BNE	tail63
	RET

try_zva:
	// Try using the ZVA feature to zero entire cache lines
	// It is not meaningful to use ZVA if the block size is less than 64,
	// so make sure that n is greater than or equal to 64
	CMP	$63, R1
	BLE	tail63

	CMP	$128, R1
	// Ensure n is at least 128 bytes, so that there is enough to copy after
	// alignment.
	BLT	no_zva
	// Check if ZVA is allowed from user code, and if so get the block size