/* Allocate registers within a basic block, for GNU compiler.
- Copyright (C) 1987, 88, 91, 93-6, 1997 Free Software Foundation, Inc.
+ Copyright (C) 1987, 1988, 1991, 1993, 1994, 1995, 1996, 1997, 1998,
+ 1999, 2000 Free Software Foundation, Inc.
This file is part of GNU CC.
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
-
/* Allocation of hard register numbers to pseudo registers is done in
two passes. In this pass we consider only regs that are born and
die once within one basic block. We do this one basic block at a
Tying is represented with "quantity numbers".
A non-tied register is given a new quantity number.
Tied registers have the same quantity number.
-
+
We have provision to exempt registers, even when they are contained
within the block, that can be tied to others that are not contained in it.
This is so that global_alloc could process them both and tie them then.
But this is currently disabled since tying in global_alloc is not
yet implemented. */
-/* Pseudos allocated here cannot be reallocated by global.c if the hard
- register is used as a spill register. So we don't allocate such pseudos
+/* Pseudos allocated here can be reallocated by global.c if the hard register
+ is used as a spill register. Currently we don't allocate such pseudos
here if their preferred class is likely to be used by spills. */
-#include <stdio.h>
#include "config.h"
+#include "system.h"
#include "rtl.h"
+#include "tm_p.h"
#include "flags.h"
+#include "hard-reg-set.h"
#include "basic-block.h"
#include "regs.h"
-#include "hard-reg-set.h"
+#include "function.h"
#include "insn-config.h"
+#include "insn-attr.h"
#include "recog.h"
#include "output.h"
+#include "toplev.h"
\f
/* Next quantity number available for allocation. */
static int next_qty;
-/* In all the following vectors indexed by quantity number. */
+/* Information we maitain about each quantity. */
+struct qty
+{
+ /* The number of refs to quantity Q. */
-/* Element Q is the hard reg number chosen for quantity Q,
- or -1 if none was found. */
+ int n_refs;
-static short *qty_phys_reg;
+ /* Insn number (counting from head of basic block)
+ where quantity Q was born. -1 if birth has not been recorded. */
-/* We maintain two hard register sets that indicate suggested hard registers
- for each quantity. The first, qty_phys_copy_sugg, contains hard registers
- that are tied to the quantity by a simple copy. The second contains all
- hard registers that are tied to the quantity via an arithmetic operation.
+ int birth;
- The former register set is given priority for allocation. This tends to
- eliminate copy insns. */
+ /* Insn number (counting from head of basic block)
+ where given quantity died. Due to the way tying is done,
+ and the fact that we consider in this pass only regs that die but once,
+ a quantity can die only once. Each quantity's life span
+ is a set of consecutive insns. -1 if death has not been recorded. */
-/* Element Q is a set of hard registers that are suggested for quantity Q by
- copy insns. */
+ int death;
-static HARD_REG_SET *qty_phys_copy_sugg;
+ /* Number of words needed to hold the data in given quantity.
+ This depends on its machine mode. It is used for these purposes:
+ 1. It is used in computing the relative importances of qtys,
+ which determines the order in which we look for regs for them.
+ 2. It is used in rules that prevent tying several registers of
+ different sizes in a way that is geometrically impossible
+ (see combine_regs). */
-/* Element Q is a set of hard registers that are suggested for quantity Q by
- arithmetic insns. */
+ int size;
-static HARD_REG_SET *qty_phys_sugg;
+ /* Number of times a reg tied to given qty lives across a CALL_INSN. */
-/* Element Q is the number of suggested registers in qty_phys_copy_sugg. */
+ int n_calls_crossed;
-static short *qty_phys_num_copy_sugg;
+ /* The register number of one pseudo register whose reg_qty value is Q.
+ This register should be the head of the chain
+ maintained in reg_next_in_qty. */
-/* Element Q is the number of suggested registers in qty_phys_sugg. */
+ int first_reg;
-static short *qty_phys_num_sugg;
+ /* Reg class contained in (smaller than) the preferred classes of all
+ the pseudo regs that are tied in given quantity.
+ This is the preferred class for allocating that quantity. */
-/* Element Q is the number of refs to quantity Q. */
+ enum reg_class min_class;
-static int *qty_n_refs;
+ /* Register class within which we allocate given qty if we can't get
+ its preferred class. */
-/* Element Q is a reg class contained in (smaller than) the
- preferred classes of all the pseudo regs that are tied in quantity Q.
- This is the preferred class for allocating that quantity. */
+ enum reg_class alternate_class;
-static enum reg_class *qty_min_class;
+ /* This holds the mode of the registers that are tied to given qty,
+ or VOIDmode if registers with differing modes are tied together. */
-/* Insn number (counting from head of basic block)
- where quantity Q was born. -1 if birth has not been recorded. */
+ enum machine_mode mode;
-static int *qty_birth;
+ /* the hard reg number chosen for given quantity,
+ or -1 if none was found. */
-/* Insn number (counting from head of basic block)
- where quantity Q died. Due to the way tying is done,
- and the fact that we consider in this pass only regs that die but once,
- a quantity can die only once. Each quantity's life span
- is a set of consecutive insns. -1 if death has not been recorded. */
+ short phys_reg;
-static int *qty_death;
+ /* Nonzero if this quantity has been used in a SUBREG in some
+ way that is illegal. */
-/* Number of words needed to hold the data in quantity Q.
- This depends on its machine mode. It is used for these purposes:
- 1. It is used in computing the relative importances of qtys,
- which determines the order in which we look for regs for them.
- 2. It is used in rules that prevent tying several registers of
- different sizes in a way that is geometrically impossible
- (see combine_regs). */
+ char changes_mode;
-static int *qty_size;
+};
-/* This holds the mode of the registers that are tied to qty Q,
- or VOIDmode if registers with differing modes are tied together. */
+static struct qty *qty;
-static enum machine_mode *qty_mode;
+/* These fields are kept separately to speedup their clearing. */
-/* Number of times a reg tied to qty Q lives across a CALL_INSN. */
+/* We maintain two hard register sets that indicate suggested hard registers
+ for each quantity. The first, phys_copy_sugg, contains hard registers
+ that are tied to the quantity by a simple copy. The second contains all
+ hard registers that are tied to the quantity via an arithmetic operation.
-static int *qty_n_calls_crossed;
+ The former register set is given priority for allocation. This tends to
+ eliminate copy insns. */
-/* Register class within which we allocate qty Q if we can't get
- its preferred class. */
+/* Element Q is a set of hard registers that are suggested for quantity Q by
+ copy insns. */
-static enum reg_class *qty_alternate_class;
+static HARD_REG_SET *qty_phys_copy_sugg;
-/* Element Q is the SCRATCH expression for which this quantity is being
- allocated or 0 if this quantity is allocating registers. */
+/* Element Q is a set of hard registers that are suggested for quantity Q by
+ arithmetic insns. */
-static rtx *qty_scratch_rtx;
+static HARD_REG_SET *qty_phys_sugg;
-/* Element Q is nonzero if this quantity has been used in a SUBREG
- that changes its size. */
+/* Element Q is the number of suggested registers in qty_phys_copy_sugg. */
-static char *qty_changes_size;
+static short *qty_phys_num_copy_sugg;
-/* Element Q is the register number of one pseudo register whose
- reg_qty value is Q, or -1 is this quantity is for a SCRATCH. This
- register should be the head of the chain maintained in reg_next_in_qty. */
+/* Element Q is the number of suggested registers in qty_phys_sugg. */
-static int *qty_first_reg;
+static short *qty_phys_num_sugg;
/* If (REG N) has been assigned a quantity number, is a register number
of another register assigned the same quantity number, or -1 for the
- end of the chain. qty_first_reg point to the head of this chain. */
+ end of the chain. qty->first_reg point to the head of this chain. */
static int *reg_next_in_qty;
static HARD_REG_SET *regs_live_at;
-int *scratch_block;
-rtx *scratch_list;
-int scratch_list_length;
-static int scratch_index;
-
/* Communicate local vars `insn_number' and `insn'
from `block_alloc' to `reg_is_set', `wipe_dead_reg', and `alloc_qty'. */
static int this_insn_number;
static rtx this_insn;
-/* Used to communicate changes made by update_equiv_regs to
- memref_referenced_p. reg_equiv_replacement is set for any REG_EQUIV note
- found or created, so that we can keep track of what memory accesses might
- be created later, e.g. by reload. */
-
-static rtx *reg_equiv_replacement;
-
-static void alloc_qty PROTO((int, enum machine_mode, int, int));
-static void alloc_qty_for_scratch PROTO((rtx, int, rtx, int, int));
-static void validate_equiv_mem_from_store PROTO((rtx, rtx));
-static int validate_equiv_mem PROTO((rtx, rtx, rtx));
-static int contains_replace_regs PROTO((rtx, char *));
-static int memref_referenced_p PROTO((rtx, rtx));
-static int memref_used_between_p PROTO((rtx, rtx, rtx));
-static void optimize_reg_copy_1 PROTO((rtx, rtx, rtx));
-static void optimize_reg_copy_2 PROTO((rtx, rtx, rtx));
-static void update_equiv_regs PROTO((void));
-static void block_alloc PROTO((int));
-static int qty_sugg_compare PROTO((int, int));
-static int qty_sugg_compare_1 PROTO((const GENERIC_PTR, const GENERIC_PTR));
-static int qty_compare PROTO((int, int));
-static int qty_compare_1 PROTO((const GENERIC_PTR, const GENERIC_PTR));
-static int combine_regs PROTO((rtx, rtx, int, int, rtx, int));
-static int reg_meets_class_p PROTO((int, enum reg_class));
-static int reg_classes_overlap_p PROTO((enum reg_class, enum reg_class,
- int));
-static void update_qty_class PROTO((int, int));
-static void reg_is_set PROTO((rtx, rtx));
-static void reg_is_born PROTO((rtx, int));
-static void wipe_dead_reg PROTO((rtx, int));
-static int find_free_reg PROTO((enum reg_class, enum machine_mode,
+struct equivalence
+{
+ /* Set when an attempt should be made to replace a register
+ with the associated src entry. */
+
+ char replace;
+
+ /* Set when a REG_EQUIV note is found or created. Use to
+ keep track of what memory accesses might be created later,
+ e.g. by reload. */
+
+ rtx replacement;
+
+ rtx src;
+
+ /* Loop depth is used to recognize equivalences which appear
+ to be present within the same loop (or in an inner loop). */
+
+ int loop_depth;
+
+ /* The list of each instruction which initializes this register. */
+
+ rtx init_insns;
+};
+
+/* reg_equiv[N] (where N is a pseudo reg number) is the equivalence
+ structure for that register. */
+
+static struct equivalence *reg_equiv;
+
+/* Nonzero if we recorded an equivalence for a LABEL_REF. */
+static int recorded_label_ref;
+
+static void alloc_qty PARAMS ((int, enum machine_mode, int, int));
+static void validate_equiv_mem_from_store PARAMS ((rtx, rtx, void *));
+static int validate_equiv_mem PARAMS ((rtx, rtx, rtx));
+static int equiv_init_varies_p PARAMS ((rtx));
+static int equiv_init_movable_p PARAMS ((rtx, int));
+static int contains_replace_regs PARAMS ((rtx));
+static int memref_referenced_p PARAMS ((rtx, rtx));
+static int memref_used_between_p PARAMS ((rtx, rtx, rtx));
+static void update_equiv_regs PARAMS ((void));
+static void no_equiv PARAMS ((rtx, rtx, void *));
+static void block_alloc PARAMS ((int));
+static int qty_sugg_compare PARAMS ((int, int));
+static int qty_sugg_compare_1 PARAMS ((const PTR, const PTR));
+static int qty_compare PARAMS ((int, int));
+static int qty_compare_1 PARAMS ((const PTR, const PTR));
+static int combine_regs PARAMS ((rtx, rtx, int, int, rtx, int));
+static int reg_meets_class_p PARAMS ((int, enum reg_class));
+static void update_qty_class PARAMS ((int, int));
+static void reg_is_set PARAMS ((rtx, rtx, void *));
+static void reg_is_born PARAMS ((rtx, int));
+static void wipe_dead_reg PARAMS ((rtx, int));
+static int find_free_reg PARAMS ((enum reg_class, enum machine_mode,
int, int, int, int, int));
-static void mark_life PROTO((int, enum machine_mode, int));
-static void post_mark_life PROTO((int, enum machine_mode, int, int, int));
-static int no_conflict_p PROTO((rtx, rtx, rtx));
-static int requires_inout PROTO((char *));
+static void mark_life PARAMS ((int, enum machine_mode, int));
+static void post_mark_life PARAMS ((int, enum machine_mode, int, int, int));
+static int no_conflict_p PARAMS ((rtx, rtx, rtx));
+static int requires_inout PARAMS ((const char *));
\f
/* Allocate a new quantity (new within current basic block)
for register number REGNO which is born at index BIRTH
enum machine_mode mode;
int size, birth;
{
- register int qty = next_qty++;
+ register int qtyno = next_qty++;
- reg_qty[regno] = qty;
+ reg_qty[regno] = qtyno;
reg_offset[regno] = 0;
reg_next_in_qty[regno] = -1;
- qty_first_reg[qty] = regno;
- qty_size[qty] = size;
- qty_mode[qty] = mode;
- qty_birth[qty] = birth;
- qty_n_calls_crossed[qty] = REG_N_CALLS_CROSSED (regno);
- qty_min_class[qty] = reg_preferred_class (regno);
- qty_alternate_class[qty] = reg_alternate_class (regno);
- qty_n_refs[qty] = REG_N_REFS (regno);
- qty_changes_size[qty] = REG_CHANGES_SIZE (regno);
-}
-\f
-/* Similar to `alloc_qty', but allocates a quantity for a SCRATCH rtx
- used as operand N in INSN. We assume here that the SCRATCH is used in
- a CLOBBER. */
-
-static void
-alloc_qty_for_scratch (scratch, n, insn, insn_code_num, insn_number)
- rtx scratch;
- int n;
- rtx insn;
- int insn_code_num, insn_number;
-{
- register int qty;
- enum reg_class class;
- char *p, c;
- int i;
-
-#ifdef REGISTER_CONSTRAINTS
- /* If we haven't yet computed which alternative will be used, do so now.
