disas/libvixl/vixl/a64/decoder-a64.h

   1 // Copyright 2014, ARM Limited
   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_A64_DECODER_A64_H_
  28 #define VIXL_A64_DECODER_A64_H_
  29
  30 #include <list>
  31
  32 #include "vixl/globals.h"
  33 #include "vixl/a64/instructions-a64.h"
  34
  35
  36 // List macro containing all visitors needed by the decoder class.
  37
  38 #define VISITOR_LIST_THAT_RETURN(V) \
  39   V(PCRelAddressing)                \
  40   V(AddSubImmediate)                \
  41   V(LogicalImmediate)               \
  42   V(MoveWideImmediate)              \
  43   V(Bitfield)                       \
  44   V(Extract)                        \
  45   V(UnconditionalBranch)            \
  46   V(UnconditionalBranchToRegister)  \
  47   V(CompareBranch)                  \
  48   V(TestBranch)                     \
  49   V(ConditionalBranch)              \
  50   V(System)                         \
  51   V(Exception)                      \
  52   V(LoadStorePairPostIndex)         \
  53   V(LoadStorePairOffset)            \
  54   V(LoadStorePairPreIndex)          \
  55   V(LoadStorePairNonTemporal)       \
  56   V(LoadLiteral)                    \
  57   V(LoadStoreUnscaledOffset)        \
  58   V(LoadStorePostIndex)             \
  59   V(LoadStorePreIndex)              \
  60   V(LoadStoreRegisterOffset)        \
  61   V(LoadStoreUnsignedOffset)        \
  62   V(LoadStoreExclusive)             \
  63   V(LogicalShifted)                 \
  64   V(AddSubShifted)                  \
  65   V(AddSubExtended)                 \
  66   V(AddSubWithCarry)                \
  67   V(ConditionalCompareRegister)     \
  68   V(ConditionalCompareImmediate)    \
  69   V(ConditionalSelect)              \
  70   V(DataProcessing1Source)          \
  71   V(DataProcessing2Source)          \
  72   V(DataProcessing3Source)          \
  73   V(FPCompare)                      \
  74   V(FPConditionalCompare)           \
  75   V(FPConditionalSelect)            \
  76   V(FPImmediate)                    \
  77   V(FPDataProcessing1Source)        \
  78   V(FPDataProcessing2Source)        \
  79   V(FPDataProcessing3Source)        \
  80   V(FPIntegerConvert)               \
  81   V(FPFixedPointConvert)            \
  82   V(Crypto2RegSHA)                  \
  83   V(Crypto3RegSHA)                  \
  84   V(CryptoAES)                      \
  85   V(NEON2RegMisc)                   \
  86   V(NEON3Different)                 \
  87   V(NEON3Same)                      \
  88   V(NEONAcrossLanes)                \
  89   V(NEONByIndexedElement)           \
  90   V(NEONCopy)                       \
  91   V(NEONExtract)                    \
  92   V(NEONLoadStoreMultiStruct)       \
  93   V(NEONLoadStoreMultiStructPostIndex)  \
  94   V(NEONLoadStoreSingleStruct)      \
  95   V(NEONLoadStoreSingleStructPostIndex) \
  96   V(NEONModifiedImmediate)          \
  97   V(NEONScalar2RegMisc)             \
  98   V(NEONScalar3Diff)                \
  99   V(NEONScalar3Same)                \
 100   V(NEONScalarByIndexedElement)     \
 101   V(NEONScalarCopy)                 \
 102   V(NEONScalarPairwise)             \
 103   V(NEONScalarShiftImmediate)       \
 104   V(NEONShiftImmediate)             \
 105   V(NEONTable)                      \
 106   V(NEONPerm)                       \
 107
 108 #define VISITOR_LIST_THAT_DONT_RETURN(V)  \
 109   V(Unallocated)                          \
 110   V(Unimplemented)                        \
 111
 112 #define VISITOR_LIST(V)             \
 113   VISITOR_LIST_THAT_RETURN(V)       \
 114   VISITOR_LIST_THAT_DONT_RETURN(V)  \
 115
 116 namespace vixl {
 117
 118 // The Visitor interface. Disassembler and simulator (and other tools)
 119 // must provide implementations for all of these functions.
 120 class DecoderVisitor {
 121  public:
 122   enum VisitorConstness {
 123     kConstVisitor,
 124     kNonConstVisitor
 125   };
 126   explicit DecoderVisitor(VisitorConstness constness = kConstVisitor)
 127       : constness_(constness) {}
 128
 129   virtual ~DecoderVisitor() {}
 130
 131   #define DECLARE(A) virtual void Visit##A(const Instruction* instr) = 0;
 132   VISITOR_LIST(DECLARE)
 133   #undef DECLARE
 134
 135   bool IsConstVisitor() const { return constness_ == kConstVisitor; }
 136   Instruction* MutableInstruction(const Instruction* instr) {
 137     VIXL_ASSERT(!IsConstVisitor());
 138     return const_cast<Instruction*>(instr);
 139   }
 140
 141  private:
 142   const VisitorConstness constness_;
 143 };
 144
 145
 146 class Decoder {
 147  public:
 148   Decoder() {}
 149
 150   // Top-level wrappers around the actual decoding function.
