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"
20 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
21 ValueTypeCache &ConvertedTypes);
23 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
26 // Peephole Malloc instructions: we take a look at the use chain of the
27 // malloc instruction, and try to find out if the following conditions hold:
28 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
29 // 2. The only users of the malloc are cast & add instructions
30 // 3. Of the cast instructions, there is only one destination pointer type
31 // [RTy] where the size of the pointed to object is equal to the number
32 // of bytes allocated.
34 // If these conditions hold, we convert the malloc to allocate an [RTy]
35 // element. TODO: This comment is out of date WRT arrays
37 static bool MallocConvertableToType(MallocInst *MI, const Type *Ty,
38 ValueTypeCache &CTMap) {
39 if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
41 // Deal with the type to allocate, not the pointer type...
42 Ty = cast<PointerType>(Ty)->getElementType();
43 if (!Ty->isSized()) return false; // Can only alloc something with a size
45 // Analyze the number of bytes allocated...
46 ExprType Expr = ClassifyExpression(MI->getArraySize());
48 // Get information about the base datatype being allocated, before & after
49 int ReqTypeSize = TD.getTypeSize(Ty);
50 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
52 // Must have a scale or offset to analyze it...
53 if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
55 // Get the offset and scale of the allocation...
56 int OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
57 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
59 // The old type might not be of unit size, take old size into consideration
61 int Offset = OffsetVal * OldTypeSize;
62 int Scale = ScaleVal * OldTypeSize;
64 // In order to be successful, both the scale and the offset must be a multiple
65 // of the requested data type's size.
67 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
68 Scale/ReqTypeSize*ReqTypeSize != Scale)
69 return false; // Nope.
74 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
75 const std::string &Name,
77 BasicBlock *BB = MI->getParent();
78 BasicBlock::iterator It = BB->end();
80 // Analyze the number of bytes allocated...
81 ExprType Expr = ClassifyExpression(MI->getArraySize());
83 const PointerType *AllocTy = cast<PointerType>(Ty);
84 const Type *ElType = AllocTy->getElementType();
86 unsigned DataSize = TD.getTypeSize(ElType);
87 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
89 // Get the offset and scale coefficients that we are allocating...
90 int OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
91 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
93 // The old type might not be of unit size, take old size into consideration
95 unsigned Offset = (unsigned)OffsetVal * OldTypeSize / DataSize;
96 unsigned Scale = (unsigned)ScaleVal * OldTypeSize / DataSize;
98 // Locate the malloc instruction, because we may be inserting instructions
101 // If we have a scale, apply it first...
103 // Expr.Var is not neccesarily unsigned right now, insert a cast now.
104 if (Expr.Var->getType() != Type::UIntTy)
105 Expr.Var = new CastInst(Expr.Var, Type::UIntTy,
106 Expr.Var->getName()+"-uint", It);
109 Expr.Var = BinaryOperator::create(Instruction::Mul, Expr.Var,
110 ConstantUInt::get(Type::UIntTy, Scale),
111 Expr.Var->getName()+"-scl", It);
114 // If we are not scaling anything, just make the offset be the "var"...
115 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
116 Offset = 0; Scale = 1;
119 // If we have an offset now, add it in...
121 assert(Expr.Var && "Var must be nonnull by now!");
122 Expr.Var = BinaryOperator::create(Instruction::Add, Expr.Var,
123 ConstantUInt::get(Type::UIntTy, Offset),
124 Expr.Var->getName()+"-off", It);
127 Instruction *NewI = new MallocInst(AllocTy, Expr.Var, Name);
129 assert(AllocTy == Ty);
134 // ExpressionConvertableToType - Return true if it is possible
135 bool ExpressionConvertableToType(Value *V, const Type *Ty,
136 ValueTypeCache &CTMap) {
137 // Expression type must be holdable in a register.
138 if (!Ty->isFirstClassType())
141 ValueTypeCache::iterator CTMI = CTMap.find(V);
142 if (CTMI != CTMap.end()) return CTMI->second == Ty;
145 if (V->getType() == Ty) return true; // Expression already correct type!
147 Instruction *I = dyn_cast<Instruction>(V);
149 // It's not an instruction, check to see if it's a constant... all constants
150 // can be converted to an equivalent value (except pointers, they can't be
151 // const prop'd in general). We just ask the constant propogator to see if
152 // it can convert the value...
154 if (Constant *CPV = dyn_cast<Constant>(V))
155 if (ConstantFoldCastInstruction(CPV, Ty))
156 return true; // Don't worry about deallocating, it's a constant.
