1 //===-- llvm/Target/TargetInstrInfo.h - Instruction Info --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file describes the target machine instructions to the code generator.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_TARGET_TARGETINSTRINFO_H
15 #define LLVM_TARGET_TARGETINSTRINFO_H
17 #include "llvm/CodeGen/MachineBasicBlock.h"
18 #include "llvm/Support/DataTypes.h"
31 class MachineCodeForInstruction;
33 //---------------------------------------------------------------------------
34 // Data types used to define information about a single machine instruction
35 //---------------------------------------------------------------------------
37 typedef short MachineOpCode;
38 typedef unsigned InstrSchedClass;
40 //---------------------------------------------------------------------------
41 // struct TargetInstrDescriptor:
42 // Predefined information about each machine instruction.
43 // Designed to initialized statically.
46 const unsigned M_NOP_FLAG = 1 << 0;
47 const unsigned M_BRANCH_FLAG = 1 << 1;
48 const unsigned M_CALL_FLAG = 1 << 2;
49 const unsigned M_RET_FLAG = 1 << 3;
50 const unsigned M_BARRIER_FLAG = 1 << 4;
51 const unsigned M_DELAY_SLOT_FLAG = 1 << 5;
52 const unsigned M_CC_FLAG = 1 << 6;
53 const unsigned M_LOAD_FLAG = 1 << 10;
54 const unsigned M_STORE_FLAG = 1 << 12;
55 // 3-addr instructions which really work like 2-addr ones, eg. X86 add/sub
56 const unsigned M_2_ADDR_FLAG = 1 << 15;
58 // M_TERMINATOR_FLAG - Is this instruction part of the terminator for a basic
59 // block? Typically this is things like return and branch instructions.
60 // Various passes use this to insert code into the bottom of a basic block, but
61 // before control flow occurs.
62 const unsigned M_TERMINATOR_FLAG = 1 << 16;
64 struct TargetInstrDescriptor {
65 const char * Name; // Assembly language mnemonic for the opcode.
66 int numOperands; // Number of args; -1 if variable #args
67 int resultPos; // Position of the result; -1 if no result
68 unsigned maxImmedConst; // Largest +ve constant in IMMED field or 0.
69 bool immedIsSignExtended; // Is IMMED field sign-extended? If so,
70 // smallest -ve value is -(maxImmedConst+1).
71 unsigned numDelaySlots; // Number of delay slots after instruction
72 unsigned latency; // Latency in machine cycles
73 InstrSchedClass schedClass; // enum identifying instr sched class
74 unsigned Flags; // flags identifying machine instr class
75 unsigned TSFlags; // Target Specific Flag values
76 const unsigned *ImplicitUses; // Registers implicitly read by this instr
77 const unsigned *ImplicitDefs; // Registers implicitly defined by this instr
81 //---------------------------------------------------------------------------
83 /// TargetInstrInfo - Interface to description of machine instructions
85 class TargetInstrInfo {
86 const TargetInstrDescriptor* desc; // raw array to allow static init'n
87 unsigned NumOpcodes; // number of entries in the desc array
88 unsigned numRealOpCodes; // number of non-dummy op codes
90 TargetInstrInfo(const TargetInstrInfo &); // DO NOT IMPLEMENT
91 void operator=(const TargetInstrInfo &); // DO NOT IMPLEMENT
93 TargetInstrInfo(const TargetInstrDescriptor *desc, unsigned NumOpcodes);
94 virtual ~TargetInstrInfo();
96 // Invariant: All instruction sets use opcode #0 as the PHI instruction
99 unsigned getNumOpcodes() const { return NumOpcodes; }
101 /// get - Return the machine instruction descriptor that corresponds to the
102 /// specified instruction opcode.
104 const TargetInstrDescriptor& get(MachineOpCode Opcode) const {
105 assert((unsigned)Opcode < NumOpcodes);
109 const char *getName(MachineOpCode Opcode) const {
110 return get(Opcode).Name;
113 int getNumOperands(MachineOpCode Opcode) const {
114 return get(Opcode).numOperands;
118 InstrSchedClass getSchedClass(MachineOpCode Opcode) const {
119 return get(Opcode).schedClass;
122 const unsigned *getImplicitUses(MachineOpCode Opcode) const {
123 return get(Opcode).ImplicitUses;
126 const unsigned *getImplicitDefs(MachineOpCode Opcode) const {
127 return get(Opcode).ImplicitDefs;
132 // Query instruction class flags according to the machine-independent
133 // flags listed above.
