llvm/utils/TableGen/X86DisassemblerTables.h

   1 //===- X86DisassemblerTables.h - Disassembler tables ------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is part of the X86 Disassembler Emitter.
  10 // It contains the interface of the disassembler tables.
  11 // Documentation for the disassembler emitter in general can be found in
  12 //  X86DisassemblerEmitter.h.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #ifndef LLVM_UTILS_TABLEGEN_X86DISASSEMBLERTABLES_H
  17 #define LLVM_UTILS_TABLEGEN_X86DISASSEMBLERTABLES_H
  18
  19 #include "X86DisassemblerShared.h"
  20 #include "X86ModRMFilters.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 #include <map>
  23 #include <vector>
  24
  25 namespace llvm {
  26
  27 namespace X86Disassembler {
  28
  29 /// DisassemblerTables - Encapsulates all the decode tables being generated by
  30 ///   the table emitter.  Contains functions to populate the tables as well as
  31 ///   to emit them as hierarchical C structures suitable for consumption by the
  32 ///   runtime.
  33 class DisassemblerTables {
  34 private:
  35   /// The decoder tables.  There is one for each opcode type:
  36   /// [0] one-byte opcodes
  37   /// [1] two-byte opcodes of the form 0f __
  38   /// [2] three-byte opcodes of the form 0f 38 __
  39   /// [3] three-byte opcodes of the form 0f 3a __
  40   /// [4] XOP8 map opcode
  41   /// [5] XOP9 map opcode
  42   /// [6] XOPA map opcode
  43   /// [7] 3dnow map opcode
  44   /// [8] fixed length MAP5 opcode
  45   /// [9] fixed length MAP6 opcode
  46   std::unique_ptr<ContextDecision> Tables[10];
  47
  48   // Table of ModRM encodings.
  49   typedef std::map<std::vector<unsigned>, unsigned> ModRMMapTy;
  50   mutable ModRMMapTy ModRMTable;
  51
  52   /// The instruction information table
  53   std::vector<InstructionSpecifier> InstructionSpecifiers;
  54
  55   /// True if there are primary decode conflicts in the instruction set
  56   bool HasConflicts;
  57
  58   /// emitModRMDecision - Emits a table of entries corresponding to a single
  59   ///   ModR/M decision.  Compacts the ModR/M decision if possible.  ModR/M
  60   ///   decisions are printed as:
  61   ///
  62   ///   { /* struct ModRMDecision */
  63   ///     TYPE,
  64   ///     modRMTablennnn
  65   ///   }
  66   ///
  67   ///   where nnnn is a unique ID for the corresponding table of IDs.
  68   ///   TYPE indicates whether the table has one entry that is the same
  69   ///   regardless of ModR/M byte, two entries - one for bytes 0x00-0xbf and one
  70   ///   for bytes 0xc0-0xff -, or 256 entries, one for each possible byte.
  71   ///   nnnn is the number of a table for looking up these values.  The tables
  72   ///   are written separately so that tables consisting entirely of zeros will
  73   ///   not be duplicated.  (These all have the name modRMEmptyTable.)  A table
  74   ///   is printed as:
  75   ///
  76   ///   InstrUID modRMTablennnn[k] = {
  77   ///     nnnn, /* MNEMONIC */
  78   ///     ...
  79   ///     nnnn /* MNEMONIC */
  80   ///   };
  81   ///
  82   /// @param o1       - The output stream to print the ID table to.
  83   /// @param o2       - The output stream to print the decision structure to.
  84   /// @param i1       - The indentation level to use with stream o1.
  85   /// @param i2       - The indentation level to use with stream o2.
  86   /// @param ModRMTableNum - next table number for adding to ModRMTable.
  87   /// @param decision - The ModR/M decision to emit.  This decision has 256
  88   ///                   entries - emitModRMDecision decides how to compact it.
  89   void emitModRMDecision(raw_ostream &o1, raw_ostream &o2,
  90                          unsigned &i1, unsigned &i2, unsigned &ModRMTableNum,
  91                          ModRMDecision &decision) const;
  92
  93   /// emitOpcodeDecision - Emits an OpcodeDecision and all its subsidiary ModR/M
  94   ///   decisions.  An OpcodeDecision is printed as:
  95   ///
  96   ///   { /* struct OpcodeDecision */
  97   ///     /* 0x00 */
  98   ///     { /* struct ModRMDecision */
  99   ///       ...
