re PR tree-optimization/56426 (Segmentation fault in find_var_scev_info, at...

re PR tree-optimization/56426 (Segmentation fault in find_var_scev_info, at tree-scalar-evolution.c:358)

2013-02-26  Marek Polacek  <polacek@redhat.com>

        PR tree-optimization/56426
        * tree-ssa-loop.c (tree_ssa_loop_init): Always call
        scev_initialize.

From-SVN: r196281

gcc/ChangeLog

+2013-02-26  Marek Polacek  <polacek@redhat.com>
+
+	PR tree-optimization/56426
+	* tree-ssa-loop.c (tree_ssa_loop_init): Always call
+	scev_initialize.
+
 2013-02-26  Richard Biener  <rguenther@suse.de>
 
 	PR target/56444

gcc/testsuite/ChangeLog

+2013-02-26  Marek Polacek  <polacek@redhat.com>
+
+	PR tree-optimization/56426
+	* gcc.dg/pr56436.c: New test.
+
 2013-02-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/56448

gcc/testsuite/gcc.dg/pr56436.c

+/* PR tree-optimization/56426 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int a, *c;
+
+void
+f (void)
+{
+  int b = 0;
+
+  for (a = 0;; a++)
+    if (--b)
+      {
+	if (a)
+	lbl:
+	  a++;
+
+	c = &b;
+	goto lbl;
+      }
+}

gcc/tree-ssa-loop.c

@@ -70,10 +70,13 @@ tree_ssa_loop_init (void)
 		       | LOOPS_HAVE_RECORDED_EXITS);
   rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
 
+  /* We might discover new loops, e.g. when turning irreducible
+     regions into reducible.  */
+  scev_initialize ();
+
   if (number_of_loops () <= 1)
     return 0;
 
-  scev_initialize ();
   return 0;
 }