/* Register renaming for the GNU compiler.
Copyright (C) 2000 Free Software Foundation, Inc.
This file is part of GNU CC.
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
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.
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. */
#include "config.h"
#include "system.h"
#include "tree.h"
#include "rtl.h"
#include "basic-block.h"
#include "insn-config.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "flags.h"
#include "output.h"
#include "function.h"
#include "recog.h"
#include "resource.h"
static const char *const reg_class_names[] = REG_CLASS_NAMES;
/* ??? Consider a more sparse data structure? */
typedef struct def_uses
{
/* high bound of defs and uses */
int high_bound;
/* 1 if insn y defines a reg whose use crosses a call
y is the ordinal position of the insn within the block */
sbitmap require_call_save_reg;
/* REGNO x INSN y 1 if insn y sets reg x */
sbitmap *defs;
/* REGNO x INSN y The register class for this def */
enum reg_class *def_class;
/* REGNO x INSN y 1 if insn y uses reg x */
sbitmap *uses;
/* REGNO x INSN y The register class for this use */
enum reg_class *use_class;
}
def_uses;
#define DU_REG_CLASS(rc,r,high_bound,i) (rc[r * high_bound + i])
typedef struct ext_basic_blocks
{
/* n_basic_blocks x n_basic_blocks y 1 if bb y is in extended bb
having entry x */
sbitmap *basic_block;
/* n_basic_blocks x n_basic_blocks y 1 if bb y is an exit block */
sbitmap *exit;
}
ext_basic_blocks;
#define UID_RUID_HIGH_BOUND 64
#define DESTINATION 1
#define SOURCE 2
static void build_def_use PARAMS ((int, ext_basic_blocks *,
HARD_REG_SET *, def_uses *,
sbitmap *));
static int replace_reg_in_block PARAMS ((def_uses *, varray_type *,
int, rtx, unsigned int));
static int consider_def PARAMS ((rtx, int, def_uses *, int));
static int consider_available PARAMS ((rtx, int, HARD_REG_SET *,
int, def_uses *, int));
static rtx rr_replace_reg PARAMS ((rtx, rtx, rtx, int, rtx,
int *));
static int consider_use PARAMS ((rtx, int, int, int));
static int condmove_p PARAMS ((rtx));
static void dump_def_use_chain PARAMS ((HARD_REG_SET *, def_uses *,
varray_type *));
static void dump_ext_bb_info PARAMS ((int, ext_basic_blocks *));
static void find_ext_basic_blocks PARAMS ((ext_basic_blocks *));
static void find_one_ext_basic_block PARAMS ((int, basic_block, sbitmap *,
ext_basic_blocks *));
static enum reg_class get_reg_class PARAMS ((rtx, rtx, int,
enum reg_class));
static rtx regno_first_use_in PARAMS ((unsigned int, rtx));
void
regrename_optimize ()
{
int b, eb, i, inum, r, rc, replace_ok;
rtx insn;
def_uses du;
ext_basic_blocks ebb;
/* Registers used in a given class */
HARD_REG_SET class_regs;
/* Registers available for use as renaming registers */
HARD_REG_SET avail_regs;
/* Registers used in the block */
HARD_REG_SET regs_used;
/* Registers which have been used as renaming registers */
HARD_REG_SET renamed_regs;
HARD_REG_SET global_live_at_end, global_live_at_start;
HARD_REG_SET null_bitmap, tmp_bitmap;
/* 1 if insn y sets a register which is live at the end of the block */
sbitmap defs_live_exit;
/* Mapping from insn y (ordinal position in block) to INSN_UID */
