1 //===- ConstantHandling.cpp - Implement ConstantHandling.h ----------------===//
3 // This file implements the various intrinsic operations, on constant values.
5 //===----------------------------------------------------------------------===//
7 #include "llvm/ConstantHandling.h"
8 #include "llvm/iPHINode.h"
11 AnnotationID ConstRules::AID(AnnotationManager::getID("opt::ConstRules",
14 // ConstantFoldInstruction - Attempt to constant fold the specified instruction.
15 // If successful, the constant result is returned, if not, null is returned.
17 Constant *ConstantFoldInstruction(Instruction *I) {
18 if (PHINode *PN = dyn_cast<PHINode>(I)) {
19 if (PN->getNumIncomingValues() == 0)
20 return Constant::getNullValue(PN->getType());
22 Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0));
23 if (Result == 0) return 0;
25 // Handle PHI nodes specially here...
26 for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
27 if (PN->getIncomingValue(i) != Result)
28 return 0; // Not all the same incoming constants...
30 // If we reach here, all incoming values are the same constant.
37 if (I->getNumOperands() != 0) { // Get first operand if it's a constant...
38 Op0 = dyn_cast<Constant>(I->getOperand(0));
39 if (Op0 == 0) return 0; // Not a constant?, can't fold
41 if (I->getNumOperands() != 1) { // Get second operand if it's a constant...
42 Op1 = dyn_cast<Constant>(I->getOperand(1));
43 if (Op1 == 0) return 0; // Not a constant?, can't fold
47 switch (I->getOpcode()) {
48 case Instruction::Cast:
49 return ConstRules::get(*Op0)->castTo(Op0, I->getType());
50 case Instruction::Add: return *Op0 + *Op1;
51 case Instruction::Sub: return *Op0 - *Op1;
52 case Instruction::Mul: return *Op0 * *Op1;
53 case Instruction::Div: return *Op0 / *Op1;
54 case Instruction::Rem: return *Op0 % *Op1;
55 case Instruction::And: return *Op0 & *Op1;
56 case Instruction::Or: return *Op0 | *Op1;
57 case Instruction::Xor: return *Op0 ^ *Op1;
59 case Instruction::SetEQ: return *Op0 == *Op1;
60 case Instruction::SetNE: return *Op0 != *Op1;
61 case Instruction::SetLE: return *Op0 <= *Op1;
62 case Instruction::SetGE: return *Op0 >= *Op1;
63 case Instruction::SetLT: return *Op0 < *Op1;
64 case Instruction::SetGT: return *Op0 > *Op1;
65 case Instruction::Shl: return *Op0 << *Op1;
66 case Instruction::Shr: return *Op0 >> *Op1;
72 Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy) {
73 return ConstRules::get(*V)->castTo(V, DestTy);
76 Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1,
79 case Instruction::Add: return *V1 + *V2;
80 case Instruction::Sub: return *V1 - *V2;
81 case Instruction::Mul: return *V1 * *V2;
82 case Instruction::Div: return *V1 / *V2;
83 case Instruction::Rem: return *V1 % *V2;
84 case Instruction::And: return *V1 & *V2;
85 case Instruction::Or: return *V1 | *V2;
86 case Instruction::Xor: return *V1 ^ *V2;
88 case Instruction::SetEQ: return *V1 == *V2;
89 case Instruction::SetNE: return *V1 != *V2;
90 case Instruction::SetLE: return *V1 <= *V2;
91 case Instruction::SetGE: return *V1 >= *V2;
92 case Instruction::SetLT: return *V1 < *V2;
93 case Instruction::SetGT: return *V1 > *V2;
98 Constant *ConstantFoldShiftInstruction(unsigned Opcode, const Constant *V1,
101 case Instruction::Shl: return *V1 << *V2;
102 case Instruction::Shr: return *V1 >> *V2;
108 //===----------------------------------------------------------------------===//
109 // TemplateRules Class
110 //===----------------------------------------------------------------------===//
112 // TemplateRules - Implement a subclass of ConstRules that provides all
113 // operations as noops. All other rules classes inherit from this class so
114 // that if functionality is needed in the future, it can simply be added here
115 // and to ConstRules without changing anything else...
117 // This class also provides subclasses with typesafe implementations of methods
118 // so that don't have to do type casting.
