1 //===- ExprTypeConvert.cpp - Code to change an LLVM Expr Type ---------------=//
3 // This file implements the part of level raising that checks to see if it is
4 // possible to coerce an entire expression tree into a different type. If
5 // convertable, other routines from this file will do the conversion.
7 //===----------------------------------------------------------------------===//
9 #include "TransformInternals.h"
10 #include "llvm/iOther.h"
11 #include "llvm/iPHINode.h"
12 #include "llvm/iMemory.h"
13 #include "llvm/ConstantHandling.h"
14 #include "llvm/Analysis/Expressions.h"
15 #include "Support/STLExtras.h"
16 #include "Support/StatisticReporter.h"
21 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
22 ValueTypeCache &ConvertedTypes);
24 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
27 // AllIndicesZero - Return true if all of the indices of the specified memory
28 // access instruction are zero, indicating an effectively nil offset to the
31 static bool AllIndicesZero(const MemAccessInst *MAI) {
32 for (User::const_op_iterator S = MAI->idx_begin(), E = MAI->idx_end();
34 if (!isa<Constant>(S->get()) || !cast<Constant>(S->get())->isNullValue())
40 // Peephole Malloc instructions: we take a look at the use chain of the
41 // malloc instruction, and try to find out if the following conditions hold:
42 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
43 // 2. The only users of the malloc are cast & add instructions
44 // 3. Of the cast instructions, there is only one destination pointer type
45 // [RTy] where the size of the pointed to object is equal to the number
46 // of bytes allocated.
48 // If these conditions hold, we convert the malloc to allocate an [RTy]
49 // element. TODO: This comment is out of date WRT arrays
51 static bool MallocConvertableToType(MallocInst *MI, const Type *Ty,
52 ValueTypeCache &CTMap) {
53 if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
55 // Deal with the type to allocate, not the pointer type...
56 Ty = cast<PointerType>(Ty)->getElementType();
57 if (!Ty->isSized()) return false; // Can only alloc something with a size
59 // Analyze the number of bytes allocated...
60 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
62 // Get information about the base datatype being allocated, before & after
63 int ReqTypeSize = TD.getTypeSize(Ty);
64 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
66 // Must have a scale or offset to analyze it...
67 if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
69 // Get the offset and scale of the allocation...
70 int OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
71 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
73 // The old type might not be of unit size, take old size into consideration
75 int Offset = OffsetVal * OldTypeSize;
76 int Scale = ScaleVal * OldTypeSize;
78 // In order to be successful, both the scale and the offset must be a multiple
79 // of the requested data type's size.
81 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
82 Scale/ReqTypeSize*ReqTypeSize != Scale)
83 return false; // Nope.
88 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
89 const std::string &Name,
91 BasicBlock *BB = MI->getParent();
92 BasicBlock::iterator It = BB->end();
94 // Analyze the number of bytes allocated...
95 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
97 const PointerType *AllocTy = cast<PointerType>(Ty);
98 const Type *ElType = AllocTy->getElementType();
100 unsigned DataSize = TD.getTypeSize(ElType);
101 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
103 // Get the offset and scale coefficients that we are allocating...
104 int OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
105 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
107 // The old type might not be of unit size, take old size into consideration
109 unsigned Offset = (unsigned)OffsetVal * OldTypeSize / DataSize;
110 unsigned Scale = (unsigned)ScaleVal * OldTypeSize / DataSize;
112 // Locate the malloc instruction, because we may be inserting instructions
115 // If we have a scale, apply it first...
117 // Expr.Var is not neccesarily unsigned right now, insert a cast now.
118 if (Expr.Var->getType() != Type::UIntTy) {
119 Instruction *CI = new CastInst(Expr.Var, Type::UIntTy);
120 if (Expr.Var->hasName()) CI->setName(Expr.Var->getName()+"-uint");
121 It = ++BB->getInstList().insert(It, CI);
127 BinaryOperator::create(Instruction::Mul, Expr.Var,
128 ConstantUInt::get(Type::UIntTy, Scale));
129 if (Expr.Var->hasName()) ScI->setName(Expr.Var->getName()+"-scl");
130 It = ++BB->getInstList().insert(It, ScI);
135 // If we are not scaling anything, just make the offset be the "var"...
