/* 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,
+ 2011
Free Software Foundation, Inc.
This file is part of GCC.
#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 "diagnostic-core.h"
#include "tm_p.h"
#include "cfgloop.h"
#include "target.h"
#include "tree-pass.h"
#include "df.h"
#include "vec.h"
+#include "pointer-set.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
/* Forward references. */
static int count_bb_insns (const_basic_block);
-static bool cheap_bb_rtx_cost_p (const_basic_block, int);
+static bool cheap_bb_rtx_cost_p (const_basic_block, int, int);
static rtx first_active_insn (basic_block);
static rtx last_active_insn (basic_block, int);
+static rtx find_active_insn_before (basic_block, rtx);
+static rtx find_active_insn_after (basic_block, rtx);
static basic_block block_fallthru (basic_block);
static int cond_exec_process_insns (ce_if_block_t *, rtx, rtx, rtx, rtx, int);
static rtx cond_exec_get_condition (rtx);
static int cond_exec_find_if_block (ce_if_block_t *);
static int find_if_case_1 (basic_block, edge, edge);
static int find_if_case_2 (basic_block, edge, edge);
-static int find_memory (rtx *, void *);
static int dead_or_predicable (basic_block, basic_block, basic_block,
- basic_block, int);
+ edge, int);
static void noce_emit_move_insn (rtx, rtx);
static rtx block_has_only_trap (basic_block);
\f
/* 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. */
+ false if the cost of any instruction could not be estimated.
+
+ The cost of the non-jump insns in BB is scaled by REG_BR_PROB_BASE
+ as those insns are being speculated. MAX_COST is scaled with SCALE
+ plus a small fudge factor. */
static bool
-cheap_bb_rtx_cost_p (const_basic_block bb, int max_cost)
+cheap_bb_rtx_cost_p (const_basic_block bb, int scale, int max_cost)
{
int count = 0;
rtx insn = BB_HEAD (bb);
+ bool speed = optimize_bb_for_speed_p (bb);
+
+ /* Our branch probability/scaling factors are just estimates and don't
+ account for cases where we can get speculation for free and other
+ secondary benefits. So we fudge the scale factor to make speculating
+ appear a little more profitable. */
+ scale += REG_BR_PROB_BASE / 8;
+ max_cost *= scale;
while (1)
{
if (NONJUMP_INSN_P (insn))
{
- int cost = insn_rtx_cost (PATTERN (insn));
+ int cost = insn_rtx_cost (PATTERN (insn), speed) * REG_BR_PROB_BASE;
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))
return insn;
}
+/* Return the active insn before INSN inside basic block CURR_BB. */
+
+static rtx
+find_active_insn_before (basic_block curr_bb, rtx insn)
+{
+ if (!insn || insn == BB_HEAD (curr_bb))
+ return NULL_RTX;
+
+ while ((insn = PREV_INSN (insn)) != NULL_RTX)
+ {
+ if (NONJUMP_INSN_P (insn) || JUMP_P (insn) || CALL_P (insn))
+ break;
+
+ /* No other active insn all the way to the start of the basic block. */
+ if (insn == BB_HEAD (curr_bb))
+ return NULL_RTX;
+ }
+
+ return insn;
+}
+
+/* Return the active insn after INSN inside basic block CURR_BB. */
+
+static rtx
+find_active_insn_after (basic_block curr_bb, rtx insn)
+{
+ if (!insn || insn == BB_END (curr_bb))
+ return NULL_RTX;
+
+ while ((insn = NEXT_INSN (insn)) != NULL_RTX)
+ {
+ if (NONJUMP_INSN_P (insn) || JUMP_P (insn) || CALL_P (insn))
+ break;
+
+ /* No other active insn all the way to the end of the basic block. */
+ if (insn == BB_END (curr_bb))
+ return NULL_RTX;
+ }
+
+ return insn;
+}
+
/* Return the basic block reached by falling though the basic block BB. */
static basic_block
block_fallthru (basic_block bb)
{
- edge e;
- edge_iterator ei;
-
- FOR_EACH_EDGE (e, ei, bb->succs)
- if (e->flags & EDGE_FALLTHRU)
- break;
