From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by sourceware.org (Postfix) with ESMTPS id 3D91C385AC22 for ; Thu, 24 Mar 2022 19:02:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3D91C385AC22 Received: by mail-pl1-x633.google.com with SMTP id x2so5728118plm.7 for ; Thu, 24 Mar 2022 12:02:59 -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; bh=Z+KVOiSmDhNeRyCyrDKskvY+DOIAivwRPXdVRXpbMIg=; b=vji8yDYzaCSJ19rG33/2UoAOQCE4X9MeMlhAEm1pWsscMWRzhNY4ND5KvpnJQ7ckYj MpjzemOc4I6t+tpcha7pegT6ALV/Zhic6jgfaz9bN8y8FXz8tc0lnGuTKlzOVMvDstC+ wrnus6BaJTig4ndS7dVdWAknLSiGeE/6SdXsHhnMeUnWjqJO6KfG7N/jKkoBIyfK8eQb 8cWPrOpYYqSwfiiN5pB1UX5XEhimPGuOH8wxnEwYkXTJjqX5IO+Iy5nESMpknf7/1z5G pDzS5MiWV7Tx3XTHCA/VCe6BW8PgSXDLNu3pVRrj2B9Q0oZMsNp2OBDijb45bmE3rAYp v7JA== X-Gm-Message-State: AOAM532GioQHt9w8p3LSnN/aOdBH4mNOicEqtNJAiJfIydVmLSNHGSZB jht0N+W8b9oQrCnwLAJQndojTcTZXw0p8p186lY= X-Google-Smtp-Source: ABdhPJz/MsbcX9/us6/EsA4aYka09b857sjYu3UHiVLe7L2qUu3v1C2FM+36L/NPmL3ey5nQjZF0vPQIYLHNZSptFaw= X-Received: by 2002:a17:90a:db50:b0:1c6:99dd:c40d with SMTP id u16-20020a17090adb5000b001c699ddc40dmr19866292pjx.143.1648148578107; Thu, 24 Mar 2022 12:02:58 -0700 (PDT) MIME-Version: 1.0 References: <20220323215734.3927131-1-goldstein.w.n@gmail.com> <20220323215734.3927131-18-goldstein.w.n@gmail.com> In-Reply-To: <20220323215734.3927131-18-goldstein.w.n@gmail.com> From: "H.J. Lu" Date: Thu, 24 Mar 2022 12:02:22 -0700 Message-ID: Subject: Re: [PATCH v1 18/23] x86: Optimize str{n}casecmp TOLOWER logic in strcmp-sse42.S To: Noah Goldstein Cc: GNU C Library , "Carlos O'Donell" Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3026.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Mar 2022 19:03:01 -0000 On Wed, Mar 23, 2022 at 3:02 PM Noah Goldstein wrote: > > Slightly faster method of doing TOLOWER that saves an > instruction. > > Also replace the hard coded 5-byte no with .p2align 4. On builds with > CET enabled this misaligned entry to strcasecmp. > > geometric_mean(N=40) of all benchmarks New / Original: .920 > > All string/memory tests pass. > --- > Geomtric Mean N=40 runs; All functions page aligned > length, align1, align2, max_char, New Time / Old Time > 1, 1, 1, 127, 0.914 > 2, 2, 2, 127, 0.952 > 3, 3, 3, 127, 0.924 > 4, 4, 4, 127, 0.995 > 5, 5, 5, 127, 0.985 > 6, 6, 6, 127, 1.017 > 7, 7, 7, 127, 1.031 > 8, 0, 0, 127, 0.967 > 9, 1, 1, 127, 0.969 > 10, 2, 2, 127, 0.951 > 11, 3, 3, 127, 