/* If-conversion support.
- Copyright (C) 2000 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001 Free Software Foundation, Inc.
- This file is part of GNU CC.
+ This file is part of GCC.
- GNU CC is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
+ GCC is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
- GNU CC is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
+ GCC is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ License for more details.
You should have received a copy of the GNU General Public License
- along with GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with GCC; see the file COPYING. If not, write to the Free
+ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+ 02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "expr.h"
#include "real.h"
#include "output.h"
+#include "toplev.h"
#include "tm_p.h"
#ifndef HAVE_decscc
#define HAVE_decscc 0
#endif
+#ifndef HAVE_trap
+#define HAVE_trap 0
+#endif
+#ifndef HAVE_conditional_trap
+#define HAVE_conditional_trap 0
+#endif
#ifndef MAX_CONDITIONAL_EXECUTE
#define MAX_CONDITIONAL_EXECUTE (BRANCH_COST + 1)
/* # of basic blocks that were removed. */
static int num_removed_blocks;
+/* True if life data ok at present. */
+static bool life_data_ok;
+
/* The post-dominator relation on the original block numbers. */
static sbitmap *post_dominators;
static int find_if_block PARAMS ((basic_block, edge, edge));
static int find_if_case_1 PARAMS ((basic_block, edge, edge));
static int find_if_case_2 PARAMS ((basic_block, edge, edge));
+static int find_cond_trap PARAMS ((basic_block, edge, edge));
static int find_memory PARAMS ((rtx *, void *));
static int dead_or_predicable PARAMS ((basic_block, basic_block,
- basic_block, rtx, int));
+ basic_block, basic_block, int));
+static void noce_emit_move_insn PARAMS ((rtx, rtx));
\f
/* Abuse the basic_block AUX field to store the original block index,
as well as a flag indicating that the block should be rescaned for
reverse the condition. */
if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF
&& XEXP (XEXP (test_if, 2), 0) == JUMP_LABEL (jump))
- cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
- GET_MODE (cond), XEXP (cond, 0),
- XEXP (cond, 1));
+ {
+ enum rtx_code rev = reversed_comparison_code (cond, jump);
+ if (rev == UNKNOWN)
+ return NULL_RTX;
+
+ cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
+ XEXP (cond, 1));
+ }
return cond;
}
rtx then_end; /* last insn + 1 in THEN block */
rtx else_start = NULL_RTX; /* first insn in ELSE block or NULL */
rtx else_end = NULL_RTX; /* last insn + 1 in ELSE block */
- int max; /* max # of insns to convert. */
+ int max; /* max # of insns to convert. */
int then_mod_ok; /* whether conditional mods are ok in THEN */
rtx true_expr; /* test for else block insns */
rtx false_expr; /* test for then block insns */
rtx true_prob_val; /* probability of else block */
rtx false_prob_val; /* probability of then block */
int n_insns;
+ enum rtx_code false_code;
/* Find the conditional jump to the ELSE or JOIN part, and isolate
the test. */
the conditionally executed code. */
true_expr = test_expr;
- false_expr = gen_rtx_fmt_ee (reverse_condition (GET_CODE (true_expr)),
- GET_MODE (true_expr), XEXP (true_expr, 0),
- XEXP (true_expr, 1));
+
+ false_code = reversed_comparison_code (true_expr, test_bb->end);
+ if (false_code != UNKNOWN)
+ false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr),
+ XEXP (true_expr, 0), XEXP (true_expr, 1));
+ else
+ false_expr = NULL_RTX;
#ifdef IFCVT_MODIFY_TESTS
/* If the machine description needs to modify the tests, such as setting a
to conditional execution. */
if (then_end
- && ! cond_exec_process_insns (then_start, then_end,
- false_expr, false_prob_val, then_mod_ok))
+ && (! false_expr
+ || ! cond_exec_process_insns (then_start, then_end, false_expr,
+ false_prob_val, then_mod_ok)))
goto fail;
if (else_bb
if (cond_complex)
cond = XEXP (SET_SRC (pc_set (if_info->jump)), 0);
+ if (reversep)
+ code = reversed_comparison_code (cond, if_info->jump);
+ else
+ code = GET_CODE (cond);
+
if ((if_info->cond_earliest == if_info->jump || cond_complex)
&& (normalize == 0 || STORE_FLAG_VALUE == normalize))
{
rtx tmp;
- code = GET_CODE (cond);
- if (reversep)
- code = reverse_condition (code);
-
tmp = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0),
XEXP (cond, 1));
tmp = gen_rtx_SET (VOIDmode, x, tmp);
if (cond_complex)
return NULL_RTX;
- code = GET_CODE (cond);
- if (reversep)
- code = reverse_condition (code);
-
return emit_store_flag (x, code, XEXP (cond, 0),
XEXP (cond, 1), VOIDmode,
(code == LTU || code == LEU
|| code == GEU || code == GTU), normalize);
}
+/* Emit instruction to move an rtx into STRICT_LOW_PART. */
+static void
+noce_emit_move_insn (x, y)
+ rtx x, y;
+{
+ enum machine_mode outmode, inmode;
+ rtx outer, inner;
+ int bitpos;
+
+ if (GET_CODE (x) != STRICT_LOW_PART)
+ {
+ emit_move_insn (x, y);
+ return;
+ }
+
+ outer = XEXP (x, 0);
+ inner = XEXP (outer, 0);
+ outmode = GET_MODE (outer);
+ inmode = GET_MODE (inner);
+ bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
+ store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos, outmode, y,
+ GET_MODE_BITSIZE (inmode));
+}
+
/* Convert "if (test) x = 1; else x = 0".