135 bool isReturn(MachineOpCode Opcode) const {
136 return get(Opcode).Flags & M_RET_FLAG;
139 bool isTwoAddrInstr(MachineOpCode Opcode) const {
140 return get(Opcode).Flags & M_2_ADDR_FLAG;
142 bool isTerminatorInstr(unsigned Opcode) const {
143 return get(Opcode).Flags & M_TERMINATOR_FLAG;
146 /// Return true if the instruction is a register to register move
147 /// and leave the source and dest operands in the passed parameters.
148 virtual bool isMoveInstr(const MachineInstr& MI,
150 unsigned& destReg) const {
154 /// Insert a goto (unconditional branch) sequence to TMBB, at the
156 virtual void insertGoto(MachineBasicBlock& MBB,
157 MachineBasicBlock& TMBB) const {
158 assert(0 && "Target didn't implement insertGoto!");
161 /// Reverses the branch condition of the MachineInstr pointed by
162 /// MI. The instruction is replaced and the new MI is returned.
163 virtual MachineBasicBlock::iterator
164 reverseBranchCondition(MachineBasicBlock::iterator MI) const {
165 assert(0 && "Target didn't implement reverseBranchCondition!");
170 //-------------------------------------------------------------------------
171 // Code generation support for creating individual machine instructions
173 // WARNING: These methods are Sparc specific
175 // DO NOT USE ANY OF THESE METHODS THEY ARE DEPRECATED!
177 //-------------------------------------------------------------------------
179 unsigned getNumDelaySlots(MachineOpCode Opcode) const {
180 return get(Opcode).numDelaySlots;
182 bool isCCInstr(MachineOpCode Opcode) const {
183 return get(Opcode).Flags & M_CC_FLAG;
185 bool isNop(MachineOpCode Opcode) const {
186 return get(Opcode).Flags & M_NOP_FLAG;
188 bool isBranch(MachineOpCode Opcode) const {
189 return get(Opcode).Flags & M_BRANCH_FLAG;
191 /// isBarrier - Returns true if the specified instruction stops control flow
192 /// from executing the instruction immediately following it. Examples include
193 /// unconditional branches and return instructions.
194 bool isBarrier(MachineOpCode Opcode) const {
195 return get(Opcode).Flags & M_BARRIER_FLAG;
198 bool isCall(MachineOpCode Opcode) const {
199 return get(Opcode).Flags & M_CALL_FLAG;
201 bool isLoad(MachineOpCode Opcode) const {
202 return get(Opcode).Flags & M_LOAD_FLAG;
204 bool isStore(MachineOpCode Opcode) const {
205 return get(Opcode).Flags & M_STORE_FLAG;
208 /// hasDelaySlot - Returns true if the specified instruction has a delay slot
209 /// which must be filled by the code generator.
210 bool hasDelaySlot(unsigned Opcode) const {
211 return get(Opcode).Flags & M_DELAY_SLOT_FLAG;
214 virtual bool hasResultInterlock(MachineOpCode Opcode) const {
219 // Latencies for individual instructions and instruction pairs
221 virtual int minLatency(MachineOpCode Opcode) const {
222 return get(Opcode).latency;
225 virtual int maxLatency(MachineOpCode Opcode) const {
226 return get(Opcode).latency;
230 // Which operand holds an immediate constant? Returns -1 if none
232 virtual int getImmedConstantPos(MachineOpCode Opcode) const {
233 return -1; // immediate position is machine specific, so say -1 == "none"
236 // Check if the specified constant fits in the immediate field
237 // of this machine instruction
239 virtual bool constantFitsInImmedField(MachineOpCode Opcode,
240 int64_t intValue) const;
242 // Return the largest positive constant that can be held in the IMMED field
243 // of this machine instruction.
244 // isSignExtended is set to true if the value is sign-extended before use
245 // (this is true for all immediate fields in SPARC instructions).
246 // Return 0 if the instruction has no IMMED field.
248 virtual uint64_t maxImmedConstant(MachineOpCode Opcode,
249 bool &isSignExtended) const {
250 isSignExtended = get(Opcode).immedIsSignExtended;
251 return get(Opcode).maxImmedConst;
255 } // End llvm namespace