0.938 > 12, 4, 4, 127, 0.937 > 13, 5, 5, 127, 0.967 > 14, 6, 6, 127, 0.941 > 15, 7, 7, 127, 0.951 > 4, 0, 0, 127, 0.959 > 4, 0, 0, 254, 0.98 > 8, 0, 0, 254, 0.959 > 16, 0, 0, 127, 0.895 > 16, 0, 0, 254, 0.901 > 32, 0, 0, 127, 0.85 > 32, 0, 0, 254, 0.851 > 64, 0, 0, 127, 0.897 > 64, 0, 0, 254, 0.895 > 128, 0, 0, 127, 0.944 > 128, 0, 0, 254, 0.935 > 256, 0, 0, 127, 0.922 > 256, 0, 0, 254, 0.913 > 512, 0, 0, 127, 0.921 > 512, 0, 0, 254, 0.914 > 1024, 0, 0, 127, 0.845 > 1024, 0, 0, 254, 0.84 > 16, 1, 2, 127, 0.923 > 16, 2, 1, 254, 0.955 > 32, 2, 4, 127, 0.979 > 32, 4, 2, 254, 0.957 > 64, 3, 6, 127, 0.866 > 64, 6, 3, 254, 0.849 > 128, 4, 0, 127, 0.882 > 128, 0, 4, 254, 0.876 > 256, 5, 2, 127, 0.877 > 256, 2, 5, 254, 0.882 > 512, 6, 4, 127, 0.822 > 512, 4, 6, 254, 0.862 > 1024, 7, 6, 127, 0.903 > 1024, 6, 7, 254, 0.908 > > sysdeps/x86_64/multiarch/strcmp-sse42.S | 83 +++++++++++-------------- > 1 file changed, 35 insertions(+), 48 deletions(-) > > diff --git a/sysdeps/x86_64/multiarch/strcmp-sse42.S b/sysdeps/x86_64/multiarch/strcmp-sse42.S > index 580feb90e9..7805ae9d41 100644 > --- a/sysdeps/x86_64/multiarch/strcmp-sse42.S > +++ b/sysdeps/x86_64/multiarch/strcmp-sse42.S > @@ -88,9 +88,8 @@ ENTRY (GLABEL(__strcasecmp)) > movq __libc_tsd_LOCALE@gottpoff(%rip),%rax > mov %fs:(%rax),%RDX_LP > > - // XXX 5 byte should be before the function > - /* 5-byte NOP. */ > - .byte 0x0f,0x1f,0x44,0x00,0x00 > + /* Either 1 or 5 bytes (dependeing if CET is enabled). */ > + .p2align 4 > END (GLABEL(__strcasecmp)) > /* FALLTHROUGH to strcasecmp_l. */ > #endif > @@ -99,9 +98,8 @@ ENTRY (GLABEL(__strncasecmp)) > movq __libc_tsd_LOCALE@gottpoff(%rip),%rax > mov %fs:(%rax),%RCX_LP > > - // XXX 5 byte should be before the function > - /* 5-byte NOP. */ > - .byte 0x0f,0x1f,0x44,0x00,0x00 > + /* Either 1 or 5 bytes (dependeing if CET is enabled). */ > + .p2align 4 > END (GLABEL(__strncasecmp)) > /* FALLTHROUGH to strncasecmp_l. */ > #endif > @@ -169,27 +167,22 @@ STRCMP_SSE42: > #if defined USE_AS_STRCASECMP_L || defined USE_AS_STRNCASECMP_L > .section .rodata.cst16,"aM",@progbits,16 > .align 16 > -LABEL(belowupper): > - .quad 0x4040404040404040 > - .quad 0x4040404040404040 > -LABEL(topupper): > -# ifdef USE_AVX > - .quad 0x5a5a5a5a5a5a5a5a > - .quad 0x5a5a5a5a5a5a5a5a > -# else > - .quad 0x5b5b5b5b5b5b5b5b > - .quad 0x5b5b5b5b5b5b5b5b > -# endif > -LABEL(touppermask): > +LABEL(lcase_min): > + .quad 