158 return false; // Otherwise, we can't convert!
161 switch (I->getOpcode()) {
162 case Instruction::Cast:
163 // We can convert the expr if the cast destination type is losslessly
164 // convertable to the requested type.
165 if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
167 // We also do not allow conversion of a cast that casts from a ptr to array
168 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
170 if (const PointerType *SPT =
171 dyn_cast<PointerType>(I->getOperand(0)->getType()))
172 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
173 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
174 if (AT->getElementType() == DPT->getElementType())
178 case Instruction::Add:
179 case Instruction::Sub:
180 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
181 !ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
184 case Instruction::Shr:
185 if (!Ty->isInteger()) return false;
186 if (Ty->isSigned() != V->getType()->isSigned()) return false;
188 case Instruction::Shl:
189 if (!Ty->isInteger()) return false;
190 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
194 case Instruction::Load: {
195 LoadInst *LI = cast<LoadInst>(I);
196 if (!ExpressionConvertableToType(LI->getPointerOperand(),
197 PointerType::get(Ty), CTMap))
201 case Instruction::PHINode: {
202 PHINode *PN = cast<PHINode>(I);
203 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
204 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
209 case Instruction::Malloc:
210 if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
214 case Instruction::GetElementPtr: {
215 // GetElementPtr's are directly convertable to a pointer type if they have
216 // a number of zeros at the end. Because removing these values does not
217 // change the logical offset of the GEP, it is okay and fair to remove them.
218 // This can change this:
219 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
220 // %t2 = cast %List * * %t1 to %List *
222 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
224 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
225 const PointerType *PTy = dyn_cast<PointerType>(Ty);
226 if (!PTy) return false; // GEP must always return a pointer...
227 const Type *PVTy = PTy->getElementType();
229 // Check to see if there are zero elements that we can remove from the
230 // index array. If there are, check to see if removing them causes us to
231 // get to the right type...
233 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
234 const Type *BaseType = GEP->getPointerOperand()->getType();
235 const Type *ElTy = 0;
237 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
238 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
240 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
242 break; // Found a match!!
246 if (ElTy) break; // Found a number of zeros we can strip off!
248 // Otherwise, we can convert a GEP from one form to the other iff the
249 // current gep is of the form 'getelementptr sbyte*, unsigned N
250 // and we could convert this to an appropriate GEP for the new type.
252 if (GEP->getNumOperands() == 2 &&
253 GEP->getOperand(1)->getType() == Type::UIntTy &&
254 GEP->getType() == PointerType::get(Type::SByteTy)) {
256 // Do not Check to see if our incoming pointer can be converted
257 // to be a ptr to an array of the right type... because in more cases than
258 // not, it is simply not analyzable because of pointer/array
259 // discrepencies. To fix this, we will insert a cast before the GEP.
262 // Check to see if 'N' is an expression that can be converted to
263 // the appropriate size... if so, allow it.
265 std::vector<Value*> Indices;
266 const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
268 if (!ExpressionConvertableToType(I->getOperand(0),
269 PointerType::get(ElTy), CTMap))
270 return false; // Can't continue, ExConToTy might have polluted set!
275 // Otherwise, it could be that we have something like this:
276 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
277 // and want to convert it into something like this:
278 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
280 if (GEP->getNumOperands() == 2 &&
281 GEP->getOperand(1)->getType() == Type::UIntTy &&
282 TD.getTypeSize(PTy->getElementType()) ==
283 TD.getTypeSize(GEP->getType()->getElementType())) {
284 const PointerType *NewSrcTy = PointerType::get(PVTy);
285 if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
290 return false; // No match, maybe next time.
297 // Expressions are only convertable if all of the users of the expression can
298 // have this value converted. This makes use of the map to avoid infinite
301 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
302 if (!OperandConvertableToType(*It, I, Ty, CTMap))
309 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
310 if (V->getType() == Ty) return V; // Already where we need to be?
312 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
313 if (VMCI != VMC.ExprMap.end()) {
314 const Value *GV = VMCI->second;
315 const Type *GTy = VMCI->second->getType();
316 assert(VMCI->second->getType() == Ty);
318 if (Instruction *I = dyn_cast<Instruction>(V))
319 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
324 DEBUG(cerr << "CETT: " << (void*)V << " " << V);
326 Instruction *I = dyn_cast<Instruction>(V);
328 if (Constant *CPV = cast<Constant>(V)) {
329 // Constants are converted by constant folding the cast that is required.
