re PR c/87953 (asan: stack-buffer-overflow in vectorizable_reduction)

2018-11-09  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/87953
	* tree-vect-loop.c (vectorizable_reduction): For analysis
	always pass ops[0] to vectorizable_condition.

From-SVN: r265964

gcc/ChangeLog

+2018-11-09  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/87953
+	* tree-vect-loop.c (vectorizable_reduction): For analysis
+	always pass ops[0] to vectorizable_condition.
+
 2018-11-09  Stafford Horne  <shorne@gmail.com>
 	    Richard Henderson  <rth@twiddle.net>
 	    Joel Sherrill  <joel@rtems.org>

gcc/tree-vect-loop.c

@@ -6485,9 +6485,10 @@ vectorizable_reduction (stmt_vec_info stmt_info, gimple_stmt_iterator *gsi,
   if (code == COND_EXPR)
     {
       /* Only call during the analysis stage, otherwise we'll lose
-	 STMT_VINFO_TYPE.  */
+	 STMT_VINFO_TYPE.  We'll pass ops[0] as reduc_op, it's only
+	 used as a flag during analysis.  */
       if (!vec_stmt && !vectorizable_condition (stmt_info, gsi, NULL,
-						ops[reduc_index], 0, NULL,
+						ops[0], 0, NULL,
 						cost_vec))
         {
           if (dump_enabled_p ())