136 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
137 Offset = 0; Scale = 1;
140 // If we have an offset now, add it in...
142 assert(Expr.Var && "Var must be nonnull by now!");
145 BinaryOperator::create(Instruction::Add, Expr.Var,
146 ConstantUInt::get(Type::UIntTy, Offset));
147 if (Expr.Var->hasName()) AddI->setName(Expr.Var->getName()+"-off");
148 It = ++BB->getInstList().insert(It, AddI);
152 Instruction *NewI = new MallocInst(AllocTy, Expr.Var, Name);
154 assert(AllocTy == Ty);
159 // ExpressionConvertableToType - Return true if it is possible
160 bool ExpressionConvertableToType(Value *V, const Type *Ty,
161 ValueTypeCache &CTMap) {
162 if (V->getType() == Ty) return true; // Expression already correct type!
164 // Expression type must be holdable in a register.
165 if (!Ty->isFirstClassType())
168 ValueTypeCache::iterator CTMI = CTMap.find(V);
169 if (CTMI != CTMap.end()) return CTMI->second == Ty;
173 Instruction *I = dyn_cast<Instruction>(V);
175 // It's not an instruction, check to see if it's a constant... all constants
176 // can be converted to an equivalent value (except pointers, they can't be
177 // const prop'd in general). We just ask the constant propogator to see if
178 // it can convert the value...
180 if (Constant *CPV = dyn_cast<Constant>(V))
181 if (ConstantFoldCastInstruction(CPV, Ty))
182 return true; // Don't worry about deallocating, it's a constant.
184 return false; // Otherwise, we can't convert!
187 switch (I->getOpcode()) {
188 case Instruction::Cast:
189 // We can convert the expr if the cast destination type is losslessly
190 // convertable to the requested type.
191 if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
193 // We also do not allow conversion of a cast that casts from a ptr to array
194 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
196 if (const PointerType *SPT =
197 dyn_cast<PointerType>(I->getOperand(0)->getType()))
198 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
199 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
200 if (AT->getElementType() == DPT->getElementType())
204 case Instruction::Add:
205 case Instruction::Sub:
206 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
207 !ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
210 case Instruction::Shr:
211 if (Ty->isSigned() != V->getType()->isSigned()) return false;
213 case Instruction::Shl:
214 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
218 case Instruction::Load: {
219 LoadInst *LI = cast<LoadInst>(I);
220 if (LI->hasIndices() && !AllIndicesZero(LI)) {
221 // We can't convert a load expression if it has indices... unless they are
226 if (!ExpressionConvertableToType(LI->getPointerOperand(),
227 PointerType::get(Ty), CTMap))
231 case Instruction::PHINode: {
232 PHINode *PN = cast<PHINode>(I);
233 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
234 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
239 case Instruction::Malloc:
240 if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
244 case Instruction::GetElementPtr: {
245 // GetElementPtr's are directly convertable to a pointer type if they have
246 // a number of zeros at the end. Because removing these values does not
247 // change the logical offset of the GEP, it is okay and fair to remove them.
248 // This can change this:
249 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
250 // %t2 = cast %List * * %t1 to %List *
252 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
254 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
255 const PointerType *PTy = dyn_cast<PointerType>(Ty);
256 if (!PTy) return false; // GEP must always return a pointer...
257 const Type *PVTy = PTy->getElementType();
259 // Check to see if there are zero elements that we can remove from the
260 // index array. If there are, check to see if removing them causes us to
261 // get to the right type...
263 std::vector<Value*> Indices = GEP->copyIndices();
264 const Type *BaseType = GEP->getPointerOperand()->getType();
265 const Type *ElTy = 0;
267 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
268 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
270 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
272 break; // Found a match!!
276 if (ElTy) break; // Found a number of zeros we can strip off!
278 // Otherwise, we can convert a GEP from one form to the other iff the
279 // current gep is of the form 'getelementptr sbyte*, unsigned N
280 // and we could convert this to an appropriate GEP for the new type.
282 if (GEP->getNumOperands() == 2 &&
283 GEP->getOperand(1)->getType() == Type::UIntTy &&
284 GEP->getType() == PointerType::get(Type::SByteTy)) {
286 // Do not Check to see if our incoming pointer can be converted
287 // to be a ptr to an array of the right type... because in more cases than
288 // not, it is simply not analyzable because of pointer/array
289 // discrepencies. To fix this, we will insert a cast before the GEP.