 100   ///     }
 101   ///     ...
 102   ///   }
 103   ///
 104   ///   where the ModRMDecision structure is printed as described in the
 105   ///   documentation for emitModRMDecision().  emitOpcodeDecision() passes on a
 106   ///   stream and indent level for the UID tables generated by
 107   ///   emitModRMDecision(), but does not use them itself.
 108   ///
 109   /// @param o1       - The output stream to print the ID tables generated by
 110   ///                   emitModRMDecision() to.
 111   /// @param o2       - The output stream for the decision structure itself.
 112   /// @param i1       - The indent level to use with stream o1.
 113   /// @param i2       - The indent level to use with stream o2.
 114   /// @param ModRMTableNum - next table number for adding to ModRMTable.
 115   /// @param decision - The OpcodeDecision to emit along with its subsidiary
 116   ///                    structures.
 117   void emitOpcodeDecision(raw_ostream &o1, raw_ostream &o2,
 118                           unsigned &i1, unsigned &i2, unsigned &ModRMTableNum,
 119                           OpcodeDecision &decision) const;
 120
 121   /// emitContextDecision - Emits a ContextDecision and all its subsidiary
 122   ///   Opcode and ModRMDecisions.  A ContextDecision is printed as:
 123   ///
 124   ///   struct ContextDecision NAME = {
 125   ///     { /* OpcodeDecisions */
 126   ///       /* IC */
 127   ///       { /* struct OpcodeDecision */
 128   ///         ...
 129   ///       },
 130   ///       ...
 131   ///     }
 132   ///   }
 133   ///
 134   ///   NAME is the name of the ContextDecision (typically one of the four names
 135   ///   ONEBYTE_SYM, TWOBYTE_SYM, THREEBYTE38_SYM, THREEBYTE3A_SYM from
 136   ///   X86DisassemblerDecoderCommon.h).
 137   ///   IC is one of the contexts in InstructionContext.  There is an opcode
 138   ///   decision for each possible context.
 139   ///   The OpcodeDecision structures are printed as described in the
 140   ///   documentation for emitOpcodeDecision.
 141   ///
 142   /// @param o1       - The output stream to print the ID tables generated by
 143   ///                   emitModRMDecision() to.
 144   /// @param o2       - The output stream to print the decision structure to.
 145   /// @param i1       - The indent level to use with stream o1.
 146   /// @param i2       - The indent level to use with stream o2.
 147   /// @param ModRMTableNum - next table number for adding to ModRMTable.
 148   /// @param decision - The ContextDecision to emit along with its subsidiary
 149   ///                   structures.
 150   /// @param name     - The name for the ContextDecision.
 151   void emitContextDecision(raw_ostream &o1, raw_ostream &o2,
 152                            unsigned &i1, unsigned &i2, unsigned &ModRMTableNum,
 153                            ContextDecision &decision, const char* name) const;
 154
 155   /// emitInstructionInfo - Prints the instruction specifier table, which has
 156   ///   one entry for each instruction, and contains name and operand
 157   ///   information.  This table is printed as:
 158   ///
 159   ///   struct InstructionSpecifier CONTEXTS_SYM[k] = {
 160   ///     {
 161   ///       /* nnnn */
 162   ///       "MNEMONIC",
 163   ///       0xnn,
 164   ///       {
 165   ///         {
 166   ///           ENCODING,
 167   ///           TYPE
 168   ///         },
 169   ///         ...
 170   ///       }
 171   ///     },
 172   ///   };
 173   ///
 174   ///   k is the total number of instructions.
 175   ///   nnnn is the ID of the current instruction (0-based).  This table
 176   ///   includes entries for non-instructions like PHINODE.
 177   ///   0xnn is the lowest possible opcode for the current instruction, used for
 178   ///   AddRegFrm instructions to compute the operand's value.
 179   ///   ENCODING and TYPE describe the encoding and type for a single operand.
 180   ///
 181   /// @param o  - The output stream to which the instruction table should be
 182   ///             written.
 183   /// @param i  - The indent level for use with the stream.
 184   void emitInstructionInfo(raw_ostream &o, unsigned &i) const;
 185
 186   /// emitContextTable - Prints the table that is used to translate from an
 187   ///   instruction attribute mask to an instruction context.  This table is
 188   ///   printed as:
 189   ///
 190   ///   InstructionContext CONTEXTS_STR[256] = {
 191   ///     IC, /* 0x00 */
 192   ///     ...