330 // We assume here that all casts are implemented for constant prop.
331 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
332 assert(Result && "ConstantFoldCastInstruction Failed!!!");
333 assert(Result->getType() == Ty && "Const prop of cast failed!");
335 // Add the instruction to the expression map
336 VMC.ExprMap[V] = Result;
341 BasicBlock *BB = I->getParent();
342 BasicBlock::InstListType &BIL = BB->getInstList();
343 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
344 Instruction *Res; // Result of conversion
346 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
348 Constant *Dummy = Constant::getNullValue(Ty);
350 switch (I->getOpcode()) {
351 case Instruction::Cast:
352 assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0);
353 Res = new CastInst(I->getOperand(0), Ty, Name);
354 VMC.NewCasts.insert(ValueHandle(VMC, Res));
357 case Instruction::Add:
358 case Instruction::Sub:
359 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
361 VMC.ExprMap[I] = Res; // Add node to expression eagerly
363 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
364 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
367 case Instruction::Shl:
368 case Instruction::Shr:
369 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
370 I->getOperand(1), Name);
371 VMC.ExprMap[I] = Res;
372 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
375 case Instruction::Load: {
376 LoadInst *LI = cast<LoadInst>(I);
378 Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
379 VMC.ExprMap[I] = Res;
380 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
381 PointerType::get(Ty), VMC));
382 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
383 assert(Ty == Res->getType());
384 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
388 case Instruction::PHINode: {
389 PHINode *OldPN = cast<PHINode>(I);
390 PHINode *NewPN = new PHINode(Ty, Name);
392 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
393 while (OldPN->getNumOperands()) {
394 BasicBlock *BB = OldPN->getIncomingBlock(0);
395 Value *OldVal = OldPN->getIncomingValue(0);
396 ValueHandle OldValHandle(VMC, OldVal);
397 OldPN->removeIncomingValue(BB);
398 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
399 NewPN->addIncoming(V, BB);
405 case Instruction::Malloc: {
406 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
410 case Instruction::GetElementPtr: {
411 // GetElementPtr's are directly convertable to a pointer type if they have
412 // a number of zeros at the end. Because removing these values does not
413 // change the logical offset of the GEP, it is okay and fair to remove them.
414 // This can change this:
415 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
416 // %t2 = cast %List * * %t1 to %List *
418 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
420 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
422 // Check to see if there are zero elements that we can remove from the
423 // index array. If there are, check to see if removing them causes us to
424 // get to the right type...
426 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
427 const Type *BaseType = GEP->getPointerOperand()->getType();
428 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
430 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
431 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
433 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
434 if (Indices.size() == 0) {
435 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
437 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
443 if (Res == 0 && GEP->getNumOperands() == 2 &&
444 GEP->getOperand(1)->getType() == Type::UIntTy &&
445 GEP->getType() == PointerType::get(Type::SByteTy)) {
447 // Otherwise, we can convert a GEP from one form to the other iff the
448 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
449 // and we could convert this to an appropriate GEP for the new type.
451 const PointerType *NewSrcTy = PointerType::get(PVTy);
452 BasicBlock::iterator It = I;
454 // Check to see if 'N' is an expression that can be converted to
455 // the appropriate size... if so, allow it.
457 std::vector<Value*> Indices;
458 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
461 assert(ElTy == PVTy && "Internal error, setup wrong!");
462 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
464 VMC.ExprMap[I] = Res;
465 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
470 // Otherwise, it could be that we have something like this:
471 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
472 // and want to convert it into something like this:
473 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
476 const PointerType *NewSrcTy = PointerType::get(PVTy);
477 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
478 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
480 VMC.ExprMap[I] = Res;
481 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
486 assert(Res && "Didn't find match!");
487 break; // No match, maybe next time.
491 assert(0 && "Expression convertable, but don't know how to convert?");
495 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
499 // Add the instruction to the expression map
500 VMC.ExprMap[I] = Res;
502 // Expressions are only convertable if all of the users of the expression can
503 // have this value converted. This makes use of the map to avoid infinite
506 unsigned NumUses = I->use_size();
507 for (unsigned It = 0; It < NumUses; ) {
508 unsigned OldSize = NumUses;
509 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
510 NumUses = I->use_size();
511 if (NumUses == OldSize) ++It;
514 DEBUG(cerr << "ExpIn: " << (void*)I << " " << I
515 << "ExpOut: " << (void*)Res << " " << Res);
522 // ValueConvertableToType - Return true if it is possible
523 bool ValueConvertableToType(Value *V, const Type *Ty,
524 ValueTypeCache &ConvertedTypes) {
525 ValueTypeCache::iterator I = ConvertedTypes.find(V);
526 if (I != ConvertedTypes.end()) return I->second == Ty;
527 ConvertedTypes[V] = Ty;
529 // It is safe to convert the specified value to the specified type IFF all of
530 // the uses of the value can be converted to accept the new typed value.
