From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by sourceware.org (Postfix) with ESMTPS id 97C043858016 for ; Tue, 15 Feb 2022 16:51:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 97C043858016 Received: by mail-pj1-x102d.google.com with SMTP id d9-20020a17090a498900b001b8bb1d00e7so2629428pjh.3 for ; Tue, 15 Feb 2022 08:51:25 -0800 (PST) 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=dBrEuCg72Uil4FiAqrLyZjVS8G8u/ICC1fZqXnuPrUo=; b=05l0HKrCfKSdQwR9bS1sOfOouvNsjTVOQn6ggEoGBZ+ZmTuMvo1Twtr2VJc3uPU3Kc UtOZ+VL9i7REvHBILydRLSHG5xuGmi/q9/MushvGwBj5aJTyuCWsSpOwM8KKTjv21eyn nsvjHcrnFxKhb/5aS8AwMD+sfLiHCiNIzUSWrqebwu2DnusXcD1lckWuM5+oIlK7jdVB JbxnXEYKBdT+RzsynwxP9YeGR+KQnHugMqTt+SetxF7esj1MLyGyLo8U0xf8iWcOyClx dQ+rgS1rFfk7NRc6eCd+ZOET5K5Kecpsmy9XrLPJmXNC/0f7xVZxByUgmnB2w4gSn9J7 V+Yw== X-Gm-Message-State: AOAM531jG+8XibIWmvguCi7yqa6OHGuOcaMuDQCOsjXEO+vkTKpHLsdK E64ZmVK5zxOJ/w13mA6/zs+TuBTnss1r7cNnnqs= X-Google-Smtp-Source: ABdhPJzF0shZKqN3rGvEZUhTFf/gT2h1086qDV+XrTgvE+14nVOV4zwRCn6iCj3PYzx5DBjarG5/OmC816Lx/RuyGxw= X-Received: by 2002:a17:902:d48b:: with SMTP id c11mr4852316plg.109.1644943884727; Tue, 15 Feb 2022 08:51:24 -0800 (PST) MIME-Version: 1.0 References: <20220215162751.281955-1-goldstein.w.n@gmail.com> In-Reply-To: From: Noah Goldstein Date: Tue, 15 Feb 2022 10:51:14 -0600 Message-ID: Subject: Re: [PATCH v1] x86: Fallback {str|wcs}cmp RTM in the ncmp overflow case [BZ #28896] To: "H.J. Lu" Cc: GNU C Library , "Carlos O'Donell" Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=0.5 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, UNWANTED_LANGUAGE_BODY 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: Tue, 15 Feb 2022 16:51:27 -0000 On Tue, Feb 15, 2022 at 10:30 AM H.J. Lu wrote: > > On Tue, Feb 15, 2022 at 8:28 AM Noah Goldstein wrote: > > > > In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would > > call strcmp-avx2 and wcsncmp-avx2 respectively. This would have > > not checks around vzeroupper and would trigger spurious > > aborts. This commit fixes that. > > Include a testcase? Added test case in V2. Don't have the hardware to check it though, can you? > > > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all > > pass. Note not tested on a machine that supports RTM (non > > available). > > --- > > sysdeps/x86_64/multiarch/strcmp-avx2.S | 8 ++------ > > sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S | 1 + > > sysdeps/x86_64/multiarch/strncmp-avx2.S | 1 + > > sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S | 2 +- > > sysdeps/x86_64/multiarch/wcsncmp-avx2.S | 2 +- > > 5 files changed, 6 insertions(+), 8 deletions(-) > > > > diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S > > index 07a5a2c889..52ff5ad724 100644 > > --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S > > +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S > > @@ -193,10 +193,10 @@ L(ret_zero): > > .p2align 4,, 5 > > L(one_or_less): > > jb L(ret_zero) > > -# ifdef USE_AS_WCSCMP > > /* 'nbe' covers the case where length is negative (large > > unsigned). */ > > - jnbe __wcscmp_avx2 > > + jnbe OVERFLOW_STRCMP > > +# ifdef USE_AS_WCSCMP > > movl (%rdi), %edx > > xorl %eax, %eax > > cmpl (%rsi), %edx > > @@ -205,10 +205,6 @@ L(one_or_less): > > negl %eax > > orl $1, %eax > > # else > > - /* 'nbe' covers the case where length is negative (large > > - unsigned). */ > > - > > - jnbe __strcmp_avx2 > > movzbl (%rdi), %eax > > movzbl (%rsi), %ecx > > subl %ecx, %eax > > diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S > > index 37d1224bb9..68bad365ba 100644 > > --- a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S > > +++ b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S > > @@ -1,3 +1,4 @@ > > #define STRCMP __strncmp_avx2_rtm > > #define USE_AS_STRNCMP 1 > > +#define OVERFLOW_STRCMP __strcmp_avx2_rtm > > #include "strcmp-avx2-rtm.S" > > diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2.S b/sysdeps/x86_64/multiarch/strncmp-avx2.S > > index 1678bcc235..f138e9f1fd 100644 > > --- a/sysdeps/x86_64/multiarch/strncmp-avx2.S > > +++ b/sysdeps/x86_64/multiarch/strncmp-avx2.S > > @@ -1,3 +1,4 @@ > > #define STRCMP __strncmp_avx2 > > #define USE_AS_STRNCMP 1 > > +#define OVERFLOW_STRCMP __strcmp_avx2 > > #include "strcmp-avx2.S" > > diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S > > index 4e88c70cc6..f467582cbe 100644 > > --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S > > +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S > > @@ -1,5 +1,5 @@ > > #define STRCMP __wcsncmp_avx2_rtm > > #define USE_AS_STRNCMP 1 > > #define USE_AS_WCSCMP 1 > > - > > +#define OVERFLOW_STRCMP __wcscmp_avx2_rtm > > #include "strcmp-avx2-rtm.S" > > diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S > > index 4fa1de4d3f..e9ede522b8 100644 > > --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S > > +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S > > @@ -1,5 +1,5 @@ > > #define STRCMP __wcsncmp_avx2 > > #define USE_AS_STRNCMP 1 > > #define USE_AS_WCSCMP 1 > > - > > +#define OVERFLOW_STRCMP __wcscmp_avx2 > > #include "strcmp-avx2.S" > > -- > > 2.25.1 > > > > > -- > H.J.