/* If-conversion support.
- Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
- This file is part of GNU CC.
+ This file is part of GCC.
- GNU CC is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
+ GCC is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
- GNU CC is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
+ GCC is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
You should have received a copy of the GNU General Public License
- along with GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with GCC; see the file COPYING. If not, write to the Free
+ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+ 02111-1307, USA. */
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "rtl.h"
#include "regs.h"
#include "flags.h"
#include "insn-config.h"
#include "recog.h"
+#include "except.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "expr.h"
-#include "optabs.h"
#include "real.h"
#include "output.h"
#include "toplev.h"
/* # of basic blocks that were removed. */
static int num_removed_blocks;
+/* Whether conditional execution changes were made. */
+static int cond_exec_changed_p;
+
/* True if life data ok at present. */
static bool life_data_ok;
/* The post-dominator relation on the original block numbers. */
-static sbitmap *post_dominators;
+static dominance_info post_dominators;
/* Forward references. */
static int count_bb_insns PARAMS ((basic_block));
static rtx first_active_insn PARAMS ((basic_block));
-static int last_active_insn_p PARAMS ((basic_block, rtx));
+static rtx last_active_insn PARAMS ((basic_block, int));
static int seq_contains_jump PARAMS ((rtx));
-
-static int cond_exec_process_insns PARAMS ((rtx, rtx, rtx, rtx, int));
+static basic_block block_fallthru PARAMS ((basic_block));
+static int cond_exec_process_insns PARAMS ((ce_if_block_t *,
+ rtx, rtx, rtx, rtx, int));
static rtx cond_exec_get_condition PARAMS ((rtx));
-static int cond_exec_process_if_block PARAMS ((basic_block, basic_block,
- basic_block, basic_block));
-
+static int cond_exec_process_if_block PARAMS ((ce_if_block_t *, int));
static rtx noce_get_condition PARAMS ((rtx, rtx *));
static int noce_operand_ok PARAMS ((rtx));
-static int noce_process_if_block PARAMS ((basic_block, basic_block,
- basic_block, basic_block));
-
-static int process_if_block PARAMS ((basic_block, basic_block,
- basic_block, basic_block));
-static void merge_if_block PARAMS ((basic_block, basic_block,
- basic_block, basic_block));
-
-static int find_if_header PARAMS ((basic_block));
-static int find_if_block PARAMS ((basic_block, edge, edge));
+static int noce_process_if_block PARAMS ((ce_if_block_t *));
+static int process_if_block PARAMS ((ce_if_block_t *));
+static void merge_if_block PARAMS ((ce_if_block_t *));
+static int find_cond_trap PARAMS ((basic_block, edge, edge));
+static basic_block find_if_header PARAMS ((basic_block, int));
+static int block_jumps_and_fallthru_p PARAMS ((basic_block, basic_block));
+static int find_if_block PARAMS ((ce_if_block_t *));
static int find_if_case_1 PARAMS ((basic_block, edge, edge));
static int find_if_case_2 PARAMS ((basic_block, edge, edge));
-static int find_cond_trap PARAMS ((basic_block, edge, edge));
static int find_memory PARAMS ((rtx *, void *));
static int dead_or_predicable PARAMS ((basic_block, basic_block,
basic_block, basic_block, int));
static void noce_emit_move_insn PARAMS ((rtx, rtx));
-\f
-/* Abuse the basic_block AUX field to store the original block index,
- as well as a flag indicating that the block should be rescaned for
- life analysis. */
-
-#define SET_ORIG_INDEX(BB,I) ((BB)->aux = (void *)((size_t)(I) << 1))
-#define ORIG_INDEX(BB) ((size_t)(BB)->aux >> 1)
-#define SET_UPDATE_LIFE(BB) ((BB)->aux = (void *)((size_t)(BB)->aux | 1))
-#define UPDATE_LIFE(BB) ((size_t)(BB)->aux & 1)
-
+static rtx block_has_only_trap PARAMS ((basic_block));
\f
/* Count the number of non-jump active insns in BB. */
return insn;
}
-/* Return true if INSN is the last active non-jump insn in BB. */
+/* Return the last non-jump active (non-jump) insn in the basic block. */
-static int
-last_active_insn_p (bb, insn)
+static rtx
+last_active_insn (bb, skip_use_p)
basic_block bb;
- rtx insn;
+ int skip_use_p;
{
- do
+ rtx insn = bb->end;
+ rtx head = bb->head;
+
+ while (GET_CODE (insn) == NOTE
+ || GET_CODE (insn) == JUMP_INSN
+ || (skip_use_p
+ && GET_CODE (insn) == INSN
+ && GET_CODE (PATTERN (insn)) == USE))
{
- if (insn == bb->end)
- return TRUE;
- insn = NEXT_INSN (insn);
+ if (insn == head)
+ return NULL_RTX;
+ insn = PREV_INSN (insn);
}
- while (GET_CODE (insn) == NOTE);
- return GET_CODE (insn) == JUMP_INSN;
+ if (GET_CODE (insn) == CODE_LABEL)
+ return NULL_RTX;
+
+ return insn;
}
/* It is possible, especially when having dealt with multi-word
}
return 0;
}
+
+static basic_block
+block_fallthru (bb)
+ basic_block bb;
+{
+ edge e;
+
+ for (e = bb->succ;
+ e != NULL_EDGE && (e->flags & EDGE_FALLTHRU) == 0;
+ e = e->succ_next)
+ ;
+
+ return (e) ? e->dest : NULL_BLOCK;
+}
\f
/* Go through a bunch of insns, converting them to conditional
execution format if possible. Return TRUE if all of the non-note
insns were processed. */
static int
-cond_exec_process_insns (start, end, test, prob_val, mod_ok)
+cond_exec_process_insns (ce_info, start, end, test, prob_val, mod_ok)
+ ce_if_block_t *ce_info ATTRIBUTE_UNUSED; /* if block information */
rtx start; /* first insn to look at */
rtx end; /* last insn to look at */
rtx test; /* conditional execution test */
{
int must_be_last = FALSE;
rtx insn;
+ rtx xtest;
rtx pattern;
+ if (!start || !end)
+ return FALSE;
+
for (insn = start; ; insn = NEXT_INSN (insn))
{
if (GET_CODE (insn) == NOTE)
/* Now build the conditional form of the instruction. */
pattern = PATTERN (insn);
+ xtest = copy_rtx (test);
+
+ /* If this is already a COND_EXEC, rewrite the test to be an AND of the
+ two conditions. */
+ if (GET_CODE (pattern) == COND_EXEC)
+ {
+ if (GET_MODE (xtest) != GET_MODE (COND_EXEC_TEST (pattern)))
+ return FALSE;
+
+ xtest = gen_rtx_AND (GET_MODE (xtest), xtest,
+ COND_EXEC_TEST (pattern));
+ pattern = COND_EXEC_CODE (pattern);
+ }
+
+ pattern = gen_rtx_COND_EXEC (VOIDmode, xtest, pattern);
/* If the machine needs to modify the insn being conditionally executed,
say for example to force a constant integer operand into a temp
register, do so here. */
#ifdef IFCVT_MODIFY_INSN
- IFCVT_MODIFY_INSN (pattern, insn);
+ IFCVT_MODIFY_INSN (ce_info, pattern, insn);
if (! pattern)
return FALSE;
#endif
- validate_change (insn, &PATTERN (insn),
- gen_rtx_COND_EXEC (VOIDmode, copy_rtx (test),
- pattern), 1);
+ validate_change (insn, &PATTERN (insn), pattern, 1);
if (GET_CODE (insn) == CALL_INSN && prob_val)
validate_change (insn, ®_NOTES (insn),
/* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
to conditional execution. Return TRUE if we were successful at
- converting the the block. */
+ converting the block. */
static int
-cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb)
- basic_block test_bb; /* Basic block test is in */
- basic_block then_bb; /* Basic block for THEN block */
- basic_block else_bb; /* Basic block for ELSE block */
- basic_block join_bb; /* Basic block the join label is in */
+cond_exec_process_if_block (ce_info, do_multiple_p)
+ ce_if_block_t * ce_info; /* if block information */
+ int do_multiple_p; /* != 0 if we should handle && and || blocks */
{
+ basic_block test_bb = ce_info->test_bb; /* last test block */
+ basic_block then_bb = ce_info->then_bb; /* THEN */
+ basic_block else_bb = ce_info->else_bb; /* ELSE or NULL */
rtx test_expr; /* expression in IF_THEN_ELSE that is tested */
rtx then_start; /* first insn in THEN block */