0x3f3f3f3f3f3f3f3f > + .quad 0x3f3f3f3f3f3f3f3f > +LABEL(lcase_max): > + .quad 0x9999999999999999 > + .quad 0x9999999999999999 > +LABEL(case_add): > .quad 0x2020202020202020 > .quad 0x2020202020202020 > .previous > - movdqa LABEL(belowupper)(%rip), %xmm4 > -# define UCLOW_reg %xmm4 > - movdqa LABEL(topupper)(%rip), %xmm5 > -# define UCHIGH_reg %xmm5 > - movdqa LABEL(touppermask)(%rip), %xmm6 > -# define LCQWORD_reg %xmm6 > + movdqa LABEL(lcase_min)(%rip), %xmm4 > +# define LCASE_MIN_reg %xmm4 > + movdqa LABEL(lcase_max)(%rip), %xmm5 > +# define LCASE_MAX_reg %xmm5 > + movdqa LABEL(case_add)(%rip), %xmm6 > +# define CASE_ADD_reg %xmm6 > #endif > cmp $0x30, %ecx > ja LABEL(crosscache)/* rsi: 16-byte load will cross cache line */ > @@ -200,32 +193,26 @@ LABEL(touppermask): > #if defined USE_AS_STRCASECMP_L || defined USE_AS_STRNCASECMP_L > # ifdef USE_AVX > # define TOLOWER(reg1, reg2) \ > - vpcmpgtb UCLOW_reg, reg1, %xmm7; \ > - vpcmpgtb UCHIGH_reg, reg1, %xmm8; \ > - vpcmpgtb UCLOW_reg, reg2, %xmm9; \ > - vpcmpgtb UCHIGH_reg, reg2, %xmm10; \ > - vpandn %xmm7, %xmm8, %xmm8; \ > - vpandn %xmm9, %xmm10, %xmm10; \ > - vpand LCQWORD_reg, %xmm8, %xmm8; \ > - vpand LCQWORD_reg, %xmm10, %xmm10; \ > - vpor reg1, %xmm8, reg1; \ > - vpor reg2, %xmm10, reg2 > + vpaddb LCASE_MIN_reg, reg1, %xmm7; \ > + vpaddb LCASE_MIN_reg, reg2, %xmm8; \ > + vpcmpgtb LCASE_MAX_reg, %xmm7, %xmm7; \ > + vpcmpgtb LCASE_MAX_reg, %xmm8, %xmm8; \ > + vpandn CASE_ADD_reg, %xmm7, %xmm7; \ > + vpandn CASE_ADD_reg, %xmm8, %xmm8; \ > + vpaddb %xmm7, reg1, reg1; \ > + vpaddb %xmm8, reg2, reg2 > # else > # define TOLOWER(reg1, reg2) \ > - movdqa reg1, %xmm7; \ > - movdqa UCHIGH_reg, %xmm8; \ > - movdqa reg2, %xmm9; \ > - movdqa UCHIGH_reg, %xmm10; \ > - pcmpgtb UCLOW_reg, %xmm7; \ > - pcmpgtb reg1, %xmm8; \ > - pcmpgtb UCLOW_reg, %xmm9; \ > - pcmpgtb reg2, %xmm10; \ > - pand %xmm8, %xmm7; \ > - pand %xmm10, %xmm9; \ > - pand LCQWORD_reg, %xmm7; \ > - pand LCQWORD_reg, %xmm9; \ > - por %xmm7, reg1; \ > - por %xmm9, reg2 > + movdqa LCASE_MIN_reg, %xmm7; \ > + movdqa LCASE_MIN_reg, %xmm8; \ > + paddb reg1, %xmm7; \ > + paddb reg2, %xmm8; \ > + pcmpgtb LCASE_MAX_reg, %xmm7; \ > + pcmpgtb LCASE_MAX_reg, %xmm8; \ > + pandn CASE_ADD_reg, %xmm7; \ > + pandn CASE_ADD_reg, %xmm8; \ > + paddb %xmm7, reg1; \ > + paddb %xmm8, reg2 > # endif > TOLOWER (%xmm1, %xmm2) > #else > -- > 2.25.1 > LGTM. Reviewed-by: H.J. Lu Thanks. -- H.J.