/* If-conversion support.
- Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010
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, 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.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 "df.h"
#include "vec.h"
#include "vecprim.h"
+#include "dbgcnt.h"
-#ifndef HAVE_conditional_execution
-#define HAVE_conditional_execution 0
-#endif
#ifndef HAVE_conditional_move
#define HAVE_conditional_move 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)
+#define MAX_CONDITIONAL_EXECUTE \
+ (BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
+ + 1)
#endif
#define IFCVT_MULTIPLE_DUMPS 1
static int cond_exec_changed_p;
/* Forward references. */
-static int count_bb_insns (basic_block);
-static bool cheap_bb_rtx_cost_p (basic_block, int);
+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 rtx noce_get_condition (rtx, rtx *, bool);
-static int noce_operand_ok (rtx);
+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);
/* 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);
false if the cost of any instruction could not be estimated. */
static bool
-cheap_bb_rtx_cost_p (basic_block bb, int max_cost)
+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 false;
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;
gcc_assert(NONJUMP_INSN_P (insn) || CALL_P (insn));
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;
+ rtx then_last_head = NULL_RTX; /* Last match at the head of THEN */
+ rtx else_last_head = NULL_RTX; /* Last match at the head of ELSE */
+ rtx then_first_tail = NULL_RTX; /* First match at the tail of THEN */
+ rtx else_first_tail = NULL_RTX; /* First match at the tail of ELSE */
+ int then_n_insns, else_n_insns, n_insns;
enum rtx_code false_code;
/* If test is comprised of && or || elements, and we've failed at handling
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);
+ then_n_insns = ce_info->num_then_insns = count_bb_insns (then_bb);
+ n_insns = then_n_insns;
max = MAX_CONDITIONAL_EXECUTE;
if (else_bb)
{
+ int n_matching;
+
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);
+ else_n_insns = ce_info->num_else_insns = count_bb_insns (else_bb);
+ n_insns += else_n_insns;
+
+ /* Look for matching sequences at the head and tail of the two blocks,
+ and limit the range of insns to be converted if possible. */
+ n_matching = flow_find_cross_jump (then_bb, else_bb,
+ &then_first_tail, &else_first_tail);
+ if (then_first_tail == BB_HEAD (then_bb))
+ then_start = then_end = NULL_RTX;
+ if (else_first_tail == BB_HEAD (else_bb))
+ else_start = else_end = NULL_RTX;
+
+ if (n_matching > 0)
+ {
+ if (then_end)
+ then_end = prev_active_insn (then_first_tail);
+ if (else_end)
+ else_end = prev_active_insn (else_first_tail);
+ n_insns -= 2 * n_matching;
+ }
+
+ if (then_start && else_start)
+ {
+ int longest_match = MIN (then_n_insns - n_matching,
+ else_n_insns - n_matching);
+ n_matching
+ = flow_find_head_matching_sequence (then_bb, else_bb,
+ &then_last_head,
+ &else_last_head,
+ longest_match);
+
+ if (n_matching > 0)
+ {
+ rtx insn;
+
+ /* We won't pass the insns in the head sequence to
+ cond_exec_process_insns, so we need to test them here
+ to make sure that they don't clobber the condition. */
+ for (insn = BB_HEAD (then_bb);
+ insn != NEXT_INSN (then_last_head);
+ insn = NEXT_INSN (insn))
+ if (!LABEL_P (insn) && !NOTE_P (insn)
+ && !DEBUG_INSN_P (insn)
+ && modified_in_p (test_expr, insn))
+ return FALSE;
+ }
+
+ if (then_last_head == then_end)
+ then_start = then_end = NULL_RTX;
+ if (else_last_head == else_end)
+ else_start = else_end = NULL_RTX;
+
+ if (n_matching > 0)
+ {
+ if (then_start)
+ then_start = next_active_insn (then_last_head);
+ if (else_start)
+ else_start = next_active_insn (else_last_head);
+ n_insns -= 2 * n_matching;
+ }
+ }
}
if (n_insns > max)
fprintf (dump_file, "%d insn%s converted to conditional execution.\n",
n_insns, (n_insns == 1) ? " was" : "s were");
- /* Merge the blocks! */
+ /* Merge the blocks! If we had matching sequences, make sure to delete one