+ edge e = find_fallthru_edge (bb->succs);
return (e) ? e->dest : NULL_BLOCK;
}
for (insn = start; ; insn = NEXT_INSN (insn))
{
- if (NOTE_P (insn))
+ /* dwarf2out can't cope with conditional prologues. */
+ if (NOTE_P (insn) && NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
+ return FALSE;
+
+ 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,
+ NULL);
+ 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 = find_active_insn_before (then_bb, then_first_tail);
+ if (else_end)
+ else_end = find_active_insn_before (else_bb, 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 = find_active_insn_after (then_bb, then_last_head);
+ if (else_start)
+ else_start = find_active_insn_after (else_bb, 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 = find_active_insn_after (then_bb, 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);
}
gcc_assert (start < (MEM_P (op) ? BITS_PER_UNIT : BITS_PER_WORD));
- store_bit_field (op, size, start, GET_MODE (x), y);
+ store_bit_field (op, size, start, 0, 0, GET_MODE (x), y);
return;
}
inner = XEXP (outer, 0);
outmode = GET_MODE (outer);
bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
- store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos, outmode, y);
+ store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos,
+ 0, 0, outmode, y);
}
/* Return sequence of instructions generated by if conversion. This
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))
noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code,
rtx cmp_a, rtx cmp_b, rtx vfalse, rtx vtrue)
{
+ rtx target ATTRIBUTE_UNUSED;
+ int unsignedp ATTRIBUTE_UNUSED;
+
/* If earliest == jump, try to build the cmove insn directly.
This is helpful when combine has created some complex condition
(like for alpha's cmovlbs) that we can't hope to regenerate
return NULL_RTX;
#if HAVE_conditional_move
- return emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
- vtrue, vfalse, GET_MODE (x),
- (code == LTU || code == GEU
- || code == LEU || code == GTU));
+ unsignedp = (code == LTU || code == GEU
+ || code == LEU || code == GTU);
+
+ target = emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
+ vtrue, vfalse, GET_MODE (x),
+ unsignedp);
+ if (target)
+ return target;
+
+ /* We might be faced with a situation like:
+
+ x = (reg:M TARGET)
+ vtrue = (subreg:M (reg:N VTRUE) BYTE)
+ vfalse = (subreg:M (reg:N VFALSE) BYTE)
+
+ We can't do a conditional move in mode M, but it's possible that we
+ could do a conditional move in mode N instead and take a subreg of
+ the result.
+
+ If we can't create new pseudos, though, don't bother. */
+ if (reload_completed)
+ return NULL_RTX;
+
+ if (GET_CODE (vtrue) == SUBREG && GET_CODE (vfalse) == SUBREG)
+ {
+ rtx reg_vtrue = SUBREG_REG (vtrue);
+ rtx reg_vfalse = SUBREG_REG (vfalse);
+ unsigned int byte_vtrue = SUBREG_BYTE (vtrue);
+ unsigned int byte_vfalse = SUBREG_BYTE (vfalse);
+ rtx promoted_target;
+
+ if (GET_MODE (reg_vtrue) != GET_MODE (reg_vfalse)
+ || byte_vtrue != byte_vfalse
+ || (SUBREG_PROMOTED_VAR_P (vtrue)
+ != SUBREG_PROMOTED_VAR_P (vfalse))
+ || (SUBREG_PROMOTED_UNSIGNED_P (vtrue)
+ != SUBREG_PROMOTED_UNSIGNED_P (vfalse)))
+ return NULL_RTX;
+
+ promoted_target = gen_reg_rtx (GET_MODE (reg_vtrue));
+
+ target = emit_conditional_move (promoted_target, code, cmp_a, cmp_b,
+ VOIDmode, reg_vtrue, reg_vfalse,
+ GET_MODE (reg_vtrue), unsignedp);
+ /* Nope, couldn't do it in that mode either. */
+ if (!target)
+ return NULL_RTX;
+
+ target = gen_rtx_SUBREG (GET_MODE (vtrue), promoted_target, byte_vtrue);
+ SUBREG_PROMOTED_VAR_P (target) = SUBREG_PROMOTED_VAR_P (vtrue);
