/* Register to Stack convert for GNU compiler.
- Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
- This file is part of GNU CC.
+ This file is part of GCC.
- GNU CC is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
+ 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 2, or (at your option)
any later version.
- GNU CC 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.
+ 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 GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with GCC; see the file COPYING. If not, write to the Free
+ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+ 02111-1307, USA. */
/* This pass converts stack-like registers from the "flat register
file" model that gcc uses, to a stack convention that the 387 uses.
\f
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "flags.h"
-#include "insn-flags.h"
#include "toplev.h"
#include "recog.h"
#include "output.h"
#include "basic-block.h"
#include "varray.h"
+#include "reload.h"
+#include "ggc.h"
+
+/* We use this array to cache info about insns, because otherwise we
+ spend too much time in stack_regs_mentioned_p.
+
+ Indexed by insn UIDs. A value of zero is uninitialized, one indicates
+ the insn uses stack registers, two indicates the insn does not use
+ stack registers. */
+static GTY(()) varray_type stack_regs_mentioned_data;
#ifdef STACK_REGS
{
int top; /* index to top stack element */
HARD_REG_SET reg_set; /* set of live registers */
- char reg[REG_STACK_SIZE]; /* register - stack mapping */
+ unsigned char reg[REG_STACK_SIZE];/* register - stack mapping */
} *stack;
-/* This is used to carry information about basic blocks. It is
+/* This is used to carry information about basic blocks. It is
attached to the AUX field of the standard CFG block. */
typedef struct block_info_def
{
struct stack_def stack_in; /* Input stack configuration. */
+ struct stack_def stack_out; /* Output stack configuration. */
HARD_REG_SET out_reg_set; /* Stack regs live on output. */
int done; /* True if block already converted. */
+ int predecessors; /* Number of predecessors that needs
+ to be visited. */
} *block_info;
#define BLOCK_INFO(B) ((block_info) (B)->aux)
EMIT_BEFORE
};
-/* We use this array to cache info about insns, because otherwise we
- spend too much time in stack_regs_mentioned_p.
-
- Indexed by insn UIDs. A value of zero is uninitialized, one indicates
- the insn uses stack registers, two indicates the insn does not use
- stack registers. */
-static varray_type stack_regs_mentioned_data;
-
/* The block we're currently working on. */
static basic_block current_block;
-/* This is the register file for all register after conversion */
+/* This is the register file for all register after conversion. */
static rtx
FP_mode_reg[LAST_STACK_REG+1-FIRST_STACK_REG][(int) MAX_MACHINE_MODE];
#define FP_MODE_REG(regno,mode) \
- (FP_mode_reg[(regno)-FIRST_STACK_REG][(int)(mode)])
+ (FP_mode_reg[(regno)-FIRST_STACK_REG][(int) (mode)])
/* Used to initialize uninitialized registers. */
static rtx nan;
/* Forward declarations */
-static int stack_regs_mentioned_p PARAMS ((rtx pat));
-static void straighten_stack PARAMS ((rtx, stack));
-static void pop_stack PARAMS ((stack, int));
-static rtx *get_true_reg PARAMS ((rtx *));
-
-static int check_asm_stack_operands PARAMS ((rtx));
-static int get_asm_operand_n_inputs PARAMS ((rtx));
-static rtx stack_result PARAMS ((tree));
-static void replace_reg PARAMS ((rtx *, int));
-static void remove_regno_note PARAMS ((rtx, enum reg_note, int));
-static int get_hard_regnum PARAMS ((stack, rtx));
-static void delete_insn_for_stacker PARAMS ((rtx));
-static rtx emit_pop_insn PARAMS ((rtx, stack, rtx,
- enum emit_where));
-static void emit_swap_insn PARAMS ((rtx, stack, rtx));
-static void move_for_stack_reg PARAMS ((rtx, stack, rtx));
-static int swap_rtx_condition_1 PARAMS ((rtx));
-static int swap_rtx_condition PARAMS ((rtx));
-static void compare_for_stack_reg PARAMS ((rtx, stack, rtx));
-static void subst_stack_regs_pat PARAMS ((rtx, stack, rtx));
-static void subst_asm_stack_regs PARAMS ((rtx, stack));
-static void subst_stack_regs PARAMS ((rtx, stack));
-static void change_stack PARAMS ((rtx, stack, stack,
- enum emit_where));
-static int convert_regs_entry PARAMS ((void));
-static void convert_regs_exit PARAMS ((void));
-static int convert_regs_1 PARAMS ((FILE *, basic_block));
-static int convert_regs_2 PARAMS ((FILE *, basic_block));
-static int convert_regs PARAMS ((FILE *));
-static void print_stack PARAMS ((FILE *, stack));
-static rtx next_flags_user PARAMS ((rtx));
-static void record_label_references PARAMS ((rtx, rtx));
+static int stack_regs_mentioned_p (rtx pat);
+static void straighten_stack (rtx, stack);
+static void pop_stack (stack, int);
+static rtx *get_true_reg (rtx *);
+
+static int check_asm_stack_operands (rtx);
+static int get_asm_operand_n_inputs (rtx);
+static rtx stack_result (tree);
+static void replace_reg (rtx *, int);
+static void remove_regno_note (rtx, enum reg_note, unsigned int);
+static int get_hard_regnum (stack, rtx);
+static rtx emit_pop_insn (rtx, stack, rtx, enum emit_where);
+static void emit_swap_insn (rtx, stack, rtx);
+static bool move_for_stack_reg (rtx, stack, rtx);
+static int swap_rtx_condition_1 (rtx);
+static int swap_rtx_condition (rtx);
+static void compare_for_stack_reg (rtx, stack, rtx);
+static bool subst_stack_regs_pat (rtx, stack, rtx);
+static void subst_asm_stack_regs (rtx, stack);
+static bool subst_stack_regs (rtx, stack);
+static void change_stack (rtx, stack, stack, enum emit_where);
+static int convert_regs_entry (void);
+static void convert_regs_exit (void);
+static int convert_regs_1 (FILE *, basic_block);
+static int convert_regs_2 (FILE *, basic_block);
+static int convert_regs (FILE *);
+static void print_stack (FILE *, stack);
+static rtx next_flags_user (rtx);
+static void record_label_references (rtx, rtx);
+static bool compensate_edge (edge, FILE *);
\f
-/* Return non-zero if any stack register is mentioned somewhere within PAT. */
+/* Return nonzero if any stack register is mentioned somewhere within PAT. */
static int
-stack_regs_mentioned_p (pat)
- rtx pat;
+stack_regs_mentioned_p (rtx pat)
{
- register const char *fmt;
- register int i;
+ const char *fmt;
+ int i;
if (STACK_REG_P (pat))
return 1;
{
if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
if (stack_regs_mentioned_p (XVECEXP (pat, i, j)))
/* Return nonzero if INSN mentions stacked registers, else return zero. */
int
-stack_regs_mentioned (insn)
- rtx insn;
+stack_regs_mentioned (rtx insn)
{
unsigned int uid, max;
int test;
- if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ if (! INSN_P (insn) || !stack_regs_mentioned_data)
return 0;
uid = INSN_UID (insn);
static rtx ix86_flags_rtx;
static rtx
-next_flags_user (insn)
- rtx insn;
+next_flags_user (rtx insn)
{
- /* Search forward looking for the first use of this value.
+ /* Search forward looking for the first use of this value.
