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- /*
- * R4000 user-level atomic operations
- */
- #define LL(base, rt) WORD $((060<<26)|((base)<<21)|((rt)<<16))
- #define SC(base, rt) WORD $((070<<26)|((base)<<21)|((rt)<<16))
- #define NOOP WORD $0x27
- TEXT ainc(SB), 1, $-4 /* long ainc(long *); */
- TEXT _xinc(SB), 1, $-4 /* void _xinc(long *); */
- MOVW R1, R2 /* address of counter */
- loop: MOVW $1, R3
- LL(2, 1)
- NOOP
- ADDU R1, R3
- MOVW R3, R1 /* return new value */
- SC(2, 3)
- NOOP
- BEQ R3,loop
- RET
- TEXT adec(SB), 1, $-4 /* long adec(long*); */
- TEXT _xdec(SB), 1, $-4 /* long _xdec(long *); */
- MOVW R1, R2 /* address of counter */
- loop1: MOVW $-1, R3
- LL(2, 1)
- NOOP
- ADDU R1, R3
- MOVW R3, R1 /* return new value */
- SC(2, 3)
- NOOP
- BEQ R3,loop1
- RET
- /*
- * int cas(uint* p, int ov, int nv);
- */
- TEXT cas(SB), 1, $-4
- MOVW ov+4(FP), R2
- MOVW nv+8(FP), R3
- spincas:
- LL(1, 4) /* R4 = *R1 */
- NOOP
- BNE R2, R4, fail
- SC(1, 3) /* *R1 = R3 */
- NOOP
- BEQ R3, spincas /* R3 == 0 means store failed */
- MOVW $1, R1
- RET
- fail:
- MOVW $0, R1
- RET
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