From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1039) id 1836B385800B; Wed, 9 Feb 2022 00:40:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1836B385800B Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: H.J. Lu To: glibc-cvs@sourceware.org Subject: [glibc] x86-64: Optimize bzero X-Act-Checkin: glibc X-Git-Author: H.J. Lu X-Git-Refname: refs/heads/master X-Git-Oldrev: dc98eeeb952f59bdbd51da0409e732756fe30170 X-Git-Newrev: 3d9f171bfb5325bd5f427e9fc386453358c6e840 Message-Id: <20220209004021.1836B385800B@sourceware.org> Date: Wed, 9 Feb 2022 00:40:21 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Feb 2022 00:40:21 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=3d9f171bfb5325bd5f427e9fc386453358c6e840 commit 3d9f171bfb5325bd5f427e9fc386453358c6e840 Author: H.J. Lu Date: Mon Feb 7 05:55:15 2022 -0800 x86-64: Optimize bzero memset with zero as the value to set is by far the majority value (99%+ for Python3 and GCC). bzero can be slightly more optimized for this case by using a zero-idiom xor for broadcasting the set value to a register (vector or GPR). Co-developed-by: Noah Goldstein Diff: --- sysdeps/x86_64/memset.S | 8 ++ sysdeps/x86_64/multiarch/Makefile | 1 + sysdeps/x86_64/multiarch/bzero.c | 106 ++++++++++++++++++++ sysdeps/x86_64/multiarch/ifunc-impl-list.c | 42 ++++++++ .../multiarch/memset-avx2-unaligned-erms-rtm.S | 1 + .../x86_64/multiarch/memset-avx2-unaligned-erms.S | 6 ++ .../multiarch/memset-avx512-unaligned-erms.S | 3 + .../x86_64/multiarch/memset-evex-unaligned-erms.S | 3 + .../x86_64/multiarch/memset-sse2-unaligned-erms.S | 1 + .../x86_64/multiarch/memset-vec-unaligned-erms.S | 110 ++++++++++++++++----- 10 files changed, 256 insertions(+), 25 deletions(-) diff --git a/sysdeps/x86_64/memset.S b/sysdeps/x86_64/memset.S index 3f0517bbfc..af26e9cedc 100644 --- a/sysdeps/x86_64/memset.S +++ b/sysdeps/x86_64/memset.S @@ -35,6 +35,9 @@ punpcklwd %xmm0, %xmm0; \ pshufd $0, %xmm0, %xmm0 +# define BZERO_ZERO_VEC0() \ + pxor %xmm0, %xmm0 + # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \ movd d, %xmm0; \ pshufd $0, %xmm0, %xmm0; \ @@ -53,6 +56,10 @@ # define MEMSET_SYMBOL(p,s) memset #endif +#ifndef BZERO_SYMBOL +# define BZERO_SYMBOL(p,s) __bzero +#endif + #ifndef WMEMSET_SYMBOL # define WMEMSET_CHK_SYMBOL(p,s) p # define WMEMSET_SYMBOL(p,s) __wmemset @@ -63,6 +70,7 @@ libc_hidden_builtin_def (memset) #if IS_IN (libc) +weak_alias (__bzero, bzero) libc_hidden_def (__wmemset) weak_alias (__wmemset, wmemset) libc_hidden_weak (wmemset) diff --git a/sysdeps/x86_64/multiarch/Makefile b/sysdeps/x86_64/multiarch/Makefile index 4274bfdd0d..e7b413edad 100644 --- a/sysdeps/x86_64/multiarch/Makefile +++ b/sysdeps/x86_64/multiarch/Makefile @@ -1,6 +1,7 @@ ifeq ($(subdir),string) sysdep_routines += \ + bzero \ memchr-avx2 \ memchr-avx2-rtm \ memchr-evex \ diff --git a/sysdeps/x86_64/multiarch/bzero.c