re PR rtl-optimization/58365 (likely wrong code bug)

	PR rtl-optimization/58365
	* cfgcleanup.c (merge_memattrs): Also clear MEM_READONLY_P
	resp. MEM_NOTRAP_P if they differ, or set MEM_VOLATILE_P if
	it differs.

	* gcc.c-torture/execute/pr58365.c: New test.

From-SVN: r202434

gcc/ChangeLog

+2013-09-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/58365
+	* cfgcleanup.c (merge_memattrs): Also clear MEM_READONLY_P
+	resp. MEM_NOTRAP_P if they differ, or set MEM_VOLATILE_P if
+	it differs.
+
 2013-09-10  Richard Biener  <rguenther@suse.de>
 
 	* tree-data-ref.h (build_rdg): Drop all parameters but loop.

gcc/cfgcleanup.c

@@ -925,6 +925,24 @@ merge_memattrs (rtx x, rtx y)
 	  set_mem_align (y, MEM_ALIGN (x));
 	}
     }
+  if (code == MEM)
+    {
+      if (MEM_READONLY_P (x) != MEM_READONLY_P (y))
+	{
+	  MEM_READONLY_P (x) = 0;
+	  MEM_READONLY_P (y) = 0;
+	}
+      if (MEM_NOTRAP_P (x) != MEM_NOTRAP_P (y))
+	{
+	  MEM_NOTRAP_P (x) = 0;
+	  MEM_NOTRAP_P (y) = 0;
+	}
+      if (MEM_VOLATILE_P (x) != MEM_VOLATILE_P (y))
+	{
+	  MEM_VOLATILE_P (x) = 1;
+	  MEM_VOLATILE_P (y) = 1;
+	}
+    }
 
   fmt = GET_RTX_FORMAT (code);
   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)

gcc/testsuite/ChangeLog

+2013-09-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/58365
+	* gcc.c-torture/execute/pr58365.c: New test.
+
 2013-09-10  Michael Zolotukhin  <michael.v.zolotukhin@gmail.com>
 
 	* gcc.dg/torture/memcpy-1.c: New test.

gcc/testsuite/gcc.c-torture/execute/pr58365.c

+/* PR rtl-optimization/58365 */
+
+extern void abort (void);
+
+struct S
+{
+  volatile int a;
+  int b, c, d, e;
+} f;
+static struct S g, h;
+int i = 1;
+
+char
+foo (void)
+{
+  return i;
+}
+
+static struct S
+bar (void)
+{
+  if (foo ())
+    return f;
+  return g;
+}
+
+int
+main ()
+{
+  h = bar ();
+  f.b = 1;
+  if (h.b != 0)
+    abort ();
+  return 0;
+}