- Then set P to the constraints for that alternative. */
- if (which_alternative == -1)
- if (! constrain_operands (insn_code_num, 0))
- return;
-
- for (p = insn_operand_constraint[insn_code_num][n], i = 0;
- *p && i < which_alternative; p++)
- if (*p == ',')
- i++;
-
- /* Compute the class required for this SCRATCH. If we don't need a
- register, the class will remain NO_REGS. If we guessed the alternative
- number incorrectly, reload will fix things up for us. */
-
- class = NO_REGS;
- while ((c = *p++) != '\0' && c != ',')
- switch (c)
- {
- case '=': case '+': case '?':
- case '#': case '&': case '!':
- case '*': case '%':
- case '0': case '1': case '2': case '3': case '4':
- case 'm': case '<': case '>': case 'V': case 'o':
- case 'E': case 'F': case 'G': case 'H':
- case 's': case 'i': case 'n':
- case 'I': case 'J': case 'K': case 'L':
- case 'M': case 'N': case 'O': case 'P':
-#ifdef EXTRA_CONSTRAINT
- case 'Q': case 'R': case 'S': case 'T': case 'U':
-#endif
- case 'p':
- /* These don't say anything we care about. */
- break;
-
- case 'X':
- /* We don't need to allocate this SCRATCH. */
- return;
-
- case 'g': case 'r':
- class = reg_class_subunion[(int) class][(int) GENERAL_REGS];
- break;
-
- default:
- class
- = reg_class_subunion[(int) class][(int) REG_CLASS_FROM_LETTER (c)];
- break;
- }
-
- if (class == NO_REGS)
- return;
-
-#else /* REGISTER_CONSTRAINTS */
-
- class = GENERAL_REGS;
-#endif
-
-
- qty = next_qty++;
-
- qty_first_reg[qty] = -1;
- qty_scratch_rtx[qty] = scratch;
- qty_size[qty] = GET_MODE_SIZE (GET_MODE (scratch));
- qty_mode[qty] = GET_MODE (scratch);
- qty_birth[qty] = 2 * insn_number - 1;
- qty_death[qty] = 2 * insn_number + 1;
- qty_n_calls_crossed[qty] = 0;
- qty_min_class[qty] = class;
- qty_alternate_class[qty] = NO_REGS;
- qty_n_refs[qty] = 1;
- qty_changes_size[qty] = 0;
+ qty[qtyno].first_reg = regno;
+ qty[qtyno].size = size;
+ qty[qtyno].mode = mode;
+ qty[qtyno].birth = birth;
+ qty[qtyno].n_calls_crossed = REG_N_CALLS_CROSSED (regno);
+ qty[qtyno].min_class = reg_preferred_class (regno);
+ qty[qtyno].alternate_class = reg_alternate_class (regno);
+ qty[qtyno].n_refs = REG_N_REFS (regno);
+ qty[qtyno].changes_mode = REG_CHANGES_MODE (regno);
}
\f
/* Main entry point of this file. */
-void
+int
local_alloc ()
{
register int b, i;
int max_qty;
+ /* We need to keep track of whether or not we recorded a LABEL_REF so
+ that we know if the jump optimizer needs to be rerun. */
+ recorded_label_ref = 0;
+
/* Leaf functions and non-leaf functions have different needs.
If defined, let the machine say what kind of ordering we
should use. */
update_equiv_regs ();
/* This sets the maximum number of quantities we can have. Quantity
- numbers start at zero and we can have one for each pseudo plus the
- number of SCRATCHes in the largest block, in the worst case. */
- max_qty = (max_regno - FIRST_PSEUDO_REGISTER) + max_scratch;
+ numbers start at zero and we can have one for each pseudo. */
+ max_qty = (max_regno - FIRST_PSEUDO_REGISTER);
/* Allocate vectors of temporary data.
See the declarations of these variables, above,
for what they mean. */
- /* There can be up to MAX_SCRATCH * N_BASIC_BLOCKS SCRATCHes to allocate.
- Instead of allocating this much memory from now until the end of
- reload, only allocate space for MAX_QTY SCRATCHes. If there are more
- reload will allocate them. */
+ qty = (struct qty *) xmalloc (max_qty * sizeof (struct qty));
+ qty_phys_copy_sugg
+ = (HARD_REG_SET *) xmalloc (max_qty * sizeof (HARD_REG_SET));
+ qty_phys_num_copy_sugg = (short *) xmalloc (max_qty * sizeof (short));
+ qty_phys_sugg = (HARD_REG_SET *) xmalloc (max_qty * sizeof (HARD_REG_SET));
+ qty_phys_num_sugg = (short *) xmalloc (max_qty * sizeof (short));
- scratch_list_length = max_qty;
- scratch_list = (rtx *) xmalloc (scratch_list_length * sizeof (rtx));
- bzero ((char *) scratch_list, scratch_list_length * sizeof (rtx));
- scratch_block = (int *) xmalloc (scratch_list_length * sizeof (int));
- bzero ((char *) scratch_block, scratch_list_length * sizeof (int));
- scratch_index = 0;
+ reg_qty = (int *) xmalloc (max_regno * sizeof (int));
+ reg_offset = (char *) xmalloc (max_regno * sizeof (char));
+ reg_next_in_qty = (int *) xmalloc (max_regno * sizeof (int));
- qty_phys_reg = (short *) alloca (max_qty * sizeof (short));
- qty_phys_copy_sugg
- = (HARD_REG_SET *) alloca (max_qty * sizeof (HARD_REG_SET));
- qty_phys_num_copy_sugg = (short *) alloca (max_qty * sizeof (short));
- qty_phys_sugg = (HARD_REG_SET *) alloca (max_qty * sizeof (HARD_REG_SET));
- qty_phys_num_sugg = (short *) alloca (max_qty * sizeof (short));
- qty_birth = (int *) alloca (max_qty * sizeof (int));
- qty_death = (int *) alloca (max_qty * sizeof (int));
- qty_scratch_rtx = (rtx *) alloca (max_qty * sizeof (rtx));
- qty_first_reg = (int *) alloca (max_qty * sizeof (int));
- qty_size = (int *) alloca (max_qty * sizeof (int));
- qty_mode
- = (enum machine_mode *) alloca (max_qty * sizeof (enum machine_mode));
- qty_n_calls_crossed = (int *) alloca (max_qty * sizeof (int));
- qty_min_class
- = (enum reg_class *) alloca (max_qty * sizeof (enum reg_class));
- qty_alternate_class
- = (enum reg_class *) alloca (max_qty * sizeof (enum reg_class));
- qty_n_refs = (int *) alloca (max_qty * sizeof (int));
- qty_changes_size = (char *) alloca (max_qty * sizeof (char));
-
- reg_qty = (int *) alloca (max_regno * sizeof (int));
- reg_offset = (char *) alloca (max_regno * sizeof (char));
- reg_next_in_qty = (int *) alloca (max_regno * sizeof (int));
-
- /* Allocate the reg_renumber array */
+ /* Allocate the reg_renumber array. */
allocate_reg_info (max_regno, FALSE, TRUE);
/* Determine which pseudo-registers can be allocated by local-alloc.
In general, these are the registers used only in a single block and
- which only die once. However, if a register's preferred class has only
- a few entries, don't allocate this register here unless it is preferred
- or nothing since retry_global_alloc won't be able to move it to
- GENERAL_REGS if a reload register of this class is needed.
+ which only die once.