rtx then_end; /* last insn + 1 in THEN block */
int n_insns;
enum rtx_code false_code;
+ /* If test is comprised of && or || elements, and we've failed at handling
+ all of them together, just use the last test if it is the special case of
+ && elements without an ELSE block. */
+ if (!do_multiple_p && ce_info->num_multiple_test_blocks)
+ {
+ if (else_bb || ! ce_info->and_and_p)
+ return FALSE;
+
+ ce_info->test_bb = test_bb = ce_info->last_test_bb;
+ ce_info->num_multiple_test_blocks = 0;
+ ce_info->num_and_and_blocks = 0;
+ ce_info->num_or_or_blocks = 0;
+ }
+
/* Find the conditional jump to the ELSE or JOIN part, and isolate
the test. */
test_expr = cond_exec_get_condition (test_bb->end);
/* If the conditional jump is more than just a conditional jump,
then we can not do conditional execution conversion on this block. */
- if (!onlyjump_p (test_bb->end))
+ if (! onlyjump_p (test_bb->end))
return FALSE;
- /* Collect the bounds of where we're to search. */
-
- then_start = then_bb->head;
- then_end = then_bb->end;
-
- /* Skip a label heading THEN block. */
- if (GET_CODE (then_start) == CODE_LABEL)
- then_start = NEXT_INSN (then_start);
-
- /* Skip a (use (const_int 0)) or branch as the final insn. */
- if (GET_CODE (then_end) == INSN
- && GET_CODE (PATTERN (then_end)) == USE
- && GET_CODE (XEXP (PATTERN (then_end), 0)) == CONST_INT)
- then_end = PREV_INSN (then_end);
- else if (GET_CODE (then_end) == JUMP_INSN)
- then_end = PREV_INSN (then_end);
+ /* Collect the bounds of where we're to search, skipping any labels, jumps
+ and notes at the beginning and end of the block. Then count the total
+ number of insns and see if it is small enough to convert. */
+ then_start = first_active_insn (then_bb);
+ then_end = last_active_insn (then_bb, TRUE);
+ n_insns = ce_info->num_then_insns = count_bb_insns (then_bb);
+ max = MAX_CONDITIONAL_EXECUTE;
if (else_bb)
{
- /* Skip the ELSE block's label. */
- else_start = NEXT_INSN (else_bb->head);
- else_end = else_bb->end;
-
- /* Skip a (use (const_int 0)) or branch as the final insn. */
- if (GET_CODE (else_end) == INSN
- && GET_CODE (PATTERN (else_end)) == USE
- && GET_CODE (XEXP (PATTERN (else_end), 0)) == CONST_INT)
- else_end = PREV_INSN (else_end);
- else if (GET_CODE (else_end) == JUMP_INSN)
- else_end = PREV_INSN (else_end);
+ max *= 2;
+ else_start = first_active_insn (else_bb);
+ else_end = last_active_insn (else_bb, TRUE);
+ n_insns += ce_info->num_else_insns = count_bb_insns (else_bb);
}
- /* How many instructions should we convert in total? */
- n_insns = 0;
- if (else_bb)
- {
- max = 2 * MAX_CONDITIONAL_EXECUTE;
- n_insns = count_bb_insns (else_bb);
- }
- else
- max = MAX_CONDITIONAL_EXECUTE;
- n_insns += count_bb_insns (then_bb);
if (n_insns > max)
return FALSE;
#ifdef IFCVT_MODIFY_TESTS
/* If the machine description needs to modify the tests, such as setting a
conditional execution register from a comparison, it can do so here. */
- IFCVT_MODIFY_TESTS (true_expr, false_expr, test_bb, then_bb, else_bb,
- join_bb);
+ IFCVT_MODIFY_TESTS (ce_info, true_expr, false_expr);
/* See if the conversion failed */
if (!true_expr || !false_expr)
else
false_prob_val = NULL_RTX;
+ /* If we have && or || tests, do them here. These tests are in the adjacent
+ blocks after the first block containing the test. */
+ if (ce_info->num_multiple_test_blocks > 0)
+ {
+ basic_block bb = test_bb;
+ basic_block last_test_bb = ce_info->last_test_bb;
+
+ if (! false_expr)
+ goto fail;
+
+ do
+ {
+ rtx start, end;
+ rtx t, f;
+
+ bb = block_fallthru (bb);
+ start = first_active_insn (bb);
+ end = last_active_insn (bb, TRUE);
+ if (start
+ && ! cond_exec_process_insns (ce_info, start, end, false_expr,
+ false_prob_val, FALSE))
+ goto fail;
+
+ /* If the conditional jump is more than just a conditional jump, then
+ we can not do conditional execution conversion on this block. */
+ if (! onlyjump_p (bb->end))
+ goto fail;
+
+ /* Find the conditional jump and isolate the test. */
+ t = cond_exec_get_condition (bb->end);
+ if (! t)
+ goto fail;
+
+ f = gen_rtx_fmt_ee (reverse_condition (GET_CODE (t)),
+ GET_MODE (t),
+ XEXP (t, 0),
+ XEXP (t, 1));
+
+ if (ce_info->and_and_p)
+ {
+ t = gen_rtx_AND (GET_MODE (t), true_expr, t);
+ f = gen_rtx_IOR (GET_MODE (t), false_expr, f);
+ }
+ else
+ {
+ t = gen_rtx_IOR (GET_MODE (t), true_expr, t);
+ f = gen_rtx_AND (GET_MODE (t), false_expr, f);
+ }
+
+ /* If the machine description needs to modify the tests, such as
+ setting a conditional execution register from a comparison, it can
+ do so here. */
+#ifdef IFCVT_MODIFY_MULTIPLE_TESTS
+ IFCVT_MODIFY_MULTIPLE_TESTS (ce_info, bb, t, f);
+
+ /* See if the conversion failed */
+ if (!t || !f)
+ goto fail;
+#endif
+
+ true_expr = t;
+ false_expr = f;
+ }
+ while (bb != last_test_bb);
+ }
+
/* For IF-THEN-ELSE blocks, we don't allow modifications of the test
on then THEN block. */
then_mod_ok = (else_bb == NULL_BLOCK);
if (then_end
&& (! false_expr
- || ! cond_exec_process_insns (then_start, then_end, false_expr,
- false_prob_val, then_mod_ok)))
+ || ! cond_exec_process_insns (ce_info, then_start, then_end,
+ false_expr, false_prob_val,
+ then_mod_ok)))
goto fail;
- if (else_bb
- && ! cond_exec_process_insns (else_start, else_end,
+ if (else_bb && else_end
+ && ! cond_exec_process_insns (ce_info, else_start, else_end,
true_expr, true_prob_val, TRUE))
goto fail;
+ /* If we cannot apply the changes, fail. Do not go through the normal fail
+ processing, since apply_change_group will call cancel_changes. */
if (! apply_change_group ())
- return FALSE;
+ {
+#ifdef IFCVT_MODIFY_CANCEL
+ /* Cancel any machine dependent changes. */
+ IFCVT_MODIFY_CANCEL (ce_info);
+#endif
+ return FALSE;
+ }
#ifdef IFCVT_MODIFY_FINAL
/* Do any machine dependent final modifications */
- IFCVT_MODIFY_FINAL (test_bb, then_bb, else_bb, join_bb);
+ IFCVT_MODIFY_FINAL (ce_info);
#endif
/* Conversion succeeded. */
n_insns, (n_insns == 1) ? " was" : "s were");
/* Merge the blocks! */
- merge_if_block (test_bb, then_bb, else_bb, join_bb);
+ merge_if_block (ce_info);
+ cond_exec_changed_p = TRUE;
return TRUE;
fail:
#ifdef IFCVT_MODIFY_CANCEL
/* Cancel any machine dependent changes. */
- IFCVT_MODIFY_CANCEL (test_bb, then_bb, else_bb, join_bb);
+ IFCVT_MODIFY_CANCEL (ce_info);
#endif
cancel_changes (0);
{
tmp = get_insns ();
end_sequence ();
- emit_insns (tmp);
+ emit_insn (tmp);
if_info->cond_earliest = if_info->jump;
|| code == GEU || code == GTU), normalize);
}
-/* Emit instruction to move a rtx into STRICT_LOW_PART. */
+/* Emit instruction to move an rtx into STRICT_LOW_PART. */
static void
noce_emit_move_insn (x, y)
rtx x, y;
outmode = GET_MODE (outer);
inmode = GET_MODE (inner);
bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
- store_bit_field (inner, GET_MODE_BITSIZE (outmode),
- bitpos, outmode, y, GET_MODE_BITSIZE (inmode),
+ store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos, outmode, y,
GET_MODE_BITSIZE (inmode));
}
seq = get_insns ();
end_sequence ();
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_scope (seq, if_info->jump, INSN_SCOPE (if_info->insn_a));
return TRUE;
}
mode = GET_MODE (if_info->x);
ifalse = INTVAL (if_info->a);
itrue = INTVAL (if_info->b);
+
+ /* Make sure we can represent the difference between the two values. */
+ if ((itrue - ifalse > 0)
+ != ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue))
+ return FALSE;
+
diff = trunc_int_for_mode (itrue - ifalse, mode);
can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)
=> x = 3 + (test == 0); */
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
{
- target = expand_binop (mode,
- (diff == STORE_FLAG_VALUE
- ? add_optab : sub_optab),
