Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Browse files
Browse the repository at this point in the history
Add x86-64 memset with unaligned store and rep stosb
Implement x86-64 memset with unaligned store and rep movsb. Support 16-byte, 32-byte and 64-byte vector register sizes. A single file provides 2 implementations of memset, one with rep stosb and the other without rep stosb. They share the same codes when size is between 2 times of vector register size and REP_STOSB_THRESHOLD which defaults to 2KB. Key features: 1. Use overlapping store to avoid branch. 2. For size <= 4 times of vector register size, fully unroll the loop. 3. For size > 4 times of vector register size, store 4 times of vector register size at a time. [BZ #19881] * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memset-sse2-unaligned-erms, memset-avx2-unaligned-erms and memset-avx512-unaligned-erms. * sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list): Test __memset_chk_sse2_unaligned, __memset_chk_sse2_unaligned_erms, __memset_chk_avx2_unaligned, __memset_chk_avx2_unaligned_erms, __memset_chk_avx512_unaligned, __memset_chk_avx512_unaligned_erms, __memset_sse2_unaligned, __memset_sse2_unaligned_erms, __memset_erms, __memset_avx2_unaligned, __memset_avx2_unaligned_erms, __memset_avx512_unaligned_erms and __memset_avx512_unaligned. * sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S: New file. * sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset-sse2-unaligned-erms.S: Likewise. * sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: Likewise.
- Loading branch information
H.J. Lu
committed
Mar 31, 2016
1 parent
88b57b8
commit 8305663
Showing
7 changed files
with
358 additions
and
1 deletion.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,14 @@ | ||
| #define VEC_SIZE 32 | ||
| #define VEC(i) ymm##i | ||
| #define VMOVU vmovdqu | ||
| #define VMOVA vmovdqa | ||
|
|
||
| #define VDUP_TO_VEC0_AND_SET_RETURN(d, r) \ | ||
| vmovd d, %xmm0; \ | ||
| movq r, %rax; \ | ||
| vpbroadcastb %xmm0, %ymm0 | ||
|
|
||
| #define SECTION(p) p##.avx | ||
| #define MEMSET_SYMBOL(p,s) p##_avx2_##s | ||
|
|
||
| #include "memset-vec-unaligned-erms.S" |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,17 @@ | ||
| #ifdef HAVE_AVX512_ASM_SUPPORT | ||
| # define VEC_SIZE 64 | ||
| # define VEC(i) zmm##i | ||
| # define VMOVU vmovdqu64 | ||
| # define VMOVA vmovdqa64 | ||
|
|
||
| # define VDUP_TO_VEC0_AND_SET_RETURN(d, r) \ | ||
| vmovd d, %xmm0; \ | ||
| movq r, %rax; \ | ||
| vpbroadcastb %xmm0, %xmm0; \ | ||
| vpbroadcastq %xmm0, %zmm0 | ||
|
|
||
| # define SECTION(p) p##.avx512 | ||
| # define MEMSET_SYMBOL(p,s) p##_avx512_##s | ||
|
|
||
| # include "memset-vec-unaligned-erms.S" | ||
| #endif |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,16 @@ | ||
| #define VEC_SIZE 16 | ||
| #define VEC(i) xmm##i | ||
| #define VMOVU movdqu | ||
| #define VMOVA movdqa | ||
|
|
||
| #define VDUP_TO_VEC0_AND_SET_RETURN(d, r) \ | ||
| movd d, %xmm0; \ | ||
| movq r, %rax; \ | ||
| punpcklbw %xmm0, %xmm0; \ | ||
| punpcklwd %xmm0, %xmm0; \ | ||
| pshufd $0, %xmm0, %xmm0 | ||
|
|
||
| #define SECTION(p) p | ||
| #define MEMSET_SYMBOL(p,s) p##_sse2_##s | ||
|
|
||
| #include "memset-vec-unaligned-erms.S" |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,251 @@ | ||
| /* memset/bzero with unaligned store and rep stosb | ||
| Copyright (C) 2016 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 | ||
| <http://www.gnu.org/licenses/>. */ | ||
|
|
||
| /* memset is implemented as: | ||