+ copy at the appropriate location first: delete the copy in the THEN branch
+ for a tail sequence so that the remaining one is executed last for both
+ branches, and delete the copy in the ELSE branch for a head sequence so
+ that the remaining one is executed first for both branches. */
+ if (then_first_tail)
+ {
+ rtx from = then_first_tail;
+ if (!INSN_P (from))
+ from = next_active_insn (from);
+ delete_insn_chain (from, BB_END (then_bb), false);
+ }
+ if (else_last_head)
+ delete_insn_chain (first_active_insn (else_bb), else_last_head, false);
+
merge_if_block (ce_info);
cond_exec_changed_p = TRUE;
return TRUE;
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);
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 (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;
/* 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 ((BRANCH_COST >= 2
+ if ((if_info->branch_cost >= 2
|| STORE_FLAG_VALUE == -1)
&& ((if_info->a == const0_rtx
&& rtx_equal_p (if_info->b, if_info->x))
/* ??? FIXME: Magic number 5. */
if (cse_not_expected
&& MEM_P (a) && MEM_P (b)
- && BRANCH_COST >= 5)
+ && MEM_ADDR_SPACE (a) == MEM_ADDR_SPACE (b)
+ && if_info->branch_cost >= 5)
{
+ enum machine_mode address_mode
+ = targetm.addr_space.address_mode (MEM_ADDR_SPACE (a));
+
a = XEXP (a, 0);
b = XEXP (b, 0);
- x = gen_reg_rtx (Pmode);
+ x = gen_reg_rtx (address_mode);
is_mem = 1;
}
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
if (insn_b)
{
- insn_cost += insn_rtx_cost (PATTERN (insn_b));
- if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
+ 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;
}
set_mem_align (tmp,
MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
+ gcc_assert (MEM_ADDR_SPACE (if_info->a) == MEM_ADDR_SPACE (if_info->b));
+ set_mem_addr_space (tmp, MEM_ADDR_SPACE (if_info->a));
+
noce_emit_move_insn (if_info->x, tmp);
}
else if (target != x)
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);
/* First, look to see if we put a constant in a register. */
prev_insn = prev_nonnote_insn (if_info->cond_earliest);
if (prev_insn
+ && BLOCK_FOR_INSN (prev_insn)
+ == BLOCK_FOR_INSN (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);
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;
+
+ /* 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. The canonical
form is a branch around the negation, taken when the object is the
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;
{
rtx set, insn = prev_nonnote_insn (earliest);
if (insn
+ && BLOCK_FOR_INSN (insn) == BLOCK_FOR_INSN (earliest)
&& (set = single_set (insn))
&& rtx_equal_p (SET_DEST (set), c))
{
}
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;
- bool b_unconditional;
+ 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. The latter
- happens if INSN_B was taken from TEST_BB, or if there was no
- INSN_B which can happen for e.g. conditional stores to memory. */
- b_unconditional = (if_info->insn_b == NULL_RTX
- || BLOCK_FOR_INSN (if_info->insn_b) == if_info->test_bb);
- if (rtx_cost (t, SET) >= COSTS_N_INSNS (2)
- && (!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 ();
if (GET_CODE (cond) == ZERO_EXTRACT)
{
if (XEXP (cond, 1) != const1_rtx
- || GET_CODE (XEXP (cond, 2)) != CONST_INT
+ || !CONST_INT_P (XEXP (cond, 2))
|| ! rtx_equal_p (x, XEXP (cond, 0)))
return FALSE;
bitnum = INTVAL (XEXP (cond, 2));
{
/* Check for "if (X & C) x = x op C". */
if (! rtx_equal_p (x, XEXP (a, 0))
- || GET_CODE (XEXP (a, 1)) != CONST_INT
+ || !CONST_INT_P (XEXP (a, 1))
|| (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
!= (unsigned HOST_WIDE_INT) 1 << bitnum)
return FALSE;
{
/* Check for "if (X & C) x &= ~C". */
if (! rtx_equal_p (x, XEXP (a, 0))
- || GET_CODE (XEXP (a, 1)) != CONST_INT
+ || !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;
/* 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 true if a write into MEM may trap or fault. */
static bool
-noce_mem_write_may_trap_or_fault_p (rtx mem)
+noce_mem_write_may_trap_or_fault_p (const_rtx mem)
{
rtx addr;
addr = XEXP (addr, 1);
break;
case PLUS:
- if (GET_CODE (XEXP (addr, 1)) == CONST_INT)
