From: Ondrej Bilka Date: Mon, 20 May 2013 06:20:00 +0000 (+0200) Subject: Faster memcpy on x64. X-Git-Tag: glibc-2.18~227 X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=2d48b41c8fa610067c4d664ac2339ae6ca43e78c;p=glibc.git Faster memcpy on x64. We add new memcpy version that uses unaligned loads which are fast on modern processors. This allows second improvement which is avoiding computed jump which is relatively expensive operation. Tests available here: http://kam.mff.cuni.cz/~ondra/memcpy_profile_result27_04_13.tar.bz2 --- diff --git a/ChangeLog b/ChangeLog index a2323faff4..6c540a7e23 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2013-05-20 Ondřej Bílka + + * sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S: New file. + * sysdeps/x86_64/multiarch/memcpy.S (__new_memcpy): Add + __memcpy_sse2_unaligned ifunc selection. + * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): + Add memcpy-sse2-unaligned.S. + * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): + Add: __memcpy_sse2_unaligned. + 2013-05-19 Joseph Myers [BZ #15490] diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile index 86787ee6ea..203d16eed3 100644 --- a/sysdeps/x86_64/multiarch/Makefile +++ b/sysdeps/x86_64/multiarch/Makefile @@ -7,7 +7,7 @@ endif ifeq ($(subdir),string) sysdep_routines += strncat-c stpncpy-c strncpy-c strcmp-ssse3 strncmp-ssse3 \ - strend-sse4 memcmp-sse4 memcpy-ssse3 mempcpy-ssse3 \ + strend-sse4 memcmp-sse4 memcpy-ssse3 memcpy-sse2-unaligned mempcpy-ssse3 \ memmove-ssse3 memcpy-ssse3-back mempcpy-ssse3-back \ memmove-ssse3-back strcasestr-nonascii strcasecmp_l-ssse3 \ strncase_l-ssse3 strcat-ssse3 strncat-ssse3\ diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c index 05315fdd7a..28d35793c5 100644 --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c @@ -227,6 +227,7 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, IFUNC_IMPL_ADD (array, i, memcpy, HAS_SSSE3, __memcpy_ssse3_back) IFUNC_IMPL_ADD (array, i, memcpy, HAS_SSSE3, __memcpy_ssse3) + IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_sse2_unaligned) IFUNC_IMPL_ADD (array, i, memcpy, 1, __memcpy_sse2)) /* Support sysdeps/x86_64/multiarch/mempcpy_chk.S. */ diff --git a/sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S b/sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S new file mode 100644 index 0000000000..efdfea238f --- /dev/null +++ b/sysdeps/x86_64/multiarch/memcpy-sse2-unaligned.S @@ -0,0 +1,175 @@ +/* memcpy with unaliged loads + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +#include "asm-syntax.h" + +#ifndef ALIGN +# define ALIGN(n) .p2align n +#endif + + +ENTRY(__memcpy_sse2_unaligned) + movq %rsi, %rax + leaq (%rdx,%rdx), %rcx + subq %rdi, %rax + subq %rdx, %rax + cmpq %rcx, %rax + jb L(overlapping) + cmpq $16, %rdx + jbe L(less_16) + movdqu (%rsi), %xmm8 + cmpq $32, %rdx + movdqu %xmm8, (%rdi) + movdqu -16(%rsi,%rdx), %xmm8 + movdqu %xmm8, -16(%rdi,%rdx) + ja .L31 +L(return): + movq %rdi, %rax + ret + .p2align 4,,10 + ALIGN(4) +.L31: + movdqu 16(%rsi), %xmm8 + cmpq $64, %rdx + movdqu %xmm8, 16(%rdi) + movdqu -32(%rsi,%rdx), %xmm8 + movdqu %xmm8, -32(%rdi,%rdx) + jbe