+ SUBREG_PROMOTED_UNSIGNED_SET (target, SUBREG_PROMOTED_UNSIGNED_P (vtrue));
+ emit_move_insn (x, target);
+ return x;
+ }
+ else
+ return NULL_RTX;
#else
/* We'll never get here, as noce_process_if_block doesn't call the
functions involved. Ifdef code, however, should be discouraged
/* ??? 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;
}
/* ??? We could handle this if we knew that a load from A or B could
- not fault. This is also true if we've already loaded
+ not trap or fault. This is also true if we've already loaded
from the address along the path from ENTRY. */
- else if (may_trap_p (a) || may_trap_p (b))
+ else if (may_trap_or_fault_p (a) || may_trap_or_fault_p (b))
return FALSE;
/* if (test) x = a + b; else x = c - d;
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;
}
/* Copy over flags as appropriate. */
if (MEM_VOLATILE_P (if_info->a) || MEM_VOLATILE_P (if_info->b))
MEM_VOLATILE_P (tmp) = 1;
- if (MEM_IN_STRUCT_P (if_info->a) && MEM_IN_STRUCT_P (if_info->b))
- MEM_IN_STRUCT_P (tmp) = 1;
- if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b))
- MEM_SCALAR_P (tmp) = 1;
if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a));
set_mem_align (tmp,
MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
+ 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
+ || (set_src_cost (t, 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;
cond = XEXP (SET_SRC (set), 0);
tmp = XEXP (cond, 0);
- if (REG_P (tmp) && GET_MODE_CLASS (GET_MODE (tmp)) == MODE_INT)
+ if (REG_P (tmp) && GET_MODE_CLASS (GET_MODE (tmp)) == MODE_INT
+ && (GET_MODE (tmp) != BImode
+ || !targetm.small_register_classes_for_mode_p (BImode)))
{
*earliest = jump;
/* Otherwise, fall back on canonicalize_condition to do the dirty
work of manipulating MODE_CC values and COMPARE rtx codes. */
- return canonicalize_condition (jump, cond, reverse, earliest,
- NULL_RTX, false, true);
+ tmp = canonicalize_condition (jump, cond, reverse, earliest,
+ NULL_RTX, false, true);
+
+ /* We don't handle side-effects in the condition, like handling
+ REG_INC notes and making sure no duplicate conditions are emitted. */
+ if (tmp != NULL_RTX && side_effects_p (tmp))
+ return NULL_RTX;
+
+ return tmp;
}
/* Return true if OP is ok for if-then-else processing. */
static int
noce_operand_ok (const_rtx op)
{
+ if (side_effects_p (op))
+ return FALSE;
+
/* We special-case memories, so handle any of them with
no address side effects. */
if (MEM_P (op))
return ! side_effects_p (XEXP (op, 0));
- if (side_effects_p (op))
- return FALSE;
-
return ! may_trap_p (op);
}
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);
+ insn_b = prev_nonnote_nondebug_insn (if_info->cond_earliest);
/* We're going to be moving the evaluation of B down from above
COND_EARLIEST to JUMP. Make sure the relevant data is still
intact. */
if (! insn_b
+ || 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:
/* 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. */
+ register. For each assignment, store the value in the pointer map
+ VALS, keyed indexed by register pointer, then store the register
+ pointer in 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,
+ struct pointer_map_t *vals,
+ VEC (rtx, heap) **regs,
+ rtx cond)
{
rtx insn;
FOR_BB_INSNS (bb, insn)
{
rtx set, dest, src;
+ void **slot;
- 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))
/* Don't try to handle this if the source register was
modified earlier in the block. */
if ((REG_P (src)
- && vals[REGNO (src)] != NULL)
+ && pointer_map_contains (vals, src))
|| (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
- && vals[REGNO (SUBREG_REG (src))] != NULL))
