/* If-conversion support.
- Copyright (C) 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ Free Software Foundation, Inc.
This file is part of GCC.
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)
+ the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
License for more details.
You should have received a copy of the GNU General Public License
- 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. */
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tm_p.h"
#include "cfgloop.h"
#include "target.h"
-
+#include "timevar.h"
+#include "tree-pass.h"
+#include "df.h"
+#include "vec.h"
+#include "vecprim.h"
+#include "dbgcnt.h"
#ifndef HAVE_conditional_execution
#define HAVE_conditional_execution 0
#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)
+#define MAX_CONDITIONAL_EXECUTE \
+ (BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
+ + 1)
#endif
-#define NULL_EDGE ((edge) NULL)
+#define IFCVT_MULTIPLE_DUMPS 1
+
#define NULL_BLOCK ((basic_block) NULL)
/* # of IF-THEN or IF-THEN-ELSE blocks we looked at */
execution. */
static int num_updated_if_blocks;
-/* # of changes made which require life information to be updated. */
+/* # of changes made. */
static int num_true_changes;
/* Whether conditional execution changes were made. */
static int cond_exec_changed_p;
-/* True if life data ok at present. */
-static bool life_data_ok;
-
/* Forward references. */
-static int count_bb_insns (basic_block);
-static int total_bb_rtx_cost (basic_block);
+static int count_bb_insns (const_basic_block);
+static bool cheap_bb_rtx_cost_p (const_basic_block, int);
static rtx first_active_insn (basic_block);
static rtx last_active_insn (basic_block, int);
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 rtx noce_get_condition (rtx, rtx *, bool);
+static int noce_operand_ok (const_rtx);
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 noce_find_if_block (basic_block, edge, edge, int);
+static int cond_exec_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 *);
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
-/* Sets EDGE_LOOP_EXIT flag for all loop exits. */
-static void
-mark_loop_exit_edges (void)
-{
- struct loops loops;
- basic_block bb;
- edge e;
-
- flow_loops_find (&loops, LOOP_TREE);
- free_dominance_info (CDI_DOMINATORS);
-
- if (loops.num > 1)
- {
- FOR_EACH_BB (bb)
- {
- edge_iterator ei;
- FOR_EACH_EDGE (e, ei, bb->succs)
- {
- 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;
- }
- }
- }
-
- flow_loops_free (&loops);
-}
-
/* Count the number of non-jump active insns in BB. */
static int
-count_bb_insns (basic_block bb)
+count_bb_insns (const_basic_block bb)
{
int count = 0;
rtx insn = BB_HEAD (bb);
return count;
}
-/* Count the total insn_rtx_cost of non-jump active insns in BB.
- This function returns -1, if the cost of any instruction could
- not be estimated. */
+/* Determine whether the total insn_rtx_cost on non-jump insns in
+ basic block BB is less than MAX_COST. This function returns
+ false if the cost of any instruction could not be estimated. */
-static int
-total_bb_rtx_cost (basic_block bb)
+static bool
+cheap_bb_rtx_cost_p (const_basic_block bb, int max_cost)
{
int count = 0;
rtx insn = BB_HEAD (bb);
+ bool speed = optimize_bb_for_speed_p (bb);
while (1)
{
if (NONJUMP_INSN_P (insn))
{
- int cost = insn_rtx_cost (PATTERN (insn));
+ int cost = insn_rtx_cost (PATTERN (insn), speed);
if (cost == 0)
- return -1;
+ return false;
+
+ /* If this instruction is the load or set of a "stack" register,
+ such as a floating point register on x87, then the cost of
+ speculatively executing this insn may need to include
+ the additional cost of popping its result off of the
+ register stack. Unfortunately, correctly recognizing and
+ accounting for this additional overhead is tricky, so for
+ now we simply prohibit such speculative execution. */
+#ifdef STACK_REGS
+ {
+ rtx set = single_set (insn);
+ if (set && STACK_REG_P (SET_DEST (set)))
+ return false;
+ }
+#endif
+
count += cost;
+ if (count >= max_cost)
+ return false;
}
else if (CALL_P (insn))
- return -1;
-
+ return false;
+
if (insn == BB_END (bb))
break;
insn = NEXT_INSN (insn);
}
- return count;
+ return true;
}
/* Return the first non-jump active insn in the basic block. */
insn = NEXT_INSN (insn);
}
- while (NOTE_P (insn))
+ while (NOTE_P (insn) || DEBUG_INSN_P (insn))
{
if (insn == BB_END (bb))
return NULL_RTX;
while (NOTE_P (insn)
|| JUMP_P (insn)
+ || DEBUG_INSN_P (insn)
|| (skip_use_p
&& NONJUMP_INSN_P (insn)
&& GET_CODE (PATTERN (insn)) == USE))
for (insn = start; ; insn = NEXT_INSN (insn))
{
- if (NOTE_P (insn))
+ if (NOTE_P (insn) || DEBUG_INSN_P (insn))
goto insn_done;
- if (!NONJUMP_INSN_P (insn) && !CALL_P (insn))
- abort ();
+ gcc_assert(NONJUMP_INSN_P (insn) || CALL_P (insn));
/* Remove USE insns that get in the way. */
if (reload_completed && GET_CODE (PATTERN (insn)) == USE)
struct noce_if_info
{
- basic_block test_bb;
+ /* The basic blocks that make up the IF-THEN-{ELSE-,}JOIN block. */
+ basic_block test_bb, then_bb, else_bb, join_bb;
+
+ /* The jump that ends TEST_BB. */
+ rtx jump;
+
+ /* The jump condition. */
+ rtx cond;
+
+ /* New insns should be inserted before this one. */
+ rtx cond_earliest;
+
+ /* Insns in the THEN and ELSE block. There is always just this
+ one insns in those blocks. The insns are single_set insns.
+ If there was no ELSE block, INSN_B is the last insn before
+ COND_EARLIEST, or NULL_RTX. In the former case, the insn
+ operands are still valid, as if INSN_B was moved down below
+ the jump. */
rtx insn_a, insn_b;
- rtx x, a, b;
- rtx jump, cond, cond_earliest;
- /* True if "b" was originally evaluated unconditionally. */
- bool b_unconditional;
+
+ /* The SET_SRC of INSN_A and INSN_B. */
+ rtx a, b;
+
+ /* The SET_DEST of INSN_A. */
+ rtx x;
+
+ /* True if this if block is not canonical. In the canonical form of
+ if blocks, the THEN_BB is the block reached via the fallthru edge
+ from TEST_BB. For the noce transformations, we allow the symmetric
+ form as well. */
+ bool then_else_reversed;
+
+ /* Estimated cost of the particular branch instruction. */
+ int branch_cost;
};
static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
build the store_flag insn directly. */
if (cond_complex)
- cond = XEXP (SET_SRC (pc_set (if_info->jump)), 0);
+ {
+ rtx set = pc_set (if_info->jump);
+ cond = XEXP (SET_SRC (set), 0);
+ if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
+ && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump))
+ reversep = !reversep;
+ if (if_info->then_else_reversed)
+ reversep = !reversep;
+ }
if (reversep)
code = reversed_comparison_code (cond, if_info->jump);
static void
noce_emit_move_insn (rtx x, rtx y)
{
- enum machine_mode outmode, inmode;
+ enum machine_mode outmode;
rtx outer, inner;
int bitpos;
if (GET_CODE (x) != STRICT_LOW_PART)
{
- emit_move_insn (x, y);
+ rtx seq, insn, target;
+ optab ot;
+
+ start_sequence ();
+ /* Check that the SET_SRC is reasonable before calling emit_move_insn,
+ otherwise construct a suitable SET pattern ourselves. */
+ insn = (OBJECT_P (y) || CONSTANT_P (y) || GET_CODE (y) == SUBREG)
+ ? emit_move_insn (x, y)
+ : emit_insn (gen_rtx_SET (VOIDmode, x, y));
+ seq = get_insns ();
+ end_sequence ();
+
+ if (recog_memoized (insn) <= 0)
+ {
+ if (GET_CODE (x) == ZERO_EXTRACT)
+ {
+ rtx op = XEXP (x, 0);
+ unsigned HOST_WIDE_INT size = INTVAL (XEXP (x, 1));
+ unsigned HOST_WIDE_INT start = INTVAL (XEXP (x, 2));
+
+ /* store_bit_field expects START to be relative to
+ BYTES_BIG_ENDIAN and adjusts this value for machines with
+ BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN. In order to be able to
+ invoke store_bit_field again it is necessary to have the START
+ value from the first call. */
+ if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
+ {
+ if (MEM_P (op))
+ start = BITS_PER_UNIT - start - size;
+ else
+ {
+ gcc_assert (REG_P (op));
+ start = BITS_PER_WORD - start - size;
+ }
+ }
+
+ gcc_assert (start < (MEM_P (op) ? BITS_PER_UNIT : BITS_PER_WORD));
+ store_bit_field (op, size, start, GET_MODE (x), y);
+ return;
+ }
+
+ switch (GET_RTX_CLASS (GET_CODE (y)))
+ {
+ case RTX_UNARY:
+ ot = code_to_optab[GET_CODE (y)];
+ if (ot)
+ {
+ start_sequence ();
+ target = expand_unop (GET_MODE (y), ot, XEXP (y, 0), x, 0);
+ if (target != NULL_RTX)
+ {
+ if (target != x)
+ emit_move_insn (x, target);
+ seq = get_insns ();
+ }
+ end_sequence ();