 193   ///   };
 194   ///
 195   ///   IC is the context corresponding to the mask 0x00, and there are 256
 196   ///   possible masks.
 197   ///
 198   /// @param o  - The output stream to which the context table should be written.
 199   /// @param i  - The indent level for use with the stream.
 200   void emitContextTable(raw_ostream &o, uint32_t &i) const;
 201
 202   /// emitContextDecisions - Prints all four ContextDecision structures using
 203   ///   emitContextDecision().
 204   ///
 205   /// @param o1 - The output stream to print the ID tables generated by
 206   ///             emitModRMDecision() to.
 207   /// @param o2 - The output stream to print the decision structures to.
 208   /// @param i1 - The indent level to use with stream o1.
 209   /// @param i2 - The indent level to use with stream o2.
 210   /// @param ModRMTableNum - next table number for adding to ModRMTable.
 211   void emitContextDecisions(raw_ostream &o1, raw_ostream &o2,
 212                             unsigned &i1, unsigned &i2,
 213                             unsigned &ModRMTableNum) const;
 214
 215   /// setTableFields - Uses a ModRMFilter to set the appropriate entries in a
 216   ///   ModRMDecision to refer to a particular instruction ID.
 217   ///
 218   /// @param decision - The ModRMDecision to populate.
 219   /// @param filter   - The filter to use in deciding which entries to populate.
 220   /// @param uid      - The unique ID to set matching entries to.
 221   /// @param opcode   - The opcode of the instruction, for error reporting.
 222   void setTableFields(ModRMDecision &decision,
 223                       const ModRMFilter &filter,
 224                       InstrUID uid,
 225                       uint8_t opcode);
 226 public:
 227   /// Constructor - Allocates space for the class decisions and clears them.
 228   DisassemblerTables();
 229
 230   ~DisassemblerTables();
 231
 232   /// emit - Emits the instruction table, context table, and class decisions.
 233   ///
 234   /// @param o  - The output stream to print the tables to.
 235   void emit(raw_ostream &o) const;
 236
 237   /// setTableFields - Uses the opcode type, instruction context, opcode, and a
 238   ///   ModRMFilter as criteria to set a particular set of entries in the
 239   ///   decode tables to point to a specific uid.
 240   ///
 241   /// @param type         - The opcode type (ONEBYTE, TWOBYTE, etc.)
 242   /// @param insnContext  - The context to use (IC, IC_64BIT, etc.)
 243   /// @param opcode       - The last byte of the opcode (not counting any escape
 244   ///                       or extended opcodes).
 245   /// @param filter       - The ModRMFilter that decides which ModR/M byte values
 246   ///                       correspond to the desired instruction.
 247   /// @param uid          - The unique ID of the instruction.
 248   /// @param is32bit      - Instructon is only 32-bit
 249   /// @param noPrefix     - Instruction record has no prefix.
 250   /// @param ignoresVEX_L - Instruction ignores VEX.L
 251   /// @param ignoresVEX_W - Instruction ignores VEX.W
 252   /// @param AddrSize     - Instructions address size 16/32/64. 0 is unspecified
 253   void setTableFields(OpcodeType type,
 254                       InstructionContext insnContext,
 255                       uint8_t opcode,
 256                       const ModRMFilter &filter,
 257                       InstrUID uid,
 258                       bool is32bit,
 259                       bool noPrefix,
 260                       bool ignoresVEX_L,
 261                       bool ignoresVEX_W,
 262                       unsigned AddrSize);
 263
 264   /// specForUID - Returns the instruction specifier for a given unique
 265   ///   instruction ID.  Used when resolving collisions.
 266   ///
 267   /// @param uid  - The unique ID of the instruction.
 268   /// @return     - A reference to the instruction specifier.
 269   InstructionSpecifier& specForUID(InstrUID uid) {
 270     if (uid >= InstructionSpecifiers.size())
 271       InstructionSpecifiers.resize(uid + 1);
 272
 273     return InstructionSpecifiers[uid];
 274   }
 275
 276   // hasConflicts - Reports whether there were primary decode conflicts
 277   //   from any instructions added to the tables.
 278   // @return  - true if there were; false otherwise.
 279
 280   bool hasConflicts() {
 281     return HasConflicts;
 282   }
 283 };
 284
 285 } // namespace X86Disassembler
 286
 287 } // namespace llvm
 288
 289 #endif