASE REV 2.  */
  DIRECT_BUILTIN (absq_s_qb, MIPS_V4QI_FTYPE_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (addu_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (addu_s_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (adduh_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (adduh_r_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (append, MIPS_SI_FTYPE_SI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (balign, MIPS_SI_FTYPE_SI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (cmpgdu_eq_qb, MIPS_SI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (cmpgdu_lt_qb, MIPS_SI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (cmpgdu_le_qb, MIPS_SI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (mul_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (mul_s_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (mulq_rs_w, MIPS_SI_FTYPE_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (mulq_s_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (mulq_s_w, MIPS_SI_FTYPE_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (precr_qb_ph, MIPS_V4QI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (precr_sra_ph_w, MIPS_V2HI_FTYPE_SI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (precr_sra_r_ph_w, MIPS_V2HI_FTYPE_SI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (prepend, MIPS_SI_FTYPE_SI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (shra_qb, MIPS_V4QI_FTYPE_V4QI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (shra_r_qb, MIPS_V4QI_FTYPE_V4QI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (shrl_ph, MIPS_V2HI_FTYPE_V2HI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (subu_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (subu_s_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (subuh_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (subuh_r_qb, MIPS_V4QI_FTYPE_V4QI_V4QI, MASK_DSPR2),
  DIRECT_BUILTIN (addqh_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (addqh_r_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (addqh_w, MIPS_SI_FTYPE_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (addqh_r_w, MIPS_SI_FTYPE_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (subqh_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (subqh_r_ph, MIPS_V2HI_FTYPE_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (subqh_w, MIPS_SI_FTYPE_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (subqh_r_w, MIPS_SI_FTYPE_SI_SI, MASK_DSPR2)
};

static const struct builtin_description dsp_32only_bdesc[] =
{
  DIRECT_BUILTIN (dpau_h_qbl, MIPS_DI_FTYPE_DI_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (dpau_h_qbr, MIPS_DI_FTYPE_DI_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (dpsu_h_qbl, MIPS_DI_FTYPE_DI_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (dpsu_h_qbr, MIPS_DI_FTYPE_DI_V4QI_V4QI, MASK_DSP),
  DIRECT_BUILTIN (dpaq_s_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (dpsq_s_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (mulsaq_s_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (dpaq_sa_l_w, MIPS_DI_FTYPE_DI_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (dpsq_sa_l_w, MIPS_DI_FTYPE_DI_SI_SI, MASK_DSP),
  DIRECT_BUILTIN (maq_s_w_phl, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (maq_s_w_phr, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (maq_sa_w_phl, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (maq_sa_w_phr, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSP),
  DIRECT_BUILTIN (extr_w, MIPS_SI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (extr_r_w, MIPS_SI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (extr_rs_w, MIPS_SI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (extr_s_h, MIPS_SI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (extp, MIPS_SI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (extpdp, MIPS_SI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (shilo, MIPS_DI_FTYPE_DI_SI, MASK_DSP),
  DIRECT_BUILTIN (mthlip, MIPS_DI_FTYPE_DI_SI, MASK_DSP),

  /* The following are for the MIPS DSP ASE REV 2.  */
  DIRECT_BUILTIN (dpa_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (dps_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (madd, MIPS_DI_FTYPE_DI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (maddu, MIPS_DI_FTYPE_DI_USI_USI, MASK_DSPR2),
  DIRECT_BUILTIN (msub, MIPS_DI_FTYPE_DI_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (msubu, MIPS_DI_FTYPE_DI_USI_USI, MASK_DSPR2),
  DIRECT_BUILTIN (mulsa_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (mult, MIPS_DI_FTYPE_SI_SI, MASK_DSPR2),
  DIRECT_BUILTIN (multu, MIPS_DI_FTYPE_USI_USI, MASK_DSPR2),
  DIRECT_BUILTIN (dpax_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (dpsx_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (dpaqx_s_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (dpaqx_sa_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (dpsqx_s_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2),
  DIRECT_BUILTIN (dpsqx_sa_w_ph, MIPS_DI_FTYPE_DI_V2HI_V2HI, MASK_DSPR2)
};

/* This helps provide a mapping from builtin function codes to bdesc
   arrays.  */

struct bdesc_map
{
  /* The builtin function table that this entry describes.  */
  const struct builtin_description *bdesc;

  /* The number of entries in the builtin function table.  */
  unsigned int size;

  /* The target processor that supports these builtin functions.
     PROCESSOR_MAX means we enable them for all processors.  */
  enum processor_type proc;

  /* If the target has these flags, this builtin function table
     will not be supported.  */
  int unsupported_target_flags;
};

static const struct bdesc_map bdesc_arrays[] =
{
  { mips_bdesc, ARRAY_SIZE (mips_bdesc), PROCESSOR_MAX, 0 },
  { sb1_bdesc, ARRAY_SIZE (sb1_bdesc), PROCESSOR_SB1, 0 },
  { dsp_bdesc, ARRAY_SIZE (dsp_bdesc), PROCESSOR_MAX, 0 },
  { dsp_32only_bdesc, ARRAY_SIZE (dsp_32only_bdesc), PROCESSOR_MAX,
    MASK_64BIT }
};

/* MODE is a vector mode whose elements have type TYPE.  Return the type
   of the vector itself.  */

static tree
mips_builtin_vector_type (tree type, enum machine_mode mode)
{
  static tree types[(int) MAX_MACHINE_MODE];

  if (types[(int) mode] == NULL_TREE)
    types[(int) mode] = build_vector_type_for_mode (type, mode);
  return types[(int) mode];
}

/* Source-level argument types.  */
#define MIPS_ATYPE_VOID void_type_node
#define MIPS_ATYPE_INT integer_type_node
#define MIPS_ATYPE_POINTER ptr_type_node

/* Standard mode-based argument types.  */
#define MIPS_ATYPE_SI intSI_type_node
#define MIPS_ATYPE_USI unsigned_intSI_type_node
#define MIPS_ATYPE_DI intDI_type_node
#define MIPS_ATYPE_SF float_type_node
#define MIPS_ATYPE_DF double_type_node

/* Vector argument types.  */
#define MIPS_ATYPE_V2SF mips_builtin_vector_type (float_type_node, V2SFmode)
#define MIPS_ATYPE_V2HI mips_builtin_vector_type (intHI_type_node, V2HImode)
#define MIPS_ATYPE_V4QI mips_builtin_vector_type (intQI_type_node, V4QImode)

/* MIPS_FTYPE_ATYPESN takes N MIPS_FTYPES-like type codes and lists
   their associated MIPS_ATYPEs.  */
#define MIPS_FTYPE_ATYPES1(A, B) \
  MIPS_ATYPE_##A, MIPS_ATYPE_##B

#define MIPS_FTYPE_ATYPES2(A, B, C) \
  MIPS_ATYPE_##A, MIPS_ATYPE_##B, MIPS_ATYPE_##C

#define MIPS_FTYPE_ATYPES3(A, B, C, D) \
  MIPS_ATYPE_##A, MIPS_ATYPE_##B, MIPS_ATYPE_##C, MIPS_ATYPE_##D

#define MIPS_FTYPE_ATYPES4(A, B, C, D, E) \
  MIPS_ATYPE_##A, MIPS_ATYPE_##B, MIPS_ATYPE_##C, MIPS_ATYPE_##D, \
  MIPS_ATYPE_##E

/* Return the function type associated with function prototype TYPE.  */

static tree
mips_build_function_type (enum mips_function_type type)
{
  static tree types[(int) MIPS_MAX_FTYPE_MAX];

  if (types[(int) type] == NULL_TREE)
    switch (type)
      {
#define DEF_MIPS_FTYPE(NUM, ARGS)                                       \
  case MIPS_FTYPE_NAME##NUM ARGS:                                       \
    types[(int) type]                                                   \
      = build_function_type_list (MIPS_FTYPE_ATYPES##NUM ARGS,          \
                                  NULL_TREE);                           \
    break;
#include "config/mips/mips-ftypes.def"
#undef DEF_MIPS_FTYPE
      default:
        gcc_unreachable ();
      }

  return types[(int) type];
}

/* Init builtin functions.  This is called from TARGET_INIT_BUILTIN.  */

static void
mips_init_builtins (void)
{
  const struct builtin_description *d;
  const struct bdesc_map *m;
  unsigned int offset;

  /* Iterate through all of the bdesc arrays, initializing all of the
     builtin functions.  */

  offset = 0;
  for (m = bdesc_arrays; m < &bdesc_arrays[ARRAY_SIZE (bdesc_arrays)]; m++)
    {
      if ((m->proc == PROCESSOR_MAX || (m->proc == mips_arch))
          && (m->unsupported_target_flags & target_flags) == 0)
        for (d = m->bdesc; d < &m->bdesc[m->size]; d++)
          if ((d->target_flags & target_flags) == d->target_flags)
            add_builtin_function (d->name,
                                  mips_build_function_type (d->function_type),
                                  d - m->bdesc + offset,
                                  BUILT_IN_MD, NULL, NULL);
      offset += m->size;
    }
}

/* Take the argument ARGNUM of the arglist of EXP and convert it into a form
   suitable for input operand OP of instruction ICODE.  Return the value.  */

static rtx
mips_prepare_builtin_arg (enum insn_code icode,
                          unsigned int op, tree exp, unsigned int argnum)
{
  rtx value;
  enum machine_mode mode;

  value = expand_normal (CALL_EXPR_ARG (exp, argnum));
  mode = insn_data[icode].operand[op].mode;
  if (!insn_data[icode].operand[op].predicate (value, mode))
    {
      value = copy_to_mode_reg (mode, value);
      /* Check the predicate again.  */
      if (!insn_data[icode].operand[op].predicate (value, mode))
        {
          error ("invalid argument to builtin function");
          return const0_rtx;
        }
    }

  return value;
}

/* Return an rtx suitable for output operand OP of instruction ICODE.
   If TARGET is non-null, try to use it where possible.  */

static rtx
mips_prepare_builtin_target (enum insn_code icode, unsigned int op, rtx target)
{
  enum machine_mode mode;

  mode = insn_data[icode].operand[op].mode;
  if (target == 0 || !insn_data[icode].operand[op].predicate (target, mode))
    target = gen_reg_rtx (mode);

  return target;
}

/* Expand a MIPS_BUILTIN_DIRECT function.  ICODE is the code of the
   .md pattern and CALL is the function expr with arguments.  TARGET,
   if nonnull, suggests a good place to put the result.
   HAS_TARGET indicates the function must return something.  */

static rtx
mips_expand_builtin_direct (enum insn_code icode, rtx target, tree exp,
                            bool has_target)
{
  rtx ops[MAX_RECOG_OPERANDS];
  int i = 0;
  int j = 0;

  if (has_target)
    {
      /* We save target to ops[0].  */
      ops[0] = mips_prepare_builtin_target (icode, 0, target);
      i = 1;
    }