+ }
+ break;
+
+ case RTX_BIN_ARITH:
+ case RTX_COMM_ARITH:
+ ot = code_to_optab[GET_CODE (y)];
+ if (ot)
+ {
+ start_sequence ();
+ target = expand_binop (GET_MODE (y), ot,
+ XEXP (y, 0), XEXP (y, 1),
+ x, 0, OPTAB_DIRECT);
+ if (target != NULL_RTX)
+ {
+ if (target != x)
+ emit_move_insn (x, target);
+ seq = get_insns ();
+ }
+ end_sequence ();
+ }
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ emit_insn (seq);
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);
}
int reversep;
rtx target, seq;
- if (GET_CODE (if_info->b) == CONST_INT
+ if (CONST_INT_P (if_info->b)
&& INTVAL (if_info->b) == STORE_FLAG_VALUE
&& if_info->a == const0_rtx)
reversep = 0;
else if (if_info->b == const0_rtx
- && GET_CODE (if_info->a) == CONST_INT
+ && CONST_INT_P (if_info->a)
&& INTVAL (if_info->a) == STORE_FLAG_VALUE
&& (reversed_comparison_code (if_info->cond, if_info->jump)
!= UNKNOWN))
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)
+ if (CONST_INT_P (if_info->a)
+ && CONST_INT_P (if_info->b))
{
mode = GET_MODE (if_info->x);
ifalse = INTVAL (if_info->a);
normalize = 0;
else if (ifalse == 0 && exact_log2 (itrue) >= 0
&& (STORE_FLAG_VALUE == 1
- || BRANCH_COST >= 2))
+ || if_info->branch_cost >= 2))
normalize = 1;
else if (itrue == 0 && exact_log2 (ifalse) >= 0 && can_reverse
- && (STORE_FLAG_VALUE == 1 || BRANCH_COST >= 2))
+ && (STORE_FLAG_VALUE == 1 || if_info->branch_cost >= 2))
normalize = 1, reversep = 1;
else if (itrue == -1
&& (STORE_FLAG_VALUE == -1
- || BRANCH_COST >= 2))
+ || if_info->branch_cost >= 2))
normalize = -1;
else if (ifalse == -1 && can_reverse
- && (STORE_FLAG_VALUE == -1 || BRANCH_COST >= 2))
+ && (STORE_FLAG_VALUE == -1 || if_info->branch_cost >= 2))
normalize = -1, reversep = 1;
- else if ((BRANCH_COST >= 2 && STORE_FLAG_VALUE == -1)
- || BRANCH_COST >= 3)
+ else if ((if_info->branch_cost >= 2 && STORE_FLAG_VALUE == -1)
+ || if_info->branch_cost >= 3)
normalize = -1;
else
return FALSE;
rtx target, seq;
int subtract, normalize;
- if (! no_new_pseudos
- && GET_CODE (if_info->a) == PLUS
+ if (GET_CODE (if_info->a) == PLUS
&& rtx_equal_p (XEXP (if_info->a, 0), if_info->b)
&& (reversed_comparison_code (if_info->cond, if_info->jump)
!= UNKNOWN))
/* If that fails, construct conditional increment or decrement using
setcc. */
- if (BRANCH_COST >= 2
+ if (if_info->branch_cost >= 2
&& (XEXP (if_info->a, 1) == const1_rtx
|| XEXP (if_info->a, 1) == constm1_rtx))
{
int reversep;
reversep = 0;
- if (! no_new_pseudos
- && (BRANCH_COST >= 2
- || STORE_FLAG_VALUE == -1)
+ if ((if_info->branch_cost >= 2
+ || STORE_FLAG_VALUE == -1)
&& ((if_info->a == const0_rtx
&& rtx_equal_p (if_info->b, if_info->x))
|| ((reversep = (reversed_comparison_code (if_info->cond,
rtx a = if_info->a;
rtx b = if_info->b;
rtx x = if_info->x;
+ rtx orig_a, orig_b;
rtx insn_a, insn_b;
rtx tmp, target;
int is_mem = 0;
conditional on their addresses followed by a load. Don't do this
early because it'll screw alias analysis. Note that we've
already checked for no side effects. */
- if (! no_new_pseudos && cse_not_expected
+ /* ??? FIXME: Magic number 5. */
+ if (cse_not_expected
&& MEM_P (a) && MEM_P (b)
- && BRANCH_COST >= 5)
+ && if_info->branch_cost >= 5)
{
a = XEXP (a, 0);
b = XEXP (b, 0);
if insn_rtx_cost can't be estimated. */
if (insn_a)
{
- insn_cost = insn_rtx_cost (PATTERN (insn_a));
- if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
+ insn_cost = insn_rtx_cost (PATTERN (insn_a),
+ optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_a)));
+ if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
return FALSE;
}
else
+ insn_cost = 0;
+
+ if (insn_b)
{
- insn_cost = 0;
+ insn_cost += insn_rtx_cost (PATTERN (insn_b),
+ optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn_b)));
+ if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (if_info->branch_cost))
+ return FALSE;
}
- if (insn_b) {
- insn_cost += insn_rtx_cost (PATTERN (insn_b));
- if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
- return FALSE;
- }
-
/* Possibly rearrange operands to make things come out more natural. */
if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
{
start_sequence ();
+ orig_a = a;
+ orig_b = b;
+
/* 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.
{
rtx set;
- if (no_new_pseudos)
- goto end_seq_and_fail;
-
if (is_mem)
{
tmp = gen_reg_rtx (GET_MODE (a));
}
if (! general_operand (b, GET_MODE (b)))
{
- rtx set;
-
- if (no_new_pseudos)
- goto end_seq_and_fail;
+ rtx set, last;
if (is_mem)
{
tmp = gen_reg_rtx (GET_MODE (b));
- tmp = emit_insn (gen_rtx_SET (VOIDmode,
- tmp,
- b));
+ tmp = gen_rtx_SET (VOIDmode, tmp, b);
}
else if (! insn_b)
goto end_seq_and_fail;
tmp = copy_rtx (insn_b);
set = single_set (tmp);
SET_DEST (set) = b;
- tmp = emit_insn (PATTERN (tmp));
+ tmp = PATTERN (tmp);
+ }
+
+ /* If insn to set up A clobbers any registers B depends on, try to
+ swap insn that sets up A with the one that sets up B. If even
+ that doesn't help, punt. */
+ last = get_last_insn ();
+ if (last && modified_in_p (orig_b, last))
+ {
+ tmp = emit_insn_before (tmp, get_insns ());
+ if (modified_in_p (orig_a, tmp))
+ goto end_seq_and_fail;
}
+ else
+ tmp = emit_insn (tmp);
+
if (recog_memoized (tmp) < 0)
goto end_seq_and_fail;
}
reverse
= GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
&& XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
+ if (if_info->then_else_reversed)
+ reverse = !reverse;
/* If we're looking for a constant, try to make the conditional
have that constant in it. There are two reasons why it may
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)
+ if (CONST_INT_P (target))
{
enum rtx_code code = GET_CODE (if_info->cond);
rtx op_a = XEXP (if_info->cond, 0);
rtx prev_insn;
/* First, look to see if we put a constant in a register. */
- prev_insn = PREV_INSN (if_info->cond_earliest);
+ prev_insn = prev_nonnote_insn (if_info->cond_earliest);
if (prev_insn
+ && BLOCK_NUM (prev_insn) == BLOCK_NUM (if_info->cond_earliest)
&& 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 (CONST_INT_P (src))
{
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)
+ if (CONST_INT_P (op_a))
{
rtx tmp = op_a;
op_a = op_b;
/* Now, look to see if we can get the right constant by
adjusting the conditional. */
- if (GET_CODE (op_b) == CONST_INT)
+ if (CONST_INT_P (op_b))
{
HOST_WIDE_INT desired_val = INTVAL (target);
HOST_WIDE_INT actual_val = INTVAL (op_b);
enum rtx_code code, op;
int unsignedp;
- /* ??? Can't guarantee that expand_binop won't create pseudos. */
- if (no_new_pseudos)
- return FALSE;
-
/* ??? 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... */
return TRUE;
}
-/* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);", etc. */
+/* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);",
+ "if (a < 0) x = ~a; else x = a;" to "x = one_cmpl_abs(a);",
+ etc. */
static int
noce_try_abs (struct noce_if_info *if_info)
{
rtx cond, earliest, target, seq, a, b, c;
int negate;
+ bool one_cmpl = false;
- /* ??? Can't guarantee that expand_binop won't create pseudos. */
- if (no_new_pseudos)
+ /* Reject modes with signed zeros. */
+ if (HONOR_SIGNED_ZEROS (GET_MODE (if_info->x)))
return FALSE;
- /* Recognize A and B as constituting an ABS or NABS. */
+ /* Recognize A and B as constituting an ABS or NABS. The canonical
+ form is a branch around the negation, taken when the object is the
+ first operand of a comparison against 0 that evaluates to true. */
a = if_info->a;
b = if_info->b;
if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
c = a; a = b; b = c;
negate = 1;
}
+ else if (GET_CODE (a) == NOT && rtx_equal_p (XEXP (a, 0), b))
+ {
+ negate = 0;
+ one_cmpl = true;
+ }
+ else if (GET_CODE (b) == NOT && rtx_equal_p (XEXP (b, 0), a))
+ {
+ c = a; a = b; b = c;
+ negate = 1;
+ one_cmpl = true;
+ }
else
return FALSE;
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);
+ {
+ c = XEXP (cond, 0);
+ negate = !negate;
+ }
else
return FALSE;
- /* Verify that C is zero. Search backward through the block for
- a REG_EQUAL note if necessary. */
+ /* Verify that C is zero. Search one step backward for a
+ REG_EQUAL note or a simple source if necessary. */
if (REG_P (c))
{
- rtx insn, note = NULL;
- for (insn = earliest;
- insn != BB_HEAD (if_info->test_bb);
- 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)
+ rtx set, insn = prev_nonnote_insn (earliest);
+ if (insn
+ && BLOCK_NUM (insn) == BLOCK_NUM (earliest)
+ && (set = single_set (insn))