Stop at block boundaries. */
- /* ??? This really cries for BLOCK_END! */
- while (1)
+ while (insn != BB_END (current_block))
{
insn = NEXT_INSN (insn);
- if (!insn)
- return NULL_RTX;
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
- && reg_mentioned_p (ix86_flags_rtx, PATTERN (insn)))
- return insn;
+ if (INSN_P (insn) && reg_mentioned_p (ix86_flags_rtx, PATTERN (insn)))
+ return insn;
- if (GET_CODE (insn) == JUMP_INSN
- || GET_CODE (insn) == CODE_LABEL
- || GET_CODE (insn) == CALL_INSN)
+ if (GET_CODE (insn) == CALL_INSN)
return NULL_RTX;
}
+ return NULL_RTX;
}
\f
-/* Reorganise the stack into ascending numbers,
+/* Reorganize the stack into ascending numbers,
after this insn. */
static void
-straighten_stack (insn, regstack)
- rtx insn;
- stack regstack;
+straighten_stack (rtx insn, stack regstack)
{
struct stack_def temp_stack;
int top;
for (top = temp_stack.top = regstack->top; top >= 0; top--)
temp_stack.reg[top] = FIRST_STACK_REG + temp_stack.top - top;
-
+
change_stack (insn, regstack, &temp_stack, EMIT_AFTER);
}
-/* Pop a register from the stack */
+/* Pop a register from the stack. */
static void
-pop_stack (regstack, regno)
- stack regstack;
- int regno;
+pop_stack (stack regstack, int regno)
{
int top = regstack->top;
CLEAR_HARD_REG_BIT (regstack->reg_set, regno);
regstack->top--;
- /* If regno was not at the top of stack then adjust stack */
+ /* If regno was not at the top of stack then adjust stack. */
if (regstack->reg [top] != regno)
{
int i;
dump file, if used.
Construct a CFG and run life analysis. Then convert each insn one
- by one. Run a last jump_optimize pass, if optimizing, to eliminate
+ by one. Run a last cleanup_cfg pass, if optimizing, to eliminate
code duplication created when the converter inserts pop insns on
the edges. */
-void
-reg_to_stack (first, file)
- rtx first;
- FILE *file;
+bool
+reg_to_stack (rtx first, FILE *file)
{
+ basic_block bb;
int i;
int max_uid;
- block_info bi;
+
+ /* Clean up previous run. */
+ stack_regs_mentioned_data = 0;
/* See if there is something to do. Flow analysis is quite
expensive so we might save some compilation time. */
if (regs_ever_live[i])
break;
if (i > LAST_STACK_REG)
- return;
-
- /* Ok, floating point instructions exist. If not optimizing,
- build the CFG and run life analysis. */
- find_basic_blocks (first, max_reg_num (), file);
- count_or_remove_death_notes (NULL, 1);
- life_analysis (first, max_reg_num (), file, 0);
+ return false;
+
+ /* Ok, floating point instructions exist. If not optimizing,
+ build the CFG and run life analysis.
+ Also need to rebuild life when superblock scheduling is done
+ as it don't update liveness yet. */
+ if (!optimize
+ || (flag_sched2_use_superblocks
+ && flag_schedule_insns_after_reload))
+ {
+ count_or_remove_death_notes (NULL, 1);
+ life_analysis (first, file, PROP_DEATH_NOTES);
+ }
+ mark_dfs_back_edges ();
/* Set up block info for each basic block. */
- bi = (block_info) xcalloc ((n_basic_blocks + 1), sizeof (*bi));
- for (i = n_basic_blocks - 1; i >= 0; --i)
- BASIC_BLOCK (i)->aux = bi + i;
- EXIT_BLOCK_PTR->aux = bi + n_basic_blocks;
+ alloc_aux_for_blocks (sizeof (struct block_info_def));
+ FOR_EACH_BB_REVERSE (bb)
+ {
+ edge e;
+ for (e = bb->pred; e; e = e->pred_next)
+ if (!(e->flags & EDGE_DFS_BACK)
+ && e->src != ENTRY_BLOCK_PTR)
+ BLOCK_INFO (bb)->predecessors++;
+ }
/* Create the replacement registers up front. */
for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
ix86_flags_rtx = gen_rtx_REG (CCmode, FLAGS_REG);
- /* A QNaN for initializing uninitialized variables.
+ /* A QNaN for initializing uninitialized variables.
??? We can't load from constant memory in PIC mode, because
- we're insertting these instructions before the prologue and
+ we're inserting these instructions before the prologue and
the PIC register hasn't been set up. In that case, fall back
on zero, which we can get from `ldz'. */
VARRAY_CHAR_INIT (stack_regs_mentioned_data, max_uid + 1,
"stack_regs_mentioned cache");
- if (convert_regs (file) && optimize)
- {
- jump_optimize (first, JUMP_CROSS_JUMP_DEATH_MATTERS,
- !JUMP_NOOP_MOVES, !JUMP_AFTER_REGSCAN);
- }
+ convert_regs (file);
- /* Clean up. */
- VARRAY_FREE (stack_regs_mentioned_data);
- free (bi);
+ free_aux_for_blocks ();
+ return true;
}
\f
/* Check PAT, which is in INSN, for LABEL_REFs. Add INSN to the
reference. */
static void
-record_label_references (insn, pat)
- rtx insn, pat;
+record_label_references (rtx insn, rtx pat)
{
- register enum rtx_code code = GET_CODE (pat);
- register int i;
- register const char *fmt;
+ enum rtx_code code = GET_CODE (pat);
+ int i;
+ const char *fmt;
if (code == LABEL_REF)
{
- register rtx label = XEXP (pat, 0);
- register rtx ref;
+ rtx label = XEXP (pat, 0);
+ rtx ref;
if (GET_CODE (label) != CODE_LABEL)
abort ();
record_label_references (insn, XEXP (pat, i));
if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = 0; j < XVECLEN (pat, i); j++)
record_label_references (insn, XVECEXP (pat, i, j));
}
PAT that stopped the search. */
static rtx *
-get_true_reg (pat)
- rtx *pat;
+get_true_reg (rtx *pat)
{
for (;;)
switch (GET_CODE (*pat))
{
case SUBREG:
- /* Eliminate FP subregister accesses in favour of the
+ /* Eliminate FP subregister accesses in favor of the
actual FP register in use. */
{
rtx subreg;
if (FP_REG_P (subreg = SUBREG_REG (*pat)))
{
- *pat = FP_MODE_REG (REGNO (subreg) + SUBREG_WORD (*pat),
+ int regno_off = subreg_regno_offset (REGNO (subreg),
+ GET_MODE (subreg),
+ SUBREG_BYTE (*pat),
+ GET_MODE (*pat));
+ *pat = FP_MODE_REG (REGNO (subreg) + regno_off,
GET_MODE (subreg));
default:
return pat;
}
}
\f
+/* Set if we find any malformed asms in a block. */
+static bool any_malformed_asm;
+
/* There are many rules that an asm statement for stack-like regs must
follow. Those rules are explained at the top of this file: the rule
numbers below refer to that explanation. */
static int
-check_asm_stack_operands (insn)
- rtx insn;
+check_asm_stack_operands (rtx insn)
{
int i;
int n_clobbers;
if (GET_CODE (body) == PARALLEL)
{
- clobber_reg = (rtx *) alloca (XVECLEN (body, 0) * sizeof (rtx));
+ clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx));
for (i = 0; i < XVECLEN (body, 0); i++)
if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
{
if (reg_class_size[(int) recog_op_alt[i][alt].class] != 1)
{
- error_for_asm (insn, "Output constraint %d must specify a single register", i);
+ error_for_asm (insn, "output constraint %d must specify a single register", i);
malformed_asm = 1;
}
- else
- reg_used_as_output[REGNO (recog_data.operand[i])] = 1;
+ else
+ {
+ int j;
+
+ for (j = 0; j < n_clobbers; j++)
+ if (REGNO (recog_data.operand[i]) == REGNO (clobber_reg[j]))
+ {
+ error_for_asm (insn, "output constraint %d cannot be specified together with \"%s\" clobber",
+ i, reg_names [REGNO (clobber_reg[j])]);
+ malformed_asm = 1;
+ break;
+ }
+ if (j == n_clobbers)
+ reg_used_as_output[REGNO (recog_data.operand[i])] = 1;
+ }
}
if (i != LAST_STACK_REG + 1)
{
- error_for_asm (insn, "Output regs must be grouped at top of stack");
+ error_for_asm (insn, "output regs must be grouped at top of stack");
malformed_asm = 1;
}
if (i != LAST_STACK_REG + 1)
{
error_for_asm (insn,
- "Implicitly popped regs must be grouped at top of stack");
+ "implicitly popped regs must be grouped at top of stack");
malformed_asm = 1;
}
- /* Enfore rule #3: If any input operand uses the "f" constraint, all
+ /* Enforce rule #3: If any input operand uses the "f" constraint, all
output constraints must use the "&" earlyclobber.
