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      1 /*===- X86DisassemblerDecoderCommon.h - Disassembler decoder -------*- 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.
     11  * It contains common definitions used by both the disassembler and the table
     12  *  generator.
     13  * Documentation for the disassembler can be found in X86Disassembler.h.
     14  *
     15  *===----------------------------------------------------------------------===*/
     16 
     17 /*
     18  * This header file provides those definitions that need to be shared between
     19  * the decoder and the table generator in a C-friendly manner.
     20  */
     21 
     22 #ifndef X86DISASSEMBLERDECODERCOMMON_H
     23 #define X86DISASSEMBLERDECODERCOMMON_H
     24 
     25 #include "llvm/Support/DataTypes.h"
     26 
     27 #define INSTRUCTIONS_SYM  x86DisassemblerInstrSpecifiers
     28 #define CONTEXTS_SYM      x86DisassemblerContexts
     29 #define ONEBYTE_SYM       x86DisassemblerOneByteOpcodes
     30 #define TWOBYTE_SYM       x86DisassemblerTwoByteOpcodes
     31 #define THREEBYTE38_SYM   x86DisassemblerThreeByte38Opcodes
     32 #define THREEBYTE3A_SYM   x86DisassemblerThreeByte3AOpcodes
     33 #define THREEBYTEA6_SYM   x86DisassemblerThreeByteA6Opcodes
     34 #define THREEBYTEA7_SYM   x86DisassemblerThreeByteA7Opcodes
     35 
     36 #define INSTRUCTIONS_STR  "x86DisassemblerInstrSpecifiers"
     37 #define CONTEXTS_STR      "x86DisassemblerContexts"
     38 #define ONEBYTE_STR       "x86DisassemblerOneByteOpcodes"
     39 #define TWOBYTE_STR       "x86DisassemblerTwoByteOpcodes"
     40 #define THREEBYTE38_STR   "x86DisassemblerThreeByte38Opcodes"
     41 #define THREEBYTE3A_STR   "x86DisassemblerThreeByte3AOpcodes"
     42 #define THREEBYTEA6_STR   "x86DisassemblerThreeByteA6Opcodes"
     43 #define THREEBYTEA7_STR   "x86DisassemblerThreeByteA7Opcodes"
     44 
     45 /*
     46  * Attributes of an instruction that must be known before the opcode can be
     47  * processed correctly.  Most of these indicate the presence of particular
     48  * prefixes, but ATTR_64BIT is simply an attribute of the decoding context.
     49  */
     50 #define ATTRIBUTE_BITS          \
     51   ENUM_ENTRY(ATTR_NONE,   0x00) \
     52   ENUM_ENTRY(ATTR_64BIT,  0x01) \
     53   ENUM_ENTRY(ATTR_XS,     0x02) \
     54   ENUM_ENTRY(ATTR_XD,     0x04) \
     55   ENUM_ENTRY(ATTR_REXW,   0x08) \
     56   ENUM_ENTRY(ATTR_OPSIZE, 0x10) \
     57   ENUM_ENTRY(ATTR_VEX,    0x20) \
     58   ENUM_ENTRY(ATTR_VEXL,   0x40)
     59 
     60 #define ENUM_ENTRY(n, v) n = v,
     61 enum attributeBits {
     62   ATTRIBUTE_BITS
     63   ATTR_max
     64 };
     65 #undef ENUM_ENTRY
     66 
     67 /*
     68  * Combinations of the above attributes that are relevant to instruction
     69  * decode.  Although other combinations are possible, they can be reduced to
     70  * these without affecting the ultimately decoded instruction.