292 // Check to see if 'N' is an expression that can be converted to
293 // the appropriate size... if so, allow it.
295 std::vector<Value*> Indices;
296 const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
298 if (!ExpressionConvertableToType(I->getOperand(0),
299 PointerType::get(ElTy), CTMap))
300 return false; // Can't continue, ExConToTy might have polluted set!
305 // Otherwise, it could be that we have something like this:
306 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
307 // and want to convert it into something like this:
308 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
310 if (GEP->getNumOperands() == 2 &&
311 GEP->getOperand(1)->getType() == Type::UIntTy &&
312 TD.getTypeSize(PTy->getElementType()) ==
313 TD.getTypeSize(GEP->getType()->getElementType())) {
314 const PointerType *NewSrcTy = PointerType::get(PVTy);
315 if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
320 return false; // No match, maybe next time.
327 // Expressions are only convertable if all of the users of the expression can
328 // have this value converted. This makes use of the map to avoid infinite
331 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
332 if (!OperandConvertableToType(*It, I, Ty, CTMap))
339 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
340 if (V->getType() == Ty) return V; // Already where we need to be?
342 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
343 if (VMCI != VMC.ExprMap.end()) {
344 assert(VMCI->second->getType() == Ty);
346 if (Instruction *I = dyn_cast<Instruction>(V))
347 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
352 DEBUG(cerr << "CETT: " << (void*)V << " " << V);
354 Instruction *I = dyn_cast<Instruction>(V);
356 if (Constant *CPV = cast<Constant>(V)) {
357 // Constants are converted by constant folding the cast that is required.
358 // We assume here that all casts are implemented for constant prop.
359 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
360 assert(Result && "ConstantFoldCastInstruction Failed!!!");
361 assert(Result->getType() == Ty && "Const prop of cast failed!");
363 // Add the instruction to the expression map
364 VMC.ExprMap[V] = Result;
369 BasicBlock *BB = I->getParent();
370 BasicBlock::InstListType &BIL = BB->getInstList();
371 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
372 Instruction *Res; // Result of conversion
374 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
376 Constant *Dummy = Constant::getNullValue(Ty);
378 switch (I->getOpcode()) {
379 case Instruction::Cast:
380 assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0);
381 Res = new CastInst(I->getOperand(0), Ty, Name);
382 VMC.NewCasts.insert(ValueHandle(VMC, Res));
385 case Instruction::Add:
386 case Instruction::Sub:
387 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
389 VMC.ExprMap[I] = Res; // Add node to expression eagerly
391 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
392 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
395 case Instruction::Shl:
396 case Instruction::Shr:
397 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
398 I->getOperand(1), Name);
399 VMC.ExprMap[I] = Res;
400 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
403 case Instruction::Load: {
404 LoadInst *LI = cast<LoadInst>(I);
405 assert(!LI->hasIndices() || AllIndicesZero(LI));
407 Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
408 VMC.ExprMap[I] = Res;
409 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
410 PointerType::get(Ty), VMC));
411 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
412 assert(Ty == Res->getType());
413 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
417 case Instruction::PHINode: {
418 PHINode *OldPN = cast<PHINode>(I);
419 PHINode *NewPN = new PHINode(Ty, Name);
421 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
422 while (OldPN->getNumOperands()) {
423 BasicBlock *BB = OldPN->getIncomingBlock(0);
424 Value *OldVal = OldPN->getIncomingValue(0);
425 ValueHandle OldValHandle(VMC, OldVal);
426 OldPN->removeIncomingValue(BB);
427 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
428 NewPN->addIncoming(V, BB);
434 case Instruction::Malloc: {
435 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
439 case Instruction::GetElementPtr: {
440 // GetElementPtr's are directly convertable to a pointer type if they have
441 // a number of zeros at the end. Because removing these values does not
442 // change the logical offset of the GEP, it is okay and fair to remove them.
443 // This can change this:
444 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
445 // %t2 = cast %List * * %t1 to %List *
447 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
449 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
451 // Check to see if there are zero elements that we can remove from the
452 // index array. If there are, check to see if removing them causes us to
453 // get to the right type...
