utils/TableGen/X86DisassemblerTables.h

   1 //===- X86DisassemblerTables.h - Disassembler tables ------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is part of the X86 Disassembler Emitter.
  11 // It contains the interface of the disassembler tables.
  12 // Documentation for the disassembler emitter in general can be found in
  13 //  X86DisasemblerEmitter.h.
  14 //
  15 //===----------------------------------------------------------------------===//
  16
  17 #ifndef X86DISASSEMBLERTABLES_H
  18 #define X86DISASSEMBLERTABLES_H
  19
  20 #include "X86DisassemblerShared.h"
  21 #include "X86ModRMFilters.h"
  22
  23 #include "llvm/Support/raw_ostream.h"
  24
  25 #include <vector>
  26
  27 namespace llvm {
  28
  29 namespace X86Disassembler {
  30
  31 /// DisassemblerTables - Encapsulates all the decode tables being generated by
  32 ///   the table emitter.  Contains functions to populate the tables as well as
  33 ///   to emit them as hierarchical C structures suitable for consumption by the
  34 ///   runtime.
  35 class DisassemblerTables {
  36 private:
  37   /// The decoder tables.  There is one for each opcode type:
  38   /// [0] one-byte opcodes
  39   /// [1] two-byte opcodes of the form 0f __
  40   /// [2] three-byte opcodes of the form 0f 38 __
  41   /// [3] three-byte opcodes of the form 0f 3a __
  42   /// [4] three-byte opcodes of the form 0f a6 __
  43   /// [5] three-byte opcodes of the form 0f a7 __
  44   ContextDecision* Tables[6];
  45
  46   /// The instruction information table
  47   std::vector<InstructionSpecifier> InstructionSpecifiers;
  48
  49   /// True if there are primary decode conflicts in the instruction set
  50   bool HasConflicts;
  51
  52   /// emitOneID - Emits a table entry for a single instruction entry, at the
  53   ///   innermost level of the structure hierarchy.  The entry is printed out
  54   ///   in the format "nnnn, /* MNEMONIC */" where nnnn is the ID in decimal,
  55   ///   the comma is printed if addComma is true, and the menonic is the name
  56   ///   of the instruction as listed in the LLVM tables.
  57   ///
  58   /// @param o        - The output stream to print the entry on.
  59   /// @param i        - The indentation level for o.
  60   /// @param id       - The unique ID of the instruction to print.
  61   /// @param addComma - Whether or not to print a comma after the ID.  True if
  62   ///                    additional items will follow.
  63   void emitOneID(raw_ostream &o,
  64                  uint32_t &i,
  65                  InstrUID id,
  66                  bool addComma) const;
  67
  68   /// emitModRMDecision - Emits a table of entries corresponding to a single
  69   ///   ModR/M decision.  Compacts the ModR/M decision if possible.  ModR/M
  70   ///   decisions are printed as:
  71   ///
  72   ///   { /* struct ModRMDecision */
  73   ///     TYPE,
  74   ///     modRMTablennnn
  75   ///   }
  76   ///
  77   ///   where nnnn is a unique ID for the corresponding table of IDs.
  78   ///   TYPE indicates whether the table has one entry that is the same
  79   ///   regardless of ModR/M byte, two entries - one for bytes 0x00-0xbf and one
  80   ///   for bytes 0xc0-0xff -, or 256 entries, one for each possible byte.
  81   ///   nnnn is the number of a table for looking up these values.  The tables
  82   ///   are writen separately so that tables consisting entirely of zeros will
  83   ///   not be duplicated.  (These all have the name modRMEmptyTable.)  A table
  84   ///   is printed as:
  85   ///
  86   ///   InstrUID modRMTablennnn[k] = {
  87   ///     nnnn, /* MNEMONIC */
  88   ///     ...
  89   ///     nnnn /* MNEMONIC */
  90   ///   };
  91   ///
  92   /// @param o1       - The output stream to print the ID table to.
  93   /// @param o2       - The output stream to print the decision structure to.
  94   /// @param i1       - The indentation level to use with stream o1.
  95   /// @param i2       - The indentation level to use with stream o2.
  96   /// @param decision - The ModR/M decision to emit.  This decision has 256
  97   ///                   entries - emitModRMDecision decides how to compact it.
