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go/src/pkg/runtime/memmove_amd64.s
Russ Cox 851f30136d runtime: make more build-friendly
Collapse the arch,os-specific directories into the main directory
by renaming xxx/foo.c to foo_xxx.c, and so on.

There are no substantial edits here, except to the Makefile.
The assumption is that the Go tool will #define GOOS_darwin
and GOARCH_amd64 and will make any file named something
like signals_darwin.h available as signals_GOOS.h during the
build.  This replaces what used to be done with -I$(GOOS).

There is still work to be done to make runtime build with
standard tools, but this is a big step.  After this we will have
to write a script to generate all the generated files so they
can be checked in (instead of generated during the build).

R=r, iant, r, lucio.dere
CC=golang-dev
https://golang.org/cl/5490053
2011-12-16 15:33:58 -05:00

89 lines
2.1 KiB
ArmAsm

// Derived from Inferno's libkern/memmove-386.s (adapted for amd64)
// 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.
TEXT runtime·memmove(SB), 7, $0
MOVQ to+0(FP), DI
MOVQ fr+8(FP), SI
MOVLQSX n+16(FP), BX
/*
* check and set for backwards
*/
CMPQ SI, DI
JLS back
/*
* forward copy loop
*/
forward:
MOVQ BX, CX
SHRQ $3, CX
ANDQ $7, BX
REP; MOVSQ
MOVQ BX, CX
REP; MOVSB
MOVQ to+0(FP),AX
RET
back:
/*
* check overlap
*/
MOVQ SI, CX
ADDQ BX, CX
CMPQ CX, DI
JLS forward
/*
* whole thing backwards has
* adjusted addresses
*/
ADDQ BX, DI
ADDQ BX, SI
STD
/*
* copy
*/
MOVQ BX, CX
SHRQ $3, CX
ANDQ $7, BX
SUBQ $8, DI
SUBQ $8, SI
REP; MOVSQ
ADDQ $7, DI
ADDQ $7, SI
MOVQ BX, CX
REP; MOVSB
CLD
MOVQ to+0(FP),AX
RET