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 "Support/DataTypes.h"
30 class MachineCodeForInstruction;
32 //---------------------------------------------------------------------------
33 // Data types used to define information about a single machine instruction
34 //---------------------------------------------------------------------------
36 typedef short MachineOpCode;
37 typedef unsigned InstrSchedClass;
39 //---------------------------------------------------------------------------
40 // struct TargetInstrDescriptor:
41 // Predefined information about each machine instruction.
42 // Designed to initialized statically.
45 const unsigned M_NOP_FLAG = 1 << 0;
46 const unsigned M_BRANCH_FLAG = 1 << 1;
47 const unsigned M_CALL_FLAG = 1 << 2;
48 const unsigned M_RET_FLAG = 1 << 3;
49 const unsigned M_CC_FLAG = 1 << 6;
50 const unsigned M_LOAD_FLAG = 1 << 10;
51 const unsigned M_STORE_FLAG = 1 << 12;
52 const unsigned M_DUMMY_PHI_FLAG = 1 << 13;
53 const unsigned M_PSEUDO_FLAG = 1 << 14; // Pseudo instruction
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 descSize; // 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 descSize,
93 unsigned numRealOpCodes);
94 virtual ~TargetInstrInfo();
96 // Invariant: All instruction sets use opcode #0 as the PHI instruction
99 unsigned getNumRealOpCodes() const { return numRealOpCodes; }
100 unsigned getNumTotalOpCodes() const { return descSize; }
102 /// get - Return the machine instruction descriptor that corresponds to the
103 /// specified instruction opcode.
105 const TargetInstrDescriptor& get(MachineOpCode opCode) const {
106 assert(opCode >= 0 && opCode < (int)descSize);
110 const char *getName(MachineOpCode opCode) const {
111 return get(opCode).Name;
114 int getNumOperands(MachineOpCode opCode) const {
115 return get(opCode).numOperands;
119 InstrSchedClass getSchedClass(MachineOpCode opCode) const {
120 return get(opCode).schedClass;
123 const unsigned *getImplicitUses(MachineOpCode opCode) const {
124 return get(opCode).ImplicitUses;
127 const unsigned *getImplicitDefs(MachineOpCode opCode) const {
128 return get(opCode).ImplicitDefs;
133 // Query instruction class flags according to the machine-independent
134 // flags listed above.
136 bool isReturn(MachineOpCode opCode) const {
137 return get(opCode).Flags & M_RET_FLAG;
140 bool isPseudoInstr(MachineOpCode opCode) const {
141 return get(opCode).Flags & M_PSEUDO_FLAG;
143 bool isTwoAddrInstr(MachineOpCode opCode) const {
144 return get(opCode).Flags & M_2_ADDR_FLAG;
146 bool isTerminatorInstr(unsigned Opcode) const {
147 return get(Opcode).Flags & M_TERMINATOR_FLAG;
151 // Return true if the instruction is a register to register move and
152 // leave the source and dest operands in the passed parameters.
154 virtual bool isMoveInstr(const MachineInstr& MI,
156 unsigned& destReg) const {
163 //-------------------------------------------------------------------------
164 // Code generation support for creating individual machine instructions
166 // WARNING: These methods are Sparc specific
168 // DO NOT USE ANY OF THESE METHODS THEY ARE DEPRECATED!
170 //-------------------------------------------------------------------------
172 int getResultPos(MachineOpCode opCode) const {
173 return get(opCode).resultPos;
175 unsigned getNumDelaySlots(MachineOpCode opCode) const {
176 return get(opCode).numDelaySlots;
178 bool isCCInstr(MachineOpCode opCode) const {
179 return get(opCode).Flags & M_CC_FLAG;
181 bool isNop(MachineOpCode opCode) const {
182 return get(opCode).Flags & M_NOP_FLAG;
184 bool isBranch(MachineOpCode opCode) const {
185 return get(opCode).Flags & M_BRANCH_FLAG;
187 bool isCall(MachineOpCode opCode) const {
188 return get(opCode).Flags & M_CALL_FLAG;
190 bool isLoad(MachineOpCode opCode) const {
191 return get(opCode).Flags & M_LOAD_FLAG;
193 bool isStore(MachineOpCode opCode) const {
194 return get(opCode).Flags & M_STORE_FLAG;
196 bool isDummyPhiInstr(MachineOpCode opCode) const {
197 return get(opCode).Flags & M_DUMMY_PHI_FLAG;
199 // Check if an instruction can be issued before its operands are ready,
200 // or if a subsequent instruction that uses its result can be issued
201 // before the results are ready.
202 // Default to true since most instructions on many architectures allow this.
