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