sys/src/libthread/xincalpha.s

   1 TEXT    _xdec(SB), $-8
   2         MOVQ    R0, R1          /* p */
   3 dec1:
   4         MOVLL   (R1), R0                /* *p */
   5         SUBL            $1, R0
   6         MOVQ    R0, R2
   7         MOVLC   R2, (R1)                /* --(*p) */
   8         BEQ             R2, dec1                /* write failed, retry */
   9         RET
  10
  11 TEXT    _xinc(SB), $-8
  12         MOVQ    R0, R1          /* p */
  13 inc1:
  14         MOVLL   (R1), R0                /* *p */
  15         ADDL    $1, R0
  16         MOVLC   R0, (R1)                /* (*p)++ */
  17         BEQ             R0, inc1                /* write failed, retry */
  18         RET
  19