re PR tree-optimization/69728 (internal compiler error: in…

re PR tree-optimization/69728 (internal compiler error: in outer_projection_mupa, at graphite-sese-to-poly.c:1175)

2017-10-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/69728
	Revert
	2017-09-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/69728
	* graphite-sese-to-poly.c (schedule_error): New global.
	(add_loop_schedule): Handle empty domain by failing the
	schedule.
	(build_original_schedule): Handle schedule_error.

	* graphite-sese-to-poly.c (add_loop_schedule): Handle empty
	domain by returning an unchanged schedule.

	* gcc.dg/graphite/pr69728.c: Adjust to reflect we can handle
	the loop now.  Remove unrelated undefined behavior.

From-SVN: r253677

gcc/ChangeLog

+2017-10-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/69728
+	Revert
+	2017-09-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/69728
+	* graphite-sese-to-poly.c (schedule_error): New global.
+	(add_loop_schedule): Handle empty domain by failing the
+	schedule.
+	(build_original_schedule): Handle schedule_error.
+
+	* graphite-sese-to-poly.c (add_loop_schedule): Handle empty
+	domain by returning an unchanged schedule.
+
 2017-10-12  Jakub Jelinek  <jakub@redhat.com>
 
 	* genrecog.c (validate_pattern): For VEC_SELECT verify that

gcc/graphite-sese-to-poly.c

@@ -1066,8 +1066,6 @@ outer_projection_mupa (__isl_take isl_union_set *set, int n)
   return isl_multi_union_pw_aff_from_union_pw_multi_aff (data.res);
 }
 
-static bool schedule_error;
-
 /* Embed SCHEDULE in the constraints of the LOOP domain.  */
 
 static isl_schedule *
@@ -1082,11 +1080,9 @@ add_loop_schedule (__isl_take isl_schedule *schedule, loop_p loop,
     return empty < 0 ? isl_schedule_free (schedule) : schedule;
 
   isl_union_set *domain = isl_schedule_get_domain (schedule);
-  /* We cannot apply an empty domain to pbbs in this loop so fail.
-     ??? Somehow drop pbbs in the loop instead.  */
+  /* We cannot apply an empty domain to pbbs in this loop so return early.  */
   if (isl_union_set_is_empty (domain))
     {
-      schedule_error = true;
       isl_union_set_free (domain);
       return schedule;
     }
@@ -1216,8 +1212,6 @@ build_schedule_loop_nest (scop_p scop, int *index, loop_p context_loop)
 static bool
 build_original_schedule (scop_p scop)
 {
-  schedule_error = false;
-
   int i = 0;
   int n = scop->pbbs.length ();
   while (i < n)
@@ -1232,14 +1226,6 @@ build_original_schedule (scop_p scop)
       scop->original_schedule = add_in_sequence (scop->original_schedule, s);
     }
 
-  if (schedule_error)
-    {
-      if (dump_file)
-	fprintf (dump_file, "[sese-to-poly] failed to build "
-		 "original schedule\n");
-      return false;
-    }
-
   if (dump_file)
     {
       fprintf (dump_file, "[sese-to-poly] original schedule:\n");

gcc/testsuite/ChangeLog

+2017-10-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/69728
+	* gcc.dg/graphite/pr69728.c: Adjust to reflect we can handle
+	the loop now.  Remove unrelated undefined behavior.
+
 2017-10-12  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/82159

gcc/testsuite/gcc.dg/graphite/pr69728.c

 /* { dg-do compile } */
-/* { dg-options "-O3 -floop-nest-optimize" } */
+/* { dg-options "-O3 -floop-nest-optimize -fdump-tree-graphite-details" } */
 
-int a[1];
+int a[9];
 int b, c, d, e;
 void
 fn1 ()
@@ -19,3 +19,9 @@ fn1 ()
 	}
     }
 }
+
+/* At the moment only ISL figures that if (d) is always true.  We've
+   run into scheduling issues before here, not being able to handle
+   empty domains.  */
+
+/* { dg-final { scan-tree-dump "loop nest optimized" "graphite" } }  */