mirror of
https://github.com/golang/go
synced 2024-10-04 14:21:21 -06:00
8303a13bb8
On Plan 9, the kernel disallows the use of floating point instructions while handling a note. Previously, we worked around this by using a simple loop in place of memmove. When I added that work-around, I verified that all paths from the note handler didn't end up calling memmove. Now that memclr is using SSE instructions, the same process will have to be done again. Instead of doing that, however, this CL just punts and uses unoptimized functions everywhere on Plan 9. LGTM=rsc R=rsc, 0intro CC=golang-codereviews https://golang.org/cl/73830044
128 lines
2.8 KiB
ArmAsm
128 lines
2.8 KiB
ArmAsm
// Inferno's libkern/memmove-386.s
|
|
// http://code.google.com/p/inferno-os/source/browse/libkern/memmove-386.s
|
|
//
|
|
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
|
|
// Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com). All rights reserved.
|
|
// Portions Copyright 2009 The Go Authors. All rights reserved.
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to deal
|
|
// in the Software without restriction, including without limitation the rights
|
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in
|
|
// all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
// THE SOFTWARE.
|
|
|
|
#include "../../cmd/ld/textflag.h"
|
|
|
|
TEXT runtime·memmove(SB), NOSPLIT, $0-12
|
|
MOVL to+0(FP), DI
|
|
MOVL fr+4(FP), SI
|
|
MOVL n+8(FP), BX
|
|
|
|
// REP instructions have a high startup cost, so we handle small sizes
|
|
// with some straightline code. The REP MOVSL instruction is really fast
|
|
// for large sizes. The cutover is approximately 1K.
|
|
tail:
|
|
TESTL BX, BX
|
|
JEQ move_0
|
|
CMPL BX, $2
|
|
JBE move_1or2
|
|
CMPL BX, $4
|
|
JBE move_3or4
|
|
CMPL BX, $8
|
|
JBE move_5through8
|
|
CMPL BX, $16
|
|
JBE move_9through16
|
|
|
|
/*
|
|
* check and set for backwards
|
|
*/
|
|
CMPL SI, DI
|
|
JLS back
|
|
|
|
/*
|
|
* forward copy loop
|
|
*/
|
|
forward:
|
|
MOVL BX, CX
|
|
SHRL $2, CX
|
|
ANDL $3, BX
|
|
|
|
REP; MOVSL
|
|
JMP tail
|
|
/*
|
|
* check overlap
|
|
*/
|
|
back:
|
|
MOVL SI, CX
|
|
ADDL BX, CX
|
|
CMPL CX, DI
|
|
JLS forward
|
|
/*
|
|
* whole thing backwards has
|
|
* adjusted addresses
|
|
*/
|
|
|
|
ADDL BX, DI
|
|
ADDL BX, SI
|
|
STD
|
|
|
|
/*
|
|
* copy
|
|
*/
|
|
MOVL BX, CX
|
|
SHRL $2, CX
|
|
ANDL $3, BX
|
|
|
|
SUBL $4, DI
|
|
SUBL $4, SI
|
|
REP; MOVSL
|
|
|
|
CLD
|
|
ADDL $4, DI
|
|
ADDL $4, SI
|
|
SUBL BX, DI
|
|
SUBL BX, SI
|
|
JMP tail
|
|
|
|
move_1or2:
|
|
MOVB (SI), AX
|
|
MOVB -1(SI)(BX*1), CX
|
|
MOVB AX, (DI)
|
|
MOVB CX, -1(DI)(BX*1)
|
|
move_0:
|
|
RET
|
|
move_3or4:
|
|
MOVW (SI), AX
|
|
MOVW -2(SI)(BX*1), CX
|
|
MOVW AX, (DI)
|
|
MOVW CX, -2(DI)(BX*1)
|
|
RET
|
|
move_5through8:
|
|
MOVL (SI), AX
|
|
MOVL -4(SI)(BX*1), CX
|
|
MOVL AX, (DI)
|
|
MOVL CX, -4(DI)(BX*1)
|
|
RET
|
|
move_9through16:
|
|
MOVL (SI), AX
|
|
MOVL 4(SI), CX
|
|
MOVL -8(SI)(BX*1), DX
|
|
MOVL -4(SI)(BX*1), BP
|
|
MOVL AX, (DI)
|
|
MOVL CX, 4(DI)
|
|
MOVL DX, -8(DI)(BX*1)
|
|
MOVL BP, -4(DI)(BX*1)
|
|
RET
|