r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            26,
			want:         26,
			wantBuffered: 0,
		},
		{
			name:         "discard more than end",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			n:            27,
			want:         26,
			wantErr:      io.EOF,
			wantBuffered: 0,
		},

0000320 bb fc 6c d6 99 23 eb 36 ad c6 c5 e1 d8 e1 e2 3e
0000330 d9 90 5a f7 91 5d 6f bc 33 6d 98 47 d2 7c 2e 2f
0000340 99 a4 25 72 85 49 2c be 0b 5b af 8f e5 6e 81 a6
0000350 a3 5a 6f 39 53 3a ab 7a 8b 1e 26 f7 46 6c 7d 26
0000360 53 b3 22 31 94 d3 83 f2 18 4d f5 92 33 27 53 97
0000370 0f d3 e6 55 9c a6 c5 31 87 6f d3 f3 ae 39 6f 56
0000380 10 7b ab 7e d0 b4 ca f2 b8 05 be 3f 0e 6e 5a 75

}

// User-defined self-inverse mapping function
func rot13(r rune) rune {
	const step = 13
	if r >= 'a' && r <= 'z' {
		return ((r - 'a' + step) % 26) + 'a'
	}
	if r >= 'A' && r <= 'Z' {
		return ((r - 'A' + step) % 26) + 'A'
	}
	return r
}

func TestMap(t *testing.T) {
	// Run a couple of awful growth/shrinkage tests
	a := tenRunes('a')

// ADR
	ADR	next, R11     // ADR R11 // 2b000010
next:
	NOP
	ADR -2(PC), R10    // 0a000010
	ADR 2(PC), R16     // 10000010
	ADR -26(PC), R1    // 01000010
	ADR 12(PC), R2     // 02000010
	ADRP -2(PC), R10   // 0a000090
	ADRP 2(PC), R16    // 10000090
	ADRP -26(PC), R1   // 01000090
	ADRP 12(PC), R2    // 02000090

// LDP/STP
	LDP	(R0), (R0, R1)      // 000440a9
	LDP	(R0), (R1, R2)      // 010840a9