/* If-conversion support.
- Copyright (C) 2000 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
- This file is part of GNU CC.
+ This file is part of GCC.
- GNU CC is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
+ GCC is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
- GNU CC is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
+ GCC is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
You should have received a copy of the GNU General Public License
- along with GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with GCC; see the file COPYING. If not, write to the Free
+ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+ 02111-1307, USA. */
#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 "real.h"
#include "output.h"
+#include "optabs.h"
+#include "toplev.h"
#include "tm_p.h"
+#include "cfgloop.h"
+#include "target.h"
#ifndef HAVE_conditional_execution
#ifndef HAVE_decscc
#define HAVE_decscc 0
#endif
+#ifndef HAVE_trap
+#define HAVE_trap 0
+#endif
+#ifndef HAVE_conditional_trap
+#define HAVE_conditional_trap 0
+#endif
#ifndef MAX_CONDITIONAL_EXECUTE
#define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1)
/* # 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 int seq_contains_jump PARAMS ((rtx));
-
-static int cond_exec_process_insns PARAMS ((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 rtx noce_get_condition PARAMS ((rtx, 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 find_if_case_1 PARAMS ((basic_block, edge, edge));
-static int find_if_case_2 PARAMS ((basic_block, edge, edge));
-static int find_memory PARAMS ((rtx *, void *));
-static int dead_or_predicable PARAMS ((basic_block, basic_block,
- basic_block, rtx, int));
+static int count_bb_insns (basic_block);
+static rtx first_active_insn (basic_block);
+static rtx last_active_insn (basic_block, int);
+static int seq_contains_jump (rtx);
+static basic_block block_fallthru (basic_block);
+static int cond_exec_process_insns (ce_if_block_t *, rtx, rtx, rtx, rtx, int);
+static rtx cond_exec_get_condition (rtx);
+static int cond_exec_process_if_block (ce_if_block_t *, int);
+static rtx noce_get_condition (rtx, rtx *);
+static int noce_operand_ok (rtx);
+static int noce_process_if_block (ce_if_block_t *);
+static int process_if_block (ce_if_block_t *);
+static void merge_if_block (ce_if_block_t *);
+static int find_cond_trap (basic_block, edge, edge);
+static basic_block find_if_header (basic_block, int);
+static int block_jumps_and_fallthru_p (basic_block, basic_block);
+static int find_if_block (ce_if_block_t *);
+static int find_if_case_1 (basic_block, edge, edge);
+static int find_if_case_2 (basic_block, edge, edge);
+static int find_memory (rtx *, void *);
+static int dead_or_predicable (basic_block, basic_block, basic_block,
+ basic_block, int);
+static void noce_emit_move_insn (rtx, rtx);
+static rtx block_has_only_trap (basic_block);
+static void mark_loop_exit_edges (void);
\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. */
+/* Sets EDGE_LOOP_EXIT flag for all loop exits. */
+static void
+mark_loop_exit_edges ()
+{
+ struct loops loops;
+ basic_block bb;
+ edge e;
+
+ flow_loops_find (&loops, LOOP_TREE);
+
+ if (loops.num > 1)
+ {
+ FOR_EACH_BB (bb)
+ {
+ for (e = bb->succ; e; e = e->succ_next)
+ {
+ if (find_common_loop (bb->loop_father, e->dest->loop_father)
+ != bb->loop_father)
+ e->flags |= EDGE_LOOP_EXIT;
+ else
+ e->flags &= ~EDGE_LOOP_EXIT;
+ }
+ }
+ }
-#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)
+ flow_loops_free (&loops);
+}
-\f
/* Count the number of non-jump active insns in BB. */
static int
-count_bb_insns (bb)
- basic_block bb;
+count_bb_insns (basic_block bb)
{
int count = 0;
rtx insn = bb->head;
/* Return the first non-jump active insn in the basic block. */
static rtx
-first_active_insn (bb)
- basic_block bb;
+first_active_insn (basic_block bb)
{
rtx insn = bb->head;
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)
- basic_block bb;
- rtx insn;
+static rtx
+last_active_insn (basic_block bb, 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
+/* It is possible, especially when having dealt with multi-word
arithmetic, for the expanders to have emitted jumps. Search
through the sequence and return TRUE if a jump exists so that
we can abort the conversion. */
static int
-seq_contains_jump (insn)
- rtx insn;
+seq_contains_jump (rtx insn)
{
while (insn)
{
}
return 0;
}
+
+static basic_block
+block_fallthru (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)
- rtx start; /* first insn to look at */
- rtx end; /* last insn to look at */
- rtx test; /* conditional execution test */
- rtx prob_val; /* probability of branch taken. */
- int mod_ok; /* true if modifications ok last insn. */
+cond_exec_process_insns (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 */rtx prob_val,
+ /* probability of branch taken. */int mod_ok)
{
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)
/* Remove USE insns that get in the way. */
if (reload_completed && GET_CODE (PATTERN (insn)) == USE)
{
- /* ??? Ug. Actually unlinking the thing is problematic,
+ /* ??? Ug. Actually unlinking the thing is problematic,
given what we'd have to coordinate with our callers. */
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
/* 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),
/* Return the condition for a jump. Do not do any special processing. */
static rtx
-cond_exec_get_condition (jump)
- rtx jump;
+cond_exec_get_condition (rtx jump)
{
rtx test_if, cond;
reverse the condition. */
if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF
&& XEXP (XEXP (test_if, 2), 0) == JUMP_LABEL (jump))
- cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
- GET_MODE (cond), XEXP (cond, 0),
- XEXP (cond, 1));
+ {
+ enum rtx_code rev = reversed_comparison_code (cond, jump);
+ if (rev == UNKNOWN)
+ return NULL_RTX;
+
+ cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
+ XEXP (cond, 1));
+ }
return cond;
}
/* 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_if_block_t * ce_info,
+ /* if block information */int do_multiple_p)
{
+ 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 */
rtx else_start = NULL_RTX; /* first insn in ELSE block or NULL */
rtx else_end = NULL_RTX; /* last insn + 1 in ELSE block */
- int max; /* max # of insns to convert. */
+ int max; /* max # of insns to convert. */
int then_mod_ok; /* whether conditional mods are ok in THEN */
rtx true_expr; /* test for else block insns */
rtx false_expr; /* test for then block insns */
rtx true_prob_val; /* probability of else block */
rtx false_prob_val; /* probability of 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. */
/* 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;
/* Map test_expr/test_jump into the appropriate MD tests to use on
the conditionally executed code. */
-
+
true_expr = test_expr;
- false_expr = gen_rtx_fmt_ee (reverse_condition (GET_CODE (true_expr)),
- GET_MODE (true_expr), XEXP (true_expr, 0),
- XEXP (true_expr, 1));
+
+ false_code = reversed_comparison_code (true_expr, test_bb->end);
+ if (false_code != UNKNOWN)
+ false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr),
+ XEXP (true_expr, 0), XEXP (true_expr, 1));
+ else
+ false_expr = NULL_RTX;
#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);
to conditional execution. */
if (then_end
- && ! cond_exec_process_insns (then_start, then_end,
- false_expr, false_prob_val, then_mod_ok))
+ && (! false_expr
+ || ! 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);
return FALSE;
}
\f
-/* Used by noce_process_if_block to communicate with its subroutines.