532 if (V->getType() != Ty) {
533 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
534 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
545 // OperandConvertableToType - Return true if it is possible to convert operand
546 // V of User (instruction) U to the specified type. This is true iff it is
547 // possible to change the specified instruction to accept this. CTMap is a map
548 // of converted types, so that circular definitions will see the future type of
549 // the expression, not the static current type.
551 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
552 ValueTypeCache &CTMap) {
553 // if (V->getType() == Ty) return true; // Operand already the right type?
555 // Expression type must be holdable in a register.
556 if (!Ty->isFirstClassType())
559 Instruction *I = dyn_cast<Instruction>(U);
560 if (I == 0) return false; // We can't convert!
562 switch (I->getOpcode()) {
563 case Instruction::Cast:
564 assert(I->getOperand(0) == V);
565 // We can convert the expr if the cast destination type is losslessly
566 // convertable to the requested type.
567 // Also, do not change a cast that is a noop cast. For all intents and
568 // purposes it should be eliminated.
569 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
570 I->getType() == I->getOperand(0)->getType())
573 // Do not allow a 'cast ushort %V to uint' to have it's first operand be
574 // converted to a 'short' type. Doing so changes the way sign promotion
575 // happens, and breaks things. Only allow the cast to take place if the
576 // signedness doesn't change... or if the current cast is not a lossy
579 if (!I->getType()->isLosslesslyConvertableTo(I->getOperand(0)->getType()) &&
580 I->getOperand(0)->getType()->isSigned() != Ty->isSigned())
583 // We also do not allow conversion of a cast that casts from a ptr to array
584 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
586 if (const PointerType *SPT =
587 dyn_cast<PointerType>(I->getOperand(0)->getType()))
588 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
589 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
590 if (AT->getElementType() == DPT->getElementType())
594 case Instruction::Add:
595 if (isa<PointerType>(Ty)) {
596 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
597 std::vector<Value*> Indices;
598 if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
599 const Type *RetTy = PointerType::get(ETy);
601 // Only successful if we can convert this type to the required type
602 if (ValueConvertableToType(I, RetTy, CTMap)) {
606 // We have to return failure here because ValueConvertableToType could
607 // have polluted our map
612 case Instruction::Sub: {
613 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
614 return ValueConvertableToType(I, Ty, CTMap) &&
615 ExpressionConvertableToType(OtherOp, Ty, CTMap);
617 case Instruction::SetEQ:
618 case Instruction::SetNE: {
619 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
620 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
622 case Instruction::Shr:
623 if (Ty->isSigned() != V->getType()->isSigned()) return false;
625 case Instruction::Shl:
626 assert(I->getOperand(0) == V);
627 if (!Ty->isInteger()) return false;
628 return ValueConvertableToType(I, Ty, CTMap);
630 case Instruction::Free:
631 assert(I->getOperand(0) == V);
632 return isa<PointerType>(Ty); // Free can free any pointer type!
634 case Instruction::Load:
635 // Cannot convert the types of any subscripts...
636 if (I->getOperand(0) != V) return false;
638 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
639 LoadInst *LI = cast<LoadInst>(I);
641 const Type *LoadedTy = PT->getElementType();
643 // They could be loading the first element of a composite type...
644 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
645 unsigned Offset = 0; // No offset, get first leaf.
646 std::vector<Value*> Indices; // Discarded...
647 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
648 assert(Offset == 0 && "Offset changed from zero???");
651 if (!LoadedTy->isFirstClassType())
654 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
657 return ValueConvertableToType(LI, LoadedTy, CTMap);
661 case Instruction::Store: {
662 StoreInst *SI = cast<StoreInst>(I);
664 if (V == I->getOperand(0)) {
665 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
666 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
667 // If so, check to see if it's Ty*, or, more importantly, if it is a
668 // pointer to a structure where the first element is a Ty... this code
669 // is neccesary because we might be trying to change the source and
670 // destination type of the store (they might be related) and the dest
671 // pointer type might be a pointer to structure. Below we allow pointer
672 // to structures where the 0th element is compatible with the value,
673 // now we have to support the symmetrical part of this.
