}
	_ = *addr // if nil, fault before taking the lock
	var r uint64
	addrLock(addr).lock()
	r = *addr + uint64(delta)
	*addr = r
	addrLock(addr).unlock()
	return r
}

//go:nosplit
func goXchg64(addr *uint64, v uint64) uint64 {
	if uintptr(unsafe.Pointer(addr))&7 != 0 {
		*(*int)(nil) = 0 // crash on unaligned uint64
	}
	_ = *addr // if nil, fault before taking the lock
	var r uint64
	addrLock(addr).lock()

TEXT ·Xchg64(SB),NOSPLIT,$-4-20
	NO_LOCAL_POINTERS
	MOVW	addr+0(FP), R1
	CHECK_ALIGN

#ifndef GOARM_7
	MOVB	internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11
	CMP	$1, R11
	BEQ	2(PC)
	JMP	·goXchg64(SB)
#endif
	JMP	armXchg64<>(SB)

TEXT ·Load64(SB),NOSPLIT,$-4-12
	NO_LOCAL_POINTERS
	MOVW	addr+0(FP), R1
	CHECK_ALIGN

#ifndef GOARM_7
	MOVB	internal∕cpu·ARM+const_offsetARMHasV7Atomics(SB), R11