+/* Used by noce_process_if_block to communicate with its subroutines.
The subroutines know that A and B may be evaluated freely. They
- know that X is a register. They should insert new instructions
+ know that X is a register. They should insert new instructions
before cond_earliest. */
struct noce_if_info
{
+ basic_block test_bb;
rtx insn_a, insn_b;
rtx x, a, b;
rtx jump, cond, cond_earliest;
};
-static rtx noce_emit_store_flag PARAMS ((struct noce_if_info *,
- rtx, int, int));
-static int noce_try_store_flag PARAMS ((struct noce_if_info *));
-static int noce_try_store_flag_inc PARAMS ((struct noce_if_info *));
-static int noce_try_store_flag_constants PARAMS ((struct noce_if_info *));
-static int noce_try_store_flag_mask PARAMS ((struct noce_if_info *));
-static rtx noce_emit_cmove PARAMS ((struct noce_if_info *,
- rtx, enum rtx_code, rtx,
- rtx, rtx, rtx));
-static int noce_try_cmove PARAMS ((struct noce_if_info *));
-static int noce_try_cmove_arith PARAMS ((struct noce_if_info *));
+static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
+static int noce_try_store_flag (struct noce_if_info *);
+static int noce_try_addcc (struct noce_if_info *);
+static int noce_try_store_flag_constants (struct noce_if_info *);
+static int noce_try_store_flag_mask (struct noce_if_info *);
+static rtx noce_emit_cmove (struct noce_if_info *, rtx, enum rtx_code, rtx,
+ rtx, rtx, rtx);
+static int noce_try_cmove (struct noce_if_info *);
+static int noce_try_cmove_arith (struct noce_if_info *);
+static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx *);
+static int noce_try_minmax (struct noce_if_info *);
+static int noce_try_abs (struct noce_if_info *);
/* Helper function for noce_try_store_flag*. */
static rtx
-noce_emit_store_flag (if_info, x, reversep, normalize)
- struct noce_if_info *if_info;
- rtx x;
- int reversep, normalize;
+noce_emit_store_flag (struct noce_if_info *if_info, rtx x, int reversep,
+ int normalize)
{
rtx cond = if_info->cond;
int cond_complex;
build the store_flag insn directly. */
if (cond_complex)
- cond = XEXP (SET_SRC (PATTERN (if_info->jump)), 0);
+ cond = XEXP (SET_SRC (pc_set (if_info->jump)), 0);
+
+ if (reversep)
+ code = reversed_comparison_code (cond, if_info->jump);
+ else
+ code = GET_CODE (cond);
if ((if_info->cond_earliest == if_info->jump || cond_complex)
&& (normalize == 0 || STORE_FLAG_VALUE == normalize))
{
rtx tmp;
- code = GET_CODE (cond);
- if (reversep)
- code = reverse_condition (code);
-
tmp = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0),
XEXP (cond, 1));
tmp = gen_rtx_SET (VOIDmode, x, tmp);
{
tmp = get_insns ();
end_sequence ();
- emit_insns (tmp);
+ emit_insn (tmp);
if_info->cond_earliest = if_info->jump;
end_sequence ();
}
- /* Don't even try if the comparison operands are weird. */
- if (cond_complex)
+ /* Don't even try if the comparison operands or the mode of X are weird. */
+ if (cond_complex || !SCALAR_INT_MODE_P (GET_MODE (x)))
return NULL_RTX;
- code = GET_CODE (cond);
- if (reversep)
- code = reverse_condition (code);
-
return emit_store_flag (x, code, XEXP (cond, 0),
XEXP (cond, 1), VOIDmode,
(code == LTU || code == LEU
|| code == GEU || code == GTU), normalize);
}
+/* Emit instruction to move an rtx into STRICT_LOW_PART. */
+static void
+noce_emit_move_insn (rtx x, rtx y)
+{
+ enum machine_mode outmode, inmode;
+ rtx outer, inner;
+ int bitpos;
+
+ if (GET_CODE (x) != STRICT_LOW_PART)
+ {
+ emit_move_insn (x, y);
+ return;
+ }
+
+ outer = XEXP (x, 0);
+ inner = XEXP (outer, 0);
+ 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));
+}
+
/* Convert "if (test) x = 1; else x = 0".
Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
a go at the conversion. */
static int
-noce_try_store_flag (if_info)
- struct noce_if_info *if_info;
+noce_try_store_flag (struct noce_if_info *if_info)
{
int reversep;
rtx target, seq;
else if (if_info->b == const0_rtx
&& GET_CODE (if_info->a) == CONST_INT
&& INTVAL (if_info->a) == STORE_FLAG_VALUE
- && can_reverse_comparison_p (if_info->cond, if_info->jump))
+ && (reversed_comparison_code (if_info->cond, if_info->jump)
+ != UNKNOWN))
reversep = 1;
else
return FALSE;
if (target)
{
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
return TRUE;
}
/* Convert "if (test) x = a; else x = b", for A and B constant. */
static int
-noce_try_store_flag_constants (if_info)
- struct noce_if_info *if_info;
+noce_try_store_flag_constants (struct noce_if_info *if_info)
{
rtx target, seq;
int reversep;
HOST_WIDE_INT itrue, ifalse, diff, tmp;
int normalize, can_reverse;
+ enum machine_mode mode;
if (! no_new_pseudos
&& GET_CODE (if_info->a) == CONST_INT
&& GET_CODE (if_info->b) == CONST_INT)
{
+ mode = GET_MODE (if_info->x);
ifalse = INTVAL (if_info->a);
itrue = INTVAL (if_info->b);
- diff = itrue - ifalse;
- can_reverse = can_reverse_comparison_p (if_info->cond, if_info->jump);
+ /* 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)
+ != UNKNOWN);
reversep = 0;
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
return FALSE;
if (reversep)
- {
+ {
tmp = itrue; itrue = ifalse; ifalse = tmp;
- diff = -diff;
+ diff = trunc_int_for_mode (-diff, mode);
}
start_sequence ();
=> x = 3 + (test == 0); */
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
{
- target = expand_binop (GET_MODE (if_info->x),
- (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 (GET_MODE (if_info->x), 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 (GET_MODE (if_info->x), 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 (GET_MODE (if_info->x), 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 (GET_MODE (if_info->x), 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 (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
return TRUE;
}
return FALSE;
}
-/* Convert "if (test) foo++" into "foo += (test != 0)", and
+/* Convert "if (test) foo++" into "foo += (test != 0)", and
similarly for "foo--". */
static int
-noce_try_store_flag_inc (if_info)
- struct noce_if_info *if_info;
+noce_try_addcc (struct noce_if_info *if_info)
{
rtx target, seq;
int subtract, normalize;
if (! no_new_pseudos
- && (BRANCH_COST >= 2
- || HAVE_incscc
- || HAVE_decscc)
/* Should be no `else' case to worry about. */
&& if_info->b == if_info->x
&& GET_CODE (if_info->a) == PLUS
- && (XEXP (if_info->a, 1) == const1_rtx
- || XEXP (if_info->a, 1) == constm1_rtx)
&& rtx_equal_p (XEXP (if_info->a, 0), if_info->x)
- && can_reverse_comparison_p (if_info->cond, if_info->jump))
+ && (reversed_comparison_code (if_info->cond, if_info->jump)
+ != UNKNOWN))
{
- if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
- subtract = 0, normalize = 0;
- else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
- subtract = 1, normalize = 0;
- else
- subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1));
-
- start_sequence ();
+ rtx cond = if_info->cond;
+ enum rtx_code code = reversed_comparison_code (cond, if_info->jump);
- target = noce_emit_store_flag (if_info,
- gen_reg_rtx (GET_MODE (if_info->x)),
- 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);
- if (target)
+ /* First try to use addcc pattern. */
+ if (general_operand (XEXP (cond, 0), VOIDmode)
+ && general_operand (XEXP (cond, 1), VOIDmode))
{
- if (target != if_info->x)
- emit_move_insn (if_info->x, target);
-
- seq = get_insns ();
+ start_sequence ();
+ target = emit_conditional_add (if_info->x, code,
+ XEXP (cond, 0), XEXP (cond, 1),
+ VOIDmode,
+ if_info->b, XEXP (if_info->a, 1),
+ GET_MODE (if_info->x),
+ (code == LTU || code == GEU
+ || code == LEU || code == GTU));
+ if (target)
+ {
+ if (target != if_info->x)
+ noce_emit_move_insn (if_info->x, target);
+
+ seq = get_insns ();
+ end_sequence ();
+ emit_insn_before_setloc (seq, if_info->jump,
+ INSN_LOCATOR (if_info->insn_a));
+ return TRUE;
+ }
end_sequence ();
+ }
- if (seq_contains_jump (seq))
- return FALSE;
+ /* If that fails, construct conditional increment or decrement using
+ setcc. */
+ if (BRANCH_COST >= 2
+ && (XEXP (if_info->a, 1) == const1_rtx
+ || XEXP (if_info->a, 1) == constm1_rtx))
+ {
+ start_sequence ();
+ if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
+ subtract = 0, normalize = 0;
+ else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
+ subtract = 1, normalize = 0;
+ else
+ subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1));
+
+
+ target = noce_emit_store_flag (if_info,
+ gen_reg_rtx (GET_MODE (if_info->x)),
+ 1, normalize);
- emit_insns_before (seq, if_info->cond_earliest);
+ if (target)
+ 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)
+ noce_emit_move_insn (if_info->x, target);
- return TRUE;
- }
+ seq = get_insns ();
+ end_sequence ();
- end_sequence ();
+ if (seq_contains_jump (seq))
+ return FALSE;
+
+ emit_insn_before_setloc (seq, if_info->jump,
+ INSN_LOCATOR (if_info->insn_a));
+
+ return TRUE;
+ }
+ end_sequence ();
+ }
}
return FALSE;
/* Convert "if (test) x = 0;" to "x &= -(test == 0);" */
static int
-noce_try_store_flag_mask (if_info)
- struct noce_if_info *if_info;
+noce_try_store_flag_mask (struct noce_if_info *if_info)
{
rtx target, seq;
int reversep;
|| STORE_FLAG_VALUE == -1)
&& ((if_info->a == const0_rtx
&& rtx_equal_p (if_info->b, if_info->x))
- || ((reversep = can_reverse_comparison_p (if_info->cond,
- if_info->jump))
+ || ((reversep = (reversed_comparison_code (if_info->cond,
+ if_info->jump)
+ != UNKNOWN))
&& if_info->b == const0_rtx
&& rtx_equal_p (if_info->a, if_info->x))))
{
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 (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
if (seq_contains_jump (seq))
return FALSE;
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_setloc (seq, if_info->jump,
+ INSN_LOCATOR (if_info->insn_a));
return TRUE;
}
/* Helper function for noce_try_cmove and noce_try_cmove_arith. */
static rtx
-noce_emit_cmove (if_info, x, code, cmp_a, cmp_b, vfalse, vtrue)
- struct noce_if_info *if_info;
- rtx x, cmp_a, cmp_b, vfalse, vtrue;
- enum rtx_code code;
+noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code,
+ rtx cmp_a, rtx cmp_b, rtx vfalse, rtx vtrue)
{
/* If earliest == jump, try to build the cmove insn directly.