Only try 0 and STORE_FLAG_VALUE here. Other combinations will be
else if (if_info->b == const0_rtx
&& GET_CODE (if_info->a) == CONST_INT
&& INTVAL (if_info->a) == STORE_FLAG_VALUE
- && can_reverse_comparison_p (if_info->cond, if_info->jump))
+ && (reversed_comparison_code (if_info->cond, if_info->jump)
+ != UNKNOWN))
reversep = 1;
else
return FALSE;
if (target)
{
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
int reversep;
HOST_WIDE_INT itrue, ifalse, diff, tmp;
int normalize, can_reverse;
+ enum machine_mode mode;
if (! no_new_pseudos
&& GET_CODE (if_info->a) == CONST_INT
&& GET_CODE (if_info->b) == CONST_INT)
{
+ mode = GET_MODE (if_info->x);
ifalse = INTVAL (if_info->a);
itrue = INTVAL (if_info->b);
- diff = itrue - ifalse;
- can_reverse = can_reverse_comparison_p (if_info->cond, if_info->jump);
+ /* Make sure we can represent the difference between the two values. */
+ if ((itrue - ifalse > 0)
+ != ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue))
+ return FALSE;
+
+ diff = trunc_int_for_mode (itrue - ifalse, mode);
+
+ can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)
+ != UNKNOWN);
reversep = 0;
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
if (reversep)
{
tmp = itrue; itrue = ifalse; ifalse = tmp;
- diff = -diff;
+ diff = trunc_int_for_mode (-diff, mode);
}
start_sequence ();
=> x = 3 + (test == 0); */
if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
{
- target = expand_binop (GET_MODE (if_info->x),
- (diff == STORE_FLAG_VALUE
- ? add_optab : sub_optab),
- GEN_INT (ifalse), target, if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode,
+ (diff == STORE_FLAG_VALUE
+ ? PLUS : MINUS),
+ GEN_INT (ifalse), target, if_info->x, 0,
+ OPTAB_WIDEN);
}
/* if (test) x = 8; else x = 0;
=> x = (test != 0) << 3; */
else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0)
{
- target = expand_binop (GET_MODE (if_info->x), ashl_optab,
- target, GEN_INT (tmp), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, ASHIFT,
+ target, GEN_INT (tmp), if_info->x, 0,
+ OPTAB_WIDEN);
}
/* if (test) x = -1; else x = b;
=> x = -(test != 0) | b; */
else if (itrue == -1)
{
- target = expand_binop (GET_MODE (if_info->x), ior_optab,
- target, GEN_INT (ifalse), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, IOR,
+ target, GEN_INT (ifalse), if_info->x, 0,
+ OPTAB_WIDEN);
}
/* if (test) x = a; else x = b;
=> x = (-(test != 0) & (b - a)) + a; */
else
{
- target = expand_binop (GET_MODE (if_info->x), and_optab,
- target, GEN_INT (diff), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, AND,
+ target, GEN_INT (diff), if_info->x, 0,
+ OPTAB_WIDEN);
if (target)
- target = expand_binop (GET_MODE (if_info->x), add_optab,
- target, GEN_INT (ifalse), if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (mode, PLUS,
+ target, GEN_INT (ifalse),
+ if_info->x, 0, OPTAB_WIDEN);
}
if (! target)
}
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
&& (XEXP (if_info->a, 1) == const1_rtx
