2008-04-15  Jakub Jelinek  <jakub@redhat.com>

	PR c/35739
	* tree-nrv.c (tree_nrv): Don't optimize if result_type is GIMPLE
	reg type.

	* gcc.dg/dfp/pr35739.c: New test.

--- gcc/tree-nrv.c.jj	2008-04-04 15:12:00.000000000 +0200
+++ gcc/tree-nrv.c	2008-04-15 20:00:07.000000000 +0200
@@ -1,5 +1,5 @@
 /* Language independent return value optimizations
-   Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -115,6 +115,11 @@ tree_nrv (void)
   if (!aggregate_value_p (result, current_function_decl))
     return 0;
 
+  /* If a GIMPLE type is returned in memory, finalize_nrv_r might create
+     non-GIMPLE.  */
+  if (is_gimple_reg_type (result_type))
+    return 0;
+
   /* Look through each block for assignments to the RESULT_DECL.  */
   FOR_EACH_BB (bb)
     {
--- gcc/testsuite/gcc.dg/dfp/pr35739.c.jj	2008-04-15 20:02:55.000000000 +0200
+++ gcc/testsuite/gcc.dg/dfp/pr35739.c	2008-04-15 20:18:15.000000000 +0200
@@ -0,0 +1,16 @@
+/* PR c/35739 */
+/* { dg-do compile { target *-*-linux* } } */
+/* { dg-options "-O -fpreprocessed -fmudflap" } */
+
+_Decimal128
+foo (int n, ...)
+{
+  int i;
+  _Decimal128 j = 0;
+  __builtin_va_list ap;
+  __builtin_va_start (ap, n);
+  for (i = 0; i < n; i++)
+    j += __builtin_va_arg (ap, _Decimal128);
+  __builtin_va_end (ap);
+  return j;
+}