120 template<class ArgType, class SubClassName>
121 class TemplateRules : public ConstRules {
123 //===--------------------------------------------------------------------===//
124 // Redirecting functions that cast to the appropriate types
125 //===--------------------------------------------------------------------===//
127 virtual Constant *add(const Constant *V1, const Constant *V2) const {
128 return SubClassName::Add((const ArgType *)V1, (const ArgType *)V2);
130 virtual Constant *sub(const Constant *V1, const Constant *V2) const {
131 return SubClassName::Sub((const ArgType *)V1, (const ArgType *)V2);
133 virtual Constant *mul(const Constant *V1, const Constant *V2) const {
134 return SubClassName::Mul((const ArgType *)V1, (const ArgType *)V2);
136 virtual Constant *div(const Constant *V1, const Constant *V2) const {
137 return SubClassName::Div((const ArgType *)V1, (const ArgType *)V2);
139 virtual Constant *rem(const Constant *V1, const Constant *V2) const {
140 return SubClassName::Rem((const ArgType *)V1, (const ArgType *)V2);
142 virtual Constant *op_and(const Constant *V1, const Constant *V2) const {
143 return SubClassName::And((const ArgType *)V1, (const ArgType *)V2);
145 virtual Constant *op_or(const Constant *V1, const Constant *V2) const {
146 return SubClassName::Or((const ArgType *)V1, (const ArgType *)V2);
148 virtual Constant *op_xor(const Constant *V1, const Constant *V2) const {
149 return SubClassName::Xor((const ArgType *)V1, (const ArgType *)V2);
151 virtual Constant *shl(const Constant *V1, const Constant *V2) const {
152 return SubClassName::Shl((const ArgType *)V1, (const ArgType *)V2);
154 virtual Constant *shr(const Constant *V1, const Constant *V2) const {
155 return SubClassName::Shr((const ArgType *)V1, (const ArgType *)V2);
158 virtual ConstantBool *lessthan(const Constant *V1,
159 const Constant *V2) const {
160 return SubClassName::LessThan((const ArgType *)V1, (const ArgType *)V2);
163 // Casting operators. ick
164 virtual ConstantBool *castToBool(const Constant *V) const {
165 return SubClassName::CastToBool((const ArgType*)V);
167 virtual ConstantSInt *castToSByte(const Constant *V) const {
168 return SubClassName::CastToSByte((const ArgType*)V);
170 virtual ConstantUInt *castToUByte(const Constant *V) const {
171 return SubClassName::CastToUByte((const ArgType*)V);
173 virtual ConstantSInt *castToShort(const Constant *V) const {
174 return SubClassName::CastToShort((const ArgType*)V);
176 virtual ConstantUInt *castToUShort(const Constant *V) const {
177 return SubClassName::CastToUShort((const ArgType*)V);
179 virtual ConstantSInt *castToInt(const Constant *V) const {
180 return SubClassName::CastToInt((const ArgType*)V);
182 virtual ConstantUInt *castToUInt(const Constant *V) const {
183 return SubClassName::CastToUInt((const ArgType*)V);
185 virtual ConstantSInt *castToLong(const Constant *V) const {
186 return SubClassName::CastToLong((const ArgType*)V);
188 virtual ConstantUInt *castToULong(const Constant *V) const {
189 return SubClassName::CastToULong((const ArgType*)V);
191 virtual ConstantFP *castToFloat(const Constant *V) const {
192 return SubClassName::CastToFloat((const ArgType*)V);
194 virtual ConstantFP *castToDouble(const Constant *V) const {
195 return SubClassName::CastToDouble((const ArgType*)V);
197 virtual ConstantPointer *castToPointer(const Constant *V,
198 const PointerType *Ty) const {
199 return SubClassName::CastToPointer((const ArgType*)V, Ty);
202 //===--------------------------------------------------------------------===//
203 // Default "noop" implementations
204 //===--------------------------------------------------------------------===//
206 static Constant *Add(const ArgType *V1, const ArgType *V2) { return 0; }
207 static Constant *Sub(const ArgType *V1, const ArgType *V2) { return 0; }
208 static Constant *Mul(const ArgType *V1, const ArgType *V2) { return 0; }
209 static Constant *Div(const ArgType *V1, const ArgType *V2) { return 0; }
210 static Constant *Rem(const ArgType *V1, const ArgType *V2) { return 0; }
211 static Constant *And(const ArgType *V1, const ArgType *V2) { return 0; }
212 static Constant *Or (const ArgType *V1, const ArgType *V2) { return 0; }
213 static Constant *Xor(const ArgType *V1, const ArgType *V2) { return 0; }
214 static Constant *Shl(const ArgType *V1, const ArgType *V2) { return 0; }
215 static Constant *Shr(const ArgType *V1, const ArgType *V2) { return 0; }
216 static ConstantBool *LessThan(const ArgType *V1, const ArgType *V2) {
220 // Casting operators. ick
221 static ConstantBool *CastToBool (const Constant *V) { return 0; }
222 static ConstantSInt *CastToSByte (const Constant *V) { return 0; }
223 static ConstantUInt *CastToUByte (const Constant *V) { return 0; }
