func msDosTimeToTime(dosDate, dosTime uint16) time.Time {
	return time.Date(
		// date bits 0-4: day of month; 5-8: month; 9-15: years since 1980
		int(dosDate>>9+1980),
		time.Month(dosDate>>5&0xf),
		int(dosDate&0x1f),

		// time bits 0-4: second/2; 5-10: minute; 11-15: hour
		int(dosTime>>11),
		int(dosTime>>5&0x3f),
		int(dosTime&0x1f*2),
		0, // nanoseconds

		time.UTC,
	)
}

	// Make sure we find the correct byte even when straddling a page.
	for i := 0; i <= len(b)-15; i++ {
		for j := 0; j < 15; j++ {
			b[i+j] = byte(100 + j)
		}
		for j := 0; j < 15; j++ {
			p := IndexByte(b[i:i+15], byte(100+j))
			if p != j {
				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 100+j, p)
			}
		}
		for j := 0; j < 15; j++ {
			b[i+j] = 0
		}
	}
	// Make sure matches outside the slice never trigger.

	"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.

	}
	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
		}
	}

		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
}

		tests: []testFnc{
			testRemaining{15, 13},
			testRead{100, "\x00abc\x00\x00defgh\x00\x00\x00\x00", errUnrefData},
			testWriteTo{nil, 0, errUnrefData},
			testRemaining{0, 5},
		},
	}, {
		maker: makeSparse{makeReg{"abcdefghEXTRA", 13}, sparseDatas{{1, 3}, {6, 5}}, 15},
		tests: []testFnc{
			testRemaining{15, 13},

00000f0 ff 42 88 21 c4 00 00 00 00 ff ff 00 00 00 ff ff
0000100 00 34 00 cb ff 42 e8 21 5e 0f 00 00 00 ff ff 0a
0000110 f0 66 64 12 61 c0 15 dc e8 a0 48 bf 48 af 2a b3
0000120 20 c0 9b 95 0d c4 67 04 42 53 06 06 06 40 00 06
0000130 00 f9 ff 6d 01 00 00 00 00 42 e8 21 5e 0f 00 00
0000140 00 ff ff 0a f0 66 64 12 61 c0 15 dc e8 a0 48 bf
0000150 48 af 2a b3 20 c0 9b 95 0d c4 67 04 42 53 06 06
0000160 06 40 00 06 00 f9 ff 6d 01 00 00 00 00 50 4b 01

			p.errorf("rhs of shift must be integer: %s", str)
		} else {
			r2, ok := p.registerReference(str)
			if !ok {
				p.errorf("rhs of shift must be register or integer: %s", str)
			}
			count = (r2&15)<<8 | 1<<4
		}
	case scanner.Int, '(':
		p.back()
		x := int64(p.expr())
		if p.arch.Family == sys.ARM64 {
			if x >= 64 {
				p.errorf("register shift count too large: %s", str)
			}

	{"$main(SB)", "$main(SB)"},
	{"$masks<>(SB)", "$masks<>(SB)"},
	{"$setg_gcc<>(SB)", "$setg_gcc<>(SB)"},
	{"$shifts<>(SB)", "$shifts<>(SB)"},
	{"$~(1<<63)", "$9223372036854775807"},
	{"$~0x3F", "$-64"},
	{"$~15", "$-16"},
	{"(((8)&0xf)*4)(SP)", "32(SP)"},
	{"(((8-14)&0xf)*4)(SP)", "40(SP)"},
	{"(6+8)(AX)", "14(AX)"},
	{"(8*4)(BP)", "32(BP)"},
	{"(AX)", "(AX)"},
	{"(AX)(CX*8)", "(AX)(CX*8)"},