- GEN_INT (ifalse), target, if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode,
+ (diff == STORE_FLAG_VALUE
+ ? PLUS : MINUS),
+ GEN_INT (ifalse), target, if_info->x, 0,
+ OPTAB_WIDEN);
}
/* if (test) x = 8; else x = 0;
=> x = (test != 0) << 3; */
else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0)
{
- target = expand_binop (mode, ashl_optab,
- target, GEN_INT (tmp), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, ASHIFT,
+ target, GEN_INT (tmp), if_info->x, 0,
+ OPTAB_WIDEN);
}
/* if (test) x = -1; else x = b;
=> x = -(test != 0) | b; */
else if (itrue == -1)
{
- target = expand_binop (mode, ior_optab,
- target, GEN_INT (ifalse), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, IOR,
+ target, GEN_INT (ifalse), if_info->x, 0,
+ OPTAB_WIDEN);
}
/* if (test) x = a; else x = b;
=> x = (-(test != 0) & (b - a)) + a; */
else
{
- target = expand_binop (mode, and_optab,
- target, GEN_INT (diff), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, AND,
+ target, GEN_INT (diff), if_info->x, 0,
+ OPTAB_WIDEN);
if (target)
- target = expand_binop (mode, add_optab,
- target, GEN_INT (ifalse), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, PLUS,
+ target, GEN_INT (ifalse),
+ if_info->x, 0, OPTAB_WIDEN);
}
if (! target)
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_scope (seq, if_info->jump, INSN_SCOPE (if_info->insn_a));
return TRUE;
}
1, normalize);
if (target)
- target = expand_binop (GET_MODE (if_info->x),
- subtract ? sub_optab : add_optab,
- if_info->x, target, if_info->x, 0, OPTAB_WIDEN);
+ target = expand_simple_binop (GET_MODE (if_info->x),
+ subtract ? MINUS : PLUS,
+ if_info->x, target, if_info->x,
+ 0, OPTAB_WIDEN);
if (target)
{
if (target != if_info->x)
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_scope (seq, if_info->jump,
+ INSN_SCOPE (if_info->insn_a));
return TRUE;
}
gen_reg_rtx (GET_MODE (if_info->x)),
reversep, -1);
if (target)
- target = expand_binop (GET_MODE (if_info->x), and_optab,
- if_info->x, target, if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (GET_MODE (if_info->x), AND,
+ if_info->x, target, if_info->x, 0,
+ OPTAB_WIDEN);
if (target)
{
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_scope (seq, if_info->jump,
+ INSN_SCOPE (if_info->insn_a));
return TRUE;
}
{
tmp = get_insns ();
end_sequence ();
- emit_insns (tmp);
+ emit_insn (tmp);
return x;
}
seq = get_insns ();
end_sequence ();
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_scope (seq, if_info->jump,
+ INSN_SCOPE (if_info->insn_a));
return TRUE;
}
else
MEM_SCALAR_P (tmp) = 1;
if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a));
+ set_mem_align (tmp,
+ MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
noce_emit_move_insn (if_info->x, tmp);
}
tmp = get_insns ();
end_sequence ();
- emit_insns_before (tmp, if_info->cond_earliest);
+ emit_insn_before_scope (tmp, if_info->jump, INSN_SCOPE (if_info->insn_a));
return TRUE;
end_seq_and_fail:
/* X may not be mentioned in the range (cond_earliest, jump]. */
for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn))
- if (INSN_P (insn) && reg_mentioned_p (if_info->x, insn))
+ if (INSN_P (insn) && reg_overlap_mentioned_p (if_info->x, PATTERN (insn)))
return NULL;
/* A and B may not be modified in the range [cond_earliest, jump). */
struct noce_if_info *if_info;
{
rtx cond, earliest, target, seq;
- enum rtx_code code;
+ enum rtx_code code, op;
int unsignedp;
- optab op;
/* ??? Can't guarantee that expand_binop won't create pseudos. */
if (no_new_pseudos)
return FALSE;
- /* ??? Reject FP modes since we don't know how 0 vs -0 or NaNs
- will be resolved with an SMIN/SMAX. It wouldn't be too hard
+ /* ??? Reject modes with NaNs or signed zeros since we don't know how
+ they will be resolved with an SMIN/SMAX. It wouldn't be too hard
to get the target to tell us... */
- if (FLOAT_MODE_P (GET_MODE (if_info->x))
- && TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
- && ! flag_unsafe_math_optimizations)
+ if (HONOR_SIGNED_ZEROS (GET_MODE (if_info->x))
+ || HONOR_NANS (GET_MODE (if_info->x)))
return FALSE;
cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
case LE:
case UNLT:
case UNLE:
- op = smax_optab;
+ op = SMAX;
unsignedp = 0;
break;
case GT:
case GE:
case UNGT:
case UNGE:
- op = smin_optab;
+ op = SMIN;
unsignedp = 0;
break;
case LTU:
case LEU:
- op = umax_optab;
+ op = UMAX;
unsignedp = 1;
break;
case GTU:
case GEU:
- op = umin_optab;
+ op = UMIN;
unsignedp = 1;
break;
default:
start_sequence ();
- target = expand_binop (GET_MODE (if_info->x), op, if_info->a, if_info->b,
- if_info->x, unsignedp, OPTAB_WIDEN);
+ target = expand_simple_binop (GET_MODE (if_info->x), op,
+ if_info->a, if_info->b,
+ if_info->x, unsignedp, OPTAB_WIDEN);
if (! target)
{
end_sequence ();
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, earliest);
+ emit_insn_before_scope (seq, if_info->jump, INSN_SCOPE (if_info->insn_a));
if_info->cond = cond;
if_info->cond_earliest = earliest;
start_sequence ();
- target = expand_unop (GET_MODE (if_info->x), abs_optab, b, if_info->x, 0);
+ target = expand_simple_unop (GET_MODE (if_info->x), ABS, b, if_info->x, 0);
/* ??? It's a quandry whether cmove would be better here, especially
for integers. Perhaps combine will clean things up. */
if (target && negate)
- target = expand_unop (GET_MODE (target), neg_optab, target, if_info->x, 0);
+ target = expand_simple_unop (GET_MODE (target), NEG, target, if_info->x, 0);
if (! target)
{
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, earliest);
+ emit_insn_before_scope (seq, if_info->jump, INSN_SCOPE (if_info->insn_a));
if_info->cond = cond;
if_info->cond_earliest = earliest;
return TRUE;
}
-/* Look for the condition for the jump first. We'd prefer to avoid
- get_condition if we can -- it tries to look back for the contents
- of an original compare. On targets that use normal integers for
- comparisons, e.g. alpha, this is wasteful. */
+/* Similar to get_condition, only the resulting condition must be
+ valid at JUMP, instead of at EARLIEST. */
static rtx
noce_get_condition (jump, earliest)
rtx jump;
rtx *earliest;
{
- rtx cond;
- rtx set;
-
- /* If the condition variable is a register and is MODE_INT, accept it.
- Otherwise, fall back on get_condition. */
+ rtx cond, set, tmp, insn;
+ bool reverse;
if (! any_condjump_p (jump))
return NULL_RTX;
set = pc_set (jump);
+ /* If this branches to JUMP_LABEL when the condition is false,
+ reverse the condition. */
+ reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
+ && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump));
+
+ /* If the condition variable is a register and is MODE_INT, accept it. */
+
cond = XEXP (SET_SRC (set), 0);
- if (GET_CODE (XEXP (cond, 0)) == REG
- && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_INT)
+ tmp = XEXP (cond, 0);
+ if (REG_P (tmp) && GET_MODE_CLASS (GET_MODE (tmp)) == MODE_INT)
{
*earliest = jump;
- /* If this branches to JUMP_LABEL when the condition is false,
- reverse the condition. */
- if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
- && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump))
+ if (reverse)
cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
- GET_MODE (cond), XEXP (cond, 0),
- XEXP (cond, 1));
+ GET_MODE (cond), tmp, XEXP (cond, 1));
+ return cond;
}
- else
- cond = get_condition (jump, earliest);
- return cond;
+ /* Otherwise, fall back on canonicalize_condition to do the dirty
+ work of manipulating MODE_CC values and COMPARE rtx codes. */
+
+ tmp = canonicalize_condition (jump, cond, reverse, earliest, NULL_RTX);
+ if (!tmp)
+ return NULL_RTX;
+
+ /* We are going to insert code before JUMP, not before EARLIEST.