| 1. Use overlapping store to avoid branch. | ||
| 2. Force 32-bit displacement for branches to avoid long nop between | ||
| instructions. | ||
| 3. If size is less than VEC, use integer register stores. | ||
| 4. If size is from VEC_SIZE to 2 * VEC_SIZE, use 2 VEC stores. | ||
| 5. If size is from 2 * VEC_SIZE to 4 * VEC_SIZE, use 4 VEC stores. | ||
| 6. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with | ||
| 4 VEC stores and store 4 * VEC at a time until done. */ | ||
|
|
||
| #include <sysdep.h> | ||
|
|
||
| #ifndef VZEROUPPER | ||
| # if VEC_SIZE > 16 | ||
| # define VZEROUPPER vzeroupper | ||
| # else | ||
| # define VZEROUPPER | ||
| # endif | ||
| #endif | ||
|
|
||
| #ifndef VZEROUPPER_SHORT_RETURN | ||
| # if VEC_SIZE > 16 | ||
| # define VZEROUPPER_SHORT_RETURN vzeroupper | ||
| # else | ||
| # define VZEROUPPER_SHORT_RETURN rep | ||
| # endif | ||
| #endif | ||
|
|
||
| #ifndef MOVQ | ||
| # if VEC_SIZE > 16 | ||
| # define MOVQ vmovq | ||
| # else | ||
| # define MOVQ movq | ||
| # endif | ||
| #endif | ||
|
|
||
| /* Threshold to use Enhanced REP STOSB. Since there is overhead to set | ||
| up REP STOSB operation, REP STOSB isn't faster on short data. The | ||
| memset micro benchmark in glibc shows that 2KB is the approximate | ||
| value above which REP STOSB becomes faster on processors with | ||
| Enhanced REP STOSB. Since the stored value is fixed, larger register | ||
| size has minimal impact on threshold. */ | ||
| #ifndef REP_STOSB_THRESHOLD | ||
| # define REP_STOSB_THRESHOLD 2048 | ||
| #endif | ||
|
|
||
| #ifndef SECTION | ||
| # error SECTION is not defined! | ||
| #endif | ||
|
|
||
| #if !defined USE_MULTIARCH && IS_IN (libc) | ||
| .section SECTION(.text),"ax",@progbits | ||
| ENTRY (__bzero) | ||
| movq %rdi, %rax /* Set return value. */ | ||
| movq %rsi, %rdx /* Set n. */ | ||
| pxor %xmm0, %xmm0 | ||
| jmp L(entry_from_bzero) | ||
| END (__bzero) | ||
| weak_alias (__bzero, bzero) | ||
| #endif | ||
|
|
||
| #if defined SHARED && IS_IN (libc) | ||
| ENTRY_CHK (MEMSET_SYMBOL (__memset_chk, unaligned)) | ||
| cmpq %rdx, %rcx | ||
| jb HIDDEN_JUMPTARGET (__chk_fail) | ||
| END_CHK (MEMSET_SYMBOL (__memset_chk, unaligned)) | ||
| #endif | ||
|
|
||
| ENTRY (MEMSET_SYMBOL (__memset, unaligned)) | ||
| L(memset_entry): | ||
| VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi) | ||
| L(entry_from_bzero): | ||
| cmpq $VEC_SIZE, %rdx | ||
| jb L(less_vec) | ||
| cmpq $(VEC_SIZE * 2), %rdx | ||
| ja L(more_2x_vec) | ||
| /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */ | ||
| VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx) | ||
| VMOVU %VEC(0), (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
| END (MEMSET_SYMBOL (__memset, unaligned)) | ||
|
|
||
| #if VEC_SIZE == 16 | ||
| /* Only used to measure performance of REP STOSB. */ | ||
| ENTRY (__memset_erms) | ||
| #else | ||
| /* Provide a symbol to debugger. */ | ||
| ENTRY (MEMSET_SYMBOL (__memset, erms)) | ||
| #endif | ||
| L(stosb): | ||
| movq %rdx, %rcx | ||
| movzbl %sil, %eax | ||
| movq %rdi, %rdx | ||
| rep stosb | ||
| movq %rdx, %rax | ||
| ret | ||
| #if VEC_SIZE == 16 | ||
| END (__memset_erms) | ||
| #else | ||
| END (MEMSET_SYMBOL (__memset, erms)) | ||
| #endif | ||
|
|
||
| #if defined SHARED && IS_IN (libc) | ||
| ENTRY_CHK (MEMSET_SYMBOL (__memset_chk, unaligned_erms)) | ||
| cmpq %rdx, %rcx | ||
| jb HIDDEN_JUMPTARGET (__chk_fail) | ||
| END_CHK (MEMSET_SYMBOL (__memset_chk, unaligned_erms)) | ||
| #endif | ||
|
|
||
| ENTRY (MEMSET_SYMBOL (__memset, unaligned_erms)) | ||