  /* We need to test if the arglist is not zero.  Some instructions have extra
     clobber registers.  */
  for (; i < insn_data[icode].n_operands && i <= call_expr_nargs (exp); i++, j++)
    ops[i] = mips_prepare_builtin_arg (icode, i, exp, j);

  switch (i)
    {
    case 2:
      emit_insn (GEN_FCN (icode) (ops[0], ops[1]));
      break;

    case 3:
      emit_insn (GEN_FCN (icode) (ops[0], ops[1], ops[2]));
      break;

    case 4:
      emit_insn (GEN_FCN (icode) (ops[0], ops[1], ops[2], ops[3]));
      break;

    default:
      gcc_unreachable ();
    }
  return target;
}

/* Expand a __builtin_mips_movt_*_ps() or __builtin_mips_movf_*_ps()
   function (TYPE says which).  EXP is the tree for the function
   function, ICODE is the instruction that should be used to compare
   the first two arguments, and COND is the condition it should test.
   TARGET, if nonnull, suggests a good place to put the result.  */

static rtx
mips_expand_builtin_movtf (enum mips_builtin_type type,
                           enum insn_code icode, enum mips_fp_condition cond,
                           rtx target, tree exp)
{
  rtx cmp_result, op0, op1;

  cmp_result = mips_prepare_builtin_target (icode, 0, 0);
  op0 = mips_prepare_builtin_arg (icode, 1, exp, 0);
  op1 = mips_prepare_builtin_arg (icode, 2, exp, 1);
  emit_insn (GEN_FCN (icode) (cmp_result, op0, op1, GEN_INT (cond)));

  icode = CODE_FOR_mips_cond_move_tf_ps;
  target = mips_prepare_builtin_target (icode, 0, target);
  if (type == MIPS_BUILTIN_MOVT)
    {
      op1 = mips_prepare_builtin_arg (icode, 2, exp, 2);
      op0 = mips_prepare_builtin_arg (icode, 1, exp, 3);
    }
  else
    {
      op0 = mips_prepare_builtin_arg (icode, 1, exp, 2);
      op1 = mips_prepare_builtin_arg (icode, 2, exp, 3);
    }
  emit_insn (gen_mips_cond_move_tf_ps (target, op0, op1, cmp_result));
  return target;
}

/* Move VALUE_IF_TRUE into TARGET if CONDITION is true; move VALUE_IF_FALSE
   into TARGET otherwise.  Return TARGET.  */

static rtx
mips_builtin_branch_and_move (rtx condition, rtx target,
                              rtx value_if_true, rtx value_if_false)
{
  rtx true_label, done_label;

  true_label = gen_label_rtx ();
  done_label = gen_label_rtx ();

  /* First assume that CONDITION is false.  */
  mips_emit_move (target, value_if_false);

  /* Branch to TRUE_LABEL if CONDITION is true and DONE_LABEL otherwise.  */
  emit_jump_insn (gen_condjump (condition, true_label));
  emit_jump_insn (gen_jump (done_label));
  emit_barrier ();

  /* Fix TARGET if CONDITION is true.  */
  emit_label (true_label);
  mips_emit_move (target, value_if_true);

  emit_label (done_label);
  return target;
}

/* Expand a comparison builtin of type BUILTIN_TYPE.  ICODE is the code
   of the comparison instruction and COND is the condition it should test.
   EXP is the function call and arguments and TARGET, if nonnull,
   suggests a good place to put the boolean result.  */

static rtx
mips_expand_builtin_compare (enum mips_builtin_type builtin_type,
                             enum insn_code icode, enum mips_fp_condition cond,
                             rtx target, tree exp)
{
  rtx offset, condition, cmp_result, ops[MAX_RECOG_OPERANDS];
  int i;
  int j = 0;

  if (target == 0 || GET_MODE (target) != SImode)
    target = gen_reg_rtx (SImode);

  /* Prepare the operands to the comparison.  */
  cmp_result = mips_prepare_builtin_target (icode, 0, 0);
  for (i = 1; i < insn_data[icode].n_operands - 1; i++, j++)
    ops[i] = mips_prepare_builtin_arg (icode, i, exp, j);

  switch (insn_data[icode].n_operands)
    {
    case 4:
      emit_insn (GEN_FCN (icode) (cmp_result, ops[1], ops[2], GEN_INT (cond)));
      break;

    case 6:
      emit_insn (GEN_FCN (icode) (cmp_result, ops[1], ops[2],
                                  ops[3], ops[4], GEN_INT (cond)));
      break;

    default:
      gcc_unreachable ();
    }

  /* If the comparison sets more than one register, we define the result
     to be 0 if all registers are false and -1 if all registers are true.
     The value of the complete result is indeterminate otherwise.  */
  switch (builtin_type)
    {
    case MIPS_BUILTIN_CMP_ALL:
      condition = gen_rtx_NE (VOIDmode, cmp_result, constm1_rtx);
      return mips_builtin_branch_and_move (condition, target,
                                           const0_rtx, const1_rtx);

    case MIPS_BUILTIN_CMP_UPPER:
    case MIPS_BUILTIN_CMP_LOWER:
      offset = GEN_INT (builtin_type == MIPS_BUILTIN_CMP_UPPER);
      condition = gen_single_cc (cmp_result, offset);
      return mips_builtin_branch_and_move (condition, target,
                                           const1_rtx, const0_rtx);

    default:
      condition = gen_rtx_NE (VOIDmode, cmp_result, const0_rtx);
      return mips_builtin_branch_and_move (condition, target,
                                           const1_rtx, const0_rtx);
    }
}

/* Expand a bposge builtin of type BUILTIN_TYPE.  TARGET, if nonnull,
   suggests a good place to put the boolean result.  */

static rtx
mips_expand_builtin_bposge (enum mips_builtin_type builtin_type, rtx target)
{
  rtx condition, cmp_result;
  int cmp_value;

  if (target == 0 || GET_MODE (target) != SImode)
    target = gen_reg_rtx (SImode);

  cmp_result = gen_rtx_REG (CCDSPmode, CCDSP_PO_REGNUM);

  if (builtin_type == MIPS_BUILTIN_BPOSGE32)
    cmp_value = 32;
  else
    gcc_assert (0);

  condition = gen_rtx_GE (VOIDmode, cmp_result, GEN_INT (cmp_value));
  return mips_builtin_branch_and_move (condition, target,
                                       const1_rtx, const0_rtx);
}

/* Expand builtin functions.  This is called from TARGET_EXPAND_BUILTIN.  */

static rtx
mips_expand_builtin (tree exp, rtx target, rtx subtarget ATTRIBUTE_UNUSED,
                     enum machine_mode mode ATTRIBUTE_UNUSED,
                     int ignore ATTRIBUTE_UNUSED)
{
  enum insn_code icode;
  enum mips_builtin_type type;
  tree fndecl;
  unsigned int fcode;
  const struct builtin_description *bdesc;
  const struct bdesc_map *m;

  fndecl = TREE_OPERAND (CALL_EXPR_FN (exp), 0);
  fcode = DECL_FUNCTION_CODE (fndecl);

  if (TARGET_MIPS16)
    {
      error ("built-in function %qs not supported for MIPS16",
             IDENTIFIER_POINTER (DECL_NAME (fndecl)));
      return const0_rtx;
    }

  bdesc = NULL;
  for (m = bdesc_arrays; m < &bdesc_arrays[ARRAY_SIZE (bdesc_arrays)]; m++)
    {
      if (fcode < m->size)
        {
          bdesc = m->bdesc;
          icode = bdesc[fcode].icode;
          type = bdesc[fcode].builtin_type;
          break;
        }
      fcode -= m->size;
    }
  if (bdesc == NULL)
    return 0;

  switch (type)
    {
    case MIPS_BUILTIN_DIRECT:
      return mips_expand_builtin_direct (icode, target, exp, true);

    case MIPS_BUILTIN_DIRECT_NO_TARGET:
      return mips_expand_builtin_direct (icode, target, exp, false);

    case MIPS_BUILTIN_MOVT:
    case MIPS_BUILTIN_MOVF:
      return mips_expand_builtin_movtf (type, icode, bdesc[fcode].cond,
                                        target, exp);

    case MIPS_BUILTIN_CMP_ANY:
    case MIPS_BUILTIN_CMP_ALL:
    case MIPS_BUILTIN_CMP_UPPER:
    case MIPS_BUILTIN_CMP_LOWER:
    case MIPS_BUILTIN_CMP_SINGLE:
      return mips_expand_builtin_compare (type, icode, bdesc[fcode].cond,
                                          target, exp);

    case MIPS_BUILTIN_BPOSGE32:
      return mips_expand_builtin_bposge (type, target);

    default:
      return 0;
    }
}
\f
/* An entry in the mips16 constant pool.  VALUE is the pool constant,
   MODE is its mode, and LABEL is the CODE_LABEL associated with it.  */

struct mips16_constant {
  struct mips16_constant *next;
  rtx value;
  rtx label;
  enum machine_mode mode;
};

/* Information about an incomplete mips16 constant pool.  FIRST is the
   first constant, HIGHEST_ADDRESS is the highest address that the first
   byte of the pool can have, and INSN_ADDRESS is the current instruction
   address.  */

struct mips16_constant_pool {
  struct mips16_constant *first;
  int highest_address;
  int insn_address;
};

/* Add constant VALUE to POOL and return its label.  MODE is the
   value's mode (used for CONST_INTs, etc.).  */

static rtx
add_constant (struct mips16_constant_pool *pool,
              rtx value, enum machine_mode mode)
{
  struct mips16_constant **p, *c;
  bool first_of_size_p;

  /* See whether the constant is already in the pool.  If so, return the
     existing label, otherwise leave P pointing to the place where the
     constant should be added.

     Keep the pool sorted in increasing order of mode size so that we can
     reduce the number of alignments needed.  */
  first_of_size_p = true;
  for (p = &pool->first; *p != 0; p = &(*p)->next)
    {
      if (mode == (*p)->mode && rtx_equal_p (value, (*p)->value))
        return (*p)->label;
      if (GET_MODE_SIZE (mode) < GET_MODE_SIZE ((*p)->mode))
        break;
      if (GET_MODE_SIZE (mode) == GET_MODE_SIZE ((*p)->mode))
        first_of_size_p = false;
    }

  /* In the worst case, the constant needed by the earliest instruction
     will end up at the end of the pool.  The entire pool must then be
     accessible from that instruction.