+ && rtx_equal_p (SET_DEST (set), c))
+ {
+ rtx note = find_reg_equal_equiv_note (insn);
+ if (note)
+ c = XEXP (note, 0);
+ else
+ c = SET_SRC (set);
+ }
+ else
return FALSE;
- c = XEXP (note, 0);
}
if (MEM_P (c)
&& GET_CODE (XEXP (c, 0)) == SYMBOL_REF
}
start_sequence ();
-
- target = expand_abs_nojump (GET_MODE (if_info->x), b, if_info->x, 1);
+ if (one_cmpl)
+ target = expand_one_cmpl_abs_nojump (GET_MODE (if_info->x), b,
+ if_info->x);
+ else
+ target = expand_abs_nojump (GET_MODE (if_info->x), b, if_info->x, 1);
/* ??? It's a quandary 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 (one_cmpl)
+ target = expand_simple_unop (GET_MODE (target), NOT, target,
+ if_info->x, 0);
+ else
+ target = expand_simple_unop (GET_MODE (target), NEG, target,
+ if_info->x, 0);
+ }
if (! target)
{
rtx cond, t, m, c, seq;
enum machine_mode mode;
enum rtx_code code;
-
- if (no_new_pseudos)
- return FALSE;
+ bool t_unconditional;
cond = if_info->cond;
code = GET_CODE (cond);
if (GET_MODE (m) != mode)
return FALSE;
- /* This is only profitable if T is cheap, or T is unconditionally
- executed/evaluated in the original insn sequence. */
- if (rtx_cost (t, SET) >= COSTS_N_INSNS (2)
- && (!if_info->b_unconditional
- || t != if_info->b))
+ /* This is only profitable if T is unconditionally executed/evaluated in the
+ original insn sequence or T is cheap. The former happens if B is the
+ non-zero (T) value and if INSN_B was taken from TEST_BB, or there was no
+ INSN_B which can happen for e.g. conditional stores to memory. For the
+ cost computation use the block TEST_BB where the evaluation will end up
+ after the transformation. */
+ t_unconditional =
+ (t == if_info->b
+ && (if_info->insn_b == NULL_RTX
+ || BLOCK_FOR_INSN (if_info->insn_b) == if_info->test_bb));
+ if (!(t_unconditional
+ || (rtx_cost (t, SET, optimize_bb_for_speed_p (if_info->test_bb))
+ < COSTS_N_INSNS (2))))
return FALSE;
start_sequence ();
}
+/* Optimize away "if (x & C) x |= C" and similar bit manipulation
+ transformations. */
+
+static int
+noce_try_bitop (struct noce_if_info *if_info)
+{
+ rtx cond, x, a, result, seq;
+ enum machine_mode mode;
+ enum rtx_code code;
+ int bitnum;
+
+ x = if_info->x;
+ cond = if_info->cond;
+ code = GET_CODE (cond);
+
+ /* Check for no else condition. */
+ if (! rtx_equal_p (x, if_info->b))
+ return FALSE;
+
+ /* Check for a suitable condition. */
+ if (code != NE && code != EQ)
+ return FALSE;
+ if (XEXP (cond, 1) != const0_rtx)
+ return FALSE;
+ cond = XEXP (cond, 0);
+
+ /* ??? We could also handle AND here. */
+ if (GET_CODE (cond) == ZERO_EXTRACT)
+ {
+ if (XEXP (cond, 1) != const1_rtx
+ || !CONST_INT_P (XEXP (cond, 2))
+ || ! rtx_equal_p (x, XEXP (cond, 0)))
+ return FALSE;
+ bitnum = INTVAL (XEXP (cond, 2));
+ mode = GET_MODE (x);
+ if (BITS_BIG_ENDIAN)
+ bitnum = GET_MODE_BITSIZE (mode) - 1 - bitnum;
+ if (bitnum < 0 || bitnum >= HOST_BITS_PER_WIDE_INT)
+ return FALSE;
+ }
+ else
+ return FALSE;
+
+ a = if_info->a;
+ if (GET_CODE (a) == IOR || GET_CODE (a) == XOR)
+ {
+ /* Check for "if (X & C) x = x op C". */
+ if (! rtx_equal_p (x, XEXP (a, 0))
+ || !CONST_INT_P (XEXP (a, 1))
+ || (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
+ != (unsigned HOST_WIDE_INT) 1 << bitnum)
+ return FALSE;
+
+ /* if ((x & C) == 0) x |= C; is transformed to x |= C. */
+ /* if ((x & C) != 0) x |= C; is transformed to nothing. */
+ if (GET_CODE (a) == IOR)
+ result = (code == NE) ? a : NULL_RTX;
+ else if (code == NE)
+ {
+ /* if ((x & C) == 0) x ^= C; is transformed to x |= C. */
+ result = gen_int_mode ((HOST_WIDE_INT) 1 << bitnum, mode);
+ result = simplify_gen_binary (IOR, mode, x, result);
+ }
+ else
+ {
+ /* if ((x & C) != 0) x ^= C; is transformed to x &= ~C. */
+ result = gen_int_mode (~((HOST_WIDE_INT) 1 << bitnum), mode);
+ result = simplify_gen_binary (AND, mode, x, result);
+ }
+ }
+ else if (GET_CODE (a) == AND)
+ {
+ /* Check for "if (X & C) x &= ~C". */
+ if (! rtx_equal_p (x, XEXP (a, 0))
+ || !CONST_INT_P (XEXP (a, 1))
+ || (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
+ != (~((HOST_WIDE_INT) 1 << bitnum) & GET_MODE_MASK (mode)))
+ return FALSE;
+
+ /* if ((x & C) == 0) x &= ~C; is transformed to nothing. */
+ /* if ((x & C) != 0) x &= ~C; is transformed to x &= ~C. */
+ result = (code == EQ) ? a : NULL_RTX;
+ }
+ else
+ return FALSE;
+
+ if (result)
+ {
+ start_sequence ();
+ noce_emit_move_insn (x, result);
+ seq = end_ifcvt_sequence (if_info);
+ if (!seq)
+ return FALSE;
+
+ emit_insn_before_setloc (seq, if_info->jump,
+ INSN_LOCATOR (if_info->insn_a));
+ }
+ return TRUE;
+}
+
+
/* Similar to get_condition, only the resulting condition must be
- valid at JUMP, instead of at EARLIEST. */
+ valid at JUMP, instead of at EARLIEST.
+
+ If THEN_ELSE_REVERSED is true, the fallthrough does not go to the
+ THEN block of the caller, and we have to reverse the condition. */
static rtx
-noce_get_condition (rtx jump, rtx *earliest)
+noce_get_condition (rtx jump, rtx *earliest, bool then_else_reversed)
{
rtx cond, set, tmp;
bool reverse;
reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
&& XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump));
+ /* We may have to reverse because the caller's if block is not canonical,
+ i.e. the THEN block isn't the fallthrough block for the TEST block
+ (see find_if_header). */
+ if (then_else_reversed)
+ reverse = !reverse;
+
/* If the condition variable is a register and is MODE_INT, accept it. */
cond = XEXP (SET_SRC (set), 0);
/* Return true if OP is ok for if-then-else processing. */
static int
-noce_operand_ok (rtx op)
+noce_operand_ok (const_rtx op)
{
/* We special-case memories, so handle any of them with
no address side effects. */
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. */
+/* Return true if a write into MEM may trap or fault. */
+
+static bool
+noce_mem_write_may_trap_or_fault_p (const_rtx mem)
+{
+ rtx addr;
+
+ if (MEM_READONLY_P (mem))
+ return true;
+
+ if (may_trap_or_fault_p (mem))
+ return true;
+
+ addr = XEXP (mem, 0);
+
+ /* Call target hook to avoid the effects of -fpic etc.... */
+ addr = targetm.delegitimize_address (addr);
+
+ while (addr)
+ switch (GET_CODE (addr))
+ {
+ case CONST:
+ case PRE_DEC:
+ case PRE_INC:
+ case POST_DEC:
+ case POST_INC:
+ case POST_MODIFY:
+ addr = XEXP (addr, 0);
+ break;
+ case LO_SUM:
+ case PRE_MODIFY:
+ addr = XEXP (addr, 1);
+ break;
+ case PLUS:
+ if (CONST_INT_P (XEXP (addr, 1)))
+ addr = XEXP (addr, 0);
+ else
+ return false;
+ break;
+ case LABEL_REF:
+ return true;
+ case SYMBOL_REF:
+ if (SYMBOL_REF_DECL (addr)
+ && decl_readonly_section (SYMBOL_REF_DECL (addr), 0))
+ return true;
+ return false;
+ default:
+ return false;
+ }
+
+ return false;
+}
+
+/* Return whether we can use store speculation for MEM. TOP_BB is the
+ basic block above the conditional block where we are considering
+ doing the speculative store. We look for whether MEM is set
+ unconditionally later in the function. */
+
+static bool
+noce_can_store_speculate_p (basic_block top_bb, const_rtx mem)
+{
+ basic_block dominator;
+
+ for (dominator = get_immediate_dominator (CDI_POST_DOMINATORS, top_bb);
+ dominator != NULL;
+ dominator = get_immediate_dominator (CDI_POST_DOMINATORS, dominator))
+ {
+ rtx insn;
+
+ FOR_BB_INSNS (dominator, insn)
+ {
+ /* If we see something that might be a memory barrier, we
+ have to stop looking. Even if the MEM is set later in
+ the function, we still don't want to set it
+ unconditionally before the barrier. */
+ if (INSN_P (insn)
+ && (volatile_insn_p (PATTERN (insn))
+ || (CALL_P (insn) && (!RTL_CONST_CALL_P (insn)))))
+ return false;
+
+ if (memory_modified_in_insn_p (mem, insn))
+ return true;
+ if (modified_in_p (XEXP (mem, 0), insn))
+ return false;
+
+ }
+ }
+
+ return false;
+}
+
+/* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN 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)
+noce_process_if_block (struct noce_if_info *if_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;
+ basic_block test_bb = if_info->test_bb; /* test block */
+ basic_block then_bb = if_info->then_bb; /* THEN */
+ basic_block else_bb = if_info->else_bb; /* ELSE or NULL */
+ basic_block join_bb = if_info->join_bb; /* JOIN */
+ rtx jump = if_info->jump;
+ rtx cond = if_info->cond;
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
??? 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 = BB_END (test_bb);