varray_type uid_ruid;
/* Mapping from insn y (ordinal position in block) to block id */
varray_type uid_rbid;
/* Ordinal position in block of defining insn */
int *def_idx;
VARRAY_RTX_INIT (uid_ruid, UID_RUID_HIGH_BOUND + 1, "uid_ruid");
VARRAY_LONG_INIT (uid_rbid, UID_RUID_HIGH_BOUND + 1, "uid_rbid");
ebb.basic_block
= sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
sbitmap_vector_zero (ebb.basic_block, n_basic_blocks);
ebb.exit
= sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
sbitmap_vector_zero (ebb.exit, n_basic_blocks);
find_ext_basic_blocks (&ebb);
du.def_class = du.use_class = 0;
/* Build uid_ruid and uid_rbid for this extended basic block */
for (b = 0; b < n_basic_blocks; b++)
if (TEST_BIT (ebb.basic_block[b], b))
{
for (eb = du.high_bound = 0; eb < n_basic_blocks; eb++)
if (TEST_BIT (ebb.basic_block[b], eb))
{
basic_block bb = BASIC_BLOCK (eb);
/* Calculate high bound for uid_ruid and allocate if necessary */
for (insn = bb->head;
insn != NEXT_INSN (bb->end);
du.high_bound++, insn = NEXT_INSN (insn))
{
int uid_ruid_high_bound = VARRAY_SIZE (uid_ruid);
if (du.high_bound + 4 >= uid_ruid_high_bound)
{
VARRAY_GROW (uid_ruid, uid_ruid_high_bound * 2);
VARRAY_GROW (uid_rbid, uid_ruid_high_bound * 2);
}
VARRAY_RTX (uid_ruid, du.high_bound) = insn;
VARRAY_LONG (uid_rbid, du.high_bound) = eb;
}
}
CLEAR_HARD_REG_SET (null_bitmap);
CLEAR_HARD_REG_SET (class_regs);
CLEAR_HARD_REG_SET (regs_used);
CLEAR_HARD_REG_SET (avail_regs);
CLEAR_HARD_REG_SET (tmp_bitmap);
CLEAR_HARD_REG_SET (renamed_regs);
du.defs
= sbitmap_vector_alloc (FIRST_PSEUDO_REGISTER, du.high_bound + 1);
sbitmap_vector_zero (du.defs, FIRST_PSEUDO_REGISTER);
du.uses
= sbitmap_vector_alloc (FIRST_PSEUDO_REGISTER, du.high_bound + 1);
sbitmap_vector_zero (du.uses, FIRST_PSEUDO_REGISTER);
du.require_call_save_reg = sbitmap_alloc (du.high_bound + 1);
sbitmap_zero (du.require_call_save_reg);
defs_live_exit = sbitmap_alloc (du.high_bound + 1);
sbitmap_zero (defs_live_exit);
du.def_class
= xrealloc (du.def_class,
(sizeof (enum reg_class) * FIRST_PSEUDO_REGISTER
* du.high_bound));
du.use_class
= xrealloc (du.use_class,
(sizeof (enum reg_class) * FIRST_PSEUDO_REGISTER
* du.high_bound));
build_def_use (b, &ebb, ®s_used, &du, &defs_live_exit);
if (rtl_dump_file)
{
dump_ext_bb_info (b, &ebb);
dump_def_use_chain (&global_live_at_end, &du, &uid_ruid);
}
/* Available registers are not: used in the block, live at the start,
live at the end, a register we've renamed to. */
/* ??? The current algorithm is pessimistic for extended basic blocks
as it just treats them as a big basic block. */
COPY_HARD_REG_SET (tmp_bitmap, regs_used);
REG_SET_TO_HARD_REG_SET (global_live_at_start,
BASIC_BLOCK (b)->global_live_at_start);
IOR_HARD_REG_SET (tmp_bitmap, global_live_at_start);
for (eb = 0; eb < n_basic_blocks; eb++)
if (TEST_BIT (ebb.basic_block[b], eb))
{
basic_block bb = BASIC_BLOCK (eb);
REG_SET_TO_HARD_REG_SET (global_live_at_end,
bb->global_live_at_end);
IOR_HARD_REG_SET (tmp_bitmap, global_live_at_end);
}
def_idx = xcalloc (du.high_bound, sizeof (int));
/* Only consider registers in this extended block and in this class
