From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 2 Jul 2010 09:14:03 +0000 (+0000)
Subject: 2010-07-02  Richard Guenther  <rguenther@suse.de>
X-Git-Url: http://git.sourceforge.jp/view?a=commitdiff_plain;h=dbeb5fe04388dccd8ace37626bb29c03cdf11a90;p=pf3gnuchains%2Fgcc-fork.git

2010-07-02  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/44748
	* tree-ssa-ccp.c (fold_const_aggregate_ref): Properly handle
	the embedded conversion in MEM_REFs.

	* gcc.dg/tree-ssa/ssa-ccp-29.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@161689 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 40522695b58..365a719ed81 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2010-07-02  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/44748
+	* tree-ssa-ccp.c (fold_const_aggregate_ref): Properly handle
+	the embedded conversion in MEM_REFs.
+
 2010-07-01  López-Ibáñez  <manu@gcc.gnu.org>
 
 	* reload.c: Include toplev.h.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8d84acde180..d9c0a99a7bd 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-07-02  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/44748
+	* gcc.dg/tree-ssa/ssa-ccp-29.c: New testcase.
+
 2010-07-02  Iain Sandoe  <iains@gcc.gnu.org>
 
 	* objc-obj-c++-shared/next-abi.h: Remove dependency on system
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-29.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-29.c
new file mode 100644
index 00000000000..44d2945a311
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-29.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-ccp2" } */
+
+static double num;
+int foo (void)
+{
+  return *(unsigned *)&num;
+}
+
+/* { dg-final { scan-tree-dump "return 0;" "ccp2" } } */
+/* { dg-final { cleanup-tree-dump "ccp2" } } */
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 912c5059363..1e2309acb16 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -1317,7 +1317,14 @@ fold_const_aggregate_ref (tree t)
 	  if (DECL_P (base)
 	      && !AGGREGATE_TYPE_P (TREE_TYPE (base))
 	      && integer_zerop (TREE_OPERAND (t, 1)))
-	    return get_symbol_constant_value (base);
+	    {
+	      tree res = get_symbol_constant_value (base);
+	      if (res
+		  && !useless_type_conversion_p
+		        (TREE_TYPE (t), TREE_TYPE (res)))
+		res = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (t), res);
+	      return res;
+	    }
 
 	  if (!TREE_READONLY (base)
 	      || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE