From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vs1-xe34.google.com (mail-vs1-xe34.google.com [IPv6:2607:f8b0:4864:20::e34]) by sourceware.org (Postfix) with ESMTPS id 5FC243953804; Thu, 12 May 2022 20:13:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 5FC243953804 Received: by mail-vs1-xe34.google.com with SMTP id t85so6378414vst.4; Thu, 12 May 2022 13:13:57 -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=b0z/c7L2zoxwq4tRqKkMwv464sI7GlCjraQMWREk+qQ=; b=Eh1LOrbB9mCINBPIwVsdEwwsCREVN4Szs2qQqGV7SRf429AM1u45LyuUKQ25/L3/oB U0MBff1//DH43cqxQmyOg1XsyYk2AklY6VBYaDj6UmxF1JX0a3yAuLzeCG6mSJpI+Ipq ahMDAOSmJFXe6J2Q0ir7KyWp79eYFLSbGZ57xHJkUarNYHZNugexOsCLvgrNIdEdPXnE 10CZLTgcuIjLpYpjhR/BPURC9+uptX9rSEsgfeGmAB1prL8hF2I5wYTWCQieuGyawCA4 cHUOK/xj3+HV7YVe3FvoGEtwmlTmEqfTH6MOoYmNfX/ZdvshKm6i6B4GBMlitBA/kB0o OYUQ== X-Gm-Message-State: AOAM532rp2Z+gy2rhmXl+kDXcU/ejFvdHIkNA0BWvYDVH9X4SCQz5pQw BtmegK7qmC7bNWQyVOexElsLp1HOPVFYBNskQmWOnCp1wgk= X-Google-Smtp-Source: ABdhPJwTCAyr8m0HScCXO0DeUGBJZoClg0P+nXGC2MG10+f4Xd/XDtLjDS0MgFFgTdFThB7OIbF6881zjIiiCNjIsnw= X-Received: by 2002:a67:ee4f:0:b0:32c:ee75:6e98 with SMTP id g15-20020a67ee4f000000b0032cee756e98mr914357vsp.79.1652386436687; Thu, 12 May 2022 13:13:56 -0700 (PDT) MIME-Version: 1.0 References: <20220421031410.2142238-1-goldstein.w.n@gmail.com> <20220422015230.3241772-1-goldstein.w.n@gmail.com> <20220422015230.3241772-2-goldstein.w.n@gmail.com> In-Reply-To: From: Sunil Pandey Date: Thu, 12 May 2022 13:13:20 -0700 Message-ID: Subject: Re: [PATCH v3 2/4] x86: Optimize {str|wcs}rchr-sse2 To: "H.J. Lu" , Libc-stable Mailing List Cc: Noah Goldstein , GNU C Library Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, GIT_PATCH_0, HK_RANDOM_ENVFROM, HK_RANDOM_FROM, KAM_NUMSUBJECT, KAM_SHORT, 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: libc-stable@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-stable mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 May 2022 20:14:00 -0000 On Fri, Apr 22, 2022 at 12:09 PM H.J. Lu via Libc-alpha wrote: > > On Thu, Apr 21, 2022 at 6:52 PM Noah Goldstein wrote: > > > > The new code unrolls the main loop slightly without adding too much > > overhead and minimizes the comparisons for the search CHAR. > > > > Geometric Mean of all benchmarks New / Old: 0.741 > > See email for all results. > > > > Full xcheck passes on x86_64 with and without multiarch enabled. > > --- > > sysdeps/x86_64/multiarch/strrchr-sse2.S | 2 +- > > sysdeps/x86_64/multiarch/wcsrchr-sse2.S | 3 +- > > sysdeps/x86_64/strrchr.S | 510 +++++++++++++++--------- > > sysdeps/x86_64/wcsrchr.S | 268 +------------ > > 4 files changed, 339 insertions(+), 444 deletions(-) > > > > diff --git a/sysdeps/x86_64/multiarch/strrchr-sse2.S b/sysdeps/x86_64/multiarch/strrchr-sse2.S > > index db1b44c23c..866396e947 100644 > > --- a/sysdeps/x86_64/multiarch/strrchr-sse2.S > > +++ b/sysdeps/x86_64/multiarch/strrchr-sse2.S > > @@ -17,7 +17,7 @@ > > . */ > > > > #if IS_IN (libc) > > -# define strrchr __strrchr_sse2 > > +# define STRRCHR __strrchr_sse2 > > > > # undef weak_alias > > # define weak_alias(strrchr, rindex) > > diff --git a/sysdeps/x86_64/multiarch/wcsrchr-sse2.S b/sysdeps/x86_64/multiarch/wcsrchr-sse2.S > > index 78d1ca6553..69d2f3cdb1 100644 > > --- a/sysdeps/x86_64/multiarch/wcsrchr-sse2.S > > +++ b/sysdeps/x86_64/multiarch/wcsrchr-sse2.S > > @@ -17,7 +17,6 @@ > > . */ > > > > #if IS_IN (libc) > > -# define wcsrchr __wcsrchr_sse2 > > +# define STRRCHR __wcsrchr_sse2 > > #endif > > - > > #include "../wcsrchr.S" > > diff --git a/sysdeps/x86_64/strrchr.S b/sysdeps/x86_64/strrchr.S > > index 50d886713e..4d7ba4ceb2 100644 > > --- a/sysdeps/x86_64/strrchr.S > > +++ b/sysdeps/x86_64/strrchr.S > > @@ -19,210 +19,360 @@ > > > > #include > > > > +#ifndef STRRCHR > > +# define STRRCHR strrchr > > +#endif > > + > > +#ifdef USE_AS_WCSRCHR > > +# define PCMPEQ pcmpeqd > > +# define CHAR_SIZE 4 > > +# define PMINU pminud > > +#else > > +# define PCMPEQ pcmpeqb > > +# define CHAR_SIZE 1 > > +# define PMINU pminub > > +#endif > > + > > +#define PAGE_SIZE 4096 > > +#define VEC_SIZE 16 > > + > > .text > > -ENTRY (strrchr) > > - movd %esi, %xmm1 > > +ENTRY(STRRCHR) > > + movd %esi, %xmm0 > > movq %rdi, %rax > > - andl $4095, %eax > > - punpcklbw %xmm1, %xmm1 > > - cmpq $4032, %rax > > - punpcklwd %xmm1, %xmm1 > > - pshufd $0, %xmm1, %xmm1 > > + andl $(PAGE_SIZE - 1), %eax > > +#ifndef USE_AS_WCSRCHR > > + punpcklbw %xmm0, %xmm0 > > + punpcklwd %xmm0, %xmm0 > > +#endif > > + pshufd $0, %xmm0, %xmm0 > > + cmpl $(PAGE_SIZE - VEC_SIZE), %eax > > ja L(cross_page) > > - movdqu (%rdi), %xmm0 > > + > > +L(cross_page_continue): > > + movups (%rdi), %xmm1 > > pxor %xmm2, %xmm2 > > - movdqa %xmm0, %xmm3 > > - pcmpeqb %xmm1, %xmm0 > > - pcmpeqb %xmm2, %xmm3 > > - pmovmskb %xmm0, %ecx > > - pmovmskb %xmm3, %edx > > - testq %rdx, %rdx > > - je L(next_48_bytes) > > - leaq -1(%rdx), %rax > > - xorq %rdx, %rax > > - andq %rcx, %rax > > - je L(exit) > > - bsrq %rax, %rax > > + PCMPEQ %xmm1, %xmm2 > > + pmovmskb %xmm2, %ecx > > + testl %ecx, %ecx > > + jz L(aligned_more) > > + > > + PCMPEQ %xmm0, %xmm1 > > + pmovmskb %xmm1, %eax > > + leal -1(%rcx), %edx > > + xorl %edx, %ecx > > + andl %ecx, %eax > > + jz L(ret0) > > + bsrl %eax, %eax > > addq %rdi, %rax > > + /* We are off by 3 for wcsrchr if search CHAR is non-zero. If > > + search CHAR is zero we are correct. Either way `andq > > + -CHAR_SIZE, %rax` gets the correct result. */ > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > +L(ret0): > > ret > > > > + /* Returns for first vec x1/x2 have hard coded backward search > > + path for earlier matches. */ > > .p2align 4 > > -L(next_48_bytes): > > - movdqu 16(%rdi), %xmm4 > > - movdqa %xmm4, %xmm5 > > - movdqu 32(%rdi), %xmm3 > > - pcmpeqb %xmm1, %xmm4 > > - pcmpeqb %xmm2, %xmm5 > > - movdqu 48(%rdi), %xmm0 > > - pmovmskb %xmm5, %edx > > - movdqa %xmm3, %xmm5 > > - pcmpeqb %xmm1, %xmm3 > > - pcmpeqb %xmm2, %xmm5 > > - pcmpeqb %xmm0, %xmm2 > > - salq $16, %rdx > > - pmovmskb %xmm3, %r8d > > - pmovmskb %xmm5, %eax > > - pmovmskb %xmm2, %esi > > - salq $32, %r8 > > - salq $32, %rax > > - pcmpeqb %xmm1, %xmm0 > > - orq %rdx, %rax > > - movq %rsi, %rdx > > - pmovmskb %xmm4, %esi > > - salq $48, %rdx > > - salq $16, %rsi > > - orq %r8, %rsi > > - orq %rcx, %rsi > > - pmovmskb %xmm0, %ecx > > - salq $48, %rcx > > - orq %rcx, %rsi > > - orq %rdx, %rax > > - je L(loop_header2) > > - leaq -1(%rax), %rcx > > - xorq %rax, %rcx > > - andq %rcx, %rsi > > - je L(exit) > > - bsrq %rsi, %rsi > > - leaq (%rdi,%rsi), %rax > > +L(first_vec_x0_test): > > + PCMPEQ %xmm0, %xmm1 > > + pmovmskb %xmm1, %eax > > + testl %eax, %eax > > + jz L(ret0) > > + bsrl %eax, %eax > > + addq %r8, %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > ret > > > > .p2align 4 > > -L(loop_header2): > > - testq %rsi, %rsi > > - movq %rdi, %rcx > > - je L(no_c_found) > > -L(loop_header): > > - addq $64, %rdi > > - pxor %xmm7, %xmm7 > > - andq $-64, %rdi > > - jmp L(loop_entry) > > +L(first_vec_x1): > > + PCMPEQ %xmm0, %xmm2 > > + pmovmskb %xmm2, %eax > > + leal -1(%rcx), %edx > > + xorl %edx, %ecx > > + andl %ecx, %eax > > + jz L(first_vec_x0_test) > > + bsrl %eax, %eax > > + leaq (VEC_SIZE)(%rdi, %rax), %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > + ret > > > > .p2align 4 > > -L(loop64): > > - testq %rdx, %rdx > > - cmovne %rdx, %rsi > > - cmovne %rdi, %rcx > > - addq $64, %rdi > > -L(loop_entry): > > - movdqa 32(%rdi), %xmm3 > > - pxor %xmm6, %xmm6 > > - movdqa 48(%rdi), %xmm2 > > - movdqa %xmm3, %xmm0 > > - movdqa 16(%rdi), %xmm4 > > - pminub %xmm2, %xmm0 > > - movdqa (%rdi), %xmm5 > > - pminub %xmm4, %xmm0 > > - pminub %xmm5, %xmm0 > > - pcmpeqb %xmm7, %xmm0 > > - pmovmskb %xmm0, %eax > > - movdqa %xmm5, %xmm0 > > - pcmpeqb %xmm1, %xmm0 > > - pmovmskb %xmm0, %r9d > > - movdqa %xmm4, %xmm0 > > - pcmpeqb %xmm1, %xmm0 > > - pmovmskb %xmm0, %edx > > - movdqa %xmm3, %xmm0 > > - pcmpeqb %xmm1, %xmm0 > > - salq $16, %rdx > > - pmovmskb %xmm0, %r10d > > - movdqa %xmm2, %xmm0 > > - pcmpeqb %xmm1, %xmm0 > > - salq $32, %r10 > > - orq %r10, %rdx > > - pmovmskb %xmm0, %r8d > > - orq %r9, %rdx > > - salq $48, %r8 > > - orq %r8, %rdx > > +L(first_vec_x1_test): > > + PCMPEQ %xmm0, %xmm2 > > + pmovmskb %xmm2, %eax > > testl %eax, %eax > > - je L(loop64) > > - pcmpeqb %xmm6, %xmm4 > > - pcmpeqb %xmm6, %xmm3 > > - pcmpeqb %xmm6, %xmm5 > > - pmovmskb %xmm4, %eax > > - pmovmskb %xmm3, %r10d > > - pcmpeqb %xmm6, %xmm2 > > - pmovmskb %xmm5, %r9d > > - salq $32, %r10 > > - salq $16, %rax > > - pmovmskb %xmm2, %r8d > > - orq %r10, %rax > > - orq %r9, %rax > > - salq $48, %r8 > > - orq %r8, %rax > > - leaq -1(%rax), %r8 > > - xorq %rax, %r8 > > - andq %r8, %rdx > > - cmovne %rdi, %rcx > > - cmovne %rdx, %rsi > > - bsrq %rsi, %rsi > > - leaq (%rcx,%rsi), %rax > > + jz L(first_vec_x0_test) > > + bsrl %eax, %eax > > + leaq (VEC_SIZE)(%rdi, %rax), %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > + ret > > + > > + .p2align 4 > > +L(first_vec_x2): > > + PCMPEQ %xmm0, %xmm3 > > + pmovmskb %xmm3, %eax > > + leal -1(%rcx), %edx > > + xorl %edx, %ecx > > + andl %ecx, %eax > > + jz L(first_vec_x1_test) > > + bsrl %eax, %eax > > + leaq (VEC_SIZE * 2)(%rdi, %rax), %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > + ret > > + > > + .p2align 4 > > +L(aligned_more): > > + /* Save original pointer if match was in VEC 0. */ > > + movq %rdi, %r8 > > + andq $-VEC_SIZE, %rdi > > + > > + movaps VEC_SIZE(%rdi), %xmm2 > > + pxor %xmm3, %xmm3 > > + PCMPEQ %xmm2, %xmm3 > > + pmovmskb %xmm3, %ecx > > + testl %ecx, %ecx > > + jnz L(first_vec_x1) > > + > > + movaps (VEC_SIZE * 2)(%rdi), %xmm3 > > + pxor %xmm4, %xmm4 > > + PCMPEQ %xmm3, %xmm4 > > + pmovmskb %xmm4, %ecx > > + testl %ecx, %ecx > > + jnz L(first_vec_x2) > > + > > + addq $VEC_SIZE, %rdi > > + /* Save pointer again before realigning. */ > > + movq %rdi, %rsi > > + andq $-(VEC_SIZE * 2), %rdi > > + .p2align 4 > > +L(first_loop): > > + /* Do 2x VEC at a time. */ > > + movaps (VEC_SIZE * 2)(%rdi), %xmm4 > > + movaps (VEC_SIZE * 3)(%rdi), %xmm5 > > + /* Since SSE2 no pminud so wcsrchr needs seperate logic for > > + detecting zero. Note if this is found to be a bottleneck it > > + may be worth adding an SSE4.1 wcsrchr implementation. */ > > +#ifdef USE_AS_WCSRCHR > > + movaps %xmm5, %xmm6 > > + pxor %xmm8, %xmm8 > > + > > + PCMPEQ %xmm8, %xmm5 > > + PCMPEQ %xmm4, %xmm8 > > + por %xmm5, %xmm8 > > +#else > > + movaps %xmm5, %xmm6 > > + PMINU %xmm4, %xmm5 > > +#endif > > + > > + movaps %xmm4, %xmm9 > > + PCMPEQ %xmm0, %xmm4 > > + PCMPEQ %xmm0, %xmm6 > > + movaps %xmm6, %xmm7 > > + por %xmm4, %xmm6 > > +#ifndef USE_AS_WCSRCHR > > + pxor %xmm8, %xmm8 > > + PCMPEQ %xmm5, %xmm8 > > +#endif > > + pmovmskb %xmm8, %ecx > > + pmovmskb %xmm6, %eax > > + > > + addq $(VEC_SIZE * 2), %rdi > > + /* Use `addl` 1) so we can undo it with `subl` and 2) it can > > + macro-fuse with `jz`. */ > > + addl %ecx, %eax > > + jz L(first_loop) > > + > > + /* Check if there is zero match. */ > > + testl %ecx, %ecx > > + jz L(second_loop_match) > > + > > + /* Check if there was a match in last iteration. */ > > + subl %ecx, %eax > > + jnz L(new_match) > > + > > +L(first_loop_old_match): > > + PCMPEQ %xmm0, %xmm2 > > + PCMPEQ %xmm0, %xmm3 > > + pmovmskb %xmm2, %ecx > > + pmovmskb %xmm3, %eax > > + addl %eax, %ecx > > + jz L(first_vec_x0_test) > > + /* NB: We could