that are defined more than once. Replace them if permissible. */
for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
{
int avail_reg, ar_idx, def, def_cnt = 0, use_idx, call_idx;
if (!TEST_HARD_REG_BIT (regs_used, r)
|| fixed_regs[r]
|| r == FRAME_POINTER_REGNUM)
continue;
/* Find def_idx[N] where hbound of N is the number of
definitions of this register in this block. and def_idx
is the ordinal position of this insn in the block. */
for (i = 0, def_idx[def_cnt] = 0; i < du.high_bound; i++)
if (TEST_BIT (du.defs[r], i)
&& consider_def (VARRAY_RTX (uid_ruid, i), r, &du, i))
{
int first_use = 1;
def_idx[def_cnt] = i;
/* Only consider definitions that have a use. */
for (use_idx = i + 1; use_idx < du.high_bound; use_idx++)
{
if (TEST_BIT (du.uses[r], use_idx))
{
if (consider_use (VARRAY_RTX (uid_ruid, use_idx), r,
VARRAY_LONG (uid_rbid, i),
VARRAY_LONG (uid_rbid, use_idx)))
{
if (first_use)
{
first_use = 0;
def_cnt++;
}
}
else
{
/* Don't consider def if we don't want this
use. */
if (!first_use)
def_cnt--;
break;
}
}
if (TEST_BIT (du.defs[r], use_idx))
break;
}
/* Scan until the next def to avoid renaming
parameter registers. */
/* ??? consider using CALL_INSN_FUNCTION_USAGE */
for (call_idx = i; call_idx <= use_idx; call_idx++)
if (VARRAY_RTX (uid_ruid, call_idx)
&& (GET_CODE (VARRAY_RTX (uid_ruid, call_idx))
== CALL_INSN))
SET_BIT (du.require_call_save_reg, i);
}
if (def_cnt < 2)
continue;
/* We have more than one def so rename until we exhaust
renaming registers. */
/* ??? Should we continue renaming round robin when we exhaust
renaming registers? */
for (def = 0; def < def_cnt - 1; def++)
{
if (!TEST_BIT (defs_live_exit, def_idx[def])
&& (GET_RTX_CLASS
(GET_CODE (VARRAY_RTX (uid_ruid,
def_idx[def]))) == 'i'))
{
rtx reg_use
= regno_first_use_in
(r, PATTERN (VARRAY_RTX (uid_ruid, def_idx[def])));
if (!reg_use)
break;
#ifdef STACK_REGS
/* Don't bother with stacked float registers */
if (GET_MODE_CLASS (GET_MODE (reg_use)) == MODE_FLOAT)
break;
#endif
rc = (int) DU_REG_CLASS (du.def_class,
r, du.high_bound, def_idx[def]);
COPY_HARD_REG_SET (avail_regs,
reg_class_contents[(enum reg_class) rc]);
AND_COMPL_HARD_REG_SET (avail_regs, tmp_bitmap);
AND_COMPL_HARD_REG_SET (avail_regs, renamed_regs);
/* No available registers in this class */
GO_IF_HARD_REG_EQUAL (avail_regs, null_bitmap,
no_available_regs);
for (ar_idx = 0; ar_idx < FIRST_PSEUDO_REGISTER
&& TEST_HARD_REG_BIT (avail_regs, ar_idx); ar_idx++)
;
if (ar_idx == FIRST_PSEUDO_REGISTER)
goto no_available_regs;
/* Only try register renaming if there is an available
register in this class. */
for (ar_idx = 0; ar_idx < FIRST_PSEUDO_REGISTER; ar_idx++)
{
#ifdef REG_ALLOC_ORDER
avail_reg = reg_alloc_order[ar_idx];
#else
avail_reg = ar_idx;
#endif
if (consider_available (reg_use, avail_reg,
&avail_regs, rc, &du,
def_idx[def]))
break;
}
if (ar_idx == FIRST_PSEUDO_REGISTER)
{
if (rtl_dump_file)
{
fprintf (rtl_dump_file,
"Register %s in class %s",
reg_names[r], reg_class_names[rc]);
fprintf (rtl_dump_file,
" in insn %d",
INSN_UID (VARRAY_RTX (uid_ruid,
def_idx[def])));
if (TEST_BIT (du.require_call_save_reg,