|| XEXP (if_info->a, 1) == constm1_rtx)
&& rtx_equal_p (XEXP (if_info->a, 0), if_info->x)
- && can_reverse_comparison_p (if_info->cond, if_info->jump))
+ && (reversed_comparison_code (if_info->cond, if_info->jump)
+ != UNKNOWN))
{
if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
subtract = 0, normalize = 0;
1, normalize);
if (target)
- target = expand_binop (GET_MODE (if_info->x),
- subtract ? sub_optab : add_optab,
- if_info->x, target, if_info->x, 0, OPTAB_WIDEN);
+ target = expand_simple_binop (GET_MODE (if_info->x),
+ subtract ? MINUS : PLUS,
+ if_info->x, target, if_info->x,
+ 0, OPTAB_WIDEN);
if (target)
{
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
|| STORE_FLAG_VALUE == -1)
&& ((if_info->a == const0_rtx
&& rtx_equal_p (if_info->b, if_info->x))
- || ((reversep = can_reverse_comparison_p (if_info->cond,
- if_info->jump))
+ || ((reversep = (reversed_comparison_code (if_info->cond,
+ if_info->jump)
+ != UNKNOWN))
&& if_info->b == const0_rtx
&& rtx_equal_p (if_info->a, if_info->x))))
{
gen_reg_rtx (GET_MODE (if_info->x)),
reversep, -1);
if (target)
- target = expand_binop (GET_MODE (if_info->x), and_optab,
- if_info->x, target, if_info->x, 0,
- OPTAB_WIDEN);
+ target = expand_simple_binop (GET_MODE (if_info->x), AND,
+ if_info->x, target, if_info->x, 0,
+ OPTAB_WIDEN);
if (target)
{
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
if (target)
{
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
insn_b = if_info->insn_b;
/* Possibly rearrange operands to make things come out more natural. */
- if (can_reverse_comparison_p (if_info->cond, if_info->jump))
+ if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
{
int reversep = 0;
if (rtx_equal_p (b, x))
if (reversep)
{
- code = reverse_condition (code);
+ code = reversed_comparison_code (if_info->cond, if_info->jump);
tmp = a, a = b, b = tmp;
tmp = insn_a, insn_a = insn_b, insn_b = tmp;
}
if (MEM_SCALAR_P (if_info->a) && MEM_SCALAR_P (if_info->b))
MEM_SCALAR_P (tmp) = 1;
if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
- MEM_ALIAS_SET (tmp) = MEM_ALIAS_SET (if_info->a);
+ set_mem_alias_set (tmp, MEM_ALIAS_SET (if_info->a));
+ set_mem_align (tmp,
+ MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));
- emit_move_insn (if_info->x, tmp);
+ noce_emit_move_insn (if_info->x, tmp);
}
else if (target != x)
- emit_move_insn (x, target);
+ noce_emit_move_insn (x, target);
tmp = get_insns ();
end_sequence ();
= GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
&& XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (if_info->jump);
+ /* If we're looking for a constant, try to make the conditional
+ have that constant in it. There are two reasons why it may
+ not have the constant we want:
+
+ 1. GCC may have needed to put the constant in a register, because
+ the target can't compare directly against that constant. For
+ this case, we look for a SET immediately before the comparison
+ that puts a constant in that register.