??? Detect this more deterministically by having constrain_asm_operands
if (operands_match_p (recog_data.operand[j], recog_data.operand[i]))
{
error_for_asm (insn,
- "Output operand %d must use `&' constraint", j);
+ "output operand %d must use `&' constraint", j);
malformed_asm = 1;
}
}
{
/* Avoid further trouble with this insn. */
PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
+ any_malformed_asm = true;
return 0;
}
placed. */
static int
-get_asm_operand_n_inputs (body)
- rtx body;
+get_asm_operand_n_inputs (rtx body)
{
if (GET_CODE (body) == SET && GET_CODE (SET_SRC (body)) == ASM_OPERANDS)
return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body));
return the REG. Otherwise, return 0. */
static rtx
-stack_result (decl)
- tree decl;
+stack_result (tree decl)
{
rtx result;
/* If the value is supposed to be returned in memory, then clearly
it is not returned in a stack register. */
- if (aggregate_value_p (DECL_RESULT (decl)))
+ if (aggregate_value_p (DECL_RESULT (decl), decl))
return 0;
- result = DECL_RTL (DECL_RESULT (decl));
- /* ?!? What is this code supposed to do? Can this code actually
- trigger if we kick out aggregates above? */
- if (result != 0
- && ! (GET_CODE (result) == REG
- && REGNO (result) < FIRST_PSEUDO_REGISTER))
+ result = DECL_RTL_IF_SET (DECL_RESULT (decl));
+ if (result != 0)
{
#ifdef FUNCTION_OUTGOING_VALUE
result
- = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl);
+ = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl);
#else
result = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (decl)), decl);
#endif
the desired hard REGNO. */
static void
-replace_reg (reg, regno)
- rtx *reg;
- int regno;
+replace_reg (rtx *reg, int regno)
{
if (regno < FIRST_STACK_REG || regno > LAST_STACK_REG
|| ! STACK_REG_P (*reg))
number REGNO from INSN. Remove only one such note. */
static void
-remove_regno_note (insn, note, regno)
- rtx insn;
- enum reg_note note;
- int regno;
+remove_regno_note (rtx insn, enum reg_note note, unsigned int regno)
{
- register rtx *note_link, this;
+ rtx *note_link, this;
- note_link = ®_NOTES(insn);
+ note_link = ®_NOTES (insn);
for (this = *note_link; this; this = XEXP (this, 1))
if (REG_NOTE_KIND (this) == note
&& REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno)
returned if the register is not found. */
static int
-get_hard_regnum (regstack, reg)
- stack regstack;
- rtx reg;
+get_hard_regnum (stack regstack, rtx reg)
{
int i;
return i >= 0 ? (FIRST_STACK_REG + regstack->top - i) : -1;
}
-
-/* Delete INSN from the RTL. Mark the insn, but don't remove it from
- the chain of insns. Doing so could confuse block_begin and block_end
- if this were the only insn in the block. */
-
-static void
-delete_insn_for_stacker (insn)
- rtx insn;
-{
- PUT_CODE (insn, NOTE);
- NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
- NOTE_SOURCE_FILE (insn) = 0;
-}
\f
/* Emit an insn to pop virtual register REG before or after INSN.
REGSTACK is the stack state after INSN and is updated to reflect this
cases the movdf pattern to pop. */
static rtx
-emit_pop_insn (insn, regstack, reg, where)
- rtx insn;
- stack regstack;
- rtx reg;
- enum emit_where where;
+emit_pop_insn (rtx insn, stack regstack, rtx reg, enum emit_where where)
{
rtx pop_insn, pop_rtx;
int hard_regno;
+ /* For complex types take care to pop both halves. These may survive in
+ CLOBBER and USE expressions. */
+ if (COMPLEX_MODE_P (GET_MODE (reg)))
+ {
+ rtx reg1 = FP_MODE_REG (REGNO (reg), DFmode);
+ rtx reg2 = FP_MODE_REG (REGNO (reg) + 1, DFmode);
+
+ pop_insn = NULL_RTX;
+ if (get_hard_regnum (regstack, reg1) >= 0)
+ pop_insn = emit_pop_insn (insn, regstack, reg1, where);
+ if (get_hard_regnum (regstack, reg2) >= 0)
+ pop_insn = emit_pop_insn (insn, regstack, reg2, where);
+ if (!pop_insn)
+ abort ();
+ return pop_insn;
+ }
+
hard_regno = get_hard_regnum (regstack, reg);
if (hard_regno < FIRST_STACK_REG)
FP_MODE_REG (FIRST_STACK_REG, DFmode));
if (where == EMIT_AFTER)
- pop_insn = emit_block_insn_after (pop_rtx, insn, current_block);
+ pop_insn = emit_insn_after (pop_rtx, insn);
else
- pop_insn = emit_block_insn_before (pop_rtx, insn, current_block);
+ pop_insn = emit_insn_before (pop_rtx, insn);
REG_NOTES (pop_insn)
= gen_rtx_EXPR_LIST (REG_DEAD, FP_MODE_REG (FIRST_STACK_REG, DFmode),
If REG is already at the top of the stack, no insn is emitted. */
static void
-emit_swap_insn (insn, regstack, reg)
- rtx insn;
- stack regstack;
- rtx reg;
+emit_swap_insn (rtx insn, stack regstack, rtx reg)
{
int hard_regno;
rtx swap_rtx;
/* Find the previous insn involving stack regs, but don't pass a
block boundary. */
i1 = NULL;
- if (current_block && insn != current_block->head)
+ if (current_block && insn != BB_HEAD (current_block))
{
rtx tmp = PREV_INSN (insn);
- rtx limit = PREV_INSN (current_block->head);
+ rtx limit = PREV_INSN (BB_HEAD (current_block));
while (tmp != limit)
{
if (GET_CODE (tmp) == CODE_LABEL
- || (GET_CODE (tmp) == NOTE
- && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BASIC_BLOCK)
+ || GET_CODE (tmp) == CALL_INSN
+ || NOTE_INSN_BASIC_BLOCK_P (tmp)
|| (GET_CODE (tmp) == INSN
&& stack_regs_mentioned (tmp)))
{
swap with, omit the swap. */
if (GET_CODE (i1dest) == REG && REGNO (i1dest) == FIRST_STACK_REG
- && GET_CODE (i1src) == REG && REGNO (i1src) == hard_regno - 1
+ && GET_CODE (i1src) == REG
+ && REGNO (i1src) == (unsigned) hard_regno - 1
&& find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
return;
/* If the previous insn wrote to the reg we are to swap with,
omit the swap. */
- if (GET_CODE (i1dest) == REG && REGNO (i1dest) == hard_regno
+ if (GET_CODE (i1dest) == REG && REGNO (i1dest) == (unsigned) hard_regno
&& GET_CODE (i1src) == REG && REGNO (i1src) == FIRST_STACK_REG
&& find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
return;
FP_MODE_REG (FIRST_STACK_REG, XFmode));
if (i1)
- emit_block_insn_after (swap_rtx, i1, current_block);
+ emit_insn_after (swap_rtx, i1);
else if (current_block)
- emit_block_insn_before (swap_rtx, current_block->head, current_block);
+ emit_insn_before (swap_rtx, BB_HEAD (current_block));
else
emit_insn_before (swap_rtx, insn);
}
\f
/* Handle a move to or from a stack register in PAT, which is in INSN.