def_idx[def]))
fprintf (rtl_dump_file, " crosses a call");
fprintf (rtl_dump_file,
". No available registers\n");
}
goto try_next_def;
}
SET_HARD_REG_BIT (renamed_regs, avail_reg);
CLEAR_HARD_REG_BIT (avail_regs, avail_reg);
/* Replace in destination. Replace in source for
remainder of block until new register is defined
again */
replace_ok
= replace_reg_in_block (&du, &uid_ruid, def_idx[def],
reg_use, avail_reg);
/* Replace failed, so restore previous register */
if (!replace_ok)
{
replace_reg_in_block (&du, &uid_ruid, def_idx[def],
gen_rtx_REG (GET_MODE (reg_use),
avail_reg),
REGNO (reg_use));
if (rtl_dump_file)
{
fprintf (rtl_dump_file,
"Register %s in class %s Renaming as %s ",
reg_names[r], reg_class_names[rc],
reg_names[avail_reg]);
fprintf (rtl_dump_file,
"would not satisfy constraints\n");
}
}
else if (rtl_dump_file)
{
fprintf (rtl_dump_file,
"Register %s in class %s Renamed as %s ",
reg_names[r], reg_class_names[rc],
reg_names[avail_reg]);
fprintf (rtl_dump_file, "at insn %d\n",
INSN_UID (VARRAY_RTX (uid_ruid,
def_idx[def])));
}
}
try_next_def:
continue;
}
sbitmap_zero (du.defs[r]);
no_available_regs:
continue;
}
free (def_idx);
sbitmap_vector_free (du.defs);
sbitmap_vector_free (du.uses);
sbitmap_free (du.require_call_save_reg);
sbitmap_free (defs_live_exit);
CLEAR_HARD_REG_SET (regs_used);
CLEAR_HARD_REG_SET (renamed_regs);
for (inum = 0; inum < (int) VARRAY_SIZE (uid_ruid); inum++)
VARRAY_RTX (uid_ruid, inum) = (rtx) 0;
}
sbitmap_vector_free (ebb.basic_block);
sbitmap_vector_free (ebb.exit);
}
/* Build def/use chain DU for extended basic block EBB having root B.
Also determine which regs are used, REGS_USED, and which insns define
a live at exit def, DEFS_LIVE_EXIT */
static void
build_def_use (b, ebb, regs_used, du, defs_live_exit)
int b;
ext_basic_blocks *ebb;
HARD_REG_SET *regs_used;
def_uses *du;
sbitmap *defs_live_exit;
{
rtx insn;
int eb, inum;
unsigned int r;
inum = 0;
for (eb = 0; eb < n_basic_blocks; eb++)
{
basic_block bb = BASIC_BLOCK (eb);
if (!TEST_BIT (ebb->basic_block[b], eb))
continue;
for (insn = bb->head;
insn != NEXT_INSN (bb->end);
inum++, insn = NEXT_INSN (insn))
{
struct resources insn_res;
struct resources insn_sets;
if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
continue;
CLEAR_RESOURCE (&insn_sets);
mark_set_resources (insn, &insn_sets, 0, MARK_DEST);
for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
{
if (!TEST_HARD_REG_BIT (insn_sets.regs, r))
continue;
SET_HARD_REG_BIT (*regs_used, r);
if (REGNO_REG_SET_P (bb->global_live_at_end, r))
SET_BIT (*defs_live_exit, inum);
if (!insn_sets.memory)
SET_BIT (du->defs[r], inum);
DU_REG_CLASS (du->def_class, r, du->high_bound, inum)
= get_reg_class (insn, regno_first_use_in (r, PATTERN (insn)),
DESTINATION, NO_REGS);
}
CLEAR_RESOURCE (&insn_res);
mark_referenced_resources (insn, &insn_res, 0);
for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
{
if (!TEST_HARD_REG_BIT (insn_res.regs, r))
continue;
SET_HARD_REG_BIT (*regs_used, r);
SET_BIT (du->uses[r], inum);
DU_REG_CLASS (du->use_class, r, du->high_bound, inum)
= get_reg_class (insn, regno_use_in (r, PATTERN (insn)),
SOURCE, NO_REGS);
