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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:14:23 +0000 |
| commit | 73df946d56c74384511a194dd01dbe099584fd1a (patch) | |
| tree | fd0bcea490dd81327ddfbb31e215439672c9a068 /src/runtime/memclr_386.s | |
| parent | Initial commit. (diff) | |
| download | golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip | |
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/runtime/memclr_386.s')
| -rw-r--r-- | src/runtime/memclr_386.s | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/runtime/memclr_386.s b/src/runtime/memclr_386.s new file mode 100644 index 0000000..5e090ef --- /dev/null +++ b/src/runtime/memclr_386.s @@ -0,0 +1,138 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !plan9 + +#include "go_asm.h" +#include "textflag.h" + +// NOTE: Windows externalthreadhandler expects memclr to preserve DX. + +// See memclrNoHeapPointers Go doc for important implementation constraints. + +// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) +TEXT runtime·memclrNoHeapPointers(SB), NOSPLIT, $0-8 + MOVL ptr+0(FP), DI + MOVL n+4(FP), BX + XORL AX, AX + + // MOVOU seems always faster than REP STOSL. +tail: + // BSR+branch table make almost all memmove/memclr benchmarks worse. Not worth doing. + TESTL BX, BX + JEQ _0 + CMPL BX, $2 + JBE _1or2 + CMPL BX, $4 + JB _3 + JE _4 + CMPL BX, $8 + JBE _5through8 + CMPL BX, $16 + JBE _9through16 + CMPB internal∕cpu·X86+const_offsetX86HasSSE2(SB), $1 + JNE nosse2 + PXOR X0, X0 + CMPL BX, $32 + JBE _17through32 + CMPL BX, $64 + JBE _33through64 + CMPL BX, $128 + JBE _65through128 + CMPL BX, $256 + JBE _129through256 + +loop: + MOVOU X0, 0(DI) + MOVOU X0, 16(DI) + MOVOU X0, 32(DI) + MOVOU X0, 48(DI) + MOVOU X0, 64(DI) + MOVOU X0, 80(DI) + MOVOU X0, 96(DI) + MOVOU X0, 112(DI) + MOVOU X0, 128(DI) + MOVOU X0, 144(DI) + MOVOU X0, 160(DI) + MOVOU X0, 176(DI) + MOVOU X0, 192(DI) + MOVOU X0, 208(DI) + MOVOU X0, 224(DI) + MOVOU X0, 240(DI) + SUBL $256, BX + ADDL $256, DI + CMPL BX, $256 + JAE loop + JMP tail + +_1or2: + MOVB AX, (DI) + MOVB AX, -1(DI)(BX*1) + RET +_0: + RET +_3: + MOVW AX, (DI) + MOVB AX, 2(DI) + RET +_4: + // We need a separate case for 4 to make sure we clear pointers atomically. + MOVL AX, (DI) + RET +_5through8: + MOVL AX, (DI) + MOVL AX, -4(DI)(BX*1) + RET +_9through16: + MOVL AX, (DI) + MOVL AX, 4(DI) + MOVL AX, -8(DI)(BX*1) + MOVL AX, -4(DI)(BX*1) + RET +_17through32: + MOVOU X0, (DI) + MOVOU X0, -16(DI)(BX*1) + RET +_33through64: + MOVOU X0, (DI) + MOVOU X0, 16(DI) + MOVOU X0, -32(DI)(BX*1) + MOVOU X0, -16(DI)(BX*1) + RET +_65through128: + MOVOU X0, (DI) + MOVOU X0, 16(DI) + MOVOU X0, 32(DI) + MOVOU X0, 48(DI) + MOVOU X0, -64(DI)(BX*1) + MOVOU X0, -48(DI)(BX*1) + MOVOU X0, -32(DI)(BX*1) + MOVOU X0, -16(DI)(BX*1) + RET +_129through256: + MOVOU X0, (DI) + MOVOU X0, 16(DI) + MOVOU X0, 32(DI) + MOVOU X0, 48(DI) + MOVOU X0, 64(DI) + MOVOU X0, 80(DI) + MOVOU X0, 96(DI) + MOVOU X0, 112(DI) + MOVOU X0, -128(DI)(BX*1) + MOVOU X0, -112(DI)(BX*1) + MOVOU X0, -96(DI)(BX*1) + MOVOU X0, -80(DI)(BX*1) + MOVOU X0, -64(DI)(BX*1) + MOVOU X0, -48(DI)(BX*1) + MOVOU X0, -32(DI)(BX*1) + MOVOU X0, -16(DI)(BX*1) + RET +nosse2: + MOVL BX, CX + SHRL $2, CX + REP + STOSL + ANDL $3, BX + JNE tail + RET |