This is helpful when combine has created some complex condition
{
tmp = get_insns ();
end_sequence ();
- emit_insns (tmp);
+ emit_insn (tmp);
return x;
}
#else
/* We'll never get here, as noce_process_if_block doesn't call the
functions involved. Ifdef code, however, should be discouraged
- because it leads to typos in the code not selected. However,
+ because it leads to typos in the code not selected. However,
emit_conditional_move won't exist either. */
return NULL_RTX;
#endif
has had a go at it. */
static int
-noce_try_cmove (if_info)
- struct noce_if_info *if_info;
+noce_try_cmove (struct noce_if_info *if_info)
{
enum rtx_code code;
rtx target, seq;
if (target)
{
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
- emit_insns_before (seq, if_info->cond_earliest);
+ emit_insn_before_setloc (seq, if_info->jump,
+ INSN_LOCATOR (if_info->insn_a));
return TRUE;
}
else
/* Try more complex cases involving conditional_move. */
static int
-noce_try_cmove_arith (if_info)
- struct noce_if_info *if_info;
+noce_try_cmove_arith (struct noce_if_info *if_info)
{
rtx a = if_info->a;
rtx b = if_info->b;
if (test)
x = y;
*/
-
+
code = GET_CODE (if_info->cond);
insn_a = if_info->insn_a;
insn_b = if_info->insn_b;
/* Possibly rearrange operands to make things come out more natural. */
- if (can_reverse_comparison_p (if_info->cond, if_info->jump))
+ if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
{
int reversep = 0;
if (rtx_equal_p (b, x))
if (reversep)
{
- code = reverse_condition (code);
+ code = reversed_comparison_code (if_info->cond, if_info->jump);
tmp = a, a = b, b = tmp;
tmp = insn_a, insn_a = insn_b, insn_b = tmp;
}
/* If either operand is complex, load it into a register first.
The best way to do this is to copy the original insn. In this
- way we preserve any clobbers etc that the insn may have had.
+ way we preserve any clobbers etc that the insn may have had.
This is of course not possible in the IS_MEM case. */
if (! general_operand (a, GET_MODE (a)))
{
if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b))
MEM_SCALAR_P (tmp) = 1;
if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
- MEM_ALIAS_SET (tmp) = MEM_ALIAS_SET (if_info->a);
+ 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)));
- emit_move_insn (if_info->x, tmp);
+ noce_emit_move_insn (if_info->x, tmp);
}
else if (target != x)
- emit_move_insn (x, target);
+ noce_emit_move_insn (x, target);
tmp = get_insns ();
end_sequence ();
- emit_insns_before (tmp, if_info->cond_earliest);
+ emit_insn_before_setloc (tmp, if_info->jump, INSN_LOCATOR (if_info->insn_a));
return TRUE;
end_seq_and_fail:
return FALSE;
}
-/* 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. */
+/* For most cases, the simplified condition we found is the best
+ choice, but this is not the case for the min/max/abs transforms.
+ For these we wish to know that it is A or B in the condition. */
static rtx
-noce_get_condition (jump, earliest)
- rtx jump;
- rtx *earliest;
+noce_get_alt_condition (struct noce_if_info *if_info, rtx target,
+ rtx *earliest)
{
- rtx cond;
- rtx set;
+ rtx cond, set, insn;
+ int reverse;
- /* If the condition variable is a register and is MODE_INT, accept it.
- Otherwise, fall back on get_condition. */
+ /* If target is already mentioned in the known condition, return it. */
+ if (reg_mentioned_p (target, if_info->cond))
+ {
+ *earliest = if_info->cond_earliest;
+ return if_info->cond;
+ }
- if (! any_condjump_p (jump))
- return NULL_RTX;
+ set = pc_set (if_info->jump);
+ cond = XEXP (SET_SRC (set), 0);
+ reverse
+ = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
+ && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
- set = pc_set (jump);
+ /* If we're looking for a constant, try to make the conditional
+ have that constant in it. There are two reasons why it may
+ not have the constant we want:
- cond = XEXP (SET_SRC (set), 0);
- if (GET_CODE (XEXP (cond, 0)) == REG
- && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_INT)
+ 1. GCC may have needed to put the constant in a register, because
+ the target can't compare directly against that constant. For
+ this case, we look for a SET immediately before the comparison
+ that puts a constant in that register.
+
+ 2. GCC may have canonicalized the conditional, for example
+ replacing "if x < 4" with "if x <= 3". We can undo that (or
+ make equivalent types of changes) to get the constants we need
+ if they're off by one in the right direction. */
+
+ if (GET_CODE (target) == CONST_INT)
{
- *earliest = jump;
+ enum rtx_code code = GET_CODE (if_info->cond);
+ rtx op_a = XEXP (if_info->cond, 0);
+ rtx op_b = XEXP (if_info->cond, 1);
+ rtx prev_insn;
+
+ /* First, look to see if we put a constant in a register. */
+ prev_insn = PREV_INSN (if_info->cond_earliest);
+ if (prev_insn
+ && INSN_P (prev_insn)
+ && GET_CODE (PATTERN (prev_insn)) == SET)
+ {
+ rtx src = find_reg_equal_equiv_note (prev_insn);
+ if (!src)
+ src = SET_SRC (PATTERN (prev_insn));
+ if (GET_CODE (src) == CONST_INT)
+ {
+ if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
+ op_a = src;
+ else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
+ op_b = src;
+
+ if (GET_CODE (op_a) == CONST_INT)
+ {
+ rtx tmp = op_a;
+ op_a = op_b;
+ op_b = tmp;
+ code = swap_condition (code);
+ }
+ }
+ }
- /* 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))
- cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
- GET_MODE (cond), XEXP (cond, 0),
- XEXP (cond, 1));
- }
- else
- cond = get_condition (jump, earliest);
+ /* Now, look to see if we can get the right constant by
+ adjusting the conditional. */
+ if (GET_CODE (op_b) == CONST_INT)
+ {
+ HOST_WIDE_INT desired_val = INTVAL (target);
+ HOST_WIDE_INT actual_val = INTVAL (op_b);
- return cond;
-}
+ switch (code)
+ {
+ case LT:
+ if (actual_val == desired_val + 1)
+ {
+ code = LE;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ case LE:
+ if (actual_val == desired_val - 1)
+ {
+ code = LT;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ case GT:
+ if (actual_val == desired_val - 1)
+ {
+ code = GE;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ case GE:
+ if (actual_val == desired_val + 1)
+ {
+ code = GT;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ default:
+ break;
+ }
+ }
-/* 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. */
+ /* If we made any changes, generate a new conditional that is
+ equivalent to what we started with, but has the right
+ constants in it. */
+ if (code != GET_CODE (if_info->cond)
+ || op_a != XEXP (if_info->cond, 0)
+ || op_b != XEXP (if_info->cond, 1))
+ {
+ cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
+ *earliest = if_info->cond_earliest;
+ return cond;
+ }
+ }
-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 */
-{
- /* We're looking for patterns of the form
+ cond = canonicalize_condition (if_info->jump, cond, reverse,
+ earliest, target);
+ if (! cond || ! reg_mentioned_p (target, cond))
+ return NULL;
- (1) if (...) x = a; else x = b;
- (2) x = b; if (...) x = a;
- (3) if (...) x = a; // as if with an initial x = x.