455 std::vector<Value*> Indices = GEP->copyIndices();
456 const Type *BaseType = GEP->getPointerOperand()->getType();
457 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
459 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
460 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
462 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
463 if (Indices.size() == 0) {
464 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
466 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
472 if (Res == 0 && GEP->getNumOperands() == 2 &&
473 GEP->getOperand(1)->getType() == Type::UIntTy &&
474 GEP->getType() == PointerType::get(Type::SByteTy)) {
476 // Otherwise, we can convert a GEP from one form to the other iff the
477 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
478 // and we could convert this to an appropriate GEP for the new type.
480 const PointerType *NewSrcTy = PointerType::get(PVTy);
481 BasicBlock::iterator It = I;
483 // Check to see if 'N' is an expression that can be converted to
484 // the appropriate size... if so, allow it.
486 std::vector<Value*> Indices;
487 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
490 assert(ElTy == PVTy && "Internal error, setup wrong!");
491 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
493 VMC.ExprMap[I] = Res;
494 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
499 // Otherwise, it could be that we have something like this:
500 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
501 // and want to convert it into something like this:
502 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
505 const PointerType *NewSrcTy = PointerType::get(PVTy);
506 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
507 GEP->copyIndices(), Name);
508 VMC.ExprMap[I] = Res;
509 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
514 assert(Res && "Didn't find match!");
515 break; // No match, maybe next time.
519 assert(0 && "Expression convertable, but don't know how to convert?");
523 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
527 // Add the instruction to the expression map
528 VMC.ExprMap[I] = Res;
530 // Expressions are only convertable if all of the users of the expression can
531 // have this value converted. This makes use of the map to avoid infinite
534 unsigned NumUses = I->use_size();
535 for (unsigned It = 0; It < NumUses; ) {
536 unsigned OldSize = NumUses;
537 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
538 NumUses = I->use_size();
539 if (NumUses == OldSize) ++It;
542 DEBUG(cerr << "ExpIn: " << (void*)I << " " << I
543 << "ExpOut: " << (void*)Res << " " << Res);
550 // ValueConvertableToType - Return true if it is possible
551 bool ValueConvertableToType(Value *V, const Type *Ty,
552 ValueTypeCache &ConvertedTypes) {
553 ValueTypeCache::iterator I = ConvertedTypes.find(V);
554 if (I != ConvertedTypes.end()) return I->second == Ty;
555 ConvertedTypes[V] = Ty;
557 // It is safe to convert the specified value to the specified type IFF all of
558 // the uses of the value can be converted to accept the new typed value.
560 if (V->getType() != Ty) {
561 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
562 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
573 // OperandConvertableToType - Return true if it is possible to convert operand
574 // V of User (instruction) U to the specified type. This is true iff it is
575 // possible to change the specified instruction to accept this. CTMap is a map
576 // of converted types, so that circular definitions will see the future type of
577 // the expression, not the static current type.
579 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
580 ValueTypeCache &CTMap) {
581 // if (V->getType() == Ty) return true; // Operand already the right type?
583 // Expression type must be holdable in a register.
584 if (!Ty->isFirstClassType())
587 Instruction *I = dyn_cast<Instruction>(U);
588 if (I == 0) return false; // We can't convert!
590 switch (I->getOpcode()) {
591 case Instruction::Cast:
592 assert(I->getOperand(0) == V);
593 // We can convert the expr if the cast destination type is losslessly
594 // convertable to the requested type.
595 // Also, do not change a cast that is a noop cast. For all intents and
596 // purposes it should be eliminated.
