[PATCH] Fix off by one error in loop-unroll.c (PR rtl-optimization/82675).

[Martin Liška]

Hello.

Following patch fixes off by one in loop unroller where wont_exit has
not enough elements that are later on asked for.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

Ready to be installed?
Martin

gcc/ChangeLog:

2017-11-08  Martin Liska  <mli...@suse.cz>

        PR rtl-optimization/82675
        * loop-unroll.c (unroll_loop_constant_iterations): Allocate one
        more element in sbitmap.
---
 gcc/loop-unroll.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)



diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c
index 91bf5dddeed..2fab92bcf74 100644
--- a/gcc/loop-unroll.c
+++ b/gcc/loop-unroll.c
@@ -477,7 +477,7 @@ unroll_loop_constant_iterations (struct loop *loop)
 
   exit_mod = niter % (max_unroll + 1);
 
-  auto_sbitmap wont_exit (max_unroll + 1);
+  auto_sbitmap wont_exit (max_unroll + 2);
   bitmap_ones (wont_exit);
 
   auto_vec<edge> remove_edges;