+ if (CONST_INT_P (XEXP (addr, 1)))
addr = XEXP (addr, 0);
else
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. */
else
{
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_FOR_INSN (insn_b) != BLOCK_FOR_INSN (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;
}
the lifetime of hard registers on small register class machines. */
orig_x = x;
if (!REG_P (x)
- || (SMALL_REGISTER_CLASSES
- && REGNO (x) < FIRST_PSEUDO_REGISTER))
+ || (HARD_REGISTER_P (x)
+ && targetm.small_register_classes_for_mode_p (GET_MODE (x))))
{
if (GET_MODE (x) == BLKmode)
return FALSE;
- if (GET_MODE (x) == ZERO_EXTRACT
- && (GET_CODE (XEXP (x, 1)) != CONST_INT
- || GET_CODE (XEXP (x, 2)) != CONST_INT))
+ 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
if (! noce_operand_ok (a) || ! noce_operand_ok (b))
return FALSE;
+ retry:
/* Set up the info block for our subroutines. */
if_info->insn_a = insn_a;
if_info->insn_b = insn_b;
goto success;
}
- /* Disallow the "if (...) x = a;" form (with an 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 (!set_b && MEM_P (orig_x) && noce_mem_write_may_trap_or_fault_p (orig_x))
- return FALSE;
+ if (!set_b && MEM_P (orig_x))
+ {
+ /* 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))
goto success;
if (HAVE_conditional_move
&& noce_try_cmove (if_info))
goto success;
- if (! HAVE_conditional_execution)
+ if (! targetm.have_conditional_execution ())
{
if (noce_try_store_flag_constants (if_info))
goto success;
goto success;
}
+ if (!else_bb && set_b)
+ {
+ insn_b = set_b = NULL_RTX;
+ b = orig_x;
+ goto retry;
+ }
+
return FALSE;
success:
REGS. COND is the condition we will test. */
static int
-check_cond_move_block (basic_block bb, rtx *vals, VEC (int, heap) *regs, rtx cond)
+check_cond_move_block (basic_block bb, rtx *vals, VEC (int, heap) **regs,
+ rtx cond)
{
rtx insn;
{
rtx set, dest, src;
- if (!INSN_P (insn) || JUMP_P (insn))
+ if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
continue;
set = single_set (insn);
if (!set)
dest = SET_DEST (set);
src = SET_SRC (set);
if (!REG_P (dest)
- || (SMALL_REGISTER_CLASSES && HARD_REGISTER_P (dest)))
+ || (HARD_REGISTER_P (dest)
+ && targetm.small_register_classes_for_mode_p (GET_MODE (dest))))
return FALSE;
if (!CONSTANT_P (src) && !register_operand (src, VOIDmode))
vals[REGNO (dest)] = src;
- VEC_safe_push (int, heap, regs, REGNO (dest));
+ VEC_safe_push (int, heap, *regs, REGNO (dest));
}
return TRUE;
rtx set, target, dest, t, e;
unsigned int regno;
- if (!INSN_P (insn) || JUMP_P (insn))
+ /* ??? 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)));
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)))
- return FALSE;
+ 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
if (!CONSTANT_P (then_vals[reg])
&& !CONSTANT_P (else_vals[reg])
&& !rtx_equal_p (then_vals[reg], else_vals[reg]))
- return FALSE;
+ {
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
}
}
branches, since if we convert we are going to always execute
them. */
if (c > MAX_CONDITIONAL_EXECUTE)
- return FALSE;
+ {
+ 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. */
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)
- return FALSE;
+ {
+ VEC_free (int, heap, then_regs);
+ VEC_free (int, heap, else_regs);
+ return FALSE;
+ }
loc_insn = first_active_insn (then_bb);
if (!loc_insn)
VEC_free (int, heap, then_regs);
VEC_free (int, heap, else_regs);
-
return TRUE;
}
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,
+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. */
return FALSE;
/* If this is not a standard conditional jump, we can't parse it. */
- cond = noce_get_condition (jump,
- &if_info.cond_earliest,
- then_else_reversed);
+ cond = noce_get_condition (jump, &cond_earliest, then_else_reversed);
if (!cond)
return FALSE;
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. */
/* Otherwise this must be a multiway branch of some sort. */
return NULL;
- memset (&ce_info, '\0', sizeof (ce_info));
+ 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;
IFCVT_INIT_EXTRA_FIELDS (&ce_info);
#endif
- if (! reload_completed