move this shift to before the branch and save a > > + bit of code size / performance on the fall through. The > > + branch leads to the null case which generally seems hotter > > + than char in first 3x VEC. */ > > + sall $16, %eax > > + orl %ecx, %eax > > + > > + bsrl %eax, %eax > > + addq %rsi, %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > + ret > > + > > + .p2align 4 > > +L(new_match): > > + pxor %xmm6, %xmm6 > > + PCMPEQ %xmm9, %xmm6 > > + pmovmskb %xmm6, %eax > > + sall $16, %ecx > > + orl %eax, %ecx > > + > > + /* We can't reuse either of the old comparisons as since we mask > > + of zeros after first zero (instead of using the full > > + comparison) we can't gurantee no interference between match > > + after end of string and valid match. */ > > + pmovmskb %xmm4, %eax > > + pmovmskb %xmm7, %edx > > + sall $16, %edx > > + orl %edx, %eax > > + > > + leal -1(%ecx), %edx > > + xorl %edx, %ecx > > + andl %ecx, %eax > > + jz L(first_loop_old_match) > > + bsrl %eax, %eax > > + addq %rdi, %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > ret > > > > + /* Save minimum state for getting most recent match. We can > > + throw out all previous work. */ > > .p2align 4 > > -L(no_c_found): > > - movl $1, %esi > > - xorl %ecx, %ecx > > - jmp L(loop_header) > > +L(second_loop_match): > > + movq %rdi, %rsi > > + movaps %xmm4, %xmm2 > > + movaps %xmm7, %xmm3 > > > > .p2align 4 > > -L(exit): > > - xorl %eax, %eax > > +L(second_loop): > > + movaps (VEC_SIZE * 2)(%rdi), %xmm4 > > + movaps (VEC_SIZE * 3)(%rdi), %xmm5 > > + /* Since SSE2 no pminud so wcsrchr needs seperate logic for > > + detecting zero. Note if this is found to be a bottleneck it > > + may be worth adding an SSE4.1 wcsrchr implementation. */ > > +#ifdef USE_AS_WCSRCHR > > + movaps %xmm5, %xmm6 > > + pxor %xmm8, %xmm8 > > + > > + PCMPEQ %xmm8, %xmm5 > > + PCMPEQ %xmm4, %xmm8 > > + por %xmm5, %xmm8 > > +#else > > + movaps %xmm5, %xmm6 > > + PMINU %xmm4, %xmm5 > > +#endif > > + > > + movaps %xmm4, %xmm9 > > + PCMPEQ %xmm0, %xmm4 > > + PCMPEQ %xmm0, %xmm6 > > + movaps %xmm6, %xmm7 > > + por %xmm4, %xmm6 > > +#ifndef USE_AS_WCSRCHR > > + pxor %xmm8, %xmm8 > > + PCMPEQ %xmm5, %xmm8 > > +#endif > > + > > + pmovmskb %xmm8, %ecx > > + pmovmskb %xmm6, %eax > > + > > + addq $(VEC_SIZE * 2), %rdi > > + /* Either null term or new occurence of CHAR. */ > > + addl %ecx, %eax > > + jz L(second_loop) > > + > > + /* No null term so much be new occurence of CHAR. */ > > + testl %ecx, %ecx > > + jz L(second_loop_match) > > + > > + > > + subl %ecx, %eax > > + jnz L(second_loop_new_match) > > + > > +L(second_loop_old_match): > > + pmovmskb %xmm2, %ecx > > + pmovmskb %xmm3, %eax > > + sall $16, %eax > > + orl %ecx, %eax > > + bsrl %eax, %eax > > + addq %rsi, %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > ret > > > > .p2align 4 > > +L(second_loop_new_match): > > + pxor %xmm6, %xmm6 > > + PCMPEQ %xmm9, %xmm6 > > + pmovmskb %xmm6, %eax > > + sall $16, %ecx > > + orl %eax, %ecx > > + > > + /* We can't reuse either of the old comparisons as since we mask > > + of zeros after first zero (instead of using the full > > + comparison) we can't gurantee no interference between match > > + after end of string and valid match. */ > > + pmovmskb %xmm4, %eax > > + pmovmskb %xmm7, %edx > > + sall $16, %edx > > + orl %edx, %eax > > + > > + leal -1(%ecx), %edx > > + xorl %edx, %ecx > > + andl %ecx, %eax > > + jz L(second_loop_old_match) > > + bsrl %eax, %eax > > + addq %rdi, %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > + ret > > + > > + .p2align 4,, 4 > > L(cross_page): > > - movq %rdi, %rax > > - pxor %xmm0, %xmm0 > > - andq $-64, %rax > > - movdqu (%rax), %xmm5 > > - movdqa %xmm5, %xmm6 > > - movdqu 16(%rax), %xmm4 > > - pcmpeqb %xmm1, %xmm5 > > - pcmpeqb %xmm0, %xmm6 > > - movdqu 32(%rax), %xmm3 > > - pmovmskb %xmm6, %esi > > - movdqa %xmm4, %xmm6 > > - movdqu 48(%rax), %xmm2 > > - pcmpeqb %xmm1, %xmm4 > > - pcmpeqb %xmm0, %xmm6 > > - pmovmskb %xmm6, %edx > > - movdqa %xmm3, %xmm6 > > - pcmpeqb %xmm1, %xmm3 > > - pcmpeqb %xmm0, %xmm6 > > - pcmpeqb %xmm2, %xmm0 > > - salq $16, %rdx > > - pmovmskb %xmm3, %r9d > > - pmovmskb %xmm6, %r8d > > - pmovmskb %xmm0, %ecx > > - salq $32, %r9 > > - salq $32, %r8 > > - pcmpeqb %xmm1, %xmm2 > > - orq %r8, %rdx > > - salq $48, %rcx > > - pmovmskb %xmm5, %r8d > > - orq %rsi, %rdx > > - pmovmskb %xmm4, %esi > > - orq %rcx, %rdx > > - pmovmskb %xmm2, %ecx > > - salq $16, %rsi > > - salq $48, %rcx > > - orq %r9, %rsi > > - orq %r8, %rsi > > - orq %rcx, %rsi > > + movq %rdi, %rsi > > + andq $-VEC_SIZE, %rsi > > + movaps (%rsi), %xmm1 > > + pxor %xmm2, %xmm2 > > + PCMPEQ %xmm1, %xmm2 > > + pmovmskb %xmm2, %edx > > movl %edi, %ecx > > - subl %eax, %ecx > > - shrq %cl, %rdx > > - shrq %cl, %rsi > > - testq %rdx, %rdx > > - je L(loop_header2) > > - leaq -1(%rdx), %rax > > - xorq %rdx, %rax > > - andq %rax, %rsi > > - je L(exit) > > - bsrq %rsi, %rax > > + andl $(VEC_SIZE - 1), %ecx > > + sarl %cl, %edx > > + jz L(cross_page_continue) > > + PCMPEQ %xmm0, %xmm1 > > + pmovmskb %xmm1, %eax > > + sarl %cl, %eax > > + leal -1(%rdx), %ecx > > + xorl %edx, %ecx > > + andl %ecx, %eax > > + jz L(ret1) > > + bsrl %eax, %eax > > addq %rdi, %rax > > +#ifdef USE_AS_WCSRCHR > > + andq $-CHAR_SIZE, %rax > > +#endif > > +L(ret1): > > ret > > -END (strrchr) > > +END(STRRCHR) > > > > -weak_alias (strrchr, rindex) > > -libc_hidden_builtin_def (strrchr) > > +#ifndef USE_AS_WCSRCHR > > + weak_alias (STRRCHR, rindex) > > + libc_hidden_builtin_def (STRRCHR) > > +#endif > > diff --git a/sysdeps/x86_64/wcsrchr.S b/sysdeps/x86_64/wcsrchr.S > > index 61552954de..2b80efc5ef 100644 > > --- a/sysdeps/x86_64/wcsrchr.S > > +++ b/sysdeps/x86_64/wcsrchr.S > > @@ -1,4 +1,4 @@ > > -/* wcsrchr with SSSE3 > > +/* wcsrchr optimized with SSE2. > > Copyright (C) 2011-2022 Free Software Foundation, Inc. > > This file is part of the GNU C Library. > > > > @@ -16,266 +16,12 @@ > > License along with the GNU C Library; if not, see > > . */ > > > > -#include > > > > - .text > > -ENTRY (wcsrchr) > > +#define USE_AS_WCSRCHR 1 > > +#define NO_PMINU 1 > > > > - movd %rsi, %xmm1 > > - mov %rdi, %rcx > > - punpckldq %xmm1, %xmm1 > > - pxor %xmm2, %xmm2 > > - punpckldq %xmm1, %xmm1 > > - and $63, %rcx > > - cmp $48, %rcx > > - ja L(crosscache) > > +#ifndef STRRCHR > > +# define STRRCHR wcsrchr > > +#endif > > > > - movdqu (%rdi), %xmm0 > > - pcmpeqd %xmm0, %xmm2 > > - pcmpeqd %xmm1, %xmm0 > > - pmovmskb %xmm2, %rcx > > - pmovmskb %xmm0, %rax > > - add $16, %rdi > > - > > - test %rax, %rax > > - jnz L(unaligned_match1) > > - > > - test %rcx, %rcx > > - jnz L(return_null) > > - > > - and $-16, %rdi > > - xor %r8, %r8 > > - jmp L(loop) > > - > > - .p2align 4 > > -L(unaligned_match1): > > - test %rcx, %rcx > > - jnz L(prolog_find_zero_1) > > - > > - mov %rax, %r8 > > - mov %rdi, %rsi > > - and $-16, %rdi > > - jmp L(loop) > > - > > - .p2align 4 > > -L(crosscache): > > - and $15, %rcx > > - and $-16, %rdi > > - pxor %xmm3, %xmm3 > > - movdqa (%rdi), %xmm0 > > - pcmpeqd %xmm0, %xmm3 > > - pcmpeqd %xmm1, %xmm0 > > - pmovmskb %xmm3, %rdx > > - pmovmskb %xmm0, %rax > > - shr %cl, %rdx > > - shr %cl, %rax > > - add $16, %rdi > > - > > - test %rax, %rax > > - jnz L(unaligned_match) > > - > > - test %rdx, %rdx > > - jnz L(return_null) > > - > > - xor %r8, %r8 > > - jmp L(loop) > > - > > - .p2align 4 > > -L(unaligned_match): > > - test %rdx, %rdx > > - jnz L(prolog_find_zero) > > - > > - mov %rax, %r8 > > - lea (%rdi, %rcx), %rsi > > - > > -/* Loop start on aligned string. */ > > - .p2align 4 > > -L(loop): > > - movdqa (%rdi), %xmm0 > > - pcmpeqd %xmm0, %xmm2 > > - add $16, %rdi > > - pcmpeqd %xmm1, %xmm0 > > - pmovmskb %xmm2, %rcx > > - pmovmskb %xmm0, %rax > > - or %rax, %rcx > > - jnz L(matches) > > - > > - movdqa (%rdi), %xmm3 > > - pcmpeqd %xmm3, %xmm2 > > - add $16, %rdi > > - pcmpeqd %xmm1, %xmm3 > > - pmovmskb %xmm2, %rcx > > - pmovmskb %xmm3, %rax > > - or %rax, %rcx > > - jnz L(matches) > > - > > - movdqa (%rdi), %xmm4 > > - pcmpeqd %xmm4, %xmm2 > > - add $16, %rdi > > - pcmpeqd %xmm1, %xmm4 > > - pmovmskb %xmm2, %rcx > > - pmovmskb %xmm4, %rax > > - or %rax, %rcx > > - jnz L(matches) > > - > > - movdqa (%rdi), %xmm5 > > - pcmpeqd %xmm5, %xmm2 > > - add $16, %rdi > > - pcmpeqd %xmm1, %xmm5 > > - pmovmskb %xmm2, %rcx > > - pmovmskb %xmm5, %rax > > - or %rax, %rcx > > - jz L(loop) > > - > > - .p2align 4 > > -L(matches): > > - test %rax, %rax > > - jnz L(match) > > -L(return_value): > > - test %r8, %r8 > > - jz L(return_null) > > - mov %r8, %rax > > - mov %rsi, %rdi > > - > > - test $15 << 4, %ah > > - jnz L(match_fourth_wchar) > > - test %ah, %ah > > - jnz L(match_third_wchar) > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(match): > > - pmovmskb %xmm2, %rcx > > - test %rcx, %rcx > > - jnz L(find_zero) > > - mov %rax, %r8 > > - mov %rdi, %rsi > > - jmp L(loop) > > - > > - .p2align 4 > > -L(find_zero): > > - test $15, %cl > > - jnz L(find_zero_in_first_wchar) > > - test %cl, %cl > > - jnz L(find_zero_in_second_wchar) > > - test $15, %ch > > - jnz L(find_zero_in_third_wchar) > > - > > - and $1 << 13 - 1, %rax > > - jz L(return_value) > > - > > - test $15 << 4, %ah > > - jnz L(match_fourth_wchar) > > - test %ah, %ah > > - jnz L(match_third_wchar) > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(find_zero_in_first_wchar): > > - test $1, %rax > > - jz L(return_value) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(find_zero_in_second_wchar): > > - and $1 << 5 - 1, %rax > > - jz L(return_value) > > - > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(find_zero_in_third_wchar): > > - and $1 << 9 - 1, %rax > > - jz L(return_value) > > - > > - test %ah, %ah > > - jnz L(match_third_wchar) > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(prolog_find_zero): > > - add %rcx, %rdi > > - mov %rdx, %rcx > > -L(prolog_find_zero_1): > > - test $15, %cl > > - jnz L(prolog_find_zero_in_first_wchar) > > - test %cl, %cl > > - jnz L(prolog_find_zero_in_second_wchar) > > - test $15, %ch > > - jnz L(prolog_find_zero_in_third_wchar) > > - > > - and $1 << 13 - 1, %rax > > - jz L(return_null) > > - > > - test $15 << 4, %ah > > - jnz L(match_fourth_wchar) > > - test %ah, %ah > > - jnz L(match_third_wchar) > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(prolog_find_zero_in_first_wchar): > > - test $1, %rax > > - jz L(return_null) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(prolog_find_zero_in_second_wchar): > > - and $1 << 5 - 1, %rax > > - jz L(return_null) > > - > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(prolog_find_zero_in_third_wchar): > > - and $1 << 9 - 1, %rax > > - jz L(return_null) > > - > > - test %ah, %ah > > - jnz L(match_third_wchar) > > - test $15 << 4, %al > > - jnz L(match_second_wchar) > > - lea -16(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(match_second_wchar): > > - lea -12(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(match_third_wchar): > > - lea -8(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(match_fourth_wchar): > > - lea -4(%rdi), %rax > > - ret > > - > > - .p2align 4 > > -L(return_null): > > - xor %rax, %rax > > - ret > > - > > -END (wcsrchr) > > +#include "../strrchr.S" > > -- > > 2.25.1 > > > > LGTM. > > Reviewed-by: H.J. Lu > > Thanks. > > -- > H.J. I would like to backport this patch to release branches. Any comments or objections? --Sunil