  98   void emitModRMDecision(raw_ostream &o1,
  99                          raw_ostream &o2,
 100                          uint32_t &i1,
 101                          uint32_t &i2,
 102                          ModRMDecision &decision) const;
 103
 104   /// emitOpcodeDecision - Emits an OpcodeDecision and all its subsidiary ModR/M
 105   ///   decisions.  An OpcodeDecision is printed as:
 106   ///
 107   ///   { /* struct OpcodeDecision */
 108   ///     /* 0x00 */
 109   ///     { /* struct ModRMDecision */
 110   ///       ...
 111   ///     }
 112   ///     ...
 113   ///   }
 114   ///
 115   ///   where the ModRMDecision structure is printed as described in the
 116   ///   documentation for emitModRMDecision().  emitOpcodeDecision() passes on a
 117   ///   stream and indent level for the UID tables generated by
 118   ///   emitModRMDecision(), but does not use them itself.
 119   ///
 120   /// @param o1       - The output stream to print the ID tables generated by
 121   ///                   emitModRMDecision() to.
 122   /// @param o2       - The output stream for the decision structure itself.
 123   /// @param i1       - The indent level to use with stream o1.
 124   /// @param i2       - The indent level to use with stream o2.
 125   /// @param decision - The OpcodeDecision to emit along with its subsidiary
 126   ///                    structures.
 127   void emitOpcodeDecision(raw_ostream &o1,
 128                           raw_ostream &o2,
 129                           uint32_t &i1,
 130                           uint32_t &i2,
 131                           OpcodeDecision &decision) const;
 132
 133   /// emitContextDecision - Emits a ContextDecision and all its subsidiary
 134   ///   Opcode and ModRMDecisions.  A ContextDecision is printed as:
 135   ///
 136   ///   struct ContextDecision NAME = {
 137   ///     { /* OpcodeDecisions */
 138   ///       /* IC */
 139   ///       { /* struct OpcodeDecision */
 140   ///         ...
 141   ///       },
 142   ///       ...
 143   ///     }
 144   ///   }
 145   ///
 146   ///   NAME is the name of the ContextDecision (typically one of the four names
 147   ///   ONEBYTE_SYM, TWOBYTE_SYM, THREEBYTE38_SYM, THREEBYTE3A_SYM,
 148   ///   THREEBYTEA6_SYM, and THREEBYTEA7_SYM from
 149   ///   X86DisassemblerDecoderCommon.h).
 150   ///   IC is one of the contexts in InstructionContext.  There is an opcode
 151   ///   decision for each possible context.
 152   ///   The OpcodeDecision structures are printed as described in the
 153   ///   documentation for emitOpcodeDecision.
 154   ///
 155   /// @param o1       - The output stream to print the ID tables generated by
 156   ///                   emitModRMDecision() to.
 157   /// @param o2       - The output stream to print the decision structure to.
 158   /// @param i1       - The indent level to use with stream o1.
 159   /// @param i2       - The indent level to use with stream o2.
 160   /// @param decision - The ContextDecision to emit along with its subsidiary
 161   ///                   structures.
 162   /// @param name     - The name for the ContextDecision.
 163   void emitContextDecision(raw_ostream &o1,
 164                            raw_ostream &o2,
 165                            uint32_t &i1,
 166                            uint32_t &i2,
 167                            ContextDecision &decision,
 168                            const char* name) const;
 169
 170   /// emitInstructionInfo - Prints the instruction specifier table, which has
 171   ///   one entry for each instruction, and contains name and operand
 172   ///   information.  This table is printed as:
 173   ///
 174   ///   struct InstructionSpecifier CONTEXTS_SYM[k] = {
 175   ///     {
 176   ///       /* nnnn */
 177   ///       "MNEMONIC",
 178   ///       0xnn,
 179   ///       {
 180   ///         {
 181   ///           ENCODING,
 182   ///           TYPE
 183   ///         },
 184   ///         ...
 185   ///       }
 186   ///     },
 187   ///   };
 188   ///
 189   ///   k is the total number of instructions.
 190   ///   nnnn is the ID of the current instruction (0-based).  This table
 191   ///   includes entries for non-instructions like PHINODE.
 192   ///   0xnn is the lowest possible opcode for the current instruction, used for
 193   ///   AddRegFrm instructions to compute the operand's value.
 194   ///   ENCODING and TYPE describe the encoding and type for a single operand.
