From: Andrew Stubbs <ams@codesourcery.com>
Date: Tue, 17 Dec 2019 13:01:36 +0000 (+0000)
Subject: Add pointer to PR92772
X-Git-Tag: misc/cutover-git~404
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8354bb0ebe5be8427c3795d0a32ad0564bf71489;p=thirdparty%2Fgcc.git

Add pointer to PR92772

2019-12-17  Andrew Stubbs  <ams@codesourcery.com>

	* tree-vect-loop.c (vect_create_epilog_for_reduction): Mention pr92772
	in the comments.

From-SVN: r279460
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 161768c74055..143fd48e07a1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2019-12-17  Andrew Stubbs  <ams@codesourcery.com>
+
+	* tree-vect-loop.c (vect_create_epilog_for_reduction): Mention pr92772
+	in the comments.
+
 2019-12-17  Andrew Stubbs  <ams@codesourcery.com>
 
 	* config/gcn/gcn-valu.md (extract_last_<mode>): New expander.
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 353a5ff06e14..68699f2d814c 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -4534,7 +4534,10 @@ vect_create_epilog_for_reduction (stmt_vec_info stmt_info,
      containing the last time the condition passed for that vector lane.
      The first match will be a 1 to allow 0 to be used for non-matching
      indexes.  If there are no matches at all then the vector will be all
-     zeroes.  */
+     zeroes.
+   
+     PR92772: This algorithm is broken for architectures that support
+     masked vectors, but do not provide fold_extract_last.  */
   if (STMT_VINFO_REDUC_TYPE (reduc_info) == COND_REDUCTION)
     {
       auto_vec<std::pair<tree, bool>, 2> ccompares;