re PR tree-optimization/39202 (internal compiler error: in collapse_rest_of_var,…

re PR tree-optimization/39202 (internal compiler error: in collapse_rest_of_var, at tree-ssa-structalias.c:3296)

2009-02-17  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/39202
	* tree-ssa-structalias.c (do_structure_copy): Before collapsing
	a var make sure to follow existing collapses.

	* gcc.c-torture/compile/pr39202.c: New testcase.

From-SVN: r144235

gcc/ChangeLog

 2009-02-17  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/39202
+	* tree-ssa-structalias.c (do_structure_copy): Before collapsing
+	a var make sure to follow existing collapses.
+
+2009-02-17  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/39214
 	* langhooks.c (lhd_print_error_function): Check for NULL block.
 

gcc/testsuite/ChangeLog

 2009-02-17  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/39202
+	* gcc.c-torture/compile/pr39202.c: New testcase.
+
+2009-02-17  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/39204
 	* gcc.dg/torture/pr39204.c: New testcase.
 

gcc/testsuite/gcc.c-torture/compile/pr39202.c

+typedef struct
+{
+  union
+    {
+      int * aaa;
+    } u;
+} t_a;
+
+typedef struct
+{
+  unsigned bbb : 1;
+} t_b;
+
+typedef struct
+{
+  int ccc;
+  t_a ddd;
+  t_b eee;
+  int fff;
+} t_c;
+
+typedef struct t_d
+{
+  t_c f1;
+  t_c f2;
+} t_d;
+
+void foo (void)
+{
+  t_d ggg;
+  ggg.f1 = ggg.f2;
+}
+

gcc/tree-ssa-structalias.c

@@ -3405,8 +3405,8 @@ do_structure_copy (tree lhsop, tree rhsop)
 	{
 	  if (!do_simple_structure_copy (lhs, rhs, MIN (lhssize, rhssize)))
 	    {
-	      lhs.var = collapse_rest_of_var (lhs.var);
-	      rhs.var = collapse_rest_of_var (rhs.var);
+	      lhs.var = collapse_rest_of_var (get_varinfo_fc (lhs.var)->id);
+	      rhs.var = collapse_rest_of_var (get_varinfo_fc (rhs.var)->id);
 	      lhs.offset = 0;
 	      rhs.offset = 0;
 	      lhs.type = SCALAR;