We need not be concerned with which block actually uses the register
since we will never see it outside that block. */
for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
{
- if (REG_BASIC_BLOCK (i) >= 0 && REG_N_DEATHS (i) == 1
- && (reg_alternate_class (i) == NO_REGS
- || ! CLASS_LIKELY_SPILLED_P (reg_preferred_class (i))))
+ if (REG_BASIC_BLOCK (i) >= 0 && REG_N_DEATHS (i) == 1)
reg_qty[i] = -2;
else
reg_qty[i] = -1;
{
for (i = 0; i < next_qty; i++)
{
- qty_scratch_rtx[i] = 0;
CLEAR_HARD_REG_SET (qty_phys_copy_sugg[i]);
qty_phys_num_copy_sugg[i] = 0;
CLEAR_HARD_REG_SET (qty_phys_sugg[i]);
else
{
#define CLEAR(vector) \
- bzero ((char *) (vector), (sizeof (*(vector))) * next_qty);
+ memset ((char *) (vector), 0, (sizeof (*(vector))) * next_qty);
- CLEAR (qty_scratch_rtx);
CLEAR (qty_phys_copy_sugg);
CLEAR (qty_phys_num_copy_sugg);
CLEAR (qty_phys_sugg);
next_qty = 0;
block_alloc (b);
-#ifdef USE_C_ALLOCA
- alloca (0);
-#endif
}
+
+ free (qty);
+ free (qty_phys_copy_sugg);
+ free (qty_phys_num_copy_sugg);
+ free (qty_phys_sugg);
+ free (qty_phys_num_sugg);
+
+ free (reg_qty);
+ free (reg_offset);
+ free (reg_next_in_qty);
+
+ return recorded_label_ref;
}
\f
-/* Depth of loops we are in while in update_equiv_regs. */
-static int loop_depth;
-
/* Used for communication between the following two functions: contains
a MEM that we wish to ensure remains unchanged. */
static rtx equiv_mem;
Called via note_stores. */
static void
-validate_equiv_mem_from_store (dest, set)
+validate_equiv_mem_from_store (dest, set, data)
rtx dest;
- rtx set;
+ rtx set ATTRIBUTE_UNUSED;
+ void *data ATTRIBUTE_UNUSED;
{
if ((GET_CODE (dest) == REG
&& reg_overlap_mentioned_p (dest, equiv_mem))
for (insn = start; insn && ! equiv_mem_modified; insn = NEXT_INSN (insn))
{
- if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ if (! INSN_P (insn))
continue;
if (find_reg_note (insn, REG_DEAD, reg))
&& ! CONST_CALL_P (insn))
return 0;
- note_stores (PATTERN (insn), validate_equiv_mem_from_store);
+ note_stores (PATTERN (insn), validate_equiv_mem_from_store, NULL);
/* If a register mentioned in MEMREF is modified via an
auto-increment, we lose the equivalence. Do the same if one
return 0;
}
-/* TRUE if X uses any registers for which reg_equiv_replace is true. */
+/* Returns zero if X is known to be invariant. */
static int
-contains_replace_regs (x, reg_equiv_replace)
+equiv_init_varies_p (x)
+ rtx x;
+{
+ register RTX_CODE code = GET_CODE (x);
+ register int i;
+ register const char *fmt;
+
+ switch (code)
+ {
+ case MEM:
+ return ! RTX_UNCHANGING_P (x) || equiv_init_varies_p (XEXP (x, 0));
+
+ case QUEUED:
+ return 1;
+
+ case CONST:
+ case CONST_INT:
+ case CONST_DOUBLE:
+ case SYMBOL_REF:
+ case LABEL_REF:
+ return 0;
+
+ case REG:
+ return reg_equiv[REGNO (x)].replace == 0 && rtx_varies_p (x, 0);
+
+ case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 1;
+
+ /* FALLTHROUGH */
+
+ default:
+ break;
+ }
+
+ fmt = GET_RTX_FORMAT (code);
+ for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+ if (fmt[i] == 'e')
+ {
+ if (equiv_init_varies_p (XEXP (x, i)))
+ return 1;
+ }
+ else if (fmt[i] == 'E')
+ {
+ int j;
+ for (j = 0; j < XVECLEN (x, i); j++)
+ if (equiv_init_varies_p (XVECEXP (x, i, j)))
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Returns non-zero if X (used to initialize register REGNO) is movable.
+ X is only movable if the registers it uses have equivalent initializations
+ which appear to be within the same loop (or in an inner loop) and movable
+ or if they are not candidates for local_alloc and don't vary. */
+
+static int
+equiv_init_movable_p (x, regno)
+ rtx x;
+ int regno;
+{
+ int i, j;
+ const char *fmt;
+ enum rtx_code code = GET_CODE (x);
+
+ switch (code)
+ {
+ case SET:
+ return equiv_init_movable_p (SET_SRC (x), regno);
+
+ case CC0:
+ case CLOBBER:
+ return 0;
+
+ case PRE_INC:
+ case PRE_DEC:
+ case POST_INC:
+ case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
+ return 0;
+
+ case REG:
+ return (reg_equiv[REGNO (x)].loop_depth >= reg_equiv[regno].loop_depth
+ && reg_equiv[REGNO (x)].replace)
+ || (REG_BASIC_BLOCK (REGNO (x)) < 0 && ! rtx_varies_p (x, 0));
+
+ case UNSPEC_VOLATILE:
+ return 0;
+
+ case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 0;
+
+ /* FALLTHROUGH */
+
+ default:
+ break;
+ }
+
+ fmt = GET_RTX_FORMAT (code);
+ for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+ switch (fmt[i])
+ {
+ case 'e':
+ if (! equiv_init_movable_p (XEXP (x, i), regno))
+ return 0;
+ break;
+ case 'E':
+ for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+ if (! equiv_init_movable_p (XVECEXP (x, i, j), regno))
+ return 0;
+ break;
+ }
+
+ return 1;
+}
+
+/* TRUE if X uses any registers for which reg_equiv[REGNO].replace is true. */
+
+static int
+contains_replace_regs (x)
rtx x;
- char *reg_equiv_replace;
{
int i, j;
- char *fmt;
+ const char *fmt;
enum rtx_code code = GET_CODE (x);
switch (code)
return 0;
case REG:
- return reg_equiv_replace[REGNO (x)];
+ return reg_equiv[REGNO (x)].replace;
+
+ default:
+ break;
}
fmt = GET_RTX_FORMAT (code);
switch (fmt[i])
{
case 'e':
- if (contains_replace_regs (XEXP (x, i), reg_equiv_replace))
+ if (contains_replace_regs (XEXP (x, i)))
return 1;
break;
case 'E':
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
- if (contains_replace_regs (XVECEXP (x, i, j), reg_equiv_replace))
+ if (contains_replace_regs (XVECEXP (x, i, j)))
return 1;
break;
}
rtx memref;
{
int i, j;
- char *fmt;
+ const char *fmt;
enum rtx_code code = GET_CODE (x);
switch (code)
return 0;
case REG:
- return (reg_equiv_replacement[REGNO (x)]
+ return (reg_equiv[REGNO (x)].replacement
&& memref_referenced_p (memref,
- reg_equiv_replacement[REGNO (x)]));
+ reg_equiv[REGNO (x)].replacement));
case MEM:
if (true_dependence (memref, VOIDmode, x, rtx_varies_p))
return 1;
return memref_referenced_p (memref, SET_SRC (x));
+
+ default:
+ break;
}
fmt = GET_RTX_FORMAT (code);
for (insn = NEXT_INSN (start); insn != NEXT_INSN (end);
insn = NEXT_INSN (insn))
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
- && memref_referenced_p (memref, PATTERN (insn)))
+ if (INSN_P (insn) && memref_referenced_p (memref, PATTERN (insn)))
return 1;
return 0;
}
\f
-/* INSN is a copy from SRC to DEST, both registers, and SRC does not die
- in INSN.
-
- Search forward to see if SRC dies before either it or DEST is modified,
- but don't scan past the end of a basic block. If so, we can replace SRC
- with DEST and let SRC die in INSN.
-
- This will reduce the number of registers live in that range and may enable
- DEST to be tied to SRC, thus often saving one register in addition to a
- register-register copy. */
-
-static void
-optimize_reg_copy_1 (insn, dest, src)
- rtx insn;
- rtx dest;
- rtx src;
+/* Return nonzero if the rtx X is invariant over the current function. */
+int
+function_invariant_p (x)
+ rtx x;
{
- rtx p, q;
- rtx note;
- rtx dest_death = 0;
- int sregno = REGNO (src);
- int dregno = REGNO (dest);
-
- if (sregno == dregno
-#ifdef SMALL_REGISTER_CLASSES
- /* We don't want to mess with hard regs if register classes are small. */
- || (SMALL_REGISTER_CLASSES
- && (sregno < FIRST_PSEUDO_REGISTER
- || dregno < FIRST_PSEUDO_REGISTER))
-#endif
- /* We don't see all updates to SP if they are in an auto-inc memory
- reference, so we must disallow this optimization on them. */
- || sregno == STACK_POINTER_REGNUM || dregno == STACK_POINTER_REGNUM)
- return;
-
- for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
- {
- if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN
- || (GET_CODE (p) == NOTE
- && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG
- || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END)))
- break;
-
- if (GET_RTX_CLASS (GET_CODE (p)) != 'i')
- continue;
-
- if (reg_set_p (src, p) || reg_set_p (dest, p)
- /* Don't change a USE of a register. */
- || (GET_CODE (PATTERN (p)) == USE
- && reg_overlap_mentioned_p (src, XEXP (PATTERN (p), 0))))
- break;
-
- /* See if all of SRC dies in P. This test is slightly more
- conservative than it needs to be. */
- if ((note = find_regno_note (p, REG_DEAD, sregno)) != 0
- && GET_MODE (XEXP (note, 0)) == GET_MODE (src))
- {
- int failed = 0;
- int length = 0;
- int d_length = 0;
- int n_calls = 0;
- int d_n_calls = 0;
-
- /* We can do the optimization. Scan forward from INSN again,
- replacing regs as we go. Set FAILED if a replacement can't
- be done. In that case, we can't move the death note for SRC.