 195   ///
 196   /// @param o  - The output stream to which the instruction table should be
 197   ///             written.
 198   /// @param i  - The indent level for use with the stream.
 199   void emitInstructionInfo(raw_ostream &o, uint32_t &i) const;
 200
 201   /// emitContextTable - Prints the table that is used to translate from an
 202   ///   instruction attribute mask to an instruction context.  This table is
 203   ///   printed as:
 204   ///
 205   ///   InstructionContext CONTEXTS_STR[256] = {
 206   ///     IC, /* 0x00 */
 207   ///     ...
 208   ///   };
 209   ///
 210   ///   IC is the context corresponding to the mask 0x00, and there are 256
 211   ///   possible masks.
 212   ///
 213   /// @param o  - The output stream to which the context table should be written.
 214   /// @param i  - The indent level for use with the stream.
 215   void emitContextTable(raw_ostream &o, uint32_t &i) const;
 216
 217   /// emitContextDecisions - Prints all four ContextDecision structures using
 218   ///   emitContextDecision().
 219   ///
 220   /// @param o1 - The output stream to print the ID tables generated by
 221   ///             emitModRMDecision() to.
 222   /// @param o2 - The output stream to print the decision structures to.
 223   /// @param i1 - The indent level to use with stream o1.
 224   /// @param i2 - The indent level to use with stream o2.
 225   void emitContextDecisions(raw_ostream &o1,
 226                             raw_ostream &o2,
 227                             uint32_t &i1,
 228                             uint32_t &i2) const;
 229
 230   /// setTableFields - Uses a ModRMFilter to set the appropriate entries in a
 231   ///   ModRMDecision to refer to a particular instruction ID.
 232   ///
 233   /// @param decision - The ModRMDecision to populate.
 234   /// @param filter   - The filter to use in deciding which entries to populate.
 235   /// @param uid      - The unique ID to set matching entries to.
 236   /// @param opcode   - The opcode of the instruction, for error reporting.
 237   void setTableFields(ModRMDecision &decision,
 238                       const ModRMFilter &filter,
 239                       InstrUID uid,
 240                       uint8_t opcode);
 241 public:
 242   /// Constructor - Allocates space for the class decisions and clears them.
 243   DisassemblerTables();
 244
 245   ~DisassemblerTables();
 246
 247   /// emit - Emits the instruction table, context table, and class decisions.
 248   ///
 249   /// @param o  - The output stream to print the tables to.
 250   void emit(raw_ostream &o) const;
 251
 252   /// setTableFields - Uses the opcode type, instruction context, opcode, and a
 253   ///   ModRMFilter as criteria to set a particular set of entries in the
 254   ///   decode tables to point to a specific uid.
 255   ///
 256   /// @param type         - The opcode type (ONEBYTE, TWOBYTE, etc.)
 257   /// @param insnContext  - The context to use (IC, IC_64BIT, etc.)
 258   /// @param opcode       - The last byte of the opcode (not counting any escape
 259   ///                       or extended opcodes).
 260   /// @param filter       - The ModRMFilter that decides which ModR/M byte values
 261   ///                       correspond to the desired instruction.
 262   /// @param uid          - The unique ID of the instruction.
 263   void setTableFields(OpcodeType type,
 264                       InstructionContext insnContext,
 265                       uint8_t opcode,
 266                       const ModRMFilter &filter,
 267                       InstrUID uid);
 268
 269   /// specForUID - Returns the instruction specifier for a given unique
 270   ///   instruction ID.  Used when resolving collisions.
 271   ///
 272   /// @param uid  - The unique ID of the instruction.
 273   /// @return     - A reference to the instruction specifier.
 274   InstructionSpecifier& specForUID(InstrUID uid) {
 275     if (uid >= InstructionSpecifiers.size())
 276       InstructionSpecifiers.resize(uid + 1);
 277
 278     return InstructionSpecifiers[uid];
 279   }
 280
 281   // hasConflicts - Reports whether there were primary decode conflicts
 282   //   from any instructions added to the tables.
 283   // @return  - true if there were; false otherwise.
 284
 285   bool hasConflicts() {
 286     return HasConflicts;
 287   }
 288 };
 289
 290 } // namespace X86Disassembler
 291
 292 } // namespace llvm
 293
 294 #endif