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
|
// Copyright 2015 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.
package ssa
import (
"cmd/compile/internal/types"
"testing"
)
func TestDeadStore(t *testing.T) {
c := testConfig(t)
ptrType := c.config.Types.BytePtr
t.Logf("PTRTYPE %v", ptrType)
fun := c.Fun("entry",
Bloc("entry",
Valu("start", OpInitMem, types.TypeMem, 0, nil),
Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
Valu("v", OpConstBool, c.config.Types.Bool, 1, nil),
Valu("addr1", OpAddr, ptrType, 0, nil, "sb"),
Valu("addr2", OpAddr, ptrType, 0, nil, "sb"),
Valu("addr3", OpAddr, ptrType, 0, nil, "sb"),
Valu("zero1", OpZero, types.TypeMem, 1, c.config.Types.Bool, "addr3", "start"),
Valu("store1", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "zero1"),
Valu("store2", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr2", "v", "store1"),
Valu("store3", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "store2"),
Valu("store4", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr3", "v", "store3"),
Goto("exit")),
Bloc("exit",
Exit("store3")))
CheckFunc(fun.f)
dse(fun.f)
CheckFunc(fun.f)
v1 := fun.values["store1"]
if v1.Op != OpCopy {
t.Errorf("dead store not removed")
}
v2 := fun.values["zero1"]
if v2.Op != OpCopy {
t.Errorf("dead store (zero) not removed")
}
}
func TestDeadStorePhi(t *testing.T) {
// make sure we don't get into an infinite loop with phi values.
c := testConfig(t)
ptrType := c.config.Types.BytePtr
fun := c.Fun("entry",
Bloc("entry",
Valu("start", OpInitMem, types.TypeMem, 0, nil),
Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
Valu("v", OpConstBool, c.config.Types.Bool, 1, nil),
Valu("addr", OpAddr, ptrType, 0, nil, "sb"),
Goto("loop")),
Bloc("loop",
Valu("phi", OpPhi, types.TypeMem, 0, nil, "start", "store"),
Valu("store", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr", "v", "phi"),
If("v", "loop", "exit")),
Bloc("exit",
Exit("store")))
CheckFunc(fun.f)
dse(fun.f)
CheckFunc(fun.f)
}
func TestDeadStoreTypes(t *testing.T) {
// Make sure a narrow store can't shadow a wider one. We test an even
// stronger restriction, that one store can't shadow another unless the
// types of the address fields are identical (where identicalness is
// decided by the CSE pass).
c := testConfig(t)
t1 := c.config.Types.UInt64.PtrTo()
t2 := c.config.Types.UInt32.PtrTo()
fun := c.Fun("entry",
Bloc("entry",
Valu("start", OpInitMem, types.TypeMem, 0, nil),
Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
Valu("v", OpConstBool, c.config.Types.Bool, 1, nil),
Valu("addr1", OpAddr, t1, 0, nil, "sb"),
Valu("addr2", OpAddr, t2, 0, nil, "sb"),
Valu("store1", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "start"),
Valu("store2", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr2", "v", "store1"),
Goto("exit")),
Bloc("exit",
Exit("store2")))
CheckFunc(fun.f)
cse(fun.f)
dse(fun.f)
CheckFunc(fun.f)
v := fun.values["store1"]
if v.Op == OpCopy {
t.Errorf("store %s incorrectly removed", v)
}
}
func TestDeadStoreUnsafe(t *testing.T) {
// Make sure a narrow store can't shadow a wider one. The test above
// covers the case of two different types, but unsafe pointer casting
// can get to a point where the size is changed but type unchanged.
c := testConfig(t)
ptrType := c.config.Types.UInt64.PtrTo()
fun := c.Fun("entry",
Bloc("entry",
Valu("start", OpInitMem, types.TypeMem, 0, nil),
Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
Valu("v", OpConstBool, c.config.Types.Bool, 1, nil),
Valu("addr1", OpAddr, ptrType, 0, nil, "sb"),
Valu("store1", OpStore, types.TypeMem, 0, c.config.Types.Int64, "addr1", "v", "start"), // store 8 bytes
Valu("store2", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "store1"), // store 1 byte
Goto("exit")),
Bloc("exit",
Exit("store2")))
CheckFunc(fun.f)
cse(fun.f)
dse(fun.f)
CheckFunc(fun.f)
v := fun.values["store1"]
if v.Op == OpCopy {
t.Errorf("store %s incorrectly removed", v)
}
}
|