     When adding the first constant, set the pool's highest address to
     the address of the first out-of-range byte.  Adjust this address
     downwards each time a new constant is added.  */
  if (pool->first == 0)
    /* For pc-relative lw, addiu and daddiu instructions, the base PC value
       is the address of the instruction with the lowest two bits clear.
       The base PC value for ld has the lowest three bits clear.  Assume
       the worst case here.  */
    pool->highest_address = pool->insn_address - (UNITS_PER_WORD - 2) + 0x8000;
  pool->highest_address -= GET_MODE_SIZE (mode);
  if (first_of_size_p)
    /* Take into account the worst possible padding due to alignment.  */
    pool->highest_address -= GET_MODE_SIZE (mode) - 1;

  /* Create a new entry.  */
  c = (struct mips16_constant *) xmalloc (sizeof *c);
  c->value = value;
  c->mode = mode;
  c->label = gen_label_rtx ();
  c->next = *p;
  *p = c;

  return c->label;
}

/* Output constant VALUE after instruction INSN and return the last
   instruction emitted.  MODE is the mode of the constant.  */

static rtx
dump_constants_1 (enum machine_mode mode, rtx value, rtx insn)
{
  if (SCALAR_INT_MODE_P (mode)
      || ALL_SCALAR_FRACT_MODE_P (mode)
      || ALL_SCALAR_ACCUM_MODE_P (mode))
    {
      rtx size = GEN_INT (GET_MODE_SIZE (mode));
      return emit_insn_after (gen_consttable_int (value, size), insn);
    }

  if (SCALAR_FLOAT_MODE_P (mode))
    return emit_insn_after (gen_consttable_float (value), insn);

  if (VECTOR_MODE_P (mode))
    {
      int i;

      for (i = 0; i < CONST_VECTOR_NUNITS (value); i++)
        insn = dump_constants_1 (GET_MODE_INNER (mode),
                                 CONST_VECTOR_ELT (value, i), insn);
      return insn;
    }

  gcc_unreachable ();
}


/* Dump out the constants in CONSTANTS after INSN.  */

static void
dump_constants (struct mips16_constant *constants, rtx insn)
{
  struct mips16_constant *c, *next;
  int align;

  align = 0;
  for (c = constants; c != NULL; c = next)
    {
      /* If necessary, increase the alignment of PC.  */
      if (align < GET_MODE_SIZE (c->mode))
        {
          int align_log = floor_log2 (GET_MODE_SIZE (c->mode));
          insn = emit_insn_after (gen_align (GEN_INT (align_log)), insn);
        }
      align = GET_MODE_SIZE (c->mode);

      insn = emit_label_after (c->label, insn);
      insn = dump_constants_1 (c->mode, c->value, insn);

      next = c->next;
      free (c);
    }

  emit_barrier_after (insn);
}

/* Return the length of instruction INSN.  */

static int
mips16_insn_length (rtx insn)
{
  if (JUMP_P (insn))
    {
      rtx body = PATTERN (insn);
      if (GET_CODE (body) == ADDR_VEC)
        return GET_MODE_SIZE (GET_MODE (body)) * XVECLEN (body, 0);
      if (GET_CODE (body) == ADDR_DIFF_VEC)
        return GET_MODE_SIZE (GET_MODE (body)) * XVECLEN (body, 1);
    }
  return get_attr_length (insn);
}

/* If *X is a symbolic constant that refers to the constant pool, add
   the constant to POOL and rewrite *X to use the constant's label.  */

static void
mips16_rewrite_pool_constant (struct mips16_constant_pool *pool, rtx *x)
{
  rtx base, offset, label;

  split_const (*x, &base, &offset);
  if (GET_CODE (base) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (base))
    {
      label = add_constant (pool, get_pool_constant (base),
                            get_pool_mode (base));
      base = gen_rtx_LABEL_REF (Pmode, label);
      *x = mips_unspec_address_offset (base, offset, SYMBOL_PC_RELATIVE);
    }
}

/* This structure is used to communicate with mips16_rewrite_pool_refs.
   INSN is the instruction we're rewriting and POOL points to the current
   constant pool.  */
struct mips16_rewrite_pool_refs_info {
  rtx insn;
  struct mips16_constant_pool *pool;
};

/* Rewrite *X so that constant pool references refer to the constant's
   label instead.  DATA points to a mips16_rewrite_pool_refs_info
   structure.  */

static int
mips16_rewrite_pool_refs (rtx *x, void *data)
{
  struct mips16_rewrite_pool_refs_info *info = data;

  if (force_to_mem_operand (*x, Pmode))
    {
      rtx mem = force_const_mem (GET_MODE (*x), *x);
      validate_change (info->insn, x, mem, false);
    }

  if (MEM_P (*x))
    {
      mips16_rewrite_pool_constant (info->pool, &XEXP (*x, 0));
      return -1;
    }

  if (TARGET_MIPS16_TEXT_LOADS)
    mips16_rewrite_pool_constant (info->pool, x);

  return GET_CODE (*x) == CONST ? -1 : 0;
}

/* Build MIPS16 constant pools.  */

static void
mips16_lay_out_constants (void)
{
  struct mips16_constant_pool pool;
  struct mips16_rewrite_pool_refs_info info;
  rtx insn, barrier;

  if (!TARGET_MIPS16_PCREL_LOADS)
    return;

  barrier = 0;
  memset (&pool, 0, sizeof (pool));
  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
    {
      /* Rewrite constant pool references in INSN.  */
      if (INSN_P (insn))
        {
          info.insn = insn;
          info.pool = &pool;
          for_each_rtx (&PATTERN (insn), mips16_rewrite_pool_refs, &info);
        }

      pool.insn_address += mips16_insn_length (insn);

      if (pool.first != NULL)
        {
          /* If there are no natural barriers between the first user of
             the pool and the highest acceptable address, we'll need to
             create a new instruction to jump around the constant pool.
             In the worst case, this instruction will be 4 bytes long.

             If it's too late to do this transformation after INSN,
             do it immediately before INSN.  */
          if (barrier == 0 && pool.insn_address + 4 > pool.highest_address)
            {
              rtx label, jump;

              label = gen_label_rtx ();

              jump = emit_jump_insn_before (gen_jump (label), insn);
              JUMP_LABEL (jump) = label;
              LABEL_NUSES (label) = 1;
              barrier = emit_barrier_after (jump);

              emit_label_after (label, barrier);
              pool.insn_address += 4;
            }

          /* See whether the constant pool is now out of range of the first
             user.  If so, output the constants after the previous barrier.
             Note that any instructions between BARRIER and INSN (inclusive)
             will use negative offsets to refer to the pool.  */
          if (pool.insn_address > pool.highest_address)
            {
              dump_constants (pool.first, barrier);
              pool.first = NULL;
              barrier = 0;
            }
          else if (BARRIER_P (insn))
            barrier = insn;
        }
    }
  dump_constants (pool.first, get_last_insn ());
}
\f
/* A temporary variable used by for_each_rtx callbacks, etc.  */
static rtx mips_sim_insn;

/* A structure representing the state of the processor pipeline.
   Used by the mips_sim_* family of functions.  */
struct mips_sim {
  /* The maximum number of instructions that can be issued in a cycle.
     (Caches mips_issue_rate.)  */
  unsigned int issue_rate;

  /* The current simulation time.  */
  unsigned int time;

  /* How many more instructions can be issued in the current cycle.  */
  unsigned int insns_left;

  /* LAST_SET[X].INSN is the last instruction to set register X.
     LAST_SET[X].TIME is the time at which that instruction was issued.
     INSN is null if no instruction has yet set register X.  */
  struct {
    rtx insn;
    unsigned int time;
  } last_set[FIRST_PSEUDO_REGISTER];

  /* The pipeline's current DFA state.  */
  state_t dfa_state;
};

/* Reset STATE to the initial simulation state.  */

static void
mips_sim_reset (struct mips_sim *state)
{
  state->time = 0;
  state->insns_left = state->issue_rate;
  memset (&state->last_set, 0, sizeof (state->last_set));
  state_reset (state->dfa_state);
}

/* Initialize STATE before its first use.  DFA_STATE points to an
   allocated but uninitialized DFA state.  */

static void
mips_sim_init (struct mips_sim *state, state_t dfa_state)
{
  state->issue_rate = mips_issue_rate ();
  state->dfa_state = dfa_state;
  mips_sim_reset (state);
}

/* Advance STATE by one clock cycle.  */

static void
mips_sim_next_cycle (struct mips_sim *state)
{
  state->time++;
  state->insns_left = state->issue_rate;
  state_transition (state->dfa_state, 0);
}

/* Advance simulation state STATE until instruction INSN can read
   register REG.  */

static void
mips_sim_wait_reg (struct mips_sim *state, rtx insn, rtx reg)
{
  unsigned int i;

  for (i = 0; i < HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); i++)
    if (state->last_set[REGNO (reg) + i].insn != 0)
      {
        unsigned int t;

        t = state->last_set[REGNO (reg) + i].time;
        t += insn_latency (state->last_set[REGNO (reg) + i].insn, insn);
        while (state->time < t)
          mips_sim_next_cycle (state);
    }
}

/* A for_each_rtx callback.  If *X is a register, advance simulation state
   DATA until mips_sim_insn can read the register's value.  */

static int
mips_sim_wait_regs_2 (rtx *x, void *data)
{
  if (REG_P (*x))
    mips_sim_wait_reg (data, mips_sim_insn, *x);
  return 0;
}

/* Call mips_sim_wait_regs_2 (R, DATA) for each register R mentioned in *X.  */

static void
mips_sim_wait_regs_1 (rtx *x, void *data)
{
  for_each_rtx (x, mips_sim_wait_regs_2, data);
}

/* Advance simulation state STATE until all of INSN's register
   dependencies are satisfied.  */

static void
mips_sim_wait_regs (struct mips_sim *state, rtx insn)
{
  mips_sim_insn = insn;
  note_uses (&PATTERN (insn), mips_sim_wait_regs_1, state);
}

/* Advance simulation state STATE until the units required by
   instruction INSN are available.  */

static void
mips_sim_wait_units (struct mips_sim *state, rtx insn)
{
  state_t tmp_state;

  tmp_state = alloca (state_size ());
  while (state->insns_left == 0
         || (memcpy (tmp_state, state->dfa_state, state_size ()),
             state_transition (tmp_state, insn) >= 0))
    mips_sim_next_cycle (state);
}

/* Advance simulation state STATE until INSN is ready to issue.  */

static void
mips_sim_wait_insn (struct mips_sim *state, rtx insn)
{
  mips_sim_wait_regs (state, insn);
  mips_sim_wait_units (state, insn);
}

/* mips_sim_insn has just set X.  Update the LAST_SET array
   in simulation state DATA.  */

static void
mips_sim_record_set (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data)
{
  struct mips_sim *state;
  unsigned int i;

  state = data;
  if (REG_P (x))
    for (i = 0; i < HARD_REGNO_NREGS (REGNO (x), GET_MODE (x)); i++)
      {
        state->last_set[REGNO (x) + i].insn = mips_sim_insn;
        state->last_set[REGNO (x) + i].time = state->time;
      }
}

/* Issue instruction INSN in scheduler state STATE.  Assume that INSN
   can issue immediately (i.e., that mips_sim_wait_insn has already
   been called).  */

static void
mips_sim_issue_insn (struct mips_sim *state, rtx insn)
{
  state_transition (state->dfa_state, insn);
  state->insns_left--;

  mips_sim_insn = insn;
  note_stores (PATTERN (insn), mips_sim_record_set, state);
}