597 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
598 I->getType() == I->getOperand(0)->getType())
601 // Do not allow a 'cast ushort %V to uint' to have it's first operand be
602 // converted to a 'short' type. Doing so changes the way sign promotion
603 // happens, and breaks things. Only allow the cast to take place if the
604 // signedness doesn't change... or if the current cast is not a lossy
607 if (!I->getType()->isLosslesslyConvertableTo(I->getOperand(0)->getType()) &&
608 I->getOperand(0)->getType()->isSigned() != Ty->isSigned())
611 // We also do not allow conversion of a cast that casts from a ptr to array
612 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
614 if (const PointerType *SPT =
615 dyn_cast<PointerType>(I->getOperand(0)->getType()))
616 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
617 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
618 if (AT->getElementType() == DPT->getElementType())
622 case Instruction::Add:
623 if (isa<PointerType>(Ty)) {
624 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
625 std::vector<Value*> Indices;
626 if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
627 const Type *RetTy = PointerType::get(ETy);
629 // Only successful if we can convert this type to the required type
630 if (ValueConvertableToType(I, RetTy, CTMap)) {
634 // We have to return failure here because ValueConvertableToType could
635 // have polluted our map
640 case Instruction::Sub: {
641 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
642 return ValueConvertableToType(I, Ty, CTMap) &&
643 ExpressionConvertableToType(OtherOp, Ty, CTMap);
645 case Instruction::SetEQ:
646 case Instruction::SetNE: {
647 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
648 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
650 case Instruction::Shr:
651 if (Ty->isSigned() != V->getType()->isSigned()) return false;
653 case Instruction::Shl:
654 assert(I->getOperand(0) == V);
655 return ValueConvertableToType(I, Ty, CTMap);
657 case Instruction::Free:
658 assert(I->getOperand(0) == V);
659 return isa<PointerType>(Ty); // Free can free any pointer type!
661 case Instruction::Load:
662 // Cannot convert the types of any subscripts...
663 if (I->getOperand(0) != V) return false;
665 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
666 LoadInst *LI = cast<LoadInst>(I);
668 if (LI->hasIndices() && !AllIndicesZero(LI))
671 const Type *LoadedTy = PT->getElementType();
673 // They could be loading the first element of a composite type...
674 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
675 unsigned Offset = 0; // No offset, get first leaf.
676 std::vector<Value*> Indices; // Discarded...
677 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
678 assert(Offset == 0 && "Offset changed from zero???");
681 if (!LoadedTy->isFirstClassType())
684 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
687 return ValueConvertableToType(LI, LoadedTy, CTMap);
691 case Instruction::Store: {
692 StoreInst *SI = cast<StoreInst>(I);
693 if (SI->hasIndices()) return false;
695 if (V == I->getOperand(0)) {
696 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
697 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
698 // If so, check to see if it's Ty*, or, more importantly, if it is a
699 // pointer to a structure where the first element is a Ty... this code
700 // is neccesary because we might be trying to change the source and
701 // destination type of the store (they might be related) and the dest
702 // pointer type might be a pointer to structure. Below we allow pointer
703 // to structures where the 0th element is compatible with the value,
704 // now we have to support the symmetrical part of this.
706 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
708 // Already a pointer to what we want? Trivially accept...
709 if (ElTy == Ty) return true;
711 // Tricky case now, if the destination is a pointer to structure,
712 // obviously the source is not allowed to be a structure (cannot copy
713 // a whole structure at a time), so the level raiser must be trying to
714 // store into the first field. Check for this and allow it now:
716 if (const StructType *SElTy = dyn_cast<StructType>(ElTy)) {
718 std::vector<Value*> Indices;
719 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
720 assert(Offset == 0 && "Offset changed!");
721 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
722 return false; // Can only happen for {}*
724 if (ElTy == Ty) // Looks like the 0th element of structure is
725 return true; // compatible! Accept now!
727 // Otherwise we know that we can't work, so just stop trying now.
732 // Can convert the store if we can convert the pointer operand to match
733 // the new value type...
734 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
736 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
737 const Type *ElTy = PT->getElementType();
738 assert(V == I->getOperand(1));
740 if (isa<StructType>(ElTy)) {
741 // We can change the destination pointer if we can store our first
742 // argument into the first element of the structure...
745 std::vector<Value*> Indices;
746 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
747 assert(Offset == 0 && "Offset changed!");
748 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
749 return false; // Can only happen for {}*
752 // Must move the same amount of data...
753 if (!ElTy->isSized() ||
754 TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
757 // Can convert store if the incoming value is convertable...
758 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
763 case Instruction::GetElementPtr:
764 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
766 // If we have a two operand form of getelementptr, this is really little
767 // more than a simple addition. As with addition, check to see if the
768 // getelementptr instruction can be changed to index into the new type.
770 if (I->getNumOperands() == 2) {
771 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
772 unsigned DataSize = TD.getTypeSize(OldElTy);
773 Value *Index = I->getOperand(1);
774 Instruction *TempScale = 0;
776 // If the old data element is not unit sized, we have to create a scale
777 // instruction so that ConvertableToGEP will know the REAL amount we are
778 // indexing by. Note that this is never inserted into the instruction
779 // stream, so we have to delete it when we're done.