224 static ConstantSInt *CastToShort (const Constant *V) { return 0; }
225 static ConstantUInt *CastToUShort(const Constant *V) { return 0; }
226 static ConstantSInt *CastToInt (const Constant *V) { return 0; }
227 static ConstantUInt *CastToUInt (const Constant *V) { return 0; }
228 static ConstantSInt *CastToLong (const Constant *V) { return 0; }
229 static ConstantUInt *CastToULong (const Constant *V) { return 0; }
230 static ConstantFP *CastToFloat (const Constant *V) { return 0; }
231 static ConstantFP *CastToDouble(const Constant *V) { return 0; }
232 static ConstantPointer *CastToPointer(const Constant *,
233 const PointerType *) {return 0;}
238 //===----------------------------------------------------------------------===//
240 //===----------------------------------------------------------------------===//
242 // EmptyRules provides a concrete base class of ConstRules that does nothing
244 struct EmptyRules : public TemplateRules<Constant, EmptyRules> {
249 //===----------------------------------------------------------------------===//
251 //===----------------------------------------------------------------------===//
253 // BoolRules provides a concrete base class of ConstRules for the 'bool' type.
255 struct BoolRules : public TemplateRules<ConstantBool, BoolRules> {
257 static Constant *And(const ConstantBool *V1, const ConstantBool *V2) {
258 return ConstantBool::get(V1->getValue() & V2->getValue());
261 static Constant *Or(const ConstantBool *V1, const ConstantBool *V2) {
262 return ConstantBool::get(V1->getValue() | V2->getValue());
265 static Constant *Xor(const ConstantBool *V1, const ConstantBool *V2) {
266 return ConstantBool::get(V1->getValue() ^ V2->getValue());
271 //===----------------------------------------------------------------------===//
272 // PointerRules Class
273 //===----------------------------------------------------------------------===//
275 // PointerRules provides a concrete base class of ConstRules for pointer types
277 struct PointerRules : public TemplateRules<ConstantPointer, PointerRules> {
278 static ConstantBool *CastToBool (const Constant *V) {
279 if (V->isNullValue()) return ConstantBool::False;
280 return 0; // Can't const prop other types of pointers
282 static ConstantSInt *CastToSByte (const Constant *V) {
283 if (V->isNullValue()) return ConstantSInt::get(Type::SByteTy, 0);
284 return 0; // Can't const prop other types of pointers
286 static ConstantUInt *CastToUByte (const Constant *V) {
287 if (V->isNullValue()) return ConstantUInt::get(Type::UByteTy, 0);
288 return 0; // Can't const prop other types of pointers
290 static ConstantSInt *CastToShort (const Constant *V) {
291 if (V->isNullValue()) return ConstantSInt::get(Type::ShortTy, 0);
292 return 0; // Can't const prop other types of pointers
294 static ConstantUInt *CastToUShort(const Constant *V) {
295 if (V->isNullValue()) return ConstantUInt::get(Type::UShortTy, 0);
296 return 0; // Can't const prop other types of pointers
298 static ConstantSInt *CastToInt (const Constant *V) {
299 if (V->isNullValue()) return ConstantSInt::get(Type::IntTy, 0);
300 return 0; // Can't const prop other types of pointers
302 static ConstantUInt *CastToUInt (const Constant *V) {
303 if (V->isNullValue()) return ConstantUInt::get(Type::UIntTy, 0);
304 return 0; // Can't const prop other types of pointers
306 static ConstantSInt *CastToLong (const Constant *V) {
307 if (V->isNullValue()) return ConstantSInt::get(Type::LongTy, 0);
308 return 0; // Can't const prop other types of pointers
310 static ConstantUInt *CastToULong (const Constant *V) {
311 if (V->isNullValue()) return ConstantUInt::get(Type::ULongTy, 0);
312 return 0; // Can't const prop other types of pointers
314 static ConstantFP *CastToFloat (const Constant *V) {
315 if (V->isNullValue()) return ConstantFP::get(Type::FloatTy, 0);
316 return 0; // Can't const prop other types of pointers
318 static ConstantFP *CastToDouble(const Constant *V) {
319 if (V->isNullValue()) return ConstantFP::get(Type::DoubleTy, 0);
320 return 0; // Can't const prop other types of pointers
323 static ConstantPointer *CastToPointer(const ConstantPointer *V,
324 const PointerType *PTy) {
325 if (V->getType() == PTy)
326 return const_cast<ConstantPointer*>(V); // Allow cast %PTy %ptr to %PTy
327 if (V->isNullValue())
328 return ConstantPointerNull::get(PTy);
329 return 0; // Can't const prop other types of pointers
334 //===----------------------------------------------------------------------===//
336 //===----------------------------------------------------------------------===//
338 // DirectRules provides a concrete base classes of ConstRules for a variety of
339 // different types. This allows the C++ compiler to automatically generate our
340 // constant handling operations in a typesafe and accurate manner.
