From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <richard.guenther@gmail.com>
Received: from mail-qv1-xf36.google.com (mail-qv1-xf36.google.com
 [IPv6:2607:f8b0:4864:20::f36])
 by sourceware.org (Postfix) with ESMTPS id E571E3841469
 for <gcc-patches@gcc.gnu.org>; Tue, 21 Jun 2022 07:33:42 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E571E3841469
Received: by mail-qv1-xf36.google.com with SMTP id o43so19151044qvo.4
 for <gcc-patches@gcc.gnu.org>; Tue, 21 Jun 2022 00:33:42 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20210112;
 h=x-gm-message-state:mime-version:references:in-reply-to:from:date
 :message-id:subject:to:cc:content-transfer-encoding;
 bh=VW58Fbu6UCJq964v08FWKgXxBU1zaIJ6DL/73Ep4y2Y=;
 b=oaS2T7/0jK2h7ey2QEUCWTbs8D+b2X1nxvLnCXGU+9HzBMRVvZiAeHfyEr6J7c2lcw
 BNshk826sTxIsPs/03XnmBiqY1UmkHXPLlz959LcuRzFsVDVQVw/RtSGqdpTcXhUHemb
 NlcJl9Y3SomSen9Gjsdl4gfm4bVcPzoX0oCKlBG6YldwOk5A+7v3M2JCb5HTgG88/6Y7
 ZLa9FKoXDRHe+1ixzRFQRUEjwt19HqLv9B4lkPluzNdzzMoajbvQTwu4iQvo5TglGDse
 4JpS+2QS7pLqMX4voXNK+8OTAVNHxbkyyrB+j75LCHL9zcvabhnyxy8TiRuNrfIGBAnV
 HIfQ==
X-Gm-Message-State: AJIora8sAnWJEbsPikZMmkvEmnKvQzS8pUWmYmS9Vt+a0q35LUHuD5X2
 lDT6aVp4T397FtooqZwCPfFFdqTbvlHrmfFbjV0=
X-Google-Smtp-Source: AGRyM1unQqCgSKwpqjoPxC/WQBTXurEoxkOa2zUlXuo3JUD48V/8hm93W6NcFVKE9UQkWIOQqRDs2Cr73QKXcTV+CQc=
X-Received: by 2002:a05:6214:238d:b0:46e:6864:ac18 with SMTP id
 fw13-20020a056214238d00b0046e6864ac18mr21522600qvb.78.1655796822300; Tue, 21
 Jun 2022 00:33:42 -0700 (PDT)
MIME-Version: 1.0
References: <tencent_5B86F0F91457C4BE38ACDDAA@qq.com>
In-Reply-To: <tencent_5B86F0F91457C4BE38ACDDAA@qq.com>
From: Richard Biener <richard.guenther@gmail.com>
Date: Tue, 21 Jun 2022 09:33:31 +0200
Message-ID: <CAFiYyc0zP4y8Mq7UkS_KJkfa3JJWA_ALt30ySePQKA7k2nJkxA@mail.gmail.com>
Subject: Re: [PATCH] if-to-switch: Don't skip the first condition bb when
 find_conditions in if-to-switch [PR105740]
To: =?UTF-8?B?eGlvbmdodWx1byjnvZfpm4TomY4p?= <xionghuluo@tencent.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Spam-Status: No, score=-0.1 required=5.0 tests=BAYES_00, BODY_8BITS,
 DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM,
 RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP,
 T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
 server2.sourceware.org
X-BeenThere: gcc-patches@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-patches mailing list <gcc-patches.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-patches/>
List-Post: <mailto:gcc-patches@gcc.gnu.org>
List-Help: <mailto:gcc-patches-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Tue, 21 Jun 2022 07:33:49 -0000