b/sysdeps/x86_64/multiarch/bzero.c new file mode 100644 index 0000000000..58a14b2c33 --- /dev/null +++ b/sysdeps/x86_64/multiarch/bzero.c @@ -0,0 +1,106 @@ +/* Multiple versions of bzero. + All versions must be listed in ifunc-impl-list.c. + Copyright (C) 2022 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 + . */ + +/* Define multiple versions only for the definition in libc. */ +#if IS_IN (libc) +# define __bzero __redirect___bzero +# include +# undef __bzero + +# define SYMBOL_NAME __bzero +# include + +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (sse2_unaligned_erms) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned) attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_rtm) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx2_unaligned_erms_rtm) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (evex_unaligned_erms) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned) + attribute_hidden; +extern __typeof (REDIRECT_NAME) OPTIMIZE1 (avx512_unaligned_erms) + attribute_hidden; + +static inline void * +IFUNC_SELECTOR (void) +{ + const struct cpu_features* cpu_features = __get_cpu_features (); + + if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F) + && !CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_AVX512)) + { + if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL) + && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW) + && CPU_FEATURE_USABLE_P (cpu_features, BMI2)) + { + if (CPU_FEATURE_USABLE_P (cpu_features, ERMS)) + return OPTIMIZE1 (avx512_unaligned_erms); + + return OPTIMIZE1 (avx512_unaligned); + } + } + + if (CPU_FEATURE_USABLE_P (cpu_features, AVX2)) + { + if (CPU_FEATURE_USABLE_P (cpu_features, AVX512VL) + && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW) + && CPU_FEATURE_USABLE_P (cpu_features, BMI2)) + { + if (CPU_FEATURE_USABLE_P (cpu_features, ERMS)) + return OPTIMIZE1 (evex_unaligned_erms); + + return OPTIMIZE1 (evex_unaligned); + } + + if (CPU_FEATURE_USABLE_P (cpu_features, RTM)) + { + if (CPU_FEATURE_USABLE_P (cpu_features, ERMS)) + return OPTIMIZE1 (avx2_unaligned_erms_rtm); + + return OPTIMIZE1 (avx2_unaligned_rtm); + } + + if (!CPU_FEATURES_ARCH_P (cpu_features, Prefer_No_VZEROUPPER)) + { + if (CPU_FEATURE_USABLE_P (cpu_features, ERMS)) + return OPTIMIZE1 (avx2_unaligned_erms); + + return OPTIMIZE1 (avx2_unaligned); + } + } + + if (CPU_FEATURE_USABLE_P (cpu_features, ERMS)) + return OPTIMIZE1 (sse2_unaligned_erms); + + return OPTIMIZE1 (sse2_unaligned); +} + +libc_ifunc_redirected (__redirect___bzero, __bzero, IFUNC_SELECTOR ()); + +weak_alias (__bzero, bzero) +#endif diff --git a/sysdeps/x86_64/multiarch/ifunc-impl-list.c b/sysdeps/x86_64/multiarch/ifunc-impl-list.c index 68a56797d4..a594f4176e 100644 --- a/sysdeps/x86_64/multiarch/ifunc-impl-list.c +++ b/sysdeps/x86_64/multiarch/ifunc-impl-list.c @@ -300,6 +300,48 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array, __memset_avx512_no_vzeroupper) ) + /* Support sysdeps/x86_64/multiarch/bzero.c. */ + IFUNC_IMPL (i, name, bzero, + IFUNC_IMPL_ADD (array, i, bzero, 1, + __bzero_sse2_unaligned) + IFUNC_IMPL_ADD (array, i, bzero, 1, + __bzero_sse2_unaligned_erms) + IFUNC_IMPL_ADD (array, i, bzero, + CPU_FEATURE_USABLE (AVX2), + __bzero_avx2_unaligned) + IFUNC_IMPL_ADD (array, i, bzero, + CPU_FEATURE_USABLE (AVX2), + __bzero_avx2_unaligned_erms) + IFUNC_IMPL_ADD (array, i, bzero, + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (RTM)), + __bzero_avx2_unaligned_rtm) + IFUNC_IMPL_ADD (array, i, bzero, + (CPU_FEATURE_USABLE (AVX2) + && CPU_FEATURE_USABLE (RTM)), + __bzero_avx2_unaligned_erms_rtm) + IFUNC_IMPL_ADD (array, i, bzero, + (CPU_FEATURE_USABLE (AVX512VL) + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), + __bzero_evex_unaligned) + IFUNC_IMPL_ADD (array, i, bzero, + (CPU_FEATURE_USABLE (AVX512VL) + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), + __bzero_evex_unaligned_erms) + IFUNC_IMPL_ADD (array, i, bzero, + (CPU_FEATURE_USABLE (AVX512VL) + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), + __bzero_avx512_unaligned_erms) + IFUNC_IMPL_ADD (array, i, bzero, + (CPU_FEATURE_USABLE (AVX512VL) + && CPU_FEATURE_USABLE (AVX512BW) + && CPU_FEATURE_USABLE (BMI2)), + __bzero_avx512_unaligned) + ) + /* Support sysdeps/x86_64/multiarch/rawmemchr.c. */ IFUNC_IMPL (i, name, rawmemchr, IFUNC_IMPL_ADD (array, i, rawmemchr, diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S index 8ac3e479bb..5a5ee6f672 100644 --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms-rtm.S @@ -5,6 +5,7 @@ #define SECTION(p) p##.avx.rtm #define MEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm +#define BZERO_SYMBOL(p,s) p##_avx2_##s##_rtm #define WMEMSET_SYMBOL(p,s) p##_avx2_##s##_rtm #include "memset-avx2-unaligned-erms.S" diff --git a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S index c0bf2875d0..a093a2831f 100644 --- a/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S @@ -14,6 +14,9 @@ vmovd d, %xmm0; \ movq r, %rax; +# define BZERO_ZERO_VEC0() \ + vpxor %xmm0, %xmm0, %xmm0 + # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \ MEMSET_SET_VEC0_AND_SET_RETURN(d, r) @@ -29,6 +32,9 @@ # ifndef MEMSET_SYMBOL # define MEMSET_SYMBOL(p,s) p##_avx2_##s # endif +# ifndef BZERO_SYMBOL +# define BZERO_SYMBOL(p,s) p##_avx2_##s +# endif # ifndef WMEMSET_SYMBOL # define WMEMSET_SYMBOL(p,s) p##_avx2_##s # endif diff --git a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S index 5241216a77..727c92133a 100644 --- a/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S @@ -19,6 +19,9 @@ vpbroadcastb d, %VEC0; \ movq r, %rax +# define BZERO_ZERO_VEC0() \ + vpxorq %XMM0, %XMM0, %XMM0 + # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \ vpbroadcastd d, %VEC0; \ movq r, %rax diff --git a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S