re PR tree-optimization/81118 (ice in remove_redundant_iv_tests)

2017-06-19  Richard Biener  <rguenther@suse.de>

	PR middle-end/81118
	* tree-cfgcleanup.c (cleanup_tree_cfg_noloop): Clear niter
	estimates if we changed anything.

	* gcc.dg/torture/pr81118.c: New testcase.

From-SVN: r249374

gcc/ChangeLog

 2017-06-19  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/81118
+	* tree-cfgcleanup.c (cleanup_tree_cfg_noloop): Clear niter
+	estimates if we changed anything.
+
+2017-06-19  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/80887
 	* tree-ssa-sccvn.c (mprts_hook_cnt): New global.
 	(vn_lookup_simplify_result): Allow only mprts_hook_cnt succesful

gcc/testsuite/ChangeLog

 2017-06-19  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/81118
+	* gcc.dg/torture/pr81118.c: New testcase.
+
+2017-06-19  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/80887
 	* gcc.dg/tree-ssa/pr80887.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr81118.c

+/* { dg-do compile } */
+/* { dg-additional-options "-w" } */
+
+int a[7], b;
+int c()
+{
+  int d, e;
+  for (; d; d++)
+    if (a[d])
+      if (b)
+	return;
+      else if (d >= e)
+	return 0;
+}

gcc/tree-cfgcleanup.c

@@ -839,7 +839,12 @@ cleanup_tree_cfg_noloop (void)
   timevar_pop (TV_TREE_CLEANUP_CFG);
 
   if (changed && current_loops)
+    {
+      /* Removing edges and/or blocks may make recorded bounds refer
+         to stale GIMPLE stmts now, so clear them.  */
+      free_numbers_of_iterations_estimates (cfun);
       loops_state_set (LOOPS_NEED_FIXUP);
+    }
 
   return changed;
 }