From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-patches-return-406511-listarch-gcc-patches=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 31528 invoked by alias); 2 Sep 2015 12:32:53 -0000
Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-patches.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-patches/>
List-Post: <mailto:gcc-patches@gcc.gnu.org>
List-Help: <mailto:gcc-patches-help@gcc.gnu.org>
Sender: gcc-patches-owner@gcc.gnu.org
Received: (qmail 31515 invoked by uid 89); 2 Sep 2015 12:32:52 -0000
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2
X-HELO: mail-yk0-f173.google.com
Received: from mail-yk0-f173.google.com (HELO mail-yk0-f173.google.com) (209.85.160.173) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Wed, 02 Sep 2015 12:32:47 +0000
Received: by ykcf206 with SMTP id f206so7469715ykc.3        for <gcc-patches@gcc.gnu.org>; Wed, 02 Sep 2015 05:32:45 -0700 (PDT)
MIME-Version: 1.0
X-Received: by 10.170.100.137 with SMTP id r131mr3237470yka.20.1441197165216; Wed, 02 Sep 2015 05:32:45 -0700 (PDT)
Received: by 10.37.93.136 with HTTP; Wed, 2 Sep 2015 05:32:45 -0700 (PDT)
In-Reply-To: <000c01d0e532$823066c0$86913440$@arm.com>
References: <000c01d0e532$823066c0$86913440$@arm.com>
Date: Wed, 02 Sep 2015 12:32:00 -0000
Message-ID: <CAFiYyc0R-1QjWqz9WKydr9wRUdLdv9oPtBFXUo64TNeoFF1o9A@mail.gmail.com>
Subject: Re: [PATCH GCC]Look into unnecessary conversion when checking mult_op in get_shiftadd_cost
From: Richard Biener <richard.guenther@gmail.com>
To: Bin Cheng <bin.cheng@arm.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Content-Type: text/plain; charset=UTF-8
X-IsSubscribed: yes
X-SW-Source: 2015-09/txt/msg00136.txt.bz2

On Wed, Sep 2, 2015 at 5:50 AM, Bin Cheng <bin.cheng@arm.com> wrote:
> Hi,
> When calling get_shiftadd_cost, the mult_op is stripped at caller places.
> We should look into unnecessary conversion in op1 before checking equality,
> otherwise it computes wrong shiftadd cost.  This patch picks this small
> issue up.
>
> Bootstrap and test on x86_64 and aarch64 along with other patches.  Is it
> OK?

Just do STRIP_NOPS (op1) unconditionally?  Thus

  STRIP_NOPS (op1);
  mult_in_op1 = operand_equal_p (op1, mult, 0);

ok with that change.

Thanks,
Richard.

> Thanks,
> bin
>
> 2015-08-31  Bin Cheng  <bin.cheng@arm.com>
>
>         * tree-ssa-loop-ivopts.c (get_shiftadd_cost): Look into
>         unnecessary type conversion for OP1.