/* Simulate issuing a NOP in state STATE.  */

static void
mips_sim_issue_nop (struct mips_sim *state)
{
  if (state->insns_left == 0)
    mips_sim_next_cycle (state);
  state->insns_left--;
}

/* Update simulation state STATE so that it's ready to accept the instruction
   after INSN.  INSN should be part of the main rtl chain, not a member of a
   SEQUENCE.  */

static void
mips_sim_finish_insn (struct mips_sim *state, rtx insn)
{
  /* If INSN is a jump with an implicit delay slot, simulate a nop.  */
  if (JUMP_P (insn))
    mips_sim_issue_nop (state);

  switch (GET_CODE (SEQ_BEGIN (insn)))
    {
    case CODE_LABEL:
    case CALL_INSN:
      /* We can't predict the processor state after a call or label.  */
      mips_sim_reset (state);
      break;

    case JUMP_INSN:
      /* The delay slots of branch likely instructions are only executed
         when the branch is taken.  Therefore, if the caller has simulated
         the delay slot instruction, STATE does not really reflect the state
         of the pipeline for the instruction after the delay slot.  Also,
         branch likely instructions tend to incur a penalty when not taken,
         so there will probably be an extra delay between the branch and
         the instruction after the delay slot.  */
      if (INSN_ANNULLED_BRANCH_P (SEQ_BEGIN (insn)))
        mips_sim_reset (state);
      break;

    default:
      break;
    }
}
\f
/* The VR4130 pipeline issues aligned pairs of instructions together,
   but it stalls the second instruction if it depends on the first.
   In order to cut down the amount of logic required, this dependence
   check is not based on a full instruction decode.  Instead, any non-SPECIAL
   instruction is assumed to modify the register specified by bits 20-16
   (which is usually the "rt" field).

   In beq, beql, bne and bnel instructions, the rt field is actually an
   input, so we can end up with a false dependence between the branch
   and its delay slot.  If this situation occurs in instruction INSN,
   try to avoid it by swapping rs and rt.  */

static void
vr4130_avoid_branch_rt_conflict (rtx insn)
{
  rtx first, second;

  first = SEQ_BEGIN (insn);
  second = SEQ_END (insn);
  if (JUMP_P (first)
      && NONJUMP_INSN_P (second)
      && GET_CODE (PATTERN (first)) == SET
      && GET_CODE (SET_DEST (PATTERN (first))) == PC
      && GET_CODE (SET_SRC (PATTERN (first))) == IF_THEN_ELSE)
    {
      /* Check for the right kind of condition.  */
      rtx cond = XEXP (SET_SRC (PATTERN (first)), 0);
      if ((GET_CODE (cond) == EQ || GET_CODE (cond) == NE)
          && REG_P (XEXP (cond, 0))
          && REG_P (XEXP (cond, 1))
          && reg_referenced_p (XEXP (cond, 1), PATTERN (second))
          && !reg_referenced_p (XEXP (cond, 0), PATTERN (second)))
        {
          /* SECOND mentions the rt register but not the rs register.  */
          rtx tmp = XEXP (cond, 0);
          XEXP (cond, 0) = XEXP (cond, 1);
          XEXP (cond, 1) = tmp;
        }
    }
}

/* Implement -mvr4130-align.  Go through each basic block and simulate the
   processor pipeline.  If we find that a pair of instructions could execute
   in parallel, and the first of those instruction is not 8-byte aligned,
   insert a nop to make it aligned.  */

static void
vr4130_align_insns (void)
{
  struct mips_sim state;
  rtx insn, subinsn, last, last2, next;
  bool aligned_p;

  dfa_start ();

  /* LAST is the last instruction before INSN to have a nonzero length.
     LAST2 is the last such instruction before LAST.  */
  last = 0;
  last2 = 0;

  /* ALIGNED_P is true if INSN is known to be at an aligned address.  */
  aligned_p = true;

  mips_sim_init (&state, alloca (state_size ()));
  for (insn = get_insns (); insn != 0; insn = next)
    {
      unsigned int length;

      next = NEXT_INSN (insn);

      /* See the comment above vr4130_avoid_branch_rt_conflict for details.
         This isn't really related to the alignment pass, but we do it on
         the fly to avoid a separate instruction walk.  */
      vr4130_avoid_branch_rt_conflict (insn);

      if (USEFUL_INSN_P (insn))
        FOR_EACH_SUBINSN (subinsn, insn)
          {
            mips_sim_wait_insn (&state, subinsn);

            /* If we want this instruction to issue in parallel with the
               previous one, make sure that the previous instruction is
               aligned.  There are several reasons why this isn't worthwhile
               when the second instruction is a call:

                  - Calls are less likely to be performance critical,
                  - There's a good chance that the delay slot can execute
                    in parallel with the call.
                  - The return address would then be unaligned.

               In general, if we're going to insert a nop between instructions
               X and Y, it's better to insert it immediately after X.  That
               way, if the nop makes Y aligned, it will also align any labels
               between X and Y.  */
            if (state.insns_left != state.issue_rate
                && !CALL_P (subinsn))
              {
                if (subinsn == SEQ_BEGIN (insn) && aligned_p)
                  {
                    /* SUBINSN is the first instruction in INSN and INSN is
                       aligned.  We want to align the previous instruction
                       instead, so insert a nop between LAST2 and LAST.

                       Note that LAST could be either a single instruction
                       or a branch with a delay slot.  In the latter case,
                       LAST, like INSN, is already aligned, but the delay
                       slot must have some extra delay that stops it from
                       issuing at the same time as the branch.  We therefore
                       insert a nop before the branch in order to align its
                       delay slot.  */
                    emit_insn_after (gen_nop (), last2);
                    aligned_p = false;
                  }
                else if (subinsn != SEQ_BEGIN (insn) && !aligned_p)
                  {
                    /* SUBINSN is the delay slot of INSN, but INSN is
                       currently unaligned.  Insert a nop between
                       LAST and INSN to align it.  */
                    emit_insn_after (gen_nop (), last);
                    aligned_p = true;
                  }
              }
            mips_sim_issue_insn (&state, subinsn);
          }
      mips_sim_finish_insn (&state, insn);

      /* Update LAST, LAST2 and ALIGNED_P for the next instruction.  */
      length = get_attr_length (insn);
      if (length > 0)
        {
          /* If the instruction is an asm statement or multi-instruction
             mips.md patern, the length is only an estimate.  Insert an
             8 byte alignment after it so that the following instructions
             can be handled correctly.  */
          if (NONJUMP_INSN_P (SEQ_BEGIN (insn))
              && (recog_memoized (insn) < 0 || length >= 8))
            {
              next = emit_insn_after (gen_align (GEN_INT (3)), insn);
              next = NEXT_INSN (next);
              mips_sim_next_cycle (&state);
              aligned_p = true;
            }
          else if (length & 4)
            aligned_p = !aligned_p;
          last2 = last;
          last = insn;
        }

      /* See whether INSN is an aligned label.  */
      if (LABEL_P (insn) && label_to_alignment (insn) >= 3)
        aligned_p = true;
    }
  dfa_finish ();
}
\f
/* Subroutine of mips_reorg.  If there is a hazard between INSN
   and a previous instruction, avoid it by inserting nops after
   instruction AFTER.

   *DELAYED_REG and *HILO_DELAY describe the hazards that apply at
   this point.  If *DELAYED_REG is non-null, INSN must wait a cycle
   before using the value of that register.  *HILO_DELAY counts the
   number of instructions since the last hilo hazard (that is,
   the number of instructions since the last mflo or mfhi).

   After inserting nops for INSN, update *DELAYED_REG and *HILO_DELAY
   for the next instruction.

   LO_REG is an rtx for the LO register, used in dependence checking.  */

static void
mips_avoid_hazard (rtx after, rtx insn, int *hilo_delay,
                   rtx *delayed_reg, rtx lo_reg)
{
  rtx pattern, set;
  int nops, ninsns, hazard_set;

  if (!INSN_P (insn))
    return;

  pattern = PATTERN (insn);

  /* Do not put the whole function in .set noreorder if it contains
     an asm statement.  We don't know whether there will be hazards
     between the asm statement and the gcc-generated code.  */
  if (GET_CODE (pattern) == ASM_INPUT || asm_noperands (pattern) >= 0)
    cfun->machine->all_noreorder_p = false;

  /* Ignore zero-length instructions (barriers and the like).  */
  ninsns = get_attr_length (insn) / 4;
  if (ninsns == 0)
    return;

  /* Work out how many nops are needed.  Note that we only care about
     registers that are explicitly mentioned in the instruction's pattern.
     It doesn't matter that calls use the argument registers or that they
     clobber hi and lo.  */
  if (*hilo_delay < 2 && reg_set_p (lo_reg, pattern))
    nops = 2 - *hilo_delay;
  else if (*delayed_reg != 0 && reg_referenced_p (*delayed_reg, pattern))
    nops = 1;
  else
    nops = 0;

  /* Insert the nops between this instruction and the previous one.
     Each new nop takes us further from the last hilo hazard.  */
  *hilo_delay += nops;
  while (nops-- > 0)
    emit_insn_after (gen_hazard_nop (), after);

  /* Set up the state for the next instruction.  */
  *hilo_delay += ninsns;
  *delayed_reg = 0;
  if (INSN_CODE (insn) >= 0)
    switch (get_attr_hazard (insn))
      {
      case HAZARD_NONE:
        break;

      case HAZARD_HILO:
        *hilo_delay = 0;
        break;

      case HAZARD_DELAY:
        hazard_set = (int) get_attr_hazard_set (insn);
        if (hazard_set == 0)
          set = single_set (insn);
        else
          {
            gcc_assert (GET_CODE (PATTERN (insn)) == PARALLEL);
            set = XVECEXP (PATTERN (insn), 0, hazard_set - 1);
          }
        gcc_assert (set && GET_CODE (set) == SET);
        *delayed_reg = SET_DEST (set);
        break;
      }
}


/* Go through the instruction stream and insert nops where necessary.
   See if the whole function can then be put into .set noreorder &
   .set nomacro.  */

static void
mips_avoid_hazards (void)
{
  rtx insn, last_insn, lo_reg, delayed_reg;
  int hilo_delay, i;

  /* Force all instructions to be split into their final form.  */
  split_all_insns_noflow ();

  /* Recalculate instruction lengths without taking nops into account.  */
  cfun->machine->ignore_hazard_length_p = true;
  shorten_branches (get_insns ());

  cfun->machine->all_noreorder_p = true;

  /* Profiled functions can't be all noreorder because the profiler
     support uses assembler macros.  */
  if (current_function_profile)
    cfun->machine->all_noreorder_p = false;

  /* Code compiled with -mfix-vr4120 can't be all noreorder because
     we rely on the assembler to work around some errata.  */
  if (TARGET_FIX_VR4120)
    cfun->machine->all_noreorder_p = false;

