func signextendAndMask8to64(a int8) (s, z uint64) {
	// ppc64x: "MOVB", "ANDCC\t[$]1015,"
	s = uint64(a) & 0x3F7
	// ppc64x: -"MOVB", "ANDCC\t[$]247,"
	z = uint64(uint8(a)) & 0x3F7
	return
}

// Verify zero-extended values are not sign-extended under a bit mask (#61297)
func zeroextendAndMask8to64(a int8, b int16) (x, y uint64) {
	// ppc64x: -"MOVB\t", -"ANDCC", "MOVBZ"
	x = uint64(a) & 0xFF

	BLE	CR6, small	// <= 8
	BLT	CR7, xor32	// Case for 32 ≤ n < 64 bytes

	// Case for n ≥ 64 bytes
preloop64:
	SRD	$6, R6, R7	// Set up loop counter
	MOVD	R7, CTR
	MOVD	$16, R10
	MOVD	$32, R14
	MOVD	$48, R15
	ANDCC	$63, R6, R9	// Check for tailing bytes for later
	PCALIGN $16
	// Case for >= 64 bytes
	// Process 64 bytes per iteration
	// Load 4 vectors of a and b
	// XOR the corresponding vectors

	"ADDCV",
	"ADDCVCC",
	"ADDME",
	"ADDMECC",
	"ADDMEVCC",
	"ADDMEV",
	"ADDE",
	"ADDECC",
	"ADDEVCC",
	"ADDEV",
	"ADDZE",
	"ADDZECC",
	"ADDZEVCC",
	"ADDZEV",
	"ADDEX",
	"AND",
	"ANDCC",
	"ANDN",
	"ANDNCC",
	"ANDISCC",
	"BC",
	"BCL",
	"BEQ",
	"BGE",
	"BGT",
	"BLE",
	"BLT",
	"BNE",
	"BVC",
	"BVS",
	"BDNZ",
	"BDZ",
	"CMP",
	"CMPU",
	"CMPEQB",
	"CNTLZW",