}
}
}
free_resource_info ();
}
/* Return nonzero if regno AVAIL_REG can replace REG_DEF for insns in UID_RUID
starting at insn DEF in def/use chain DU. */
static int
replace_reg_in_block (du, uid_ruid, def, reg_def, avail_reg)
def_uses *du;
varray_type *uid_ruid;
int def;
rtx reg_def;
unsigned int avail_reg;
{
int du_idx, status = 1;
int last_replaced_insn;
unsigned int r = REGNO (reg_def);
rtx death_note;
rtx reg_notes;
rtx reg_use;
rtx new_reg = gen_rtx_REG (GET_MODE (reg_def), avail_reg);
rr_replace_reg (PATTERN (VARRAY_RTX (*uid_ruid, def)), reg_def, new_reg,
DESTINATION, VARRAY_RTX (*uid_ruid, def), &status);
if (!status)
return status;
death_note = 0;
/* This typically happens if a constraint check failed and the register
changes are being reversed. */
for (reg_notes = REG_NOTES (VARRAY_RTX (*uid_ruid, def));
reg_notes; reg_notes = XEXP (reg_notes, 1))
{
if (REG_NOTE_KIND (reg_notes) == REG_DEAD
&& REGNO (XEXP (reg_notes, 0)) == avail_reg)
death_note = reg_notes;
}
if (death_note)
remove_note (VARRAY_RTX (*uid_ruid, def), death_note);
/* The old destination is now dead if it is also a source. */
if (regno_use_in (r, PATTERN (VARRAY_RTX (*uid_ruid, def))))
REG_NOTES (VARRAY_RTX (*uid_ruid, def))
= gen_rtx_EXPR_LIST (REG_DEAD, reg_def,
REG_NOTES (VARRAY_RTX (*uid_ruid,
def)));
last_replaced_insn = 0;
/* Now replace in the uses. */
for (du_idx = def + 1; du_idx < du->high_bound; du_idx++)
{
if (GET_RTX_CLASS (GET_CODE (VARRAY_RTX (*uid_ruid, du_idx))) != 'i')
continue;
reg_use = regno_use_in (r, PATTERN (VARRAY_RTX (*uid_ruid, du_idx)));
if (reg_use && TEST_BIT (du->uses[r], du_idx))
{
new_reg = gen_rtx_REG (GET_MODE (reg_use), avail_reg);
rr_replace_reg (PATTERN (VARRAY_RTX (*uid_ruid, du_idx)), reg_use,
new_reg, SOURCE, VARRAY_RTX (*uid_ruid, du_idx),
&status);
death_note = find_reg_note (VARRAY_RTX (*uid_ruid, du_idx),
REG_DEAD, reg_use);
if (death_note)
{
REG_NOTES (VARRAY_RTX (*uid_ruid, du_idx))
= gen_rtx_EXPR_LIST (REG_DEAD, new_reg,
REG_NOTES (VARRAY_RTX (*uid_ruid,
du_idx)));
remove_note (VARRAY_RTX (*uid_ruid, du_idx),
find_reg_note (VARRAY_RTX (*uid_ruid, du_idx),
REG_DEAD, reg_use));
}
}
/* This insn may contain shared rtl replaced in the previous iteration.
Treat this equivalent to the rr_replace_reg case. */
if (TEST_BIT (du->uses[r], du_idx))
{
last_replaced_insn = du_idx;
SET_BIT (du->uses[avail_reg], du_idx);
RESET_BIT (du->uses[r], du_idx);
if (!status)
return status;
}
if (TEST_BIT (du->defs[r], du_idx))
break;
}
/* Add REG_DEAD note for replaced register at last use. */
if (last_replaced_insn)
{
new_reg = regno_use_in (avail_reg,
PATTERN (VARRAY_RTX (*uid_ruid,
last_replaced_insn)));
if (new_reg
&& ! find_reg_note (VARRAY_RTX (*uid_ruid, last_replaced_insn),
REG_DEAD, new_reg))
{
REG_NOTES (VARRAY_RTX (*uid_ruid, last_replaced_insn))
= gen_rtx_EXPR_LIST (REG_DEAD, new_reg,
REG_NOTES (VARRAY_RTX (*uid_ruid,
last_replaced_insn)));
remove_note (VARRAY_RTX (*uid_ruid, last_replaced_insn),
find_reg_note (VARRAY_RTX (*uid_ruid, last_replaced_insn),
REG_DEAD, reg_use));
}
}
return status;
}
/* Try to replace REG_USE in X with REG_SUB if INSN has a REPLACE_TYPE.
