}
	return false
}

func s390xRegisterNumber(name string, n int16) (int16, bool) {
	switch name {
	case "AR":
		if 0 <= n && n <= 15 {
			return s390x.REG_AR0 + n, true
		}
	case "F":
		if 0 <= n && n <= 15 {
			return s390x.REG_F0 + n, true
		}
	case "R":
		if 0 <= n && n <= 15 {
			return s390x.REG_R0 + n, true
		}
	case "V":
		if 0 <= n && n <= 31 {
			return s390x.REG_V0 + n, true
		}
	}

	VP4DPWSSD 15(DX)(BX*8), [Z2-Z5], K4, Z17           // 62e26f4c528cda0f000000
	VP4DPWSSD 7(SI)(DI*1), [Z12-Z15], K4, Z17          // 62e21f4c528c3e07000000
	VP4DPWSSD 15(DX)(BX*8), [Z12-Z15], K4, Z17         // 62e21f4c528cda0f000000
	VP4DPWSSD 7(SI)(DI*1), [Z22-Z25], K4, Z17          // 62e24f44528c3e07000000
	VP4DPWSSD 15(DX)(BX*8), [Z22-Z25], K4, Z17         // 62e24f44528cda0f000000

	VPCLMULQDQ $97, 15(DX)(BX*8), Z26, Z24             // 62632d404484da0f00000061 or 6263ad404484da0f00000061
	VPCLMULQDQ $97, Z9, Z0, Z12                        // 62537d4844e161 or 6253fd4844e161
	VPCLMULQDQ $97, Z3, Z0, Z12                        // 62737d4844e361 or 6273fd4844e361
	VPCLMULQDQ $97, 7(SI)(DI*1), Z0, Z12               // 62737d4844a43e0700000061 or 6273fd4844a43e0700000061

		return
	}
	offset = (0xe << 24) | // opcode
		(op1 << 20) | // MCR/MRC
		((int64(bits) ^ arm.C_SCOND_XOR) << 28) | // scond
		((x0 & 15) << 8) | //coprocessor number
		((x1 & 7) << 21) | // coprocessor operation
		((x2 & 15) << 12) | // ARM register
		((x3 & 15) << 16) | // Crn
		((x4 & 15) << 0) | // Crm
		((x5 & 7) << 5) | // coprocessor information
		(1 << 4) /* must be set */
	return offset, arm.AMRC, true
}

	VPOPCNTD -15(R14)(R15*1), K5, Y26                  // 62027d2d55943ef1ffffff
	VPOPCNTD -15(BX), K5, Y26                          // 62627d2d5593f1ffffff
	VPOPCNTD Y22, K5, Y30                              // 62227d2d55f6
	VPOPCNTD Y3, K5, Y30                               // 62627d2d55f3
	VPOPCNTD Y15, K5, Y30                              // 62427d2d55f7

	"text/scanner"
)

type exprTest struct {
	input  string
	output int64
	atEOF  bool
}

var exprTests = []exprTest{
	// Simple
	{"0", 0, true},
	{"3", 3, true},
	{"070", 8 * 7, true},
	{"0x0f", 15, true},
	{"0xFF", 255, true},
	{"9223372036854775807", 9223372036854775807, true}, // max int64
	// Unary
	{"-0", 0, true},
	{"~0", -1, true},
	{"~0*0", 0, true},
	{"+3", 3, true},
	{"-3", -3, true},

	// Count the words.
	count := 0
	for scanner.Scan() {
		count++
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "reading input:", err)
	}
	fmt.Printf("%d\n", count)
	// Output: 15
}

// Use a Scanner with a custom split function (built by wrapping ScanWords) to validate
// 32-bit decimal input.
func ExampleScanner_custom() {
	// An artificial input source.