+ && pointer_map_contains (vals, SUBREG_REG (src))))
return FALSE;
/* Don't try to handle this if the destination register was
modified earlier in the block. */
- if (vals[REGNO (dest)] != NULL)
+ if (pointer_map_contains (vals, dest))
return FALSE;
/* Don't try to handle this if the condition uses the
&& modified_between_p (src, insn, NEXT_INSN (BB_END (bb))))
return FALSE;
- vals[REGNO (dest)] = src;
+ slot = pointer_map_insert (vals, (void *) dest);
+ *slot = (void *) src;
- VEC_safe_push (int, heap, regs, REGNO (dest));
+ VEC_safe_push (rtx, heap, *regs, 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
+ a condition COND, and pointer maps 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,
+ struct pointer_map_t *then_vals,
+ struct pointer_map_t *else_vals,
bool else_block_p)
{
enum rtx_code code;
FOR_BB_INSNS (bb, insn)
{
rtx set, target, dest, t, e;
- unsigned int regno;
+ void **then_slot, **else_slot;
- 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)));
dest = SET_DEST (set);
- regno = REGNO (dest);
- t = then_vals[regno];
- e = else_vals[regno];
+ then_slot = pointer_map_contains (then_vals, dest);
+ else_slot = pointer_map_contains (else_vals, dest);
+ t = then_slot ? (rtx) *then_slot : NULL_RTX;
+ e = else_slot ? (rtx) *else_slot : NULL_RTX;
if (else_block_p)
{
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;
+ rtx reg;
+ int c;
+ struct pointer_map_t *then_vals;
+ struct pointer_map_t *else_vals;
+ VEC (rtx, heap) *then_regs = NULL;
+ VEC (rtx, heap) *else_regs = NULL;
unsigned int i;
+ int success_p = FALSE;
/* 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);
+ then_vals = pointer_map_create ();
+ else_vals = pointer_map_create ();
/* 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)))
+ goto done;
/* 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
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++)
+ FOR_EACH_VEC_ELT (rtx, then_regs, i, reg)
{
- if (!then_vals[reg] && !else_vals[reg])
- continue;
+ void **then_slot = pointer_map_contains (then_vals, reg);
+ void **else_slot = pointer_map_contains (else_vals, reg);
- if (!else_vals[reg])
+ gcc_checking_assert (then_slot);
+ if (!else_slot)
++c;
else
{
- if (!CONSTANT_P (then_vals[reg])
- && !CONSTANT_P (else_vals[reg])
- && !rtx_equal_p (then_vals[reg], else_vals[reg]))
- return FALSE;
+ rtx then_val = (rtx) *then_slot;
+ rtx else_val = (rtx) *else_slot;
+ if (!CONSTANT_P (then_val) && !CONSTANT_P (else_val)
+ && !rtx_equal_p (then_val, else_val))
+ goto done;
}
}
/* Finish off c for MAX_CONDITIONAL_EXECUTE. */
- for (i = 0; VEC_iterate (int, else_regs, i, reg); ++i)
- if (!then_vals[reg])
- ++c;
+ FOR_EACH_VEC_ELT (rtx, else_regs, i, reg)
+ {
+ gcc_checking_assert (pointer_map_contains (else_vals, reg));
+ if (!pointer_map_contains (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)
- return FALSE;
+ goto done;
/* 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 ();
- return FALSE;
+ goto done;
}
seq = end_ifcvt_sequence (if_info);
if (!seq)
- return FALSE;
+ goto done;
loc_insn = first_active_insn (then_bb);
if (!loc_insn)
num_updated_if_blocks++;
- VEC_free (int, heap, then_regs);
- VEC_free (int, heap, else_regs);
+ success_p = TRUE;
- return TRUE;
+done:
+ pointer_map_destroy (then_vals);
+ pointer_map_destroy (else_vals);
+ VEC_free (rtx, heap, then_regs);
+ VEC_free (rtx, heap, else_regs);
+ return success_p;
}
\f
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;
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);
+ cond = noce_get_condition (jump, &cond_earliest, then_else_reversed);
if (!cond)
return FALSE;