+
+ 2. GCC may have canonicalized the conditional, for example
+ replacing "if x < 4" with "if x <= 3". We can undo that (or
+ make equivalent types of changes) to get the constants we need
+ if they're off by one in the right direction. */
+
+ if (GET_CODE (target) == CONST_INT)
+ {
+ enum rtx_code code = GET_CODE (if_info->cond);
+ rtx op_a = XEXP (if_info->cond, 0);
+ rtx op_b = XEXP (if_info->cond, 1);
+ rtx prev_insn;
+
+ /* First, look to see if we put a constant in a register. */
+ prev_insn = PREV_INSN (if_info->cond_earliest);
+ if (prev_insn
+ && INSN_P (prev_insn)
+ && GET_CODE (PATTERN (prev_insn)) == SET)
+ {
+ rtx src = find_reg_equal_equiv_note (prev_insn);
+ if (!src)
+ src = SET_SRC (PATTERN (prev_insn));
+ if (GET_CODE (src) == CONST_INT)
+ {
+ if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
+ op_a = src;
+ else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
+ op_b = src;
+
+ if (GET_CODE (op_a) == CONST_INT)
+ {
+ rtx tmp = op_a;
+ op_a = op_b;
+ op_b = tmp;
+ code = swap_condition (code);
+ }
+ }
+ }
+
+ /* Now, look to see if we can get the right constant by
+ adjusting the conditional. */
+ if (GET_CODE (op_b) == CONST_INT)
+ {
+ HOST_WIDE_INT desired_val = INTVAL (target);
+ HOST_WIDE_INT actual_val = INTVAL (op_b);
+
+ switch (code)
+ {
+ case LT:
+ if (actual_val == desired_val + 1)
+ {
+ code = LE;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ case LE:
+ if (actual_val == desired_val - 1)
+ {
+ code = LT;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ case GT:
+ if (actual_val == desired_val - 1)
+ {
+ code = GE;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ case GE:
+ if (actual_val == desired_val + 1)
+ {
+ code = GT;
+ op_b = GEN_INT (desired_val);
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ /* If we made any changes, generate a new conditional that is
+ equivalent to what we started with, but has the right
+ constants in it. */
+ if (code != GET_CODE (if_info->cond)
+ || op_a != XEXP (if_info->cond, 0)
+ || op_b != XEXP (if_info->cond, 1))
+ {
+ cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
+ *earliest = if_info->cond_earliest;
+ return cond;
+ }
+ }
+
cond = canonicalize_condition (if_info->jump, cond, reverse,
earliest, target);
if (! cond || ! reg_mentioned_p (target, cond))
struct noce_if_info *if_info;
{
rtx cond, earliest, target, seq;
- enum rtx_code code;
+ enum rtx_code code, op;
int unsignedp;
- optab op;
/* ??? Can't guarantee that expand_binop won't create pseudos. */
if (no_new_pseudos)
to get the target to tell us... */
if (FLOAT_MODE_P (GET_MODE (if_info->x))
&& TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
- && ! flag_fast_math)
+ && ! flag_unsafe_math_optimizations)
return FALSE;
cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
case LE:
case UNLT:
case UNLE:
- op = smax_optab;
+ op = SMAX;
unsignedp = 0;
break;
case GT:
case GE:
case UNGT:
case UNGE:
- op = smin_optab;
+ op = SMIN;
unsignedp = 0;
break;
case LTU:
case LEU:
- op = umax_optab;
+ op = UMAX;
unsignedp = 1;
break;
case GTU:
case GEU:
- op = umin_optab;
+ op = UMIN;
unsignedp = 1;
break;
default:
start_sequence ();
- target = expand_binop (GET_MODE (if_info->x), op, if_info->a, if_info->b,
- if_info->x, unsignedp, OPTAB_WIDEN);
+ target = expand_simple_binop (GET_MODE (if_info->x), op,
+ if_info->a, if_info->b,
+ if_info->x, unsignedp, OPTAB_WIDEN);
if (! target)
{
end_sequence ();
return FALSE;
}
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
start_sequence ();
- target = expand_unop (GET_MODE (if_info->x), abs_optab, b, if_info->x, 0);
+ target = expand_simple_unop (GET_MODE (if_info->x), ABS, b, if_info->x, 0);
/* ??? It's a quandry whether cmove would be better here, especially
for integers. Perhaps combine will clean things up. */
if (target && negate)
- target = expand_unop (GET_MODE (target), neg_optab, target, if_info->x, 0);
+ target = expand_simple_unop (GET_MODE (target), NEG, target, if_info->x, 0);
if (! target)
{
}
if (target != if_info->x)
- emit_move_insn (if_info->x, target);
+ noce_emit_move_insn (if_info->x, target);
seq = get_insns ();
end_sequence ();
if (side_effects_p (op))
return FALSE;
- /* ??? Unfortuantely may_trap_p can't look at flag_fast_math, due to
+ /* ??? Unfortuantely may_trap_p can't look at flag_trapping_math, due to
being linked into the genfoo programs. This is probably a mistake.