- 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
}
else
{
- insn_b = prev_nonnote_insn (if_info.cond_earliest);
+ insn_b = prev_nonnote_insn (if_info->cond_earliest);
+ while (insn_b && DEBUG_INSN_P (insn_b))
+ insn_b = prev_nonnote_insn (insn_b);
/* 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
+ || BLOCK_NUM (insn_b) != BLOCK_NUM (if_info->cond_earliest)
|| !NONJUMP_INSN_P (insn_b)
|| (set_b = single_set (insn_b)) == NULL_RTX
|| ! rtx_equal_p (x, SET_DEST (set_b))
+ || ! noce_operand_ok (SET_SRC (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)
+ || modified_between_p (SET_SRC (set_b), insn_b, 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))
+ || modified_between_p (x, insn_b, jump))
insn_b = set_b = NULL_RTX;
}
|| (SMALL_REGISTER_CLASSES
&& REGNO (x) < FIRST_PSEUDO_REGISTER))
{
- if (no_new_pseudos || GET_MODE (x) == BLKmode)
+ if (GET_MODE (x) == BLKmode)
+ return FALSE;
+
+ if (GET_CODE (x) == ZERO_EXTRACT
+ && (!CONST_INT_P (XEXP (x, 1))
+ || !CONST_INT_P (XEXP (x, 2))))
return FALSE;
+
x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
? XEXP (x, 0) : x));
}
if (! noce_operand_ok (a) || ! noce_operand_ok (b))
return FALSE;
+ retry:
/* 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;
- if_info.b_unconditional = else_bb == 0;
+ 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
goto success;
}
- /* Disallow the "if (...) x = a;" form (with an implicit "else x = x;")
- for most optimizations if writing to x may trap, i.e. it's a memory
- other than a static var or a stack slot. */
- if (! set_b
- && MEM_P (orig_x)
- && ! MEM_NOTRAP_P (orig_x)
- && rtx_addr_can_trap_p (XEXP (orig_x, 0)))
+ if (!set_b && MEM_P (orig_x))
{
- if (HAVE_conditional_move)
- {
- if (noce_try_cmove (&if_info))
- goto success;
- if (! HAVE_conditional_execution
- && noce_try_cmove_arith (&if_info))
- goto success;
- }
- return FALSE;
+ /* Disallow the "if (...) x = a;" form (implicit "else x = x;")
+ for optimizations if writing to x may trap or fault,
+ i.e. it's a memory other than a static var or a stack slot,
+ is misaligned on strict aligned machines or is read-only. If
+ x is a read-only memory, then the program is valid only if we
+ avoid the store into it. If there are stores on both the
+ THEN and ELSE arms, then we can go ahead with the conversion;
+ either the program is broken, or the condition is always
+ false such that the other memory is selected. */
+ if (noce_mem_write_may_trap_or_fault_p (orig_x))
+ return FALSE;
+
+ /* Avoid store speculation: given "if (...) x = a" where x is a
+ MEM, we only want to do the store if x is always set
+ somewhere in the function. This avoids cases like
+ if (pthread_mutex_trylock(mutex))
+ ++global_variable;
+ where we only want global_variable to be changed if the mutex
+ is held. FIXME: This should ideally be expressed directly in
+ RTL somehow. */
+ if (!noce_can_store_speculate_p (test_bb, orig_x))
+ return FALSE;
}
- if (noce_try_move (&if_info))
+ if (noce_try_move (if_info))
goto success;
- if (noce_try_store_flag (&if_info))
+ if (noce_try_store_flag (if_info))
goto success;
- if (noce_try_minmax (&if_info))
+ if (noce_try_bitop (if_info))
goto success;
- if (noce_try_abs (&if_info))
+ 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))
+ && noce_try_cmove (if_info))
goto success;
if (! HAVE_conditional_execution)
{
- if (noce_try_store_flag_constants (&if_info))
+ if (noce_try_store_flag_constants (if_info))
goto success;
- if (noce_try_addcc (&if_info))
+ if (noce_try_addcc (if_info))
goto success;
- if (noce_try_store_flag_mask (&if_info))
+ if (noce_try_store_flag_mask (if_info))
goto success;
if (HAVE_conditional_move
- && noce_try_cmove_arith (&if_info))
+ && noce_try_cmove_arith (if_info))
goto success;
- if (noce_try_sign_mask (&if_info))
+ if (noce_try_sign_mask (if_info))
goto success;
}
+ if (!else_bb && set_b)
+ {
+ insn_b = set_b = NULL_RTX;
+ b = orig_x;
+ goto retry;
+ }
+
return FALSE;
success:
- /* The original sets may now be killed. */
- 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
- if it came from the ELSE block, because follows the now correct
- write that appears in the TEST block. However, if we got insn_b from
- 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)
- delete_insn (insn_b);
-
- /* 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)
{
+ rtx seq;
+
start_sequence ();
noce_emit_move_insn (orig_x, x);
- insn_b = get_insns ();
+ seq = get_insns ();
set_used_flags (orig_x);
- unshare_all_rtl_in_chain (insn_b);
+ unshare_all_rtl_in_chain (seq);
end_sequence ();
- emit_insn_after_setloc (insn_b, BB_END (test_bb), INSN_LOCATOR (insn_a));
+ emit_insn_before_setloc (seq, BB_END (test_bb), INSN_LOCATOR (insn_a));
}
- /* Merge the blocks! */
- merge_if_block (ce_info);
+ /* The original THEN and ELSE blocks may now be removed. The test block
+ must now jump to the join block. If the test block and the join block
+ can be merged, do so. */
+ if (else_bb)
+ {
+ delete_basic_block (else_bb);
+ num_true_changes++;
+ }
+ else
+ remove_edge (find_edge (test_bb, join_bb));
+
+ remove_edge (find_edge (then_bb, join_bb));
+ redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
+ delete_basic_block (then_bb);
+ num_true_changes++;
+
+ if (can_merge_blocks_p (test_bb, join_bb))
+ {
+ merge_blocks (test_bb, join_bb);
+ num_true_changes++;
+ }
+ num_updated_if_blocks++;
return TRUE;
}
-\f
-/* Attempt to convert an IF-THEN or IF-THEN-ELSE block into
- straight line code. Return true if successful. */
+
+/* Check whether a block is suitable for conditional move conversion.
+ Every insn must be a simple set of a register to a constant or a
+ register. For each assignment, store the value in the array VALS,
+ indexed by register number, then store the register number in
+ REGS. COND is the condition we will test. */
static int
-process_if_block (struct ce_if_block * ce_info)
+check_cond_move_block (basic_block bb, rtx *vals, VEC (int, heap) **regs, rtx cond)
{
- if (! reload_completed
- && noce_process_if_block (ce_info))
- return TRUE;
+ rtx insn;
- if (HAVE_conditional_execution && reload_completed)
+ /* We can only handle simple jumps at the end of the basic block.
+ It is almost impossible to update the CFG otherwise. */
+ insn = BB_END (bb);
+ if (JUMP_P (insn) && !onlyjump_p (insn))
+ return FALSE;
+
+ FOR_BB_INSNS (bb, insn)
{
- /* 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;
+ rtx set, dest, src;
- if (ce_info->num_multiple_test_blocks)
- {
- cancel_changes (0);
+ if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
+ continue;
+ set = single_set (insn);
+ if (!set)
+ return FALSE;
- if (cond_exec_process_if_block (ce_info, FALSE))
- return TRUE;
- }
- }
+ dest = SET_DEST (set);
+ src = SET_SRC (set);
+ if (!REG_P (dest)
+ || (SMALL_REGISTER_CLASSES && HARD_REGISTER_P (dest)))
+ return FALSE;
- return FALSE;
-}
+ if (!CONSTANT_P (src) && !register_operand (src, VOIDmode))
+ return FALSE;
-/* Merge the blocks and mark for local life update. */
+ if (side_effects_p (src) || side_effects_p (dest))
+ return FALSE;
-static void
-merge_if_block (struct ce_if_block * ce_info)
-{
+ if (may_trap_p (src) || may_trap_p (dest))
+ return FALSE;
+
+ /* Don't try to handle this if the source register was
+ modified earlier in the block. */
+ if ((REG_P (src)
+ && vals[REGNO (src)] != NULL)
+ || (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
+ && vals[REGNO (SUBREG_REG (src))] != NULL))
+ return FALSE;
+
+ /* Don't try to handle this if the destination register was
+ modified earlier in the block. */
+ if (vals[REGNO (dest)] != NULL)
+ return FALSE;
+
+ /* Don't try to handle this if the condition uses the
+ destination register. */
+ if (reg_overlap_mentioned_p (dest, cond))
+ return FALSE;
+
+ /* Don't try to handle this if the source register is modified
+ later in the block. */
+ if (!CONSTANT_P (src)
+ && modified_between_p (src, insn, NEXT_INSN (BB_END (bb))))
+ return FALSE;
+
+ vals[REGNO (dest)] = src;
+
+ VEC_safe_push (int, heap, *regs, REGNO (dest));
+ }
+
+ return TRUE;
+}
+
+/* Given a basic block BB suitable for conditional move conversion,
+ a condition COND, and arrays THEN_VALS and ELSE_VALS containing the
+ register values depending on COND, emit the insns in the block as
+ conditional moves. If ELSE_BLOCK is true, THEN_BB was already
+ processed. The caller has started a sequence for the conversion.
