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_CC_FLAG = 1 << 6;
52 const unsigned M_LOAD_FLAG = 1 << 10;
53 const unsigned M_STORE_FLAG = 1 << 12;
54 // 3-addr instructions which really work like 2-addr ones, eg. X86 add/sub
55 const unsigned M_2_ADDR_FLAG = 1 << 15;
57 // M_TERMINATOR_FLAG - Is this instruction part of the terminator for a basic
58 // block? Typically this is things like return and branch instructions.
59 // Various passes use this to insert code into the bottom of a basic block, but
60 // before control flow occurs.
61 const unsigned M_TERMINATOR_FLAG = 1 << 16;
63 struct TargetInstrDescriptor {
64 const char * Name; // Assembly language mnemonic for the opcode.
65 int numOperands; // Number of args; -1 if variable #args
66 int resultPos; // Position of the result; -1 if no result
67 unsigned maxImmedConst; // Largest +ve constant in IMMED field or 0.
68 bool immedIsSignExtended; // Is IMMED field sign-extended? If so,
69 // smallest -ve value is -(maxImmedConst+1).
70 unsigned numDelaySlots; // Number of delay slots after instruction
71 unsigned latency; // Latency in machine cycles
72 InstrSchedClass schedClass; // enum identifying instr sched class
73 unsigned Flags; // flags identifying machine instr class
74 unsigned TSFlags; // Target Specific Flag values
75 const unsigned *ImplicitUses; // Registers implicitly read by this instr
76 const unsigned *ImplicitDefs; // Registers implicitly defined by this instr
80 //---------------------------------------------------------------------------
82 /// TargetInstrInfo - Interface to description of machine instructions
84 class TargetInstrInfo {
85 const TargetInstrDescriptor* desc; // raw array to allow static init'n
86 unsigned NumOpcodes; // number of entries in the desc array
87 unsigned numRealOpCodes; // number of non-dummy op codes
89 TargetInstrInfo(const TargetInstrInfo &); // DO NOT IMPLEMENT
90 void operator=(const TargetInstrInfo &); // DO NOT IMPLEMENT
92 TargetInstrInfo(const TargetInstrDescriptor *desc, unsigned NumOpcodes);
93 virtual ~TargetInstrInfo();
95 // Invariant: All instruction sets use opcode #0 as the PHI instruction
98 unsigned getNumOpcodes() const { return NumOpcodes; }
100 /// get - Return the machine instruction descriptor that corresponds to the
101 /// specified instruction opcode.
103 const TargetInstrDescriptor& get(MachineOpCode Opcode) const {
104 assert((unsigned)Opcode < NumOpcodes);
108 const char *getName(MachineOpCode Opcode) const {
109 return get(Opcode).Name;
112 int getNumOperands(MachineOpCode Opcode) const {
113 return get(Opcode).numOperands;
117 InstrSchedClass getSchedClass(MachineOpCode Opcode) const {
118 return get(Opcode).schedClass;
121 const unsigned *getImplicitUses(MachineOpCode Opcode) const {
122 return get(Opcode).ImplicitUses;
125 const unsigned *getImplicitDefs(MachineOpCode Opcode) const {
126 return get(Opcode).ImplicitDefs;
131 // Query instruction class flags according to the machine-independent
132 // flags listed above.
134 bool isReturn(MachineOpCode Opcode) const {
135 return get(Opcode).Flags & M_RET_FLAG;
138 bool isTwoAddrInstr(MachineOpCode Opcode) const {
139 return get(Opcode).Flags & M_2_ADDR_FLAG;
141 bool isTerminatorInstr(unsigned Opcode) const {
142 return get(Opcode).Flags & M_TERMINATOR_FLAG;
145 /// Return true if the instruction is a register to register move
146 /// and leave the source and dest operands in the passed parameters.
147 virtual bool isMoveInstr(const MachineInstr& MI,
149 unsigned& destReg) const {
153 /// Insert a goto (unconditional branch) sequence to TMBB, at the
155 virtual void insertGoto(MachineBasicBlock& MBB,
156 MachineBasicBlock& TMBB) const {
157 assert(0 && "Target didn't implement insertGoto!");
160 /// Reverses the branch condition of the MachineInstr pointed by
161 /// MI. The instruction is replaced and the new MI is returned.
162 virtual MachineBasicBlock::iterator
163 reverseBranchCondition(MachineBasicBlock::iterator MI) const {
164 assert(0 && "Target didn't implement reverseBranchCondition!");
169 //-------------------------------------------------------------------------
170 // Code generation support for creating individual machine instructions
172 // WARNING: These methods are Sparc specific
174 // DO NOT USE ANY OF THESE METHODS THEY ARE DEPRECATED!
176 //-------------------------------------------------------------------------
178 unsigned getNumDelaySlots(MachineOpCode Opcode) const {
179 return get(Opcode).numDelaySlots;
181 bool isCCInstr(MachineOpCode Opcode) const {
182 return get(Opcode).Flags & M_CC_FLAG;
184 bool isNop(MachineOpCode Opcode) const {
185 return get(Opcode).Flags & M_NOP_FLAG;
187 bool isBranch(MachineOpCode Opcode) const {
188 return get(Opcode).Flags & M_BRANCH_FLAG;
190 /// isBarrier - Returns true if the specified instruction stops control flow
191 /// from executing the instruction immediately following it. Examples include
192 /// unconditional branches and return instructions.
193 bool isBarrier(MachineOpCode Opcode) const {
194 return get(Opcode).Flags & M_BARRIER_FLAG;
196 bool isCall(MachineOpCode Opcode) const {
197 return get(Opcode).Flags & M_CALL_FLAG;
199 bool isLoad(MachineOpCode Opcode) const {
200 return get(Opcode).Flags & M_LOAD_FLAG;
202 bool isStore(MachineOpCode Opcode) const {
203 return get(Opcode).Flags & M_STORE_FLAG;
205 virtual bool hasResultInterlock(MachineOpCode Opcode) const {
210 // Latencies for individual instructions and instruction pairs
212 virtual int minLatency(MachineOpCode Opcode) const {
213 return get(Opcode).latency;
216 virtual int maxLatency(MachineOpCode Opcode) const {
217 return get(Opcode).latency;
221 // Which operand holds an immediate constant? Returns -1 if none
223 virtual int getImmedConstantPos(MachineOpCode Opcode) const {
224 return -1; // immediate position is machine specific, so say -1 == "none"
227 // Check if the specified constant fits in the immediate field
228 // of this machine instruction
230 virtual bool constantFitsInImmedField(MachineOpCode Opcode,
231 int64_t intValue) const;
233 // Return the largest positive constant that can be held in the IMMED field
234 // of this machine instruction.
235 // isSignExtended is set to true if the value is sign-extended before use
236 // (this is true for all immediate fields in SPARC instructions).
237 // Return 0 if the instruction has no IMMED field.
239 virtual uint64_t maxImmedConstant(MachineOpCode Opcode,
240 bool &isSignExtended) const {
241 isSignExtended = get(Opcode).immedIsSignExtended;
242 return get(Opcode).maxImmedConst;
246 } // End llvm namespace