tree-optimization/116810 - out-of-bound access to matches[]

The following makes sure to apply forced splitting of groups for
firced single-lane SLP only when the group being analyzed has more
than one lane.  This avoids an out-of-bound access to matches[].

	PR tree-optimization/116810
	* tree-vect-slp.cc (vect_build_slp_instance): Onlu force
	splitting for group_size > 1.

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 7161492f5114ddb589ada700e5cd91a29627eba0..ab49bb0e7ee126c9be7a7d266c7cf69e5fbcbdeb 100644 (file)
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -3715,7 +3715,7 @@ vect_build_slp_instance (vec_info *vinfo,
   unsigned i;
 
   slp_tree node = NULL;
-  if (force_single_lane)
+  if (group_size > 1 && force_single_lane)
     {
       matches[0] = true;
       matches[1] = false;