re PR tree-optimization/68817 (internal compiler error: Segmentation fault (program f951))

2015-12-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68817
	* tree-vect-slp.c (vect_attempt_slp_rearrange_stmts): Detect
	gaps early.

	* gfortran.dg/pr68817.f90: New testcase.

From-SVN: r231508

gcc/ChangeLog

+2015-12-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68817
+	* tree-vect-slp.c (vect_attempt_slp_rearrange_stmts): Detect
+	gaps early.
+
 2015-12-10  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	* tree-vect-stmts.c (vectorizable_assignment): Support

gcc/testsuite/ChangeLog

+2015-12-10  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68817
+	* gfortran.dg/pr68817.f90: New testcase.
+
 2015-12-10  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	Revert [testsuite][ARM target attributes] Fix effective_target tests

gcc/testsuite/gfortran.dg/pr68817.f90

+! { dg-do compile }
+! { dg-options "-O3 -ffast-math" }
+      SUBROUTINE TEST(A,B,C)
+      DIMENSION B(3),C(1000,10)
+      DO I = 1,3
+         I3=I*3
+         B(1) = B(1) + (C(K,I3+1)-A)
+         B(3) = B(3) + (C(K,I3+3)-A)
+      ENDDO
+      END
+

gcc/tree-vect-slp.c

@@ -1237,6 +1237,8 @@ vect_attempt_slp_rearrange_stmts (slp_instance slp_instn)
   bitmap_clear (load_index);
   FOR_EACH_VEC_ELT (node->load_permutation, i, lidx)
     {
+      if (lidx >= group_size)
+	return false;
       if (bitmap_bit_p (load_index, lidx))
 	{
 	  sbitmap_free (load_index);