- This should be rare. */
-
- /* Set to stop at next insn. */
- for (q = next_real_insn (insn);
- q != next_real_insn (p);
- q = next_real_insn (q))
- {
- if (reg_overlap_mentioned_p (src, PATTERN (q)))
- {
- /* If SRC is a hard register, we might miss some
- overlapping registers with validate_replace_rtx,
- so we would have to undo it. We can't if DEST is
- present in the insn, so fail in that combination
- of cases. */
- if (sregno < FIRST_PSEUDO_REGISTER
- && reg_mentioned_p (dest, PATTERN (q)))
- failed = 1;
-
- /* Replace all uses and make sure that the register
- isn't still present. */
- else if (validate_replace_rtx (src, dest, q)
- && (sregno >= FIRST_PSEUDO_REGISTER
- || ! reg_overlap_mentioned_p (src,
- PATTERN (q))))
- {
- /* We assume that a register is used exactly once per
- insn in the updates below. If this is not correct,
- no great harm is done. */
- if (sregno >= FIRST_PSEUDO_REGISTER)
- REG_N_REFS (sregno) -= loop_depth;
- if (dregno >= FIRST_PSEUDO_REGISTER)
- REG_N_REFS (dregno) += loop_depth;
- }
- else
- {
- validate_replace_rtx (dest, src, q);
- failed = 1;
- }
- }
-
- /* Count the insns and CALL_INSNs passed. If we passed the
- death note of DEST, show increased live length. */
- length++;
- if (dest_death)
- d_length++;
-
- /* If the insn in which SRC dies is a CALL_INSN, don't count it
- as a call that has been crossed. Otherwise, count it. */
- if (q != p && GET_CODE (q) == CALL_INSN)
- {
- n_calls++;
- if (dest_death)
- d_n_calls++;
- }
-
- /* If DEST dies here, remove the death note and save it for
- later. Make sure ALL of DEST dies here; again, this is
- overly conservative. */
- if (dest_death == 0
- && (dest_death = find_regno_note (q, REG_DEAD, dregno)) != 0
- && GET_MODE (XEXP (dest_death, 0)) == GET_MODE (dest))
- remove_note (q, dest_death);
- }
-
- if (! failed)
- {
- if (sregno >= FIRST_PSEUDO_REGISTER)
- {
- if (REG_LIVE_LENGTH (sregno) >= 0)
- {
- REG_LIVE_LENGTH (sregno) -= length;
- /* reg_live_length is only an approximation after
- combine if sched is not run, so make sure that we
- still have a reasonable value. */
- if (REG_LIVE_LENGTH (sregno) < 2)
- REG_LIVE_LENGTH (sregno) = 2;
- }
-
- REG_N_CALLS_CROSSED (sregno) -= n_calls;
- }
-
- if (dregno >= FIRST_PSEUDO_REGISTER)
- {
- if (REG_LIVE_LENGTH (dregno) >= 0)
- REG_LIVE_LENGTH (dregno) += d_length;
-
- REG_N_CALLS_CROSSED (dregno) += d_n_calls;
- }
-
- /* Move death note of SRC from P to INSN. */
- remove_note (p, note);
- XEXP (note, 1) = REG_NOTES (insn);
- REG_NOTES (insn) = note;
- }
-
- /* Put death note of DEST on P if we saw it die. */
- if (dest_death)
- {
- XEXP (dest_death, 1) = REG_NOTES (p);
- REG_NOTES (p) = dest_death;
- }
-
- return;
- }
-
- /* If SRC is a hard register which is set or killed in some other
- way, we can't do this optimization. */
- else if (sregno < FIRST_PSEUDO_REGISTER
- && dead_or_set_p (p, src))
- break;
- }
+ if (CONSTANT_P (x))
+ return 1;
+ if (x == frame_pointer_rtx || x == arg_pointer_rtx)
+ return 1;
+ if (GET_CODE (x) == PLUS
+ && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx)
+ && CONSTANT_P (XEXP (x, 1)))
+ return 1;
+ return 0;
}
-\f
-/* INSN is a copy of SRC to DEST, in which SRC dies. See if we now have
- a sequence of insns that modify DEST followed by an insn that sets
- SRC to DEST in which DEST dies, with no prior modification of DEST.
- (There is no need to check if the insns in between actually modify
- DEST. We should not have cases where DEST is not modified, but
- the optimization is safe if no such modification is detected.)
- In that case, we can replace all uses of DEST, starting with INSN and
- ending with the set of SRC to DEST, with SRC. We do not do this
- optimization if a CALL_INSN is crossed unless SRC already crosses a
- call or if DEST dies before the copy back to SRC.
-
- It is assumed that DEST and SRC are pseudos; it is too complicated to do
- this for hard registers since the substitutions we may make might fail. */
-
-static void
-optimize_reg_copy_2 (insn, dest, src)
- rtx insn;
- rtx dest;
- rtx src;
-{
- rtx p, q;
- rtx set;
- int sregno = REGNO (src);
- int dregno = REGNO (dest);
-
- for (p = NEXT_INSN (insn); p; p = NEXT_INSN (p))
- {
- if (GET_CODE (p) == CODE_LABEL || GET_CODE (p) == JUMP_INSN
- || (GET_CODE (p) == NOTE
- && (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG
- || NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END)))
- break;
-
- if (GET_RTX_CLASS (GET_CODE (p)) != 'i')
- continue;
-
- set = single_set (p);
- if (set && SET_SRC (set) == dest && SET_DEST (set) == src
- && find_reg_note (p, REG_DEAD, dest))
- {
- /* We can do the optimization. Scan forward from INSN again,
- replacing regs as we go. */
-
- /* Set to stop at next insn. */
- for (q = insn; q != NEXT_INSN (p); q = NEXT_INSN (q))
- if (GET_RTX_CLASS (GET_CODE (q)) == 'i')
- {
- if (reg_mentioned_p (dest, PATTERN (q)))
- {
- PATTERN (q) = replace_rtx (PATTERN (q), dest, src);
-
- /* We assume that a register is used exactly once per
- insn in the updates below. If this is not correct,
- no great harm is done. */
- REG_N_REFS (dregno) -= loop_depth;
- REG_N_REFS (sregno) += loop_depth;
- }
-
-
- if (GET_CODE (q) == CALL_INSN)
- {
- REG_N_CALLS_CROSSED (dregno)--;
- REG_N_CALLS_CROSSED (sregno)++;
- }
- }
-
- remove_note (p, find_reg_note (p, REG_DEAD, dest));
- REG_N_DEATHS (dregno)--;
- remove_note (insn, find_reg_note (insn, REG_DEAD, src));
- REG_N_DEATHS (sregno)--;
- return;
- }
- if (reg_set_p (src, p)
- || find_reg_note (p, REG_DEAD, dest)
- || (GET_CODE (p) == CALL_INSN && REG_N_CALLS_CROSSED (sregno) == 0))
- break;
- }
-}
-\f
/* Find registers that are equivalent to a single value throughout the
compilation (either because they can be referenced in memory or are set once
from a single constant). Lower their priority for a register.
static void
update_equiv_regs ()
{
- rtx *reg_equiv_init_insn = (rtx *) alloca (max_regno * sizeof (rtx *));
- /* Set when an attempt should be made to replace a register with the
- associated reg_equiv_replacement entry at the end of this function. */
- char *reg_equiv_replace
- = (char *) alloca (max_regno * sizeof *reg_equiv_replace);
rtx insn;
- int block, depth;
-
- reg_equiv_replacement = (rtx *) alloca (max_regno * sizeof (rtx *));
+ int block;
+ int loop_depth;
+ regset_head cleared_regs;
+ int clear_regnos = 0;
- bzero ((char *) reg_equiv_init_insn, max_regno * sizeof (rtx *));
- bzero ((char *) reg_equiv_replacement, max_regno * sizeof (rtx *));
- bzero ((char *) reg_equiv_replace, max_regno * sizeof *reg_equiv_replace);
+ reg_equiv = (struct equivalence *) xcalloc (max_regno, sizeof *reg_equiv);
+ INIT_REG_SET (&cleared_regs);
init_alias_analysis ();
- loop_depth = 1;
-
/* Scan the insns and find which registers have equivalences. Do this
in a separate scan of the insns because (due to -fcse-follow-jumps)
a register can be set below its use. */
+ loop_depth = 0;
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
{
rtx note;
- rtx set = single_set (insn);
+ rtx set;
rtx dest, src;
int regno;
if (GET_CODE (insn) == NOTE)
{
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
- loop_depth++;
+ ++loop_depth;
else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
- loop_depth--;
+ {
+ if (! loop_depth)
+ abort ();
+ --loop_depth;
+ }
}
- /* If this insn contains more (or less) than a single SET, ignore it. */
- if (set == 0)
+ if (! INSN_P (insn))
continue;
+ for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_INC)
+ no_equiv (XEXP (note, 0), note, NULL);
+
+ set = single_set (insn);
+
+ /* If this insn contains more (or less) than a single SET,
+ only mark all destinations as having no known equivalence. */
+ if (set == 0)
+ {
+ note_stores (PATTERN (insn), no_equiv, NULL);
+ continue;
+ }
+ else if (GET_CODE (PATTERN (insn)) == PARALLEL)
+ {
+ int i;
+
+ for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
+ {
+ rtx part = XVECEXP (PATTERN (insn), 0, i);
+ if (part != set)
+ note_stores (part, no_equiv, NULL);
+ }
+ }
+
dest = SET_DEST (set);
src = SET_SRC (set);
Don't add a REG_EQUIV note if the insn already has one. The existing
REG_EQUIV is likely more useful than the one we are adding.
- If one of the regs in the address is marked as reg_equiv_replace,
- then we can't add this REG_EQUIV note. The reg_equiv_replace
+ If one of the regs in the address has reg_equiv[REGNO].replace set,
+ then we can't add this REG_EQUIV note. The reg_equiv[REGNO].replace
optimization may move the set of this register immediately before
- insn, which puts it after reg_equiv_init_insn[regno], and hence
+ insn, which puts it after reg_equiv[REGNO].init_insns, and hence
the mention in the REG_EQUIV note would be to an uninitialized
pseudo. */
-
- if (GET_CODE (dest) == MEM && GET_CODE (SET_SRC (set)) == REG
- && (regno = REGNO (SET_SRC (set))) >= FIRST_PSEUDO_REGISTER
+ /* ????? This test isn't good enough; we might see a MEM with a use of
+ a pseudo register before we see its setting insn that will cause
+ reg_equiv[].replace for that pseudo to be set.
+ Equivalences to MEMs should be made in another pass, after the
+ reg_equiv[].replace information has been gathered. */
+
+ if (GET_CODE (dest) == MEM && GET_CODE (src) == REG
+ && (regno = REGNO (src)) >= FIRST_PSEUDO_REGISTER
&& REG_BASIC_BLOCK (regno) >= 0
- && reg_equiv_init_insn[regno] != 0
- && ! find_reg_note (insn, REG_EQUIV, NULL_RTX)
- && ! contains_replace_regs (XEXP (dest, 0), reg_equiv_replace)
- && validate_equiv_mem (reg_equiv_init_insn[regno], SET_SRC (set),
- dest)
- && ! memref_used_between_p (SET_DEST (set),
- reg_equiv_init_insn[regno], insn))
- REG_NOTES (reg_equiv_init_insn[regno])
- = gen_rtx (EXPR_LIST, REG_EQUIV, dest,
- REG_NOTES (reg_equiv_init_insn[regno]));
-
- /* If this is a register-register copy where SRC is not dead, see if we
- can optimize it. */
- if (flag_expensive_optimizations && GET_CODE (dest) == REG
- && GET_CODE (SET_SRC (set)) == REG
- && ! find_reg_note (insn, REG_DEAD, SET_SRC (set)))
- optimize_reg_copy_1 (insn, dest, SET_SRC (set));
-
- /* Similarly for a pseudo-pseudo copy when SRC is dead. */
- else if (flag_expensive_optimizations && GET_CODE (dest) == REG
- && REGNO (dest) >= FIRST_PSEUDO_REGISTER
- && GET_CODE (SET_SRC (set)) == REG
- && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER
- && find_reg_note (insn, REG_DEAD, SET_SRC (set)))
- optimize_reg_copy_2 (insn, dest, SET_SRC (set));
-
- /* Otherwise, we only handle the case of a pseudo register being set
- once and only if neither the source nor the destination are
- in a register class that's likely to be spilled. */
+ && REG_N_SETS (regno) == 1
+ && reg_equiv[regno].init_insns != 0
+ && reg_equiv[regno].init_insns != const0_rtx
+ && ! find_reg_note (XEXP (reg_equiv[regno].init_insns, 0),
+ REG_EQUIV, NULL_RTX)
+ && ! contains_replace_regs (XEXP (dest, 0)))
+ {
+ rtx init_insn = XEXP (reg_equiv[regno].init_insns, 0);
+ if (validate_equiv_mem (init_insn, src, dest)
+ && ! memref_used_between_p (dest, init_insn, insn))
+ REG_NOTES (init_insn)
+ = gen_rtx_EXPR_LIST (REG_EQUIV, dest, REG_NOTES (init_insn));
+ }
+
+ /* We only handle the case of a pseudo register being set
+ once, or always to the same value. */
+ /* ??? The mn10200 port breaks if we add equivalences for
+ values that need an ADDRESS_REGS register and set them equivalent
+ to a MEM of a pseudo. The actual problem is in the over-conservative
+ handling of INPADDR_ADDRESS / INPUT_ADDRESS / INPUT triples in
+ calculate_needs, but we traditionally work around this problem
+ here by rejecting equivalences when the destination is in a register
+ that's likely spilled. This is fragile, of course, since the
+ preferred class of a pseudo depends on all instructions that set
+ or use it. */
+
if (GET_CODE (dest) != REG
|| (regno = REGNO (dest)) < FIRST_PSEUDO_REGISTER
- || REG_N_SETS (regno) != 1
- || CLASS_LIKELY_SPILLED_P (reg_preferred_class (REGNO (dest)))
- || (GET_CODE (src) == REG
- && REGNO (src) >= FIRST_PSEUDO_REGISTER
- && CLASS_LIKELY_SPILLED_P (reg_preferred_class (REGNO (src)))))
- continue;
+ || reg_equiv[regno].init_insns == const0_rtx
+ || (CLASS_LIKELY_SPILLED_P (reg_preferred_class (regno))
+ && GET_CODE (src) == MEM))
+ {
+ /* This might be seting a SUBREG of a pseudo, a pseudo that is
+ also set somewhere else to a constant. */
+ note_stores (set, no_equiv, NULL);
+ continue;
+ }
note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
-#ifdef DONT_RECORD_EQUIVALENCE
- /* Allow the target to reject promotions of some REG_EQUAL notes to
- REG_EQUIV notes.