+ /* We almost certainly searched back to a different place.
+ Need to re-verify correct lifetimes. */
- The later patterns require jumps to be more expensive.
+ /* 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_overlap_mentioned_p (if_info->x, PATTERN (insn)))
+ return NULL;
- ??? For future expansion, look for multiple X in such patterns. */
+ /* A and B may not be modified in the range [cond_earliest, jump). */
+ for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn))
+ if (INSN_P (insn)
+ && (modified_in_p (if_info->a, insn)
+ || modified_in_p (if_info->b, insn)))
+ return 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, insn;
+ return cond;
+}
- /* If this is not a standard conditional jump, we can't parse it. */
- jump = test_bb->end;
- cond = noce_get_condition (jump, &if_info.cond_earliest);
- if (! cond)
- return FALSE;
+/* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc. */
- /* 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;
+static int
+noce_try_minmax (struct noce_if_info *if_info)
+{
+ rtx cond, earliest, target, seq;
+ enum rtx_code code, op;
+ int unsignedp;
- /* We must be comparing objects whose modes imply the size. */
- if (GET_MODE (XEXP (cond, 0)) == BLKmode)
+ /* ??? Can't guarantee that expand_binop won't create pseudos. */
+ if (no_new_pseudos)
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)
- || (set_a = single_set (insn_a)) == NULL_RTX)
+ /* ??? 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 (HONOR_SIGNED_ZEROS (GET_MODE (if_info->x))
+ || HONOR_NANS (GET_MODE (if_info->x)))
return FALSE;
- x = SET_DEST (set_a);
- a = SET_SRC (set_a);
+ cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
+ if (!cond)
+ return FALSE;
- /* Look for the other potential set. Make sure we've got equivalent
- destinations. */
- /* ??? This is overconservative. Storing to two different mems is
- as easy as conditionally computing the address. Storing to a
- single mem merely requires a scratch memory to use as one of the
- destination addresses; often the memory immediately below the
- stack pointer is available for this. */
- set_b = NULL_RTX;
- if (else_bb)
+ /* Verify the condition is of the form we expect, and canonicalize
+ the comparison code. */
+ code = GET_CODE (cond);
+ if (rtx_equal_p (XEXP (cond, 0), if_info->a))
{
- insn_b = first_active_insn (else_bb);
- if (! insn_b
- || ! last_active_insn_p (else_bb, insn_b)
- || (set_b = single_set (insn_b)) == NULL_RTX
- || ! rtx_equal_p (x, SET_DEST (set_b)))
+ if (! rtx_equal_p (XEXP (cond, 1), if_info->b))
return FALSE;
}
- else
+ else if (rtx_equal_p (XEXP (cond, 1), if_info->a))
{
- insn_b = prev_nonnote_insn (if_info.cond_earliest);
- if (! insn_b
- || 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)))
- insn_b = set_b = NULL_RTX;
+ if (! rtx_equal_p (XEXP (cond, 0), if_info->b))
+ return FALSE;
+ code = swap_condition (code);
}
- b = (set_b ? SET_SRC (set_b) : x);
+ else
+ return FALSE;
- /* 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))
+ /* Determine what sort of operation this is. Note that the code is for
+ a taken branch, so the code->operation mapping appears backwards. */
+ switch (code)
+ {
+ case LT:
+ case LE:
+ case UNLT:
+ case UNLE:
+ op = SMAX;
+ unsignedp = 0;
+ break;
+ case GT:
+ case GE:
+ case UNGT:
+ case UNGE:
+ op = SMIN;
+ unsignedp = 0;
+ break;
+ case LTU:
+ case LEU:
+ op = UMAX;
+ unsignedp = 1;
+ break;
+ case GTU:
+ case GEU:
+ op = UMIN;
+ unsignedp = 1;
+ break;
+ default:
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;
+ start_sequence ();
- /* Only operate on register destinations, and even then avoid extending
- the lifetime of hard registers on small register class machines. */
- orig_x = x;
- if (GET_CODE (x) != REG
- || (SMALL_REGISTER_CLASSES
- && REGNO (x) < FIRST_PSEUDO_REGISTER))
+ target = expand_simple_binop (GET_MODE (if_info->x), op,
+ if_info->a, if_info->b,
+ if_info->x, unsignedp, OPTAB_WIDEN);
+ if (! target)
{
- if (no_new_pseudos)
- return FALSE;
- x = gen_reg_rtx (GET_MODE (x));
+ end_sequence ();
+ return FALSE;
}
+ if (target != if_info->x)
+ noce_emit_move_insn (if_info->x, target);
- /* Don't operate on sources that may trap or are volatile. */
- if (side_effects_p (a) || side_effects_p (b)
- || (GET_CODE (a) != MEM && may_trap_p (a))
- || (GET_CODE (b) != MEM && may_trap_p (b)))
+ seq = get_insns ();
+ end_sequence ();
+
+ if (seq_contains_jump (seq))
return FALSE;
- /* Set up the info block for our subroutines. */
- if_info.cond = cond;
- if_info.jump = jump;
- if_info.insn_a = insn_a;
- if_info.insn_b = insn_b;
- if_info.x = x;
- if_info.a = a;
- if_info.b = b;
+ emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
+ if_info->cond = cond;
+ if_info->cond_earliest = earliest;
- /* Try optimizations in some approximation of a useful order. */
- /* ??? Should first look to see if X is live incoming at all. If it
+ return TRUE;
+}
+
+/* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */
+
+static int
+noce_try_abs (struct noce_if_info *if_info)
+{
+ rtx cond, earliest, target, seq, a, b, c;
+ int negate;
+
+ /* ??? Can't guarantee that expand_binop won't create pseudos. */
+ if (no_new_pseudos)
+ return FALSE;
+
+ /* Recognize A and B as constituting an ABS or NABS. */
+ a = if_info->a;
+ b = if_info->b;
+ if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
+ negate = 0;
+ else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
+ {
+ c = a; a = b; b = c;
+ negate = 1;
+ }
+ else
+ return FALSE;
+
+ cond = noce_get_alt_condition (if_info, b, &earliest);
+ if (!cond)
+ return FALSE;
+
+ /* Verify the condition is of the form we expect. */
+ if (rtx_equal_p (XEXP (cond, 0), b))
+ c = XEXP (cond, 1);
+ else if (rtx_equal_p (XEXP (cond, 1), b))
+ c = XEXP (cond, 0);
+ else
+ return FALSE;
+
+ /* Verify that C is zero. Search backward through the block for
+ a REG_EQUAL note if necessary. */
+ if (REG_P (c))
+ {
+ rtx insn, note = NULL;
+ for (insn = earliest;
+ insn != if_info->test_bb->head;
+ insn = PREV_INSN (insn))
+ if (INSN_P (insn)
+ && ((note = find_reg_note (insn, REG_EQUAL, c))
+ || (note = find_reg_note (insn, REG_EQUIV, c))))
+ break;
+ if (! note)
+ return FALSE;
+ c = XEXP (note, 0);
+ }
+ if (GET_CODE (c) == MEM
+ && GET_CODE (XEXP (c, 0)) == SYMBOL_REF
+ && CONSTANT_POOL_ADDRESS_P (XEXP (c, 0)))
+ c = get_pool_constant (XEXP (c, 0));
+
+ /* Work around funny ideas get_condition has wrt canonicalization.