index 6370021506..5d8fa78f05 100644 --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S @@ -19,6 +19,9 @@ vpbroadcastb d, %VEC0; \ movq r, %rax +# define BZERO_ZERO_VEC0() \ + vpxorq %XMM0, %XMM0, %XMM0 + # define WMEMSET_SET_VEC0_AND_SET_RETURN(d, r) \ vpbroadcastd d, %VEC0; \ movq r, %rax diff --git a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S index 8a6f0c561a..329c58ee46 100644 --- a/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S @@ -22,6 +22,7 @@ #if IS_IN (libc) # define MEMSET_SYMBOL(p,s) p##_sse2_##s +# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s) # define WMEMSET_SYMBOL(p,s) p##_sse2_##s # ifdef SHARED diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S index 1b502b78e4..7c94fcdae1 100644 --- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S +++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S @@ -26,6 +26,10 @@ #include +#ifndef BZERO_SYMBOL +# define BZERO_SYMBOL(p,s) MEMSET_SYMBOL (p, s) +#endif + #ifndef MEMSET_CHK_SYMBOL # define MEMSET_CHK_SYMBOL(p,s) MEMSET_SYMBOL(p, s) #endif @@ -87,6 +91,18 @@ # define XMM_SMALL 0 #endif +#ifdef USE_LESS_VEC_MASK_STORE +# define SET_REG64 rcx +# define SET_REG32 ecx +# define SET_REG16 cx +# define SET_REG8 cl +#else +# define SET_REG64 rsi +# define SET_REG32 esi +# define SET_REG16 si +# define SET_REG8 sil +#endif + #define PAGE_SIZE 4096 /* Macro to calculate size of small memset block for aligning @@ -96,18 +112,6 @@ #ifndef SECTION # error SECTION is not defined! -#endif - - .section SECTION(.text),"ax",@progbits -#if VEC_SIZE == 16 && IS_IN (libc) -ENTRY (__bzero) - mov %RDI_LP, %RAX_LP /* Set return value. */ - mov %RSI_LP, %RDX_LP /* Set n. */ - xorl %esi, %esi - pxor %XMM0, %XMM0 - jmp L(entry_from_bzero) -END (__bzero) -weak_alias (__bzero, bzero) #endif #if IS_IN (libc) @@ -123,12 +127,37 @@ ENTRY (WMEMSET_SYMBOL (__wmemset, unaligned)) WMEMSET_SET_VEC0_AND_SET_RETURN (%esi, %rdi) WMEMSET_VDUP_TO_VEC0_LOW() cmpq $VEC_SIZE, %rdx - jb L(less_vec_no_vdup) + jb L(less_vec_from_wmemset) WMEMSET_VDUP_TO_VEC0_HIGH() jmp L(entry_from_wmemset) END (WMEMSET_SYMBOL (__wmemset, unaligned)) #endif +ENTRY (BZERO_SYMBOL(__bzero, unaligned)) +#if VEC_SIZE > 16 + BZERO_ZERO_VEC0 () +#endif + mov %RDI_LP, %RAX_LP + mov %RSI_LP, %RDX_LP +#ifndef USE_LESS_VEC_MASK_STORE + xorl %esi, %esi +#endif + cmp $VEC_SIZE, %RDX_LP + jb L(less_vec_no_vdup) +#ifdef USE_LESS_VEC_MASK_STORE + xorl %esi, %esi +#endif +#if VEC_SIZE <= 16 + BZERO_ZERO_VEC0 () +#endif + cmp $(VEC_SIZE * 2), %RDX_LP + ja L(more_2x_vec) + /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */ + VMOVU %VEC(0), (%rdi) + VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx) + VZEROUPPER_RETURN +END (BZERO_SYMBOL(__bzero, unaligned)) + #if defined SHARED && IS_IN (libc) ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned)) cmp %RDX_LP, %RCX_LP @@ -142,7 +171,6 @@ ENTRY (MEMSET_SYMBOL (__memset, unaligned)) /* Clear the upper 32 bits. */ mov %edx, %edx # endif -L(entry_from_bzero): cmpq $VEC_SIZE, %rdx jb L(less_vec) MEMSET_VDUP_TO_VEC0_HIGH() @@ -187,6 +215,31 @@ END (__memset_erms) END (MEMSET_SYMBOL (__memset, erms)) # endif +ENTRY_P2ALIGN (BZERO_SYMBOL(__bzero, unaligned_erms), 6) +# if VEC_SIZE > 16 + BZERO_ZERO_VEC0 () +# endif + mov %RDI_LP, %RAX_LP + mov %RSI_LP, %RDX_LP +# ifndef USE_LESS_VEC_MASK_STORE + xorl %esi, %esi +# endif + cmp $VEC_SIZE, %RDX_LP + jb L(less_vec_no_vdup) +# ifdef USE_LESS_VEC_MASK_STORE + xorl %esi, %esi +# endif +# if VEC_SIZE <= 16 + BZERO_ZERO_VEC0 () +# endif + cmp $(VEC_SIZE * 2), %RDX_LP + ja L(stosb_more_2x_vec) + /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */ + VMOVU %VEC(0), (%rdi) + VMOVU %VEC(0), (VEC_SIZE * -1)(%rdi, %rdx) + VZEROUPPER_RETURN +END (BZERO_SYMBOL(__bzero, unaligned_erms)) + # if defined SHARED && IS_IN (libc) ENTRY_CHK (MEMSET_CHK_SYMBOL (__memset_chk, unaligned_erms)) cmp %RDX_LP, %RCX_LP @@ -229,6 +282,7 @@ L(last_2x_vec): .p2align 4,, 10 L(less_vec): L(less_vec_no_vdup): +L(less_vec_from_wmemset): /* Less than 1 VEC. */ # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64 # error Unsupported VEC_SIZE! @@ -374,8 +428,11 @@ L(less_vec): /* Broadcast esi to partial register (i.e VEC_SIZE == 32 broadcast to xmm). This is only does anything for AVX2. */ MEMSET_VDUP_TO_VEC0_LOW () +L(less_vec_from_wmemset): +#if VEC_SIZE > 16 L(less_vec_no_vdup): #endif +#endif L(cross_page): #if VEC_SIZE > 32 cmpl $32, %edx @@ -386,7 +443,10 @@ L(cross_page): jge L(between_16_31) #endif #ifndef USE_XMM_LESS_VEC - MOVQ %XMM0, %rcx + MOVQ %XMM0, %SET_REG64 +#endif +#if VEC_SIZE <= 16 +L(less_vec_no_vdup): #endif cmpl $8, %edx jge L(between_8_15) @@ -395,7 +455,7 @@ L(cross_page): cmpl $1, %edx jg L(between_2_3) jl L(between_0_0) - movb %sil, (%LESS_VEC_REG) + movb %SET_REG8, (%LESS_VEC_REG) L(between_0_0): ret @@ -428,8 +488,8 @@ L(between_8_15): MOVQ %XMM0, (%rdi) MOVQ %XMM0, -8(%rdi, %rdx) #else - movq %rcx, (%LESS_VEC_REG) - movq %rcx, -8(%LESS_VEC_REG, %rdx) + movq %SET_REG64, (%LESS_VEC_REG) + movq %SET_REG64, -8(%LESS_VEC_REG, %rdx) #endif ret @@ -442,8 +502,8 @@ L(between_4_7): MOVD %XMM0, (%rdi) MOVD %XMM0, -4(%rdi, %rdx) #else - movl %ecx, (%LESS_VEC_REG) - movl %ecx, -4(%LESS_VEC_REG, %rdx) + movl %SET_REG32, (%LESS_VEC_REG) + movl %SET_REG32, -4(%LESS_VEC_REG, %rdx) #endif ret @@ -452,12 +512,12 @@ L(between_4_7): L(between_2_3): /* From 2 to 3. No branch when size == 2. */ #ifdef USE_XMM_LESS_VEC - movb %sil, (%rdi) - movb %sil, 1(%rdi) - movb %sil, -1(%rdi, %rdx) + movb %SET_REG8, (%rdi) + movb %SET_REG8, 1(%rdi) + movb %SET_REG8, -1(%rdi, %rdx) #else - movw %cx, (%LESS_VEC_REG) - movb %sil, -1(%LESS_VEC_REG, %rdx) + movw %SET_REG16, (%LESS_VEC_REG) + movb %SET_REG8, -1(%LESS_VEC_REG, %rdx) #endif ret END (MEMSET_SYMBOL (__memset, unaligned_erms))