[PATCH] Fix PR51436

[Richard Guenther <rguenther at suse dot de>]

Tested on x86_64-unknown-linux-gnu, applied as obvious.

Richard.

2011-12-06  Richard Guenther  <rguenther@suse.de>

	PR middle-end/51436
	* gimple-fold.c (gimplify_and_update_call_from_tree): Guard
	vdef check for the fact we do not have virtual operands when
	not optimizing.

	* g++.dg/torture/pr51436.C: New testcase.

Index: gcc/gimple-fold.c
===================================================================
*** gcc/gimple-fold.c	(revision 182041)
--- gcc/gimple-fold.c	(working copy)
*************** gimplify_and_update_call_from_tree (gimp
*** 600,606 ****
  	  else
  	    vdef = make_ssa_name (gimple_vop (cfun), new_stmt);
  	  gimple_set_vdef (new_stmt, vdef);
! 	  if (TREE_CODE (vdef) == SSA_NAME)
  	    SSA_NAME_DEF_STMT (vdef) = new_stmt;
  	  laststore = new_stmt;
  	}
--- 600,606 ----
  	  else
  	    vdef = make_ssa_name (gimple_vop (cfun), new_stmt);
  	  gimple_set_vdef (new_stmt, vdef);
! 	  if (vdef && TREE_CODE (vdef) == SSA_NAME)
  	    SSA_NAME_DEF_STMT (vdef) = new_stmt;
  	  laststore = new_stmt;
  	}
Index: gcc/testsuite/g++.dg/torture/pr51436.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr51436.C	(revision 0)
--- gcc/testsuite/g++.dg/torture/pr51436.C	(revision 0)
***************
*** 0 ****
--- 1,60 ----
+ /* { dg-do compile } */
+ 
+ typedef __SIZE_TYPE__ size_t;
+ extern "C" void *memcpy (void *, __const void *, size_t);
+ template < class Dest, class Source > struct BitCastHelper {
+     static Dest cast (const Source & source) __attribute__ ((always_inline)) {
+ 	Dest dest;
+ 	memcpy (0, &source, sizeof dest);
+     }
+ };
+ template < class Dest, class Source > Dest BitCast (Source)
+ {
+   BitCastHelper < Dest, Source >::cast (0);
+ }
+ 
+ class MaybeObject
+ {
+ };
+ class Object:MaybeObject
+ {
+ public:
+     static Object *cast (Object *) {
+     }
+ };
+ class HeapObject:public Object
+ {
+ };
+ class String:public HeapObject
+ {
+ };
+ class ExternalString:public String
+ {
+ };
+ class ExternalTwoByteString:public ExternalString
+ {
+ };
+ 
+ template < typename T > class Handle
+ {
+ public:
+     Handle () {
+     }
+     T *operator* () const;
+     template < class S > static Handle < T > cast (Handle < S > that) {
+ 	T::cast (*that);
+     }
+     T **location_;
+ };
+ 
+ template < typename T > T * Handle < T >::operator* () const
+ {
+   *BitCast < T ** >(location_);
+ }
+ 
+ void
+ TestCharacterStream ()
+ {
+   Handle < String > uc16_string;
+   Handle < ExternalTwoByteString >::cast (uc16_string);
+ }