-
- In some cases this can improve register allocation if the existence
- of the REG_EQUIV note is likely to increase the lifetime of a register
- that is likely to be spilled.
-
- It may also be necessary if the target can't handle certain constant
- expressions appearing randomly in insns, but for whatever reason
- those expressions must be considered legitimate constant expressions
- to prevent them from being forced into memory. */
- if (note && DONT_RECORD_EQUIVALENCE (note))
- note = NULL;
-#endif
-
+ /* cse sometimes generates function invariants, but doesn't put a
+ REG_EQUAL note on the insn. Since this note would be redundant,
+ there's no point creating it earlier than here. */
+ if (! note && ! rtx_varies_p (src, 0))
+ REG_NOTES (insn)
+ = note = gen_rtx_EXPR_LIST (REG_EQUAL, src, REG_NOTES (insn));
+
+ /* Don't bother considering a REG_EQUAL note containing an EXPR_LIST
+ since it represents a function call */
+ if (note && GET_CODE (XEXP (note, 0)) == EXPR_LIST)
+ note = NULL_RTX;
+
+ if (REG_N_SETS (regno) != 1
+ && (! note
+ || rtx_varies_p (XEXP (note, 0), 0)
+ || (reg_equiv[regno].replacement
+ && ! rtx_equal_p (XEXP (note, 0),
+ reg_equiv[regno].replacement))))
+ {
+ no_equiv (dest, set, NULL);
+ continue;
+ }
/* Record this insn as initializing this register. */
- reg_equiv_init_insn[regno] = insn;
+ reg_equiv[regno].init_insns
+ = gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv[regno].init_insns);
/* If this register is known to be equal to a constant, record that
it is always equivalent to the constant. */
- if (note && CONSTANT_P (XEXP (note, 0)))
+ if (note && ! rtx_varies_p (XEXP (note, 0), 0))
PUT_MODE (note, (enum machine_mode) REG_EQUIV);
/* If this insn introduces a "constant" register, decrease the priority
a register used only in one basic block from a MEM. If so, and the
MEM remains unchanged for the life of the register, add a REG_EQUIV
note. */
-
+
note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
if (note == 0 && REG_BASIC_BLOCK (regno) >= 0
&& GET_CODE (SET_SRC (set)) == MEM
&& validate_equiv_mem (insn, dest, SET_SRC (set)))
- REG_NOTES (insn) = note = gen_rtx (EXPR_LIST, REG_EQUIV, SET_SRC (set),
- REG_NOTES (insn));
+ REG_NOTES (insn) = note = gen_rtx_EXPR_LIST (REG_EQUIV, SET_SRC (set),
+ REG_NOTES (insn));
if (note)
{
int regno = REGNO (dest);
- reg_equiv_replacement[regno] = XEXP (note, 0);
+ /* Record whether or not we created a REG_EQUIV note for a LABEL_REF.
+ We might end up substituting the LABEL_REF for uses of the
+ pseudo here or later. That kind of transformation may turn an
+ indirect jump into a direct jump, in which case we must rerun the
+ jump optimizer to ensure that the JUMP_LABEL fields are valid. */
+ if (GET_CODE (XEXP (note, 0)) == LABEL_REF
+ || (GET_CODE (XEXP (note, 0)) == CONST
+ && GET_CODE (XEXP (XEXP (note, 0), 0)) == PLUS
+ && (GET_CODE (XEXP (XEXP (XEXP (note, 0), 0), 0))
+ == LABEL_REF)))
+ recorded_label_ref = 1;
+
+ reg_equiv[regno].replacement = XEXP (note, 0);
+ reg_equiv[regno].src = src;
+ reg_equiv[regno].loop_depth = loop_depth;
/* Don't mess with things live during setjmp. */
if (REG_LIVE_LENGTH (regno) >= 0)
/* If the register is referenced exactly twice, meaning it is
set once and used once, indicate that the reference may be
- replaced by the equivalence we computed above. If the
- register is only used in one basic block, this can't succeed
- or combine would have done it.
+ replaced by the equivalence we computed above. Do this
+ even if the register is only used in one block so that
+ dependencies can be handled where the last register is
+ used in a different block (i.e. HIGH / LO_SUM sequences)
+ and to reduce the number of registers alive across calls.
It would be nice to use "loop_depth * 2" in the compare
below. Unfortunately, LOOP_DEPTH need not be constant within
memory and then used exactly once, not in a loop. */
if (REG_N_REFS (regno) == 2
- && REG_BASIC_BLOCK (regno) < 0
- && rtx_equal_p (XEXP (note, 0), SET_SRC (set)))
- reg_equiv_replace[regno] = 1;
+ && (rtx_equal_p (XEXP (note, 0), src)
+ || ! equiv_init_varies_p (src))
+ && GET_CODE (insn) == INSN
+ && equiv_init_movable_p (PATTERN (insn), regno))
+ reg_equiv[regno].replace = 1;
}
}
}
registers only used that once. If so, see if we can replace the
reference with the equivalent from. If we can, delete the
initializing reference and this register will go away. If we
- can't replace the reference, and the instruction is not in a
- loop, then move the register initialization just before the use,
- so that they are in the same basic block. */
- block = -1;
- depth = 0;
- for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
+ can't replace the reference, and the initialzing reference is
+ within the same loop (or in an inner loop), then move the register
+ initialization just before the use, so that they are in the same
+ basic block.
+
+ Skip this optimization if loop_depth isn't initially zero since
+ that indicates a mismatch between loop begin and loop end notes
+ (i.e. gcc.dg/noncompile/920721-2.c). */
+ block = n_basic_blocks - 1;
+ for (insn = (loop_depth == 0) ? get_last_insn () : NULL_RTX;
+ insn; insn = PREV_INSN (insn))
{
rtx link;
- /* Keep track of which basic block we are in. */
- if (block + 1 < n_basic_blocks
- && basic_block_head[block + 1] == insn)
- ++block;
-
- if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ if (! INSN_P (insn))
{
if (GET_CODE (insn) == NOTE)
{
- if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
- ++depth;
- else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
+ if (NOTE_INSN_BASIC_BLOCK_P (insn))
+ block = NOTE_BASIC_BLOCK (insn)->index - 1;
+ else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
{
- --depth;
- if (depth < 0)
+ if (! loop_depth)
abort ();
+ --loop_depth;
}
+ else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
+ ++loop_depth;
}
continue;
int regno = REGNO (XEXP (link, 0));
rtx equiv_insn;
- if (! reg_equiv_replace[regno])
+ if (! reg_equiv[regno].replace
+ || reg_equiv[regno].loop_depth < loop_depth)
continue;
- equiv_insn = reg_equiv_init_insn[regno];
-
- if (validate_replace_rtx (regno_reg_rtx[regno],
- reg_equiv_replacement[regno], insn))
+ /* reg_equiv[REGNO].replace gets set only when
+ REG_N_REFS[REGNO] is 2, i.e. the register is set
+ once and used once. (If it were only set, but not used,
+ flow would have deleted the setting insns.) Hence
+ there can only be one insn in reg_equiv[REGNO].init_insns. */
+ if (reg_equiv[regno].init_insns == NULL_RTX
+ || XEXP (reg_equiv[regno].init_insns, 1) != NULL_RTX)
+ abort ();
+ equiv_insn = XEXP (reg_equiv[regno].init_insns, 0);
+
+ if (asm_noperands (PATTERN (equiv_insn)) < 0
+ && validate_replace_rtx (regno_reg_rtx[regno],
+ reg_equiv[regno].src, insn))
{
+ rtx equiv_link;
+ rtx last_link;
+ rtx note;
+
+ /* Find the last note. */
+ for (last_link = link; XEXP (last_link, 1);
+ last_link = XEXP (last_link, 1))
+ ;
+
+ /* Append the REG_DEAD notes from equiv_insn. */
+ equiv_link = REG_NOTES (equiv_insn);
+ while (equiv_link)
+ {
+ note = equiv_link;
+ equiv_link = XEXP (equiv_link, 1);
+ if (REG_NOTE_KIND (note) == REG_DEAD)
+ {
+ remove_note (equiv_insn, note);
+ XEXP (last_link, 1) = note;
+ XEXP (note, 1) = NULL_RTX;
+ last_link = note;
+ }
+ }
+
remove_death (regno, insn);
REG_N_REFS (regno) = 0;
PUT_CODE (equiv_insn, NOTE);
NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (equiv_insn) = 0;
+
+ reg_equiv[regno].init_insns
+ = XEXP (reg_equiv[regno].init_insns, 1);
}
- /* If we aren't in a loop, and there are no calls in
- INSN or in the initialization of the register, then
- move the initialization of the register to just
- before INSN. Update the flow information. */
- else if (depth == 0
- && GET_CODE (equiv_insn) == INSN
- && GET_CODE (insn) == INSN
- && REG_BASIC_BLOCK (regno) < 0)
+ /* Move the initialization of the register to just before
+ INSN. Update the flow information. */
+ else if (PREV_INSN (insn) != equiv_insn)
{
- int l;
+ rtx new_insn;
- emit_insn_before (copy_rtx (PATTERN (equiv_insn)), insn);
+ new_insn = emit_insn_before (PATTERN (equiv_insn), insn);
REG_NOTES (PREV_INSN (insn)) = REG_NOTES (equiv_insn);
+ REG_NOTES (equiv_insn) = 0;
PUT_CODE (equiv_insn, NOTE);
NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (equiv_insn) = 0;
- REG_NOTES (equiv_insn) = 0;
- if (block < 0)
- REG_BASIC_BLOCK (regno) = 0;
- else
- REG_BASIC_BLOCK (regno) = block;
+ XEXP (reg_equiv[regno].init_insns, 0) = new_insn;
+
+ REG_BASIC_BLOCK (regno) = block >= 0 ? block : 0;
REG_N_CALLS_CROSSED (regno) = 0;
REG_LIVE_LENGTH (regno) = 2;
- if (block >= 0 && insn == basic_block_head[block])
- basic_block_head[block] = PREV_INSN (insn);
+ if (block >= 0 && insn == BLOCK_HEAD (block))
+ BLOCK_HEAD (block) = PREV_INSN (insn);
- for (l = 0; l < n_basic_blocks; l++)
- CLEAR_REGNO_REG_SET (basic_block_live_at_start[l], regno);
+ /* Remember to clear REGNO from all basic block's live
+ info. */
+ SET_REGNO_REG_SET (&cleared_regs, regno);
+ clear_regnos++;
}
}
}
}
+
+ /* Clear all dead REGNOs from all basic block's live info. */
+ if (clear_regnos)
+ {
+ int j, l;
+ if (clear_regnos > 8)
+ {
+ for (l = 0; l < n_basic_blocks; l++)
+ {
+ AND_COMPL_REG_SET (BASIC_BLOCK (l)->global_live_at_start,
+ &cleared_regs);
+ AND_COMPL_REG_SET (BASIC_BLOCK (l)->global_live_at_end,
+ &cleared_regs);
+ }
+ }
+ else
+ EXECUTE_IF_SET_IN_REG_SET (&cleared_regs, 0, j,
+ {
+ for (l = 0; l < n_basic_blocks; l++)
+ {
+ CLEAR_REGNO_REG_SET (BASIC_BLOCK (l)->global_live_at_start, j);
+ CLEAR_REGNO_REG_SET (BASIC_BLOCK (l)->global_live_at_end, j);
+ }
+ });
+ }
+
+ /* Clean up. */
+ end_alias_analysis ();
+ CLEAR_REG_SET (&cleared_regs);
+ free (reg_equiv);
+}
+
+/* Mark REG as having no known equivalence.
