• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Copyright 2014, VIXL authors
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are met:
6 //
7 //   * Redistributions of source code must retain the above copyright notice,
8 //     this list of conditions and the following disclaimer.
9 //   * Redistributions in binary form must reproduce the above copyright notice,
10 //     this list of conditions and the following disclaimer in the documentation
11 //     and/or other materials provided with the distribution.
12 //   * Neither the name of ARM Limited nor the names of its contributors may be
13 //     used to endorse or promote products derived from this software without
14 //     specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
17 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
20 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 
27 #ifndef VIXL_AARCH64_DECODER_AARCH64_H_
28 #define VIXL_AARCH64_DECODER_AARCH64_H_
29 
30 #include <list>
31 
32 #include "../globals-vixl.h"
33 
34 #include "instructions-aarch64.h"
35 
36 
37 // List macro containing all visitors needed by the decoder class.
38 
39 #define VISITOR_LIST_THAT_RETURN(V)     \
40   V(PCRelAddressing)                    \
41   V(AddSubImmediate)                    \
42   V(LogicalImmediate)                   \
43   V(MoveWideImmediate)                  \
44   V(Bitfield)                           \
45   V(Extract)                            \
46   V(UnconditionalBranch)                \
47   V(UnconditionalBranchToRegister)      \
48   V(CompareBranch)                      \
49   V(TestBranch)                         \
50   V(ConditionalBranch)                  \
51   V(System)                             \
52   V(Exception)                          \
53   V(LoadStorePairPostIndex)             \
54   V(LoadStorePairOffset)                \
55   V(LoadStorePairPreIndex)              \
56   V(LoadStorePairNonTemporal)           \
57   V(LoadLiteral)                        \
58   V(LoadStoreUnscaledOffset)            \
59   V(LoadStorePostIndex)                 \
60   V(LoadStorePreIndex)                  \
61   V(LoadStoreRegisterOffset)            \
62   V(LoadStoreUnsignedOffset)            \
63   V(LoadStoreExclusive)                 \
64   V(LogicalShifted)                     \
65   V(AddSubShifted)                      \
66   V(AddSubExtended)                     \
67   V(AddSubWithCarry)                    \
68   V(ConditionalCompareRegister)         \
69   V(ConditionalCompareImmediate)        \
70   V(ConditionalSelect)                  \
71   V(DataProcessing1Source)              \
72   V(DataProcessing2Source)              \
73   V(DataProcessing3Source)              \
74   V(FPCompare)                          \
75   V(FPConditionalCompare)               \
76   V(FPConditionalSelect)                \
77   V(FPImmediate)                        \
78   V(FPDataProcessing1Source)            \
79   V(FPDataProcessing2Source)            \
80   V(FPDataProcessing3Source)            \
81   V(FPIntegerConvert)                   \
82   V(FPFixedPointConvert)                \
83   V(Crypto2RegSHA)                      \
84   V(Crypto3RegSHA)                      \
85   V(CryptoAES)                          \
86   V(NEON2RegMisc)                       \
87   V(NEON3Different)                     \
88   V(NEON3Same)                          \
89   V(NEONAcrossLanes)                    \
90   V(NEONByIndexedElement)               \
91   V(NEONCopy)                           \
92   V(NEONExtract)                        \
93   V(NEONLoadStoreMultiStruct)           \
94   V(NEONLoadStoreMultiStructPostIndex)  \
95   V(NEONLoadStoreSingleStruct)          \
96   V(NEONLoadStoreSingleStructPostIndex) \
97   V(NEONModifiedImmediate)              \
98   V(NEONScalar2RegMisc)                 \
99   V(NEONScalar3Diff)                    \
100   V(NEONScalar3Same)                    \
101   V(NEONScalarByIndexedElement)         \
102   V(NEONScalarCopy)                     \
103   V(NEONScalarPairwise)                 \
104   V(NEONScalarShiftImmediate)           \
105   V(NEONShiftImmediate)                 \
106   V(NEONTable)                          \
107   V(NEONPerm)
108 
109 #define VISITOR_LIST_THAT_DONT_RETURN(V) \
110   V(Unallocated)                         \
111   V(Unimplemented)
112 
113 #define VISITOR_LIST(V)       \
114   VISITOR_LIST_THAT_RETURN(V) \
115   VISITOR_LIST_THAT_DONT_RETURN(V)
116 
117 namespace vixl {
118 namespace aarch64 {
119 
120 // The Visitor interface. Disassembler and simulator (and other tools)
121 // must provide implementations for all of these functions.
122 class DecoderVisitor {
123  public:
124   enum VisitorConstness { kConstVisitor, kNonConstVisitor };
125   explicit DecoderVisitor(VisitorConstness constness = kConstVisitor)
constness_(constness)126       : constness_(constness) {}
127 
~DecoderVisitor()128   virtual ~DecoderVisitor() {}
129 
130 #define DECLARE(A) virtual void Visit##A(const Instruction* instr) = 0;
VISITOR_LIST(DECLARE)131   VISITOR_LIST(DECLARE)
132 #undef DECLARE
133 
134   bool IsConstVisitor() const { return constness_ == kConstVisitor; }
MutableInstruction(const Instruction * instr)135   Instruction* MutableInstruction(const Instruction* instr) {
136     VIXL_ASSERT(!IsConstVisitor());
137     return const_cast<Instruction*>(instr);
138   }
139 
140  private:
141   const VisitorConstness constness_;
142 };
143 
144 
145 class Decoder {
146  public:
Decoder()147   Decoder() {}
148 
149   // Top-level wrappers around the actual decoding function.
