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Diffstat (limited to 'utils/TableGen/X86RecognizableInstr.h')
| -rw-r--r-- | utils/TableGen/X86RecognizableInstr.h | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/utils/TableGen/X86RecognizableInstr.h b/utils/TableGen/X86RecognizableInstr.h new file mode 100644 index 0000000..84374b0 --- /dev/null +++ b/utils/TableGen/X86RecognizableInstr.h @@ -0,0 +1,237 @@ +//===- X86RecognizableInstr.h - Disassembler instruction spec ----*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is part of the X86 Disassembler Emitter. +// It contains the interface of a single recognizable instruction. +// Documentation for the disassembler emitter in general can be found in +// X86DisasemblerEmitter.h. +// +//===----------------------------------------------------------------------===// + +#ifndef X86RECOGNIZABLEINSTR_H +#define X86RECOGNIZABLEINSTR_H + +#include "X86DisassemblerTables.h" + +#include "CodeGenTarget.h" +#include "Record.h" + +#include "llvm/System/DataTypes.h" +#include "llvm/ADT/SmallVector.h" + +namespace llvm { + +namespace X86Disassembler { + +/// RecognizableInstr - Encapsulates all information required to decode a single +/// instruction, as extracted from the LLVM instruction tables. Has methods +/// to interpret the information available in the LLVM tables, and to emit the +/// instruction into DisassemblerTables. +class RecognizableInstr { +private: + /// The opcode of the instruction, as used in an MCInst + InstrUID UID; + /// The record from the .td files corresponding to this instruction + const Record* Rec; + /// The prefix field from the record + uint8_t Prefix; + /// The opcode field from the record; this is the opcode used in the Intel + /// encoding and therefore distinct from the UID + uint8_t Opcode; + /// The form field from the record + uint8_t Form; + /// The segment override field from the record + uint8_t SegOvr; + /// The hasOpSizePrefix field from the record + bool HasOpSizePrefix; + /// The hasREX_WPrefix field from the record + bool HasREX_WPrefix; + /// The hasLockPrefix field from the record + bool HasLockPrefix; + /// The isCodeGenOnly filed from the record + bool IsCodeGenOnly; + + /// The instruction name as listed in the tables + std::string Name; + /// The AT&T AsmString for the instruction + std::string AsmString; + + /// Indicates whether the instruction is SSE + bool IsSSE; + /// Indicates whether the instruction has FR operands - MOVs with FR operands + /// are typically ignored + bool HasFROperands; + /// Indicates whether the instruction should be emitted into the decode + /// tables; regardless, it will be emitted into the instruction info table + bool ShouldBeEmitted; + + /// The operands of the instruction, as listed in the CodeGenInstruction. + /// They are not one-to-one with operands listed in the MCInst; for example, + /// memory operands expand to 5 operands in the MCInst + const std::vector<CodeGenInstruction::OperandInfo>* Operands; + /// The description of the instruction that is emitted into the instruction + /// info table + InstructionSpecifier* Spec; + + /// insnContext - Returns the primary context in which the instruction is + /// valid. + /// + /// @return - The context in which the instruction is valid. + InstructionContext insnContext() const; + + enum filter_ret { + FILTER_STRONG, // instruction has no place in the instruction tables + FILTER_WEAK, // instruction may conflict, and should be eliminated if + // it does + FILTER_NORMAL // instruction should have high priority and generate an + // error if it conflcits with any other FILTER_NORMAL + // instruction + }; + + /// filter - Determines whether the instruction should be decodable. Some + /// instructions are pure intrinsics and use unencodable operands; many + /// synthetic instructions are duplicates of other instructions; other + /// instructions only differ in the logical way in which they are used, and + /// have the same decoding. Because these would cause decode conflicts, + /// they must be filtered out. + /// + /// @return - The degree of filtering to be applied (see filter_ret). + filter_ret filter() const; + + /// typeFromString - Translates an operand type from the string provided in + /// the LLVM tables to an OperandType for use in the operand specifier. + /// + /// @param s - The string, as extracted by calling Rec->getName() + /// on a CodeGenInstruction::OperandInfo. + /// @param isSSE - Indicates whether the instruction is an SSE + /// instruction. For SSE instructions, immediates are + /// fixed-size rather than being affected by the + /// mandatory OpSize prefix. + /// @param hasREX_WPrefix - Indicates whether the instruction has a REX.W + /// prefix. If it does, 32-bit register operands stay + /// 32-bit regardless of the operand size. + /// @param hasOpSizePrefix- Indicates whether the instruction has an OpSize + /// prefix. If it does not, then 16-bit register + /// operands stay 16-bit. + /// @return - The operand's type. + static OperandType typeFromString(const std::string& s, + bool isSSE, + bool hasREX_WPrefix, + bool hasOpSizePrefix); + + /// immediateEncodingFromString - Translates an immediate encoding from the + /// string provided in the LLVM tables to an OperandEncoding for use in + /// the operand specifier. + /// + /// @param s - See typeFromString(). + /// @param hasOpSizePrefix - Indicates whether the instruction has an OpSize + /// prefix. If it does not, then 16-bit immediate + /// operands stay 16-bit. + /// @return - The operand's encoding. + static OperandEncoding immediateEncodingFromString(const std::string &s, + bool hasOpSizePrefix); + + /// rmRegisterEncodingFromString - Like immediateEncodingFromString, but + /// handles operands that are in the REG field of the ModR/M byte. + static OperandEncoding rmRegisterEncodingFromString(const std::string &s, + bool hasOpSizePrefix); + + /// rmRegisterEncodingFromString - Like immediateEncodingFromString, but + /// handles operands that are in the REG field of the ModR/M byte. + static OperandEncoding roRegisterEncodingFromString(const std::string &s, + bool hasOpSizePrefix); + static OperandEncoding memoryEncodingFromString(const std::string &s, + bool hasOpSizePrefix); + static OperandEncoding relocationEncodingFromString(const std::string &s, + bool hasOpSizePrefix); + static OperandEncoding opcodeModifierEncodingFromString(const std::string &s, + bool hasOpSizePrefix); + + /// handleOperand - Converts a single operand from the LLVM table format to + /// the emitted table format, handling any duplicate operands it encounters + /// and then one non-duplicate. + /// + /// @param optional - Determines whether to assert that the + /// operand exists. + /// @param operandIndex - The index into the generated operand table. + /// Incremented by this function one or more + /// times to reflect possible duplicate + /// operands). + /// @param physicalOperandIndex - The index of the current operand into the + /// set of non-duplicate ('physical') operands. + /// Incremented by this function once. + /// @param numPhysicalOperands - The number of non-duplicate operands in the + /// instructions. + /// @param operandMapping - The operand mapping, which has an entry for + /// each operand that indicates whether it is a + /// duplicate, and of what. + void handleOperand(bool optional, + unsigned &operandIndex, + unsigned &physicalOperandIndex, + unsigned &numPhysicalOperands, + unsigned *operandMapping, + OperandEncoding (*encodingFromString) + (const std::string&, + bool hasOpSizePrefix)); + + /// shouldBeEmitted - Returns the shouldBeEmitted field. Although filter() + /// filters out many instructions, at various points in decoding we + /// determine that the instruction should not actually be decodable. In + /// particular, MMX MOV instructions aren't emitted, but they're only + /// identified during operand parsing. + /// + /// @return - true if at this point we believe the instruction should be + /// emitted; false if not. This will return false if filter() returns false + /// once emitInstructionSpecifier() has been called. + bool shouldBeEmitted() const { + return ShouldBeEmitted; + } + + /// emitInstructionSpecifier - Loads the instruction specifier for the current + /// instruction into a DisassemblerTables. + /// + /// @arg tables - The DisassemblerTables to populate with the specifier for + /// the current instruction. + void emitInstructionSpecifier(DisassemblerTables &tables); + + /// emitDecodePath - Populates the proper fields in the decode tables + /// corresponding to the decode paths for this instruction. + /// + /// @arg tables - The DisassemblerTables to populate with the decode + /// decode information for the current instruction. + void emitDecodePath(DisassemblerTables &tables) const; + + /// Constructor - Initializes a RecognizableInstr with the appropriate fields + /// from a CodeGenInstruction. + /// + /// @arg tables - The DisassemblerTables that the specifier will be added to. + /// @arg insn - The CodeGenInstruction to extract information from. + /// @arg uid - The unique ID of the current instruction. + RecognizableInstr(DisassemblerTables &tables, + const CodeGenInstruction &insn, + InstrUID uid); +public: + /// processInstr - Accepts a CodeGenInstruction and loads decode information + /// for it into a DisassemblerTables if appropriate. + /// + /// @arg tables - The DiassemblerTables to be populated with decode + /// information. + /// @arg insn - The CodeGenInstruction to be used as a source for this + /// information. + /// @uid - The unique ID of the instruction. + static void processInstr(DisassemblerTables &tables, + const CodeGenInstruction &insn, + InstrUID uid); +}; + +} // namespace X86Disassembler + +} // namespace llvm + +#endif |