From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1666) id 862353851171; Thu, 20 Oct 2022 10:50:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 862353851171 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1666263003; bh=63qwM1mVV7Tm+2z5EFhF422JdDAfpi50kTYG3SEto0o=; h=From:To:Subject:Date:From; b=EpoPyU8i/3/tjVqOXLra2SSI9MH9/8KGuefG4y+WZsuMCgdyEwWXmlFVsDF+85xVF IR3RD65dsOeXFvnItZXLlOSwQJQIJ3BWN8zdnjckQ2HANzFh+imvS19NRxUe4BYETH rauthlTeqGBnIGnXWNpGbKqjb8BRWd6gIyxC6b/c= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Richard Biener To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-3406] Avoid PHI - PHI recurrence in vectorization X-Act-Checkin: gcc X-Git-Author: Richard Biener X-Git-Refname: refs/heads/master X-Git-Oldrev: c7ebee2378426eeca425ca5406af213a926f154c X-Git-Newrev: 5362b5cc8dba9de70904613fff1d5391a9c087ce Message-Id: <20221020105003.862353851171@sourceware.org> Date: Thu, 20 Oct 2022 10:50:03 +0000 (GMT) List-Id: https://gcc.gnu.org/g:5362b5cc8dba9de70904613fff1d5391a9c087ce commit r13-3406-g5362b5cc8dba9de70904613fff1d5391a9c087ce Author: Richard Biener Date: Thu Oct 20 11:04:21 2022 +0200 Avoid PHI - PHI recurrence in vectorization The reported regression of libgomp loop-14.C shows that there isn't generally a good reliable place to insert the permute upfront so the following simply restricts recurrence vectorization to the cases where the latch value isn't defined by a PHI. * tree-vect-loop.cc (vect_phi_first_order_recurrence_p): Disallow latch PHI defs. (vectorizable_recurr): Revert previous change. Diff: --- gcc/tree-vect-loop.cc | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc index 92790bd8095..d5c2bff80be 100644 --- a/gcc/tree-vect-loop.cc +++ b/gcc/tree-vect-loop.cc @@ -543,6 +543,7 @@ vect_phi_first_order_recurrence_p (loop_vec_info loop_vinfo, class loop *loop, tree ldef = PHI_ARG_DEF_FROM_EDGE (phi, latch); if (TREE_CODE (ldef) != SSA_NAME || SSA_NAME_IS_DEFAULT_DEF (ldef) + || is_a (SSA_NAME_DEF_STMT (ldef)) || !flow_bb_inside_loop_p (loop, gimple_bb (SSA_NAME_DEF_STMT (ldef)))) return false; @@ -8486,14 +8487,8 @@ vectorizable_recurr (loop_vec_info loop_vinfo, stmt_vec_info stmt_info, vectorized the latch definition. */ edge le = loop_latch_edge (LOOP_VINFO_LOOP (loop_vinfo)); gimple *latch_def = SSA_NAME_DEF_STMT (PHI_ARG_DEF_FROM_EDGE (phi, le)); - gimple_stmt_iterator gsi2; - if (is_a (latch_def)) - gsi2 = gsi_after_labels (gimple_bb (latch_def)); - else - { - gsi2 = gsi_for_stmt (latch_def); - gsi_next (&gsi2); - } + gimple_stmt_iterator gsi2 = gsi_for_stmt (latch_def); + gsi_next (&gsi2); for (unsigned i = 0; i < ncopies; ++i) {