throw("sem_init")
	}
	mp.waitsema = uintptr(unsafe.Pointer(sem))
}

//go:nosplit
func semasleep(ns int64) int32 {
	mp := getg().m
	if ns >= 0 {
		mp.ts.tv_sec = ns / 1000000000
		mp.ts.tv_nsec = ns % 1000000000

		mp.libcall.fn = uintptr(unsafe.Pointer(&libc_sem_reltimedwait_np))
		mp.libcall.n = 2
		mp.scratch = mscratch{}
		mp.scratch.v[0] = mp.waitsema

noswitch:
	SUBL	$16, SP		// Space for results
	ANDL	$~15, SP	// Align for C code

	// 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	AX, ret+24(FP)
	RET

TEXT runtime·usleep(SB),NOSPLIT,$16
	MOVL	$0, DX
	MOVL	usec+0(FP), AX
	MOVL	$1000000, CX
	DIVL	CX
	MOVQ	AX, 0(SP)		// tv_sec
	MOVL	$1000, AX
	MULL	DX
	MOVQ	AX, 8(SP)		// tv_nsec

	MOVQ	SP, DI			// arg 1 - rqtp
	MOVQ	$0, SI			// arg 2 - rmtp
	MOVL	$SYS___nanosleep50, AX
	SYSCALL
	RET

TEXT runtime·lwp_kill(SB),NOSPLIT,$0-16

	RET

TEXT runtime·usleep(SB),NOSPLIT,$16
	MOVW usec+0(FP), R0
	CALL runtime·usplitR0(SB)
	// 0(R13) is the saved LR, don't use it
	MOVW R0, 4(R13) // tv_sec.low
	MOVW $0, R0
	MOVW R0, 8(R13) // tv_sec.high
	MOVW $1000, R2
	MUL R1, R2
	MOVW R2, 12(R13) // tv_nsec

	MOVW $4(R13), R0 // arg 1 - rqtp
	MOVW $0, R1      // arg 2 - rmtp
	MOVW $SYS_nanosleep, R7
	SWI $0
	RET

TEXT runtime·usleep(SB),NOSPLIT,$16
	MOVW usec+0(FP), R0
	CALL runtime·usplitR0(SB)
	// 0(R13) is the saved LR, don't use it
	MOVW R0, 4(R13) // tv_sec.low
	MOVW $0, R0
	MOVW R0, 8(R13) // tv_sec.high
	MOVW $1000, R2
	MUL R1, R2
	MOVW R2, 12(R13) // tv_nsec

	MOVW $4(R13), R0 // arg 1 - rqtp
	MOVW $0, R1      // arg 2 - rmtp
	SWI $SYS___nanosleep50
	RET

TEXT runtime·lwp_kill(SB),NOSPLIT,$0-8

	if ret != 0 {
		print("runtime: failed to configure profiling timer; timer_settime(", timerid,
			", 0, {interval: {",
			spec.it_interval.tv_sec, "s + ", spec.it_interval.tv_nsec, "ns} value: {",
			spec.it_value.tv_sec, "s + ", spec.it_value.tv_nsec, "ns}}, nil) errno=", -ret, "\n")
		throw("timer_settime")
	}

	mp.profileTimer = timerid
	mp.profileTimerValid.Store(true)
}

	JCC	2(PC)
	MOVL	$0xf1, 0xf1  // crash
	RET

TEXT runtime·usleep(SB),NOSPLIT,$16
	MOVL	$0, DX
	MOVL	usec+0(FP), AX
	MOVL	$1000000, CX
	DIVL	CX
	MOVQ	AX, 0(SP)		// tv_sec
	MOVL	$1000, AX
	MULL	DX
	MOVQ	AX, 8(SP)		// tv_nsec

	MOVQ	SP, DI			// arg 1 - rqtp
	MOVQ	$0, SI			// arg 2 - rmtp
	MOVL	$SYS_nanosleep, AX
	SYSCALL
	RET

// set tls base to DI
TEXT runtime·settls(SB),NOSPLIT,$8

	RET

// func usleep(usec uint32)
TEXT runtime·usleep(SB),NOSPLIT,$16-4
	MOVWU	usec+0(FP), R7
	MOVV	$1000, R6
	MULVU	R6, R7, R7
	MOVV	$1000000000, R6

	DIVVU	R6, R7, R5	// ts->tv_sec
	REMVU	R6, R7, R4	// ts->tv_nsec
	MOVV	R5, 8(R3)
	MOVV	R4, 16(R3)

	// nanosleep(&ts, 0)
	ADDV	$8, R3, R4
	MOVV	R0, R5
	MOVV	$SYS_nanosleep, R11
	SYSCALL
	RET

// func gettid() uint32

	MOVD	$0x8637bd06, R4
	MULLD	R3, R4, R4	// Convert usec to S.
	SRD	$51, R4, R4
	MOVD	R4, 8(R1)	// Store to tv_sec

	MOVD	$1000000, R5
	MULLW	R4, R5, R5	// Convert tv_sec back into uS
	SUB	R5, R3, R5	// Compute remainder uS.
	MULLD	$1000, R5, R5	// Convert to nsec
	MOVD	R5, 16(R1)	// Store to tv_nsec

	// nanosleep(&ts, 0)
	ADD	$8, R1, R3
	MOVW	$0, R4
	SYSCALL	$SYS_nanosleep
	RET

//
//go:linkname walltime
//go:nosplit
//go:cgo_unsafe_args
func walltime() (int64, int32) {
	var t timespec
	libcCall(unsafe.Pointer(abi.FuncPCABI0(walltime_trampoline)), unsafe.Pointer(&t))
	return t.tv_sec, int32(t.tv_nsec)
}
func walltime_trampoline()

//go:nosplit
//go:cgo_unsafe_args
func sigaction(sig uint32, new *usigactiont, old *usigactiont) {