- REGSTACK is the current stack. */
+ REGSTACK is the current stack. Return whether a control flow insn
+ was deleted in the process. */
-static void
-move_for_stack_reg (insn, regstack, pat)
- rtx insn;
- stack regstack;
- rtx pat;
+static bool
+move_for_stack_reg (rtx insn, stack regstack, rtx pat)
{
rtx *psrc = get_true_reg (&SET_SRC (pat));
rtx *pdest = get_true_reg (&SET_DEST (pat));
rtx src, dest;
rtx note;
+ bool control_flow_insn_deleted = false;
src = *psrc; dest = *pdest;
If so, just pop the src. */
if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
+ emit_pop_insn (insn, regstack, src, EMIT_AFTER);
+ else
{
- emit_pop_insn (insn, regstack, src, EMIT_AFTER);
-
- delete_insn_for_stacker (insn);
- return;
+ regstack->reg[i] = REGNO (dest);
+ SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
+ CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
}
- regstack->reg[i] = REGNO (dest);
-
- SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
- CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
-
- delete_insn_for_stacker (insn);
-
- return;
+ control_flow_insn_deleted |= control_flow_insn_p (insn);
+ delete_insn (insn);
+ return control_flow_insn_deleted;
}
/* The source reg does not die. */
if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
emit_pop_insn (insn, regstack, dest, EMIT_AFTER);
- delete_insn_for_stacker (insn);
- return;
+ control_flow_insn_deleted |= control_flow_insn_p (insn);
+ delete_insn (insn);
+ return control_flow_insn_deleted;
}
- /* The destination ought to be dead */
+ /* The destination ought to be dead. */
if (get_hard_regnum (regstack, dest) >= FIRST_STACK_REG)
abort ();
regstack->top--;
CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
}
- else if (GET_MODE (src) == XFmode && regstack->top < REG_STACK_SIZE - 1)
+ else if ((GET_MODE (src) == XFmode)
+ && regstack->top < REG_STACK_SIZE - 1)
{
/* A 387 cannot write an XFmode value to a MEM without
clobbering the source reg. The output code can handle
stack is not full, and then write the value to memory via
a pop. */
rtx push_rtx, push_insn;
- rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, XFmode);
+ rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, GET_MODE (src));
push_rtx = gen_movxf (top_stack_reg, top_stack_reg);
push_insn = emit_insn_before (push_rtx, insn);
stack. The stack mapping is changed to reflect that DEST is
now at top of stack. */
- /* The destination ought to be dead */
+ /* The destination ought to be dead. */
if (get_hard_regnum (regstack, dest) >= FIRST_STACK_REG)
abort ();
}
else
abort ();
+
+ return control_flow_insn_deleted;
}
\f
/* Swap the condition on a branch, if there is one. Return true if we
found a condition to swap. False if the condition was not used as
- such. */
+ such. */
static int
-swap_rtx_condition_1 (pat)
- rtx pat;
+swap_rtx_condition_1 (rtx pat)
{
- register const char *fmt;
- register int i, r = 0;
+ const char *fmt;
+ int i, r = 0;
if (GET_RTX_CLASS (GET_CODE (pat)) == '<')
{
{
if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
r |= swap_rtx_condition_1 (XVECEXP (pat, i, j));
}
static int
-swap_rtx_condition (insn)
- rtx insn;
+swap_rtx_condition (rtx insn)
{
rtx pat = PATTERN (insn);
if (GET_CODE (pat) == SET
&& GET_CODE (SET_SRC (pat)) == UNSPEC
- && XINT (SET_SRC (pat), 1) == 9)
+ && XINT (SET_SRC (pat), 1) == UNSPEC_FNSTSW)
{
rtx dest = SET_DEST (pat);
- /* Search forward looking for the first use of this value.
+ /* Search forward looking for the first use of this value.
Stop at block boundaries. */
- /* ??? This really cries for BLOCK_END! */
- while (1)
+ while (insn != BB_END (current_block))
{
insn = NEXT_INSN (insn);
- if (insn == NULL_RTX)
- return 0;
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
- && reg_mentioned_p (dest, insn))
+ if (INSN_P (insn) && reg_mentioned_p (dest, insn))
break;
- if (GET_CODE (insn) == JUMP_INSN)
- return 0;
- if (GET_CODE (insn) == CODE_LABEL)
+ if (GET_CODE (insn) == CALL_INSN)
return 0;
}
pat = PATTERN (insn);
if (GET_CODE (pat) != SET
|| GET_CODE (SET_SRC (pat)) != UNSPEC
- || XINT (SET_SRC (pat), 1) != 10
+ || XINT (SET_SRC (pat), 1) != UNSPEC_SAHF
|| ! dead_or_set_p (insn, dest))
return 0;
pat = PATTERN (insn);
}
- return swap_rtx_condition_1 (pat);
+ if (swap_rtx_condition_1 (pat))
+ {
+ int fail = 0;
+ INSN_CODE (insn) = -1;
+ if (recog_memoized (insn) == -1)
+ fail = 1;
+ /* In case the flags don't die here, recurse to try fix
+ following user too. */
+ else if (! dead_or_set_p (insn, ix86_flags_rtx))
+ {
+ insn = next_flags_user (insn);
+ if (!insn || !swap_rtx_condition (insn))
+ fail = 1;
+ }
+ if (fail)
+ {
+ swap_rtx_condition_1 (pat);
+ return 0;
+ }
+ return 1;
+ }
+ return 0;
}
/* Handle a comparison. Special care needs to be taken to avoid
set up. */
static void
-compare_for_stack_reg (insn, regstack, pat_src)
- rtx insn;
- stack regstack;
- rtx pat_src;
+compare_for_stack_reg (rtx insn, stack regstack, rtx pat_src)
{
rtx *src1, *src2;
rtx src1_note, src2_note;
}
\f
/* Substitute new registers in PAT, which is part of INSN. REGSTACK
- is the current register layout. */
+ is the current register layout. Return whether a control flow insn
+ was deleted in the process. */
-static void
-subst_stack_regs_pat (insn, regstack, pat)
- rtx insn;
- stack regstack;
- rtx pat;
+static bool
+subst_stack_regs_pat (rtx insn, stack regstack, rtx pat)
{
rtx *dest, *src;
+ bool control_flow_insn_deleted = false;
switch (GET_CODE (pat))
{
/* Deaths in USE insns can happen in non optimizing compilation.
Handle them by popping the dying register. */
src = get_true_reg (&XEXP (pat, 0));
- if (STACK_REG_P (*src)
- && find_regno_note (insn, REG_DEAD, REGNO (*src)))
- {
- emit_pop_insn (insn, regstack, *src, EMIT_AFTER);
- return;
- }
+ if (STACK_REG_P (*src)
+ && find_regno_note (insn, REG_DEAD, REGNO (*src)))
+ {
+ emit_pop_insn (insn, regstack, *src, EMIT_AFTER);
+ return control_flow_insn_deleted;
+ }
/* ??? Uninitialized USE should not happen. */
else if (get_hard_regnum (regstack, *src) == -1)
- abort();
+ abort ();
break;
case CLOBBER:
/* The fix_truncdi_1 pattern wants to be able to allocate
it's own scratch register. It does this by clobbering
an fp reg so that it is assured of an empty reg-stack
- register. If the register is live, kill it now.
+ register. If the register is live, kill it now.