+ Note that these rtx constants are known to be CONST_INT, and
+ therefore imply integer comparisons. */
+ if (c == constm1_rtx && GET_CODE (cond) == GT)
+ ;
+ else if (c == const1_rtx && GET_CODE (cond) == LT)
+ ;
+ else if (c != CONST0_RTX (GET_MODE (b)))
+ return FALSE;
+
+ /* Determine what sort of operation this is. */
+ switch (GET_CODE (cond))
+ {
+ case LT:
+ case LE:
+ case UNLT:
+ case UNLE:
+ negate = !negate;
+ break;
+ case GT:
+ case GE:
+ case UNGT:
+ case UNGE:
+ break;
+ default:
+ return FALSE;
+ }
+
+ start_sequence ();
+
+ target = expand_abs_nojump (GET_MODE (if_info->x), b, if_info->x, 1);
+
+ /* ??? It's a quandry whether cmove would be better here, especially
+ for integers. Perhaps combine will clean things up. */
+ if (target && negate)
+ target = expand_simple_unop (GET_MODE (target), NEG, target, if_info->x, 0);
+
+ if (! target)
+ {
+ end_sequence ();
+ return FALSE;
+ }
+
+ if (target != if_info->x)
+ noce_emit_move_insn (if_info->x, target);
+
+ seq = get_insns ();
+ end_sequence ();
+
+ if (seq_contains_jump (seq))
+ return FALSE;
+
+ emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATOR (if_info->insn_a));
+ if_info->cond = cond;
+ if_info->cond_earliest = earliest;
+
+ return TRUE;
+}
+
+/* Similar to get_condition, only the resulting condition must be
+ valid at JUMP, instead of at EARLIEST. */
+
+static rtx
+noce_get_condition (rtx jump, rtx *earliest)
+{
+ 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);
+ tmp = XEXP (cond, 0);
+ if (REG_P (tmp) && GET_MODE_CLASS (GET_MODE (tmp)) == MODE_INT)
+ {
+ *earliest = jump;
+
+ if (reverse)
+ cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
+ GET_MODE (cond), tmp, XEXP (cond, 1));
+ 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. */
+
+static int
+noce_operand_ok (rtx op)
+{
+ /* We special-case memories, so handle any of them with
+ no address side effects. */
+ if (GET_CODE (op) == MEM)
+ return ! side_effects_p (XEXP (op, 0));
+
+ if (side_effects_p (op))
+ return FALSE;
+
+ 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 block. */
+
+static int
+noce_process_if_block (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;
+ (2) x = b; if (...) x = a;
+ (3) if (...) x = a; // as if with an initial x = x.
+
+ The later patterns require jumps to be more expensive.
+
+ ??? For future expansion, look for multiple X in such patterns. */
+
+ /* 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;
+ cond = noce_get_condition (jump, &if_info.cond_earliest);
+ 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 (! onlyjump_p (jump))
+ return FALSE;
+
+ /* We must be comparing objects whose modes imply the size. */
+ if (GET_MODE (XEXP (cond, 0)) == BLKmode)
+ return FALSE;
+
+ /* Look for one of the potential sets. */
+ insn_a = first_active_insn (then_bb);
+ if (! insn_a
+ || insn_a != last_active_insn (then_bb, FALSE)
+ || (set_a = single_set (insn_a)) == NULL_RTX)
+ return FALSE;
+
+ x = SET_DEST (set_a);
+ a = SET_SRC (set_a);
+
+ /* Look for the other potential set. Make sure we've got equivalent
+ destinations. */
+ /* ??? This is overconservative. Storing to two different mems is
+ as easy as conditionally computing the address. Storing to a
+ single mem merely requires a scratch memory to use as one of the
+ destination addresses; often the memory immediately below the
+ stack pointer is available for this. */
+ set_b = NULL_RTX;
+ if (else_bb)
+ {
+ insn_b = first_active_insn (else_bb);
+ if (! 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;
+ }
+ else
+ {
+ insn_b = prev_nonnote_insn (if_info.cond_earliest);
+ /* We're going to be moving the evaluation of B down from above
+ COND_EARLIEST to JUMP. Make sure the relevant data is still
+ intact. */
+ if (! insn_b
+ || GET_CODE (insn_b) != INSN
+ || (set_b = single_set (insn_b)) == NULL_RTX
+ || ! rtx_equal_p (x, SET_DEST (set_b))
+ || reg_overlap_mentioned_p (x, SET_SRC (set_b))
+ || modified_between_p (SET_SRC (set_b),
+ PREV_INSN (if_info.cond_earliest), jump)
+ /* Likewise with X. In particular this can happen when
+ noce_get_condition looks farther back in the instruction
+ stream than one might expect. */
+ || reg_overlap_mentioned_p (x, cond)
+ || reg_overlap_mentioned_p (x, a)
+ || modified_between_p (x, PREV_INSN (if_info.cond_earliest), jump))
+ insn_b = set_b = NULL_RTX;
+ }
+
+ /* If x has side effects then only the if-then-else form is safe to
+ convert. But even in that case we would need to restore any notes
+ (such as REG_INC) at then end. That can be tricky if
+ noce_emit_move_insn expands to more than one insn, so disable the
+ optimization entirely for now if there are side effects. */
+ if (side_effects_p (x))
+ return FALSE;
+
+ b = (set_b ? SET_SRC (set_b) : x);
+
+ /* Only operate on register destinations, and even then avoid extending
+ the lifetime of hard registers on small register class machines. */
+ orig_x = x;
+ if (GET_CODE (x) != REG
+ || (SMALL_REGISTER_CLASSES
+ && REGNO (x) < FIRST_PSEUDO_REGISTER))
+ {
+ if (no_new_pseudos || GET_MODE (x) == BLKmode)
+ return FALSE;
+ x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
+ ? XEXP (x, 0) : x));
+ }
+
+ /* Don't operate on sources that may trap or are volatile. */
+ if (! noce_operand_ok (a) || ! noce_operand_ok (b))
+ return FALSE;
+
+ /* Set up the info block for our subroutines. */
+ if_info.test_bb = test_bb;
+ if_info.cond = cond;
+ if_info.jump = jump;
+ if_info.insn_a = insn_a;
+ if_info.insn_b = insn_b;
+ if_info.x = x;
+ if_info.a = a;
+ if_info.b = b;
+
+ /* Try optimizations in some approximation of a useful order. */
+ /* ??? Should first look to see if X is live incoming at all. If it
isn't, we don't need anything but an unconditional set. */
/* Look and see if A and B are really the same. Avoid creating silly
that case don't do anything and let the code below delete INSN_A. */
if (insn_b && else_bb)
{
+ rtx note;
+
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. */
+ if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
+ remove_note (insn_b, note);
+
insn_b = NULL_RTX;
}
/* If we have "x = b; if (...) x = a;", and x has side-effects, then
x must be executed twice. */
