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mirror of https://github.com/golang/go synced 2024-11-22 06:04:39 -07:00

move cas out, add dummy runcgo.

R=rsc
APPROVED=rsc
DELTA=73  (45 added, 28 deleted, 0 changed)
OCL=35363
CL=35366
This commit is contained in:
Kai Backman 2009-10-05 21:52:10 -07:00
parent b691447207
commit d58b5fca45
3 changed files with 40 additions and 37 deletions

View File

@ -30,6 +30,7 @@ OFILES_386=\
# arm-specific object files
OFILES_arm=\
cas.$O\
memset.$O\
vlop.$O\
vlrt.$O\

View File

@ -213,47 +213,19 @@ TEXT sys·morestackx(SB), 7, $-4
MOVW $0, R1 // set frame size
B sys·morestack(SB)
// bool cas(int32 *val, int32 old, int32 new)
// Atomically:
// if(*val == old){
// *val = new;
// return 1;
// }else
// return 0;
#define LDREX(a,r) WORD $(0xe<<28|0x01900f9f | (a)<<16 | (r)<<12)
#define STREX(a,v,r) WORD $(0xe<<28|0x01800f90 | (a)<<16 | (r)<<12 | (v)<<0)
TEXT cas+0(SB),0,$12 /* r0 holds p */
MOVW 0(FP), R0
MOVW ov+4(FP), R1
MOVW nv+8(FP), R2
spin:
/* LDREX 0(R0),R3 */
LDREX(0,3)
CMP.S R3, R1
BNE fail
/* STREX 0(R0),R2,R4 */
STREX(0,2,4)
CMP.S $0, R4
BNE spin
MOVW $1, R0
RET
fail:
MOVW $0, R0
RET
// void jmpdefer(fn, sp);
// called from deferreturn.
// 1. pop the caller
// 2. sub 5 bytes from the callers return
// 3. jmp to the argument
// 1. grab stored LR for caller
// 2. sub 4 bytes to get back to BL deferreturn
// 3. B to fn
TEXT jmpdefer(SB), 7, $0
BL abort(SB)
// MOVL 4(SP), AX // fn
// MOVL 8(SP), BX // caller sp
// LEAL -4(BX), SP // caller sp after CALL
// SUBL $5, (SP) // return to CALL again
// JMP AX // but first run the deferred function
MOVW 0(SP), LR
MOVW $-4(LR), LR // BL deferreturn
MOVW 4(SP), R0 // fn
MOVW 8(SP), R1
MOVW $-4(R1), SP // correct for sp pointing to arg0, past stored lr
B (R0)
TEXT sys·memclr(SB),7,$20
MOVW 0(FP), R0
@ -281,6 +253,22 @@ TEXT sys·setcallerpc+0(SB),7,$0
// MOVL BX, -4(AX) // set calling pc
// RET
// runcgo(void(*fn)(void*), void *arg)
// Just call fn(arg), but first align the stack
// appropriately for the gcc ABI.
// TODO(kaib): figure out the arm-gcc ABI
TEXT runcgo(SB),7,$16
BL abort(SB)
// MOVL fn+0(FP), AX
// MOVL arg+4(FP), BX
// MOVL SP, CX
// ANDL $~15, SP // alignment for gcc ABI
// MOVL CX, 4(SP)
// MOVL BX, 0(SP)
// CALL AX
// MOVL 4(SP), SP
// RET
TEXT emptyfunc(SB),0,$0
RET

14
src/pkg/runtime/arm/cas.s Normal file
View File

@ -0,0 +1,14 @@
// Copyright 2009 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.
// bool cas(int32 *val, int32 old, int32 new)
// Atomically:
// if(*val == old){
// *val = new;
// return 1;
// }else
// return 0;
TEXT cas+0(SB),0,$12
TODO