782 TempScale = BinaryOperator::create(Instruction::Mul, Index,
783 ConstantUInt::get(Type::UIntTy,
788 // Check to see if the second argument is an expression that can
789 // be converted to the appropriate size... if so, allow it.
791 std::vector<Value*> Indices;
792 const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
793 delete TempScale; // Free our temporary multiply if we made it
795 if (ElTy == 0) return false; // Cannot make conversion...
796 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
800 case Instruction::PHINode: {
801 PHINode *PN = cast<PHINode>(I);
802 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
803 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
805 return ValueConvertableToType(PN, Ty, CTMap);
808 case Instruction::Call: {
809 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
810 assert (OI != I->op_end() && "Not using value!");
811 unsigned OpNum = OI - I->op_begin();
813 // Are we trying to change the function pointer value to a new type?
815 const PointerType *PTy = dyn_cast<PointerType>(Ty);
816 if (PTy == 0) return false; // Can't convert to a non-pointer type...
817 const FunctionType *MTy = dyn_cast<FunctionType>(PTy->getElementType());
818 if (MTy == 0) return false; // Can't convert to a non ptr to function...
820 // Perform sanity checks to make sure that new function type has the
821 // correct number of arguments...
823 unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr
825 // Cannot convert to a type that requires more fixed arguments than
826 // the call provides...
828 if (NumArgs < MTy->getParamTypes().size()) return false;
830 // Unless this is a vararg function type, we cannot provide more arguments
831 // than are desired...
833 if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
836 // Okay, at this point, we know that the call and the function type match
837 // number of arguments. Now we see if we can convert the arguments
838 // themselves. Note that we do not require operands to be convertable,
839 // we can insert casts if they are convertible but not compatible. The
840 // reason for this is that we prefer to have resolved functions but casted
841 // arguments if possible.
843 const FunctionType::ParamTypes &PTs = MTy->getParamTypes();
844 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
845 if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
846 return false; // Operands must have compatible types!
848 // Okay, at this point, we know that all of the arguments can be
849 // converted. We succeed if we can change the return type if
852 return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
855 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
856 const FunctionType *MTy = cast<FunctionType>(MPtr->getElementType());
857 if (!MTy->isVarArg()) return false;
859 if ((OpNum-1) < MTy->getParamTypes().size())
860 return false; // It's not in the varargs section...
862 // If we get this far, we know the value is in the varargs section of the
863 // function! We can convert if we don't reinterpret the value...
865 return Ty->isLosslesslyConvertableTo(V->getType());
872 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
873 ValueHandle VH(VMC, V);
875 unsigned NumUses = V->use_size();
876 for (unsigned It = 0; It < NumUses; ) {
877 unsigned OldSize = NumUses;
878 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
879 NumUses = V->use_size();
880 if (NumUses == OldSize) ++It;
886 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
887 ValueMapCache &VMC) {
888 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
890 if (VMC.OperandsMapped.count(U)) return;
891 VMC.OperandsMapped.insert(U);
893 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
894 if (VMCI != VMC.ExprMap.end())
898 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
900 BasicBlock *BB = I->getParent();
901 assert(BB != 0 && "Instruction not embedded in basic block!");
902 BasicBlock::InstListType &BIL = BB->getInstList();
903 std::string Name = I->getName();
905 Instruction *Res; // Result of conversion
907 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
909 // Prevent I from being removed...
910 ValueHandle IHandle(VMC, I);
912 const Type *NewTy = NewVal->getType();
913 Constant *Dummy = (NewTy != Type::VoidTy) ?
914 Constant::getNullValue(NewTy) : 0;
916 switch (I->getOpcode()) {
917 case Instruction::Cast:
918 if (VMC.NewCasts.count(ValueHandle(VMC, I))) {
919 // This cast has already had it's value converted, causing a new cast to
920 // be created. We don't want to create YET ANOTHER cast instruction
921 // representing the original one, so just modify the operand of this cast
922 // instruction, which we know is newly created.