+ Some instructions might have been proceessed before and furnished
+ with REG_EQUIV notes for this register; these notes will have to be
+ removed.
+ STORE is the piece of RTL that does the non-constant / conflicting
+ assignment - a SET, CLOBBER or REG_INC note. It is currently not used,
+ but needs to be there because this function is called from note_stores. */
+static void
+no_equiv (reg, store, data)
+ rtx reg, store ATTRIBUTE_UNUSED;
+ void *data ATTRIBUTE_UNUSED;
+{
+ int regno;
+ rtx list;
+
+ if (GET_CODE (reg) != REG)
+ return;
+ regno = REGNO (reg);
+ list = reg_equiv[regno].init_insns;
+ if (list == const0_rtx)
+ return;
+ for (; list; list = XEXP (list, 1))
+ {
+ rtx insn = XEXP (list, 0);
+ remove_note (insn, find_reg_note (insn, REG_EQUIV, NULL_RTX));
+ }
+ reg_equiv[regno].init_insns = const0_rtx;
+ reg_equiv[regno].replacement = NULL_RTX;
}
\f
/* Allocate hard regs to the pseudo regs used only within block number B.
int max_uid = get_max_uid ();
int *qty_order;
int no_conflict_combined_regno = -1;
- /* Counter to prevent allocating more SCRATCHes than can be stored
- in SCRATCH_LIST. */
- int scratches_allocated = scratch_index;
/* Count the instructions in the basic block. */
- insn = basic_block_end[b];
+ insn = BLOCK_END (b);
while (1)
{
if (GET_CODE (insn) != NOTE)
if (++insn_count > max_uid)
abort ();
- if (insn == basic_block_head[b])
+ if (insn == BLOCK_HEAD (b))
break;
insn = PREV_INSN (insn);
}
/* +2 to leave room for a post_mark_life at the last insn and for
the birth of a CLOBBER in the first insn. */
- regs_live_at = (HARD_REG_SET *) alloca ((2 * insn_count + 2)
- * sizeof (HARD_REG_SET));
- bzero ((char *) regs_live_at, (2 * insn_count + 2) * sizeof (HARD_REG_SET));
+ regs_live_at = (HARD_REG_SET *) xcalloc ((2 * insn_count + 2),
+ sizeof (HARD_REG_SET));
/* Initialize table of hardware registers currently live. */
- REG_SET_TO_HARD_REG_SET (regs_live, basic_block_live_at_start[b]);
+ REG_SET_TO_HARD_REG_SET (regs_live, BASIC_BLOCK (b)->global_live_at_start);
/* This loop scans the instructions of the basic block
and assigns quantities to registers.
It computes which registers to tie. */
- insn = basic_block_head[b];
+ insn = BLOCK_HEAD (b);
while (1)
{
- register rtx body = PATTERN (insn);
-
if (GET_CODE (insn) != NOTE)
insn_number++;
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
+ if (INSN_P (insn))
{
register rtx link, set;
register int win = 0;
- register rtx r0, r1;
+ register rtx r0, r1 = NULL_RTX;
int combined_regno = -1;
int i;
- int insn_code_number = recog_memoized (insn);
this_insn_number = insn_number;
this_insn = insn;
- if (insn_code_number >= 0)
- insn_extract (insn);
+ extract_insn (insn);
which_alternative = -1;
/* Is this insn suitable for tying two registers?
If tying is done, WIN is set nonzero. */
- if (insn_code_number >= 0
-#ifdef REGISTER_CONSTRAINTS
- && insn_n_operands[insn_code_number] > 1
- && insn_operand_constraint[insn_code_number][0][0] == '='
- && insn_operand_constraint[insn_code_number][0][1] != '&'
-#else
- && GET_CODE (PATTERN (insn)) == SET
- && rtx_equal_p (SET_DEST (PATTERN (insn)), recog_operand[0])
-#endif
- )
+ if (optimize
+ && recog_data.n_operands > 1
+ && recog_data.constraints[0][0] == '='
+ && recog_data.constraints[0][1] != '&')
{
-#ifdef REGISTER_CONSTRAINTS
/* If non-negative, is an operand that must match operand 0. */
int must_match_0 = -1;
/* Counts number of alternatives that require a match with
operand 0. */
int n_matching_alts = 0;
- for (i = 1; i < insn_n_operands[insn_code_number]; i++)
+ for (i = 1; i < recog_data.n_operands; i++)
{
- char *p = insn_operand_constraint[insn_code_number][i];
+ const char *p = recog_data.constraints[i];
int this_match = (requires_inout (p));
n_matching_alts += this_match;
- if (this_match == insn_n_alternatives[insn_code_number])
+ if (this_match == recog_data.n_alternatives)
must_match_0 = i;
}
-#endif
- r0 = recog_operand[0];
- for (i = 1; i < insn_n_operands[insn_code_number]; i++)
+ r0 = recog_data.operand[0];
+ for (i = 1; i < recog_data.n_operands; i++)
{
-#ifdef REGISTER_CONSTRAINTS
/* Skip this operand if we found an operand that
must match operand 0 and this operand isn't it
and can't be made to be it by commutativity. */
if (must_match_0 >= 0 && i != must_match_0
&& ! (i == must_match_0 + 1
- && insn_operand_constraint[insn_code_number][i-1][0] == '%')
+ && recog_data.constraints[i-1][0] == '%')
&& ! (i == must_match_0 - 1
- && insn_operand_constraint[insn_code_number][i][0] == '%'))
+ && recog_data.constraints[i][0] == '%'))
continue;
/* Likewise if each alternative has some operand that
- must match operand zero. In that case, skip any
+ must match operand zero. In that case, skip any
operand that doesn't list operand 0 since we know that
the operand always conflicts with operand 0. We
ignore commutatity in this case to keep things simple. */
- if (n_matching_alts == insn_n_alternatives[insn_code_number]
- && (0 == requires_inout
- (insn_operand_constraint[insn_code_number][i])))
+ if (n_matching_alts == recog_data.n_alternatives
+ && 0 == requires_inout (recog_data.constraints[i]))
continue;
-#endif
- r1 = recog_operand[i];
+ r1 = recog_data.operand[i];
/* If the operand is an address, find a register in it.
There may be more than one register, but we only try one
of them. */
- if (
-#ifdef REGISTER_CONSTRAINTS
- insn_operand_constraint[insn_code_number][i][0] == 'p'
-#else
- insn_operand_address_p[insn_code_number][i]
-#endif
- )
+ if (recog_data.constraints[i][0] == 'p')
while (GET_CODE (r1) == PLUS || GET_CODE (r1) == MULT)
r1 = XEXP (r1, 0);
can only be in the same register as the output, give
priority to an equivalence found from that insn. */
int may_save_copy
- = ((SET_DEST (body) == r0 && SET_SRC (body) == r1)
-#ifdef REGISTER_CONSTRAINTS
- || (r1 == recog_operand[i] && must_match_0 >= 0)
-#endif
- );
-
+ = (r1 == recog_data.operand[i] && must_match_0 >= 0);
+
if (GET_CODE (r1) == REG || GET_CODE (r1) == SUBREG)
win = combine_regs (r1, r0, may_save_copy,
insn_number, insn, 0);
destination register won't have had a quantity number
assigned, since that would prevent combining. */
- if (GET_CODE (PATTERN (insn)) == CLOBBER
+ if (optimize
+ && GET_CODE (PATTERN (insn)) == CLOBBER
&& (r0 = XEXP (PATTERN (insn), 0),
GET_CODE (r0) == REG)
&& (link = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == REG_DEAD
&& GET_CODE (XEXP (link, 0)) == REG
- && combined_regno != REGNO (XEXP (link, 0))
- && (no_conflict_combined_regno != REGNO (XEXP (link, 0))
- || ! find_reg_note (insn, REG_NO_CONFLICT, XEXP (link, 0))))
+ && combined_regno != (int) REGNO (XEXP (link, 0))
+ && (no_conflict_combined_regno != (int) REGNO (XEXP (link, 0))
+ || ! find_reg_note (insn, REG_NO_CONFLICT,
+ XEXP (link, 0))))
wipe_dead_reg (XEXP (link, 0), 0);
/* Allocate qty numbers for all registers local to this block
that are born (set) in this instruction.
A pseudo that already has a qty is not changed. */
- note_stores (PATTERN (insn), reg_is_set);
+ note_stores (PATTERN (insn), reg_is_set, NULL);
/* If anything is set in this insn and then unused, mark it as dying
after this insn, so it will conflict with our outputs. This
&& GET_CODE (XEXP (link, 0)) == REG)
wipe_dead_reg (XEXP (link, 0), 1);
- /* Allocate quantities for any SCRATCH operands of this insn. */
-
- if (insn_code_number >= 0)
- for (i = 0; i < insn_n_operands[insn_code_number]; i++)
- if (GET_CODE (recog_operand[i]) == SCRATCH
- && scratches_allocated++ < scratch_list_length)
- alloc_qty_for_scratch (recog_operand[i], i, insn,
- insn_code_number, insn_number);
-
- /* If this is an insn that has a REG_RETVAL note pointing at a
+ /* If this is an insn that has a REG_RETVAL note pointing at a
CLOBBER insn, we have reached the end of a REG_NO_CONFLICT
block, so clear any register number that combined within it. */
if ((note = find_reg_note (insn, REG_RETVAL, NULL_RTX)) != 0
IOR_HARD_REG_SET (regs_live_at[2 * insn_number], regs_live);
IOR_HARD_REG_SET (regs_live_at[2 * insn_number + 1], regs_live);
- if (insn == basic_block_end[b])
+ if (insn == BLOCK_END (b))
break;
insn = NEXT_INSN (insn);
/* Now every register that is local to this basic block
should have been given a quantity, or else -1 meaning ignore it.