     71  */
     72 
     73 /*           Class name           Rank  Rationale for rank assignment         */
     74 #define INSTRUCTION_CONTEXTS                                                   \
     75   ENUM_ENTRY(IC,                    0,  "says nothing about the instruction")  \
     76   ENUM_ENTRY(IC_64BIT,              1,  "says the instruction applies in "     \
     77                                         "64-bit mode but no more")             \
     78   ENUM_ENTRY(IC_OPSIZE,             3,  "requires an OPSIZE prefix, so "       \
     79                                         "operands change width")               \
     80   ENUM_ENTRY(IC_XD,                 2,  "may say something about the opcode "  \
     81                                         "but not the operands")                \
     82   ENUM_ENTRY(IC_XS,                 2,  "may say something about the opcode "  \
     83                                         "but not the operands")                \
     84   ENUM_ENTRY(IC_XD_OPSIZE,          3,  "requires an OPSIZE prefix, so "       \
     85                                         "operands change width")               \
     86   ENUM_ENTRY(IC_XS_OPSIZE,          3,  "requires an OPSIZE prefix, so "       \
     87                                         "operands change width")               \
     88   ENUM_ENTRY(IC_64BIT_REXW,         4,  "requires a REX.W prefix, so operands "\
     89                                         "change width; overrides IC_OPSIZE")   \
     90   ENUM_ENTRY(IC_64BIT_OPSIZE,       3,  "Just as meaningful as IC_OPSIZE")     \
     91   ENUM_ENTRY(IC_64BIT_XD,           5,  "XD instructions are SSE; REX.W is "   \
     92                                         "secondary")                           \
     93   ENUM_ENTRY(IC_64BIT_XS,           5,  "Just as meaningful as IC_64BIT_XD")   \
     94   ENUM_ENTRY(IC_64BIT_XD_OPSIZE,    3,  "Just as meaningful as IC_XD_OPSIZE")  \
     95   ENUM_ENTRY(IC_64BIT_XS_OPSIZE,    3,  "Just as meaningful as IC_XS_OPSIZE")  \
     96   ENUM_ENTRY(IC_64BIT_REXW_XS,      6,  "OPSIZE could mean a different "       \
     97                                         "opcode")                              \
     98   ENUM_ENTRY(IC_64BIT_REXW_XD,      6,  "Just as meaningful as "               \
     99                                         "IC_64BIT_REXW_XS")                    \
    100   ENUM_ENTRY(IC_64BIT_REXW_OPSIZE,  7,  "The Dynamic Duo!  Prefer over all "   \
    101                                         "else because this changes most "      \
    102                                         "operands' meaning")                   \
    103   ENUM_ENTRY(IC_VEX,                1,  "requires a VEX prefix")               \
    104   ENUM_ENTRY(IC_VEX_XS,             2,  "requires VEX and the XS prefix")      \
    105   ENUM_ENTRY(IC_VEX_XD,             2,  "requires VEX and the XD prefix")      \
    106   ENUM_ENTRY(IC_VEX_OPSIZE,         2,  "requires VEX and the OpSize prefix")  \
    107   ENUM_ENTRY(IC_VEX_W,              3,  "requires VEX and the W prefix")       \
    108   ENUM_ENTRY(IC_VEX_W_XS,           4,  "requires VEX, W, and XS prefix")      \
    109   ENUM_ENTRY(IC_VEX_W_XD,           4,  "requires VEX, W, and XD prefix")      \
    110   ENUM_ENTRY(IC_VEX_W_OPSIZE,       4,  "requires VEX, W, and OpSize")         \
    111   ENUM_ENTRY(IC_VEX_L,              3,  "requires VEX and the L prefix")       \
    112   ENUM_ENTRY(IC_VEX_L_XS,           4,  "requires VEX and the L and XS prefix")\
    113   ENUM_ENTRY(IC_VEX_L_XD,           4,  "requires VEX and the L and XD prefix")\
    114   ENUM_ENTRY(IC_VEX_L_OPSIZE,       4,  "requires VEX, L, and OpSize")
    115 
    116 
    117 #define ENUM_ENTRY(n, r, d) n,
    118 typedef enum {
    119   INSTRUCTION_CONTEXTS
    120   IC_max
    121 } InstructionContext;
    122 #undef ENUM_ENTRY
    123 
    124 /*
    125  * Opcode types, which determine which decode table to use, both in the Intel
    126  * manual and also for the decoder.