With finite operands, most fp operations don't trap. */
- if (flag_fast_math && FLOAT_MODE_P (GET_MODE (op)))
+ if (!flag_trapping_math && FLOAT_MODE_P (GET_MODE (op)))
switch (GET_CODE (op))
{
case DIV:
default:
switch (GET_RTX_CLASS (GET_CODE (op)))
{
- case 'c':
case '1':
+ return ! may_trap_p (XEXP (op, 0));
+ case 'c':
case '2':
return ! may_trap_p (XEXP (op, 0)) && ! may_trap_p (XEXP (op, 1));
}
{
if (no_new_pseudos)
return FALSE;
- x = gen_reg_rtx (GET_MODE (x));
+ x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
+ ? XEXP (x, 0) : x));
}
/* Don't operate on sources that may trap or are volatile. */
that case don't do anything and let the code below delete INSN_A. */
if (insn_b && else_bb)
{
+ rtx note;
+
if (else_bb && insn_b == else_bb->end)
else_bb->end = PREV_INSN (insn_b);
reorder_insns (insn_b, insn_b, PREV_INSN (if_info.cond_earliest));
+
+ /* If there was a REG_EQUAL note, delete it since it may have been
+ true due to this insn being after a jump. */
+ if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
+ remove_note (insn_b, note);
+
insn_b = NULL_RTX;
}
/* If we have "x = b; if (...) x = a;", and x has side-effects, then
success:
/* The original sets may now be killed. */
- if (insn_a == then_bb->end)
- then_bb->end = PREV_INSN (insn_a);
- flow_delete_insn (insn_a);
+ delete_insn (insn_a);
/* Several special cases here: First, we may have reused insn_b above,
in which case insn_b is now NULL. Second, we want to delete insn_b
the TEST block, it may in fact be loading data needed for the comparison.
We'll let life_analysis remove the insn if it's really dead. */
if (insn_b && else_bb)
- {
- if (insn_b == else_bb->end)
- else_bb->end = PREV_INSN (insn_b);
- flow_delete_insn (insn_b);
- }
+ delete_insn (insn_b);
/* The new insns will have been inserted before cond_earliest. We should
be able to remove the jump with impunity, but the condition itself may
have been modified by gcse to be shared across basic blocks. */
- test_bb->end = PREV_INSN (jump);
- flow_delete_insn (jump);
+ delete_insn (jump);
/* If we used a temporary, fix it up now. */
if (orig_x != x)
{
start_sequence ();
- emit_move_insn (orig_x, x);
+ noce_emit_move_insn (orig_x, x);
insn_b = gen_sequence ();
end_sequence ();
- test_bb->end = emit_insn_after (insn_b, test_bb->end);
+ emit_insn_after (insn_b, test_bb->end);
}
/* Merge the blocks! */
/* First merge TEST block into THEN block. This is a no-brainer since
the THEN block did not have a code label to begin with. */
- if (combo_bb->global_live_at_end)
+ if (life_data_ok)
COPY_REG_SET (combo_bb->global_live_at_end, then_bb->global_live_at_end);
merge_blocks_nomove (combo_bb, then_bb);
num_removed_blocks++;
if (combo_bb->succ == NULL_EDGE)
abort ();
- /* There should sill be a branch at the end of the THEN or ELSE
+ /* There should still be a branch at the end of the THEN or ELSE
blocks taking us to our final destination. */
- if (! simplejump_p (combo_bb->end)
- && ! returnjump_p (combo_bb->end))
+ if (GET_CODE (combo_bb->end) != JUMP_INSN)
abort ();
}
is more than one remaining edge, it must come from elsewhere. There
may be zero incoming edges if the THEN block didn't actually join
back up (as with a call to abort). */
- else if (join_bb->pred == NULL || join_bb->pred->pred_next == NULL)
+ else if ((join_bb->pred == NULL
+ || join_bb->pred->pred_next == NULL)
+ && join_bb != EXIT_BLOCK_PTR)
{
/* We can merge the JOIN. */
- if (combo_bb->global_live_at_end)
+ if (life_data_ok)
COPY_REG_SET (combo_bb->global_live_at_end,
join_bb->global_live_at_end);
merge_blocks_nomove (combo_bb, join_bb);
abort ();
/* Remove the jump and cruft from the end of the COMBO block. */
- tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
+ if (join_bb != EXIT_BLOCK_PTR)
+ tidy_fallthru_edge (combo_bb->succ, combo_bb, join_bb);
}
/* Make sure we update life info properly. */
if (find_if_block (test_bb, then_edge, else_edge))
goto success;
+ if (HAVE_trap && HAVE_conditional_trap
+ && find_cond_trap (test_bb, then_edge, else_edge))
+ goto success;
if (post_dominators
&& (! HAVE_conditional_execution || reload_completed))
{