342 template<class ConstantClass, class BuiltinType, Type **Ty, class SuperClass>
343 struct DirectRules : public TemplateRules<ConstantClass, SuperClass> {
344 static Constant *Add(const ConstantClass *V1, const ConstantClass *V2) {
345 BuiltinType R = (BuiltinType)V1->getValue() + (BuiltinType)V2->getValue();
346 return ConstantClass::get(*Ty, R);
349 static Constant *Sub(const ConstantClass *V1, const ConstantClass *V2) {
350 BuiltinType R = (BuiltinType)V1->getValue() - (BuiltinType)V2->getValue();
351 return ConstantClass::get(*Ty, R);
354 static Constant *Mul(const ConstantClass *V1, const ConstantClass *V2) {
355 BuiltinType R = (BuiltinType)V1->getValue() * (BuiltinType)V2->getValue();
356 return ConstantClass::get(*Ty, R);
359 static Constant *Div(const ConstantClass *V1, const ConstantClass *V2) {
360 if (V2->isNullValue()) return 0;
361 BuiltinType R = (BuiltinType)V1->getValue() / (BuiltinType)V2->getValue();
362 return ConstantClass::get(*Ty, R);
365 static ConstantBool *LessThan(const ConstantClass *V1,
366 const ConstantClass *V2) {
367 bool R = (BuiltinType)V1->getValue() < (BuiltinType)V2->getValue();
368 return ConstantBool::get(R);
371 static ConstantPointer *CastToPointer(const ConstantClass *V,
372 const PointerType *PTy) {
373 if (V->isNullValue()) // Is it a FP or Integral null value?
374 return ConstantPointerNull::get(PTy);
375 return 0; // Can't const prop other types of pointers
378 // Casting operators. ick
379 #define DEF_CAST(TYPE, CLASS, CTYPE) \
380 static CLASS *CastTo##TYPE (const ConstantClass *V) { \
381 return CLASS::get(Type::TYPE##Ty, (CTYPE)(BuiltinType)V->getValue()); \
384 DEF_CAST(Bool , ConstantBool, bool)
385 DEF_CAST(SByte , ConstantSInt, signed char)
386 DEF_CAST(UByte , ConstantUInt, unsigned char)
387 DEF_CAST(Short , ConstantSInt, signed short)
388 DEF_CAST(UShort, ConstantUInt, unsigned short)
389 DEF_CAST(Int , ConstantSInt, signed int)
390 DEF_CAST(UInt , ConstantUInt, unsigned int)
391 DEF_CAST(Long , ConstantSInt, int64_t)
392 DEF_CAST(ULong , ConstantUInt, uint64_t)
393 DEF_CAST(Float , ConstantFP , float)
394 DEF_CAST(Double, ConstantFP , double)
399 //===----------------------------------------------------------------------===//
400 // DirectIntRules Class
401 //===----------------------------------------------------------------------===//
403 // DirectIntRules provides implementations of functions that are valid on
404 // integer types, but not all types in general.
