d, borrow := bits.Sub64(x, y, 0)
	return x - d&(-borrow)
}

func foldConst(x, y uint64) uint64 {
	// arm64: "ADDS\t[$]7",-"MOVD\t[$]7"
	d, b := bits.Add64(x, 7, 0)
	return b & d
}

func foldConstOutOfRange(a uint64) uint64 {
	// arm64: "MOVD\t[$]19088744",-"ADD\t[$]19088744"
	return a + 0x1234568
}

// Verify sign-extended values are not zero-extended under a bit mask (#61297)