    127  */
    128 typedef enum {
    129   ONEBYTE       = 0,
    130   TWOBYTE       = 1,
    131   THREEBYTE_38  = 2,
    132   THREEBYTE_3A  = 3,
    133   THREEBYTE_A6  = 4,
    134   THREEBYTE_A7  = 5
    135 } OpcodeType;
    136 
    137 /*
    138  * The following structs are used for the hierarchical decode table.  After
    139  * determining the instruction's class (i.e., which IC_* constant applies to
    140  * it), the decoder reads the opcode.  Some instructions require specific
    141  * values of the ModR/M byte, so the ModR/M byte indexes into the final table.
    142  *
    143  * If a ModR/M byte is not required, "required" is left unset, and the values
    144  * for each instructionID are identical.
    145  */
    146 
    147 typedef uint16_t InstrUID;
    148 
    149 /*
    150  * ModRMDecisionType - describes the type of ModR/M decision, allowing the
    151  * consumer to determine the number of entries in it.
    152  *
    153  * MODRM_ONEENTRY - No matter what the value of the ModR/M byte is, the decoded
    154  *                  instruction is the same.
    155  * MODRM_SPLITRM  - If the ModR/M byte is between 0x00 and 0xbf, the opcode
    156  *                  corresponds to one instruction; otherwise, it corresponds to
    157  *                  a different instruction.
    158  * MODRM_FULL     - Potentially, each value of the ModR/M byte could correspond
    159  *                  to a different instruction.
    160  */
    161 
    162 #define MODRMTYPES            \
    163   ENUM_ENTRY(MODRM_ONEENTRY)  \
    164   ENUM_ENTRY(MODRM_SPLITRM)   \
    165   ENUM_ENTRY(MODRM_FULL)
    166 
    167 #define ENUM_ENTRY(n) n,
    168 typedef enum {
    169   MODRMTYPES
    170   MODRM_max
    171 } ModRMDecisionType;
    172 #undef ENUM_ENTRY
    173 
    174 /*
    175  * ModRMDecision - Specifies whether a ModR/M byte is needed and (if so) which
    176  *  instruction each possible value of the ModR/M byte corresponds to.  Once
    177  *  this information is known, we have narrowed down to a single instruction.
    178  */
    179 struct ModRMDecision {
    180   uint8_t     modrm_type;
    181 
    182   /* The macro below must be defined wherever this file is included. */
    183   INSTRUCTION_IDS
    184 };
    185 
    186 /*
    187  * OpcodeDecision - Specifies which set of ModR/M->instruction tables to look at
    188  *   given a particular opcode.
    189  */
    190 struct OpcodeDecision {
    191   struct ModRMDecision modRMDecisions[256];
    192 };
    193 
    194 /*
    195  * ContextDecision - Specifies which opcode->instruction tables to look at given
    196  *   a particular context (set of attributes).  Since there are many possible
    197  *   contexts, the decoder first uses CONTEXTS_SYM to determine which context
    198  *   applies given a specific set of attributes.  Hence there are only IC_max
    199  *   entries in this table, rather than 2^(ATTR_max).
    200  */
    201 struct ContextDecision {
    202   struct OpcodeDecision opcodeDecisions[IC_max];
    203 };
    204 
    205 /*
    206  * Physical encodings of instruction operands.