else if (insn_b && side_effects_p (orig_x))
return FALSE;
-
+
x = orig_x;
goto success;
}
if (noce_try_store_flag (&if_info))
goto success;
+ if (noce_try_minmax (&if_info))
+ goto success;
+ if (noce_try_abs (&if_info))
+ goto success;
if (HAVE_conditional_move
&& noce_try_cmove (&if_info))
goto success;
{
if (noce_try_store_flag_constants (&if_info))
goto success;
- if (noce_try_store_flag_inc (&if_info))
+ if (noce_try_addcc (&if_info))
goto success;
if (noce_try_store_flag_mask (&if_info))
goto success;
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 ();
- 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_setloc (insn_b, test_bb->end, INSN_LOCATOR (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 (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 (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);
- if (combo_bb->global_live_at_end)
- 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++;
+ do
+ {
+ bb = fallthru;
+ fallthru = block_fallthru (bb);
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, bb);
+ merge_blocks (combo_bb, bb);
+ num_removed_blocks++;
+ }
+ while (bb != last_test_bb);
+ }
+
+ /* 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 (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)
{
- merge_blocks_nomove (combo_bb, else_bb);
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, else_bb);
+ merge_blocks (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 sill 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 (! simplejump_p (combo_bb->end)
- && ! returnjump_p (combo_bb->end))
+ 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 ();
}
Since we've already merged the TEST, THEN and ELSE blocks, we should
have only one remaining edge from our if-then-else diamond. If there
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
+ 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 (combo_bb->global_live_at_end)
COPY_REG_SET (combo_bb->global_live_at_end,
join_bb->global_live_at_end);
- merge_blocks_nomove (combo_bb, join_bb);
+
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, join_bb);
+ merge_blocks (combo_bb, join_bb);
num_removed_blocks++;
}
else
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)
- basic_block test_bb;
+static basic_block
+find_if_header (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;
+
+ /* Nor exit the loop. */
+ if ((then_edge->flags & EDGE_LOOP_EXIT)
+ || (else_edge->flags & EDGE_LOOP_EXIT))
+ 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;
+
+ memset (&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;
- if (find_if_block (test_bb, then_edge, else_edge))
+#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 (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 (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 preceding 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++;
- /* The THEN block of an IF-THEN combo must have exactly one predecessor. */
- if (then_bb->pred->pred_next != NULL_EDGE)
+ 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;
+
+ 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. */
if (then_succ != NULL_EDGE
&& (then_succ->succ_next != NULL_EDGE
- || (then_succ->flags & EDGE_COMPLEX)))
+ || (then_succ->flags & EDGE_COMPLEX)
+ || (flow2_completed && tablejump_p (then_bb->end, NULL, NULL))))
return FALSE;
/* If the THEN block has no successors, conditional execution can still
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)
&& then_succ->dest == else_succ->dest
&& else_bb->pred->pred_next == NULL_EDGE
&& else_succ->succ_next == NULL_EDGE
- && ! (else_succ->flags & EDGE_COMPLEX))
+ && ! (else_succ->flags & EDGE_COMPLEX)
+ && ! (flow2_completed && tablejump_p (else_bb->end, NULL, NULL)))
join_bb = else_succ->dest;
/* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
else
- return FALSE;
+ return FALSE;
num_possible_if_blocks++;
if (rtl_dump_file)
{
+ 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);
+
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, ", 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. */
- /* ??? As an enhancement, move the ELSE block. Have to deal with EH and
+ /* 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. */
+
+static int
+find_cond_trap (basic_block test_bb, edge then_edge, edge else_edge)
+{
+ 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;
+
+ /* 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. */
+ 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;
+
+ if (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. */
+ jump = test_bb->end;
+ cond = noce_get_condition (jump, &cond_earliest);
+ 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 (! onlyjump_p (jump))
+ return FALSE;
+
+ /* We must be comparing objects whose modes imply the size. */
+ if (GET_MODE (XEXP (cond, 0)) == BLKmode)
+ return FALSE;
+
+ /* Reverse the comparison code, if necessary. */
+ code = GET_CODE (cond);
+ if (then_bb == trap_bb)
+ {
+ code = reversed_comparison_code (cond, jump);
+ if (code == UNKNOWN)
+ return FALSE;
+ }
+
+ /* Attempt to generate the conditional trap. */
+ seq = gen_cond_trap (code, XEXP (cond, 0), XEXP (cond, 1),
+ TRAP_CODE (PATTERN (trap)));
+ if (seq == NULL)
+ return FALSE;
+
+ /* Emit the new insns before cond_earliest. */
+ emit_insn_before_setloc (seq, cond_earliest, INSN_LOCATOR (trap));
+
+ /* 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);
+ delete_block (trap_bb);
+ num_removed_blocks++;
+ }
+
+ /* 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 (&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 (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:
/* Tests for case 1 above. */
static int
-find_if_case_1 (test_bb, then_edge, else_edge)
- basic_block test_bb;
- edge then_edge, else_edge;
+find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
{
basic_block then_bb = then_edge->dest;
- basic_block else_bb = else_edge->dest;
+ basic_block else_bb = else_edge->dest, new_bb;
edge then_succ = then_bb->succ;
- rtx new_lab;
+ int then_bb_index;
/* THEN has one successor. */
if (!then_succ || then_succ->succ_next != NULL)
if (then_bb->pred->pred_next != NULL)
return FALSE;