  /* The same is true for -mfix-vr4130 if we might generate mflo or
     mfhi instructions.  Note that we avoid using mflo and mfhi if
     the VR4130 macc and dmacc instructions are available instead;
     see the *mfhilo_{si,di}_macc patterns.  */
  if (TARGET_FIX_VR4130 && !ISA_HAS_MACCHI)
    cfun->machine->all_noreorder_p = false;

  last_insn = 0;
  hilo_delay = 2;
  delayed_reg = 0;
  lo_reg = gen_rtx_REG (SImode, LO_REGNUM);

  for (insn = get_insns (); insn != 0; insn = NEXT_INSN (insn))
    if (INSN_P (insn))
      {
        if (GET_CODE (PATTERN (insn)) == SEQUENCE)
          for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
            mips_avoid_hazard (last_insn, XVECEXP (PATTERN (insn), 0, i),
                               &hilo_delay, &delayed_reg, lo_reg);
        else
          mips_avoid_hazard (last_insn, insn, &hilo_delay,
                             &delayed_reg, lo_reg);

        last_insn = insn;
      }
}


/* Implement TARGET_MACHINE_DEPENDENT_REORG.  */

static void
mips_reorg (void)
{
  mips16_lay_out_constants ();
  if (TARGET_EXPLICIT_RELOCS)
    {
      if (mips_flag_delayed_branch)
        dbr_schedule (get_insns ());
      mips_avoid_hazards ();
      if (TUNE_MIPS4130 && TARGET_VR4130_ALIGN)
        vr4130_align_insns ();
    }
}
\f
/* Implement TARGET_ASM_OUTPUT_MI_THUNK.  Generate rtl rather than asm text
   in order to avoid duplicating too much logic from elsewhere.  */

static void
mips_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
                      HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset,
                      tree function)
{
  rtx this, temp1, temp2, insn, fnaddr;
  bool use_sibcall_p;

  /* Pretend to be a post-reload pass while generating rtl.  */
  reload_completed = 1;

  /* Mark the end of the (empty) prologue.  */
  emit_note (NOTE_INSN_PROLOGUE_END);

  /* Determine if we can use a sibcall to call FUNCTION directly.  */
  fnaddr = XEXP (DECL_RTL (function), 0);
  use_sibcall_p = (mips_function_ok_for_sibcall (function, NULL)
                   && const_call_insn_operand (fnaddr, Pmode));

  /* Determine if we need to load FNADDR from the GOT.  */
  if (!use_sibcall_p)
    switch (mips_classify_symbol (fnaddr, SYMBOL_CONTEXT_LEA))
      {
      case SYMBOL_GOT_PAGE_OFST:
      case SYMBOL_GOT_DISP:
        /* Pick a global pointer.  Use a call-clobbered register if
           TARGET_CALL_SAVED_GP.  */
        cfun->machine->global_pointer =
          TARGET_CALL_SAVED_GP ? 15 : GLOBAL_POINTER_REGNUM;
        SET_REGNO (pic_offset_table_rtx, cfun->machine->global_pointer);

        /* Set up the global pointer for n32 or n64 abicalls.  */
        mips_emit_loadgp ();
        break;

      default:
        break;
      }

  /* We need two temporary registers in some cases.  */
  temp1 = gen_rtx_REG (Pmode, 2);
  temp2 = gen_rtx_REG (Pmode, 3);

  /* Find out which register contains the "this" pointer.  */
  if (aggregate_value_p (TREE_TYPE (TREE_TYPE (function)), function))
    this = gen_rtx_REG (Pmode, GP_ARG_FIRST + 1);
  else
    this = gen_rtx_REG (Pmode, GP_ARG_FIRST);

  /* Add DELTA to THIS.  */
  if (delta != 0)
    {
      rtx offset = GEN_INT (delta);
      if (!SMALL_OPERAND (delta))
        {
          mips_emit_move (temp1, offset);
          offset = temp1;
        }
      emit_insn (gen_add3_insn (this, this, offset));
    }

  /* If needed, add *(*THIS + VCALL_OFFSET) to THIS.  */
  if (vcall_offset != 0)
    {
      rtx addr;

      /* Set TEMP1 to *THIS.  */
      mips_emit_move (temp1, gen_rtx_MEM (Pmode, this));

      /* Set ADDR to a legitimate address for *THIS + VCALL_OFFSET.  */
      addr = mips_add_offset (temp2, temp1, vcall_offset);

      /* Load the offset and add it to THIS.  */
      mips_emit_move (temp1, gen_rtx_MEM (Pmode, addr));
      emit_insn (gen_add3_insn (this, this, temp1));
    }

  /* Jump to the target function.  Use a sibcall if direct jumps are
     allowed, otherwise load the address into a register first.  */
  if (use_sibcall_p)
    {
      insn = emit_call_insn (gen_sibcall_internal (fnaddr, const0_rtx));
      SIBLING_CALL_P (insn) = 1;
    }
  else
    {
      /* This is messy.  gas treats "la $25,foo" as part of a call
         sequence and may allow a global "foo" to be lazily bound.
         The general move patterns therefore reject this combination.

         In this context, lazy binding would actually be OK
         for TARGET_CALL_CLOBBERED_GP, but it's still wrong for
         TARGET_CALL_SAVED_GP; see mips_load_call_address.
         We must therefore load the address via a temporary
         register if mips_dangerous_for_la25_p.

         If we jump to the temporary register rather than $25, the assembler
         can use the move insn to fill the jump's delay slot.  */
      if (TARGET_USE_PIC_FN_ADDR_REG
          && !mips_dangerous_for_la25_p (fnaddr))
        temp1 = gen_rtx_REG (Pmode, PIC_FUNCTION_ADDR_REGNUM);
      mips_load_call_address (temp1, fnaddr, true);

      if (TARGET_USE_PIC_FN_ADDR_REG
          && REGNO (temp1) != PIC_FUNCTION_ADDR_REGNUM)
        mips_emit_move (gen_rtx_REG (Pmode, PIC_FUNCTION_ADDR_REGNUM), temp1);
      emit_jump_insn (gen_indirect_jump (temp1));
    }

  /* Run just enough of rest_of_compilation.  This sequence was
     "borrowed" from alpha.c.  */
  insn = get_insns ();
  insn_locators_alloc ();
  split_all_insns_noflow ();
  mips16_lay_out_constants ();
  shorten_branches (insn);
  final_start_function (insn, file, 1);
  final (insn, file, 1);
  final_end_function ();

  /* Clean up the vars set above.  Note that final_end_function resets
     the global pointer for us.  */
  reload_completed = 0;
}
\f
static GTY(()) int was_mips16_p = -1;

/* Set up the target-dependent global state so that it matches the
   current function's ISA mode.  */

static void
mips_set_mips16_mode (int mips16_p)
{
  if (mips16_p == was_mips16_p)
    return;

  /* Restore base settings of various flags.  */
  target_flags = mips_base_target_flags;
  flag_delayed_branch = mips_flag_delayed_branch;
  flag_schedule_insns = mips_base_schedule_insns;
  flag_reorder_blocks_and_partition = mips_base_reorder_blocks_and_partition;
  flag_move_loop_invariants = mips_base_move_loop_invariants;
  align_loops = mips_base_align_loops;
  align_jumps = mips_base_align_jumps;
  align_functions = mips_base_align_functions;

  if (mips16_p)
    {
      /* Select mips16 instruction set.  */
      target_flags |= MASK_MIPS16;

      /* Don't run the scheduler before reload, since it tends to
         increase register pressure.  */
      flag_schedule_insns = 0;

      /* Don't do hot/cold partitioning.  The constant layout code expects
         the whole function to be in a single section.  */
      flag_reorder_blocks_and_partition = 0;

      /* Don't move loop invariants, because it tends to increase
         register pressure.  It also introduces an extra move in cases
         where the constant is the first operand in a two-operand binary
         instruction, or when it forms a register argument to a functon
         call.  */
      flag_move_loop_invariants = 0;

      /* Silently disable -mexplicit-relocs since it doesn't apply
         to mips16 code.  Even so, it would overly pedantic to warn
         about "-mips16 -mexplicit-relocs", especially given that
         we use a %gprel() operator.  */
      target_flags &= ~MASK_EXPLICIT_RELOCS;

      /* Experiments suggest we get the best overall results from using
         the range of an unextended lw or sw.  Code that makes heavy use
         of byte or short accesses can do better with ranges of 0...31
         and 0...63 respectively, but most code is sensitive to the range
         of lw and sw instead.  */
      targetm.min_anchor_offset = 0;
      targetm.max_anchor_offset = 127;

      if (flag_pic || TARGET_ABICALLS)
        sorry ("MIPS16 PIC");
    }
  else
    {
      /* Reset to select base non-mips16 ISA.  */
      target_flags &= ~MASK_MIPS16;

      /* When using explicit relocs, we call dbr_schedule from within
         mips_reorg.  */
      if (TARGET_EXPLICIT_RELOCS)
        flag_delayed_branch = 0;

      /* Provide default values for align_* for 64-bit targets.  */
      if (TARGET_64BIT)
        {
          if (align_loops == 0)
            align_loops = 8;
          if (align_jumps == 0)
            align_jumps = 8;
          if (align_functions == 0)
            align_functions = 8;
        }

      targetm.min_anchor_offset = -32768;
      targetm.max_anchor_offset = 32767;
    }

  /* (Re)initialize mips target internals for new ISA.  */
  mips_init_split_addresses ();
  mips_init_relocs ();

  if (was_mips16_p >= 0)
    /* Reinitialize target-dependent state.  */
    target_reinit ();

  was_mips16_p = TARGET_MIPS16;
}

/* Implement TARGET_SET_CURRENT_FUNCTION.  Decide whether the current
   function should use the MIPS16 ISA and switch modes accordingly.  */

static void
mips_set_current_function (tree fndecl)
{
  mips_set_mips16_mode (mips_use_mips16_mode_p (fndecl));
}
\f
/* Allocate a chunk of memory for per-function machine-dependent data.  */
static struct machine_function *
mips_init_machine_status (void)
{
  return ((struct machine_function *)
          ggc_alloc_cleared (sizeof (struct machine_function)));
}

/* Return the processor associated with the given ISA level, or null
   if the ISA isn't valid.  */

static const struct mips_cpu_info *
mips_cpu_info_from_isa (int isa)
{
  unsigned int i;

  for (i = 0; i < ARRAY_SIZE (mips_cpu_info_table); i++)
    if (mips_cpu_info_table[i].isa == isa)
      return mips_cpu_info_table + i;

  return 0;
}

/* Return true if GIVEN is the same as CANONICAL, or if it is CANONICAL
   with a final "000" replaced by "k".  Ignore case.

   Note: this function is shared between GCC and GAS.  */

static bool
mips_strict_matching_cpu_name_p (const char *canonical, const char *given)
{
  while (*given != 0 && TOLOWER (*given) == TOLOWER (*canonical))
    given++, canonical++;

  return ((*given == 0 && *canonical == 0)
          || (strcmp (canonical, "000") == 0 && strcasecmp (given, "k") == 0));
}


/* Return true if GIVEN matches CANONICAL, where GIVEN is a user-supplied
   CPU name.  We've traditionally allowed a lot of variation here.