    207  */
    208 
    209 #define ENCODINGS                                                              \
    210   ENUM_ENTRY(ENCODING_NONE,   "")                                              \
    211   ENUM_ENTRY(ENCODING_REG,    "Register operand in ModR/M byte.")              \
    212   ENUM_ENTRY(ENCODING_RM,     "R/M operand in ModR/M byte.")                   \
    213   ENUM_ENTRY(ENCODING_VVVV,   "Register operand in VEX.vvvv byte.")            \
    214   ENUM_ENTRY(ENCODING_CB,     "1-byte code offset (possible new CS value)")    \
    215   ENUM_ENTRY(ENCODING_CW,     "2-byte")                                        \
    216   ENUM_ENTRY(ENCODING_CD,     "4-byte")                                        \
    217   ENUM_ENTRY(ENCODING_CP,     "6-byte")                                        \
    218   ENUM_ENTRY(ENCODING_CO,     "8-byte")                                        \
    219   ENUM_ENTRY(ENCODING_CT,     "10-byte")                                       \
    220   ENUM_ENTRY(ENCODING_IB,     "1-byte immediate")                              \
    221   ENUM_ENTRY(ENCODING_IW,     "2-byte")                                        \
    222   ENUM_ENTRY(ENCODING_ID,     "4-byte")                                        \
    223   ENUM_ENTRY(ENCODING_IO,     "8-byte")                                        \
    224   ENUM_ENTRY(ENCODING_RB,     "(AL..DIL, R8L..R15L) Register code added to "   \
    225                               "the opcode byte")                               \
    226   ENUM_ENTRY(ENCODING_RW,     "(AX..DI, R8W..R15W)")                           \
    227   ENUM_ENTRY(ENCODING_RD,     "(EAX..EDI, R8D..R15D)")                         \
    228   ENUM_ENTRY(ENCODING_RO,     "(RAX..RDI, R8..R15)")                           \
    229   ENUM_ENTRY(ENCODING_I,      "Position on floating-point stack added to the " \
    230                               "opcode byte")                                   \
    231                                                                                \
    232   ENUM_ENTRY(ENCODING_Iv,     "Immediate of operand size")                     \
    233   ENUM_ENTRY(ENCODING_Ia,     "Immediate of address size")                     \
    234   ENUM_ENTRY(ENCODING_Rv,     "Register code of operand size added to the "    \
    235                               "opcode byte")                                   \
    236   ENUM_ENTRY(ENCODING_DUP,    "Duplicate of another operand; ID is encoded "   \
    237                               "in type")
    238 
    239 #define ENUM_ENTRY(n, d) n,
    240   typedef enum {
    241     ENCODINGS
    242     ENCODING_max
    243   } OperandEncoding;
    244 #undef ENUM_ENTRY
    245 
    246 /*
    247  * Semantic interpretations of instruction operands.
    248  */
    249 
    250 #define TYPES                                                                  \
    251   ENUM_ENTRY(TYPE_NONE,       "")                                              \
    252   ENUM_ENTRY(TYPE_REL8,       "1-byte immediate address")                      \
    253   ENUM_ENTRY(TYPE_REL16,      "2-byte")                                        \
    254   ENUM_ENTRY(TYPE_REL32,      "4-byte")                                        \
    255   ENUM_ENTRY(TYPE_REL64,      "8-byte")                                        \
    256   ENUM_ENTRY(TYPE_PTR1616,    "2+2-byte segment+offset address")               \
    257   ENUM_ENTRY(TYPE_PTR1632,    "2+4-byte")                                      \
    258   ENUM_ENTRY(TYPE_PTR1664,    "2+8-byte")                                      \
    259   ENUM_ENTRY(TYPE_R8,         "1-byte register operand")                       \
