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