- Every quantity should have a known birth and death.
+ Every quantity should have a known birth and death.
Order the qtys so we assign them registers in order of the
number of suggested registers they need so we allocate those with
the most restrictive needs first. */
- qty_order = (int *) alloca (next_qty * sizeof (int));
+ qty_order = (int *) xmalloc (next_qty * sizeof (int));
for (i = 0; i < next_qty; i++)
qty_order[i] = i;
{
q = qty_order[i];
if (qty_phys_num_sugg[q] != 0 || qty_phys_num_copy_sugg[q] != 0)
- qty_phys_reg[q] = find_free_reg (qty_min_class[q], qty_mode[q], q,
- 0, 1, qty_birth[q], qty_death[q]);
+ qty[q].phys_reg = find_free_reg (qty[q].min_class, qty[q].mode, q,
+ 0, 1, qty[q].birth, qty[q].death);
else
- qty_phys_reg[q] = -1;
+ qty[q].phys_reg = -1;
}
- /* Order the qtys so we assign them registers in order of
- decreasing length of life. Normally call qsort, but if we
+ /* Order the qtys so we assign them registers in order of
+ decreasing length of life. Normally call qsort, but if we
have only a very small number of quantities, sort them ourselves. */
for (i = 0; i < next_qty; i++)
for (i = 0; i < next_qty; i++)
{
q = qty_order[i];
- if (qty_phys_reg[q] < 0)
+ if (qty[q].phys_reg < 0)
{
+#ifdef INSN_SCHEDULING
+ /* These values represent the adjusted lifetime of a qty so
+ that it conflicts with qtys which appear near the start/end
+ of this qty's lifetime.
+
+ The purpose behind extending the lifetime of this qty is to
+ discourage the register allocator from creating false
+ dependencies.
+
+ The adjustment value is choosen to indicate that this qty
+ conflicts with all the qtys in the instructions immediately
+ before and after the lifetime of this qty.
+
+ Experiments have shown that higher values tend to hurt
+ overall code performance.
+
+ If allocation using the extended lifetime fails we will try
+ again with the qty's unadjusted lifetime. */
+ int fake_birth = MAX (0, qty[q].birth - 2 + qty[q].birth % 2);
+ int fake_death = MIN (insn_number * 2 + 1,
+ qty[q].death + 2 - qty[q].death % 2);
+#endif
+
if (N_REG_CLASSES > 1)
{
- qty_phys_reg[q] = find_free_reg (qty_min_class[q],
- qty_mode[q], q, 0, 0,
- qty_birth[q], qty_death[q]);
- if (qty_phys_reg[q] >= 0)
+#ifdef INSN_SCHEDULING
+ /* We try to avoid using hard registers allocated to qtys which
+ are born immediately after this qty or die immediately before
+ this qty.
+
+ This optimization is only appropriate when we will run
+ a scheduling pass after reload and we are not optimizing
+ for code size. */
+ if (flag_schedule_insns_after_reload
+ && !optimize_size
+ && !SMALL_REGISTER_CLASSES)
+ {
+ qty[q].phys_reg = find_free_reg (qty[q].min_class,
+ qty[q].mode, q, 0, 0,
+ fake_birth, fake_death);
+ if (qty[q].phys_reg >= 0)
+ continue;
+ }
+#endif
+ qty[q].phys_reg = find_free_reg (qty[q].min_class,
+ qty[q].mode, q, 0, 0,
+ qty[q].birth, qty[q].death);
+ if (qty[q].phys_reg >= 0)
continue;
}
- if (qty_alternate_class[q] != NO_REGS)
- qty_phys_reg[q] = find_free_reg (qty_alternate_class[q],
- qty_mode[q], q, 0, 0,
- qty_birth[q], qty_death[q]);
+#ifdef INSN_SCHEDULING
+ /* Similarly, avoid false dependencies. */
+ if (flag_schedule_insns_after_reload
+ && !optimize_size
+ && !SMALL_REGISTER_CLASSES
+ && qty[q].alternate_class != NO_REGS)
+ qty[q].phys_reg = find_free_reg (qty[q].alternate_class,
+ qty[q].mode, q, 0, 0,
+ fake_birth, fake_death);
+#endif
+ if (qty[q].alternate_class != NO_REGS)
+ qty[q].phys_reg = find_free_reg (qty[q].alternate_class,
+ qty[q].mode, q, 0, 0,
+ qty[q].birth, qty[q].death);
}
}
to the pseudo regs belonging to the qtys. */
for (q = 0; q < next_qty; q++)
- if (qty_phys_reg[q] >= 0)
+ if (qty[q].phys_reg >= 0)
{
- for (i = qty_first_reg[q]; i >= 0; i = reg_next_in_qty[i])
- reg_renumber[i] = qty_phys_reg[q] + reg_offset[i];
- if (qty_scratch_rtx[q])
- {
- if (GET_CODE (qty_scratch_rtx[q]) == REG)
- abort ();
- PUT_CODE (qty_scratch_rtx[q], REG);
- REGNO (qty_scratch_rtx[q]) = qty_phys_reg[q];
-
- scratch_block[scratch_index] = b;
- scratch_list[scratch_index++] = qty_scratch_rtx[q];
-
- /* Must clear the USED field, because it will have been set by
- copy_rtx_if_shared, but the leaf_register code expects that
- it is zero in all REG rtx. copy_rtx_if_shared does not set the
- used bit for REGs, but does for SCRATCHes. */
- qty_scratch_rtx[q]->used = 0;
- }
+ for (i = qty[q].first_reg; i >= 0; i = reg_next_in_qty[i])
+ reg_renumber[i] = qty[q].phys_reg + reg_offset[i];
}
+
+ /* Clean up. */
+ free (regs_live_at);
+ free (qty_order);
}
\f
/* Compare two quantities' priority for getting real registers.
QTY_CMP_PRI is also used by qty_sugg_compare. */
#define QTY_CMP_PRI(q) \
- ((int) (((double) (floor_log2 (qty_n_refs[q]) * qty_n_refs[q] * qty_size[q]) \
- / (qty_death[q] - qty_birth[q])) * 10000))
+ ((int) (((double) (floor_log2 (qty[q].n_refs) * qty[q].n_refs * qty[q].size) \
+ / (qty[q].death - qty[q].birth)) * 10000))
static int
qty_compare (q1, q2)
static int
qty_compare_1 (q1p, q2p)
- const GENERIC_PTR q1p;
- const GENERIC_PTR q2p;
+ const PTR q1p;
+ const PTR q2p;
{
- register int q1 = *(int *)q1p, q2 = *(int *)q2p;
+ register int q1 = *(const int *) q1p, q2 = *(const int *) q2p;
register int tem = QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1);
if (tem != 0)
if (tem != 0)
return tem;
-
+
return QTY_CMP_PRI (q2) - QTY_CMP_PRI (q1);
}
static int
qty_sugg_compare_1 (q1p, q2p)
- const GENERIC_PTR q1p;
- const GENERIC_PTR q2p;
+ const PTR q1p;
+ const PTR q2p;
{
- register int q1 = *(int *)q1p, q2 = *(int *)q2p;
+ register int q1 = *(const int *) q1p, q2 = *(const int *) q2p;
register int tem = QTY_CMP_SUGG (q1) - QTY_CMP_SUGG (q2);
if (tem != 0)
MAY_SAVE_COPYCOPY is non-zero if this insn is simply copying USEDREG to
SETREG or if the input and output must share a register.
In that case, we record a hard reg suggestion in QTY_PHYS_COPY_SUGG.
-
+
There are elaborate checks for the validity of combining. */
-
static int
combine_regs (usedreg, setreg, may_save_copy, insn_number, insn, already_dead)
rtx usedreg, setreg;
/* Do not combine with a smaller already-assigned object
if that smaller object is already combined with something bigger. */
|| (ssize > usize && ureg >= FIRST_PSEUDO_REGISTER
- && usize < qty_size[reg_qty[ureg]])
+ && usize < qty[reg_qty[ureg]].size)
/* Can't combine if SREG is not a register we can allocate. */
|| (sreg >= FIRST_PSEUDO_REGISTER && reg_qty[sreg] == -1)
/* Don't combine with a pseudo mentioned in a REG_NO_CONFLICT note.
are compatible. */
if ((already_dead || find_regno_note (insn, REG_DEAD, ureg))
- && reg_meets_class_p (sreg, qty_min_class[reg_qty[ureg]]))
+ && reg_meets_class_p (sreg, qty[reg_qty[ureg]].min_class))
{
/* Add SREG to UREG's quantity. */
sqty = reg_qty[ureg];
reg_qty[sreg] = sqty;
reg_offset[sreg] = reg_offset[ureg] + offset;
- reg_next_in_qty[sreg] = qty_first_reg[sqty];
- qty_first_reg[sqty] = sreg;
+ reg_next_in_qty[sreg] = qty[sqty].first_reg;
+ qty[sqty].first_reg = sreg;
- /* If SREG's reg class is smaller, set qty_min_class[SQTY]. */
+ /* If SREG's reg class is smaller, set qty[SQTY].min_class. */
update_qty_class (sqty, sreg);
/* Update info about quantity SQTY. */
- qty_n_calls_crossed[sqty] += REG_N_CALLS_CROSSED (sreg);
- qty_n_refs[sqty] += REG_N_REFS (sreg);
+ qty[sqty].n_calls_crossed += REG_N_CALLS_CROSSED (sreg);
+ qty[sqty].n_refs += REG_N_REFS (sreg);
if (usize < ssize)
{
register int i;
- for (i = qty_first_reg[sqty]; i >= 0; i = reg_next_in_qty[i])
+ for (i = qty[sqty].first_reg; i >= 0; i = reg_next_in_qty[i])
reg_offset[i] -= offset;
- qty_size[sqty] = ssize;
- qty_mode[sqty] = GET_MODE (setreg);
+ qty[sqty].size = ssize;
+ qty[sqty].mode = GET_MODE (setreg);
}
}
else
|| reg_class_subset_p (class, rclass));
}
-/* Return 1 if the two specified classes have registers in common.
