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      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 #include "llvm/Support/raw_ostream.h"
     23 #include <map>
     24 #include <vector>
     25 
     26 namespace llvm {
     27 
     28 namespace X86Disassembler {
     29 
     30 /// DisassemblerTables - Encapsulates all the decode tables being generated by
     31 ///   the table emitter.  Contains functions to populate the tables as well as
     32 ///   to emit them as hierarchical C structures suitable for consumption by the
     33 ///   runtime.
     34 class DisassemblerTables {
     35 private:
     36   /// The decoder tables.  There is one for each opcode type:
     37   /// [0] one-byte opcodes
     38   /// [1] two-byte opcodes of the form 0f __
     39   /// [2] three-byte opcodes of the form 0f 38 __
     40   /// [3] three-byte opcodes of the form 0f 3a __
     41   /// [4] XOP8 map opcode
     42   /// [5] XOP9 map opcode
     43   /// [6] XOPA map opcode
     44   ContextDecision* Tables[7];
     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 ignoresVEX_L - Instruction ignores VEX.L
    248   void setTableFields(OpcodeType type,
    249                       InstructionContext insnContext,
    250                       uint8_t opcode,
    251                       const ModRMFilter &filter,
    252                       InstrUID uid,
    253                       bool is32bit,
    254                       bool ignoresVEX_L);
    255 
    256   /// specForUID - Returns the instruction specifier for a given unique
    257   ///   instruction ID.  Used when resolving collisions.
    258   ///
    259   /// @param uid  - The unique ID of the instruction.
    260   /// @return     - A reference to the instruction specifier.
    261   InstructionSpecifier& specForUID(InstrUID uid) {
    262     if (uid >= InstructionSpecifiers.size())
    263       InstructionSpecifiers.resize(uid + 1);
    264 
    265     return InstructionSpecifiers[uid];
    266   }
    267 
    268   // hasConflicts - Reports whether there were primary decode conflicts
    269   //   from any instructions added to the tables.
    270   // @return  - true if there were; false otherwise.
    271 
    272   bool hasConflicts() {
    273     return HasConflicts;
    274   }
    275 };
    276 
    277 } // namespace X86Disassembler
    278 
    279 } // namespace llvm
    280 
    281 #endif
    282