From 2e33cac51d19b0ae422cd030cc9a0184b1bc0748 Mon Sep 17 00:00:00 2001
From: rakdver <rakdver@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 16 Feb 2006 15:59:00 +0000
Subject: [PATCH] * loop-invariant.c (invariant_for_use,
check_dependencies): Fail for read-write uses.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@111141 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 5 +++++
gcc/loop-invariant.c | 9 ++++++++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d01a0490d8d5..953abf6cadd5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2006-02-16 Zdenek Dvorak <dvorakz@suse.cz>
+
+ * loop-invariant.c (invariant_for_use, check_dependencies): Fail for
+ read-write uses.
+
2006-02-16 Zdenek Dvorak <dvorakz@suse.cz>
PR rtl-optimization/26296
diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c
index 03a0c34e6cba..04531a0e05fc 100644
--- a/gcc/loop-invariant.c
+++ b/gcc/loop-invariant.c
@@ -233,6 +233,9 @@ invariant_for_use (struct df_ref *use)
struct df_ref *def;
basic_block bb = BLOCK_FOR_INSN (use->insn), def_bb;
+ if (use->flags & DF_REF_READ_WRITE)
+ return NULL;
+
defs = DF_REF_CHAIN (use);
if (!defs || defs->next)
return NULL;
@@ -682,7 +685,8 @@ record_use (struct def *def, rtx *use, rtx insn)
}
/* Finds the invariants INSN depends on and store them to the DEPENDS_ON
- bitmap. */
+ bitmap. Returns true if all dependencies of INSN are known to be
+ loop invariants, false otherwise. */
static bool
check_dependencies (rtx insn, bitmap depends_on)
@@ -695,6 +699,9 @@ check_dependencies (rtx insn, bitmap depends_on)
for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref)
{
+ if (use->flags & DF_REF_READ_WRITE)
+ return false;
+
defs = DF_REF_CHAIN (use);
if (!defs)
continue;
--
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