cfgexpand.c (expand_debug_expr): Fail if bitpos < 0 for non-MEM op0.

	* cfgexpand.c (expand_debug_expr): Fail if bitpos < 0 for non-MEM
	op0.

	* gcc.dg/debug/vta-3.c: New test.

From-SVN: r152972

gcc/ChangeLog

-2009-10-17  Andy Hutchinson <hutchinsonandy@gcc.gnu.org>
+2009-10-19  Jakub Jelinek  <jakub@redhat.com>
+
+	* cfgexpand.c (expand_debug_expr): Fail if bitpos < 0 for non-MEM
+	op0.
+
+2009-10-17  Andy Hutchinson  <hutchinsonandy@gcc.gnu.org>
 
 	PR middle-end/41738
 	* optabs.c (expand_binop): Make mode of shift count expression mode

gcc/cfgexpand.c

@@ -2593,6 +2593,9 @@ expand_debug_expr (tree exp)
 	if (bitpos == 0 && mode == GET_MODE (op0))
 	  return op0;
 
+        if (bitpos < 0)
+          return NULL;
+
 	if ((bitpos % BITS_PER_UNIT) == 0
 	    && bitsize == GET_MODE_BITSIZE (mode1))
 	  {

gcc/testsuite/ChangeLog

+2009-10-19  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.dg/debug/vta-3.c: New test.
+
 2009-10-17  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/nested_proc.adb: Rename into...

gcc/testsuite/gcc.dg/debug/vta-3.c

+/* { dg-do compile } */
+
+int
+foo (void)
+{
+  union { char e[8]; int i; } a, b;
+  char *c, *d;
+  unsigned int i;
+  c = a.e;
+  d = &b.e[sizeof (int) - 1];
+  for (i = 0; i < sizeof (int); i++)
+    {
+      *d = *c++;
+      --d;
+    }
+  return b.i;
+}