923 I->setOperand(0, NewVal);
924 I->setName(Name); // give I its name back
928 Res = new CastInst(NewVal, I->getType(), Name);
932 case Instruction::Add:
933 if (isa<PointerType>(NewTy)) {
934 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
935 std::vector<Value*> Indices;
936 BasicBlock::iterator It = I;
938 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
939 // If successful, convert the add to a GEP
940 //const Type *RetTy = PointerType::get(ETy);
941 // First operand is actually the given pointer...
942 Res = new GetElementPtrInst(NewVal, Indices, Name);
943 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
944 "ConvertableToGEP broken!");
950 case Instruction::Sub:
951 case Instruction::SetEQ:
952 case Instruction::SetNE: {
953 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
955 VMC.ExprMap[I] = Res; // Add node to expression eagerly
957 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
958 Value *OtherOp = I->getOperand(OtherIdx);
959 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
961 Res->setOperand(OtherIdx, NewOther);
962 Res->setOperand(!OtherIdx, NewVal);
965 case Instruction::Shl:
966 case Instruction::Shr:
967 assert(I->getOperand(0) == OldVal);
968 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
969 I->getOperand(1), Name);
972 case Instruction::Free: // Free can free any pointer type!
973 assert(I->getOperand(0) == OldVal);
974 Res = new FreeInst(NewVal);
978 case Instruction::Load: {
979 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
980 const Type *LoadedTy =
981 cast<PointerType>(NewVal->getType())->getElementType();
983 std::vector<Value*> Indices;
984 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
986 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
987 unsigned Offset = 0; // No offset, get first leaf.
988 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
990 assert(LoadedTy->isFirstClassType());
992 Res = new LoadInst(NewVal, Indices, Name);
993 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
997 case Instruction::Store: {
998 if (I->getOperand(0) == OldVal) { // Replace the source value
999 const PointerType *NewPT = PointerType::get(NewTy);
1000 Res = new StoreInst(NewVal, Constant::getNullValue(NewPT));
1001 VMC.ExprMap[I] = Res;
1002 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC));
1003 } else { // Replace the source pointer
1004 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1005 std::vector<Value*> Indices;
1007 if (isa<StructType>(ValTy)) {
1008 unsigned Offset = 0;
1009 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
1010 ValTy = getStructOffsetType(ValTy, Offset, Indices, false);
1011 assert(Offset == 0 && ValTy);
1014 Res = new StoreInst(Constant::getNullValue(ValTy), NewVal, Indices);
1015 VMC.ExprMap[I] = Res;
1016 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
1022 case Instruction::GetElementPtr: {
1023 // Convert a one index getelementptr into just about anything that is
1026 BasicBlock::iterator It = I;
1027 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
1028 unsigned DataSize = TD.getTypeSize(OldElTy);
1029 Value *Index = I->getOperand(1);
1031 if (DataSize != 1) {
1032 // Insert a multiply of the old element type is not a unit size...
1033 Index = BinaryOperator::create(Instruction::Mul, Index,
1034 ConstantUInt::get(Type::UIntTy, DataSize));
1035 It = ++BIL.insert(It, cast<Instruction>(Index));
1038 // Perform the conversion now...
1040 std::vector<Value*> Indices;
1041 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
1042 assert(ElTy != 0 && "GEP Conversion Failure!");
1043 Res = new GetElementPtrInst(NewVal, Indices, Name);
1044 assert(Res->getType() == PointerType::get(ElTy) &&
1045 "ConvertableToGet failed!");
1048 if (I->getType() == PointerType::get(Type::SByteTy)) {
1049 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1050 // anything that is a pointer type...
1052 BasicBlock::iterator It = I;
1054 // Check to see if the second argument is an expression that can
1055 // be converted to the appropriate size... if so, allow it.
1057 std::vector<Value*> Indices;
1058 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
1060 assert(ElTy != 0 && "GEP Conversion Failure!");
1062 Res = new GetElementPtrInst(NewVal, Indices, Name);
1064 // Convert a getelementptr ulong * %reg123, uint %N
1065 // to getelementptr long * %reg123, uint %N
1066 // ... where the type must simply stay the same size...