Remove the DEAD/UNUSED note so we don't try to kill it
later too. */
abort ();
}
remove_note (insn, note);
- replace_reg (dest, LAST_STACK_REG);
+ replace_reg (dest, FIRST_STACK_REG + 1);
}
else
{
/* A top-level clobber with no REG_DEAD, and no hard-regnum
indicates an uninitialized value. Because reload removed
- all other clobbers, this must be due to a function
+ all other clobbers, this must be due to a function
returning without a value. Load up a NaN. */
if (! note
FP_MODE_REG (REGNO (*dest), SFmode),
nan);
PATTERN (insn) = pat;
- move_for_stack_reg (insn, regstack, pat);
+ control_flow_insn_deleted |= move_for_stack_reg (insn, regstack, pat);
+ }
+ if (! note && COMPLEX_MODE_P (GET_MODE (*dest))
+ && get_hard_regnum (regstack, FP_MODE_REG (REGNO (*dest), DFmode)) == -1)
+ {
+ pat = gen_rtx_SET (VOIDmode,
+ FP_MODE_REG (REGNO (*dest) + 1, SFmode),
+ nan);
+ PATTERN (insn) = pat;
+ control_flow_insn_deleted |= move_for_stack_reg (insn, regstack, pat);
}
}
}
case SET:
{
- rtx *src1 = (rtx *) NULL_PTR, *src2;
+ rtx *src1 = (rtx *) 0, *src2;
rtx src1_note, src2_note;
rtx pat_src;
&& (GET_CODE (*src) == REG || GET_CODE (*src) == MEM
|| GET_CODE (*src) == CONST_DOUBLE)))
{
- move_for_stack_reg (insn, regstack, pat);
+ control_flow_insn_deleted |= move_for_stack_reg (insn, regstack, pat);
break;
}
replace_reg (dest, get_hard_regnum (regstack, *dest));
}
- /* Keep operand 1 maching with destination. */
+ /* Keep operand 1 matching with destination. */
if (GET_RTX_CLASS (GET_CODE (pat_src)) == 'c'
&& REG_P (*src1) && REG_P (*src2)
&& REGNO (*src1) != REGNO (*dest))
{
- rtx tmp = *src1;
- *src1 = *src2;
- *src2 = tmp;
+ int tmp = REGNO (*src1);
+ replace_reg (src1, REGNO (*src2));
+ replace_reg (src2, tmp);
}
break;
case UNSPEC:
switch (XINT (pat_src, 1))
{
- case 1: /* sin */
- case 2: /* cos */
+ case UNSPEC_SIN:
+ case UNSPEC_COS:
+ case UNSPEC_FRNDINT:
+ case UNSPEC_F2XM1:
/* These insns only operate on the top of the stack. */
src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
replace_reg (src1, FIRST_STACK_REG);
break;
- case 10:
- /* (unspec [(unspec [(compare ..)] 9)] 10)
- Unspec 9 is fnstsw; unspec 10 is sahf. The combination
- matches the PPRO fcomi instruction. */
+ case UNSPEC_FPATAN:
+ case UNSPEC_FYL2X:
+ case UNSPEC_FSCALE:
+ /* These insns operate on the top two stack slots. */
+
+ src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
+ src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
+
+ src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
+ src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
+
+ {
+ struct stack_def temp_stack;
+ int regno, j, k, temp;
+
+ temp_stack = *regstack;
+
+ /* Place operand 1 at the top of stack. */
+ regno = get_hard_regnum (&temp_stack, *src1);
+ if (regno < 0)
+ abort ();
+ if (regno != FIRST_STACK_REG)
+ {
+ k = temp_stack.top - (regno - FIRST_STACK_REG);
+ j = temp_stack.top;
+
+ temp = temp_stack.reg[k];
+ temp_stack.reg[k] = temp_stack.reg[j];
+ temp_stack.reg[j] = temp;
+ }
+
+ /* Place operand 2 next on the stack. */
+ regno = get_hard_regnum (&temp_stack, *src2);
+ if (regno < 0)
+ abort ();
+ if (regno != FIRST_STACK_REG + 1)
+ {
+ k = temp_stack.top - (regno - FIRST_STACK_REG);
+ j = temp_stack.top - 1;
+
+ temp = temp_stack.reg[k];
+ temp_stack.reg[k] = temp_stack.reg[j];
+ temp_stack.reg[j] = temp;
+ }
+
+ change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
+ }
+
+ replace_reg (src1, FIRST_STACK_REG);
+ replace_reg (src2, FIRST_STACK_REG + 1);
+
+ if (src1_note)
+ replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
+ if (src2_note)
+ replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
+
+ /* Pop both input operands from the stack. */
+ CLEAR_HARD_REG_BIT (regstack->reg_set,
+ regstack->reg[regstack->top]);
+ CLEAR_HARD_REG_BIT (regstack->reg_set,
+ regstack->reg[regstack->top - 1]);
+ regstack->top -= 2;
+
+ /* Push the result back onto the stack. */
+ regstack->reg[++regstack->top] = REGNO (*dest);
+ SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
+ replace_reg (dest, FIRST_STACK_REG);
+ break;
+
+ case UNSPEC_SAHF:
+ /* (unspec [(unspec [(compare)] UNSPEC_FNSTSW)] UNSPEC_SAHF)
+ The combination matches the PPRO fcomi instruction. */
pat_src = XVECEXP (pat_src, 0, 0);
if (GET_CODE (pat_src) != UNSPEC
- || XINT (pat_src, 1) != 9)
+ || XINT (pat_src, 1) != UNSPEC_FNSTSW)
abort ();
/* FALLTHRU */
- case 9:
- /* (unspec [(compare ..)] 9) */
+ case UNSPEC_FNSTSW:
/* Combined fcomp+fnstsw generated for doing well with
CSE. When optimizing this would have been broken
up before now. */
break;
case IF_THEN_ELSE:
- /* This insn requires the top of stack to be the destination. */
+ /* This insn requires the top of stack to be the destination. */
+
+ src1 = get_true_reg (&XEXP (pat_src, 1));
+ src2 = get_true_reg (&XEXP (pat_src, 2));
+
+ src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
+ src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
/* If the comparison operator is an FP comparison operator,
it is handled correctly by compare_for_stack_reg () who
will move the destination to the top of stack. But if the
comparison operator is not an FP comparison operator, we
- have to handle it here. */
+ have to handle it here. */
if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG
&& REGNO (*dest) != regstack->reg[regstack->top])
- emit_swap_insn (insn, regstack, *dest);
-
- src1 = get_true_reg (&XEXP (pat_src, 1));
- src2 = get_true_reg (&XEXP (pat_src, 2));
-
- src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
- src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
+ {
+ /* In case one of operands is the top of stack and the operands
+ dies, it is safe to make it the destination operand by
+ reversing the direction of cmove and avoid fxch. */
+ if ((REGNO (*src1) == regstack->reg[regstack->top]
+ && src1_note)
+ || (REGNO (*src2) == regstack->reg[regstack->top]
+ && src2_note))
+ {
+ int idx1 = (get_hard_regnum (regstack, *src1)
+ - FIRST_STACK_REG);
+ int idx2 = (get_hard_regnum (regstack, *src2)
+ - FIRST_STACK_REG);
+
+ /* Make reg-stack believe that the operands are already
+ swapped on the stack */
+ regstack->reg[regstack->top - idx1] = REGNO (*src2);
+ regstack->reg[regstack->top - idx2] = REGNO (*src1);
+
+ /* Reverse condition to compensate the operand swap.
+ i386 do have comparison always reversible. */
+ PUT_CODE (XEXP (pat_src, 0),
+ reversed_comparison_code (XEXP (pat_src, 0), insn));
+ }
+ else
+ emit_swap_insn (insn, regstack, *dest);
+ }
{
rtx src_note [3];
EMIT_AFTER);
}
else
- {
- CLEAR_HARD_REG_BIT (regstack->reg_set, regno);
- replace_reg (&XEXP (src_note[i], 0), FIRST_STACK_REG);
- regstack->top--;
- }
+ /* Top of stack never dies, as it is the
+ destination. */
+ abort ();
}
}
/* Make dest the top of stack. Add dest to regstack if
- not present. */
+ not present. */
if (get_hard_regnum (regstack, *dest) < FIRST_STACK_REG)
- regstack->reg[++regstack->top] = REGNO (*dest);
+ regstack->reg[++regstack->top] = REGNO (*dest);
SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
replace_reg (dest, FIRST_STACK_REG);
break;
default:
break;
}
+
+ return control_flow_insn_deleted;
}
\f
/* Substitute hard regnums for any stack regs in INSN, which has
requirements, since record_asm_stack_regs removes any problem asm. */
static void
-subst_asm_stack_regs (insn, regstack)
- rtx insn;
- stack regstack;
+subst_asm_stack_regs (rtx insn, stack regstack)
{
rtx body = PATTERN (insn);
int alt;
n_inputs = get_asm_operand_n_inputs (body);
n_outputs = recog_data.n_operands - n_inputs;
-
+
if (alt < 0)
abort ();
for (i = 0, note = REG_NOTES (insn); note; note = XEXP (note, 1))
i++;
- note_reg = (rtx *) alloca (i * sizeof (rtx));
- note_loc = (rtx **) alloca (i * sizeof (rtx *));
- note_kind = (enum reg_note *) alloca (i * sizeof (enum reg_note));
+ note_reg = alloca (i * sizeof (rtx));
+ note_loc = alloca (i * sizeof (rtx *));
+ note_kind = alloca (i * sizeof (enum reg_note));
n_notes = 0;
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
if (GET_CODE (body) == PARALLEL)
{
- clobber_reg = (rtx *) alloca (XVECLEN (body, 0) * sizeof (rtx));
- clobber_loc = (rtx **) alloca (XVECLEN (body, 0) * sizeof (rtx *));
+ clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx));
+ clobber_loc = alloca (XVECLEN (body, 0) * sizeof (rtx *));
for (i = 0; i < XVECLEN (body, 0); i++)
if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
if (regno < 0)
abort ();
- if (regno != REGNO (recog_data.operand[i]))
+ if ((unsigned int) regno != REGNO (recog_data.operand[i]))
{
/* recog_data.operand[i] is not in the right place. Find
it and swap it with whatever is already in I's place.
