ref: cb3f6ebad0a54a603fd1a7405e599764fd9c02e5
dir: /sys/src/libc/amd64/atomic64.s/
/* get variants */ TEXT agetv+0(SB),1,$0 MOVQ (RARG), AX RET /* set variants */ TEXT aswapv+0(SB),1,$0 MOVQ v+8(FP), AX LOCK; XCHGQ (RARG), AX RET /* inc variants */ TEXT aincv+0(SB),1,$0 MOVQ v+8(FP), BX MOVQ BX, AX LOCK; XADDQ AX, (RARG) ADDQ BX, AX RET /* cas variants */ TEXT acasv+0(SB),1,$0 MOVQ c+8(FP), AX MOVQ v+16(FP), BX LOCK; CMPXCHGQ BX, (RARG) SETEQ AX MOVBLZX AX, AX RET