204 virtual bool hasOperandInterlock(MachineOpCode opCode) const {
207 virtual bool hasResultInterlock(MachineOpCode opCode) const {
212 // Latencies for individual instructions and instruction pairs
214 virtual int minLatency(MachineOpCode opCode) const {
215 return get(opCode).latency;
218 virtual int maxLatency(MachineOpCode opCode) const {
219 return get(opCode).latency;
223 // Which operand holds an immediate constant? Returns -1 if none
225 virtual int getImmedConstantPos(MachineOpCode opCode) const {
226 return -1; // immediate position is machine specific, so say -1 == "none"
229 // Check if the specified constant fits in the immediate field
230 // of this machine instruction
232 virtual bool constantFitsInImmedField(MachineOpCode opCode,
233 int64_t intValue) const;
235 // Return the largest positive constant that can be held in the IMMED field
236 // of this machine instruction.
237 // isSignExtended is set to true if the value is sign-extended before use
238 // (this is true for all immediate fields in SPARC instructions).
239 // Return 0 if the instruction has no IMMED field.
241 virtual uint64_t maxImmedConstant(MachineOpCode opCode,
242 bool &isSignExtended) const {
243 isSignExtended = get(opCode).immedIsSignExtended;
244 return get(opCode).maxImmedConst;
247 //-------------------------------------------------------------------------
248 // Queries about representation of LLVM quantities (e.g., constants)
249 //-------------------------------------------------------------------------
251 /// ConstantTypeMustBeLoaded - Test if this type of constant must be loaded
252 /// from memory into a register, i.e., cannot be set bitwise in register and
253 /// cannot use immediate fields of instructions. Note that this only makes
254 /// sense for primitive types.
256 virtual bool ConstantTypeMustBeLoaded(const Constant* CV) const;
258 // Test if this constant may not fit in the immediate field of the
259 // machine instructions (probably) generated for this instruction.
261 virtual bool ConstantMayNotFitInImmedField(const Constant* CV,
262 const Instruction* I) const {
263 return true; // safe but very conservative
266 // Get certain common op codes for the current target. this and all the
267 // Create* methods below should be moved to a machine code generation class
269 virtual MachineOpCode getNOPOpCode() const { abort(); }
271 // Get the value of an integral constant in the form that must
272 // be put into the machine register. The specified constant is interpreted
273 // as (i.e., converted if necessary to) the specified destination type. The
274 // result is always returned as an uint64_t, since the representation of
275 // int64_t and uint64_t are identical. The argument can be any known const.
277 // isValidConstant is set to true if a valid constant was found.
279 virtual uint64_t ConvertConstantToIntType(const TargetMachine &target,
281 const Type *destType,
282 bool &isValidConstant) const {
286 // Create an instruction sequence to put the constant `val' into
287 // the virtual register `dest'. `val' may be a Constant or a
288 // GlobalValue, viz., the constant address of a global variable or function.
289 // The generated instructions are returned in `mvec'.
290 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
291 // Symbolic constants or constants that must be accessed from memory
292 // are added to the constant pool via MachineFunction::get(F).
294 virtual void CreateCodeToLoadConst(const TargetMachine& target,
298 std::vector<MachineInstr*>& mvec,
299 MachineCodeForInstruction& mcfi) const {
303 // Create an instruction sequence to copy an integer value `val'
304 // to a floating point value `dest' by copying to memory and back.
305 // val must be an integral type. dest must be a Float or Double.
306 // The generated instructions are returned in `mvec'.
307 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
308 // Any stack space required is allocated via mcff.
310 virtual void CreateCodeToCopyIntToFloat(const TargetMachine& target,
314 std::vector<MachineInstr*>& mvec,
315 MachineCodeForInstruction& MI) const {
319 // Similarly, create an instruction sequence to copy an FP value
320 // `val' to an integer value `dest' by copying to memory and back.
321 // The generated instructions are returned in `mvec'.
322 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
323 // Any stack space required is allocated via mcff.
325 virtual void CreateCodeToCopyFloatToInt(const TargetMachine& target,
329 std::vector<MachineInstr*>& mvec,
330 MachineCodeForInstruction& MI) const {
334 // Create instruction(s) to copy src to dest, for arbitrary types
335 // The generated instructions are returned in `mvec'.
336 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
337 // Any stack space required is allocated via mcff.
339 virtual void CreateCopyInstructionsByType(const TargetMachine& target,
343 std::vector<MachineInstr*>& mvec,
344 MachineCodeForInstruction& MI) const {
348 // Create instruction sequence to produce a sign-extended register value
349 // from an arbitrary sized value (sized in bits, not bytes).
350 // The generated instructions are appended to `mvec'.
351 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
352 // Any stack space required is allocated via mcff.
354 virtual void CreateSignExtensionInstructions(const TargetMachine& target,
359 std::vector<MachineInstr*>& mvec,
360 MachineCodeForInstruction& MI) const {
364 // Create instruction sequence to produce a zero-extended register value
365 // from an arbitrary sized value (sized in bits, not bytes).
366 // The generated instructions are appended to `mvec'.
367 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
368 // Any stack space required is allocated via mcff.
370 virtual void CreateZeroExtensionInstructions(const TargetMachine& target,
374 unsigned srcSizeInBits,
375 std::vector<MachineInstr*>& mvec,
376 MachineCodeForInstruction& mcfi) const {
381 } // End llvm namespace