675 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
677 // Already a pointer to what we want? Trivially accept...
678 if (ElTy == Ty) return true;
680 // Tricky case now, if the destination is a pointer to structure,
681 // obviously the source is not allowed to be a structure (cannot copy
682 // a whole structure at a time), so the level raiser must be trying to
683 // store into the first field. Check for this and allow it now:
685 if (const StructType *SElTy = dyn_cast<StructType>(ElTy)) {
687 std::vector<Value*> Indices;
688 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
689 assert(Offset == 0 && "Offset changed!");
690 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
691 return false; // Can only happen for {}*
693 if (ElTy == Ty) // Looks like the 0th element of structure is
694 return true; // compatible! Accept now!
696 // Otherwise we know that we can't work, so just stop trying now.
701 // Can convert the store if we can convert the pointer operand to match
702 // the new value type...
703 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
705 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
706 const Type *ElTy = PT->getElementType();
707 assert(V == I->getOperand(1));
709 if (isa<StructType>(ElTy)) {
710 // We can change the destination pointer if we can store our first
711 // argument into the first element of the structure...
714 std::vector<Value*> Indices;
715 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
716 assert(Offset == 0 && "Offset changed!");
717 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
718 return false; // Can only happen for {}*
721 // Must move the same amount of data...
722 if (!ElTy->isSized() ||
723 TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
726 // Can convert store if the incoming value is convertable...
727 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
732 case Instruction::GetElementPtr:
733 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
735 // If we have a two operand form of getelementptr, this is really little
736 // more than a simple addition. As with addition, check to see if the
737 // getelementptr instruction can be changed to index into the new type.
739 if (I->getNumOperands() == 2) {
740 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
741 unsigned DataSize = TD.getTypeSize(OldElTy);
742 Value *Index = I->getOperand(1);
743 Instruction *TempScale = 0;
745 // If the old data element is not unit sized, we have to create a scale
746 // instruction so that ConvertableToGEP will know the REAL amount we are
747 // indexing by. Note that this is never inserted into the instruction
748 // stream, so we have to delete it when we're done.
751 TempScale = BinaryOperator::create(Instruction::Mul, Index,
752 ConstantUInt::get(Type::UIntTy,
757 // Check to see if the second argument is an expression that can
758 // be converted to the appropriate size... if so, allow it.
760 std::vector<Value*> Indices;
761 const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
762 delete TempScale; // Free our temporary multiply if we made it
764 if (ElTy == 0) return false; // Cannot make conversion...
765 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
769 case Instruction::PHINode: {
770 PHINode *PN = cast<PHINode>(I);
771 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
772 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
774 return ValueConvertableToType(PN, Ty, CTMap);
777 case Instruction::Call: {
778 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
779 assert (OI != I->op_end() && "Not using value!");
780 unsigned OpNum = OI - I->op_begin();
782 // Are we trying to change the function pointer value to a new type?
784 const PointerType *PTy = dyn_cast<PointerType>(Ty);
785 if (PTy == 0) return false; // Can't convert to a non-pointer type...
786 const FunctionType *MTy = dyn_cast<FunctionType>(PTy->getElementType());
787 if (MTy == 0) return false; // Can't convert to a non ptr to function...
789 // Perform sanity checks to make sure that new function type has the
790 // correct number of arguments...
792 unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr
794 // Cannot convert to a type that requires more fixed arguments than
795 // the call provides...
797 if (NumArgs < MTy->getParamTypes().size()) return false;
799 // Unless this is a vararg function type, we cannot provide more arguments
800 // than are desired...
802 if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
805 // Okay, at this point, we know that the call and the function type match
806 // number of arguments. Now we see if we can convert the arguments
807 // themselves. Note that we do not require operands to be convertable,
808 // we can insert casts if they are convertible but not compatible. The
809 // reason for this is that we prefer to have resolved functions but casted
810 // arguments if possible.
812 const FunctionType::ParamTypes &PTs = MTy->getParamTypes();
813 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
814 if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
815 return false; // Operands must have compatible types!
817 // Okay, at this point, we know that all of the arguments can be
818 // converted. We succeed if we can change the return type if
821 return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
824 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
825 const FunctionType *MTy = cast<FunctionType>(MPtr->getElementType());
826 if (!MTy->isVarArg()) return false;
828 if ((OpNum-1) < MTy->getParamTypes().size())
829 return false; // It's not in the varargs section...
831 // If we get this far, we know the value is in the varargs section of the
832 // function! We can convert if we don't reinterpret the value...
