re PR tree-optimization/83563 ([graphite] ICE: Segmentation fault (in instantiate_scev_r))

2018-01-08  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83563
	* graphite.c (canonicalize_loop_closed_ssa_form): Reset the SCEV
	cache.

	* gcc.dg/graphite/pr83563.c: New testcase.

From-SVN: r256343

gcc/ChangeLog

 2018-01-08  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/83563
+	* graphite.c (canonicalize_loop_closed_ssa_form): Reset the SCEV
+	cache.
+
+2018-01-08  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/83713
 	* convert.c (do_narrow): Properly guard TYPE_OVERFLOW_WRAPS checks.
 

gcc/graphite.c

@@ -322,6 +322,10 @@ canonicalize_loop_closed_ssa_form (void)
   FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
     canonicalize_loop_closed_ssa (loop);
 
+  /* We can end up releasing duplicate exit PHIs and also introduce
+     additional copies so the cached information isn't correct anymore.  */
+  scev_reset ();
+
   checking_verify_loop_closed_ssa (true);
 }
 

gcc/testsuite/ChangeLog

 2018-01-08  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/83563
+	* gcc.dg/graphite/pr83563.c: New testcase.
+
+2018-01-08  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/83713
 	* g++.dg/torture/pr83713.C: New testcase.
 

gcc/testsuite/gcc.dg/graphite/pr83563.c

+/* { dg-do compile } */
+/* { dg-options "-O -fgraphite -ftree-loop-distribution -fno-tree-dominator-opts -fno-tree-sink -fno-tree-dce" } */
+
+void
+sy (void)
+{
+  int hb;
+
+  for (hb = 1; hb != 0; hb += hb)
+    {
+    }
+
+  while (hb < 1)
+    ++hb;
+}