+ if (!reload_completed
&& noce_find_if_block (test_bb, then_edge, else_edge, pass))
goto success;
- if (HAVE_conditional_execution && reload_completed
+ if (reload_completed
+ && targetm.have_conditional_execution ()
&& 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_info_state (CDI_POST_DOMINATORS) >= DOM_NO_FAST_QUERY
- && (! HAVE_conditional_execution || reload_completed))
+ && (reload_completed || !targetm.have_conditional_execution ()))
{
if (find_if_case_1 (test_bb, then_edge, else_edge))
goto success;
if (INSN_P (insn)
&& !JUMP_P (insn)
+ && !DEBUG_INSN_P (insn)
&& GET_CODE (PATTERN (insn)) != USE
&& GET_CODE (PATTERN (insn)) != CLOBBER)
n_insns++;
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);
+ and if we have conditional execution. */
+ gcc_assert (reload_completed && targetm.have_conditional_execution ());
/* 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
if (EDGE_COUNT (then_bb->succs) > 0
&& (!single_succ_p (then_bb)
|| (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
- || (epilogue_completed && tablejump_p (BB_END (then_bb), NULL, NULL))))
+ || (epilogue_completed
+ && tablejump_p (BB_END (then_bb), NULL, NULL))))
return FALSE;
/* If the THEN block has no successors, conditional execution can still
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)))
+ && !(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. */
}
/* 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;
test_bb->index, then_bb->index);
/* THEN is small. */
- if (! cheap_bb_rtx_cost_p (then_bb, 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. */
test_bb->index, else_bb->index);
/* ELSE is small. */
- if (! cheap_bb_rtx_cost_p (else_bb, 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. */
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
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
to do anything funny with the tests, etc. */
#ifndef IFCVT_MODIFY_TESTS
- if (HAVE_conditional_execution)
+ if (targetm.have_conditional_execution ())
{
/* In the conditional execution case, we have things easy. We know
the condition is reversible. We don't have to check life info
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;
- bitmap merge_set, test_live, test_set;
+ bitmap merge_set, merge_set_noclobber, 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;
/* Collect:
MERGE_SET = set of registers set in MERGE_BB
+ MERGE_SET_NOCLOBBER = like MERGE_SET, but only includes registers
+ that are really set, not just clobbered.
TEST_LIVE = set of registers live at EARLIEST
- TEST_SET = set of registers set between EARLIEST and the
- end of the block. */
+ TEST_SET = set of registers set between EARLIEST and the
+ end of the block. */
merge_set = BITMAP_ALLOC (®_obstack);
+ merge_set_noclobber = BITMAP_ALLOC (®_obstack);
test_live = BITMAP_ALLOC (®_obstack);
test_set = BITMAP_ALLOC (®_obstack);
FOR_BB_INSNS (merge_bb, insn)
{
- if (INSN_P (insn))
+ if (NONDEBUG_INSN_P (insn))
{
- unsigned int uid = INSN_UID (insn);
- struct df_ref **def_rec;
- for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
- {
- struct df_ref *def = *def_rec;
- bitmap_set_bit (merge_set, DF_REF_REGNO (def));
- }
+ df_simulate_find_defs (insn, merge_set);
+ df_simulate_find_noclobber_defs (insn, merge_set_noclobber);
}
}
/* For small register class machines, don't lengthen lifetimes of
hard registers before reload. */
- if (SMALL_REGISTER_CLASSES && ! reload_completed)
+ if (! reload_completed
+ && targetm.small_register_classes_for_mode_p (VOIDmode))
{
- EXECUTE_IF_SET_IN_BITMAP (merge_set, 0, i, bi)
+ EXECUTE_IF_SET_IN_BITMAP (merge_set_noclobber, 0, i, bi)
{
if (i < FIRST_PSEUDO_REGISTER
&& ! fixed_regs[i]
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. */
-
- /* The loop below takes the set of live registers
+
+ /* The loop below takes the set of live registers
after JUMP, and calculates the live set before EARLIEST. */
- bitmap_copy (test_live, DF_LIVE_IN (other_bb));
- df_simulate_artificial_refs_at_end (test_bb, test_live);
+ bitmap_copy (test_live, df_get_live_in (other_bb));