/* Make sure IF, THEN, and ELSE, blocks are adjacent. Actually, we
get the first condition for free, since we've already asserted that
there's a fallthru edge from IF to THEN. */
- /* ??? As an enhancement, move the ELSE block. Have to deal with EH and
+ /* ??? As an enhancement, move the ELSE block. Have to deal with
BLOCK notes, if by no other means than aborting the merge if they
exist. Sticky enough I don't want to think about it now. */
next_index = then_bb->index;
if (else_bb && ++next_index != else_bb->index)
return FALSE;
- if (++next_index != join_bb->index)
+ if (++next_index != join_bb->index && join_bb->index != EXIT_BLOCK)
{
if (else_bb)
join_bb = NULL;
return process_if_block (test_bb, then_bb, else_bb, join_bb);
}
+/* Convert a branch over a trap, or a branch to a trap,
+ into a conditional trap. */
+
+static int
+find_cond_trap (test_bb, then_edge, else_edge)
+ basic_block test_bb;
+ edge then_edge, else_edge;
+{
+ basic_block then_bb, else_bb, join_bb, trap_bb;
+ rtx trap, jump, cond, cond_earliest, seq;
+ enum rtx_code code;
+
+ then_bb = then_edge->dest;
+ else_bb = else_edge->dest;
+ join_bb = NULL;
+
+ /* Locate the block with the trap instruction. */
+ /* ??? While we look for no successors, we really ought to allow
+ EH successors. Need to fix merge_if_block for that to work. */
+ /* ??? We can't currently handle merging the blocks if they are not
+ already adjacent. Prevent losage in merge_if_block by detecting
+ this now. */
+ if (then_bb->succ == NULL)
+ {
+ trap_bb = then_bb;
+ if (else_bb->index != then_bb->index + 1)
+ return FALSE;
+ join_bb = else_bb;
+ else_bb = NULL;
+ }
+ else if (else_bb->succ == NULL)
+ {
+ trap_bb = else_bb;
+ if (else_bb->index != then_bb->index + 1)
+ else_bb = NULL;
+ else if (then_bb->succ
+ && ! then_bb->succ->succ_next
+ && ! (then_bb->succ->flags & EDGE_COMPLEX)
+ && then_bb->succ->dest->index == else_bb->index + 1)
+ join_bb = then_bb->succ->dest;
+ }
+ else
+ return FALSE;
+
+ /* Don't confuse a conditional return with something we want to
+ optimize here. */
+ if (trap_bb == EXIT_BLOCK_PTR)
+ return FALSE;
+
+ /* The only instruction in the THEN block must be the trap. */
+ trap = first_active_insn (trap_bb);
+ if (! (trap == trap_bb->end
+ && GET_CODE (PATTERN (trap)) == TRAP_IF
+ && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
+ return FALSE;
+
+ if (rtl_dump_file)
+ {
+ if (trap_bb == then_bb)
+ fprintf (rtl_dump_file,
+ "\nTRAP-IF block found, start %d, trap %d",
+ test_bb->index, then_bb->index);
+ else
+ fprintf (rtl_dump_file,
+ "\nTRAP-IF block found, start %d, then %d, trap %d",
+ test_bb->index, then_bb->index, trap_bb->index);
+ if (join_bb)
+ fprintf (rtl_dump_file, ", join %d\n", join_bb->index);
+ else
+ fputc ('\n', rtl_dump_file);
+ }
+
+ /* If this is not a standard conditional jump, we can't parse it. */
+ jump = test_bb->end;
+ cond = noce_get_condition (jump, &cond_earliest);
+ if (! cond)
+ return FALSE;
+
+ /* If the conditional jump is more than just a conditional jump,
+ then we can not do if-conversion on this block. */
+ if (! onlyjump_p (jump))
+ return FALSE;
+
+ /* We must be comparing objects whose modes imply the size. */
+ if (GET_MODE (XEXP (cond, 0)) == BLKmode)
+ return FALSE;
+
+ /* Reverse the comparison code, if necessary. */
+ code = GET_CODE (cond);
+ if (then_bb == trap_bb)
+ {
+ code = reversed_comparison_code (cond, jump);
+ if (code == UNKNOWN)
+ return FALSE;
+ }
+
+ /* Attempt to generate the conditional trap. */
+ seq = gen_cond_trap (code, XEXP (cond, 0), XEXP (cond, 1),
+ TRAP_CODE (PATTERN (trap)));
+ if (seq == NULL)
+ return FALSE;
+
+ /* Emit the new insns before cond_earliest; delete the old jump
+ and trap insns. */
+
+ emit_insn_before (seq, cond_earliest);
+
+ delete_insn (jump);
+
+ delete_insn (trap);
+
+ /* Merge the blocks! */
+ if (trap_bb != then_bb && ! else_bb)
+ {
+ flow_delete_block (trap_bb);
+ num_removed_blocks++;
+ }
+ merge_if_block (test_bb, then_bb, else_bb, join_bb);
+
+ return TRUE;
+}
+
/* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
transformable, but not necessarily the other. There need be no
JOIN block.