L(return) + movdqu 32(%rsi), %xmm8 + cmpq $128, %rdx + movdqu %xmm8, 32(%rdi) + movdqu -48(%rsi,%rdx), %xmm8 + movdqu %xmm8, -48(%rdi,%rdx) + movdqu 48(%rsi), %xmm8 + movdqu %xmm8, 48(%rdi) + movdqu -64(%rsi,%rdx), %xmm8 + movdqu %xmm8, -64(%rdi,%rdx) + jbe L(return) + leaq 64(%rdi), %rcx + addq %rdi, %rdx + andq $-64, %rdx + andq $-64, %rcx + movq %rcx, %rax + subq %rdi, %rax + addq %rax, %rsi + cmpq %rdx, %rcx + je L(return) + movq %rsi, %r10 + subq %rcx, %r10 + leaq 16(%r10), %r9 + leaq 32(%r10), %r8 + leaq 48(%r10), %rax + .p2align 4,,10 + ALIGN(4) +L(loop): + movdqu (%rcx,%r10), %xmm8 + movdqa %xmm8, (%rcx) + movdqu (%rcx,%r9), %xmm8 + movdqa %xmm8, 16(%rcx) + movdqu (%rcx,%r8), %xmm8 + movdqa %xmm8, 32(%rcx) + movdqu (%rcx,%rax), %xmm8 + movdqa %xmm8, 48(%rcx) + addq $64, %rcx + cmpq %rcx, %rdx + jne L(loop) + jmp L(return) +L(overlapping): + cmpq %rsi, %rdi + jae .L3 + testq %rdx, %rdx + .p2align 4,,5 + je L(return) + movq %rdx, %r9 + leaq 16(%rsi), %rcx + leaq 16(%rdi), %r8 + shrq $4, %r9 + movq %r9, %rax + salq $4, %rax + cmpq %rcx, %rdi + setae %cl + cmpq %r8, %rsi + setae %r8b + orl %r8d, %ecx + cmpq $15, %rdx + seta %r8b + testb %r8b, %cl + je .L16 + testq %rax, %rax + je .L16 + xorl %ecx, %ecx + xorl %r8d, %r8d +.L7: + movdqu (%rsi,%rcx), %xmm8 + addq $1, %r8 + movdqu %xmm8, (%rdi,%rcx) + addq $16, %rcx + cmpq %r8, %r9 + ja .L7 + cmpq %rax, %rdx + je L(return) +.L21: + movzbl (%rsi,%rax), %ecx + movb %cl, (%rdi,%rax) + addq $1, %rax + cmpq %rax, %rdx + ja .L21 + jmp L(return) +L(less_16): + testb $24, %dl + jne L(between_9_16) + testb $4, %dl + .p2align 4,,5 + jne L(between_5_8) + testq %rdx, %rdx + .p2align 4,,2 + je L(return) + movzbl (%rsi), %eax + testb $2, %dl + movb %al, (%rdi) + je L(return) + movzwl -2(%rsi,%rdx), %eax + movw %ax, -2(%rdi,%rdx) + jmp L(return) +.L3: + leaq -1(%rdx), %rax + .p2align 4,,10 + ALIGN(4) +.L11: + movzbl (%rsi,%rax), %edx + movb %dl, (%rdi,%rax) + subq $1, %rax + jmp .L11 +L(between_9_16): + movq (%rsi), %rax + movq %rax, (%rdi) + movq -8(%rsi,%rdx), %rax + movq %rax, -8(%rdi,%rdx) + jmp L(return) +.L16: + xorl %eax, %eax + jmp .L21 +L(between_5_8): + movl (%rsi), %eax + movl %eax, (%rdi) + movl -4(%rsi,%rdx), %eax + movl %eax, -4(%rdi,%rdx) + jmp L(return) +END(__memcpy_sse2_unaligned) diff --git a/sysdeps/x86_64/multiarch/memcpy.S b/sysdeps/x86_64/multiarch/memcpy.S index b452f5304b..a1e5031376 100644 --- a/sysdeps/x86_64/multiarch/memcpy.S +++ b/sysdeps/x86_64/multiarch/memcpy.S @@ -33,13 +33,14 @@ ENTRY(__new_memcpy) jne 1f call __init_cpu_features 1: leaq __memcpy_sse2(%rip), %rax - testl $bit_SSSE3, __cpu_features+CPUID_OFFSET+index_SSSE3(%rip) - jz 2f - leaq __memcpy_ssse3(%rip), %rax - testl $bit_Fast_Copy_Backward, __cpu_features+FEATURE_OFFSET+index_Fast_Copy_Backward(%rip) - jz 2f - leaq __memcpy_ssse3_back(%rip), %rax -2: ret + testl $bit_Slow_BSF, __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip) + jnz 2f + leaq __memcpy_sse2_unaligned(%rip), %rax + ret +2: testl $bit_SSSE3, __cpu_features+CPUID_OFFSET+index_SSSE3(%rip) + jz 3f + leaq __memcpy_ssse3(%rip), %rax +3: ret END(__new_memcpy) # undef ENTRY