+ Return true if successful, false if something goes wrong. */
+
+static bool
+cond_move_convert_if_block (struct noce_if_info *if_infop,
+ basic_block bb, rtx cond,
+ rtx *then_vals, rtx *else_vals,
+ bool else_block_p)
+{
+ enum rtx_code code;
+ rtx insn, cond_arg0, cond_arg1;
+
+ code = GET_CODE (cond);
+ cond_arg0 = XEXP (cond, 0);
+ cond_arg1 = XEXP (cond, 1);
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ rtx set, target, dest, t, e;
+ unsigned int regno;
+
+ /* ??? Maybe emit conditional debug insn? */
+ if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
+ continue;
+ set = single_set (insn);
+ gcc_assert (set && REG_P (SET_DEST (set)));
+
+ dest = SET_DEST (set);
+ regno = REGNO (dest);
+
+ t = then_vals[regno];
+ e = else_vals[regno];
+
+ if (else_block_p)
+ {
+ /* If this register was set in the then block, we already
+ handled this case there. */
+ if (t)
+ continue;
+ t = dest;
+ gcc_assert (e);
+ }
+ else
+ {
+ gcc_assert (t);
+ if (!e)
+ e = dest;
+ }
+
+ target = noce_emit_cmove (if_infop, dest, code, cond_arg0, cond_arg1,
+ t, e);
+ if (!target)
+ return false;
+
+ if (target != dest)
+ noce_emit_move_insn (dest, target);
+ }
+
+ return true;
+}
+
+/* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
+ it using only conditional moves. Return TRUE if we were successful at
+ converting the block. */
+
+static int
+cond_move_process_if_block (struct noce_if_info *if_info)
+{
+ basic_block test_bb = if_info->test_bb;
+ basic_block then_bb = if_info->then_bb;
+ basic_block else_bb = if_info->else_bb;
+ basic_block join_bb = if_info->join_bb;
+ rtx jump = if_info->jump;
+ rtx cond = if_info->cond;
+ rtx seq, loc_insn;
+ int max_reg, size, c, reg;
+ rtx *then_vals;
+ rtx *else_vals;
+ VEC (int, heap) *then_regs = NULL;
+ VEC (int, heap) *else_regs = NULL;
+ unsigned int i;
+
+ /* Build a mapping for each block to the value used for each
+ register. */
+ max_reg = max_reg_num ();
+ size = (max_reg + 1) * sizeof (rtx);
+ then_vals = (rtx *) alloca (size);
+ else_vals = (rtx *) alloca (size);
+ memset (then_vals, 0, size);
+ memset (else_vals, 0, size);
+
+ /* Make sure the blocks are suitable. */
+ if (!check_cond_move_block (then_bb, then_vals, &then_regs, cond)
+ || (else_bb && !check_cond_move_block (else_bb, else_vals, &else_regs, cond)))
+ {
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
+
+ /* Make sure the blocks can be used together. If the same register
+ is set in both blocks, and is not set to a constant in both
+ cases, then both blocks must set it to the same register. We
+ have already verified that if it is set to a register, that the
+ source register does not change after the assignment. Also count
+ the number of registers set in only one of the blocks. */
+ c = 0;
+ for (i = 0; VEC_iterate (int, then_regs, i, reg); i++)
+ {
+ if (!then_vals[reg] && !else_vals[reg])
+ continue;
+
+ if (!else_vals[reg])
+ ++c;
+ else
+ {
+ if (!CONSTANT_P (then_vals[reg])
+ && !CONSTANT_P (else_vals[reg])
+ && !rtx_equal_p (then_vals[reg], else_vals[reg]))
+ {
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
+ }
+ }
+
+ /* Finish off c for MAX_CONDITIONAL_EXECUTE. */
+ for (i = 0; VEC_iterate (int, else_regs, i, reg); ++i)
+ if (!then_vals[reg])
+ ++c;
+
+ /* Make sure it is reasonable to convert this block. What matters
+ is the number of assignments currently made in only one of the
+ branches, since if we convert we are going to always execute
+ them. */
+ if (c > MAX_CONDITIONAL_EXECUTE)
+ {
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
+
+ /* Try to emit the conditional moves. First do the then block,
+ then do anything left in the else blocks. */
+ start_sequence ();
+ if (!cond_move_convert_if_block (if_info, then_bb, cond,
+ then_vals, else_vals, false)
+ || (else_bb
+ && !cond_move_convert_if_block (if_info, else_bb, cond,
+ then_vals, else_vals, true)))
+ {
+ end_sequence ();
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
+ seq = end_ifcvt_sequence (if_info);
+ if (!seq)
+ {
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
+
+ loc_insn = first_active_insn (then_bb);
+ if (!loc_insn)
+ {
+ loc_insn = first_active_insn (else_bb);
+ gcc_assert (loc_insn);
+ }
+ emit_insn_before_setloc (seq, jump, INSN_LOCATOR (loc_insn));
+
+ if (else_bb)
+ {
+ delete_basic_block (else_bb);
+ num_true_changes++;
+ }
+ else
+ remove_edge (find_edge (test_bb, join_bb));
+
+ remove_edge (find_edge (then_bb, join_bb));
+ redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
+ delete_basic_block (then_bb);
+ num_true_changes++;
+
+ if (can_merge_blocks_p (test_bb, join_bb))
+ {
+ merge_blocks (test_bb, join_bb);
+ num_true_changes++;
+ }
+
+ num_updated_if_blocks++;
+
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return TRUE;
+}
+
+\f
+/* Determine if a given basic block heads a simple IF-THEN-JOIN or an
+ IF-THEN-ELSE-JOIN block.
+
+ If so, we'll try to convert the insns to not require the branch,
+ using only transformations that do not require conditional execution.
+
+ Return TRUE if we were successful at converting the block. */
+
+static int
+noce_find_if_block (basic_block test_bb,
+ edge then_edge, edge else_edge,
+ int pass)
+{
+ basic_block then_bb, else_bb, join_bb;
+ bool then_else_reversed = false;
+ rtx jump, cond;
+ rtx cond_earliest;
+ struct noce_if_info if_info;
+
+ /* We only ever should get here before reload. */
+ gcc_assert (!reload_completed);
+
+ /* Recognize an IF-THEN-ELSE-JOIN block. */
+ if (single_pred_p (then_edge->dest)
+ && single_succ_p (then_edge->dest)
+ && single_pred_p (else_edge->dest)
+ && single_succ_p (else_edge->dest)
+ && single_succ (then_edge->dest) == single_succ (else_edge->dest))
+ {
+ then_bb = then_edge->dest;
+ else_bb = else_edge->dest;
+ join_bb = single_succ (then_bb);
+ }
+ /* Recognize an IF-THEN-JOIN block. */
+ else if (single_pred_p (then_edge->dest)
+ && single_succ_p (then_edge->dest)
+ && single_succ (then_edge->dest) == else_edge->dest)
+ {
+ then_bb = then_edge->dest;
+ else_bb = NULL_BLOCK;
+ join_bb = else_edge->dest;
+ }
+ /* Recognize an IF-ELSE-JOIN block. We can have those because the order
+ of basic blocks in cfglayout mode does not matter, so the fallthrough
+ edge can go to any basic block (and not just to bb->next_bb, like in
+ cfgrtl mode). */
+ else if (single_pred_p (else_edge->dest)
+ && single_succ_p (else_edge->dest)
+ && single_succ (else_edge->dest) == then_edge->dest)
+ {
+ /* The noce transformations do not apply to IF-ELSE-JOIN blocks.
+ To make this work, we have to invert the THEN and ELSE blocks
+ and reverse the jump condition. */
+ then_bb = else_edge->dest;
+ else_bb = NULL_BLOCK;
+ join_bb = single_succ (then_bb);
+ then_else_reversed = true;
+ }
+ else
+ /* Not a form we can handle. */
+ return FALSE;
+
+ /* The edges of the THEN and ELSE blocks cannot have complex edges. */
+ if (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
+ return FALSE;
+ if (else_bb
+ && single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
+ return FALSE;
+
+ num_possible_if_blocks++;
+
+ if (dump_file)
+ {
+ fprintf (dump_file,
+ "\nIF-THEN%s-JOIN block found, pass %d, test %d, then %d",
+ (else_bb) ? "-ELSE" : "",
+ pass, test_bb->index, then_bb->index);
+
+ if (else_bb)
+ fprintf (dump_file, ", else %d", else_bb->index);
+
+ fprintf (dump_file, ", join %d\n", join_bb->index);
+ }
+
+ /* If the conditional jump is more than just a conditional
+ jump, then we can not do if-conversion on this block. */
+ jump = BB_END (test_bb);
+ if (! onlyjump_p (jump))
+ return FALSE;
+
+ /* If this is not a standard conditional jump, we can't parse it. */
+ cond = noce_get_condition (jump,
+ &cond_earliest,
+ then_else_reversed);
+ if (!cond)
+ return FALSE;
+
+ /* We must be comparing objects whose modes imply the size. */
+ if (GET_MODE (XEXP (cond, 0)) == BLKmode)
+ return FALSE;
+
+ /* Initialize an IF_INFO struct to pass around. */
+ memset (&if_info, 0, sizeof if_info);
+ if_info.test_bb = test_bb;
+ if_info.then_bb = then_bb;
+ if_info.else_bb = else_bb;
+ if_info.join_bb = join_bb;
+ if_info.cond = cond;
+ if_info.cond_earliest = cond_earliest;
+ if_info.jump = jump;
+ if_info.then_else_reversed = then_else_reversed;
+ if_info.branch_cost = BRANCH_COST (optimize_bb_for_speed_p (test_bb),
+ predictable_edge_p (then_edge));
+
+ /* Do the real work. */
+
+ if (noce_process_if_block (&if_info))
+ return TRUE;
+
+ if (HAVE_conditional_move
+ && cond_move_process_if_block (&if_info))
+ return TRUE;
+
+ return FALSE;
+}
+\f
+
+/* Merge the blocks and mark for local life update. */
+
+static void
+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 */
/* All block merging is done into the lower block numbers. */
combo_bb = test_bb;
+ df_set_bb_dirty (test_bb);
/* Merge any basic blocks to handle && and || subtests. Each of
the blocks are on the fallthru path from the predecessor block. */
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);
merge_blocks (combo_bb, then_bb);
num_true_changes++;
}
/* The outgoing edge for the current COMBO block should already
be correct. Verify this. */
if (EDGE_COUNT (combo_bb->succs) == 0)
- {
- if (find_reg_note (last, REG_NORETURN, NULL))
- ;
- else if (NONJUMP_INSN_P (last)
- && GET_CODE (PATTERN (last)) == TRAP_IF
- && TRAP_CONDITION (PATTERN (last)) == const_true_rtx)
- ;
- else
- abort ();
- }
+ gcc_assert (find_reg_note (last, REG_NORETURN, NULL)
+ || (NONJUMP_INSN_P (last)
+ && GET_CODE (PATTERN (last)) == TRAP_IF
+ && (TRAP_CONDITION (PATTERN (last))
+ == const_true_rtx)));
+ else
/* There should still be something at the end of the THEN or ELSE
blocks taking us to our final destination. */
- else if (JUMP_P (last))
- ;
- else if (EDGE_SUCC (combo_bb, 0)->dest == EXIT_BLOCK_PTR
- && CALL_P (last)
- && SIBLING_CALL_P (last))
- ;
- else if ((EDGE_SUCC (combo_bb, 0)->flags & EDGE_EH)
- && can_throw_internal (last))
- ;
- else
- abort ();
+ gcc_assert (JUMP_P (last)
+ || (EDGE_SUCC (combo_bb, 0)->dest == EXIT_BLOCK_PTR
+ && CALL_P (last)
+ && SIBLING_CALL_P (last))
+ || ((EDGE_SUCC (combo_bb, 0)->flags & EDGE_EH)
+ && can_throw_internal (last)));
}
/* The JOIN block may have had quite a number of other predecessors too.
