From: Richard Guenther <rguenther@suse.de>
Date: Fri, 29 Jul 2011 09:54:23 +0000 (+0000)
Subject: re PR middle-end/49893 (-O3 generates wrong code for volatile)
X-Git-Tag: releases/gcc-4.7.0~5037
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=64fb0d3a7878671e4df0b58ab3aa00e4e860e62e;p=thirdparty%2Fgcc.git

re PR middle-end/49893 (-O3 generates wrong code for volatile)

2011-07-29  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/49893
	* tree-predcom.c (suitable_reference_p): Volatile references
	are not suitable.

From-SVN: r176921
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2d12436df0c4..5653050796b3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-07-29  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/49893
+	* tree-predcom.c (suitable_reference_p): Volatile references
+	are not suitable.
+
 2011-07-29  Georg-Johann Lay  <avr@gjlay.de>
 	
 	PR target/49313
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index 94b0512bdafd..ac2314778a80 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -598,6 +598,7 @@ suitable_reference_p (struct data_reference *a, enum ref_step_type *ref_step)
   tree ref = DR_REF (a), step = DR_STEP (a);
 
   if (!step
+      || TREE_THIS_VOLATILE (ref)
       || !is_gimple_reg_type (TREE_TYPE (ref))
       || tree_could_throw_p (ref))
     return false;