+ df_simulate_initialize_backwards (test_bb, test_live);
for (insn = jump; ; insn = prev)
{
if (INSN_P (insn))
}
/* We can perform the transformation if
- MERGE_SET & (TEST_SET | TEST_LIVE)
+ MERGE_SET_NOCLOBBER & TEST_SET
+ and
+ MERGE_SET & TEST_LIVE)
and
TEST_SET & DF_LIVE_IN (merge_bb)
are empty. */
- if (bitmap_intersect_p (test_set, merge_set)
+ if (bitmap_intersect_p (test_set, merge_set_noclobber)
|| bitmap_intersect_p (test_live, merge_set)
- || bitmap_intersect_p (test_set, DF_LIVE_IN (merge_bb)))
+ || bitmap_intersect_p (test_set, df_get_live_in (merge_bb)))
fail = 1;
+ BITMAP_FREE (merge_set_noclobber);
BITMAP_FREE (merge_set);
BITMAP_FREE (test_live);
BITMAP_FREE (test_set);
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 (! note)
continue;
set = single_set (insn);
- if (!set || !function_invariant_p (SET_SRC (set)))
+ if (!set || !function_invariant_p (SET_SRC (set))
+ || !function_invariant_p (XEXP (note, 0)))
remove_note (insn, note);
} while (insn != end && (insn = NEXT_INSN (insn)));
/* Main entry point for all if-conversion. */
static void
-if_convert (bool recompute_dominance)
+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;
- /* Some transformations in this pass can create new pseudos,
- if the pass runs before reload. Make sure we can do so. */
- gcc_assert (! no_new_pseudos || reload_completed);
-
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 || recompute_dominance)
- calculate_dominance_info (CDI_POST_DOMINATORS);
+ /* Compute postdominators. */
+ calculate_dominance_info (CDI_POST_DOMINATORS);
df_set_flags (DF_LR_RUN_DCE);
FOR_EACH_BB (bb)
{
basic_block new_bb;
- while (!df_get_bb_dirty (bb)
+ while (!df_get_bb_dirty (bb)
&& (new_bb = find_if_header (bb, pass)) != NULL)
bb = new_bb;
}
#ifdef IFCVT_MULTIPLE_DUMPS
if (dump_file && cond_exec_changed_p)
- print_rtl_with_bb (dump_file, get_insns ());
+ {
+ if (dump_flags & TDF_SLIM)
+ print_rtl_slim_with_bb (dump_file, get_insns (), dump_flags);
+ else
+ print_rtl_with_bb (dump_file, get_insns ());
+ }
#endif
}
while (cond_exec_changed_p);
num_true_changes);
}
+ if (optimize == 1)
+ df_remove_problem (df_live);
+
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
static bool
gate_handle_if_conversion (void)
{
- return (optimize > 0);
+ return (optimize > 0)
+ && dbg_cnt (if_conversion);
}
/* If-conversion and CFG cleanup. */
if (dump_file)
dump_flow_info (dump_file, dump_flags);
cleanup_cfg (CLEANUP_EXPENSIVE);
- if_convert (false);
+ if_convert ();
}
cleanup_cfg (0);
return 0;
}
-struct tree_opt_pass pass_rtl_ifcvt =
+struct rtl_opt_pass pass_rtl_ifcvt =
{
+ {
+ RTL_PASS,
"ce1", /* name */
gate_handle_if_conversion, /* gate */
rest_of_handle_if_conversion, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_df_finish |
- TODO_dump_func, /* todo_flags_finish */
- 'C' /* letter */
+ 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);
+ return optimize > 0 && flag_if_conversion
+ && dbg_cnt (if_after_combine);
}
static unsigned int
rest_of_handle_if_after_combine (void)
{
- no_new_pseudos = 0;
- if_convert (true);
- no_new_pseudos = 1;
+ if_convert ();
return 0;
}
-struct tree_opt_pass pass_if_after_combine =
+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 */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_df_finish |
+ TODO_df_finish | TODO_verify_rtl_sharing |
TODO_dump_func |
- TODO_ggc_collect, /* todo_flags_finish */
- 'C' /* letter */
+ TODO_ggc_collect /* todo_flags_finish */
+ }
};
static bool
gate_handle_if_after_reload (void)
{
- return (optimize > 0);
+ return optimize > 0 && flag_if_conversion2
+ && dbg_cnt (if_after_reload);
}
static unsigned int
rest_of_handle_if_after_reload (void)
{
- if (flag_if_conversion2)
- if_convert (true);
+ if_convert ();
return 0;
}
-struct tree_opt_pass pass_if_after_reload =
+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 */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_df_finish |
+ TODO_df_finish | TODO_verify_rtl_sharing |
TODO_dump_func |
- TODO_ggc_collect, /* todo_flags_finish */
- 'E' /* letter */
+ TODO_ggc_collect /* todo_flags_finish */
+ }
};