for (j = 0; j < n_outputs; j++)
if (STACK_REG_P (recog_data.operand[j])
- && REGNO (recog_data.operand[j]) == i)
+ && REGNO (recog_data.operand[j]) == (unsigned) i)
{
regstack->reg[++regstack->top] = i;
SET_HARD_REG_BIT (regstack->reg_set, i);
/* Substitute stack hard reg numbers for stack virtual registers in
INSN. Non-stack register numbers are not changed. REGSTACK is the
current stack content. Insns may be emitted as needed to arrange the
- stack for the 387 based on the contents of the insn. */
+ stack for the 387 based on the contents of the insn. Return whether
+ a control flow insn was deleted in the process. */
-static void
-subst_stack_regs (insn, regstack)
- rtx insn;
- stack regstack;
+static bool
+subst_stack_regs (rtx insn, stack regstack)
{
- register rtx *note_link, note;
- register int i;
+ rtx *note_link, note;
+ bool control_flow_insn_deleted = false;
+ int i;
if (GET_CODE (insn) == CALL_INSN)
{
Any REG_UNUSED notes will be handled by subst_asm_stack_regs. */
subst_asm_stack_regs (insn, regstack);
- return;
+ return control_flow_insn_deleted;
}
if (GET_CODE (PATTERN (insn)) == PARALLEL)
for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
{
if (stack_regs_mentioned_p (XVECEXP (PATTERN (insn), 0, i)))
- subst_stack_regs_pat (insn, regstack,
- XVECEXP (PATTERN (insn), 0, i));
+ control_flow_insn_deleted
+ |= subst_stack_regs_pat (insn, regstack,
+ XVECEXP (PATTERN (insn), 0, i));
}
else
- subst_stack_regs_pat (insn, regstack, PATTERN (insn));
+ control_flow_insn_deleted
+ |= subst_stack_regs_pat (insn, regstack, PATTERN (insn));
}
/* subst_stack_regs_pat may have deleted a no-op insn. If so, any
REG_UNUSED will already have been dealt with, so just return. */
- if (GET_CODE (insn) == NOTE)
- return;
+ if (GET_CODE (insn) == NOTE || INSN_DELETED_P (insn))
+ return control_flow_insn_deleted;
/* If there is a REG_UNUSED note on a stack register on this insn,
the indicated reg must be popped. The REG_UNUSED note is removed,
since the form of the newly emitted pop insn references the reg,
making it no longer `unset'. */
- note_link = ®_NOTES(insn);
+ note_link = ®_NOTES (insn);
for (note = *note_link; note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_UNUSED && STACK_REG_P (XEXP (note, 0)))
{
}
else
note_link = &XEXP (note, 1);
+
+ return control_flow_insn_deleted;
}
\f
/* Change the organization of the stack so that it fits a new basic
is no longer needed once this has executed. */
static void
-change_stack (insn, old, new, where)
- rtx insn;
- stack old;
- stack new;
- enum emit_where where;
+change_stack (rtx insn, stack old, stack new, enum emit_where where)
{
int reg;
int update_end = 0;
if (where == EMIT_AFTER)
{
- if (current_block && current_block->end == insn)
+ if (current_block && BB_END (current_block) == insn)
update_end = 1;
insn = NEXT_INSN (insn);
}
abort ();
/* If the stack is not empty (new->top != -1), loop here emitting
- swaps until the stack is correct.
+ swaps until the stack is correct.
The worst case number of swaps emitted is N + 2, where N is the
depth of the stack. In some cases, the reg at the top of
}
if (update_end)
- current_block->end = PREV_INSN (insn);
+ BB_END (current_block) = PREV_INSN (insn);
}
\f
/* Print stack configuration. */
static void
-print_stack (file, s)
- FILE *file;
- stack s;
+print_stack (FILE *file, stack s)
{
if (! file)
return;
}
\f
/* This function was doing life analysis. We now let the regular live
- code do it's job, so we only need to check some extra invariants
+ code do it's job, so we only need to check some extra invariants
that reg-stack expects. Primary among these being that all registers
are initialized before use.
commit_edge_insertions needs to be called. */
static int
-convert_regs_entry ()
+convert_regs_entry (void)
{
- int inserted = 0, i;
+ int inserted = 0;
edge e;
+ basic_block block;
- for (i = n_basic_blocks - 1; i >= 0; --i)
+ FOR_EACH_BB_REVERSE (block)
{
- basic_block block = BASIC_BLOCK (i);
block_info bi = BLOCK_INFO (block);
int reg;
-
+
/* Set current register status at last instruction `uninitialized'. */
bi->stack_in.top = -2;
-
+
/* Copy live_at_end and live_at_start into temporaries. */
for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; reg++)
{
}
}
- /* Load something into each stack register live at function entry.
+ /* Load something into each stack register live at function entry.
Such live registers can be caused by uninitialized variables or
- functions not returning values on all paths. In order to keep
+ functions not returning values on all paths. In order to keep
the push/pop code happy, and to not scrog the register stack, we
- must put something in these registers. Use a QNaN.
+ must put something in these registers. Use a QNaN.
- Note that we are insertting converted code here. This code is
+ Note that we are inserting converted code here. This code is
never seen by the convert_regs pass. */
for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next)
be `empty', or the function return value at top-of-stack. */
static void
-convert_regs_exit ()
+convert_regs_exit (void)
{
int value_reg_low, value_reg_high;
stack output_stack;
output_stack->top = value_reg_high - value_reg_low;
for (reg = value_reg_low; reg <= value_reg_high; ++reg)
{
- output_stack->reg[reg - value_reg_low] = reg;
+ output_stack->reg[value_reg_high - reg] = reg;
SET_HARD_REG_BIT (output_stack->reg_set, reg);
}
}
}
+/* Adjust the stack of this block on exit to match the stack of the
+ target block, or copy stack info into the stack of the successor
+ of the successor hasn't been processed yet. */
+static bool
+compensate_edge (edge e, FILE *file)
+{
+ basic_block block = e->src, target = e->dest;
+ block_info bi = BLOCK_INFO (block);
+ struct stack_def regstack, tmpstack;
+ stack target_stack = &BLOCK_INFO (target)->stack_in;
+ int reg;
+
+ current_block = block;
+ regstack = bi->stack_out;
+ if (file)
+ fprintf (file, "Edge %d->%d: ", block->index, target->index);
+
+ if (target_stack->top == -2)
+ {
+ /* The target block hasn't had a stack order selected.