   Note: this function is shared between GCC and GAS.  */

static bool
mips_matching_cpu_name_p (const char *canonical, const char *given)
{
  /* First see if the name matches exactly, or with a final "000"
     turned into "k".  */
  if (mips_strict_matching_cpu_name_p (canonical, given))
    return true;

  /* If not, try comparing based on numerical designation alone.
     See if GIVEN is an unadorned number, or 'r' followed by a number.  */
  if (TOLOWER (*given) == 'r')
    given++;
  if (!ISDIGIT (*given))
    return false;

  /* Skip over some well-known prefixes in the canonical name,
     hoping to find a number there too.  */
  if (TOLOWER (canonical[0]) == 'v' && TOLOWER (canonical[1]) == 'r')
    canonical += 2;
  else if (TOLOWER (canonical[0]) == 'r' && TOLOWER (canonical[1]) == 'm')
    canonical += 2;
  else if (TOLOWER (canonical[0]) == 'r')
    canonical += 1;

  return mips_strict_matching_cpu_name_p (canonical, given);
}


/* Return the mips_cpu_info entry for the processor or ISA given
   by CPU_STRING.  Return null if the string isn't recognized.

   A similar function exists in GAS.  */

static const struct mips_cpu_info *
mips_parse_cpu (const char *cpu_string)
{
  unsigned int i;
  const char *s;

  /* In the past, we allowed upper-case CPU names, but it doesn't
     work well with the multilib machinery.  */
  for (s = cpu_string; *s != 0; s++)
    if (ISUPPER (*s))
      {
        warning (0, "the cpu name must be lower case");
        break;
      }

  /* 'from-abi' selects the most compatible architecture for the given
     ABI: MIPS I for 32-bit ABIs and MIPS III for 64-bit ABIs.  For the
     EABIs, we have to decide whether we're using the 32-bit or 64-bit
     version.  Look first at the -mgp options, if given, otherwise base
     the choice on MASK_64BIT in TARGET_DEFAULT.  */
  if (strcasecmp (cpu_string, "from-abi") == 0)
    return mips_cpu_info_from_isa (ABI_NEEDS_32BIT_REGS ? 1
                                   : ABI_NEEDS_64BIT_REGS ? 3
                                   : (TARGET_64BIT ? 3 : 1));

  /* 'default' has traditionally been a no-op.  Probably not very useful.  */
  if (strcasecmp (cpu_string, "default") == 0)
    return 0;

  for (i = 0; i < ARRAY_SIZE (mips_cpu_info_table); i++)
    if (mips_matching_cpu_name_p (mips_cpu_info_table[i].name, cpu_string))
      return mips_cpu_info_table + i;

  return 0;
}


/* Set up globals to generate code for the ISA or processor
   described by INFO.  */

static void
mips_set_architecture (const struct mips_cpu_info *info)
{
  if (info != 0)
    {
      mips_arch_info = info;
      mips_arch = info->cpu;
      mips_isa = info->isa;
    }
}


/* Likewise for tuning.  */

static void
mips_set_tune (const struct mips_cpu_info *info)
{
  if (info != 0)
    {
      mips_tune_info = info;
      mips_tune = info->cpu;
    }
}

/* Implement TARGET_HANDLE_OPTION.  */

static bool
mips_handle_option (size_t code, const char *arg, int value ATTRIBUTE_UNUSED)
{
  switch (code)
    {
    case OPT_mabi_:
      if (strcmp (arg, "32") == 0)
        mips_abi = ABI_32;
      else if (strcmp (arg, "o64") == 0)
        mips_abi = ABI_O64;
      else if (strcmp (arg, "n32") == 0)
        mips_abi = ABI_N32;
      else if (strcmp (arg, "64") == 0)
        mips_abi = ABI_64;
      else if (strcmp (arg, "eabi") == 0)
        mips_abi = ABI_EABI;
      else
        return false;
      return true;

    case OPT_march_:
    case OPT_mtune_:
      return mips_parse_cpu (arg) != 0;

    case OPT_mips:
      mips_isa_info = mips_parse_cpu (ACONCAT (("mips", arg, NULL)));
      return mips_isa_info != 0;

    case OPT_mno_flush_func:
      mips_cache_flush_func = NULL;
      return true;

    case OPT_mcode_readable_:
      if (strcmp (arg, "yes") == 0)
        mips_code_readable = CODE_READABLE_YES;
      else if (strcmp (arg, "pcrel") == 0)
        mips_code_readable = CODE_READABLE_PCREL;
      else if (strcmp (arg, "no") == 0)
        mips_code_readable = CODE_READABLE_NO;
      else
        return false;
      return true;

    default:
      return true;
    }
}

/* Set up the threshold for data to go into the small data area, instead
   of the normal data area, and detect any conflicts in the switches.  */

void
override_options (void)
{
  int i, start, regno;
  enum machine_mode mode;

#ifdef SUBTARGET_OVERRIDE_OPTIONS
  SUBTARGET_OVERRIDE_OPTIONS;
#endif

  mips_section_threshold = g_switch_set ? g_switch_value : MIPS_DEFAULT_GVALUE;

  /* The following code determines the architecture and register size.
     Similar code was added to GAS 2.14 (see tc-mips.c:md_after_parse_args()).
     The GAS and GCC code should be kept in sync as much as possible.  */

  if (mips_arch_string != 0)
    mips_set_architecture (mips_parse_cpu (mips_arch_string));

  if (mips_isa_info != 0)
    {
      if (mips_arch_info == 0)
        mips_set_architecture (mips_isa_info);
      else if (mips_arch_info->isa != mips_isa_info->isa)
        error ("-%s conflicts with the other architecture options, "
               "which specify a %s processor",
               mips_isa_info->name,
               mips_cpu_info_from_isa (mips_arch_info->isa)->name);
    }

  if (mips_arch_info == 0)
    {
#ifdef MIPS_CPU_STRING_DEFAULT
      mips_set_architecture (mips_parse_cpu (MIPS_CPU_STRING_DEFAULT));
#else
      mips_set_architecture (mips_cpu_info_from_isa (MIPS_ISA_DEFAULT));
#endif
    }

  if (ABI_NEEDS_64BIT_REGS && !ISA_HAS_64BIT_REGS)
    error ("-march=%s is not compatible with the selected ABI",
           mips_arch_info->name);

  /* Optimize for mips_arch, unless -mtune selects a different processor.  */
  if (mips_tune_string != 0)
    mips_set_tune (mips_parse_cpu (mips_tune_string));

  if (mips_tune_info == 0)
    mips_set_tune (mips_arch_info);

  /* Set cost structure for the processor.  */
  if (optimize_size)
    mips_cost = &mips_rtx_cost_optimize_size;
  else
    mips_cost = &mips_rtx_cost_data[mips_tune];

  /* If the user hasn't specified a branch cost, use the processor's
     default.  */
  if (mips_branch_cost == 0)
    mips_branch_cost = mips_cost->branch_cost;

  if ((target_flags_explicit & MASK_64BIT) != 0)
    {
      /* The user specified the size of the integer registers.  Make sure
         it agrees with the ABI and ISA.  */
      if (TARGET_64BIT && !ISA_HAS_64BIT_REGS)
        error ("-mgp64 used with a 32-bit processor");
      else if (!TARGET_64BIT && ABI_NEEDS_64BIT_REGS)
        error ("-mgp32 used with a 64-bit ABI");
      else if (TARGET_64BIT && ABI_NEEDS_32BIT_REGS)
        error ("-mgp64 used with a 32-bit ABI");
    }
  else
    {
      /* Infer the integer register size from the ABI and processor.
         Restrict ourselves to 32-bit registers if that's all the
         processor has, or if the ABI cannot handle 64-bit registers.  */
      if (ABI_NEEDS_32BIT_REGS || !ISA_HAS_64BIT_REGS)
        target_flags &= ~MASK_64BIT;
      else
        target_flags |= MASK_64BIT;
    }

  if ((target_flags_explicit & MASK_FLOAT64) != 0)
    {
      /* Really, -mfp32 and -mfp64 are ornamental options.  There's
         only one right answer here.  */
      if (TARGET_64BIT && TARGET_DOUBLE_FLOAT && !TARGET_FLOAT64)
        error ("unsupported combination: %s", "-mgp64 -mfp32 -mdouble-float");
      else if (!TARGET_64BIT && TARGET_FLOAT64
               && !(ISA_HAS_MXHC1 && mips_abi == ABI_32))
        error ("-mgp32 and -mfp64 can only be combined if the target"
               " supports the mfhc1 and mthc1 instructions");
      else if (TARGET_SINGLE_FLOAT && TARGET_FLOAT64)
        error ("unsupported combination: %s", "-mfp64 -msingle-float");
    }
  else
    {
      /* -msingle-float selects 32-bit float registers.  Otherwise the
         float registers should be the same size as the integer ones.  */
      if (TARGET_64BIT && TARGET_DOUBLE_FLOAT)
        target_flags |= MASK_FLOAT64;
      else
        target_flags &= ~MASK_FLOAT64;
    }

  /* End of code shared with GAS.  */

  if ((target_flags_explicit & MASK_LONG64) == 0)
    {
      if ((mips_abi == ABI_EABI && TARGET_64BIT) || mips_abi == ABI_64)
        target_flags |= MASK_LONG64;
      else
        target_flags &= ~MASK_LONG64;
    }

  if (!TARGET_OLDABI)
    flag_pcc_struct_return = 0;

  if ((target_flags_explicit & MASK_BRANCHLIKELY) == 0)
    {
      /* If neither -mbranch-likely nor -mno-branch-likely was given
         on the command line, set MASK_BRANCHLIKELY based on the target
         architecture and tuning flags.  Annulled delay slots are a
         size win, so we only consider the processor-specific tuning
         for !optimize_size.  */
      if (ISA_HAS_BRANCHLIKELY
          && (optimize_size
              || (mips_tune_info->tune_flags & PTF_AVOID_BRANCHLIKELY) == 0))
        target_flags |= MASK_BRANCHLIKELY;
      else
        target_flags &= ~MASK_BRANCHLIKELY;
    }
  else if (TARGET_BRANCHLIKELY && !ISA_HAS_BRANCHLIKELY)
    warning (0, "the %qs architecture does not support branch-likely"
             " instructions", mips_arch_info->name);

  /* The effect of -mabicalls isn't defined for the EABI.  */
  if (mips_abi == ABI_EABI && TARGET_ABICALLS)
    {
      error ("unsupported combination: %s", "-mabicalls -mabi=eabi");
      target_flags &= ~MASK_ABICALLS;
    }

  /* MIPS16 cannot generate PIC yet.  */
  if (TARGET_MIPS16 && (flag_pic || TARGET_ABICALLS))
    {
      sorry ("MIPS16 PIC");
      target_flags &= ~MASK_ABICALLS;
      flag_pic = flag_pie = flag_shlib = 0;
    }

  if (TARGET_ABICALLS)
    /* We need to set flag_pic for executables as well as DSOs
       because we may reference symbols that are not defined in
       the final executable.  (MIPS does not use things like
       copy relocs, for example.)