+ We must therefore be certain that the given condition is valid
+ at JUMP by virtue of not having been modified since. */
+ for (insn = *earliest; insn != jump; insn = NEXT_INSN (insn))
+ if (INSN_P (insn) && modified_in_p (tmp, insn))
+ break;
+ if (insn == jump)
+ return tmp;
+
+ /* The condition was modified. See if we can get a partial result
+ that doesn't follow all the reversals. Perhaps combine can fold
+ them together later. */
+ tmp = XEXP (tmp, 0);
+ if (!REG_P (tmp) || GET_MODE_CLASS (GET_MODE (tmp)) != MODE_INT)
+ return NULL_RTX;
+ tmp = canonicalize_condition (jump, cond, reverse, earliest, tmp);
+ if (!tmp)
+ return NULL_RTX;
+
+ /* For sanity's sake, re-validate the new result. */
+ for (insn = *earliest; insn != jump; insn = NEXT_INSN (insn))
+ if (INSN_P (insn) && modified_in_p (tmp, insn))
+ return NULL_RTX;
+
+ return tmp;
}
/* Return true if OP is ok for if-then-else processing. */
if (side_effects_p (op))
return FALSE;
- /* ??? Unfortuantely may_trap_p can't look at flag_trapping_math, due to
- being linked into the genfoo programs. This is probably a mistake.
- With finite operands, most fp operations don't trap. */
- if (!flag_trapping_math && FLOAT_MODE_P (GET_MODE (op)))
- switch (GET_CODE (op))
- {
- case DIV:
- case MOD:
- case UDIV:
- case UMOD:
- /* ??? This is kinda lame -- almost every target will have forced
- the constant into a register first. But given the expense of
- division, this is probably for the best. */
- return (CONSTANT_P (XEXP (op, 1))
- && XEXP (op, 1) != CONST0_RTX (GET_MODE (op))
- && ! may_trap_p (XEXP (op, 0)));
-
- default:
- switch (GET_RTX_CLASS (GET_CODE (op)))
- {
- case '1':
- return ! may_trap_p (XEXP (op, 0));
- case 'c':
- case '2':
- return ! may_trap_p (XEXP (op, 0)) && ! may_trap_p (XEXP (op, 1));
- }
- break;
- }
-
return ! may_trap_p (op);
}
/* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
without using conditional execution. Return TRUE if we were
- successful at converting the the block. */
+ successful at converting the block. */
static int
-noce_process_if_block (test_bb, then_bb, else_bb, join_bb)
- basic_block test_bb; /* Basic block test is in */
- basic_block then_bb; /* Basic block for THEN block */
- basic_block else_bb; /* Basic block for ELSE block */
- basic_block join_bb; /* Basic block the join label is in */
+noce_process_if_block (ce_info)
+ struct ce_if_block * ce_info;
{
+ basic_block test_bb = ce_info->test_bb; /* test block */
+ basic_block then_bb = ce_info->then_bb; /* THEN */
+ basic_block else_bb = ce_info->else_bb; /* ELSE or NULL */
+ struct noce_if_info if_info;
+ rtx insn_a, insn_b;
+ rtx set_a, set_b;
+ rtx orig_x, x, a, b;
+ rtx jump, cond;
+
/* We're looking for patterns of the form
(1) if (...) x = a; else x = b;
??? For future expansion, look for multiple X in such patterns. */
- struct noce_if_info if_info;
- rtx insn_a, insn_b;
- rtx set_a, set_b;
- rtx orig_x, x, a, b;
- rtx jump, cond, insn;
+ /* If test is comprised of && or || elements, don't handle it unless it is
+ the special case of && elements without an ELSE block. */
+ if (ce_info->num_multiple_test_blocks)
+ {
+ if (else_bb || ! ce_info->and_and_p)
+ return FALSE;
+
+ ce_info->test_bb = test_bb = ce_info->last_test_bb;
+ ce_info->num_multiple_test_blocks = 0;
+ ce_info->num_and_and_blocks = 0;
+ ce_info->num_or_or_blocks = 0;
+ }
/* If this is not a standard conditional jump, we can't parse it. */
jump = test_bb->end;
if (! cond)
return FALSE;
- /* If the conditional jump is more than just a conditional jump,
- then we can not do if-conversion on this block. */
+ /* If the conditional jump is more than just a conditional
+ jump, then we can not do if-conversion on this block. */
if (! onlyjump_p (jump))
return FALSE;
/* Look for one of the potential sets. */
insn_a = first_active_insn (then_bb);
if (! insn_a
- || ! last_active_insn_p (then_bb, insn_a)
+ || insn_a != last_active_insn (then_bb, FALSE)
|| (set_a = single_set (insn_a)) == NULL_RTX)
return FALSE;
{
insn_b = first_active_insn (else_bb);
if (! insn_b
- || ! last_active_insn_p (else_bb, insn_b)
+ || insn_b != last_active_insn (else_bb, FALSE)
|| (set_b = single_set (insn_b)) == NULL_RTX
|| ! rtx_equal_p (x, SET_DEST (set_b)))
return FALSE;
|| GET_CODE (insn_b) != INSN
|| (set_b = single_set (insn_b)) == NULL_RTX
|| ! rtx_equal_p (x, SET_DEST (set_b))
- || reg_mentioned_p (x, cond)
- || reg_mentioned_p (x, a)
- || reg_mentioned_p (x, SET_SRC (set_b)))
+ || reg_overlap_mentioned_p (x, cond)
+ || reg_overlap_mentioned_p (x, a)
+ || reg_overlap_mentioned_p (x, SET_SRC (set_b))
+ || modified_between_p (x, if_info.cond_earliest, NEXT_INSN (jump)))
insn_b = set_b = NULL_RTX;
}
b = (set_b ? SET_SRC (set_b) : x);
- /* X may not be mentioned in the range (cond_earliest, jump]. */
- for (insn = jump; insn != if_info.cond_earliest; insn = PREV_INSN (insn))
- if (INSN_P (insn) && reg_mentioned_p (x, insn))
- return FALSE;
-
- /* A and B may not be modified in the range [cond_earliest, jump). */
- for (insn = if_info.cond_earliest; insn != jump; insn = NEXT_INSN (insn))
- if (INSN_P (insn)
- && (modified_in_p (a, insn) || modified_in_p (b, insn)))
- return FALSE;
-
/* Only operate on register destinations, and even then avoid extending
the lifetime of hard registers on small register class machines. */
orig_x = x;
if (else_bb && insn_b == else_bb->end)
else_bb->end = PREV_INSN (insn_b);
- reorder_insns (insn_b, insn_b, PREV_INSN (if_info.cond_earliest));
+ reorder_insns (insn_b, insn_b, PREV_INSN (jump));
/* If there was a REG_EQUAL note, delete it since it may have been
true due to this insn being after a jump. */
success:
/* The original sets may now be killed. */
- if (insn_a == then_bb->end)
- then_bb->end = PREV_INSN (insn_a);
- flow_delete_insn (insn_a);
+ delete_insn (insn_a);
/* Several special cases here: First, we may have reused insn_b above,
in which case insn_b is now NULL. Second, we want to delete insn_b
the TEST block, it may in fact be loading data needed for the comparison.
