re PR middle-end/37284 (ICE on valid code with -fstrict-aliasing)

2008-09-18  Richard Guenther  <rguenther@suse.de>

	PR middle-end/37284
	* tree-cfg.c (remove_useless_stmts_1): Remove
	GIMPLE_CHANGE_DYNAMIC_TYPE if not optimizing.

	* g++.dg/tree-ssa/pr37284.C: New testcase.

From-SVN: r140453

gcc/ChangeLog

+2008-09-18  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/37284
+	* tree-cfg.c (remove_useless_stmts_1): Remove
+	GIMPLE_CHANGE_DYNAMIC_TYPE if not optimizing.
+
 2008-09-18  Nick Clifton  <nickc@redhat.com>
 
 	* config/frv/frv.h (IRA_COVER_CLASSES): Define.

gcc/testsuite/ChangeLog

+2008-09-18  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/37284
+	* g++.dg/tree-ssa/pr37284.C: New testcase.
+
 2008-09-18  Daniel Kraft  <d@domob.eu>
 
 	PR fortran/37507

gcc/testsuite/g++.dg/tree-ssa/pr37284.C

+/* { dg-do compile } */
+/* { dg-options "-fstrict-aliasing" } */
+
+void* operator new(__SIZE_TYPE__, void* __p) throw()
+{
+  return __p;
+}
+
+class PatternDriverTop;
+
+typedef const PatternDriverTop* _Tp;
+
+void construct(_Tp* __p, const _Tp& __val)
+{
+  ::new((void *)__p) _Tp(__val);
+}
+

gcc/tree-cfg.c

@@ -1997,6 +1997,18 @@ remove_useless_stmts_1 (gimple_stmt_iterator *gsi, struct rus_data *data)
           }
           break;
 
+        case GIMPLE_CHANGE_DYNAMIC_TYPE:
+	  /* If we do not optimize remove GIMPLE_CHANGE_DYNAMIC_TYPE as
+	     expansion is confused about them and we only remove them
+	     during alias computation otherwise.  */
+	  if (!optimize)
+	    {
+	      data->last_was_goto = false;
+	      gsi_remove (gsi, false);
+	      break;
+	    }
+	  /* Fallthru.  */
+
         default:
           data->last_was_goto = false;
           gsi_next (gsi);