       Also, there is a body of code that uses __PIC__ to distinguish
       between -mabicalls and -mno-abicalls code.  */
    flag_pic = 1;

  /* -mvr4130-align is a "speed over size" optimization: it usually produces
     faster code, but at the expense of more nops.  Enable it at -O3 and
     above.  */
  if (optimize > 2 && (target_flags_explicit & MASK_VR4130_ALIGN) == 0)
    target_flags |= MASK_VR4130_ALIGN;

  /* Prefer a call to memcpy over inline code when optimizing for size,
     though see MOVE_RATIO in mips.h.  */
  if (optimize_size && (target_flags_explicit & MASK_MEMCPY) == 0)
    target_flags |= MASK_MEMCPY;

  /* If we have a nonzero small-data limit, check that the -mgpopt
     setting is consistent with the other target flags.  */
  if (mips_section_threshold > 0)
    {
      if (!TARGET_GPOPT)
        {
          if (!TARGET_MIPS16 && !TARGET_EXPLICIT_RELOCS)
            error ("%<-mno-gpopt%> needs %<-mexplicit-relocs%>");

          TARGET_LOCAL_SDATA = false;
          TARGET_EXTERN_SDATA = false;
        }
      else
        {
          if (TARGET_VXWORKS_RTP)
            warning (0, "cannot use small-data accesses for %qs", "-mrtp");

          if (TARGET_ABICALLS)
            warning (0, "cannot use small-data accesses for %qs",
                     "-mabicalls");
        }
    }

#ifdef MIPS_TFMODE_FORMAT
  REAL_MODE_FORMAT (TFmode) = &MIPS_TFMODE_FORMAT;
#endif

  /* Make sure that the user didn't turn off paired single support when
     MIPS-3D support is requested.  */
  if (TARGET_MIPS3D && (target_flags_explicit & MASK_PAIRED_SINGLE_FLOAT)
      && !TARGET_PAIRED_SINGLE_FLOAT)
    error ("-mips3d requires -mpaired-single");

  /* If TARGET_MIPS3D, enable MASK_PAIRED_SINGLE_FLOAT.  */
  if (TARGET_MIPS3D)
    target_flags |= MASK_PAIRED_SINGLE_FLOAT;

  /* Make sure that when TARGET_PAIRED_SINGLE_FLOAT is true, TARGET_FLOAT64
     and TARGET_HARD_FLOAT_ABI are both true.  */
  if (TARGET_PAIRED_SINGLE_FLOAT && !(TARGET_FLOAT64 && TARGET_HARD_FLOAT_ABI))
    error ("-mips3d/-mpaired-single must be used with -mfp64 -mhard-float");

  /* Make sure that the ISA supports TARGET_PAIRED_SINGLE_FLOAT when it is
     enabled.  */
  if (TARGET_PAIRED_SINGLE_FLOAT && !ISA_MIPS64)
    error ("-mips3d/-mpaired-single must be used with -mips64");

  /* If TARGET_DSPR2, enable MASK_DSP.  */
  if (TARGET_DSPR2)
    target_flags |= MASK_DSP;

  mips_init_print_operand_punct ();

  /* Set up array to map GCC register number to debug register number.
     Ignore the special purpose register numbers.  */

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    {
      mips_dbx_regno[i] = INVALID_REGNUM;
      if (GP_REG_P (i) || FP_REG_P (i) || ALL_COP_REG_P (i))
        mips_dwarf_regno[i] = i;
      else
        mips_dwarf_regno[i] = INVALID_REGNUM;
    }

  start = GP_DBX_FIRST - GP_REG_FIRST;
  for (i = GP_REG_FIRST; i <= GP_REG_LAST; i++)
    mips_dbx_regno[i] = i + start;

  start = FP_DBX_FIRST - FP_REG_FIRST;
  for (i = FP_REG_FIRST; i <= FP_REG_LAST; i++)
    mips_dbx_regno[i] = i + start;

  /* HI and LO debug registers use big-endian ordering.  */
  mips_dbx_regno[HI_REGNUM] = MD_DBX_FIRST + 0;
  mips_dbx_regno[LO_REGNUM] = MD_DBX_FIRST + 1;
  mips_dwarf_regno[HI_REGNUM] = MD_REG_FIRST + 0;
  mips_dwarf_regno[LO_REGNUM] = MD_REG_FIRST + 1;
  for (i = DSP_ACC_REG_FIRST; i <= DSP_ACC_REG_LAST; i += 2)
    {
      mips_dwarf_regno[i + TARGET_LITTLE_ENDIAN] = i;
      mips_dwarf_regno[i + TARGET_BIG_ENDIAN] = i + 1;
    }

  /* Set up array giving whether a given register can hold a given mode.  */

  for (mode = VOIDmode;
       mode != MAX_MACHINE_MODE;
       mode = (enum machine_mode) ((int)mode + 1))
    {
      register int size              = GET_MODE_SIZE (mode);
      register enum mode_class class = GET_MODE_CLASS (mode);

      for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
        {
          register int temp;

          if (mode == CCV2mode)
            temp = (ISA_HAS_8CC
                    && ST_REG_P (regno)
                    && (regno - ST_REG_FIRST) % 2 == 0);

          else if (mode == CCV4mode)
            temp = (ISA_HAS_8CC
                    && ST_REG_P (regno)
                    && (regno - ST_REG_FIRST) % 4 == 0);

          else if (mode == CCmode)
            {
              if (! ISA_HAS_8CC)
                temp = (regno == FPSW_REGNUM);
              else
                temp = (ST_REG_P (regno) || GP_REG_P (regno)
                        || FP_REG_P (regno));
            }

          else if (GP_REG_P (regno))
            temp = ((regno & 1) == 0 || size <= UNITS_PER_WORD);

          else if (FP_REG_P (regno))
            temp = ((((regno % MAX_FPRS_PER_FMT) == 0)
                     || (MIN_FPRS_PER_FMT == 1
                         && size <= UNITS_PER_FPREG))
                    && (((class == MODE_FLOAT || class == MODE_COMPLEX_FLOAT
                          || class == MODE_VECTOR_FLOAT)
                         && size <= UNITS_PER_FPVALUE)
                        /* Allow integer modes that fit into a single
                           register.  We need to put integers into FPRs
                           when using instructions like cvt and trunc.
                           We can't allow sizes smaller than a word,
                           the FPU has no appropriate load/store
                           instructions for those.  */
                        || (class == MODE_INT
                            && size >= MIN_UNITS_PER_WORD
                            && size <= UNITS_PER_FPREG)
                        /* Allow TFmode for CCmode reloads.  */
                        || (ISA_HAS_8CC && mode == TFmode)));

          else if (ACC_REG_P (regno))
            temp = ((INTEGRAL_MODE_P (mode) || ALL_FIXED_POINT_MODE_P (mode))
                    && size <= UNITS_PER_WORD * 2
                    && (size <= UNITS_PER_WORD
                        || regno == MD_REG_FIRST
                        || (DSP_ACC_REG_P (regno)
                            && ((regno - DSP_ACC_REG_FIRST) & 1) == 0)));

          else if (ALL_COP_REG_P (regno))
            temp = (class == MODE_INT && size <= UNITS_PER_WORD);
          else
            temp = 0;

          mips_hard_regno_mode_ok[(int)mode][regno] = temp;
        }
    }

  /* Save GPR registers in word_mode sized hunks.  word_mode hasn't been
     initialized yet, so we can't use that here.  */
  gpr_mode = TARGET_64BIT ? DImode : SImode;

  /* Function to allocate machine-dependent function status.  */
  init_machine_status = &mips_init_machine_status;

  /* Default to working around R4000 errata only if the processor
     was selected explicitly.  */
  if ((target_flags_explicit & MASK_FIX_R4000) == 0
      && mips_matching_cpu_name_p (mips_arch_info->name, "r4000"))
    target_flags |= MASK_FIX_R4000;

  /* Default to working around R4400 errata only if the processor
     was selected explicitly.  */
  if ((target_flags_explicit & MASK_FIX_R4400) == 0
      && mips_matching_cpu_name_p (mips_arch_info->name, "r4400"))
    target_flags |= MASK_FIX_R4400;

  /* Save base state of options.  */
  mips_base_mips16 = TARGET_MIPS16;
  mips_base_target_flags = target_flags;
  mips_flag_delayed_branch = flag_delayed_branch;
  mips_base_schedule_insns = flag_schedule_insns;
  mips_base_reorder_blocks_and_partition = flag_reorder_blocks_and_partition;
  mips_base_move_loop_invariants = flag_move_loop_invariants;
  mips_base_align_loops = align_loops;
  mips_base_align_jumps = align_jumps;
  mips_base_align_functions = align_functions;

  /* Now select the mips16 or 32-bit instruction set, as requested.  */
  mips_set_mips16_mode (mips_base_mips16);
}

/* Swap the register information for registers I and I + 1, which
   currently have the wrong endianness.  Note that the registers'
   fixedness and call-clobberedness might have been set on the
   command line.  */

static void
mips_swap_registers (unsigned int i)
{
  int tmpi;
  const char *tmps;

#define SWAP_INT(X, Y) (tmpi = (X), (X) = (Y), (Y) = tmpi)
#define SWAP_STRING(X, Y) (tmps = (X), (X) = (Y), (Y) = tmps)

  SWAP_INT (fixed_regs[i], fixed_regs[i + 1]);
  SWAP_INT (call_used_regs[i], call_used_regs[i + 1]);
  SWAP_INT (call_really_used_regs[i], call_really_used_regs[i + 1]);
  SWAP_STRING (reg_names[i], reg_names[i + 1]);

#undef SWAP_STRING
#undef SWAP_INT
}

/* Implement CONDITIONAL_REGISTER_USAGE.  */

void
mips_conditional_register_usage (void)
{
  if (!ISA_HAS_DSP)
    {
      int regno;

      for (regno = DSP_ACC_REG_FIRST; regno <= DSP_ACC_REG_LAST; regno++)
        fixed_regs[regno] = call_used_regs[regno] = 1;
    }
  if (!TARGET_HARD_FLOAT)
    {
      int regno;

      for (regno = FP_REG_FIRST; regno <= FP_REG_LAST; regno++)
        fixed_regs[regno] = call_used_regs[regno] = 1;
      for (regno = ST_REG_FIRST; regno <= ST_REG_LAST; regno++)
        fixed_regs[regno] = call_used_regs[regno] = 1;
    }
  else if (! ISA_HAS_8CC)
    {
      int regno;

