1 //===-- llvm/Target/TargetInstrInfo.h - Instruction Info --------*- C++ -*-===//
3 // This file describes the target machine instructions to the code generator.
5 //===----------------------------------------------------------------------===//
7 #ifndef LLVM_TARGET_TARGETINSTRINFO_H
8 #define LLVM_TARGET_TARGETINSTRINFO_H
10 #include "Support/DataTypes.h"
21 class MachineCodeForInstruction;
23 //---------------------------------------------------------------------------
24 // Data types used to define information about a single machine instruction
25 //---------------------------------------------------------------------------
27 typedef int MachineOpCode;
28 typedef unsigned InstrSchedClass;
30 const MachineOpCode INVALID_MACHINE_OPCODE = -1;
33 //---------------------------------------------------------------------------
34 // struct TargetInstrDescriptor:
35 // Predefined information about each machine instruction.
36 // Designed to initialized statically.
39 const unsigned M_NOP_FLAG = 1 << 0;
40 const unsigned M_BRANCH_FLAG = 1 << 1;
41 const unsigned M_CALL_FLAG = 1 << 2;
42 const unsigned M_RET_FLAG = 1 << 3;
43 const unsigned M_ARITH_FLAG = 1 << 4;
44 const unsigned M_CC_FLAG = 1 << 6;
45 const unsigned M_LOGICAL_FLAG = 1 << 6;
46 const unsigned M_INT_FLAG = 1 << 7;
47 const unsigned M_FLOAT_FLAG = 1 << 8;
48 const unsigned M_CONDL_FLAG = 1 << 9;
49 const unsigned M_LOAD_FLAG = 1 << 10;
50 const unsigned M_PREFETCH_FLAG = 1 << 11;
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 IMMMED 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;
118 int getResultPos(MachineOpCode opCode) const {
119 return get(opCode).resultPos;
122 unsigned getNumDelaySlots(MachineOpCode opCode) const {
123 return get(opCode).numDelaySlots;
126 InstrSchedClass getSchedClass(MachineOpCode opCode) const {
127 return get(opCode).schedClass;
130 const unsigned *getImplicitUses(MachineOpCode opCode) const {
131 return get(opCode).ImplicitUses;
134 const unsigned *getImplicitDefs(MachineOpCode opCode) const {
135 return get(opCode).ImplicitDefs;
139 // Query instruction class flags according to the machine-independent
140 // flags listed above.
142 bool isNop(MachineOpCode opCode) const {
143 return get(opCode).Flags & M_NOP_FLAG;
145 bool isBranch(MachineOpCode opCode) const {
146 return get(opCode).Flags & M_BRANCH_FLAG;
148 bool isCall(MachineOpCode opCode) const {
149 return get(opCode).Flags & M_CALL_FLAG;
151 bool isReturn(MachineOpCode opCode) const {
152 return get(opCode).Flags & M_RET_FLAG;
154 bool isControlFlow(MachineOpCode opCode) const {
155 return get(opCode).Flags & M_BRANCH_FLAG
156 || get(opCode).Flags & M_CALL_FLAG
157 || get(opCode).Flags & M_RET_FLAG;
159 bool isArith(MachineOpCode opCode) const {
160 return get(opCode).Flags & M_ARITH_FLAG;
162 bool isCCInstr(MachineOpCode opCode) const {
163 return get(opCode).Flags & M_CC_FLAG;
165 bool isLogical(MachineOpCode opCode) const {
166 return get(opCode).Flags & M_LOGICAL_FLAG;
168 bool isIntInstr(MachineOpCode opCode) const {
169 return get(opCode).Flags & M_INT_FLAG;
171 bool isFloatInstr(MachineOpCode opCode) const {
172 return get(opCode).Flags & M_FLOAT_FLAG;
174 bool isConditional(MachineOpCode opCode) const {
175 return get(opCode).Flags & M_CONDL_FLAG;
177 bool isLoad(MachineOpCode opCode) const {
178 return get(opCode).Flags & M_LOAD_FLAG;
180 bool isPrefetch(MachineOpCode opCode) const {
181 return get(opCode).Flags & M_PREFETCH_FLAG;
183 bool isLoadOrPrefetch(MachineOpCode opCode) const {
184 return get(opCode).Flags & M_LOAD_FLAG
185 || get(opCode).Flags & M_PREFETCH_FLAG;
