// Stack layout, depending on call path:
	//  x(SP)   vDSO            INVOKE_SYSCALL
	//    12    ts.tv_nsec      ts.tv_nsec
	//     8    ts.tv_sec       ts.tv_sec
	//     4    &ts             -
	//     0    CLOCK_<id>      -

	MOVL	runtime·vdsoClockgettimeSym(SB), AX
	CMPL	AX, $0
	JEQ	fallback

	LEAL	8(SP), BX	// &ts (struct timespec)
	MOVL	BX, 4(SP)
	MOVL	$0, 0(SP)	// CLOCK_REALTIME
	CALL	AX
	JMP finish