We'll let life_analysis remove the insn if it's really dead. */
if (insn_b && else_bb)
- {
- if (insn_b == else_bb->end)
- else_bb->end = PREV_INSN (insn_b);
- flow_delete_insn (insn_b);
- }
+ delete_insn (insn_b);
- /* The new insns will have been inserted before cond_earliest. We should
- be able to remove the jump with impunity, but the condition itself may
- have been modified by gcse to be shared across basic blocks. */
- test_bb->end = PREV_INSN (jump);
- flow_delete_insn (jump);
+ /* The new insns will have been inserted immediately before the jump. We
+ should be able to remove the jump with impunity, but the condition itself
+ may have been modified by gcse to be shared across basic blocks. */
+ delete_insn (jump);
/* If we used a temporary, fix it up now. */
if (orig_x != x)
{
start_sequence ();
- noce_emit_move_insn (orig_x, x);
- insn_b = gen_sequence ();
+ noce_emit_move_insn (copy_rtx (orig_x), x);
+ insn_b = get_insns ();
end_sequence ();
- test_bb->end = emit_insn_after (insn_b, test_bb->end);
+ emit_insn_after_scope (insn_b, test_bb->end, INSN_SCOPE (insn_a));
}
/* Merge the blocks! */
- merge_if_block (test_bb, then_bb, else_bb, join_bb);
+ merge_if_block (ce_info);
return TRUE;
}
straight line code. Return true if successful. */
static int
-process_if_block (test_bb, then_bb, else_bb, join_bb)
- basic_block test_bb; /* Basic block test is in */
- basic_block then_bb; /* Basic block for THEN block */
- basic_block else_bb; /* Basic block for ELSE block */
- basic_block join_bb; /* Basic block the join label is in */
+process_if_block (ce_info)
+ struct ce_if_block * ce_info;
{
if (! reload_completed
- && noce_process_if_block (test_bb, then_bb, else_bb, join_bb))
+ && noce_process_if_block (ce_info))
return TRUE;
- if (HAVE_conditional_execution
- && reload_completed
- && cond_exec_process_if_block (test_bb, then_bb, else_bb, join_bb))
- return TRUE;
+ if (HAVE_conditional_execution && reload_completed)
+ {
+ /* If we have && and || tests, try to first handle combining the && and
+ || tests into the conditional code, and if that fails, go back and
+ handle it without the && and ||, which at present handles the && case
+ if there was no ELSE block. */
+ if (cond_exec_process_if_block (ce_info, TRUE))
+ return TRUE;
+
+ if (ce_info->num_multiple_test_blocks)
+ {
+ cancel_changes (0);
+
+ if (cond_exec_process_if_block (ce_info, FALSE))
+ return TRUE;
+ }
+ }
return FALSE;
}
/* Merge the blocks and mark for local life update. */
static void
-merge_if_block (test_bb, then_bb, else_bb, join_bb)
- basic_block test_bb; /* Basic block test is in */
- basic_block then_bb; /* Basic block for THEN block */
- basic_block else_bb; /* Basic block for ELSE block */
- basic_block join_bb; /* Basic block the join label is in */
+merge_if_block (ce_info)
+ struct ce_if_block * ce_info;
{
+ basic_block test_bb = ce_info->test_bb; /* last test block */
+ basic_block then_bb = ce_info->then_bb; /* THEN */
+ basic_block else_bb = ce_info->else_bb; /* ELSE or NULL */
+ basic_block join_bb = ce_info->join_bb; /* join block */
basic_block combo_bb;
/* All block merging is done into the lower block numbers. */
combo_bb = test_bb;
- /* First merge TEST block into THEN block. This is a no-brainer since
- the THEN block did not have a code label to begin with. */
+ /* Merge any basic blocks to handle && and || subtests. Each of
+ the blocks are on the fallthru path from the predecessor block. */
+ if (ce_info->num_multiple_test_blocks > 0)
+ {
+ basic_block bb = test_bb;
+ basic_block last_test_bb = ce_info->last_test_bb;
+ basic_block fallthru = block_fallthru (bb);
+
+ do
+ {
+ bb = fallthru;
+ fallthru = block_fallthru (bb);
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, bb);
+ merge_blocks_nomove (combo_bb, bb);
+ num_removed_blocks++;
+ }
+ while (bb != last_test_bb);
+ }
- if (life_data_ok)
- COPY_REG_SET (combo_bb->global_live_at_end, then_bb->global_live_at_end);
- merge_blocks_nomove (combo_bb, then_bb);
- num_removed_blocks++;
+ /* Merge TEST block into THEN block. Normally the THEN block won't have a
+ label, but it might if there were || tests. That label's count should be
+ zero, and it normally should be removed. */
+
+ if (then_bb)
+ {
+ if (combo_bb->global_live_at_end)
+ COPY_REG_SET (combo_bb->global_live_at_end,
+ then_bb->global_live_at_end);
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, then_bb);
+ merge_blocks_nomove (combo_bb, then_bb);
+ num_removed_blocks++;
+ }
/* The ELSE block, if it existed, had a label. That label count
will almost always be zero, but odd things can happen when labels
get their addresses taken. */
if (else_bb)
{
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, else_bb);
merge_blocks_nomove (combo_bb, else_bb);
num_removed_blocks++;
}
if (! join_bb)
{
+ rtx last = combo_bb->end;
+
/* The outgoing edge for the current COMBO block should already
be correct. Verify this. */
if (combo_bb->succ == NULL_EDGE)
- abort ();
+ {
+ if (find_reg_note (last, REG_NORETURN, NULL))
+ ;
+ else if (GET_CODE (last) == INSN
+ && GET_CODE (PATTERN (last)) == TRAP_IF
+ && TRAP_CONDITION (PATTERN (last)) == const_true_rtx)
+ ;
+ else
+ abort ();
+ }
- /* There should still be a branch at the end of the THEN or ELSE
+ /* There should still be something at the end of the THEN or ELSE
blocks taking us to our final destination. */
- if (GET_CODE (combo_bb->end) != JUMP_INSN)
+ else if (GET_CODE (last) == JUMP_INSN)
+ ;
+ else if (combo_bb->succ->dest == EXIT_BLOCK_PTR
+ && GET_CODE (last) == CALL_INSN
+ && SIBLING_CALL_P (last))
+ ;
+ else if ((combo_bb->succ->flags & EDGE_EH)
+ && can_throw_internal (last))
+ ;
+ else
abort ();
}
is more than one remaining edge, it must come from elsewhere. There
may be zero incoming edges if the THEN block didn't actually join
back up (as with a call to abort). */
- else if (join_bb->pred == NULL || join_bb->pred->pred_next == NULL)
+ else if ((join_bb->pred == NULL
+ || join_bb->pred->pred_next == NULL)
+ && join_bb != EXIT_BLOCK_PTR)
{
/* We can merge the JOIN. */
- if (life_data_ok)
+ if (combo_bb->global_live_at_end)
COPY_REG_SET (combo_bb->global_live_at_end,
join_bb->global_live_at_end);
+
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, join_bb);
merge_blocks_nomove (combo_bb, join_bb);
num_removed_blocks++;
}
abort ();
/* Remove the jump and cruft from the end of the COMBO block. */
- tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
+ if (join_bb != EXIT_BLOCK_PTR)
+ tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
}
- /* Make sure we update life info properly. */
- SET_UPDATE_LIFE (combo_bb);
-
num_updated_if_blocks++;
}
\f
-/* Find a block ending in a simple IF condition. Return TRUE if
- we were able to transform it in some way. */
+/* Find a block ending in a simple IF condition and try to transform it
+ in some way. When converting a multi-block condition, put the new code
+ in the first such block and delete the rest. Return a pointer to this
+ first block if some transformation was done. Return NULL otherwise. */
-static int
-find_if_header (test_bb)
+static basic_block
+find_if_header (test_bb, pass)
basic_block test_bb;
+ int pass;
{
+ ce_if_block_t ce_info;
edge then_edge;
edge else_edge;
if ((then_edge = test_bb->succ) == NULL_EDGE
|| (else_edge = then_edge->succ_next) == NULL_EDGE
|| else_edge->succ_next != NULL_EDGE)
- return FALSE;
+ return NULL;
/* Neither edge should be abnormal. */
if ((then_edge->flags & EDGE_COMPLEX)
|| (else_edge->flags & EDGE_COMPLEX))
- return FALSE;
+ return NULL;
/* The THEN edge is canonically the one that falls through. */
if (then_edge->flags & EDGE_FALLTHRU)
}
else
/* Otherwise this must be a multiway branch of some sort. */
- return FALSE;
+ return NULL;
- if (find_if_block (test_bb, then_edge, else_edge))
+ memset ((PTR) &ce_info, '\0', sizeof (ce_info));
+ ce_info.test_bb = test_bb;
+ ce_info.then_bb = then_edge->dest;
+ ce_info.else_bb = else_edge->dest;
+ ce_info.pass = pass;
+
+#ifdef IFCVT_INIT_EXTRA_FIELDS
+ IFCVT_INIT_EXTRA_FIELDS (&ce_info);
+#endif
+
+ if (find_if_block (&ce_info))
goto success;
+
if (HAVE_trap && HAVE_conditional_trap
&& find_cond_trap (test_bb, then_edge, else_edge))
goto success;
+
if (post_dominators
&& (! HAVE_conditional_execution || reload_completed))
{
goto success;
}
- return FALSE;
+ return NULL;
success:
if (rtl_dump_file)
- fprintf (rtl_dump_file, "Conversion succeeded.\n");
- return TRUE;
+ fprintf (rtl_dump_file, "Conversion succeeded on pass %d.\n", pass);
+ return ce_info.test_bb;
+}
+
+/* Return true if a block has two edges, one of which falls through to the next
+ block, and the other jumps to a specific block, so that we can tell if the
+ block is part of an && test or an || test. Returns either -1 or the number
+ of non-note, non-jump, non-USE/CLOBBER insns in the block. */
+
+static int
+block_jumps_and_fallthru_p (cur_bb, target_bb)
+ basic_block cur_bb;
+ basic_block target_bb;
+{
+ edge cur_edge;
+ int fallthru_p = FALSE;
+ int jump_p = FALSE;
+ rtx insn;
+ rtx end;
+ int n_insns = 0;
+
+ if (!cur_bb || !target_bb)
+ return -1;
+
+ /* If no edges, obviously it doesn't jump or fallthru. */
+ if (cur_bb->succ == NULL_EDGE)
+ return FALSE;
+
+ for (cur_edge = cur_bb->succ;
+ cur_edge != NULL_EDGE;
+ cur_edge = cur_edge->succ_next)
+ {
+ if (cur_edge->flags & EDGE_COMPLEX)
+ /* Anything complex isn't what we want. */
+ return -1;
+
+ else if (cur_edge->flags & EDGE_FALLTHRU)
+ fallthru_p = TRUE;
+
+ else if (cur_edge->dest == target_bb)
+ jump_p = TRUE;
+
+ else
+ return -1;
+ }
+
+ if ((jump_p & fallthru_p) == 0)
+ return -1;
+
+ /* Don't allow calls in the block, since this is used to group && and ||
+ together for conditional execution support. ??? we should support
+ conditional execution support across calls for IA-64 some day, but
+ for now it makes the code simpler. */
+ end = cur_bb->end;
+ insn = cur_bb->head;
+
+ while (insn != NULL_RTX)
+ {
+ if (GET_CODE (insn) == CALL_INSN)
+ return -1;
+
+ if (INSN_P (insn)
+ && GET_CODE (insn) != JUMP_INSN
+ && GET_CODE (PATTERN (insn)) != USE
+ && GET_CODE (PATTERN (insn)) != CLOBBER)
+ n_insns++;
+
+ if (insn == end)
+ break;
+
+ insn = NEXT_INSN (insn);
+ }
+
+ return n_insns;
}
/* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
block. If so, we'll try to convert the insns to not require the branch.