STATUS is zero if the resulting pattern is not valid. */
static rtx
rr_replace_reg (x, reg_use, reg_sub, replace_type, insn, status)
rtx x;
rtx reg_use;
rtx reg_sub;
int replace_type;
rtx insn;
int *status;
{
enum rtx_code code;
int i;
const char *fmt;
int n;
if (x == 0)
return x;
code = GET_CODE (x);
switch (code)
{
case REG:
if (REGNO (x) == REGNO (reg_use))
{
if (GET_MODE (x) == GET_MODE (reg_use))
return reg_sub;
else
return gen_rtx_REG (GET_MODE (x), REGNO (reg_sub));
}
return x;
case SET:
if (replace_type == DESTINATION)
SET_DEST (x) = rr_replace_reg (SET_DEST (x), reg_use, reg_sub,
replace_type, insn, status);
else if (replace_type == SOURCE)
{
unsigned int dest_subregno;
int had_subreg = GET_CODE (SET_DEST (x)) == SUBREG;
if (had_subreg)
dest_subregno = REGNO (XEXP (SET_DEST (x), 0));
SET_SRC (x) = rr_replace_reg (SET_SRC (x), reg_use, reg_sub,
replace_type, insn, status);
/* If the replacement register is not part of the source
then it may be part of a source mem operand. */
if (GET_CODE (SET_DEST (x)) == MEM
|| GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
|| GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
|| GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
SET_DEST (x) = rr_replace_reg (SET_DEST (x), reg_use, reg_sub,
replace_type, insn, status);
/* Shared rtl sanity check. */
if (had_subreg && dest_subregno != REGNO (XEXP (SET_DEST (x), 0)))
{
*status = 0;
return x;
}
}
n = recog_memoized (insn);
if (n >= 0)
{
int id;
extract_insn (insn);
/* Any MATCH_DUP's which are REGs must still match */
for (id = insn_data[n].n_dups - 1; id >= 0; id--)
{
int opno = recog_data.dup_num[id];
if (GET_CODE (*recog_data.dup_loc[id]) == REG
&& GET_CODE (*recog_data.operand_loc[opno]) == REG
&& (REGNO (*recog_data.dup_loc[id])
!= REGNO (*recog_data.operand_loc[opno])))
*status = 0;
}
if (!constrain_operands (1))
{
*status = 0;
validate_replace_rtx (reg_sub, reg_use, insn);
}
}
else
*status = 0;
return x;
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
XEXP (x, i) = rr_replace_reg (XEXP (x, i), reg_use, reg_sub,
replace_type, insn, status);
if (fmt[i] == 'E')
{
register int xv;
for (xv = 0; xv < XVECLEN (x, i); xv++)
{
XVECEXP (x, i, xv) = rr_replace_reg (XVECEXP (x, i, xv), reg_use,
reg_sub, replace_type, insn,
status);
n = recog_memoized (insn);
if (n >= 0)
{
extract_insn (insn);
if (!constrain_operands (1))
{
*status = 0;
validate_replace_rtx (reg_sub, reg_use, insn);
}
}
else
*status = 0;
}
}
}
return x;
}
/* Can REGNO in INSN be considered for renaming, given def INUM in d/u
chain DU? */
static int
consider_def (insn, regno, du, inum)
rtx insn;
int regno;
def_uses *du ATTRIBUTE_UNUSED;
int inum ATTRIBUTE_UNUSED;
{
/* Don't rename windowed registers across a call */
#ifdef INCOMING_REGNO
if (TEST_BIT (du->require_call_save_reg, inum)
&& INCOMING_REGNO (regno) != regno)
return 0;
#endif
/* Don't consider conditional moves. Predicate architectures may
use two complementary conditional moves and the regno shouldn't change */
if (condmove_p (insn))
return 0;
/* Don't rename call used registers across a call */
if (!(GET_CODE (insn) == CALL_INSN
&& TEST_HARD_REG_BIT (call_used_reg_set, regno)))
return 1;
else
return 0;
}
/* Can the use of REGNO in INSN of block USE_BLOCK be considered for renaming
for a def in def_block? */
static int
consider_use (insn, regno, def_block, use_block)
rtx insn;
int regno;
int def_block;
int use_block;
{
rtx reg_use;
edge e;
basic_block ub = BASIC_BLOCK (use_block);
if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
return 0;
/* If a use's basic block is different than the def's basic block,
