gcc/gcc48-ppc32-retaddr.patch

2005-11-28  Jakub Jelinek  <jakub@redhat.com>

	* config/rs6000/rs6000.c (rs6000_return_addr): If COUNT == 0,
	read word RETURN_ADDRESS_OFFSET bytes above arg_pointer_rtx
	instead of doing an extran indirection from frame_pointer_rtx.

	* gcc.dg/20051128-1.c: New test.

--- gcc/config/rs6000/rs6000.c.jj	2005-11-26 14:38:01.000000000 +0100
+++ gcc/config/rs6000/rs6000.c	2005-11-28 20:32:18.000000000 +0100
@@ -18325,18 +18325,22 @@ rs6000_return_addr (int count, rtx frame
      don't try to be too clever here.  */
   if (count != 0 || (DEFAULT_ABI != ABI_AIX && flag_pic))
     {
+      rtx x;
       cfun->machine->ra_needs_full_frame = 1;
 
-      return
-	gen_rtx_MEM
-	  (Pmode,
-	   memory_address
-	   (Pmode,
-	    plus_constant (Pmode,
-			   copy_to_reg
-			   (gen_rtx_MEM (Pmode,
-					 memory_address (Pmode, frame))),
-			   RETURN_ADDRESS_OFFSET)));
+      if (count == 0)
+	{
+	  gcc_assert (frame == frame_pointer_rtx);
+	  x = arg_pointer_rtx;
+	}
+      else
+	{
+	  x = memory_address (Pmode, frame);
+	  x = copy_to_reg (gen_rtx_MEM (Pmode, x));
+	}
+
+      x = plus_constant (Pmode, x, RETURN_ADDRESS_OFFSET);
+      return gen_rtx_MEM (Pmode, memory_address (Pmode, x));
     }
 
   cfun->machine->ra_need_lr = 1;
--- gcc/testsuite/gcc.dg/20051128-1.c.jj	2005-10-10 11:21:41.096999000 +0200
+++ gcc/testsuite/gcc.dg/20051128-1.c	2005-11-28 12:30:57.000000000 +0100
@@ -0,0 +1,41 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fpic" } */
+
+extern void exit (int);
+extern void abort (void);
+
+int b;
+
+struct A
+{
+  void *pad[147];
+  void *ra, *h;
+  long o;
+};
+
+void
+__attribute__((noinline))
+foo (struct A *a, void *x)
+{
+  __builtin_memset (a, 0, sizeof (a));
+  if (!b)
+    exit (0);
+}
+
+void
+__attribute__((noinline))
+bar (void)
+{
+  struct A a;
+
+  __builtin_unwind_init ();
+  foo (&a, __builtin_return_address (0));
+}
+
+int
+main (void)
+{
+  bar ();
+  abort ();
+  return 0;
+}