- Return TRUE if we were successful at converting the the block. */
+ Return TRUE if we were successful at converting the block. */
static int
-find_if_block (test_bb, then_edge, else_edge)
- basic_block test_bb;
- edge then_edge, else_edge;
+find_if_block (ce_info)
+ struct ce_if_block * ce_info;
{
- basic_block then_bb = then_edge->dest;
- basic_block else_bb = else_edge->dest;
+ basic_block test_bb = ce_info->test_bb;
+ basic_block then_bb = ce_info->then_bb;
+ basic_block else_bb = ce_info->else_bb;
basic_block join_bb = NULL_BLOCK;
edge then_succ = then_bb->succ;
edge else_succ = else_bb->succ;
- int next_index;
+ int then_predecessors;
+ int else_predecessors;
+ edge cur_edge;
+ basic_block next;
+
+ ce_info->last_test_bb = test_bb;
+
+ /* Discover if any fall through predecessors of the current test basic block
+ were && tests (which jump to the else block) or || tests (which jump to
+ the then block). */
+ if (HAVE_conditional_execution && reload_completed
+ && test_bb->pred != NULL_EDGE
+ && test_bb->pred->pred_next == NULL_EDGE
+ && test_bb->pred->flags == EDGE_FALLTHRU)
+ {
+ basic_block bb = test_bb->pred->src;
+ basic_block target_bb;
+ int max_insns = MAX_CONDITIONAL_EXECUTE;
+ int n_insns;
+
+ /* Determine if the preceeding block is an && or || block. */
+ if ((n_insns = block_jumps_and_fallthru_p (bb, else_bb)) >= 0)
+ {
+ ce_info->and_and_p = TRUE;
+ target_bb = else_bb;
+ }
+ else if ((n_insns = block_jumps_and_fallthru_p (bb, then_bb)) >= 0)
+ {
+ ce_info->and_and_p = FALSE;
+ target_bb = then_bb;
+ }
+ else
+ target_bb = NULL_BLOCK;
+
+ if (target_bb && n_insns <= max_insns)
+ {
+ int total_insns = 0;
+ int blocks = 0;
+
+ ce_info->last_test_bb = test_bb;
+
+ /* Found at least one && or || block, look for more. */
+ do
+ {
+ ce_info->test_bb = test_bb = bb;
+ total_insns += n_insns;
+ blocks++;
+
+ if (bb->pred == NULL_EDGE || bb->pred->pred_next != NULL_EDGE)
+ break;
+
+ bb = bb->pred->src;
+ n_insns = block_jumps_and_fallthru_p (bb, target_bb);
+ }
+ while (n_insns >= 0 && (total_insns + n_insns) <= max_insns);
+
+ ce_info->num_multiple_test_blocks = blocks;
+ ce_info->num_multiple_test_insns = total_insns;
- /* The THEN block of an IF-THEN combo must have exactly one predecessor. */
- if (then_bb->pred->pred_next != NULL_EDGE)
+ if (ce_info->and_and_p)
+ ce_info->num_and_and_blocks = blocks;
+ else
+ ce_info->num_or_or_blocks = blocks;
+ }
+ }
+
+ /* Count the number of edges the THEN and ELSE blocks have. */
+ then_predecessors = 0;
+ for (cur_edge = then_bb->pred;
+ cur_edge != NULL_EDGE;
+ cur_edge = cur_edge->pred_next)
+ {
+ then_predecessors++;
+ if (cur_edge->flags & EDGE_COMPLEX)
+ return FALSE;
+ }
+
+ else_predecessors = 0;
+ for (cur_edge = else_bb->pred;
+ cur_edge != NULL_EDGE;
+ cur_edge = cur_edge->pred_next)
+ {
+ else_predecessors++;
+ if (cur_edge->flags & EDGE_COMPLEX)
+ return FALSE;
+ }
+
+ /* The THEN block of an IF-THEN combo must have exactly one predecessor,
+ other than any || blocks which jump to the THEN block. */
+ if ((then_predecessors - ce_info->num_or_or_blocks) != 1)
return FALSE;
/* The THEN block of an IF-THEN combo must have zero or one successors. */
only one incoming edge -- the CFG manipulation is too ugly otherwise.