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
- back up (as with a call to abort). */
+ back up (as with a call to a non-return function). */
else if (EDGE_COUNT (join_bb->preds) < 2
&& 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);
-
+ /* We can merge the JOIN cleanly and update the dataflow try
+ again on this pass.*/
merge_blocks (combo_bb, join_bb);
num_true_changes++;
}
/* The outgoing edge for the current COMBO block should already
be correct. Verify this. */
- if (EDGE_COUNT (combo_bb->succs) > 1
- || EDGE_SUCC (combo_bb, 0)->dest != join_bb)
- abort ();
+ gcc_assert (single_succ_p (combo_bb)
+ && single_succ (combo_bb) == join_bb);
/* Remove the jump and cruft from the end of the COMBO block. */
if (join_bb != EXIT_BLOCK_PTR)
- tidy_fallthru_edge (EDGE_SUCC (combo_bb, 0));
+ tidy_fallthru_edge (single_succ_edge (combo_bb));
}
num_updated_if_blocks++;
then_edge = EDGE_SUCC (test_bb, 0);
else_edge = EDGE_SUCC (test_bb, 1);
+ if (df_get_bb_dirty (then_edge->dest))
+ return NULL;
+ if (df_get_bb_dirty (else_edge->dest))
+ return NULL;
+
/* Neither edge should be abnormal. */
if ((then_edge->flags & EDGE_COMPLEX)
|| (else_edge->flags & EDGE_COMPLEX))
IFCVT_INIT_EXTRA_FIELDS (&ce_info);
#endif
- if (find_if_block (&ce_info))
+ if (! reload_completed
+ && noce_find_if_block (test_bb, then_edge, else_edge, pass))
+ goto success;
+
+ if (HAVE_conditional_execution && reload_completed
+ && cond_exec_find_if_block (&ce_info))
goto success;
- if (HAVE_trap && HAVE_conditional_trap
+ if (HAVE_trap
+ && optab_handler (ctrap_optab, word_mode)->insn_code != CODE_FOR_nothing
&& find_cond_trap (test_bb, then_edge, else_edge))
goto success;
- if (dom_computed[CDI_POST_DOMINATORS] >= DOM_NO_FAST_QUERY
+ if (dom_info_state (CDI_POST_DOMINATORS) >= DOM_NO_FAST_QUERY
&& (! HAVE_conditional_execution || reload_completed))
{
if (find_if_case_1 (test_bb, then_edge, else_edge))
success:
if (dump_file)
fprintf (dump_file, "Conversion succeeded on pass %d.\n", pass);
+ /* Set this so we continue looking. */
+ cond_exec_changed_p = TRUE;
return ce_info.test_bb;
}
if (INSN_P (insn)
&& !JUMP_P (insn)
+ && !DEBUG_INSN_P (insn)
&& GET_CODE (PATTERN (insn)) != USE
&& GET_CODE (PATTERN (insn)) != CLOBBER)
n_insns++;
Return TRUE if we were successful at converting the block. */
static int
-find_if_block (struct ce_if_block * ce_info)
+cond_exec_find_if_block (struct ce_if_block * ce_info)
{
basic_block test_bb = ce_info->test_bb;
basic_block then_bb = ce_info->then_bb;
ce_info->last_test_bb = test_bb;
+ /* We only ever should get here after reload,
+ and only if we have conditional execution. */
+ gcc_assert (HAVE_conditional_execution && reload_completed);
+
/* 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
- && EDGE_COUNT (test_bb->preds) == 1
- && EDGE_PRED (test_bb, 0)->flags == EDGE_FALLTHRU)
+ if (single_pred_p (test_bb)
+ && single_pred_edge (test_bb)->flags == EDGE_FALLTHRU)
{
- basic_block bb = EDGE_PRED (test_bb, 0)->src;
+ basic_block bb = single_pred (test_bb);
basic_block target_bb;
int max_insns = MAX_CONDITIONAL_EXECUTE;
int n_insns;
total_insns += n_insns;
blocks++;
- if (EDGE_COUNT (bb->preds) != 1)
+ if (!single_pred_p (bb))
break;
- bb = EDGE_PRED (bb, 0)->src;
+ bb = single_pred (bb);
n_insns = block_jumps_and_fallthru_p (bb, target_bb);
}
while (n_insns >= 0 && (total_insns + n_insns) <= max_insns);
other than any || blocks which jump to the THEN block. */
if ((EDGE_COUNT (then_bb->preds) - ce_info->num_or_or_blocks) != 1)
return FALSE;
-
+
/* The edges of the THEN and ELSE blocks cannot have complex edges. */
FOR_EACH_EDGE (cur_edge, ei, then_bb->preds)
{
/* The THEN block of an IF-THEN combo must have zero or one successors. */
if (EDGE_COUNT (then_bb->succs) > 0
- && (EDGE_COUNT (then_bb->succs) > 1
- || (EDGE_SUCC (then_bb, 0)->flags & EDGE_COMPLEX)
- || (flow2_completed && tablejump_p (BB_END (then_bb), NULL, NULL))))
+ && (!single_succ_p (then_bb)
+ || (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
+ || (epilogue_completed && tablejump_p (BB_END (then_bb), NULL, NULL))))
return FALSE;
/* If the THEN block has no successors, conditional execution can still
code processing. ??? we should fix this in the future. */
if (EDGE_COUNT (then_bb->succs) == 0)
{
- if (EDGE_COUNT (else_bb->preds) == 1)
+ if (single_pred_p (else_bb))
{
rtx last_insn = BB_END (then_bb);
/* If the THEN block's successor is the other edge out of the TEST block,
then we have an IF-THEN combo without an ELSE. */
- else if (EDGE_SUCC (then_bb, 0)->dest == else_bb)
+ else if (single_succ (then_bb) == else_bb)
{
join_bb = else_bb;
else_bb = NULL_BLOCK;
/* If the THEN and ELSE block meet in a subsequent block, and the ELSE
has exactly one predecessor and one successor, and the outgoing edge
is not complex, then we have an IF-THEN-ELSE combo. */
- else if (EDGE_COUNT (else_bb->succs) == 1
- && EDGE_SUCC (then_bb, 0)->dest == EDGE_SUCC (else_bb, 0)->dest
- && EDGE_COUNT (else_bb->preds) == 1
- && ! (EDGE_SUCC (else_bb, 0)->flags & EDGE_COMPLEX)
- && ! (flow2_completed && tablejump_p (BB_END (else_bb), NULL, NULL)))
- join_bb = EDGE_SUCC (else_bb, 0)->dest;
+ else if (single_succ_p (else_bb)
+ && single_succ (then_bb) == single_succ (else_bb)
+ && single_pred_p (else_bb)
+ && ! (single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
+ && ! (epilogue_completed && tablejump_p (BB_END (else_bb), NULL, NULL)))
+ join_bb = single_succ (else_bb);
/* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination. */
else
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
+ BLOCK notes, if by no other means than backing out the merge if they
exist. Sticky enough I don't want to think about it now. */
next = then_bb;
if (else_bb && (next = next->next_bb) != else_bb)
}
/* Do the real work. */
+
ce_info->else_bb = else_bb;
ce_info->join_bb = join_bb;
- return process_if_block (ce_info);
+ /* 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;
}
/* Convert a branch over a trap, or a branch
/* If this is not a standard conditional jump, we can't parse it. */
jump = BB_END (test_bb);
- cond = noce_get_condition (jump, &cond_earliest);
+ cond = noce_get_condition (jump, &cond_earliest, false);
if (! cond)
return FALSE;
}
/* Attempt to generate the conditional trap. */
- seq = gen_cond_trap (code, XEXP (cond, 0),
- XEXP (cond, 1),
+ seq = gen_cond_trap (code, copy_rtx (XEXP (cond, 0)),
+ copy_rtx (XEXP (cond, 1)),
TRAP_CODE (PATTERN (trap)));
if (seq == NULL)
return FALSE;
- num_true_changes++;
-
/* 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 (EDGE_COUNT (trap_bb->preds) == 0)
- delete_basic_block (trap_bb);
+ df_set_bb_dirty (test_bb);
+ df_set_bb_dirty (then_bb);
+ df_set_bb_dirty (else_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)
+ if (EDGE_COUNT (trap_bb->preds) == 0)
{
- 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);
+ delete_basic_block (trap_bb);
+ num_true_changes++;
}
+
+ /* Wire together the blocks again. */
+ if (current_ir_type () == IR_RTL_CFGLAYOUT)
+ single_succ_edge (test_bb)->flags |= EDGE_FALLTHRU;
else
{
rtx lab, newjump;
LABEL_NUSES (lab) += 1;
JUMP_LABEL (newjump) = lab;
emit_barrier_after (newjump);
+ }
+ delete_insn (jump);
- delete_insn (jump);
+ if (can_merge_blocks_p (test_bb, other_bb))
+ {
+ merge_blocks (test_bb, other_bb);
+ num_true_changes++;
}
+ num_updated_if_blocks++;
return TRUE;
}
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, new_bb;
- int then_bb_index, bb_cost;
+ basic_block else_bb = else_edge->dest;
+ basic_block new_bb;
+ int then_bb_index;
/* If we are partitioning hot/cold basic blocks, we don't want to
mess up unconditional or indirect jumps that cross between hot
and cold sections.