 151   void Decode(const Instruction* instr) {
 152     std::list<DecoderVisitor*>::iterator it;
 153     for (it = visitors_.begin(); it != visitors_.end(); it++) {
 154       VIXL_ASSERT((*it)->IsConstVisitor());
 155     }
 156     DecodeInstruction(instr);
 157   }
 158   void Decode(Instruction* instr) {
 159     DecodeInstruction(const_cast<const Instruction*>(instr));
 160   }
 161
 162   // Register a new visitor class with the decoder.
 163   // Decode() will call the corresponding visitor method from all registered
 164   // visitor classes when decoding reaches the leaf node of the instruction
 165   // decode tree.
 166   // Visitors are called in order.
 167   // A visitor can be registered multiple times.
 168   //
 169   //   d.AppendVisitor(V1);
 170   //   d.AppendVisitor(V2);
 171   //   d.PrependVisitor(V2);
 172   //   d.AppendVisitor(V3);
 173   //
 174   //   d.Decode(i);
 175   //
 176   // will call in order visitor methods in V2, V1, V2, V3.
 177   void AppendVisitor(DecoderVisitor* visitor);
 178   void PrependVisitor(DecoderVisitor* visitor);
 179   // These helpers register `new_visitor` before or after the first instance of
 180   // `registered_visiter` in the list.
 181   // So if
 182   //   V1, V2, V1, V2
 183   // are registered in this order in the decoder, calls to
 184   //   d.InsertVisitorAfter(V3, V1);
 185   //   d.InsertVisitorBefore(V4, V2);
 186   // will yield the order
 187   //   V1, V3, V4, V2, V1, V2
 188   //
 189   // For more complex modifications of the order of registered visitors, one can
 190   // directly access and modify the list of visitors via the `visitors()'
 191   // accessor.
 192   void InsertVisitorBefore(DecoderVisitor* new_visitor,
 193                            DecoderVisitor* registered_visitor);
 194   void InsertVisitorAfter(DecoderVisitor* new_visitor,
 195                           DecoderVisitor* registered_visitor);
 196
 197   // Remove all instances of a previously registered visitor class from the list
 198   // of visitors stored by the decoder.
 199   void RemoveVisitor(DecoderVisitor* visitor);
 200
 201   #define DECLARE(A) void Visit##A(const Instruction* instr);
 202   VISITOR_LIST(DECLARE)
 203   #undef DECLARE
 204
 205
 206   std::list<DecoderVisitor*>* visitors() { return &visitors_; }
 207
 208  private:
 209   // Decodes an instruction and calls the visitor functions registered with the
 210   // Decoder class.
 211   void DecodeInstruction(const Instruction* instr);
 212
 213   // Decode the PC relative addressing instruction, and call the corresponding
 214   // visitors.
 215   // On entry, instruction bits 27:24 = 0x0.
 216   void DecodePCRelAddressing(const Instruction* instr);
 217
 218   // Decode the add/subtract immediate instruction, and call the correspoding
 219   // visitors.
 220   // On entry, instruction bits 27:24 = 0x1.
 221   void DecodeAddSubImmediate(const Instruction* instr);
 222
 223   // Decode the branch, system command, and exception generation parts of
 224   // the instruction tree, and call the corresponding visitors.
 225   // On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
 226   void DecodeBranchSystemException(const Instruction* instr);
 227
 228   // Decode the load and store parts of the instruction tree, and call
 229   // the corresponding visitors.
 230   // On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
 231   void DecodeLoadStore(const Instruction* instr);
 232
 233   // Decode the logical immediate and move wide immediate parts of the
 234   // instruction tree, and call the corresponding visitors.
 235   // On entry, instruction bits 27:24 = 0x2.
 236   void DecodeLogical(const Instruction* instr);
 237
 238   // Decode the bitfield and extraction parts of the instruction tree,
 239   // and call the corresponding visitors.
 240   // On entry, instruction bits 27:24 = 0x3.
 241   void DecodeBitfieldExtract(const Instruction* instr);
 242
 243   // Decode the data processing parts of the instruction tree, and call the
 244   // corresponding visitors.
 245   // On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
 246   void DecodeDataProcessing(const Instruction* instr);
 247
 248   // Decode the floating point parts of the instruction tree, and call the
 249   // corresponding visitors.
 250   // On entry, instruction bits 27:24 = {0xE, 0xF}.
 251   void DecodeFP(const Instruction* instr);
 252
 253   // Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
 254   // and call the corresponding visitors.
 255   // On entry, instruction bits 29:25 = 0x6.
 256   void DecodeNEONLoadStore(const Instruction* instr);
 257
 258   // Decode the Advanced SIMD (NEON) vector data processing part of the
 259   // instruction tree, and call the corresponding visitors.
 260   // On entry, instruction bits 28:25 = 0x7.
 261   void DecodeNEONVectorDataProcessing(const Instruction* instr);
 262
 263   // Decode the Advanced SIMD (NEON) scalar data processing part of the
 264   // instruction tree, and call the corresponding visitors.
 265   // On entry, instruction bits 28:25 = 0xF.
 266   void DecodeNEONScalarDataProcessing(const Instruction* instr);
 267
 268  private:
 269   // Visitors are registered in a list.
 270   std::list<DecoderVisitor*> visitors_;
 271 };
 272
 273 }  // namespace vixl
 274
 275 #endif  // VIXL_A64_DECODER_A64_H_