From patchwork Tue May 30 22:14:22 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 20646 Received: (qmail 76200 invoked by alias); 30 May 2017 22:14:24 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 76186 invoked by uid 89); 30 May 2017 22:14:23 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-24.1 required=5.0 tests=AWL, BAYES_00, FREEMAIL_FROM, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=ham version=3.3.2 spammy=bridge, Bridge, 1826 X-HELO: mail-qk0-f194.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=B8LT1jd/eqV126aUiVPmnSoOc4KED1k/yx3haYlXOic=; b=ELitEEVUk+J1FTgwsnAE7e3eQ/TpldZM9asPi/0sW928k9EnrLV6ENw2z7ZSl4GTke CoP7tpWhVR38Vrn6NQlvS9Ubk203cLAcj+g5dFr6xHDCrPeBqlSj7WHb2zMI728iVgUU Ew9d079ybTQAILWUSqcwVM1n0adqpV8WEw/ufv3h/DoSHLCu4ti0UV1cvTpLlm408c67 kfeSzBvGTSPBaSwDTUeNfMsqx9N97DIafjdP65WXaY8MsH3WKyj2XVz3Xqi9e5qyjH6J kZ1OwljkiOj9UoaKlAUl/9R4xiuzgBibFqMNSObL6/Lh8FAsW4GS0qGnzwlBrdFT9PGM z7hg== X-Gm-Message-State: AODbwcAh2d1ad3BWk9xjvtMxYRUdBKJQgTOePO0n2cdcGyZOu9cYRkMw vi8vde4tXz+zLM6Pobem4vbg9j/wbokN X-Received: by 10.55.1.79 with SMTP id 76mr25820916qkb.69.1496182463587; Tue, 30 May 2017 15:14:23 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20170520135619.GA17481@gmail.com> References: <20170520135619.GA17481@gmail.com> From: "H.J. Lu" Date: Tue, 30 May 2017 15:14:22 -0700 Message-ID: Subject: Re: [PATCH] x86-64: Update strlen.S to support wcslen/wcsnlen To: GNU C Library On Sat, May 20, 2017 at 6:56 AM, H.J. Lu wrote: > The difference between strlen and wcslen is byte vs int. We can > replace pminub and pcmpeqb with pminud and pcmpeqd to turn strlen > into wcslen. Tested on Ivy Bridge with benchtests/bench-wcslen.c, > the new strlen based wcslen is as fast as the old wcslen. > > OK for master? > > H.J. > --- > * sysdeps/x86_64/strlen.S (PMINU): New. > (PCMPEQ): Likewise. > (SHIFT_RETURN): Likewise. > (FIND_ZERO): Replace pcmpeqb with PCMPEQ. > (strlen): Add SHIFT_RETURN before ret. Replace pcmpeqb and > pminub with PCMPEQ and PMINU. > * sysdeps/x86_64/wcslen.S: Define AS_WCSLEN and strlen. > Include "strlen.S". > * sysdeps/x86_64/wcsnlen.S: New file. Here is the updated patch only with SSE2 wcsnlen.S. Any comments? From 5798d0fbf03c531dfcd8d145217a5fbfd2319d95 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sat, 20 May 2017 06:48:04 -0700 Subject: [PATCH] x86-64: Update strlen.S to support wcslen/wcsnlen The difference between strlen and wcslen is byte vs int. We can replace pminub and pcmpeqb with pminud and pcmpeqd to turn strlen/strnlen into wcslen/wcsnlen. The SSE2 wcsnlen is up to 4X faster on Haswell. * sysdeps/x86_64/strlen.S (PMINU): New. (PCMPEQ): Likewise. (SHIFT_RETURN): Likewise. (FIND_ZERO): Replace pcmpeqb with PCMPEQ. (strlen): Add SHIFT_RETURN before ret. Replace pcmpeqb and pminub with PCMPEQ and PMINU. * sysdeps/x86_64/wcsnlen.S: New file. --- sysdeps/x86_64/strlen.S | 61 +++++++++++++++++++++++++++++++----------------- sysdeps/x86_64/wcsnlen.S | 7 ++++++ 2 files changed, 47 insertions(+), 21 deletions(-) create mode 100644 sysdeps/x86_64/wcsnlen.S diff --git a/sysdeps/x86_64/strlen.S b/sysdeps/x86_64/strlen.S index 5896e6b9..b5ab117 100644 --- a/sysdeps/x86_64/strlen.S +++ b/sysdeps/x86_64/strlen.S @@ -1,4 +1,4 @@ -/* SSE2 version of strlen. +/* SSE2 version of strlen/wcslen. Copyright (C) 2012-2017 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -18,6 +18,16 @@ #include +#ifdef AS_WCSLEN +# define PMINU pminud +# define PCMPEQ pcmpeqd +# define SHIFT_RETURN shrq $2, %rax +#else +# define PMINU pminub +# define PCMPEQ pcmpeqb +# define SHIFT_RETURN +#endif + /* Long lived register in strlen(s), strnlen(s, n) are: %xmm3 - zero @@ -32,10 +42,10 @@ ENTRY(strlen) /* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx. */ #define FIND_ZERO \ - pcmpeqb (%rax), %xmm0; \ - pcmpeqb 16(%rax), %xmm1; \ - pcmpeqb 32(%rax), %xmm2; \ - pcmpeqb 48(%rax), %xmm3; \ + PCMPEQ (%rax), %xmm0; \ + PCMPEQ 16(%rax), %xmm1; \ + PCMPEQ 32(%rax), %xmm2; \ + PCMPEQ 48(%rax), %xmm3; \ pmovmskb %xmm0, %esi; \ pmovmskb %xmm1, %edx; \ pmovmskb %xmm2, %r8d; \ @@ -54,6 +64,9 @@ ENTRY(strlen) xor %rax, %rax ret L(n_nonzero): +# ifdef AS_WCSLEN + shlq $2, %rsi +# endif /* Initialize long lived registers. */ @@ -96,6 +109,7 @@ L(n_nonzero): test %rdx, %rdx; \ je L(lab); \ bsfq %rdx, %rax; \ + SHIFT_RETURN; \ ret #ifdef AS_STRNLEN @@ -104,19 +118,20 @@ L(n_nonzero): #else /* Test first 16 bytes unaligned. */ movdqu (%rax), %xmm4 - pcmpeqb %xmm0, %xmm4 + PCMPEQ %xmm0, %xmm4 pmovmskb %xmm4, %edx test %edx, %edx je L(next48_bytes) bsf %edx, %eax /* If eax is zeroed 16bit bsf can be used. */ + SHIFT_RETURN ret L(next48_bytes): /* Same as FIND_ZERO except we do not check first 16 bytes. */ andq $-16, %rax - pcmpeqb 16(%rax), %xmm1 - pcmpeqb 32(%rax), %xmm2 - pcmpeqb 48(%rax), %xmm3 + PCMPEQ 16(%rax), %xmm1 + PCMPEQ 32(%rax), %xmm2 + PCMPEQ 48(%rax), %xmm3 pmovmskb %xmm1, %edx pmovmskb %xmm2, %r8d pmovmskb %xmm3, %ecx @@ -145,6 +160,7 @@ L(strnlen_ret): test %rdx, %rdx je L(loop_init) bsfq %rdx, %rax + SHIFT_RETURN ret #endif .p2align 4 @@ -161,10 +177,10 @@ L(loop): je L(exit_end) movdqa (%rax), %xmm0 - pminub 16(%rax), %xmm0 - pminub 32(%rax), %xmm0 - pminub 48(%rax), %xmm0 - pcmpeqb %xmm3, %xmm0 + PMINU 16(%rax), %xmm0 + PMINU 32(%rax), %xmm0 + PMINU 48(%rax), %xmm0 + PCMPEQ %xmm3, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jne L(exit) @@ -182,6 +198,7 @@ L(first): bsfq %rdx, %rdx addq %rdx, %rax subq %rdi, %rax + SHIFT_RETURN ret .p2align 4 @@ -192,6 +209,7 @@ L(exit): bsfq %rdx, %rdx addq %rdx, %rax subq %rdi, %rax + SHIFT_RETURN ret #else @@ -201,10 +219,10 @@ L(exit): L(loop): movdqa 64(%rax), %xmm0 - pminub 80(%rax), %xmm0 - pminub 96(%rax), %xmm0 - pminub 112(%rax), %xmm0 - pcmpeqb %xmm3, %xmm0 + PMINU 80(%rax), %xmm0 + PMINU 96(%rax), %xmm0 + PMINU 112(%rax), %xmm0 + PCMPEQ %xmm3, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jne L(exit64) @@ -212,10 +230,10 @@ L(loop): subq $-128, %rax movdqa (%rax), %xmm0 - pminub 16(%rax), %xmm0 - pminub 32(%rax), %xmm0 - pminub 48(%rax), %xmm0 - pcmpeqb %xmm3, %xmm0 + PMINU 16(%rax), %xmm0 + PMINU 32(%rax), %xmm0 + PMINU 48(%rax), %xmm0 + PCMPEQ %xmm3, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jne L(exit0) @@ -231,6 +249,7 @@ L(exit0): bsfq %rdx, %rdx addq %rdx, %rax subq %rdi, %rax + SHIFT_RETURN ret #endif diff --git a/sysdeps/x86_64/wcsnlen.S b/sysdeps/x86_64/wcsnlen.S new file mode 100644 index 0000000..968bb69 --- /dev/null +++ b/sysdeps/x86_64/wcsnlen.S @@ -0,0 +1,7 @@ +#define AS_WCSLEN +#define AS_STRNLEN +#define strlen __wcsnlen + +#include "strlen.S" + +weak_alias(__wcsnlen, wcsnlen) -- 2.9.4