1068 Res = new GetElementPtrInst(NewVal,
1069 cast<GetElementPtrInst>(I)->copyIndices(),
1075 case Instruction::PHINode: {
1076 PHINode *OldPN = cast<PHINode>(I);
1077 PHINode *NewPN = new PHINode(NewTy, Name);
1078 VMC.ExprMap[I] = NewPN;
1080 while (OldPN->getNumOperands()) {
1081 BasicBlock *BB = OldPN->getIncomingBlock(0);
1082 Value *OldVal = OldPN->getIncomingValue(0);
1083 OldPN->removeIncomingValue(BB);
1084 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
1085 NewPN->addIncoming(V, BB);
1091 case Instruction::Call: {
1092 Value *Meth = I->getOperand(0);
1093 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1095 if (Meth == OldVal) { // Changing the function pointer?
1096 const PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1097 const FunctionType *NewTy = cast<FunctionType>(NewPTy->getElementType());
1098 const FunctionType::ParamTypes &PTs = NewTy->getParamTypes();
1100 // Get an iterator to the call instruction so that we can insert casts for
1101 // operands if needbe. Note that we do not require operands to be
1102 // convertable, we can insert casts if they are convertible but not
1103 // compatible. The reason for this is that we prefer to have resolved
1104 // functions but casted arguments if possible.
1106 BasicBlock::iterator It = I;
1108 // Convert over all of the call operands to their new types... but only
1109 // convert over the part that is not in the vararg section of the call.
1111 for (unsigned i = 0; i < PTs.size(); ++i)
1112 if (Params[i]->getType() != PTs[i]) {
1113 // Create a cast to convert it to the right type, we know that this
1114 // is a lossless cast...
1116 Params[i] = new CastInst(Params[i], PTs[i], "call.resolve.cast");
1117 It = ++BIL.insert(It, cast<Instruction>(Params[i]));
1119 Meth = NewVal; // Update call destination to new value
1121 } else { // Changing an argument, must be in vararg area
1122 std::vector<Value*>::iterator OI =
1123 find(Params.begin(), Params.end(), OldVal);
1124 assert (OI != Params.end() && "Not using value!");
1129 Res = new CallInst(Meth, Params, Name);
1133 assert(0 && "Expression convertable, but don't know how to convert?");
1137 // If the instruction was newly created, insert it into the instruction
1140 BasicBlock::iterator It = I;
1141 assert(It != BIL.end() && "Instruction not in own basic block??");
1142 BIL.insert(It, Res); // Keep It pointing to old instruction
1144 DEBUG(cerr << "COT CREATED: " << (void*)Res << " " << Res
1145 << "In: " << (void*)I << " " << I << "Out: " << (void*)Res
1148 // Add the instruction to the expression map
1149 VMC.ExprMap[I] = Res;
1151 if (I->getType() != Res->getType())
1152 ConvertValueToNewType(I, Res, VMC);
1154 for (unsigned It = 0; It < I->use_size(); ) {
1155 User *Use = *(I->use_begin()+It);
1156 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1159 Use->replaceUsesOfWith(I, Res);
1162 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1164 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1169 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1170 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1171 //DEBUG(cerr << "VH AQUIRING: " << (void*)V << " " << V);
1172 Operands.push_back(Use(V, this));
1175 ValueHandle::ValueHandle(const ValueHandle &VH)
1176 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VH.Cache) {
1177 //DEBUG(cerr << "VH AQUIRING: " << (void*)V << " " << V);
1178 Operands.push_back(Use((Value*)VH.getOperand(0), this));
1181 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1182 if (!I || !I->use_empty()) return;
1184 assert(I->getParent() && "Inst not in basic block!");
1186 //DEBUG(cerr << "VH DELETING: " << (void*)I << " " << I);
1188 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1190 if (Instruction *U = dyn_cast<Instruction>(OI->get())) {
1192 RecursiveDelete(Cache, U);
1195 I->getParent()->getInstList().remove(I);
1197 Cache.OperandsMapped.erase(I);
1198 Cache.ExprMap.erase(I);
1202 ValueHandle::~ValueHandle() {
1203 if (Operands[0]->use_size() == 1) {
1204 Value *V = Operands[0];
1205 Operands[0] = 0; // Drop use!
1207 // Now we just need to remove the old instruction so we don't get infinite
1208 // loops. Note that we cannot use DCE because DCE won't remove a store
1209 // instruction, for example.
1211 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1213 //DEBUG(cerr << "VH RELEASING: " << (void*)Operands[0].get() << " "
1214 // << Operands[0]->use_size() << " " << Operands[0]);