- /* ELSE follows THEN. (??? could be moved) */
- if (else_bb->index != then_bb->index + 1)
+ /* THEN must do something. */
+ if (forwarder_block_p (then_bb))
return FALSE;
num_possible_if_blocks++;
if (count_bb_insns (then_bb) > BRANCH_COST)
return FALSE;
- /* Find the label for THEN's destination. */
- if (then_succ->dest == EXIT_BLOCK_PTR)
- new_lab = NULL_RTX;
- else
- {
- new_lab = JUMP_LABEL (then_bb->end);
- if (! new_lab)
- abort ();
- }
-
/* Registers set are dead, or are predicable. */
- if (! dead_or_predicable (test_bb, then_bb, else_bb, new_lab, 1))
+ if (! dead_or_predicable (test_bb, then_bb, else_bb,
+ then_bb->succ->dest, 1))
return FALSE;
/* 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);
-
- make_edge (NULL, test_bb, then_succ->dest, 0);
- flow_delete_block (then_bb);
- tidy_fallthru_edge (else_edge, test_bb, else_bb);
+
+ 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);
+ delete_block (then_bb);
+
+ /* Make rest of code believe that the newly created block is the THEN_BB
+ block we removed. */
+ if (new_bb)
+ {
+ new_bb->index = then_bb_index;
+ BASIC_BLOCK (then_bb_index) = new_bb;
+ if (post_dominators)
+ add_to_dominance_info (post_dominators, new_bb);
+ }
+ /* We've possibly created jump to next insn, cleanup_cfg will solve that
+ later. */
num_removed_blocks++;
num_updated_if_blocks++;
/* Test for case 2 above. */
static int
-find_if_case_2 (test_bb, then_edge, else_edge)
- basic_block test_bb;
- edge then_edge, else_edge;
+find_if_case_2 (basic_block test_bb, edge then_edge, edge else_edge)
{
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest;
edge else_succ = else_bb->succ;
- rtx new_lab, note;
+ rtx note;
/* ELSE has one successor. */
if (!else_succ || else_succ->succ_next != NULL)
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;
- /* Find the label for ELSE's destination. */
- if (else_succ->dest == EXIT_BLOCK_PTR)
- new_lab = NULL_RTX;
- else
- {
- if (else_succ->flags & EDGE_FALLTHRU)
- {
- new_lab = else_succ->dest->head;
- if (GET_CODE (new_lab) != CODE_LABEL)
- abort ();
- }
- else
- {
- new_lab = JUMP_LABEL (else_bb->end);
- if (! new_lab)
- abort ();
- }
- }
-
/* Registers set are dead, or are predicable. */
- if (! dead_or_predicable (test_bb, else_bb, then_bb, new_lab, 0))
+ if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
return FALSE;
/* 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);
-
- remove_edge (else_edge);
- make_edge (NULL, test_bb, else_succ->dest, 0);
- flow_delete_block (else_bb);
+
+ if (post_dominators)
+ delete_from_dominance_info (post_dominators, else_bb);
+ delete_block (else_bb);
num_removed_blocks++;
num_updated_if_blocks++;
Return 1 if a memory is found. */
static int
-find_memory (px, data)
- rtx *px;
- void *data ATTRIBUTE_UNUSED;
+find_memory (rtx *px, void *data ATTRIBUTE_UNUSED)
{
return GET_CODE (*px) == MEM;
}
REVERSEP is true if the sense of the branch should be reversed. */
static int
-dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep)
- basic_block test_bb, merge_bb, other_bb;
- rtx new_dest;
- int reversep;
+dead_or_predicable (basic_block test_bb, basic_block merge_bb,
+ basic_block other_bb, basic_block new_dest, int reversep)
{
- rtx head, end, jump, earliest, old_dest;
+ rtx head, end, jump, earliest, old_dest, new_label = NULL_RTX;
jump = test_bb->end;
if (HAVE_conditional_execution)
{
/* In the conditional execution case, we have things easy. We know
- the condition is reversable. We don't have to check life info,
+ the condition is reversible. We don't have to check life info,
becase we're going to conditionally execute the code anyway.
All that's left is making sure the insns involved can actually
be predicated. */
rtx cond, prob_val;
cond = cond_exec_get_condition (jump);
+ if (! cond)
+ return FALSE;
prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
if (prob_val)
if (reversep)
{
- cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
- GET_MODE (cond), XEXP (cond, 0),
+ enum rtx_code rev = reversed_comparison_code (cond, jump);
+ if (rev == UNKNOWN)
+ return FALSE;
+ cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
XEXP (cond, 1));
if (prob_val)
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;
test_set = INITIALIZE_REG_SET (test_set_head);
/* ??? bb->local_set is only valid during calculate_global_regs_live,
- so we must recompute usage for MERGE_BB. Not so bad, I suppose,
+ so we must recompute usage for MERGE_BB. Not so bad, I suppose,
since we've already asserted that MERGE_BB is small. */
- propagate_block (merge_bb, tmp, merge_set, 0);
+ propagate_block (merge_bb, tmp, merge_set, merge_set, 0);
/* For small register class machines, don't lengthen lifetimes of
hard registers before reload. */
Moreover, we're interested in the insns live from OTHER_BB. */
COPY_REG_SET (test_live, other_bb->global_live_at_start);
- pbi = init_propagate_block_info (test_bb, test_live, test_set, 0);
+ pbi = init_propagate_block_info (test_bb, test_live, test_set, test_set,
+ 0);
for (insn = jump; ; insn = prev)
{
change group management. */
old_dest = JUMP_LABEL (jump);
- if (reversep
- ? ! invert_jump_1 (jump, new_dest)
- : ! redirect_jump_1 (jump, new_dest))
- 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_dest)
- LABEL_NUSES (new_dest) += 1;
- JUMP_LABEL (jump) = new_dest;
-
- if (reversep)
+ if (other_bb != new_dest)
{
- rtx note = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
- if (note)
- XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0)));
+ 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:
/* Main entry point for all if-conversion. */
void
-if_convert (life_data_ok)
- int life_data_ok;
+if_convert (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);
+
+ if (! (* targetm.cannot_modify_jumps_p) ())
+ mark_loop_exit_edges ();
- /* 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 up basic_block_for_insn so that we don't have to keep it
+ up to date, either here or in merge_blocks. */
free_basic_block_vars (1);
/* Compute postdominators if we think we'll use them. */
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. */
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