ref: e9cedfb90ba2324ea5f3dd69fa71a69871f0c19c
dir: /sys/src/libthread/xincalpha.s/
TEXT _xdec(SB), $-8 MOVQ R0, R1 /* p */ dec1: MOVLL (R1), R0 /* *p */ SUBL $1, R0 MOVQ R0, R2 MOVLC R2, (R1) /* --(*p) */ BEQ R2, dec1 /* write failed, retry */ RET TEXT _xinc(SB), $-8 MOVQ R0, R1 /* p */ inc1: MOVLL (R1), R0 /* *p */ ADDL $1, R0 MOVLC R0, (R1) /* (*p)++ */ BEQ R0, inc1 /* write failed, retry */ RET