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) != 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. */
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest;
basic_block new_bb;
- int then_bb_index;
+ int then_bb_index, then_prob;
+ rtx else_target = NULL_RTX;
/* If we are partitioning hot/cold basic blocks, we don't want to
mess up unconditional or indirect jumps that cross between hot
"\nIF-CASE-1 found, start %d, then %d\n",
test_bb->index, then_bb->index);
- /* THEN is small. */
- if (! cheap_bb_rtx_cost_p (then_bb, COSTS_N_INSNS (BRANCH_COST)))
+ if (then_edge->probability)
+ then_prob = REG_BR_PROB_BASE - then_edge->probability;
+ else
+ then_prob = REG_BR_PROB_BASE / 2;
+
+ /* We're speculating from the THEN path, we want to make sure the cost
+ of speculation is within reason. */
+ if (! cheap_bb_rtx_cost_p (then_bb, then_prob,
+ COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge->src),
+ predictable_edge_p (then_edge)))))
return FALSE;
+ if (else_bb == EXIT_BLOCK_PTR)
+ {
+ rtx jump = BB_END (else_edge->src);
+ gcc_assert (JUMP_P (jump));
+ else_target = JUMP_LABEL (jump);
+ }
+
/* Registers set are dead, or are predicable. */
if (! dead_or_predicable (test_bb, then_bb, else_bb,
- single_succ (then_bb), 1))
+ single_succ_edge (then_bb), 1))
return FALSE;
/* Conversion went ok, including moving the insns and fixing up the
redirect_edge_succ (FALLTHRU_EDGE (test_bb), else_bb);
new_bb = 0;
}
+ else if (else_bb == EXIT_BLOCK_PTR)
+ new_bb = force_nonfallthru_and_redirect (FALLTHRU_EDGE (test_bb),
+ else_bb, else_target);
else
new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb),
else_bb);
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest;
edge else_succ;
- rtx note;
+ int then_prob, else_prob;
/* If we are partitioning hot/cold basic blocks, we don't want to
mess up unconditional or indirect jumps that cross between hot
if (then_bb->index < NUM_FIXED_BLOCKS)
return FALSE;
+ if (else_edge->probability)
+ {
+ else_prob = else_edge->probability;
+ then_prob = REG_BR_PROB_BASE - else_prob;
+ }
+ else
+ {
+ else_prob = REG_BR_PROB_BASE / 2;
+ then_prob = REG_BR_PROB_BASE / 2;
+ }
+
/* 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)
+ if (else_prob > then_prob)
;
else if (else_succ->dest->index < NUM_FIXED_BLOCKS
|| dominated_by_p (CDI_POST_DOMINATORS, then_bb,
"\nIF-CASE-2 found, start %d, else %d\n",
test_bb->index, else_bb->index);
- /* ELSE is small. */
- if (! cheap_bb_rtx_cost_p (else_bb, COSTS_N_INSNS (BRANCH_COST)))
+ /* We're speculating from the ELSE path, we want to make sure the cost
+ of speculation is within reason. */
+ if (! cheap_bb_rtx_cost_p (else_bb, else_prob,
+ 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. */
- if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
+ if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ, 0))
return FALSE;
/* Conversion went ok, including moving the insns and fixing up the
return TRUE;
}
-/* A subroutine of dead_or_predicable called through for_each_rtx.
- Return 1 if a memory is found. */
-
-static int
-find_memory (rtx *px, void *data ATTRIBUTE_UNUSED)
-{
- return MEM_P (*px);
-}
-
/* Used by the code above to perform the actual rtl transformations.
Return TRUE if successful.
TEST_BB is the block containing the conditional branch. MERGE_BB
- is the block containing the code to manipulate. NEW_DEST is the
- label TEST_BB should be branching to after the conversion.
+ is the block containing the code to manipulate. DEST_EDGE is an
+ edge representing a jump to the join block; after the conversion,
+ TEST_BB should be branching to its destination.
