From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-486087-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 126389 invoked by alias); 12 May 2015 10:11:57 -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 126047 invoked by uid 48); 12 May 2015 10:11:53 -0000
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/66119] [5/6 Regression] in optimization of avx-code
Date: Tue, 12 May 2015 10:11:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 5.1.1
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution:
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 5.2
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-66119-4-1XxvNxSlGt@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-66119-4@http.gcc.gnu.org/bugzilla/>
References: <bug-66119-4@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: 2015-05/txt/msg00927.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66119

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  We expand from

  <bb 2>:
  a$data_13 = MEM[(struct Vec2 *)&a];
  a$32$data_14 = MEM[(struct Vec2 *)&a + 32B];
  b = b;
  v2_15 = MEM[(struct Vec2 *)&b];
  v2$32_16 = MEM[(struct Vec2 *)&b + 32B];
  _7 = a$32$data_14 + v2$32_16;
  _10 = a$data_13 + v2_15;
  MEM[(struct Vec2 *)&<retval>] = _10;
  MEM[(struct Vec2 *)&<retval> + 32B] = _7;
  return <retval>;

in GCC 5 (note the b = b assignment) while 4.9 sees

  <bb 2>:
  a$data_4 = MEM[(struct Vec2 *)&a];
  a$32$data_13 = MEM[(struct Vec2 *)&a + 32B];
  v2_14 = MEM[(struct Vec2 *)&b];
  v2$32_15 = MEM[(struct Vec2 *)&b + 32B];
  _7 = a$32$data_13 + v2$32_15;
  _10 = a$data_4 + v2_14;
  MEM[(struct Vec2 *)&<retval>] = _10;
  MEM[(struct Vec2 *)&<retval> + 32B] = _7;
  return <retval>;