re PR tree-optimization/50472 (Volatile qualification in data is not enough to avoid...

2011-09-26  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/50472
	* gimple-fold.c (fold_const_aggregate_ref_1): Do not fold
	volatile references.

	* gcc.dg/torture/pr50472.c: New testcase.

From-SVN: r179196

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7b1f54d..899ffe0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,4 +1,11 @@
+2011-09-26  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/50472
+       * gimple-fold.c (fold_const_aggregate_ref_1): Do not fold
+       volatile references.
+
 2011-09-26  Bingfeng Mei <bmei@broadcom.com>
+
        * doc/tm.texi: Correct documentation for TARGET_ADDR_SPACE_SUBSET_P.
        * target.def: (addr_space_subset_p): Likewise.
 

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index b481c4a..d754ea9 100644 (file)
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -2919,6 +2919,9 @@ fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree))
   HOST_WIDE_INT offset, size, max_size;
   tree tem;
 
+  if (TREE_THIS_VOLATILE (t))
+    return NULL_TREE;
+
   if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
     return get_symbol_constant_value (t);
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 35dea73..6caed7a 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-09-26  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/50472
+       * gcc.dg/torture/pr50472.c: New testcase.
+
 2011-09-26  Eric Botcazou  <ebotcazou@adacore.com>
 
        * gnat.dg/opt22.adb: New test.

diff --git a/gcc/testsuite/gcc.dg/torture/pr50472.c b/gcc/testsuite/gcc.dg/torture/pr50472.c
new file mode 100644 (file)
index 0000000..280f2c4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr50472.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-fdump-tree-optimized" } */
+
+static const unsigned int foo = 1;
+unsigned int test( void )
+{
+  const volatile unsigned int *bar = &foo;
+  return ( *bar );
+}
+
+/* { dg-final { scan-tree-dump-not "return 1" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */