From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-498517-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 114223 invoked by alias); 1 Oct 2015 15:48:29 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 114019 invoked by uid 48); 1 Oct 2015 15:48:21 -0000
From: "afomin.mailbox at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/67800] New: [6 Regression] Missed vectorization opportunity on x86
Date: Thu, 01 Oct 2015 15:48:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 6.0
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: afomin.mailbox at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution:
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter cc target_milestone cf_gcctarget attachments.created
Message-ID: <bug-67800-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-10/txt/msg00072.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67800

            Bug ID: 67800
           Summary: [6 Regression] Missed vectorization opportunity on x86
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: afomin.mailbox at gmail dot com
                CC: izamyatin at gmail dot com, rguenth at gcc dot gnu.org,
                    ysrumyan at gmail dot com
  Target Milestone: ---
            Target: i686-*-*

Created attachment 36434
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36434&action=edit
A reproducer

A loop in the test attached compiled with -m32 -msse4.2 -O2 -ftree-vectorize
-fPIE -pie -c is no more vectorized after r223525 (while on r223524 everything
is OK) because of strange DOT_PROD_EXPR recognition (see below).

vect_is_simple_use: operand _15
def_stmt: _15 = _14 * 76;
type of def: internal
vect_recog_dot_prod_pattern: detected: patt_47 = DOT_PROD_EXPR <_2, 76, _17>;
pattern recognized: patt_47 = DOT_PROD_EXPR <_2, 76, _17>;