then insure another predecessor does not also define this register */
if (def_block != use_block)
for (e = ub->pred; e; e = e->pred_next)
if (e->src->index != def_block
&& e->src->index != -1
&& REGNO_REG_SET_P (BASIC_BLOCK (e->src->index)->global_live_at_end,
regno))
return 0;
/* Don't consider conditional moves. Predicate architectures may
use two complementary conditional moves and the regno shouldn't change */
if (condmove_p (insn))
return 0;
reg_use = regno_first_use_in (regno, PATTERN (insn));
if (reg_use)
{
/* Don't consider multi-reg values. */
if (HARD_REGNO_NREGS (regno, GET_MODE (reg_use)) != 1
&& GET_MODE (reg_use) != CCmode)
return 0;
/* Don't consider register if the only use is in a USE */
return ! reg_mentioned_p (gen_rtx_USE (VOIDmode, reg_use),
PATTERN (insn));
}
else
return 0;
}
/* Can REG_USE be replaced by regno AVAIL_REG if it is in AVAIL_REGS
and it is in regclass RC, given insn INUM of def/use chain DU? */
static int
consider_available (reg_use, avail_reg, avail_regs, rc, du, inum)
rtx reg_use;
int avail_reg;
HARD_REG_SET *avail_regs;
int rc;
def_uses *du;
int inum;
{
if (!TEST_HARD_REG_BIT (*avail_regs, avail_reg))
return 0;
if (fixed_regs[avail_reg])
return 0;
#ifdef HARD_REGNO_RENAME_OK
if (!HARD_REGNO_RENAME_OK (REGNO (reg_use), avail_reg))
return 0;
#endif
/* Don't consider windowed leaf registers which will be renamed by
leaf_renumber_regs */
#ifdef LEAF_REG_REMAP
if (current_function_uses_only_leaf_regs)
if (LEAF_REG_REMAP (avail_reg) < 0)
return 0;
#endif
/* A register is considered available if it is available at the beginning of
the basic block. We may want to refine this to when a register becomes
available within the block. We don't consider multi-reg values. */
/* ??? Consider a representation that would allow multi-reg support? */
if (!TEST_HARD_REG_BIT (reg_class_contents[(enum reg_class) rc], avail_reg)
|| !HARD_REGNO_MODE_OK (avail_reg, GET_MODE (reg_use))
|| (HARD_REGNO_NREGS (avail_reg, GET_MODE (reg_use)) != 1
&& GET_MODE (reg_use) != CCmode)
|| (call_fixed_regs[avail_reg]
#ifdef HARD_REGNO_RENAME_OK
&& !HARD_REGNO_RENAME_OK (REGNO (reg_use), avail_reg)
#endif
)
|| (TEST_BIT (du->require_call_save_reg, inum)
&& (call_used_regs[avail_reg] || call_used_regs[REGNO (reg_use)])))
return 0;
/* If register is a callee-saved register it must be saved in the frame.
call saved registers can not be added to regs_ever_live after reload,
as it would invalidate most elimination offsets */
return regs_ever_live[avail_reg] || call_used_regs[avail_reg];
}
/* Return 1 if INSN is a conditional move */
static int
condmove_p (insn)
rtx insn;
{
return (GET_CODE (insn) == INSN
&& GET_CODE (PATTERN (insn)) == SET
&& GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE);
}
/* Searches X for the first reference to REGNO, returning the rtx of the
reference found if any. Otherwise, returns NULL_RTX. */
static rtx
regno_first_use_in (regno, x)
unsigned int regno;
rtx x;
{
register const char *fmt;
int i, j;
rtx tem;
if (GET_CODE (x) == REG && REGNO (x) == regno)
return x;
fmt = GET_RTX_FORMAT (GET_CODE (x));
for (i = 0; i <= GET_RTX_LENGTH (GET_CODE (x)) - 1; i++)
{
if (fmt[i] == 'e')
{
if ((tem = regno_first_use_in (regno, XEXP (x, i))))
return tem;
}
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
if ((tem = regno_first_use_in (regno, XVECEXP (x, i, j))))
return tem;
}
return 0;
}
/* Dump def/use chain DU to RTL_DUMP_FILE, given insns in UID_RUID and
which regs are live at end, GLOBAL_LIVE_AT_END */
static void
dump_def_use_chain (global_live_at_end, du, uid_ruid)
HARD_REG_SET *global_live_at_end;