406 template <class ConstantClass, class BuiltinType, Type **Ty>
407 struct DirectIntRules
408 : public DirectRules<ConstantClass, BuiltinType, Ty,
409 DirectIntRules<ConstantClass, BuiltinType, Ty> > {
411 static Constant *Rem(const ConstantClass *V1,
412 const ConstantClass *V2) {
413 if (V2->isNullValue()) return 0;
414 BuiltinType R = (BuiltinType)V1->getValue() % (BuiltinType)V2->getValue();
415 return ConstantClass::get(*Ty, R);
418 static Constant *And(const ConstantClass *V1, const ConstantClass *V2) {
419 BuiltinType R = (BuiltinType)V1->getValue() & (BuiltinType)V2->getValue();
420 return ConstantClass::get(*Ty, R);
422 static Constant *Or(const ConstantClass *V1, const ConstantClass *V2) {
423 BuiltinType R = (BuiltinType)V1->getValue() | (BuiltinType)V2->getValue();
424 return ConstantClass::get(*Ty, R);
426 static Constant *Xor(const ConstantClass *V1, const ConstantClass *V2) {
427 BuiltinType R = (BuiltinType)V1->getValue() ^ (BuiltinType)V2->getValue();
428 return ConstantClass::get(*Ty, R);
431 static Constant *Shl(const ConstantClass *V1, const ConstantClass *V2) {
432 BuiltinType R = (BuiltinType)V1->getValue() << (BuiltinType)V2->getValue();
433 return ConstantClass::get(*Ty, R);
436 static Constant *Shr(const ConstantClass *V1, const ConstantClass *V2) {
437 BuiltinType R = (BuiltinType)V1->getValue() >> (BuiltinType)V2->getValue();
438 return ConstantClass::get(*Ty, R);
443 //===----------------------------------------------------------------------===//
444 // DirectFPRules Class
445 //===----------------------------------------------------------------------===//
447 // DirectFPRules provides implementations of functions that are valid on
448 // floating point types, but not all types in general.
450 template <class ConstantClass, class BuiltinType, Type **Ty>
452 : public DirectRules<ConstantClass, BuiltinType, Ty,
453 DirectFPRules<ConstantClass, BuiltinType, Ty> > {
454 static Constant *Rem(const ConstantClass *V1, const ConstantClass *V2) {
455 if (V2->isNullValue()) return 0;
456 BuiltinType Result = std::fmod((BuiltinType)V1->getValue(),
457 (BuiltinType)V2->getValue());
458 return ConstantClass::get(*Ty, Result);
463 //===----------------------------------------------------------------------===//
464 // DirectRules Subclasses
465 //===----------------------------------------------------------------------===//
467 // Given the DirectRules class we can now implement lots of types with little
468 // code. Thank goodness C++ compilers are great at stomping out layers of
469 // templates... can you imagine having to do this all by hand? (/me is lazy :)
472 // ConstRules::find - Return the constant rules that take care of the specified
475 Annotation *ConstRules::find(AnnotationID AID, const Annotable *TyA, void *) {
476 assert(AID == ConstRules::AID && "Bad annotation for factory!");
477 const Type *Ty = cast<Type>((const Value*)TyA);
479 switch (Ty->getPrimitiveID()) {
480 case Type::BoolTyID: return new BoolRules();
481 case Type::PointerTyID: return new PointerRules();
482 case Type::SByteTyID:
483 return new DirectIntRules<ConstantSInt, signed char , &Type::SByteTy>();
484 case Type::UByteTyID:
485 return new DirectIntRules<ConstantUInt, unsigned char , &Type::UByteTy>();
486 case Type::ShortTyID:
487 return new DirectIntRules<ConstantSInt, signed short, &Type::ShortTy>();
488 case Type::UShortTyID:
489 return new DirectIntRules<ConstantUInt, unsigned short, &Type::UShortTy>();
491 return new DirectIntRules<ConstantSInt, signed int , &Type::IntTy>();
493 return new DirectIntRules<ConstantUInt, unsigned int , &Type::UIntTy>();
495 return new DirectIntRules<ConstantSInt, int64_t , &Type::LongTy>();
496 case Type::ULongTyID:
497 return new DirectIntRules<ConstantUInt, uint64_t , &Type::ULongTy>();
498 case Type::FloatTyID:
499 return new DirectFPRules<ConstantFP , float , &Type::FloatTy>();
500 case Type::DoubleTyID:
501 return new DirectFPRules<ConstantFP , double , &Type::DoubleTy>();
503 return new EmptyRules();