187 bool isStore(MachineOpCode opCode) const {
188 return get(opCode).Flags & M_STORE_FLAG;
190 bool isMemoryAccess(MachineOpCode opCode) const {
191 return get(opCode).Flags & M_LOAD_FLAG
192 || get(opCode).Flags & M_PREFETCH_FLAG
193 || get(opCode).Flags & M_STORE_FLAG;
195 bool isDummyPhiInstr(MachineOpCode opCode) const {
196 return get(opCode).Flags & M_DUMMY_PHI_FLAG;
198 bool isPseudoInstr(MachineOpCode opCode) const {
199 return get(opCode).Flags & M_PSEUDO_FLAG;
201 bool isTwoAddrInstr(MachineOpCode opCode) const {
202 return get(opCode).Flags & M_2_ADDR_FLAG;
204 bool isTerminatorInstr(unsigned Opcode) const {
205 return get(Opcode).Flags & M_TERMINATOR_FLAG;
208 // Check if an instruction can be issued before its operands are ready,
209 // or if a subsequent instruction that uses its result can be issued
210 // before the results are ready.
211 // Default to true since most instructions on many architectures allow this.
213 virtual bool hasOperandInterlock(MachineOpCode opCode) const {
217 virtual bool hasResultInterlock(MachineOpCode opCode) const {
222 // Latencies for individual instructions and instruction pairs
224 virtual int minLatency(MachineOpCode opCode) const {
225 return get(opCode).latency;
228 virtual int maxLatency(MachineOpCode opCode) const {
229 return get(opCode).latency;
233 // Which operand holds an immediate constant? Returns -1 if none
235 virtual int getImmedConstantPos(MachineOpCode opCode) const {
236 return -1; // immediate position is machine specific, so say -1 == "none"
239 // Check if the specified constant fits in the immediate field
240 // of this machine instruction
242 virtual bool constantFitsInImmedField(MachineOpCode opCode,
243 int64_t intValue) const;
245 // Return the largest +ve constant that can be held in the IMMMED field
246 // of this machine instruction.
247 // isSignExtended is set to true if the value is sign-extended before use
248 // (this is true for all immediate fields in SPARC instructions).
249 // Return 0 if the instruction has no IMMED field.
251 virtual uint64_t maxImmedConstant(MachineOpCode opCode,
252 bool &isSignExtended) const {
253 isSignExtended = get(opCode).immedIsSignExtended;
254 return get(opCode).maxImmedConst;
257 //-------------------------------------------------------------------------
258 // Queries about representation of LLVM quantities (e.g., constants)
259 //-------------------------------------------------------------------------
261 /// ConstantTypeMustBeLoaded - Test if this type of constant must be loaded
262 /// from memory into a register, i.e., cannot be set bitwise in register and
263 /// cannot use immediate fields of instructions. Note that this only makes
264 /// sense for primitive types.
266 virtual bool ConstantTypeMustBeLoaded(const Constant* CV) const;
268 // Test if this constant may not fit in the immediate field of the
269 // machine instructions (probably) generated for this instruction.
271 virtual bool ConstantMayNotFitInImmedField(const Constant* CV,
272 const Instruction* I) const {
273 return true; // safe but very conservative
277 /// createNOPinstr - returns the target's implementation of NOP, which is
278 /// usually a pseudo-instruction, implemented by a degenerate version of
279 /// another instruction, e.g. X86: xchg ax, ax; SparcV9: sethi g0, 0
281 virtual MachineInstr* createNOPinstr() const = 0;
283 /// isNOPinstr - not having a special NOP opcode, we need to know if a given
284 /// instruction is interpreted as an `official' NOP instr, i.e., there may be
285 /// more than one way to `do nothing' but only one canonical way to slack off.
