From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-489180-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 69872 invoked by alias); 17 Jun 2015 12:59:13 -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 69839 invoked by uid 48); 17 Jun 2015 12:59:10 -0000
From: "alalaw01 at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/65952] [AArch64] Will not vectorize storing induction of pointer addresses for LP64
Date: Wed, 17 Jun 2015 12:59:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 5.1.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: alalaw01 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: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-65952-4-gJFITY2t9V@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-65952-4@http.gcc.gnu.org/bugzilla/>
References: <bug-65952-4@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: 2015-06/txt/msg01512.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65952

--- Comment #5 from alalaw01 at gcc dot gnu.org ---
So the above example tends to get fully unrolled, but even on an example with
32 ptrs rather than 4, yes the vectorizer fails because of the multiplication -
but the multiplication is gone by the final tree stage, as it's strength
reduced down to an add; I believe this -fdump-tree-optimized would be perfectly
vectorizable:

loop ()
{
  unsigned long ivtmp.12;
  unsigned long ivtmp.10;
  void * _4;
  struct my_struct * _7;
  struct my_struct * pretmp_11;
  unsigned long _20;

  <bb 2>:
  pretmp_11 = array;
  ivtmp.10_16 = (unsigned long) pretmp_11;
  ivtmp.12_2 = (unsigned long) &ptrs;
  _20 = (unsigned long) &MEM[(void *)&ptrs + 256B];

  <bb 3>:
  # ivtmp.10_10 = PHI <ivtmp.10_1(3), ivtmp.10_16(2)>
  # ivtmp.12_15 = PHI <ivtmp.12_14(3), ivtmp.12_2(2)>
  _7 = (struct my_struct *) ivtmp.10_10;
  _4 = (void *) ivtmp.12_15;
  MEM[base: _4, offset: 0B] = _7;
  ivtmp.10_1 = ivtmp.10_10 + 16;
  ivtmp.12_14 = ivtmp.12_15 + 8;
  if (ivtmp.12_14 != _20)
    goto <bb 3>;
  else
    goto <bb 4>;

  <bb 4>:
  return;

}