/* *	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), R3spincas:	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	RETfail:	MOVW	$0, R1	RET