+ We need merely ensure that no pops are needed. */
+ for (reg = regstack.top; reg >= 0; --reg)
+ if (!TEST_HARD_REG_BIT (target_stack->reg_set, regstack.reg[reg]))
+ break;
+
+ if (reg == -1)
+ {
+ if (file)
+ fprintf (file, "new block; copying stack position\n");
+
+ /* change_stack kills values in regstack. */
+ tmpstack = regstack;
+
+ change_stack (BB_END (block), &tmpstack, target_stack, EMIT_AFTER);
+ return false;
+ }
+
+ if (file)
+ fprintf (file, "new block; pops needed\n");
+ }
+ else
+ {
+ if (target_stack->top == regstack.top)
+ {
+ for (reg = target_stack->top; reg >= 0; --reg)
+ if (target_stack->reg[reg] != regstack.reg[reg])
+ break;
+
+ if (reg == -1)
+ {
+ if (file)
+ fprintf (file, "no changes needed\n");
+ return false;
+ }
+ }
+
+ if (file)
+ {
+ fprintf (file, "correcting stack to ");
+ print_stack (file, target_stack);
+ }
+ }
+
+ /* Care for non-call EH edges specially. The normal return path have
+ values in registers. These will be popped en masse by the unwind
+ library. */
+ if ((e->flags & (EDGE_EH | EDGE_ABNORMAL_CALL)) == EDGE_EH)
+ target_stack->top = -1;
+
+ /* Other calls may appear to have values live in st(0), but the
+ abnormal return path will not have actually loaded the values. */
+ else if (e->flags & EDGE_ABNORMAL_CALL)
+ {
+ /* Assert that the lifetimes are as we expect -- one value
+ live at st(0) on the end of the source block, and no
+ values live at the beginning of the destination block. */
+ HARD_REG_SET tmp;
+
+ CLEAR_HARD_REG_SET (tmp);
+ GO_IF_HARD_REG_EQUAL (target_stack->reg_set, tmp, eh1);
+ abort ();
+ eh1:
+
+ /* We are sure that there is st(0) live, otherwise we won't compensate.
+ For complex return values, we may have st(1) live as well. */
+ SET_HARD_REG_BIT (tmp, FIRST_STACK_REG);
+ if (TEST_HARD_REG_BIT (regstack.reg_set, FIRST_STACK_REG + 1))
+ SET_HARD_REG_BIT (tmp, FIRST_STACK_REG + 1);
+ GO_IF_HARD_REG_EQUAL (regstack.reg_set, tmp, eh2);
+ abort ();
+ eh2:
+
+ target_stack->top = -1;
+ }
+
+ /* It is better to output directly to the end of the block
+ instead of to the edge, because emit_swap can do minimal
+ insn scheduling. We can do this when there is only one
+ edge out, and it is not abnormal. */
+ else if (block->succ->succ_next == NULL && !(e->flags & EDGE_ABNORMAL))
+ {
+ /* change_stack kills values in regstack. */
+ tmpstack = regstack;
+
+ change_stack (BB_END (block), &tmpstack, target_stack,
+ (GET_CODE (BB_END (block)) == JUMP_INSN
+ ? EMIT_BEFORE : EMIT_AFTER));
+ }
+ else
+ {
+ rtx seq, after;
+
+ /* We don't support abnormal edges. Global takes care to
+ avoid any live register across them, so we should never
+ have to insert instructions on such edges. */
+ if (e->flags & EDGE_ABNORMAL)
+ abort ();
+
+ current_block = NULL;
+ start_sequence ();
+
+ /* ??? change_stack needs some point to emit insns after. */
+ after = emit_note (NOTE_INSN_DELETED);
+
+ tmpstack = regstack;
+ change_stack (after, &tmpstack, target_stack, EMIT_BEFORE);
+
+ seq = get_insns ();
+ end_sequence ();
+
+ insert_insn_on_edge (seq, e);
+ return true;
+ }
+ return false;
+}
+
/* Convert stack register references in one block. */
static int
-convert_regs_1 (file, block)
- FILE *file;
- basic_block block;
+convert_regs_1 (FILE *file, basic_block block)
{
- struct stack_def regstack, tmpstack;
+ struct stack_def regstack;
block_info bi = BLOCK_INFO (block);
- int inserted, reg;
+ int deleted, inserted, reg;
rtx insn, next;
- edge e;
+ edge e, beste = NULL;
+ bool control_flow_insn_deleted = false;
+
+ inserted = 0;
+ deleted = 0;
+ any_malformed_asm = false;
+
+ /* Find the edge we will copy stack from. It should be the most frequent
+ one as it will get cheapest after compensation code is generated,
+ if multiple such exists, take one with largest count, prefer critical
+ one (as splitting critical edges is more expensive), or one with lowest
+ index, to avoid random changes with different orders of the edges. */
+ for (e = block->pred; e ; e = e->pred_next)
+ {
+ if (e->flags & EDGE_DFS_BACK)
+ ;
+ else if (! beste)
+ beste = e;
+ else if (EDGE_FREQUENCY (beste) < EDGE_FREQUENCY (e))
+ beste = e;
+ else if (EDGE_FREQUENCY (beste) > EDGE_FREQUENCY (e))
+ ;
+ else if (beste->count < e->count)
+ beste = e;
+ else if (beste->count > e->count)
+ ;
+ else if ((EDGE_CRITICAL_P (e) != 0)
+ != (EDGE_CRITICAL_P (beste) != 0))
+ {
+ if (EDGE_CRITICAL_P (e))
+ beste = e;
+ }
+ else if (e->src->index < beste->src->index)
+ beste = e;
+ }
+
+ /* Initialize stack at block entry. */
+ if (bi->stack_in.top == -2)
+ {
+ if (beste)
+ inserted |= compensate_edge (beste, file);
+ else
+ {
+ /* No predecessors. Create an arbitrary input stack. */
+ int reg;
+
+ bi->stack_in.top = -1;
+ for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg)
+ if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg))
+ bi->stack_in.reg[++bi->stack_in.top] = reg;
+ }
+ }
+ else
+ /* Entry blocks do have stack already initialized. */
+ beste = NULL;
current_block = block;
-
+
if (file)
{
fprintf (file, "\nBasic block %d\nInput stack: ", block->index);
/* Process all insns in this block. Keep track of NEXT so that we
don't process insns emitted while substituting in INSN. */
- next = block->head;
+ next = BB_HEAD (block);
regstack = bi->stack_in;
do
{
/* Ensure we have not missed a block boundary. */
if (next == NULL)
abort ();
- if (insn == block->end)
+ if (insn == BB_END (block))
next = NULL;
/* Don't bother processing unless there is a stack reg
INSN_UID (insn));
print_stack (file, ®stack);
}
- subst_stack_regs (insn, ®stack);
+ control_flow_insn_deleted |= subst_stack_regs (insn, ®stack);
}
}
while (next);
print_stack (file, ®stack);
}
- insn = block->end;
+ insn = BB_END (block);
if (GET_CODE (insn) == JUMP_INSN)
insn = PREV_INSN (insn);
set = gen_rtx_SET (VOIDmode, FP_MODE_REG (reg, SFmode),
nan);
- insn = emit_block_insn_after (set, insn, block);
- subst_stack_regs (insn, ®stack);
+ insn = emit_insn_after (set, insn);
+ control_flow_insn_deleted |= subst_stack_regs (insn, ®stack);
}
}
-
- /* Something failed if the stack lives don't match. */
+
+ /* Amongst the insns possibly deleted during the substitution process above,
+ might have been the only trapping insn in the block. We purge the now
+ possibly dead EH edges here to avoid an ICE from fixup_abnormal_edges,
+ called at the end of convert_regs. The order in which we process the
+ blocks ensures that we never delete an already processed edge.
+
+ Note that, at this point, the CFG may have been damaged by the emission
+ of instructions after an abnormal call, which moves the basic block end
+ (and is the reason why we call fixup_abnormal_edges later). So we must
+ be sure that the trapping insn has been deleted before trying to purge
+ dead edges, otherwise we risk purging valid edges.