Check for the last insn of the THEN block being an indirect jump, which
is listed as not having any successors, but confuses the rest of the CE
- code processing. XXX we should fix this in the future. */
+ code processing. ??? we should fix this in the future. */
if (then_succ == NULL)
{
if (else_bb->pred->pred_next == NULL_EDGE)
if (rtl_dump_file)
{
- if (else_bb)
- fprintf (rtl_dump_file,
- "\nIF-THEN-ELSE block found, start %d, then %d, else %d, join %d\n",
- test_bb->index, then_bb->index, else_bb->index,
- join_bb->index);
- else
- fprintf (rtl_dump_file,
- "\nIF-THEN block found, start %d, then %d, join %d\n",
- test_bb->index, then_bb->index, join_bb->index);
- }
+ fprintf (rtl_dump_file, "\nIF-THEN%s block found, pass %d, start block %d [insn %d], then %d [%d]",
+ (else_bb) ? "-ELSE" : "",
+ ce_info->pass,
+ test_bb->index, (test_bb->head) ? (int)INSN_UID (test_bb->head) : -1,
+ then_bb->index, (then_bb->head) ? (int)INSN_UID (then_bb->head) : -1);
- /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we
- get the first condition for free, since we've already asserted that
- there's a fallthru edge from IF to THEN. */
+ if (else_bb)
+ fprintf (rtl_dump_file, ", else %d [%d]",
+ else_bb->index, (else_bb->head) ? (int)INSN_UID (else_bb->head) : -1);
+
+ fprintf (rtl_dump_file, ", join %d [%d]",
+ join_bb->index, (join_bb->head) ? (int)INSN_UID (join_bb->head) : -1);
+
+ if (ce_info->num_multiple_test_blocks > 0)
+ fprintf (rtl_dump_file, ", %d %s block%s last test %d [%d]",
+ ce_info->num_multiple_test_blocks,
+ (ce_info->and_and_p) ? "&&" : "||",
+ (ce_info->num_multiple_test_blocks == 1) ? "" : "s",
+ ce_info->last_test_bb->index,
+ ((ce_info->last_test_bb->head)
+ ? (int)INSN_UID (ce_info->last_test_bb->head)
+ : -1));
+
+ fputc ('\n', rtl_dump_file);
+ }
+
+ /* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we get the
+ first condition for free, since we've already asserted that there's a
+ fallthru edge from IF to THEN. Likewise for the && and || blocks, since
+ we checked the FALLTHRU flag, those are already adjacent to the last IF
+ block. */
/* ??? As an enhancement, move the ELSE block. Have to deal with
BLOCK notes, if by no other means than aborting the merge if they
exist. Sticky enough I don't want to think about it now. */
- next_index = then_bb->index;
- if (else_bb && ++next_index != else_bb->index)
+ next = then_bb;
+ if (else_bb && (next = next->next_bb) != else_bb)
return FALSE;
- if (++next_index != join_bb->index)
+ if ((next = next->next_bb) != join_bb && join_bb != EXIT_BLOCK_PTR)
{
if (else_bb)
join_bb = NULL;
}
/* Do the real work. */
- return process_if_block (test_bb, then_bb, else_bb, join_bb);
+ ce_info->else_bb = else_bb;
+ ce_info->join_bb = join_bb;
+
+ return process_if_block (ce_info);
}
-/* Convert a branch over a trap, or a branch to a trap,
- into a conditional trap. */
+/* Convert a branch over a trap, or a branch
+ to a trap, into a conditional trap. */
static int
find_cond_trap (test_bb, then_edge, else_edge)
basic_block test_bb;
edge then_edge, else_edge;
{
- basic_block then_bb, else_bb, join_bb, trap_bb;
+ basic_block then_bb = then_edge->dest;
+ basic_block else_bb = else_edge->dest;
+ basic_block other_bb, trap_bb;
rtx trap, jump, cond, cond_earliest, seq;
enum rtx_code code;
- then_bb = then_edge->dest;
- else_bb = else_edge->dest;
- join_bb = NULL;
-
/* Locate the block with the trap instruction. */
/* ??? While we look for no successors, we really ought to allow
EH successors. Need to fix merge_if_block for that to work. */
- /* ??? We can't currently handle merging the blocks if they are not
- already adjacent. Prevent losage in merge_if_block by detecting
- this now. */
- if (then_bb->succ == NULL)
- {
- trap_bb = then_bb;
- if (else_bb->index != then_bb->index + 1)
- return FALSE;
- join_bb = else_bb;
- else_bb = NULL;
- }
- else if (else_bb->succ == NULL)
- {
- trap_bb = else_bb;
- if (else_bb->index != then_bb->index + 1)
- else_bb = NULL;
- else if (then_bb->succ
- && ! then_bb->succ->succ_next
- && ! (then_bb->succ->flags & EDGE_COMPLEX)
- && then_bb->succ->dest->index == else_bb->index + 1)
- join_bb = then_bb->succ->dest;
- }
+ if ((trap = block_has_only_trap (then_bb)) != NULL)
+ trap_bb = then_bb, other_bb = else_bb;
+ else if ((trap = block_has_only_trap (else_bb)) != NULL)
+ trap_bb = else_bb, other_bb = then_bb;
else
return FALSE;
- /* Don't confuse a conditional return with something we want to
- optimize here. */
- if (trap_bb == EXIT_BLOCK_PTR)
- return FALSE;
-
- /* The only instruction in the THEN block must be the trap. */
- trap = first_active_insn (trap_bb);
- if (! (trap == trap_bb->end
- && GET_CODE (PATTERN (trap)) == TRAP_IF
- && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
- return FALSE;
-
if (rtl_dump_file)
{
- if (trap_bb == then_bb)
- fprintf (rtl_dump_file,
- "\nTRAP-IF block found, start %d, trap %d",
- test_bb->index, then_bb->index);
- else
- fprintf (rtl_dump_file,
- "\nTRAP-IF block found, start %d, then %d, trap %d",
- test_bb->index, then_bb->index, trap_bb->index);
- if (join_bb)
- fprintf (rtl_dump_file, ", join %d\n", join_bb->index);
- else
- fputc ('\n', rtl_dump_file);
+ fprintf (rtl_dump_file, "\nTRAP-IF block found, start %d, trap %d\n",
+ test_bb->index, trap_bb->index);
}
/* If this is not a standard conditional jump, we can't parse it. */
if (! cond)
return FALSE;
- /* If the conditional jump is more than just a conditional jump,
- then we can not do if-conversion on this block. */
+ /* If the conditional jump is more than just a conditional jump, then
+ we can not do if-conversion on this block. */
if (! onlyjump_p (jump))
return FALSE;
if (seq == NULL)
return FALSE;
- /* Emit the new insns before cond_earliest; delete the old jump
- and trap insns. */
-
- emit_insn_before (seq, cond_earliest);
-
- test_bb->end = PREV_INSN (jump);
- flow_delete_insn (jump);
+ /* Emit the new insns before cond_earliest. */
+ emit_insn_before_scope (seq, cond_earliest, INSN_SCOPE (trap));
- trap_bb->end = PREV_INSN (trap);
- flow_delete_insn (trap);
-
- /* Merge the blocks! */
- if (trap_bb != then_bb && ! else_bb)
+ /* Delete the trap block if possible. */
+ remove_edge (trap_bb == then_bb ? then_edge : else_edge);
+ if (trap_bb->pred == NULL)
{
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, trap_bb);
flow_delete_block (trap_bb);
num_removed_blocks++;
}
- merge_if_block (test_bb, then_bb, else_bb, join_bb);
+
+ /* If the non-trap block and the test are now adjacent, merge them.
+ Otherwise we must insert a direct branch. */
+ if (test_bb->next_bb == other_bb)
+ {
+ struct ce_if_block new_ce_info;
+ delete_insn (jump);
+ memset ((PTR) &new_ce_info, '\0', sizeof (new_ce_info));
+ new_ce_info.test_bb = test_bb;
+ new_ce_info.then_bb = NULL;
+ new_ce_info.else_bb = NULL;
+ new_ce_info.join_bb = other_bb;
+ merge_if_block (&new_ce_info);
+ }
+ else
+ {
+ rtx lab, newjump;
+
+ lab = JUMP_LABEL (jump);
+ newjump = emit_jump_insn_after (gen_jump (lab), jump);
+ LABEL_NUSES (lab) += 1;
+ JUMP_LABEL (newjump) = lab;
+ emit_barrier_after (newjump);
+
+ delete_insn (jump);
+ }
return TRUE;
}
+/* Subroutine of find_cond_trap: if BB contains only a trap insn,
+ return it. */
+
+static rtx
+block_has_only_trap (bb)
+ basic_block bb;
+{
+ rtx trap;
+
+ /* We're not the exit block. */
+ if (bb == EXIT_BLOCK_PTR)
+ return NULL_RTX;
+
+ /* The block must have no successors. */
+ if (bb->succ)
+ return NULL_RTX;
+
+ /* The only instruction in the THEN block must be the trap. */
+ trap = first_active_insn (bb);
+ if (! (trap == bb->end
+ && GET_CODE (PATTERN (trap)) == TRAP_IF
+ && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
+ return NULL_RTX;
+
+ return trap;
+}
+
/* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
transformable, but not necessarily the other. There need be no
JOIN block.
- Return TRUE if we were successful at converting the the block.
+ Return TRUE if we were successful at converting the block.