    260   ENUM_ENTRY(TYPE_R16,        "2-byte")                                        \
    261   ENUM_ENTRY(TYPE_R32,        "4-byte")                                        \
    262   ENUM_ENTRY(TYPE_R64,        "8-byte")                                        \
    263   ENUM_ENTRY(TYPE_IMM8,       "1-byte immediate operand")                      \
    264   ENUM_ENTRY(TYPE_IMM16,      "2-byte")                                        \
    265   ENUM_ENTRY(TYPE_IMM32,      "4-byte")                                        \
    266   ENUM_ENTRY(TYPE_IMM64,      "8-byte")                                        \
    267   ENUM_ENTRY(TYPE_IMM3,       "1-byte immediate operand between 0 and 7")      \
    268   ENUM_ENTRY(TYPE_RM8,        "1-byte register or memory operand")             \
    269   ENUM_ENTRY(TYPE_RM16,       "2-byte")                                        \
    270   ENUM_ENTRY(TYPE_RM32,       "4-byte")                                        \
    271   ENUM_ENTRY(TYPE_RM64,       "8-byte")                                        \
    272   ENUM_ENTRY(TYPE_M,          "Memory operand")                                \
    273   ENUM_ENTRY(TYPE_M8,         "1-byte")                                        \
    274   ENUM_ENTRY(TYPE_M16,        "2-byte")                                        \
    275   ENUM_ENTRY(TYPE_M32,        "4-byte")                                        \
    276   ENUM_ENTRY(TYPE_M64,        "8-byte")                                        \
    277   ENUM_ENTRY(TYPE_LEA,        "Effective address")                             \
    278   ENUM_ENTRY(TYPE_M128,       "16-byte (SSE/SSE2)")                            \
    279   ENUM_ENTRY(TYPE_M256,       "256-byte (AVX)")                                \
    280   ENUM_ENTRY(TYPE_M1616,      "2+2-byte segment+offset address")               \
    281   ENUM_ENTRY(TYPE_M1632,      "2+4-byte")                                      \
    282   ENUM_ENTRY(TYPE_M1664,      "2+8-byte")                                      \
    283   ENUM_ENTRY(TYPE_M16_32,     "2+4-byte two-part memory operand (LIDT, LGDT)") \
    284   ENUM_ENTRY(TYPE_M16_16,     "2+2-byte (BOUND)")                              \
    285   ENUM_ENTRY(TYPE_M32_32,     "4+4-byte (BOUND)")                              \
    286   ENUM_ENTRY(TYPE_M16_64,     "2+8-byte (LIDT, LGDT)")                         \
    287   ENUM_ENTRY(TYPE_MOFFS8,     "1-byte memory offset (relative to segment "     \
    288                               "base)")                                         \
    289   ENUM_ENTRY(TYPE_MOFFS16,    "2-byte")                                        \
    290   ENUM_ENTRY(TYPE_MOFFS32,    "4-byte")                                        \
    291   ENUM_ENTRY(TYPE_MOFFS64,    "8-byte")                                        \
    292   ENUM_ENTRY(TYPE_SREG,       "Byte with single bit set: 0 = ES, 1 = CS, "     \
    293                               "2 = SS, 3 = DS, 4 = FS, 5 = GS")                \
    294   ENUM_ENTRY(TYPE_M32FP,      "32-bit IEE754 memory floating-point operand")   \
    295   ENUM_ENTRY(TYPE_M64FP,      "64-bit")                                        \
    296   ENUM_ENTRY(TYPE_M80FP,      "80-bit extended")                               \
    297   ENUM_ENTRY(TYPE_M16INT,     "2-byte memory integer operand for use in "      \
    298                               "floating-point instructions")                   \
    299   ENUM_ENTRY(TYPE_M32INT,     "4-byte")                                        \
    300   ENUM_ENTRY(TYPE_M64INT,     "8-byte")                                        \
    301   ENUM_ENTRY(TYPE_ST,         "Position on the floating-point stack")          \
    302   ENUM_ENTRY(TYPE_MM,         "MMX register operand")                          \