On Tue, Jun 21, 2022 at 5:06 AM xionghuluo(=E7=BD=97=E9=9B=84=E8=99=8E) via=
 Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Current GCC generates:
>
>
> &nbsp;test2:
> .LFB0:
> &nbsp; &nbsp; &nbsp; &nbsp; .cfi_startproc
> &nbsp; &nbsp; &nbsp; &nbsp; xorl &nbsp; &nbsp;%edx, %edx
> &nbsp; &nbsp; &nbsp; &nbsp; cmpl &nbsp; &nbsp;$3, (%rdi)
> &nbsp; &nbsp; &nbsp; &nbsp; jle &nbsp; &nbsp; .L1
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;16(%rdi), %eax
> &nbsp; &nbsp; &nbsp; &nbsp; cmpl &nbsp; &nbsp;$1, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; je &nbsp; &nbsp; &nbsp;.L4
> &nbsp; &nbsp; &nbsp; &nbsp; subl &nbsp; &nbsp;$2, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; cmpl &nbsp; &nbsp;$4, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; ja &nbsp; &nbsp; &nbsp;.L1
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;CSWTCH.1(,%rax,4), %edx
> .L1:
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;%edx, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; ret
> &nbsp; &nbsp; &nbsp; &nbsp; .p2align 4,,10
> &nbsp; &nbsp; &nbsp; &nbsp; .p2align 3
> .L4:
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;$12, %edx
> &nbsp; &nbsp; &nbsp; &nbsp; jmp &nbsp; &nbsp; .L1
> &nbsp; &nbsp; &nbsp; &nbsp; .cfi_endproc
> .LFE0:
> &nbsp; &nbsp; &nbsp; &nbsp; .size &nbsp; test2, .-test2
> &nbsp; &nbsp; &nbsp; &nbsp; .section &nbsp; &nbsp; &nbsp; &nbsp;.rodata
> &nbsp; &nbsp; &nbsp; &nbsp; .align 16
> &nbsp; &nbsp; &nbsp; &nbsp; .type &nbsp; CSWTCH.1, @object
> &nbsp; &nbsp; &nbsp; &nbsp; .size &nbsp; CSWTCH.1, 20
> CSWTCH.1:
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 27
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 38
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 18
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 58
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 68
>
>
>
>
> With the patch attatched:
>
>
> &nbsp;test2:
> .LFB0:
> &nbsp; &nbsp; &nbsp; &nbsp; .cfi_startproc
> &nbsp; &nbsp; &nbsp; &nbsp; xorl &nbsp; &nbsp;%edx, %edx
> &nbsp; &nbsp; &nbsp; &nbsp; cmpl &nbsp; &nbsp;$3, (%rdi)
> &nbsp; &nbsp; &nbsp; &nbsp; jle &nbsp; &nbsp; .L1
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;16(%rdi), %eax
> &nbsp; &nbsp; &nbsp; &nbsp; subl &nbsp; &nbsp;$1, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; cmpl &nbsp; &nbsp;$5, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; jbe &nbsp; &nbsp; .L6
> .L1:
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;%edx, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; ret
> &nbsp; &nbsp; &nbsp; &nbsp; .p2align 4,,10
> &nbsp; &nbsp; &nbsp; &nbsp; .p2align 3
> .L6:
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;CSWTCH.1(,%rax,4), %edx
> &nbsp; &nbsp; &nbsp; &nbsp; movl &nbsp; &nbsp;%edx, %eax
> &nbsp; &nbsp; &nbsp; &nbsp; ret
> &nbsp; &nbsp; &nbsp; &nbsp; .cfi_endproc
> .LFE0:
> &nbsp; &nbsp; &nbsp; &nbsp; .size &nbsp; test2, .-test2
> &nbsp; &nbsp; &nbsp; &nbsp; .section &nbsp; &nbsp; &nbsp; &nbsp;.rodata
> &nbsp; &nbsp; &nbsp; &nbsp; .align 16
> &nbsp; &nbsp; &nbsp; &nbsp; .type &nbsp; CSWTCH.1, @object
> &nbsp; &nbsp; &nbsp; &nbsp; .size &nbsp; CSWTCH.1, 24
> CSWTCH.1:
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 12
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 27
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 38
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 18
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 58
> &nbsp; &nbsp; &nbsp; &nbsp; .long &nbsp; 68
>
>
> Bootstrap and regression tested pass on x86_64-linux-gnu, OK for master?

OK if you add a comment that an empty conditions_in_bbs indicates we are
processing the first basic-block (that's not obvious to me).

Thanks,
Richard.