re PR tree-optimization/83089 (ICE: Segmentation fault (in instantiate_scev_name))

2017-11-22  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83089
	* tree-if-conv.c (pass_if_conversion::execute): If anything
	changed reset SCEV and free the number of iteration estimates.

	* gcc.dg/pr83089.c: New testcase.

From-SVN: r255044

gcc/ChangeLog

+2017-11-22  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/83089
+	* tree-if-conv.c (pass_if_conversion::execute): If anything
+	changed reset SCEV and free the number of iteration estimates.
+
 2017-11-21  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/82945

gcc/testsuite/ChangeLog

+2017-11-22  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/83089
+	* gcc.dg/pr83089.c: New testcase.
+
 2017-11-21  David Malcolm  <dmalcolm@redhat.com>
 
 	PR c/83056

gcc/testsuite/gcc.dg/pr83089.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-loop-if-convert -ftree-parallelize-loops=2" } */
+
+int rl, s8;
+
+void
+it (int zy, short int el)
+{
+  int hb;
+
+  while (el != 0)
+    {
+      hb = el;
+      for (rl = 0; rl < 200; ++rl)
+	{
+	  for (s8 = 0; s8 < 2; ++s8)
+	    {
+	    }
+	  if (s8 < 3)
+	    zy = hb;
+	  if (hb == 0)
+	    ++s8;
+	  zy += (s8 != -1);
+	}
+      el = zy;
+    }
+}

gcc/tree-if-conv.c

@@ -2959,6 +2959,12 @@ pass_if_conversion::execute (function *fun)
 	    && !loop->dont_vectorize))
       todo |= tree_if_conversion (loop);
 
+  if (todo)
+    {
+      free_numbers_of_iterations_estimates (fun);
+      scev_reset ();
+    }
+
   if (flag_checking)
     {
       basic_block bb;