From b355f2229a07beb1b1b08d1c7e6b7dbac55c8df9 Mon Sep 17 00:00:00 2001
From: Uros Bizjak <uros@kss-loka.si>
Date: Fri, 17 Sep 2004 07:32:36 +0200
Subject: [PATCH] re PR rtl-optimization/15187 (Inefficient if optimization
with -O2 -ffast-math)
PR rtl-optimization/15187
* ifcvt.c (noce_try_cmove_arith): Exit early if total
insn_rtx_cost of both branches > BRANCH_COST
From-SVN: r87631
---
gcc/ChangeLog | 6 ++++++
gcc/ifcvt.c | 20 ++++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bc9fb613629c..9b79868280a7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2004-09-17 Uros Bizjak <uros@kss-loka.si>
+
+ PR rtl-optimization/15187
+ * ifcvt.c (noce_try_cmove_arith): Exit early if total
+ insn_rtx_cost of both branches > BRANCH_COST
+
2004-09-16 Diego Novillo <dnovillo@redhat.com>
PR tree-optimization/17528
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 0767eb25008a..5963158db42f 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1214,6 +1214,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
rtx insn_a, insn_b;
rtx tmp, target;
int is_mem = 0;
+ int insn_cost;
enum rtx_code code;
/* A conditional move from two memory sources is equivalent to a
@@ -1247,6 +1248,25 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
insn_a = if_info->insn_a;
insn_b = if_info->insn_b;
+ /* Total insn_rtx_cost should be smaller than branch cost. Exit
+ 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))
+ return FALSE;
+ }
+ else
+ {
+ insn_cost = 0;
+ }
+
+ if (insn_b) {
+ insn_cost += insn_rtx_cost (PATTERN (insn_b));
+ if (insn_cost == 0 || insn_cost > COSTS_N_INSNS (BRANCH_COST))
+ return FALSE;
+ }
+
/* Possibly rearrange operands to make things come out more natural. */
if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
{
--
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