- If CALL_SAVED, then consider only call-saved registers. */
-
-static int
-reg_classes_overlap_p (c1, c2, call_saved)
- register enum reg_class c1;
- register enum reg_class c2;
- int call_saved;
-{
- HARD_REG_SET c;
- int i;
-
- COPY_HARD_REG_SET (c, reg_class_contents[(int) c1]);
- AND_HARD_REG_SET (c, reg_class_contents[(int) c2]);
-
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (TEST_HARD_REG_BIT (c, i)
- && (! call_saved || ! call_used_regs[i]))
- return 1;
-
- return 0;
-}
-
-/* Update the class of QTY assuming that REG is being tied to it. */
+/* Update the class of QTYNO assuming that REG is being tied to it. */
static void
-update_qty_class (qty, reg)
- int qty;
+update_qty_class (qtyno, reg)
+ int qtyno;
int reg;
{
enum reg_class rclass = reg_preferred_class (reg);
- if (reg_class_subset_p (rclass, qty_min_class[qty]))
- qty_min_class[qty] = rclass;
+ if (reg_class_subset_p (rclass, qty[qtyno].min_class))
+ qty[qtyno].min_class = rclass;
rclass = reg_alternate_class (reg);
- if (reg_class_subset_p (rclass, qty_alternate_class[qty]))
- qty_alternate_class[qty] = rclass;
+ if (reg_class_subset_p (rclass, qty[qtyno].alternate_class))
+ qty[qtyno].alternate_class = rclass;
- if (REG_CHANGES_SIZE (reg))
- qty_changes_size[qty] = 1;
+ if (REG_CHANGES_MODE (reg))
+ qty[qtyno].changes_mode = 1;
}
\f
/* Handle something which alters the value of an rtx REG.
carry info from `block_alloc'. */
static void
-reg_is_set (reg, setter)
+reg_is_set (reg, setter, data)
rtx reg;
rtx setter;
+ void *data ATTRIBUTE_UNUSED;
{
/* Note that note_stores will only pass us a SUBREG if it is a SUBREG of
a hard register. These may actually not exist any more. */
int birth;
{
register int regno;
-
+
if (GET_CODE (reg) == SUBREG)
regno = REGNO (SUBREG_REG (reg)) + SUBREG_WORD (reg);
else
/* If this register has a quantity number, show that it isn't dead. */
if (reg_qty[regno] >= 0)
- qty_death[reg_qty[regno]] = -1;
+ qty[reg_qty[regno]].death = -1;
}
}
/* If this insn has multiple results,
and the dead reg is used in one of the results,
extend its life to after this insn,
- so it won't get allocated together with any other result of this insn. */
+ so it won't get allocated together with any other result of this insn.
+
+ It is unsafe to use !single_set here since it will ignore an unused
+ output. Just because an output is unused does not mean the compiler
+ can assume the side effect will not occur. Consider if REG appears
+ in the address of an output and we reload the output. If we allocate
+ REG to the same hard register as an unused output we could set the hard
+ register before the output reload insn. */
if (GET_CODE (PATTERN (this_insn)) == PARALLEL
- && !single_set (this_insn))
+ && multiple_sets (this_insn))
{
int i;
for (i = XVECLEN (PATTERN (this_insn), 0) - 1; i >= 0; i--)
not to happen). */
if (output_p)
post_mark_life (regno, GET_MODE (reg), 1,
- 2 * this_insn_number, 2 * this_insn_number+ 1);
+ 2 * this_insn_number, 2 * this_insn_number + 1);
}
else if (reg_qty[regno] >= 0)
- qty_death[reg_qty[regno]] = 2 * this_insn_number + output_p;
+ qty[reg_qty[regno]].death = 2 * this_insn_number + output_p;
}
\f
/* Find a block of SIZE words of hard regs in reg_class CLASS
(but actually we test only the first of the block for holding MODE)
and still free between insn BORN_INDEX and insn DEAD_INDEX,
and return the number of the first of them.
- Return -1 if such a block cannot be found.
- If QTY crosses calls, insist on a register preserved by calls,
+ Return -1 if such a block cannot be found.
+ If QTYNO crosses calls, insist on a register preserved by calls,
unless ACCEPT_CALL_CLOBBERED is nonzero.
If JUST_TRY_SUGGESTED is non-zero, only try to see if the suggested
register is available. If not, return -1. */
static int
-find_free_reg (class, mode, qty, accept_call_clobbered, just_try_suggested,
+find_free_reg (class, mode, qtyno, accept_call_clobbered, just_try_suggested,
born_index, dead_index)
enum reg_class class;
enum machine_mode mode;
- int qty;
+ int qtyno;
int accept_call_clobbered;
int just_try_suggested;
int born_index, dead_index;
{
register int i, ins;
#ifdef HARD_REG_SET
- register /* Declare it register if it's a scalar. */
+ /* Declare it register if it's a scalar. */
+ register
#endif
HARD_REG_SET used, first_used;
#ifdef ELIMINABLE_REGS
/* Don't let a pseudo live in a reg across a function call
if we might get a nonlocal goto. */
if (current_function_has_nonlocal_label
- && qty_n_calls_crossed[qty] > 0)
+ && qty[qtyno].n_calls_crossed > 0)
return -1;
if (accept_call_clobbered)
COPY_HARD_REG_SET (used, call_fixed_reg_set);
- else if (qty_n_calls_crossed[qty] == 0)
+ else if (qty[qtyno].n_calls_crossed == 0)
COPY_HARD_REG_SET (used, fixed_reg_set);
else
COPY_HARD_REG_SET (used, call_used_reg_set);
This is true of any register that can be eliminated. */
#ifdef ELIMINABLE_REGS
- for (i = 0; i < sizeof eliminables / sizeof eliminables[0]; i++)
+ for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++)
SET_HARD_REG_BIT (used, eliminables[i].from);
#if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
/* If FRAME_POINTER_REGNUM is not a real register, then protect the one
SET_HARD_REG_BIT (used, FRAME_POINTER_REGNUM);
#endif
-#ifdef CLASS_CANNOT_CHANGE_SIZE
- if (qty_changes_size[qty])
+#ifdef CLASS_CANNOT_CHANGE_MODE
+ if (qty[qtyno].changes_mode)
IOR_HARD_REG_SET (used,
- reg_class_contents[(int) CLASS_CANNOT_CHANGE_SIZE]);
+ reg_class_contents[(int) CLASS_CANNOT_CHANGE_MODE]);
#endif
/* Normally, the registers that can be used for the first register in
if (just_try_suggested)
{
- if (qty_phys_num_copy_sugg[qty] != 0)
- IOR_COMPL_HARD_REG_SET (first_used, qty_phys_copy_sugg[qty]);
+ if (qty_phys_num_copy_sugg[qtyno] != 0)
+ IOR_COMPL_HARD_REG_SET (first_used, qty_phys_copy_sugg[qtyno]);
else
- IOR_COMPL_HARD_REG_SET (first_used, qty_phys_sugg[qty]);
+ IOR_COMPL_HARD_REG_SET (first_used, qty_phys_sugg[qtyno]);
}
/* If all registers are excluded, we can't do anything. */
int regno = i;
#endif
if (! TEST_HARD_REG_BIT (first_used, regno)
- && HARD_REGNO_MODE_OK (regno, mode))
+ && HARD_REGNO_MODE_OK (regno, mode)
+ && (qty[qtyno].n_calls_crossed == 0
+ || accept_call_clobbered
+ || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
{
register int j;
register int size1 = HARD_REGNO_NREGS (regno, mode);
return regno;
}
#ifndef REG_ALLOC_ORDER
- i += j; /* Skip starting points we know will lose */
+ /* Skip starting points we know will lose. */
+ i += j;
#endif
}
}
fail:
-
/* If we are just trying suggested register, we have just tried copy-
suggested registers, and there are arithmetic-suggested registers,
try them. */
-
+
/* If it would be profitable to allocate a call-clobbered register
and save and restore it around calls, do that. */
- if (just_try_suggested && qty_phys_num_copy_sugg[qty] != 0
- && qty_phys_num_sugg[qty] != 0)
+ if (just_try_suggested && qty_phys_num_copy_sugg[qtyno] != 0
+ && qty_phys_num_sugg[qtyno] != 0)
{
/* Don't try the copy-suggested regs again. */
- qty_phys_num_copy_sugg[qty] = 0;
- return find_free_reg (class, mode, qty, accept_call_clobbered, 1,
+ qty_phys_num_copy_sugg[qtyno] = 0;
+ return find_free_reg (class, mode, qtyno, accept_call_clobbered, 1,
born_index, dead_index);
}
if (! accept_call_clobbered
&& flag_caller_saves
&& ! just_try_suggested
- && qty_n_calls_crossed[qty] != 0
- && CALLER_SAVE_PROFITABLE (qty_n_refs[qty], qty_n_calls_crossed[qty]))
+ && qty[qtyno].n_calls_crossed != 0
+ && CALLER_SAVE_PROFITABLE (qty[qtyno].n_refs,
+ qty[qtyno].n_calls_crossed))
{
- i = find_free_reg (class, mode, qty, 1, 0, born_index, dead_index);
+ i = find_free_reg (class, mode, qtyno, 1, 0, born_index, dead_index);
if (i >= 0)
caller_save_needed = 1;
return i;
{
register int j = HARD_REGNO_NREGS (regno, mode);
#ifdef HARD_REG_SET
- register /* Declare it register if it's a scalar. */
+ /* Declare it register if it's a scalar. */
+ register
#endif
HARD_REG_SET this_reg;
static int
no_conflict_p (insn, r0, r1)
- rtx insn, r0, r1;
+ rtx insn, r0 ATTRIBUTE_UNUSED, r1;
{
int ok = 0;
rtx note = find_reg_note (insn, REG_LIBCALL, NULL_RTX);
last = XEXP (note, 0);
for (p = NEXT_INSN (insn); p && p != last; p = NEXT_INSN (p))
- if (GET_RTX_CLASS (GET_CODE (p)) == 'i')
+ if (INSN_P (p))
{
if (find_reg_note (p, REG_DEAD, r1))
ok = 1;
if (! find_reg_note (p, REG_NO_CONFLICT, r1))
return 0;
}
-
+
return ok;
}
\f
-#ifdef REGISTER_CONSTRAINTS
-
/* Return the number of alternatives for which the constraint string P
indicates that the operand must be equal to operand 0 and that no register
is acceptable. */
static int
requires_inout (p)
- char *p;
+ const char *p;
{
char c;
int found_zero = 0;
int reg_allowed = 0;
int num_matching_alts = 0;
- while (c = *p++)
+ while ((c = *p++))
switch (c)
{
case '=': case '+': case '?':
case '#': case '&': case '!':
case '*': case '%':
- case '1': case '2': case '3': case '4':
+ case '1': case '2': case '3': case '4': case '5':
+ case '6': case '7': case '8': case '9':
case 'm': case '<': case '>': case 'V': case 'o':
case 'E': case 'F': case 'G': case 'H':
case 's': case 'i': case 'n':
case 'I': case 'J': case 'K': case 'L':
case 'M': case 'N': case 'O': case 'P':
-#ifdef EXTRA_CONSTRAINT
- case 'Q': case 'R': case 'S': case 'T': case 'U':
-#endif
case 'X':
/* These don't say anything we care about. */
break;
found_zero = 1;
break;
+ default:
+ if (REG_CLASS_FROM_LETTER (c) == NO_REGS)
+ break;
+ /* FALLTHRU */
case 'p':
case 'g': case 'r':
- default:
reg_allowed = 1;
break;
}
return num_matching_alts;
}
-#endif /* REGISTER_CONSTRAINTS */
\f
void
dump_local_alloc (file)
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