    303   ENUM_ENTRY(TYPE_MM32,       "4-byte MMX register or memory operand")         \
    304   ENUM_ENTRY(TYPE_MM64,       "8-byte")                                        \
    305   ENUM_ENTRY(TYPE_XMM,        "XMM register operand")                          \
    306   ENUM_ENTRY(TYPE_XMM32,      "4-byte XMM register or memory operand")         \
    307   ENUM_ENTRY(TYPE_XMM64,      "8-byte")                                        \
    308   ENUM_ENTRY(TYPE_XMM128,     "16-byte")                                       \
    309   ENUM_ENTRY(TYPE_XMM256,     "32-byte")                                       \
    310   ENUM_ENTRY(TYPE_XMM0,       "Implicit use of XMM0")                          \
    311   ENUM_ENTRY(TYPE_SEGMENTREG, "Segment register operand")                      \
    312   ENUM_ENTRY(TYPE_DEBUGREG,   "Debug register operand")                        \
    313   ENUM_ENTRY(TYPE_CONTROLREG, "Control register operand")                      \
    314                                                                                \
    315   ENUM_ENTRY(TYPE_Mv,         "Memory operand of operand size")                \
    316   ENUM_ENTRY(TYPE_Rv,         "Register operand of operand size")              \
    317   ENUM_ENTRY(TYPE_IMMv,       "Immediate operand of operand size")             \
    318   ENUM_ENTRY(TYPE_RELv,       "Immediate address of operand size")             \
    319   ENUM_ENTRY(TYPE_DUP0,       "Duplicate of operand 0")                        \
    320   ENUM_ENTRY(TYPE_DUP1,       "operand 1")                                     \
    321   ENUM_ENTRY(TYPE_DUP2,       "operand 2")                                     \
    322   ENUM_ENTRY(TYPE_DUP3,       "operand 3")                                     \
    323   ENUM_ENTRY(TYPE_DUP4,       "operand 4")                                     \
    324   ENUM_ENTRY(TYPE_M512,       "512-bit FPU/MMX/XMM/MXCSR state")
    325 
    326 #define ENUM_ENTRY(n, d) n,
    327 typedef enum {
    328   TYPES
    329   TYPE_max
    330 } OperandType;
    331 #undef ENUM_ENTRY
    332 
    333 /*
    334  * OperandSpecifier - The specification for how to extract and interpret one
    335  *   operand.
    336  */
    337 struct OperandSpecifier {
    338   OperandEncoding  encoding;
    339   OperandType      type;
    340 };
    341 
    342 /*
    343  * Indicates where the opcode modifier (if any) is to be found.  Extended
    344  * opcodes with AddRegFrm have the opcode modifier in the ModR/M byte.
    345  */
    346 
    347 #define MODIFIER_TYPES        \
    348   ENUM_ENTRY(MODIFIER_NONE)   \
    349   ENUM_ENTRY(MODIFIER_OPCODE) \
    350   ENUM_ENTRY(MODIFIER_MODRM)
    351 
    352 #define ENUM_ENTRY(n) n,
    353 typedef enum {
    354   MODIFIER_TYPES
    355   MODIFIER_max
    356 } ModifierType;
    357 #undef ENUM_ENTRY
    358 
    359 #define X86_MAX_OPERANDS 5
    360 
    361 /*
    362  * The specification for how to extract and interpret a full instruction and
    363  * its operands.
    364  */
    365 struct InstructionSpecifier {
    366   ModifierType modifierType;
    367   uint8_t modifierBase;
    368   struct OperandSpecifier operands[X86_MAX_OPERANDS];
    369 
    370   /* The macro below must be defined wherever this file is included. */
    371   INSTRUCTION_SPECIFIER_FIELDS
    372 };
    373 
    374 /*
    375  * Decoding mode for the Intel disassembler.  16-bit, 32-bit, and 64-bit mode
    376  * are supported, and represent real mode, IA-32e, and IA-32e in 64-bit mode,
    377  * respectively.
    378  */
    379 typedef enum {
    380   MODE_16BIT,
    381   MODE_32BIT,
    382   MODE_64BIT
    383 } DisassemblerMode;
    384 
    385 #endif
    386