Cases we'd like to look at:
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest, new_bb;
edge then_succ = then_bb->succ;
+ int then_bb_index;
/* THEN has one successor. */
if (!then_succ || then_succ->succ_next != NULL)
/* Conversion went ok, including moving the insns and fixing up the
jump. Adjust the CFG to match. */
- SET_UPDATE_LIFE (test_bb);
bitmap_operation (test_bb->global_live_at_end,
else_bb->global_live_at_start,
then_bb->global_live_at_end, BITMAP_IOR);
new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb);
+ then_bb_index = then_bb->index;
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, then_bb);
+ flow_delete_block (then_bb);
+
/* Make rest of code believe that the newly created block is the THEN_BB
- block we are going to remove. */
+ block we removed. */
if (new_bb)
{
- new_bb->aux = then_bb->aux;
- SET_UPDATE_LIFE (then_bb);
+ new_bb->index = then_bb_index;
+ BASIC_BLOCK (then_bb_index) = new_bb;
}
- flow_delete_block (then_bb);
/* We've possibly created jump to next insn, cleanup_cfg will solve that
later. */
if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2)
;
else if (else_succ->dest->index < 0
- || TEST_BIT (post_dominators[ORIG_INDEX (then_bb)],
- ORIG_INDEX (else_succ->dest)))
+ || dominated_by_p (post_dominators, then_bb,
+ else_succ->dest))
;
else
return FALSE;
test_bb->index, else_bb->index);
/* ELSE is small. */
- if (count_bb_insns (then_bb) > BRANCH_COST)
+ if (count_bb_insns (else_bb) > BRANCH_COST)
return FALSE;
/* Registers set are dead, or are predicable. */
/* Conversion went ok, including moving the insns and fixing up the
jump. Adjust the CFG to match. */
- SET_UPDATE_LIFE (test_bb);
bitmap_operation (test_bb->global_live_at_end,
then_bb->global_live_at_start,
else_bb->global_live_at_end, BITMAP_IOR);
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, else_bb);
flow_delete_block (else_bb);
num_removed_blocks++;
basic_block new_dest;
int reversep;
{
- rtx head, end, jump, earliest, old_dest, new_label;
+ rtx head, end, jump, earliest, old_dest, new_label = NULL_RTX;
jump = test_bb->end;
prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
}
- if (! cond_exec_process_insns (head, end, cond, prob_val, 0))
+ if (! cond_exec_process_insns ((ce_if_block_t *)0, head, end, cond,
+ prob_val, 0))
goto cancel;
earliest = jump;
/* ??? Even non-trapping memories such as stack frame
references must be avoided. For stores, we collect
no lifetime info; for reads, we'd have to assert
- true_dependance false against every store in the
+ true_dependence false against every store in the
TEST range. */
if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
return FALSE;
change group management. */
old_dest = JUMP_LABEL (jump);
- new_label = block_label (new_dest);
- if (reversep
- ? ! invert_jump_1 (jump, new_label)
- : ! redirect_jump_1 (jump, new_label))
- goto cancel;
+ if (other_bb != new_dest)
+ {
+ new_label = block_label (new_dest);
+ if (reversep
+ ? ! invert_jump_1 (jump, new_label)
+ : ! redirect_jump_1 (jump, new_label))
+ goto cancel;
+ }
if (! apply_change_group ())
return FALSE;
- if (old_dest)
- LABEL_NUSES (old_dest) -= 1;
- if (new_label)
- LABEL_NUSES (new_label) += 1;
- JUMP_LABEL (jump) = new_label;
-
- if (reversep)
- invert_br_probabilities (jump);
-
- redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
- if (reversep)
+ if (other_bb != new_dest)
{
- gcov_type count, probability;
- count = BRANCH_EDGE (test_bb)->count;
- BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
- FALLTHRU_EDGE (test_bb)->count = count;
- probability = BRANCH_EDGE (test_bb)->probability;
- BRANCH_EDGE (test_bb)->probability = FALLTHRU_EDGE (test_bb)->probability;
- FALLTHRU_EDGE (test_bb)->probability = probability;
+ if (old_dest)
+ LABEL_NUSES (old_dest) -= 1;
+ if (new_label)
+ LABEL_NUSES (new_label) += 1;
+ JUMP_LABEL (jump) = new_label;
+ if (reversep)
+ invert_br_probabilities (jump);
+
+ redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
+ if (reversep)
+ {
+ gcov_type count, probability;
+ count = BRANCH_EDGE (test_bb)->count;
+ BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
+ FALLTHRU_EDGE (test_bb)->count = count;
+ probability = BRANCH_EDGE (test_bb)->probability;
+ BRANCH_EDGE (test_bb)->probability
+ = FALLTHRU_EDGE (test_bb)->probability;
+ FALLTHRU_EDGE (test_bb)->probability = probability;
+ update_br_prob_note (test_bb);
+ }
}
/* Move the insns out of MERGE_BB to before the branch. */
if (end == merge_bb->end)
merge_bb->end = PREV_INSN (head);
- head = squeeze_notes (head, end);
- if (GET_CODE (end) == NOTE
- && (NOTE_LINE_NUMBER (end) == NOTE_INSN_BLOCK_END
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_BLOCK_BEG
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_BEG
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_END
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_CONT
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_VTOP))
- {
- if (head == end)
- return TRUE;
- end = PREV_INSN (end);
- }
+ if (squeeze_notes (&head, &end))
+ return TRUE;
reorder_insns (head, end, PREV_INSN (earliest));
}
+
+ /* Remove the jump and edge if we can. */
+ if (other_bb == new_dest)
+ {
+ delete_insn (jump);
+ remove_edge (BRANCH_EDGE (test_bb));
+ /* ??? Can't merge blocks here, as then_bb is still in use.
+ At minimum, the merge will get done just before bb-reorder. */
+ }
+
return TRUE;
cancel:
if_convert (x_life_data_ok)
int x_life_data_ok;
{
- int block_num;
+ basic_block bb;
+ int pass;
num_possible_if_blocks = 0;
num_updated_if_blocks = 0;
num_removed_blocks = 0;
life_data_ok = (x_life_data_ok != 0);
- /* Free up basic_block_for_insn so that we don't have to keep it
+ /* Free up basic_block_for_insn so that we don't have to keep it
up to date, either here or in merge_blocks_nomove. */
free_basic_block_vars (1);
post_dominators = NULL;
if (HAVE_conditional_execution || life_data_ok)
{
- post_dominators = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
- calculate_dominance_info (NULL, post_dominators, CDI_POST_DOMINATORS);
+ post_dominators = calculate_dominance_info (CDI_POST_DOMINATORS);
}
+ if (life_data_ok)
+ clear_bb_flags ();
- /* Record initial block numbers. */
- for (block_num = 0; block_num < n_basic_blocks; block_num++)
- SET_ORIG_INDEX (BASIC_BLOCK (block_num), block_num);
-
- /* Go through each of the basic blocks looking for things to convert. */
- for (block_num = 0; block_num < n_basic_blocks; )
+ /* Go through each of the basic blocks looking for things to convert. If we
+ have conditional execution, we make multiple passes to allow us to handle
+ IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks. */
+ pass = 0;
+ do
{
- basic_block bb = BASIC_BLOCK (block_num);
- if (find_if_header (bb))
- block_num = bb->index;
- else
- block_num++;
+ cond_exec_changed_p = FALSE;
+ pass++;
+
+#ifdef IFCVT_MULTIPLE_DUMPS
+ if (rtl_dump_file && pass > 1)
+ fprintf (rtl_dump_file, "\n\n========== Pass %d ==========\n", pass);
+#endif
+
+ FOR_EACH_BB (bb)
+ {
+ basic_block new_bb;
+ while ((new_bb = find_if_header (bb, pass)))
+ bb = new_bb;
+ }
+
+#ifdef IFCVT_MULTIPLE_DUMPS
+ if (rtl_dump_file && cond_exec_changed_p)
+ print_rtl_with_bb (rtl_dump_file, get_insns ());
+#endif
}
+ while (cond_exec_changed_p);
+
+#ifdef IFCVT_MULTIPLE_DUMPS
+ if (rtl_dump_file)
+ fprintf (rtl_dump_file, "\n\n========== no more changes\n");
+#endif
if (post_dominators)
- sbitmap_vector_free (post_dominators);
+ free_dominance_info (post_dominators);
if (rtl_dump_file)
fflush (rtl_dump_file);
- /* Rebuild basic_block_for_insn for update_life_info and for gcse. */
- compute_bb_for_insn (get_max_uid ());
+ clear_aux_for_blocks ();
/* Rebuild life info for basic blocks that require it. */
if (num_removed_blocks && life_data_ok)
{
- sbitmap update_life_blocks = sbitmap_alloc (n_basic_blocks);
- sbitmap_zero (update_life_blocks);
-
/* If we allocated new pseudos, we must resize the array for sched1. */
if (max_regno < max_reg_num ())
{
max_regno = max_reg_num ();
allocate_reg_info (max_regno, FALSE, FALSE);
}
-
- for (block_num = 0; block_num < n_basic_blocks; block_num++)
- if (UPDATE_LIFE (BASIC_BLOCK (block_num)))
- SET_BIT (update_life_blocks, block_num);
-
- count_or_remove_death_notes (update_life_blocks, 1);
- /* ??? See about adding a mode that verifies that the initial
- set of blocks don't let registers come live. */
- update_life_info (update_life_blocks, UPDATE_LIFE_GLOBAL,
- PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
- | PROP_KILL_DEAD_CODE);
-
- sbitmap_free (update_life_blocks);
+ update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES,
+ PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
+ | PROP_KILL_DEAD_CODE);
}
/* Write the final stats. */
OSDN Git Service
