diff options
Diffstat (limited to 'src/pkg/runtime/arm/asm.s')
| -rw-r--r-- | src/pkg/runtime/arm/asm.s | 41 |
1 files changed, 36 insertions, 5 deletions
diff --git a/src/pkg/runtime/arm/asm.s b/src/pkg/runtime/arm/asm.s index a4e4b3283..f9fe7e628 100644 --- a/src/pkg/runtime/arm/asm.s +++ b/src/pkg/runtime/arm/asm.s @@ -12,10 +12,10 @@ TEXT _rt0_arm(SB),7,$-4 // use R13 instead of SP to avoid linker rewriting the offsets MOVW 0(R13), R0 // argc MOVW $4(R13), R1 // argv - SUB $128, R13 // plenty of scratch + SUB $64, R13 // plenty of scratch AND $~7, R13 - MOVW R0, 120(R13) // save argc, argv away - MOVW R1, 124(R13) + MOVW R0, 60(R13) // save argc, argv away + MOVW R1, 64(R13) // set up m and g registers // g is R10, m is R9 @@ -34,9 +34,9 @@ TEXT _rt0_arm(SB),7,$-4 BL runtime·check(SB) // saved argc, argv - MOVW 120(R13), R0 + MOVW 60(R13), R0 MOVW R0, 4(R13) - MOVW 124(R13), R1 + MOVW 64(R13), R1 MOVW R1, 8(R13) BL runtime·args(SB) BL runtime·osinit(SB) @@ -274,3 +274,34 @@ TEXT runtime·abort(SB),7,$-4 TEXT runtime·runcgocallback(SB),7,$0 MOVW $0, R0 MOVW (R0), R1 + +// bool armcas(int32 *val, int32 old, int32 new) +// Atomically: +// if(*val == old){ +// *val = new; +// return 1; +// }else +// return 0; +// +// To implement runtime·cas in ../$GOOS/arm/sys.s +// using the native instructions, use: +// +// TEXT runtime·cas(SB),7,$0 +// B runtime·armcas(SB) +// +TEXT runtime·armcas(SB),7,$0 + MOVW valptr+0(FP), R1 + MOVW old+4(FP), R2 + MOVW new+8(FP), R3 +casl: + LDREX (R1), R0 + CMP R0, R2 + BNE casfail + STREX R3, (R1), R0 + CMP $0, R0 + BNE casl + MOVW $1, R0 + RET +casfail: + MOVW $0, R0 + RET |