2013-08-14  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/58145
	* tree-sra.c (build_ref_for_offset): If base is TREE_THIS_VOLATILE,
	propagate it to exp_type and MEM_REF.

	* gcc.dg/pr58145-1.c: New test.
	* gcc.dg/pr58145-2.c: New test.

--- gcc/tree-sra.c.jj	2013-08-14 11:02:55.290711106 +0200
+++ gcc/tree-sra.c	2013-08-14 12:00:33.311942868 +0200
@@ -1466,9 +1466,11 @@ build_ref_for_offset (location_t loc, tr
 {
   tree prev_base = base;
   tree off;
+  tree mem_ref;
   HOST_WIDE_INT base_offset;
   unsigned HOST_WIDE_INT misalign;
   unsigned int align;
+  bool is_volatile = TREE_THIS_VOLATILE (TREE_TYPE (base));
 
   gcc_checking_assert (offset % BITS_PER_UNIT == 0);
   get_object_alignment_1 (base, &align, &misalign);
@@ -1515,8 +1517,14 @@ build_ref_for_offset (location_t loc, tr
     align = (misalign & -misalign);
   if (align < TYPE_ALIGN (exp_type))
     exp_type = build_aligned_type (exp_type, align);
-
-  return fold_build2_loc (loc, MEM_REF, exp_type, base, off);
+  if (is_volatile && !TREE_THIS_VOLATILE (exp_type))
+    exp_type = build_qualified_type (exp_type, TYPE_QUALS (exp_type)
+					       | TYPE_QUAL_VOLATILE);
+
+  mem_ref = fold_build2_loc (loc, MEM_REF, exp_type, base, off);
+  if (TREE_THIS_VOLATILE (exp_type))
+    TREE_THIS_VOLATILE (mem_ref) = 1;
+  return mem_ref;
 }
 
 /* Construct a memory reference to a part of an aggregate BASE at the given
--- gcc/testsuite/gcc.dg/pr58145-1.c.jj	2013-08-14 12:02:07.077086488 +0200
+++ gcc/testsuite/gcc.dg/pr58145-1.c	2013-08-14 12:03:15.895198976 +0200
@@ -0,0 +1,37 @@
+/* PR tree-optimization/58145 */
+/* { dg-do compile { target { int32plus } } } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+struct S { unsigned int data : 32; };
+struct T { unsigned int data; };
+volatile struct S s2;
+
+void
+f1 (int val)
+{
+  struct S s = { .data = val };
+  *(volatile struct S *) 0x880000UL = s;
+}
+
+void
+f2 (int val)
+{
+  struct T t = { .data = val };
+  *(volatile struct T *) 0x880000UL = t;
+}
+
+void
+f3 (int val)
+{
+  *(volatile unsigned int *) 0x880000UL = val;
+}
+
+void
+f4 (int val)
+{
+  struct S s = { .data = val };
+  s2 = s;
+}
+
+/* { dg-final { scan-tree-dump-times " ={v} " 4 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
--- gcc/testsuite/gcc.dg/pr58145-2.c.jj	2013-08-14 12:02:28.409663559 +0200
+++ gcc/testsuite/gcc.dg/pr58145-2.c	2013-08-14 12:04:19.471612107 +0200
@@ -0,0 +1,51 @@
+/* PR tree-optimization/58145 */
+/* { dg-do compile { target { int32plus } } } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+struct S { unsigned int data : 32; };
+struct T { unsigned int data; };
+volatile struct S s2;
+
+static inline void
+f1 (int val)
+{
+  struct S s = { .data = val };
+  *(volatile struct S *) 0x880000UL = s;
+}
+
+static inline void
+f2 (int val)
+{
+  struct T t = { .data = val };
+  *(volatile struct T *) 0x880000UL = t;
+}
+
+static inline void
+f3 (int val)
+{
+  *(volatile unsigned int *) 0x880000UL = val;
+}
+
+static inline void
+f4 (int val)
+{
+  struct S s = { .data = val };
+  s2 = s;
+}
+
+void
+f5 (void)
+{
+  int i;
+  for (i = 0; i < 100; i++)
+    f1 (0);
+  for (i = 0; i < 100; i++)
+    f2 (0);
+  for (i = 0; i < 100; i++)
+    f3 (0);
+  for (i = 0; i < 100; i++)
+    f4 (0);
+}
+
+/* { dg-final { scan-tree-dump-times " ={v} " 4 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */