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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
// Copyright 2013, ARM Limited
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of ARM Limited nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef VIXL_A64_DECODER_A64_H_
#define VIXL_A64_DECODER_A64_H_
#include <list>
#include "globals.h"
#include "a64/instructions-a64.h"
// List macro containing all visitors needed by the decoder class.
#define VISITOR_LIST(V) \
V(PCRelAddressing) \
V(AddSubImmediate) \
V(LogicalImmediate) \
V(MoveWideImmediate) \
V(Bitfield) \
V(Extract) \
V(UnconditionalBranch) \
V(UnconditionalBranchToRegister) \
V(CompareBranch) \
V(TestBranch) \
V(ConditionalBranch) \
V(System) \
V(Exception) \
V(LoadStorePairPostIndex) \
V(LoadStorePairOffset) \
V(LoadStorePairPreIndex) \
V(LoadStorePairNonTemporal) \
V(LoadLiteral) \
V(LoadStoreUnscaledOffset) \
V(LoadStorePostIndex) \
V(LoadStorePreIndex) \
V(LoadStoreRegisterOffset) \
V(LoadStoreUnsignedOffset) \
V(LoadStoreExclusive) \
V(LogicalShifted) \
V(AddSubShifted) \
V(AddSubExtended) \
V(AddSubWithCarry) \
V(ConditionalCompareRegister) \
V(ConditionalCompareImmediate) \
V(ConditionalSelect) \
V(DataProcessing1Source) \
V(DataProcessing2Source) \
V(DataProcessing3Source) \
V(FPCompare) \
V(FPConditionalCompare) \
V(FPConditionalSelect) \
V(FPImmediate) \
V(FPDataProcessing1Source) \
V(FPDataProcessing2Source) \
V(FPDataProcessing3Source) \
V(FPIntegerConvert) \
V(FPFixedPointConvert) \
V(Unallocated) \
V(Unimplemented)
namespace vixl {
// The Visitor interface. Disassembler and simulator (and other tools)
// must provide implementations for all of these functions.
class DecoderVisitor {
public:
enum VisitorConstness {
kConstVisitor,
kNonConstVisitor
};
explicit DecoderVisitor(VisitorConstness constness = kConstVisitor)
: constness_(constness) {}
virtual ~DecoderVisitor() {}
#define DECLARE(A) virtual void Visit##A(const Instruction* instr) = 0;
VISITOR_LIST(DECLARE)
#undef DECLARE
bool IsConstVisitor() const { return constness_ == kConstVisitor; }
Instruction* MutableInstruction(const Instruction* instr) {
VIXL_ASSERT(!IsConstVisitor());
return const_cast<Instruction*>(instr);
}
private:
const VisitorConstness constness_;
};
class Decoder {
public:
Decoder() {}
// Top-level wrappers around the actual decoding function.
void Decode(const Instruction* instr) {
std::list<DecoderVisitor*>::iterator it;
for (it = visitors_.begin(); it != visitors_.end(); it++) {
VIXL_ASSERT((*it)->IsConstVisitor());
}
DecodeInstruction(instr);
}
void Decode(Instruction* instr) {
DecodeInstruction(const_cast<const Instruction*>(instr));
}
// Register a new visitor class with the decoder.
// Decode() will call the corresponding visitor method from all registered
// visitor classes when decoding reaches the leaf node of the instruction
// decode tree.
// Visitors are called in order.
// A visitor can be registered multiple times.
//
// d.AppendVisitor(V1);
// d.AppendVisitor(V2);
// d.PrependVisitor(V2);
// d.AppendVisitor(V3);
//
// d.Decode(i);
//
// will call in order visitor methods in V2, V1, V2, V3.
void AppendVisitor(DecoderVisitor* visitor);
void PrependVisitor(DecoderVisitor* visitor);
// These helpers register `new_visitor` before or after the first instance of
// `registered_visiter` in the list.
// So if
// V1, V2, V1, V2
// are registered in this order in the decoder, calls to
// d.InsertVisitorAfter(V3, V1);
// d.InsertVisitorBefore(V4, V2);
// will yield the order
// V1, V3, V4, V2, V1, V2
//
// For more complex modifications of the order of registered visitors, one can
// directly access and modify the list of visitors via the `visitors()'
// accessor.
void InsertVisitorBefore(DecoderVisitor* new_visitor,
DecoderVisitor* registered_visitor);
void InsertVisitorAfter(DecoderVisitor* new_visitor,
DecoderVisitor* registered_visitor);
// Remove all instances of a previously registered visitor class from the list
// of visitors stored by the decoder.
void RemoveVisitor(DecoderVisitor* visitor);
#define DECLARE(A) void Visit##A(const Instruction* instr);
VISITOR_LIST(DECLARE)
#undef DECLARE
std::list<DecoderVisitor*>* visitors() { return &visitors_; }
private:
// Decodes an instruction and calls the visitor functions registered with the
// Decoder class.
void DecodeInstruction(const Instruction* instr);
// Decode the PC relative addressing instruction, and call the corresponding
// visitors.
// On entry, instruction bits 27:24 = 0x0.
void DecodePCRelAddressing(const Instruction* instr);
// Decode the add/subtract immediate instruction, and call the correspoding
// visitors.
// On entry, instruction bits 27:24 = 0x1.
void DecodeAddSubImmediate(const Instruction* instr);
// Decode the branch, system command, and exception generation parts of
// the instruction tree, and call the corresponding visitors.
// On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
void DecodeBranchSystemException(const Instruction* instr);
// Decode the load and store parts of the instruction tree, and call
// the corresponding visitors.
// On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
void DecodeLoadStore(const Instruction* instr);
// Decode the logical immediate and move wide immediate parts of the
// instruction tree, and call the corresponding visitors.
// On entry, instruction bits 27:24 = 0x2.
void DecodeLogical(const Instruction* instr);
// Decode the bitfield and extraction parts of the instruction tree,
// and call the corresponding visitors.
// On entry, instruction bits 27:24 = 0x3.
void DecodeBitfieldExtract(const Instruction* instr);
// Decode the data processing parts of the instruction tree, and call the
// corresponding visitors.
// On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
void DecodeDataProcessing(const Instruction* instr);
// Decode the floating point parts of the instruction tree, and call the
// corresponding visitors.
// On entry, instruction bits 27:24 = {0xE, 0xF}.
void DecodeFP(const Instruction* instr);
// Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
// and call the corresponding visitors.
// On entry, instruction bits 29:25 = 0x6.
void DecodeAdvSIMDLoadStore(const Instruction* instr);
// Decode the Advanced SIMD (NEON) data processing part of the instruction
// tree, and call the corresponding visitors.
// On entry, instruction bits 27:25 = 0x7.
void DecodeAdvSIMDDataProcessing(const Instruction* instr);
private:
// Visitors are registered in a list.
std::list<DecoderVisitor*> visitors_;
};
} // namespace vixl
#endif // VIXL_A64_DECODER_A64_H_
|
