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 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   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   /// @param AddrSize     - Instructions address size 16/32/64. 0 is unspecified
249   void setTableFields(OpcodeType type,
250                       InstructionContext insnContext,
251                       uint8_t opcode,
252                       const ModRMFilter &filter,
253                       InstrUID uid,
254                       bool is32bit,
255                       bool ignoresVEX_L,
256                       unsigned AddrSize);
257 
258   /// specForUID - Returns the instruction specifier for a given unique
259   ///   instruction ID.  Used when resolving collisions.
260   ///
261   /// @param uid  - The unique ID of the instruction.
262   /// @return     - A reference to the instruction specifier.
specForUID(InstrUID uid)263   InstructionSpecifier& specForUID(InstrUID uid) {
264     if (uid >= InstructionSpecifiers.size())
265       InstructionSpecifiers.resize(uid + 1);
266 
267     return InstructionSpecifiers[uid];
268   }
269 
270   // hasConflicts - Reports whether there were primary decode conflicts
271   //   from any instructions added to the tables.
272   // @return  - true if there were; false otherwise.
273 
hasConflicts()274   bool hasConflicts() {
275     return HasConflicts;
276   }
277 };
278 
279 } // namespace X86Disassembler
280 
281 } // namespace llvm
282 
283 #endif
284