From: Richard Biener <rguenther@suse.de>
Date: Fri, 7 Jun 2024 07:41:11 +0000 (+0200)
Subject: Fix fold-left reduction vectorization with multiple stmt copies
X-Git-Tag: basepoints/gcc-16~8456
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dd6f942c266533b2f72610f354bc9184f8276beb;p=thirdparty%2Fgcc.git

Fix fold-left reduction vectorization with multiple stmt copies

There's a typo when code generating the mask operand for conditional
fold-left reductions in the case we have multiple stmt copies.  The
latter is now allowed for SLP and possibly disabled for non-SLP by
accident.

This fixes the observed run-FAIL for
gcc.dg/vect/vect-cond-reduc-in-order-2-signed-zero.c with AVX512
and 256bit sized vectors.

	* tree-vect-loop.cc (vectorize_fold_left_reduction): Fix
	mask vector operand indexing.
---

diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index ceb92156b58..028692614bb 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -7217,7 +7217,7 @@ vectorize_fold_left_reduction (loop_vec_info loop_vinfo,
       if (LOOP_VINFO_FULLY_MASKED_P (loop_vinfo))
 	mask = vect_get_loop_mask (loop_vinfo, gsi, masks, vec_num, vectype_in, i);
       else if (is_cond_op)
-	mask = vec_opmask[0];
+	mask = vec_opmask[i];
       if (LOOP_VINFO_FULLY_WITH_LENGTH_P (loop_vinfo))
 	{
 	  len = vect_get_loop_len (loop_vinfo, gsi, lens, vec_num, vectype_in,