re PR tree-optimization/71824 (ICE when compiling libiberty with Graphite loop optimizations)

2017-02-01  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/71824
	* graphite-scop-detection.c (scop_detection::build_scop_breadth):
	Verify the loops are valid in the merged SESE region.
	(scop_detection::can_represent_loop_1): Check analyzing the
	evolution of the number of iterations in the region succeeds.

	* gcc.dg/graphite/pr71824.c: New testcase.

From-SVN: r245081

gcc/ChangeLog

+2017-02-01  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/71824
+	* graphite-scop-detection.c (scop_detection::build_scop_breadth):
+	Verify the loops are valid in the merged SESE region.
+	(scop_detection::can_represent_loop_1): Check analyzing the
+	evolution of the number of iterations in the region succeeds.
+
 2017-01-31  Ian Lance Taylor  <iant@golang.org>
 
 	* config/i386/i386.c (ix86_expand_split_stack_prologue): Add

gcc/graphite-scop-detection.c

@@ -905,7 +905,9 @@ scop_detection::build_scop_breadth (sese_l s1, loop_p loop)
 
   sese_l combined = merge_sese (s1, s2);
 
-  if (combined)
+  if (combined
+      && loop_is_valid_in_scop (loop, combined)
+      && loop_is_valid_in_scop (loop->next, combined))
     s1 = combined;
   else
     add_scop (s2);
@@ -931,6 +933,8 @@ scop_detection::can_represent_loop_1 (loop_p loop, sese_l scop)
     && niter_desc.control.no_overflow
     && (niter = number_of_latch_executions (loop))
     && !chrec_contains_undetermined (niter)
+    && !chrec_contains_undetermined (scalar_evolution_in_region (scop,
+								 loop, niter))
     && graphite_can_represent_expr (scop, loop, niter);
 }
 

gcc/testsuite/ChangeLog

+2017-02-01  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/71824
+	* gcc.dg/graphite/pr71824.c: New testcase.
+
 2017-01-31  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/79304

gcc/testsuite/gcc.dg/graphite/pr71824.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -floop-nest-optimize" } */
+
+int a, b, d;
+int **c;
+int fn1() {
+    while (a)
+      if (d) {
+	  int e = -d;
+	  for (; b < e; b++)
+	    c[b] = &a;
+      } else {
+	  for (; b; b++)
+	    c[b] = &b;
+	  d = 0;
+      }
+}