| VDUP_TO_VEC0_AND_SET_RETURN (%esi, %rdi) | ||
| cmpq $VEC_SIZE, %rdx | ||
| jb L(less_vec) | ||
| cmpq $(VEC_SIZE * 2), %rdx | ||
| ja L(stosb_more_2x_vec) | ||
| /* From VEC and to 2 * VEC. No branch when size == VEC_SIZE. */ | ||
| VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx) | ||
| VMOVU %VEC(0), (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
|
|
||
| .p2align 4 | ||
| L(stosb_more_2x_vec): | ||
| cmpq $REP_STOSB_THRESHOLD, %rdx | ||
| /* Force 32-bit displacement to avoid long nop between | ||
| instructions. */ | ||
| ja.d32 L(stosb) | ||
| .p2align 4 | ||
| L(more_2x_vec): | ||
| cmpq $(VEC_SIZE * 4), %rdx | ||
| ja L(loop_start) | ||
| VMOVU %VEC(0), (%rdi) | ||
| VMOVU %VEC(0), VEC_SIZE(%rdi) | ||
| VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx) | ||
| VMOVU %VEC(0), -(VEC_SIZE * 2)(%rdi,%rdx) | ||
| L(return): | ||
| VZEROUPPER | ||
| ret | ||
|
|
||
| .p2align 4 | ||
| L(loop_start): | ||
| leaq (VEC_SIZE * 4)(%rdi), %rcx | ||
| VMOVU %VEC(0), (%rdi) | ||
| andq $-(VEC_SIZE * 4), %rcx | ||
| VMOVU %VEC(0), -VEC_SIZE(%rdi,%rdx) | ||
| VMOVU %VEC(0), VEC_SIZE(%rdi) | ||
| VMOVU %VEC(0), -(VEC_SIZE * 2)(%rdi,%rdx) | ||
| VMOVU %VEC(0), (VEC_SIZE * 2)(%rdi) | ||
| VMOVU %VEC(0), -(VEC_SIZE * 3)(%rdi,%rdx) | ||
| VMOVU %VEC(0), (VEC_SIZE * 3)(%rdi) | ||
| VMOVU %VEC(0), -(VEC_SIZE * 4)(%rdi,%rdx) | ||
| addq %rdi, %rdx | ||
| andq $-(VEC_SIZE * 4), %rdx | ||
| cmpq %rdx, %rcx | ||
| # if VEC_SIZE == 32 || VEC_SIZE == 64 | ||
| /* Force 32-bit displacement to avoid long nop between | ||
| instructions. */ | ||
| je.d32 L(return) | ||
| # else | ||
| je L(return) | ||
| # endif | ||
| .p2align 4 | ||
| L(loop): | ||
| VMOVA %VEC(0), (%rcx) | ||
| VMOVA %VEC(0), VEC_SIZE(%rcx) | ||
| VMOVA %VEC(0), (VEC_SIZE * 2)(%rcx) | ||
| VMOVA %VEC(0), (VEC_SIZE * 3)(%rcx) | ||
| addq $(VEC_SIZE * 4), %rcx | ||
| cmpq %rcx, %rdx | ||
| jne L(loop) | ||
| VZEROUPPER_SHORT_RETURN | ||
| ret | ||
| L(less_vec): | ||
| /* Less than 1 VEC. */ | ||
| # if VEC_SIZE != 16 && VEC_SIZE != 32 && VEC_SIZE != 64 | ||
| # error Unsupported VEC_SIZE! | ||
| # endif | ||
| # if VEC_SIZE > 32 | ||
| cmpb $32, %dl | ||
| jae L(between_32_63) | ||
| # endif | ||
| # if VEC_SIZE > 16 | ||
| cmpb $16, %dl | ||
| jae L(between_16_31) | ||
| # endif | ||
| MOVQ %xmm0, %rcx | ||
| cmpb $8, %dl | ||
| jae L(between_8_15) | ||
| cmpb $4, %dl | ||
| jae L(between_4_7) | ||
| cmpb $1, %dl | ||
| ja L(between_2_3) | ||
| jb 1f | ||
| movb %cl, (%rdi) | ||
| 1: | ||
| VZEROUPPER | ||
| ret | ||
| # if VEC_SIZE > 32 | ||
| /* From 32 to 63. No branch when size == 32. */ | ||
| L(between_32_63): | ||
| vmovdqu %ymm0, -32(%rdi,%rdx) | ||
| vmovdqu %ymm0, (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
| # endif | ||
| # if VEC_SIZE > 16 | ||
| /* From 16 to 31. No branch when size == 16. */ | ||
| L(between_16_31): | ||
| vmovdqu %xmm0, -16(%rdi,%rdx) | ||
| vmovdqu %xmm0, (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
| # endif | ||
| /* From 8 to 15. No branch when size == 8. */ | ||
| L(between_8_15): | ||
| movq %rcx, -8(%rdi,%rdx) | ||
| movq %rcx, (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
| L(between_4_7): | ||
| /* From 4 to 7. No branch when size == 4. */ | ||
| movl %ecx, -4(%rdi,%rdx) | ||
| movl %ecx, (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
| L(between_2_3): | ||
| /* From 2 to 3. No branch when size == 2. */ | ||
| movw %cx, -2(%rdi,%rdx) | ||
| movw %cx, (%rdi) | ||
| VZEROUPPER | ||
| ret | ||
| END (MEMSET_SYMBOL (__memset, unaligned_erms)) |