REVERSEP is true if the sense of the branch should be reversed. */
static int
dead_or_predicable (basic_block test_bb, basic_block merge_bb,
- basic_block other_bb, basic_block new_dest, int reversep)
+ basic_block other_bb, edge dest_edge, int reversep)
{
- rtx head, end, jump, earliest = NULL_RTX, old_dest, new_label = NULL_RTX;
+ basic_block new_dest = dest_edge->dest;
+ rtx head, end, jump, earliest = NULL_RTX, old_dest;
+ bitmap merge_set = NULL;
+ /* Number of pending changes. */
+ int n_validated_changes = 0;
+ rtx new_dest_label = NULL_RTX;
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
+
+ /* 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 ();
+
+ /* Try the NCE path if the CE path did not result in any changes. */
+ if (n_validated_changes == 0)
{
+ rtx cond, insn;
+ regset live;
+ bool success;
+
/* 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;
- unsigned i, fail = 0;
- bitmap_iterator bi;
-
- /* Check for no calls or trapping operations. */
- for (insn = head; ; insn = NEXT_INSN (insn))
- {
- if (CALL_P (insn))
- return FALSE;
- if (INSN_P (insn))
- {
- if (may_trap_p (PATTERN (insn)))
- return FALSE;
-
- /* ??? Even non-trapping memories such as stack frame
- references must be avoided. For stores, we collect
- no lifetime info; for reads, we'd have to assert
- true_dependence false against every store in the
- TEST range. */
- if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
- return FALSE;
- }
- if (insn == end)
- break;
- }
-
- if (! any_condjump_p (jump))
+ if (!any_condjump_p (jump))
return FALSE;
/* Find the extent of the conditional. */
cond = noce_get_condition (jump, &earliest, false);
- if (! cond)
+ if (!cond)
return FALSE;
- /* Collect:
- MERGE_SET = set of registers set in MERGE_BB
- TEST_LIVE = set of registers live at EARLIEST
- TEST_SET = set of registers set between EARLIEST and the
- end of the block. */
+ live = BITMAP_ALLOC (®_obstack);
+ simulate_backwards_to_point (merge_bb, live, end);
+ success = can_move_insns_across (head, end, earliest, jump,
+ merge_bb, live,
+ df_get_live_in (other_bb), NULL);
+ BITMAP_FREE (live);
+ if (!success)
+ return FALSE;
+ /* Collect the set of registers set in MERGE_BB. */
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. */
- /* 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))
+ df_simulate_find_defs (insn, merge_set);
+
+#ifdef HAVE_simple_return
+ /* If shrink-wrapping, disable this optimization when test_bb is
+ the first basic block and merge_bb exits. The idea is to not
+ move code setting up a return register as that may clobber a
+ register used to pass function parameters, which then must be
+ saved in caller-saved regs. A caller-saved reg requires the
+ prologue, killing a shrink-wrap opportunity. */
+ if ((flag_shrink_wrap && HAVE_simple_return && !epilogue_completed)
+ && ENTRY_BLOCK_PTR->next_bb == test_bb
+ && single_succ_p (new_dest)
+ && single_succ (new_dest) == EXIT_BLOCK_PTR
+ && bitmap_intersect_p (df_get_live_in (new_dest), merge_set))
{
- if (INSN_P (insn))
+ regset return_regs;
+ unsigned int i;
+
+ return_regs = BITMAP_ALLOC (®_obstack);
+
+ /* Start off with the intersection of regs used to pass
+ params and regs used to return values. */
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ if (FUNCTION_ARG_REGNO_P (i)
+ && targetm.calls.function_value_regno_p (i))
+ bitmap_set_bit (return_regs, INCOMING_REGNO (i));
+
+ bitmap_and_into (return_regs, df_get_live_out (ENTRY_BLOCK_PTR));
+ bitmap_and_into (return_regs, df_get_live_in (EXIT_BLOCK_PTR));
+ if (!bitmap_empty_p (return_regs))
{
- unsigned int uid = INSN_UID (insn);
- struct df_ref **def_rec;
- for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
+ FOR_BB_INSNS_REVERSE (new_dest, insn)
+ if (NONDEBUG_INSN_P (insn))
+ {
+ df_ref *def_rec;
+ unsigned int uid = INSN_UID (insn);
+
+ /* If this insn sets any reg in return_regs.. */
+ for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ unsigned r = DF_REF_REGNO (def);
