summaryrefslogtreecommitdiff
path: root/test/rotate.go
blob: aa334b4218c42887775521708e94aac33f8f525a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
// $G $D/$F.go && $L $F.$A &&
// ./$A.out >tmp.go && $G tmp.go && $L -o $A.out1 tmp.$A && ./$A.out1
// rm -f tmp.go $A.out1

// NOTE: This test is not run by 'run.go' and so not run by all.bash.
// To run this test you must use the ./run shell script.

// Copyright 2012 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Generate test of shift and rotate by constants.
// The output is compiled and run.
//
// The output takes around a gigabyte of memory to compile, link, and run
// but it is only done during ./run, not in normal builds using run.go.

package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"strings"
)

func main() {
	flag.Parse()

	b := bufio.NewWriter(os.Stdout)
	defer b.Flush()

	fmt.Fprintf(b, "%s\n", prolog)

	for logBits := uint(3); logBits <= 6; logBits++ {
		typ := fmt.Sprintf("int%d", 1<<logBits)
		fmt.Fprint(b, strings.Replace(checkFunc, "XXX", typ, -1))
		fmt.Fprint(b, strings.Replace(checkFunc, "XXX", "u"+typ, -1))
		for mode := 0; mode < 1<<2; mode++ {
			gentest(b, 1<<logBits, mode&1 != 0, mode&2 != 0)
		}
	}
}

const prolog = `

package main

import (
	"fmt"
	"os"
)

var (
	i8 int8 = 0x12
	i16 int16 = 0x1234
	i32 int32 = 0x12345678
	i64 int64 = 0x123456789abcdef0
	ui8 uint8 = 0x12
	ui16 uint16 = 0x1234
	ui32 uint32 = 0x12345678
	ui64 uint64 = 0x123456789abcdef0

	ni8 = ^i8
	ni16 = ^i16
	ni32 = ^i32
	ni64 = ^i64
	nui8 = ^ui8
	nui16 = ^ui16
	nui32 = ^ui32
	nui64 = ^ui64
)

var nfail = 0

func main() {
	if nfail > 0 {
		fmt.Printf("BUG\n")
	}
}

`

const checkFunc = `
func check_XXX(desc string, have, want XXX) {
	if have != want {
		nfail++
		fmt.Printf("%s = %T(%#x), want %T(%#x)\n", desc, have, have, want, want)
		if nfail >= 100 {
			fmt.Printf("BUG: stopping after 100 failures\n")
			os.Exit(0)
		}
	}
}
`

var (
	uop = [2]func(x, y uint64) uint64{
		func(x, y uint64) uint64 {
			return x | y
		},
		func(x, y uint64) uint64 {
			return x ^ y
		},
	}
	iop = [2]func(x, y int64) int64{
		func(x, y int64) int64 {
			return x | y
		},
		func(x, y int64) int64 {
			return x ^ y
		},
	}
	cop = [2]byte{'|', '^'}
)

func gentest(b *bufio.Writer, bits uint, unsigned, inverted bool) {
	fmt.Fprintf(b, "func init() {\n")
	defer fmt.Fprintf(b, "}\n")
	n := 0

	// Generate tests for left/right and right/left.
	for l := uint(0); l <= bits; l++ {
		for r := uint(0); r <= bits; r++ {
			for o, op := range cop {
				typ := fmt.Sprintf("int%d", bits)
				v := fmt.Sprintf("i%d", bits)
				if unsigned {
					typ = "u" + typ
					v = "u" + v
				}
				v0 := int64(0x123456789abcdef0)
				if inverted {
					v = "n" + v
					v0 = ^v0
				}
				expr1 := fmt.Sprintf("%s<<%d %c %s>>%d", v, l, op, v, r)
				expr2 := fmt.Sprintf("%s>>%d %c %s<<%d", v, r, op, v, l)

				var result string
				if unsigned {
					v := uint64(v0) >> (64 - bits)
					v = uop[o](v<<l, v>>r)
					v <<= 64 - bits
					v >>= 64 - bits
					result = fmt.Sprintf("%#x", v)
				} else {
					v := int64(v0) >> (64 - bits)
					v = iop[o](v<<l, v>>r)
					v <<= 64 - bits
					v >>= 64 - bits
					result = fmt.Sprintf("%#x", v)
				}

				fmt.Fprintf(b, "\tcheck_%s(%q, %s, %s(%s))\n", typ, expr1, expr1, typ, result)
				fmt.Fprintf(b, "\tcheck_%s(%q, %s, %s(%s))\n", typ, expr2, expr2, typ, result)

				// Chop test into multiple functions so that there's not one
				// enormous function to compile/link.
				// All the functions are named init so we don't have to do
				// anything special to call them.  ☺
				if n++; n >= 50 {
					fmt.Fprintf(b, "}\n")
					fmt.Fprintf(b, "func init() {\n")
					n = 0
				}
			}
		}
	}
}