#define RDTSC BYTE $0x0F; BYTE $0x31
TEXT	rdtsc(SB), $0	/* time stamp counter: cycles since power up */
	MOVL	.ret+0(FP), CX
	RDTSC
	MOVL	AX, 0(CX)
	MOVL	DX, 4(CX)
	RET