edge then_edge, else_edge;
{
basic_block then_bb = then_edge->dest;
- basic_block else_bb = else_edge->dest;
+ basic_block else_bb = else_edge->dest, new_bb;
edge then_succ = then_bb->succ;
- rtx new_lab;
/* THEN has one successor. */
if (!then_succ || then_succ->succ_next != NULL)
if (then_bb->pred->pred_next != NULL)
return FALSE;
- /* ELSE follows THEN. (??? could be moved) */
- if (else_bb->index != then_bb->index + 1)
+ /* THEN must do something. */
+ if (forwarder_block_p (then_bb))
return FALSE;
num_possible_if_blocks++;
if (count_bb_insns (then_bb) > BRANCH_COST)
return FALSE;
- /* Find the label for THEN's destination. */
- if (then_succ->dest == EXIT_BLOCK_PTR)
- new_lab = NULL_RTX;
- else
- {
- new_lab = JUMP_LABEL (then_bb->end);
- if (! new_lab)
- abort ();
- }
-
/* Registers set are dead, or are predicable. */
- if (! dead_or_predicable (test_bb, then_bb, else_bb, new_lab, 1))
+ if (! dead_or_predicable (test_bb, then_bb, else_bb,
+ then_bb->succ->dest, 1))
return FALSE;
/* Conversion went ok, including moving the insns and fixing up the
else_bb->global_live_at_start,
then_bb->global_live_at_end, BITMAP_IOR);
- make_edge (NULL, test_bb, then_succ->dest, 0);
+ new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb), else_bb);
+ /* Make rest of code believe that the newly created block is the THEN_BB
+ block we are going to remove. */
+ if (new_bb)
+ {
+ new_bb->aux = then_bb->aux;
+ SET_UPDATE_LIFE (then_bb);
+ }
flow_delete_block (then_bb);
- tidy_fallthru_edge (else_edge, test_bb, else_bb);
+ /* We've possibly created jump to next insn, cleanup_cfg will solve that
+ later. */
num_removed_blocks++;
num_updated_if_blocks++;
basic_block then_bb = then_edge->dest;
basic_block else_bb = else_edge->dest;
edge else_succ = else_bb->succ;
- rtx new_lab, note;
+ rtx note;
/* ELSE has one successor. */
if (!else_succ || else_succ->succ_next != NULL)
if (count_bb_insns (then_bb) > BRANCH_COST)
return FALSE;
- /* Find the label for ELSE's destination. */
- if (else_succ->dest == EXIT_BLOCK_PTR)
- new_lab = NULL_RTX;
- else
- {
- if (else_succ->flags & EDGE_FALLTHRU)
- {
- new_lab = else_succ->dest->head;
- if (GET_CODE (new_lab) != CODE_LABEL)
- abort ();
- }
- else
- {
- new_lab = JUMP_LABEL (else_bb->end);
- if (! new_lab)
- abort ();
- }
- }
-
/* Registers set are dead, or are predicable. */
- if (! dead_or_predicable (test_bb, else_bb, then_bb, new_lab, 0))
+ if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ->dest, 0))
return FALSE;
/* Conversion went ok, including moving the insns and fixing up the
then_bb->global_live_at_start,
else_bb->global_live_at_end, BITMAP_IOR);
- remove_edge (else_edge);
- make_edge (NULL, test_bb, else_succ->dest, 0);
flow_delete_block (else_bb);
num_removed_blocks++;
static int
dead_or_predicable (test_bb, merge_bb, other_bb, new_dest, reversep)
basic_block test_bb, merge_bb, other_bb;
- rtx new_dest;
+ basic_block new_dest;
int reversep;
{
- rtx head, end, jump, earliest, old_dest;
-
- /* No code movement can occur if we'd be scrogging EH regions.