def_uses *du;
varray_type *uid_ruid;
{
unsigned int r;
int inum;
for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
{
int set = 0;
for (inum = 0; inum <= du->high_bound; inum++)
{
rtx insn = VARRAY_RTX (*uid_ruid, inum);
#if 0
if (!insn
|| GET_RTX_CLASS (GET_CODE
(insn)) != 'i')
continue;
reg_use = regno_first_use_in (r, PATTERN (insn));
if (!reg_use)
continue;
#endif
if (!set && (TEST_BIT (du->defs[r], inum)
|| TEST_BIT (du->uses[r], inum)))
{
fprintf (rtl_dump_file, "Register %s: ", reg_names[r]);
if (fixed_regs[r])
fprintf (rtl_dump_file, "Fixed ");
else if (call_fixed_regs[r])
fprintf (rtl_dump_file, "Call Fixed ");
if (TEST_HARD_REG_BIT (*global_live_at_end, r))
fprintf (rtl_dump_file, "Live at Exit ");
set = 1;
}
if (TEST_BIT (du->defs[r], inum))
fprintf (rtl_dump_file, "=%d ", INSN_UID (insn));
if (TEST_BIT (du->uses[r], inum))
fprintf (rtl_dump_file, "%d ", INSN_UID (insn));
}
if (set)
fprintf (rtl_dump_file, "\n");
}
}
/* Dump info for extended basic block EBB having root EB */
static void
dump_ext_bb_info (eb, ebb)
int eb;
ext_basic_blocks *ebb;
{
int b;
int have_ebb = 0;
for (b = 0; b < n_basic_blocks; b++)
{
if (TEST_BIT (ebb->basic_block[eb], b))
{
if (!have_ebb)
{
#ifndef RENAME_EXTENDED_BLOCKS
fprintf (rtl_dump_file, "\nBasic block %d: ", b);
#else
fprintf (rtl_dump_file, "\nExtended basic block %d: ", b);
#endif
have_ebb = 1;
}
fprintf (rtl_dump_file, "%d ", b);
}
if (TEST_BIT (ebb->exit[eb], b))
fprintf (rtl_dump_file, "(exit) ");
}
if (have_ebb)
fprintf (rtl_dump_file, "\n");
}
/* Initialize EBB with extended basic block info if RENAME_EXTENDED_BLOCKS is
defined. Otherwise just use basic blocks */
static void
find_ext_basic_blocks (ebb)
ext_basic_blocks *ebb;
{
sbitmap bb_processed;
int b;
bb_processed = sbitmap_alloc (n_basic_blocks);
sbitmap_zero (bb_processed);
#ifndef RENAME_EXTENDED_BLOCKS
for (b = 0; b < n_basic_blocks; b++)
{
basic_block bb = BASIC_BLOCK (b);
SET_BIT (ebb->basic_block[bb->index], bb->index);
}
#else
for (b = 0; b < n_basic_blocks; b++)
{
basic_block bb = BASIC_BLOCK (b);
if (!TEST_BIT (bb_processed, b))
{
find_one_ext_basic_block (bb->index, bb, &bb_processed, ebb);
}
}
#endif
sbitmap_free (bb_processed);
}
/* Find one extended basic block EBB having root ENTRY containing block
BB */
static void
find_one_ext_basic_block (entry, bb, bb_processed, ebb)
int entry;
basic_block bb;
sbitmap *bb_processed;
ext_basic_blocks *ebb;
{
edge e;
if (!TEST_BIT (*bb_processed, bb->index))
{
SET_BIT (ebb->basic_block[entry], bb->index);
SET_BIT (*bb_processed, bb->index);
}
for (e = bb->succ; e; e = e->succ_next)
if (!TEST_BIT (*bb_processed, e->dest->index))
{
if (!e->dest->pred->pred_next
&& (!TEST_BIT (*bb_processed, e->dest->index)))
find_one_ext_basic_block (entry, e->dest, bb_processed, ebb);
else
SET_BIT (ebb->exit[entry], bb->index);
}
}
/* Find the register class for register REG_USE having TYPE (DESTINATION or
SOURCE) in INSN. Use DEFAULT_CLASS if we cannot determine a class. */
static enum reg_class
get_reg_class (insn, reg_use, type, default_class)
rtx insn;
rtx reg_use;
int type;
enum reg_class default_class;
{
int alt, id = 0;
extract_insn (insn);
constrain_operands (1);
alt = which_alternative;
preprocess_constraints ();
if (type == DESTINATION)
{
for (id = 0; id < recog_data.n_operands; id++)
if (rtx_equal_p (recog_data.operand[id], reg_use))
break;
}
else if (type == SOURCE)
for (id = recog_data.n_operands - 1; id >= 0; id--)
if (rtx_equal_p (recog_data.operand[id], reg_use))
break;
if (id == -1 || id == recog_data.n_operands)
return default_class;
return recog_op_alt[id][alt].class;
}