-
+
Basic block partitioning may result in some jumps that appear to
- be optimizable (or blocks that appear to be mergeable), but which really
- must be left untouched (they are required to make it safely across
- partition boundaries). See the comments at the top of
+ be optimizable (or blocks that appear to be mergeable), but which really
+ must be left untouched (they are required to make it safely across
+ partition boundaries). See the comments at the top of
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
- if (flag_reorder_blocks_and_partition
- && ((BB_END (then_bb)
- && find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
- || (BB_END (else_bb)
- && find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP,
- NULL_RTX))))
+ if ((BB_END (then_bb)
+ && find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
+ || (BB_END (test_bb)
+ && find_reg_note (BB_END (test_bb), REG_CROSSING_JUMP, NULL_RTX))
+ || (BB_END (else_bb)
+ && find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP,
+ NULL_RTX)))
return FALSE;
/* THEN has one successor. */
- if (EDGE_COUNT (then_bb->succs) != 1)
+ if (!single_succ_p (then_bb))
return FALSE;
/* THEN does not fall through, but is not strange either. */
- if (EDGE_SUCC (then_bb, 0)->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
+ if (single_succ_edge (then_bb)->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
return FALSE;
/* THEN has one predecessor. */
- if (EDGE_COUNT (then_bb->preds) != 1)
+ if (!single_pred_p (then_bb))
return FALSE;
/* THEN must do something. */
test_bb->index, then_bb->index);
/* THEN is small. */
- bb_cost = total_bb_rtx_cost (then_bb);
- if (bb_cost < 0 || bb_cost >= COSTS_N_INSNS (BRANCH_COST))
+ if (! cheap_bb_rtx_cost_p (then_bb,
+ COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge->src),
+ predictable_edge_p (then_edge)))))
return FALSE;
/* Registers set are dead, or are predicable. */
if (! dead_or_predicable (test_bb, then_bb, else_bb,
- EDGE_SUCC (then_bb, 0)->dest, 1))
+ single_succ (then_bb), 1))
return FALSE;
/* Conversion went ok, including moving the insns and fixing up the
jump. Adjust the CFG to match. */
- bitmap_ior (test_bb->global_live_at_end,
- else_bb->global_live_at_start,
- then_bb->global_live_at_end);
+ /* We can avoid creating a new basic block if then_bb is immediately
+ followed by else_bb, i.e. deleting then_bb allows test_bb to fall
+ thru to else_bb. */
+
+ if (then_bb->next_bb == else_bb
+ && then_bb->prev_bb == test_bb
+ && else_bb != EXIT_BLOCK_PTR)
+ {
+ redirect_edge_succ (FALLTHRU_EDGE (test_bb), else_bb);
+ new_bb = 0;
+ }
+ else
+ new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb),
+ else_bb);
+
+ df_set_bb_dirty (test_bb);
+ df_set_bb_dirty (else_bb);
- new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb);
then_bb_index = then_bb->index;
delete_basic_block (then_bb);
block we removed. */
if (new_bb)
{
- new_bb->index = then_bb_index;
- BASIC_BLOCK (then_bb_index) = new_bb;
+ df_bb_replace (then_bb_index, new_bb);
/* Since the fallthru edge was redirected from test_bb to new_bb,
we need to ensure that new_bb is in the same partition as
test bb (you can not fall through across section boundaries). */
BB_COPY_PARTITION (new_bb, test_bb);
}
- /* We've possibly created jump to next insn, cleanup_cfg will solve that
- later. */
num_true_changes++;
num_updated_if_blocks++;
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest;
edge else_succ;
- int bb_cost;
rtx note;
/* If we are partitioning hot/cold basic blocks, we don't want to
mess up unconditional or indirect jumps that cross between hot
and cold sections.
-
+
Basic block partitioning may result in some jumps that appear to
- be optimizable (or blocks that appear to be mergeable), but which really
- must be left untouched (they are required to make it safely across
- partition boundaries). See the comments at the top of
+ be optimizable (or blocks that appear to be mergeable), but which really
+ must be left untouched (they are required to make it safely across
+ partition boundaries). See the comments at the top of
bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
- if (flag_reorder_blocks_and_partition
- && ((BB_END (then_bb)
- && find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
- || (BB_END (else_bb)
- && find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP,
- NULL_RTX))))
+ if ((BB_END (then_bb)
+ && find_reg_note (BB_END (then_bb), REG_CROSSING_JUMP, NULL_RTX))
+ || (BB_END (test_bb)
+ && find_reg_note (BB_END (test_bb), REG_CROSSING_JUMP, NULL_RTX))
+ || (BB_END (else_bb)
+ && find_reg_note (BB_END (else_bb), REG_CROSSING_JUMP,
+ NULL_RTX)))
return FALSE;
/* ELSE has one successor. */
- if (EDGE_COUNT (else_bb->succs) != 1)
+ if (!single_succ_p (else_bb))
return FALSE;
else
- else_succ = EDGE_SUCC (else_bb, 0);
+ else_succ = single_succ_edge (else_bb);
/* ELSE outgoing edge is not complex. */
if (else_succ->flags & EDGE_COMPLEX)
return FALSE;
/* ELSE has one predecessor. */
- if (EDGE_COUNT (else_bb->preds) != 1)
+ if (!single_pred_p (else_bb))
return FALSE;
/* THEN is not EXIT. */
- if (then_bb->index < 0)
+ if (then_bb->index < NUM_FIXED_BLOCKS)
return FALSE;
/* ELSE is predicted or SUCC(ELSE) postdominates THEN. */
note = find_reg_note (BB_END (test_bb), REG_BR_PROB, NULL_RTX);
if (note && INTVAL (XEXP (note, 0)) >= REG_BR_PROB_BASE / 2)
;
- else if (else_succ->dest->index < 0
+ else if (else_succ->dest->index < NUM_FIXED_BLOCKS
|| dominated_by_p (CDI_POST_DOMINATORS, then_bb,
else_succ->dest))
;
test_bb->index, else_bb->index);
/* ELSE is small. */
- bb_cost = total_bb_rtx_cost (else_bb);
- if (bb_cost < 0 || bb_cost >= COSTS_N_INSNS (BRANCH_COST))
+ if (! cheap_bb_rtx_cost_p (else_bb,
+ COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge->src),
+ predictable_edge_p (else_edge)))))
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. */
- bitmap_ior (test_bb->global_live_at_end,
- then_bb->global_live_at_start,
- else_bb->global_live_at_end);
-
+ df_set_bb_dirty (test_bb);
+ df_set_bb_dirty (then_bb);
delete_basic_block (else_bb);
num_true_changes++;
basic_block other_bb, basic_block new_dest, int reversep)
{
rtx head, end, jump, earliest = NULL_RTX, old_dest, new_label = NULL_RTX;
+ /* Number of pending changes. */
+ int n_validated_changes = 0;
jump = BB_END (test_bb);
head = BB_HEAD (merge_bb);
end = BB_END (merge_bb);
+ while (DEBUG_INSN_P (end) && end != head)
+ end = PREV_INSN (end);
+
+ /* If merge_bb ends with a tablejump, predicating/moving insn's
+ into test_bb and then deleting merge_bb will result in the jumptable
+ that follows merge_bb being removed along with merge_bb and then we
+ get an unresolved reference to the jumptable. */
+ if (tablejump_p (end, NULL, NULL))
+ return FALSE;
+
if (LABEL_P (head))
head = NEXT_INSN (head);
+ while (DEBUG_INSN_P (head) && head != end)
+ head = NEXT_INSN (head);
if (NOTE_P (head))
{
if (head == end)
goto no_body;
}
head = NEXT_INSN (head);
+ while (DEBUG_INSN_P (head) && head != end)
+ head = NEXT_INSN (head);
}
if (JUMP_P (end))
goto no_body;
}
end = PREV_INSN (end);
+ while (DEBUG_INSN_P (end) && end != head)
+ end = PREV_INSN (end);
}
/* Disable handling dead code by conditional execution if the machine needs
prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
}
- if (! cond_exec_process_insns ((ce_if_block_t *)0, head, end, cond,
- prob_val, 0))
- goto cancel;
+ if (cond_exec_process_insns (NULL, head, end, cond, prob_val, 0)
+ && verify_changes (0))
+ n_validated_changes = num_validated_changes ();
+ else
+ cancel_changes (0);
earliest = jump;
}
- else
#endif
+ /* Try the NCE path if the CE path did not result in any changes. */
+ if (n_validated_changes == 0)
{
/* In the non-conditional execution case, we have to verify that there
are no trapping operations, no calls, no references to memory, and
that any registers modified are dead at the branch site. */
rtx insn, cond, prev;
- regset merge_set, tmp, test_live, test_set;
- struct propagate_block_info *pbi;
+ bitmap merge_set, test_live, test_set;
unsigned i, fail = 0;
bitmap_iterator bi;
{
if (CALL_P (insn))
return FALSE;
- if (INSN_P (insn))
+ if (NONDEBUG_INSN_P (insn))
{
if (may_trap_p (PATTERN (insn)))
return FALSE;
return FALSE;
/* Find the extent of the conditional. */
- cond = noce_get_condition (jump, &earliest);
+ cond = noce_get_condition (jump, &earliest, false);
if (! cond)
return FALSE;
TEST_SET = set of registers set between EARLIEST and the
end of the block. */
- tmp = OBSTACK_ALLOC_REG_SET (®_obstack);
- merge_set = OBSTACK_ALLOC_REG_SET (®_obstack);
- test_live = OBSTACK_ALLOC_REG_SET (®_obstack);
- test_set = OBSTACK_ALLOC_REG_SET (®_obstack);
+ merge_set = BITMAP_ALLOC (®_obstack);
+ test_live = BITMAP_ALLOC (®_obstack);
+ test_set = BITMAP_ALLOC (®_obstack);
/* ??? bb->local_set is only valid during calculate_global_regs_live,
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, merge_set, 0);
+ /* If we allocated new pseudos (e.g. in the conditional move
+ expander called from noce_emit_cmove), we must resize the
+ array first. */
+ if (max_regno < max_reg_num ())
+ max_regno = max_reg_num ();
+
+ FOR_BB_INSNS (merge_bb, insn)
+ {
+ if (NONDEBUG_INSN_P (insn))
+ {
+ unsigned int uid = INSN_UID (insn);
+ df_ref *def_rec;
+ for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ bitmap_set_bit (merge_set, DF_REF_REGNO (def));
+ }
+ }
+ }
/* For small register class machines, don't lengthen lifetimes of
hard registers before reload. */
fail = 1;
}
}
-
+
/* For TEST, we're interested in a range of insns, not a whole block.