287 virtual bool isNOPinstr(const MachineInstr &MI) const = 0;
289 //-------------------------------------------------------------------------
290 // Code generation support for creating individual machine instructions
292 // WARNING: These methods are Sparc specific
294 //-------------------------------------------------------------------------
296 // Get certain common op codes for the current target. this and all the
297 // Create* methods below should be moved to a machine code generation class
299 virtual MachineOpCode getNOPOpCode() const { abort(); }
301 // Get the value of an integral constant in the form that must
302 // be put into the machine register. The specified constant is interpreted
303 // as (i.e., converted if necessary to) the specified destination type. The
304 // result is always returned as an uint64_t, since the representation of
305 // int64_t and uint64_t are identical. The argument can be any known const.
307 // isValidConstant is set to true if a valid constant was found.
309 virtual uint64_t ConvertConstantToIntType(const TargetMachine &target,
311 const Type *destType,
312 bool &isValidConstant) const {
316 // Create an instruction sequence to put the constant `val' into
317 // the virtual register `dest'. `val' may be a Constant or a
318 // GlobalValue, viz., the constant address of a global variable or function.
319 // The generated instructions are returned in `mvec'.
320 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
321 // Symbolic constants or constants that must be accessed from memory
322 // are added to the constant pool via MachineFunction::get(F).
324 virtual void CreateCodeToLoadConst(const TargetMachine& target,
328 std::vector<MachineInstr*>& mvec,
329 MachineCodeForInstruction& mcfi) const {
333 // Create an instruction sequence to copy an integer value `val'
334 // to a floating point value `dest' by copying to memory and back.
335 // val must be an integral type. dest must be a Float or Double.
336 // The generated instructions are returned in `mvec'.
337 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
338 // Any stack space required is allocated via mcff.
340 virtual void CreateCodeToCopyIntToFloat(const TargetMachine& target,
344 std::vector<MachineInstr*>& mvec,
345 MachineCodeForInstruction& MI) const {
349 // Similarly, create an instruction sequence to copy an FP value
350 // `val' to an integer value `dest' by copying to memory and back.
351 // The generated instructions are returned in `mvec'.
352 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
353 // Any stack space required is allocated via mcff.
355 virtual void CreateCodeToCopyFloatToInt(const TargetMachine& target,
359 std::vector<MachineInstr*>& mvec,
360 MachineCodeForInstruction& MI) const {
364 // Create instruction(s) to copy src to dest, for arbitrary types
365 // The generated instructions are returned in `mvec'.
366 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
367 // Any stack space required is allocated via mcff.
369 virtual void CreateCopyInstructionsByType(const TargetMachine& target,
373 std::vector<MachineInstr*>& mvec,
374 MachineCodeForInstruction& MI) const {
378 // Create instruction sequence to produce a sign-extended register value
379 // from an arbitrary sized value (sized in bits, not bytes).
380 // The generated instructions are appended to `mvec'.
381 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
382 // Any stack space required is allocated via mcff.
384 virtual void CreateSignExtensionInstructions(const TargetMachine& target,
389 std::vector<MachineInstr*>& mvec,
390 MachineCodeForInstruction& MI) const {
394 // Create instruction sequence to produce a zero-extended register value
395 // from an arbitrary sized value (sized in bits, not bytes).
396 // The generated instructions are appended to `mvec'.
397 // Any temp. registers (TmpInstruction) created are recorded in mcfi.
398 // Any stack space required is allocated via mcff.
400 virtual void CreateZeroExtensionInstructions(const TargetMachine& target,
404 unsigned srcSizeInBits,
405 std::vector<MachineInstr*>& mvec,
406 MachineCodeForInstruction& mcfi) const {