      /* We only have a single condition code register.  We
         implement this by hiding all the condition code registers,
         and generating RTL that refers directly to ST_REG_FIRST.  */
      for (regno = ST_REG_FIRST; regno <= ST_REG_LAST; regno++)
        fixed_regs[regno] = call_used_regs[regno] = 1;
    }
  /* In mips16 mode, we permit the $t temporary registers to be used
     for reload.  We prohibit the unused $s registers, since they
     are caller saved, and saving them via a mips16 register would
     probably waste more time than just reloading the value.  */
  if (TARGET_MIPS16)
    {
      fixed_regs[18] = call_used_regs[18] = 1;
      fixed_regs[19] = call_used_regs[19] = 1;
      fixed_regs[20] = call_used_regs[20] = 1;
      fixed_regs[21] = call_used_regs[21] = 1;
      fixed_regs[22] = call_used_regs[22] = 1;
      fixed_regs[23] = call_used_regs[23] = 1;
      fixed_regs[26] = call_used_regs[26] = 1;
      fixed_regs[27] = call_used_regs[27] = 1;
      fixed_regs[30] = call_used_regs[30] = 1;
    }
  /* fp20-23 are now caller saved.  */
  if (mips_abi == ABI_64)
    {
      int regno;
      for (regno = FP_REG_FIRST + 20; regno < FP_REG_FIRST + 24; regno++)
        call_really_used_regs[regno] = call_used_regs[regno] = 1;
    }
  /* Odd registers from fp21 to fp31 are now caller saved.  */
  if (mips_abi == ABI_N32)
    {
      int regno;
      for (regno = FP_REG_FIRST + 21; regno <= FP_REG_FIRST + 31; regno+=2)
        call_really_used_regs[regno] = call_used_regs[regno] = 1;
    }
  /* Make sure that double-register accumulator values are correctly
     ordered for the current endianness.  */
  if (TARGET_LITTLE_ENDIAN)
    {
      int regno;
      mips_swap_registers (MD_REG_FIRST);
      for (regno = DSP_ACC_REG_FIRST; regno <= DSP_ACC_REG_LAST; regno += 2)
        mips_swap_registers (regno);
    }
}

/* On the mips16, we want to allocate $24 (T_REG) before other
   registers for instructions for which it is possible.  This helps
   avoid shuffling registers around in order to set up for an xor,
   encouraging the compiler to use a cmp instead.  */

void
mips_order_regs_for_local_alloc (void)
{
  register int i;

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    reg_alloc_order[i] = i;

  if (TARGET_MIPS16)
    {
      /* It really doesn't matter where we put register 0, since it is
         a fixed register anyhow.  */
      reg_alloc_order[0] = 24;
      reg_alloc_order[24] = 0;
    }
}
\f
/* Initialize the GCC target structure.  */
#undef TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP "\t.half\t"
#undef TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP "\t.word\t"
#undef TARGET_ASM_ALIGNED_DI_OP
#define TARGET_ASM_ALIGNED_DI_OP "\t.dword\t"

#undef TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE mips_output_function_prologue
#undef TARGET_ASM_FUNCTION_EPILOGUE
#define TARGET_ASM_FUNCTION_EPILOGUE mips_output_function_epilogue
#undef TARGET_ASM_SELECT_RTX_SECTION
#define TARGET_ASM_SELECT_RTX_SECTION mips_select_rtx_section
#undef TARGET_ASM_FUNCTION_RODATA_SECTION
#define TARGET_ASM_FUNCTION_RODATA_SECTION mips_function_rodata_section

#undef TARGET_SCHED_INIT
#define TARGET_SCHED_INIT mips_sched_init
#undef TARGET_SCHED_REORDER
#define TARGET_SCHED_REORDER mips_sched_reorder
#undef TARGET_SCHED_REORDER2
#define TARGET_SCHED_REORDER2 mips_sched_reorder
#undef TARGET_SCHED_VARIABLE_ISSUE
#define TARGET_SCHED_VARIABLE_ISSUE mips_variable_issue
#undef TARGET_SCHED_ADJUST_COST
#define TARGET_SCHED_ADJUST_COST mips_adjust_cost
#undef TARGET_SCHED_ISSUE_RATE
#define TARGET_SCHED_ISSUE_RATE mips_issue_rate
#undef TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD
#define TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD \
  mips_multipass_dfa_lookahead

#undef TARGET_DEFAULT_TARGET_FLAGS
#define TARGET_DEFAULT_TARGET_FLAGS             \
  (TARGET_DEFAULT                               \
   | TARGET_CPU_DEFAULT                         \
   | TARGET_ENDIAN_DEFAULT                      \
   | TARGET_FP_EXCEPTIONS_DEFAULT               \
   | MASK_CHECK_ZERO_DIV                        \
   | MASK_FUSED_MADD)
#undef TARGET_HANDLE_OPTION
#define TARGET_HANDLE_OPTION mips_handle_option

#undef TARGET_FUNCTION_OK_FOR_SIBCALL
#define TARGET_FUNCTION_OK_FOR_SIBCALL mips_function_ok_for_sibcall

#undef TARGET_INSERT_ATTRIBUTES
#define TARGET_INSERT_ATTRIBUTES mips_insert_attributes
#undef TARGET_MERGE_DECL_ATTRIBUTES
#define TARGET_MERGE_DECL_ATTRIBUTES mips_merge_decl_attributes
#undef TARGET_SET_CURRENT_FUNCTION
#define TARGET_SET_CURRENT_FUNCTION mips_set_current_function

#undef TARGET_VALID_POINTER_MODE
#define TARGET_VALID_POINTER_MODE mips_valid_pointer_mode
#undef TARGET_RTX_COSTS
#define TARGET_RTX_COSTS mips_rtx_costs
#undef TARGET_ADDRESS_COST
#define TARGET_ADDRESS_COST mips_address_cost

#undef TARGET_IN_SMALL_DATA_P
#define TARGET_IN_SMALL_DATA_P mips_in_small_data_p

#undef TARGET_MACHINE_DEPENDENT_REORG
#define TARGET_MACHINE_DEPENDENT_REORG mips_reorg

#undef TARGET_ASM_FILE_START
#define TARGET_ASM_FILE_START mips_file_start
#undef TARGET_ASM_FILE_START_FILE_DIRECTIVE
#define TARGET_ASM_FILE_START_FILE_DIRECTIVE true

#undef TARGET_INIT_LIBFUNCS
#define TARGET_INIT_LIBFUNCS mips_init_libfuncs

#undef TARGET_BUILD_BUILTIN_VA_LIST
#define TARGET_BUILD_BUILTIN_VA_LIST mips_build_builtin_va_list
#undef TARGET_GIMPLIFY_VA_ARG_EXPR
#define TARGET_GIMPLIFY_VA_ARG_EXPR mips_gimplify_va_arg_expr

#undef TARGET_PROMOTE_FUNCTION_ARGS
#define TARGET_PROMOTE_FUNCTION_ARGS hook_bool_const_tree_true
#undef TARGET_PROMOTE_FUNCTION_RETURN
#define TARGET_PROMOTE_FUNCTION_RETURN hook_bool_const_tree_true
#undef TARGET_PROMOTE_PROTOTYPES
#define TARGET_PROMOTE_PROTOTYPES hook_bool_const_tree_true

#undef TARGET_RETURN_IN_MEMORY
#define TARGET_RETURN_IN_MEMORY mips_return_in_memory
#undef TARGET_RETURN_IN_MSB
#define TARGET_RETURN_IN_MSB mips_return_in_msb

#undef TARGET_ASM_OUTPUT_MI_THUNK
#define TARGET_ASM_OUTPUT_MI_THUNK mips_output_mi_thunk
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK hook_bool_const_tree_hwi_hwi_const_tree_true

#undef TARGET_SETUP_INCOMING_VARARGS
#define TARGET_SETUP_INCOMING_VARARGS mips_setup_incoming_varargs
#undef TARGET_STRICT_ARGUMENT_NAMING
#define TARGET_STRICT_ARGUMENT_NAMING mips_strict_argument_naming
#undef TARGET_MUST_PASS_IN_STACK
#define TARGET_MUST_PASS_IN_STACK must_pass_in_stack_var_size
#undef TARGET_PASS_BY_REFERENCE
#define TARGET_PASS_BY_REFERENCE mips_pass_by_reference
#undef TARGET_CALLEE_COPIES
#define TARGET_CALLEE_COPIES mips_callee_copies
#undef TARGET_ARG_PARTIAL_BYTES
#define TARGET_ARG_PARTIAL_BYTES mips_arg_partial_bytes

#undef TARGET_MODE_REP_EXTENDED
#define TARGET_MODE_REP_EXTENDED mips_mode_rep_extended

#undef TARGET_VECTOR_MODE_SUPPORTED_P
#define TARGET_VECTOR_MODE_SUPPORTED_P mips_vector_mode_supported_p

#undef TARGET_SCALAR_MODE_SUPPORTED_P
#define TARGET_SCALAR_MODE_SUPPORTED_P mips_scalar_mode_supported_p

#undef TARGET_INIT_BUILTINS
#define TARGET_INIT_BUILTINS mips_init_builtins
#undef TARGET_EXPAND_BUILTIN
#define TARGET_EXPAND_BUILTIN mips_expand_builtin

#undef TARGET_HAVE_TLS
#define TARGET_HAVE_TLS HAVE_AS_TLS

#undef TARGET_CANNOT_FORCE_CONST_MEM
#define TARGET_CANNOT_FORCE_CONST_MEM mips_cannot_force_const_mem

#undef TARGET_ENCODE_SECTION_INFO
#define TARGET_ENCODE_SECTION_INFO mips_encode_section_info

#undef TARGET_ATTRIBUTE_TABLE
#define TARGET_ATTRIBUTE_TABLE mips_attribute_table
/* All our function attributes are related to how out-of-line copies should
   be compiled or called.  They don't in themselves prevent inlining.  */
#undef TARGET_FUNCTION_ATTRIBUTE_INLINABLE_P
#define TARGET_FUNCTION_ATTRIBUTE_INLINABLE_P hook_bool_const_tree_true

#undef TARGET_EXTRA_LIVE_ON_ENTRY
#define TARGET_EXTRA_LIVE_ON_ENTRY mips_extra_live_on_entry

#undef TARGET_USE_BLOCKS_FOR_CONSTANT_P
#define TARGET_USE_BLOCKS_FOR_CONSTANT_P mips_use_blocks_for_constant_p
#undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
#define TARGET_USE_ANCHORS_FOR_SYMBOL_P mips_use_anchors_for_symbol_p

#undef  TARGET_COMP_TYPE_ATTRIBUTES
#define TARGET_COMP_TYPE_ATTRIBUTES mips_comp_type_attributes

#ifdef HAVE_AS_DTPRELWORD
#undef TARGET_ASM_OUTPUT_DWARF_DTPREL
#define TARGET_ASM_OUTPUT_DWARF_DTPREL mips_output_dwarf_dtprel
#endif
#undef TARGET_DWARF_REGISTER_SPAN
#define TARGET_DWARF_REGISTER_SPAN mips_dwarf_register_span

struct gcc_target targetm = TARGET_INITIALIZER;
\f
#include "gt-mips.h"