Decode(const Instruction * instr)150   void Decode(const Instruction* instr) {
151     std::list<DecoderVisitor*>::iterator it;
152     for (it = visitors_.begin(); it != visitors_.end(); it++) {
153       VIXL_ASSERT((*it)->IsConstVisitor());
154     }
155     DecodeInstruction(instr);
156   }
Decode(Instruction * instr)157   void Decode(Instruction* instr) {
158     DecodeInstruction(const_cast<const Instruction*>(instr));
159   }
160 
161   // Register a new visitor class with the decoder.
162   // Decode() will call the corresponding visitor method from all registered
163   // visitor classes when decoding reaches the leaf node of the instruction
164   // decode tree.
165   // Visitors are called in order.
166   // A visitor can be registered multiple times.
167   //
168   //   d.AppendVisitor(V1);
169   //   d.AppendVisitor(V2);
170   //   d.PrependVisitor(V2);
171   //   d.AppendVisitor(V3);
172   //
173   //   d.Decode(i);
174   //
175   // will call in order visitor methods in V2, V1, V2, V3.
176   void AppendVisitor(DecoderVisitor* visitor);
177   void PrependVisitor(DecoderVisitor* visitor);
178   // These helpers register `new_visitor` before or after the first instance of
179   // `registered_visiter` in the list.
180   // So if
181   //   V1, V2, V1, V2
182   // are registered in this order in the decoder, calls to
183   //   d.InsertVisitorAfter(V3, V1);
184   //   d.InsertVisitorBefore(V4, V2);
185   // will yield the order
186   //   V1, V3, V4, V2, V1, V2
187   //
188   // For more complex modifications of the order of registered visitors, one can
189   // directly access and modify the list of visitors via the `visitors()'
190   // accessor.
191   void InsertVisitorBefore(DecoderVisitor* new_visitor,
192                            DecoderVisitor* registered_visitor);
193   void InsertVisitorAfter(DecoderVisitor* new_visitor,
194                           DecoderVisitor* registered_visitor);
195 
196   // Remove all instances of a previously registered visitor class from the list
197   // of visitors stored by the decoder.
198   void RemoveVisitor(DecoderVisitor* visitor);
199 
200 #define DECLARE(A) void Visit##A(const Instruction* instr);
VISITOR_LIST(DECLARE)201   VISITOR_LIST(DECLARE)
202 #undef DECLARE
203 
204 
205   std::list<DecoderVisitor*>* visitors() { return &visitors_; }
206 
207  private:
208   // Decodes an instruction and calls the visitor functions registered with the
209   // Decoder class.
210   void DecodeInstruction(const Instruction* instr);
211 
212   // Decode the PC relative addressing instruction, and call the corresponding
213   // visitors.
214   // On entry, instruction bits 27:24 = 0x0.
215   void DecodePCRelAddressing(const Instruction* instr);
216 
217   // Decode the add/subtract immediate instruction, and call the correspoding
218   // visitors.
219   // On entry, instruction bits 27:24 = 0x1.
220   void DecodeAddSubImmediate(const Instruction* instr);
221 
222   // Decode the branch, system command, and exception generation parts of
223   // the instruction tree, and call the corresponding visitors.
224   // On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
225   void DecodeBranchSystemException(const Instruction* instr);
226 
227   // Decode the load and store parts of the instruction tree, and call
228   // the corresponding visitors.
229   // On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
230   void DecodeLoadStore(const Instruction* instr);
231 
232   // Decode the logical immediate and move wide immediate parts of the
233   // instruction tree, and call the corresponding visitors.
234   // On entry, instruction bits 27:24 = 0x2.
235   void DecodeLogical(const Instruction* instr);
236 
237   // Decode the bitfield and extraction parts of the instruction tree,
238   // and call the corresponding visitors.
239   // On entry, instruction bits 27:24 = 0x3.
240   void DecodeBitfieldExtract(const Instruction* instr);
241 
242   // Decode the data processing parts of the instruction tree, and call the
243   // corresponding visitors.
244   // On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
245   void DecodeDataProcessing(const Instruction* instr);
246 
247   // Decode the floating point parts of the instruction tree, and call the
248   // corresponding visitors.
249   // On entry, instruction bits 27:24 = {0xE, 0xF}.
250   void DecodeFP(const Instruction* instr);
251 
252   // Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
253   // and call the corresponding visitors.
254   // On entry, instruction bits 29:25 = 0x6.
255   void DecodeNEONLoadStore(const Instruction* instr);
256 
257   // Decode the Advanced SIMD (NEON) vector data processing part of the
258   // instruction tree, and call the corresponding visitors.
259   // On entry, instruction bits 28:25 = 0x7.
260   void DecodeNEONVectorDataProcessing(const Instruction* instr);
261 
262   // Decode the Advanced SIMD (NEON) scalar data processing part of the
263   // instruction tree, and call the corresponding visitors.
264   // On entry, instruction bits 28:25 = 0xF.
265   void DecodeNEONScalarDataProcessing(const Instruction* instr);
266 
267  private:
268   // Visitors are registered in a list.
269   std::list<DecoderVisitor*> visitors_;
270 };
271 
272 }  // namespace aarch64
273 }  // namespace vixl
274 
275 #endif  // VIXL_AARCH64_DECODER_AARCH64_H_
276