- Within MERGE_BB, ensure that we've not got stray EH_BEG or EH_END
- notes within the block. Between the blocks, checking that the end
- region numbers match ensures that we won't disrupt the nesting
- between regions. */
- if (merge_bb->eh_beg != merge_bb->eh_end
- || merge_bb->eh_end != test_bb->eh_end)
- return FALSE;
+ rtx head, end, jump, earliest, old_dest, new_label;
jump = test_bb->end;
rtx cond, prob_val;
cond = cond_exec_get_condition (jump);
+ if (! cond)
+ return FALSE;
prob_val = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
if (prob_val)
if (reversep)
{
- cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
- GET_MODE (cond), XEXP (cond, 0),
+ enum rtx_code rev = reversed_comparison_code (cond, jump);
+ if (rev == UNKNOWN)
+ return FALSE;
+ cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
XEXP (cond, 1));
if (prob_val)
prob_val = GEN_INT (REG_BR_PROB_BASE - INTVAL (prob_val));
/* ??? Even non-trapping memories such as stack frame
references must be avoided. For stores, we collect
no lifetime info; for reads, we'd have to assert
- true_dependance false against every store in the
+ true_dependence false against every store in the
TEST range. */
if (for_each_rtx (&PATTERN (insn), find_memory, NULL))
return FALSE;
change group management. */
old_dest = JUMP_LABEL (jump);
+ new_label = block_label (new_dest);
if (reversep
- ? ! invert_jump_1 (jump, new_dest)
- : ! redirect_jump_1 (jump, new_dest))
+ ? ! invert_jump_1 (jump, new_label)
+ : ! redirect_jump_1 (jump, new_label))
goto cancel;
if (! apply_change_group ())
if (old_dest)
LABEL_NUSES (old_dest) -= 1;
- if (new_dest)
- LABEL_NUSES (new_dest) += 1;
- JUMP_LABEL (jump) = new_dest;
+ if (new_label)
+ LABEL_NUSES (new_label) += 1;
+ JUMP_LABEL (jump) = new_label;
+
+ if (reversep)
+ invert_br_probabilities (jump);
+ redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
if (reversep)
{
- rtx note = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
- if (note)
- XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0)));
+ gcov_type count, probability;
+ count = BRANCH_EDGE (test_bb)->count;
+ BRANCH_EDGE (test_bb)->count = FALLTHRU_EDGE (test_bb)->count;
+ FALLTHRU_EDGE (test_bb)->count = count;
+ probability = BRANCH_EDGE (test_bb)->probability;
+ BRANCH_EDGE (test_bb)->probability = FALLTHRU_EDGE (test_bb)->probability;
+ FALLTHRU_EDGE (test_bb)->probability = probability;
+ update_br_prob_note (test_bb);
}
/* Move the insns out of MERGE_BB to before the branch. */
if (end == merge_bb->end)
merge_bb->end = PREV_INSN (head);
- head = squeeze_notes (head, end);
- if (GET_CODE (end) == NOTE
- && (NOTE_LINE_NUMBER (end) == NOTE_INSN_BLOCK_END
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_BLOCK_BEG
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_BEG
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_END
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_CONT
- || NOTE_LINE_NUMBER (end) == NOTE_INSN_LOOP_VTOP))
- {
- if (head == end)
- return TRUE;
- end = PREV_INSN (end);
- }
+ if (squeeze_notes (&head, &end))
+ return TRUE;
reorder_insns (head, end, PREV_INSN (earliest));
}
/* Main entry point for all if-conversion. */
void
-if_convert (life_data_ok)
- int life_data_ok;
+if_convert (x_life_data_ok)
+ int x_life_data_ok;
{
int block_num;
num_possible_if_blocks = 0;
num_updated_if_blocks = 0;
num_removed_blocks = 0;
+ life_data_ok = (x_life_data_ok != 0);
/* Free up basic_block_for_insn so that we don't have to keep it
up to date, either here or in merge_blocks_nomove. */
if (rtl_dump_file)
fflush (rtl_dump_file);
- /* Rebuild basic_block_for_insn for update_life_info and for gcse. */
- compute_bb_for_insn (get_max_uid ());
-
/* Rebuild life info for basic blocks that require it. */
if (num_removed_blocks && life_data_ok)
{
sbitmap_free (update_life_blocks);
}
+ clear_aux_for_blocks ();
/* Write the final stats. */
if (rtl_dump_file && num_possible_if_blocks > 0)
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