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, test_set,
- 0);
-
+
+ /* The loop below takes the set of live registers
+ after JUMP, and calculates the live set before EARLIEST. */
+ bitmap_copy (test_live, df_get_live_in (other_bb));
+ df_simulate_initialize_backwards (test_bb, test_live);
for (insn = jump; ; insn = prev)
{
- prev = propagate_one_insn (pbi, insn);
+ if (INSN_P (insn))
+ {
+ df_simulate_find_defs (insn, test_set);
+ df_simulate_one_insn_backwards (test_bb, insn, test_live);
+ }
+ prev = PREV_INSN (insn);
if (insn == earliest)
break;
}
- free_propagate_block_info (pbi);
-
/* We can perform the transformation if
MERGE_SET & (TEST_SET | TEST_LIVE)
and
- TEST_SET & merge_bb->global_live_at_start
+ TEST_SET & DF_LIVE_IN (merge_bb)
are empty. */
if (bitmap_intersect_p (test_set, merge_set)
|| bitmap_intersect_p (test_live, merge_set)
- || bitmap_intersect_p (test_set, merge_bb->global_live_at_start))
+ || bitmap_intersect_p (test_set, df_get_live_in (merge_bb)))
fail = 1;
- FREE_REG_SET (tmp);
- FREE_REG_SET (merge_set);
- FREE_REG_SET (test_live);
- FREE_REG_SET (test_set);
+ BITMAP_FREE (merge_set);
+ BITMAP_FREE (test_live);
+ BITMAP_FREE (test_set);
if (fail)
return FALSE;
goto cancel;
}
- if (! apply_change_group ())
- return FALSE;
+ if (verify_changes (n_validated_changes))
+ confirm_change_group ();
+ else
+ goto cancel;
if (other_bb != new_dest)
{
- 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_jump_2 (jump, old_dest, new_label, 0, reversep);
redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
if (reversep)
/* Move the insns out of MERGE_BB to before the branch. */
if (head != NULL)
{
+ rtx insn;
+
if (end == BB_END (merge_bb))
BB_END (merge_bb) = PREV_INSN (head);
- if (squeeze_notes (&head, &end))
- return TRUE;
+ /* PR 21767: When moving insns above a conditional branch, REG_EQUAL
+ notes might become invalid. */
+ insn = head;
+ do
+ {
+ rtx note, set;
+
+ if (! INSN_P (insn))
+ continue;
+ note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
+ if (! note)
+ continue;
+ set = single_set (insn);
+ if (!set || !function_invariant_p (SET_SRC (set)))
+ remove_note (insn, note);
+ } while (insn != end && (insn = NEXT_INSN (insn)));
reorder_insns (head, end, PREV_INSN (earliest));
}
\f
/* Main entry point for all if-conversion. */
-void
-if_convert (int x_life_data_ok)
+static void
+if_convert (void)
{
basic_block bb;
int pass;
+ if (optimize == 1)
+ {
+ df_live_add_problem ();
+ df_live_set_all_dirty ();
+ }
+
num_possible_if_blocks = 0;
num_updated_if_blocks = 0;
num_true_changes = 0;
- life_data_ok = (x_life_data_ok != 0);
- if ((! targetm.cannot_modify_jumps_p ())
- && (!flag_reorder_blocks_and_partition || !no_new_pseudos
- || !targetm.have_named_sections))
- mark_loop_exit_edges ();
+ loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
+ mark_loop_exit_edges ();
+ loop_optimizer_finalize ();
+ free_dominance_info (CDI_DOMINATORS);
- /* Compute postdominators if we think we'll use them. */
- if (HAVE_conditional_execution || life_data_ok)
- calculate_dominance_info (CDI_POST_DOMINATORS);
+ /* Compute postdominators. */
+ calculate_dominance_info (CDI_POST_DOMINATORS);
- if (life_data_ok)
- clear_bb_flags ();
+ df_set_flags (DF_LR_RUN_DCE);
/* 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
pass = 0;
do
{
+ df_analyze ();
+ /* Only need to do dce on the first pass. */
+ df_clear_flags (DF_LR_RUN_DCE);
cond_exec_changed_p = FALSE;
pass++;
FOR_EACH_BB (bb)
{
- basic_block new_bb;
- while ((new_bb = find_if_header (bb, pass)))
- bb = new_bb;
+ basic_block new_bb;
+ while (!df_get_bb_dirty (bb)
+ && (new_bb = find_if_header (bb, pass)) != NULL)
+ bb = new_bb;
}
#ifdef IFCVT_MULTIPLE_DUMPS
clear_aux_for_blocks ();
- /* Rebuild life info for basic blocks that require it. */
- if (num_true_changes && life_data_ok)
- {
- /* 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);
- }
- update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES,
- PROP_DEATH_NOTES | PROP_SCAN_DEAD_CODE
- | PROP_KILL_DEAD_CODE);
- }
+ /* If we allocated new pseudos, we must resize the array for sched1. */
+ if (max_regno < max_reg_num ())
+ max_regno = max_reg_num ();
/* Write the final stats. */
if (dump_file && num_possible_if_blocks > 0)
num_true_changes);
}
+ if (optimize == 1)
+ df_remove_problem (df_live);
+
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
}
+\f
+static bool
+gate_handle_if_conversion (void)
+{
+ return (optimize > 0)
+ && dbg_cnt (if_conversion);
+}
+
+/* If-conversion and CFG cleanup. */
+static unsigned int
+rest_of_handle_if_conversion (void)
+{
+ if (flag_if_conversion)
+ {
+ if (dump_file)
+ dump_flow_info (dump_file, dump_flags);
+ cleanup_cfg (CLEANUP_EXPENSIVE);
+ if_convert ();
+ }
+
+ cleanup_cfg (0);
+ return 0;
+}
+
+struct rtl_opt_pass pass_rtl_ifcvt =
+{
+ {
+ RTL_PASS,
+ "ce1", /* name */
+ gate_handle_if_conversion, /* gate */
+ rest_of_handle_if_conversion, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_IFCVT, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_finish | TODO_verify_rtl_sharing |
+ TODO_dump_func /* todo_flags_finish */
+ }
+};
+
+static bool
+gate_handle_if_after_combine (void)
+{
+ return optimize > 0 && flag_if_conversion
+ && dbg_cnt (if_after_combine);
+}
+
+
+/* Rerun if-conversion, as combine may have simplified things enough
+ to now meet sequence length restrictions. */
+static unsigned int
+rest_of_handle_if_after_combine (void)
+{
+ if_convert ();
+ return 0;
+}
+
+struct rtl_opt_pass pass_if_after_combine =
+{
+ {
+ RTL_PASS,
+ "ce2", /* name */
+ gate_handle_if_after_combine, /* gate */
+ rest_of_handle_if_after_combine, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_IFCVT, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_finish | TODO_verify_rtl_sharing |
+ TODO_dump_func |
+ TODO_ggc_collect /* todo_flags_finish */
+ }
+};
+
+
+static bool
+gate_handle_if_after_reload (void)
+{
+ return optimize > 0 && flag_if_conversion2
+ && dbg_cnt (if_after_reload);
+}
+
+static unsigned int
+rest_of_handle_if_after_reload (void)
+{
+ if_convert ();
+ return 0;
+}
+
+
+struct rtl_opt_pass pass_if_after_reload =
+{
+ {
+ RTL_PASS,
+ "ce3", /* name */
+ gate_handle_if_after_reload, /* gate */
+ rest_of_handle_if_after_reload, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_IFCVT2, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_finish | TODO_verify_rtl_sharing |
+ TODO_dump_func |
+ TODO_ggc_collect /* todo_flags_finish */
+ }
+};
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