+
+ ??? We are normally supposed not to delete trapping insns, so we pretend
+ that the insns deleted above don't actually trap. It would have been
+ better to detect this earlier and avoid creating the EH edge in the first
+ place, still, but we don't have enough information at that time. */
+
+ if (control_flow_insn_deleted)
+ purge_dead_edges (block);
+
+ /* Something failed if the stack lives don't match. If we had malformed
+ asms, we zapped the instruction itself, but that didn't produce the
+ same pattern of register kills as before. */
GO_IF_HARD_REG_EQUAL (regstack.reg_set, bi->out_reg_set, win);
- abort ();
+ if (!any_malformed_asm)
+ abort ();
win:
+ bi->stack_out = regstack;
- /* Adjust the stack of this block on exit to match the stack of the
- target block, or copy stack info into the stack of the successor
- of the successor hasn't been processed yet. */
- inserted = 0;
+ /* Compensate the back edges, as those wasn't visited yet. */
for (e = block->succ; e ; e = e->succ_next)
{
- basic_block target = e->dest;
- stack target_stack = &BLOCK_INFO (target)->stack_in;
-
- if (file)
- fprintf (file, "Edge to block %d: ", target->index);
-
- if (target_stack->top == -2)
- {
- /* The target block hasn't had a stack order selected.
- We need merely ensure that no pops are needed. */
- for (reg = regstack.top; reg >= 0; --reg)
- if (! TEST_HARD_REG_BIT (target_stack->reg_set,
- regstack.reg[reg]))
- break;
-
- if (reg == -1)
- {
- if (file)
- fprintf (file, "new block; copying stack position\n");
-
- /* change_stack kills values in regstack. */
- tmpstack = regstack;
-
- change_stack (block->end, &tmpstack,
- target_stack, EMIT_AFTER);
- continue;
- }
-
- if (file)
- fprintf (file, "new block; pops needed\n");
- }
- else
- {
- if (target_stack->top == regstack.top)
- {
- for (reg = target_stack->top; reg >= 0; --reg)
- if (target_stack->reg[reg] != regstack.reg[reg])
- break;
-
- if (reg == -1)
- {
- if (file)
- fprintf (file, "no changes needed\n");
- continue;
- }
- }
-
- if (file)
- {
- fprintf (file, "correcting stack to ");
- print_stack (file, target_stack);
- }
- }
-
- /* Care for EH edges specially. The normal return path may return
- a value in st(0), but the EH path will not, and there's no need
- to add popping code to the edge. */
- if (e->flags & (EDGE_EH | EDGE_ABNORMAL_CALL))
+ if (e->flags & EDGE_DFS_BACK
+ || (e->dest == EXIT_BLOCK_PTR))
{
- /* Assert that the lifetimes are as we expect -- one value
- live at st(0) on the end of the source block, and no
- values live at the beginning of the destination block. */
- HARD_REG_SET tmp;
-
- CLEAR_HARD_REG_SET (tmp);
- GO_IF_HARD_REG_EQUAL (target_stack->reg_set, tmp, eh1);
- abort();
- eh1:
-
- SET_HARD_REG_BIT (tmp, FIRST_STACK_REG);
- GO_IF_HARD_REG_EQUAL (regstack.reg_set, tmp, eh2);
- abort();
- eh2:
-
- target_stack->top = -1;
- }
-
- /* It is better to output directly to the end of the block
- instead of to the edge, because emit_swap can do minimal
- insn scheduling. We can do this when there is only one
- edge out, and it is not abnormal. */
- else if (block->succ->succ_next == NULL
- && ! (e->flags & EDGE_ABNORMAL))
- {
- /* change_stack kills values in regstack. */
- tmpstack = regstack;
-
- change_stack (block->end, &tmpstack, target_stack,
- (GET_CODE (block->end) == JUMP_INSN
- ? EMIT_BEFORE : EMIT_AFTER));
+ if (!BLOCK_INFO (e->dest)->done
+ && e->dest != block)
+ abort ();
+ inserted |= compensate_edge (e, file);
}
- else
+ }
+ for (e = block->pred; e ; e = e->pred_next)
+ {
+ if (e != beste && !(e->flags & EDGE_DFS_BACK)
+ && e->src != ENTRY_BLOCK_PTR)
{
- rtx seq, after;
-
- /* We don't support abnormal edges. Global takes care to
- avoid any live register across them, so we should never
- have to insert instructions on such edges. */
- if (e->flags & EDGE_ABNORMAL)
+ if (!BLOCK_INFO (e->src)->done)
abort ();
-
- current_block = NULL;
- start_sequence ();
-
- /* ??? change_stack needs some point to emit insns after.
- Also needed to keep gen_sequence from returning a
- pattern as opposed to a sequence, which would lose
- REG_DEAD notes. */
- after = emit_note (NULL, NOTE_INSN_DELETED);
-
- tmpstack = regstack;
- change_stack (after, &tmpstack, target_stack, EMIT_BEFORE);
-
- seq = gen_sequence ();
- end_sequence ();
-
- insert_insn_on_edge (seq, e);
- inserted = 1;
- current_block = block;
+ inserted |= compensate_edge (e, file);
}
}
/* Convert registers in all blocks reachable from BLOCK. */
static int
-convert_regs_2 (file, block)
- FILE *file;
- basic_block block;
+convert_regs_2 (FILE *file, basic_block block)
{
basic_block *stack, *sp;
int inserted;
- stack = (basic_block *) xmalloc (sizeof (*stack) * n_basic_blocks);
+ /* We process the blocks in a top-down manner, in a way such that one block
+ is only processed after all its predecessors. The number of predecessors
+ of every block has already been computed. */
+
+ stack = xmalloc (sizeof (*stack) * n_basic_blocks);
sp = stack;
*sp++ = block;
- BLOCK_INFO (block)->done = 1;
inserted = 0;
do
edge e;
block = *--sp;
- inserted |= convert_regs_1 (file, block);
+
+ /* Processing BLOCK is achieved by convert_regs_1, which may purge
+ some dead EH outgoing edge after the deletion of the trapping
+ insn inside the block. Since the number of predecessors of
+ BLOCK's successors was computed based on the initial edge set,
+ we check the necessity to process some of these successors
+ before such an edge deletion may happen. However, there is
+ a pitfall: if BLOCK is the only predecessor of a successor and
+ the edge between them happens to be deleted, the successor
+ becomes unreachable and should not be processed. The problem
+ is that there is no way to preventively detect this case so we
+ stack the successor in all cases and hand over the task of
+ fixing up the discrepancy to convert_regs_1. */
for (e = block->succ; e ; e = e->succ_next)
- if (! BLOCK_INFO (e->dest)->done)
+ if (! (e->flags & EDGE_DFS_BACK))
{
- *sp++ = e->dest;
- BLOCK_INFO (e->dest)->done = 1;
+ BLOCK_INFO (e->dest)->predecessors--;
+ if (!BLOCK_INFO (e->dest)->predecessors)
+ *sp++ = e->dest;
}
+
+ inserted |= convert_regs_1 (file, block);
+ BLOCK_INFO (block)->done = 1;
}
while (sp != stack);
to the stack-like registers the 387 uses. */
static int
-convert_regs (file)
- FILE *file;
+convert_regs (FILE *file)
{
- int inserted, i;
+ int inserted;
+ basic_block b;
edge e;
/* Initialize uninitialized registers on function entry. */
/* Process all blocks reachable from all entry points. */
for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next)
inserted |= convert_regs_2 (file, e->dest);
-
- /* ??? Process all unreachable blocks. Though there's no excuse
+
+ /* ??? Process all unreachable blocks. Though there's no excuse
for keeping these even when not optimizing. */
- for (i = 0; i < n_basic_blocks; ++i)
+ FOR_EACH_BB (b)
{
- basic_block b = BASIC_BLOCK (i);
block_info bi = BLOCK_INFO (b);
if (! bi->done)
- {
- int reg;
-
- /* Create an arbitrary input stack. */
- bi->stack_in.top = -1;
- for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg)
- if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg))
- bi->stack_in.reg[++bi->stack_in.top] = reg;
-
- inserted |= convert_regs_2 (file, b);
- }
+ inserted |= convert_regs_2 (file, b);
}
+ clear_aux_for_blocks ();
+ fixup_abnormal_edges ();
if (inserted)
commit_edge_insertions ();
return inserted;
}
#endif /* STACK_REGS */
+
+#include "gt-reg-stack.h"