+
+ if (bitmap_bit_p (return_regs, r))
+ break;
+ }
+ /* ..then add all reg uses to the set of regs
+ we're interested in. */
+ if (*def_rec)
+ df_simulate_uses (insn, return_regs);
+ }
+ if (bitmap_intersect_p (merge_set, return_regs))
{
- struct df_ref *def = *def_rec;
- bitmap_set_bit (merge_set, DF_REF_REGNO (def));
+ BITMAP_FREE (return_regs);
+ BITMAP_FREE (merge_set);
+ return FALSE;
}
}
+ BITMAP_FREE (return_regs);
}
-
- /* For small register class machines, don't lengthen lifetimes of
- hard registers before reload. */
- if (SMALL_REGISTER_CLASSES && ! reload_completed)
- {
- EXECUTE_IF_SET_IN_BITMAP (merge_set, 0, i, bi)
- {
- if (i < FIRST_PSEUDO_REGISTER
- && ! fixed_regs[i]
- && ! global_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
- after JUMP, and calculates the live set before EARLIEST. */
- bitmap_copy (test_live, df_get_live_in (other_bb));
- df_simulate_artificial_refs_at_end (test_bb, test_live);
- for (insn = jump; ; insn = prev)
- {
- 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;
- }
-
- /* We can perform the transformation if
- MERGE_SET & (TEST_SET | TEST_LIVE)
- and
- 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, df_get_live_in (merge_bb)))
- fail = 1;
-
- BITMAP_FREE (merge_set);
- BITMAP_FREE (test_live);
- BITMAP_FREE (test_set);
-
- if (fail)
- return FALSE;
+#endif
}
no_body:
old_dest = JUMP_LABEL (jump);
if (other_bb != new_dest)
{
- new_label = block_label (new_dest);
+ if (JUMP_P (BB_END (dest_edge->src)))
+ new_dest_label = JUMP_LABEL (BB_END (dest_edge->src));
+ else if (new_dest == EXIT_BLOCK_PTR)
+ new_dest_label = ret_rtx;
+ else
+ new_dest_label = block_label (new_dest);
+
if (reversep
- ? ! invert_jump_1 (jump, new_label)
- : ! redirect_jump_1 (jump, new_label))
+ ? ! invert_jump_1 (jump, new_dest_label)
+ : ! redirect_jump_1 (jump, new_dest_label))
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)
{
- redirect_jump_2 (jump, old_dest, new_label, 0, reversep);
+ redirect_jump_2 (jump, old_dest, new_dest_label, 0, reversep);
redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
if (reversep)
if (end == BB_END (merge_bb))
BB_END (merge_bb) = PREV_INSN (head);
- /* PR 21767: When moving insns above a conditional branch, REG_EQUAL
- notes might become invalid. */
+ /* PR 21767: when moving insns above a conditional branch, the REG_EQUAL
+ notes being moved might become invalid. */
insn = head;
do
{
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)));
+ /* PR46315: when moving insns above a conditional branch, the REG_EQUAL
+ notes referring to the registers being set might become invalid. */
+ if (merge_set)
+ {
+ unsigned i;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (merge_set, 0, i, bi)
+ remove_reg_equal_equiv_notes_for_regno (i);
+
+ BITMAP_FREE (merge_set);
+ }
+
reorder_insns (head, end, PREV_INSN (earliest));
}
cancel:
cancel_changes (0);
+
+ if (merge_set)
+ BITMAP_FREE (merge_set);
+
return FALSE;
}
\f
/* Main entry point for all if-conversion. */
static void
-if_convert (bool recompute_dominance)
+if_convert (void)
{
basic_block bb;
int pass;
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);
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 |
+ 0 /* 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)
{
- if_convert (true);
+ 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_dump_func |
- TODO_ggc_collect, /* todo_flags_finish */
- 'C' /* letter */
+ TODO_df_finish | TODO_verify_rtl_sharing |
+ TODO_ggc_collect /* todo_flags_finish */
+ }
};
static bool
gate_handle_if_after_reload (void)
{
- return (optimize > 0 && flag_if_conversion2);
+ return optimize > 0 && flag_if_conversion2
+ && dbg_cnt (if_after_reload);
}
static unsigned int
rest_of_handle_if_after_reload (void)
{
- 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_dump_func |
- TODO_ggc_collect, /* todo_flags_finish */
- 'E' /* letter */
+ TODO_df_finish | TODO_verify_rtl_sharing |
+ TODO_ggc_collect /* todo_flags_finish */
+ }
};