From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-patches-return-381780-listarch-gcc-patches=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 10153 invoked by alias); 24 Oct 2014 13:58:52 -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 10142 invoked by uid 89); 24 Oct 2014 13:58:51 -0000
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2
X-HELO: mail-yh0-f47.google.com
Received: from mail-yh0-f47.google.com (HELO mail-yh0-f47.google.com) (209.85.213.47) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Fri, 24 Oct 2014 13:58:50 +0000
Received: by mail-yh0-f47.google.com with SMTP id c41so799913yho.34        for <gcc-patches@gcc.gnu.org>; Fri, 24 Oct 2014 06:58:48 -0700 (PDT)
X-Received: by 10.236.231.225 with SMTP id l91mr5096016yhq.166.1414159128221; Fri, 24 Oct 2014 06:58:48 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.170.38.12 with HTTP; Fri, 24 Oct 2014 06:58:27 -0700 (PDT)
In-Reply-To: <544A2BEE.4030106@gjlay.de>
References: <5449071E.8040909@gjlay.de> <CADOs=zZz_nenyWBr9_9UcqLh7pWadTCkMtY73b66OqAWVokshg@mail.gmail.com> <544A2BEE.4030106@gjlay.de>
From: Denis Chertykov <chertykov@gmail.com>
Date: Fri, 24 Oct 2014 14:03:00 -0000
Message-ID: <CADOs=zaR+5mUdooWCYftvkKO42HPNZ=SCQMqRusd4T3R8H9+cw@mail.gmail.com>
Subject: Re: [patch,avr] tweak sign extensions, take #2
To: Georg-Johann Lay <avr@gjlay.de>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Content-Type: text/plain; charset=UTF-8
X-SW-Source: 2014-10/txt/msg02555.txt.bz2

2014-10-24 14:37 GMT+04:00 Georg-Johann Lay <avr@gjlay.de>:
> Am 10/23/2014 08:16 PM schrieb Denis Chertykov:
>>>
>>> This optimization makes most sign-extensions one instruction shorter in
>>> the
>>> case when the source register may be clobbered and the register numbers
>>> are
>>> different.  Source and destination may overlap.
>>>
>>> Ok for trunk?
>>>
>>> Johann
>>>
>>> gcc/
>>>          * config/avr/avr.md (extendqihi2, extendqipsi2, extendqisi2)
>>>          (extendhipsi2, extendhisi2): Optimize if source reg is unused
>>>          after the insns and has different REGNO than destination.
>>
>>
>> Approved.
>>
>> Denis.
>
>
> Finally I switched to a solution that avoids all the ugly asm snippets and
> special casing, and which is exact w.r.t code size.  So allow me drop the
> patch from above and to propose this one for trunk.  Sorry for the
> inconvenience.
>
> In any case it uses LSL/SBC idiom instead of the old CLR/SBRC/COM.
>
>
> Johann
>
>         * avr-protos.h (avr_out_sign_extend): New.
>         * avr.c (avr_adjust_insn_length) [ADJUST_LEN_SEXT]: Handle.
>         (avr_out_sign_extend): New function.
>         * avr.md (extendqihi2, extendqipsi2, extendqisi2, extendhipsi2)
>         (extendhisi2, extendpsisi2): Use it.
>         (adjust_len) [sext]: New.
>
>
>

I'm agree with you. It's better.
Approved.

Denis.