834 return Ty->isLosslesslyConvertableTo(V->getType());
841 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
842 ValueHandle VH(VMC, V);
844 unsigned NumUses = V->use_size();
845 for (unsigned It = 0; It < NumUses; ) {
846 unsigned OldSize = NumUses;
847 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
848 NumUses = V->use_size();
849 if (NumUses == OldSize) ++It;
855 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
856 ValueMapCache &VMC) {
857 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
859 if (VMC.OperandsMapped.count(U)) return;
860 VMC.OperandsMapped.insert(U);
862 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
863 if (VMCI != VMC.ExprMap.end())
867 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
869 BasicBlock *BB = I->getParent();
870 assert(BB != 0 && "Instruction not embedded in basic block!");
871 BasicBlock::InstListType &BIL = BB->getInstList();
872 std::string Name = I->getName();
874 Instruction *Res; // Result of conversion
876 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
878 // Prevent I from being removed...
879 ValueHandle IHandle(VMC, I);
881 const Type *NewTy = NewVal->getType();
882 Constant *Dummy = (NewTy != Type::VoidTy) ?
883 Constant::getNullValue(NewTy) : 0;
885 switch (I->getOpcode()) {
886 case Instruction::Cast:
887 if (VMC.NewCasts.count(ValueHandle(VMC, I))) {
888 // This cast has already had it's value converted, causing a new cast to
889 // be created. We don't want to create YET ANOTHER cast instruction
890 // representing the original one, so just modify the operand of this cast
891 // instruction, which we know is newly created.
892 I->setOperand(0, NewVal);
893 I->setName(Name); // give I its name back
897 Res = new CastInst(NewVal, I->getType(), Name);
901 case Instruction::Add:
902 if (isa<PointerType>(NewTy)) {
903 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
904 std::vector<Value*> Indices;
905 BasicBlock::iterator It = I;
907 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
908 // If successful, convert the add to a GEP
909 //const Type *RetTy = PointerType::get(ETy);
910 // First operand is actually the given pointer...
911 Res = new GetElementPtrInst(NewVal, Indices, Name);
912 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
913 "ConvertableToGEP broken!");
919 case Instruction::Sub:
920 case Instruction::SetEQ:
921 case Instruction::SetNE: {
922 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
924 VMC.ExprMap[I] = Res; // Add node to expression eagerly
926 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
927 Value *OtherOp = I->getOperand(OtherIdx);
928 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
930 Res->setOperand(OtherIdx, NewOther);
931 Res->setOperand(!OtherIdx, NewVal);
934 case Instruction::Shl:
935 case Instruction::Shr:
936 assert(I->getOperand(0) == OldVal);
937 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
938 I->getOperand(1), Name);
941 case Instruction::Free: // Free can free any pointer type!
942 assert(I->getOperand(0) == OldVal);
943 Res = new FreeInst(NewVal);
947 case Instruction::Load: {
948 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
949 const Type *LoadedTy =
950 cast<PointerType>(NewVal->getType())->getElementType();
954 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
955 std::vector<Value*> Indices;
956 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
958 unsigned Offset = 0; // No offset, get first leaf.
959 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
960 assert(LoadedTy->isFirstClassType());
962 if (Indices.size() != 1) { // Do not generate load X, 0
963 // Insert the GEP instruction before this load.
964 Src = new GetElementPtrInst(Src, Indices, Name+".idx", I);
968 Res = new LoadInst(Src, Name);
969 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
973 case Instruction::Store: {
974 if (I->getOperand(0) == OldVal) { // Replace the source value
975 // Check to see if operand #1 has already been converted...
976 ValueMapCache::ExprMapTy::iterator VMCI =
977 VMC.ExprMap.find(I->getOperand(1));
978 if (VMCI != VMC.ExprMap.end()) {
979 // Comments describing this stuff are in the OperandConvertableToType
980 // switch statement for Store...
983 cast<PointerType>(VMCI->second->getType())->getElementType();
985 Value *SrcPtr = VMCI->second;
988 // We check that this is a struct in the initial scan...
989 const StructType *SElTy = cast<StructType>(ElTy);
991 std::vector<Value*> Indices;
992 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
995 const Type *Ty = getStructOffsetType(ElTy, Offset, Indices, false);
996 assert(Offset == 0 && "Offset changed!");
997 assert(NewTy == Ty && "Did not convert to correct type!");
999 // Insert the GEP instruction before this store.
1000 SrcPtr = new GetElementPtrInst(SrcPtr, Indices,
1001 SrcPtr->getName()+".idx", I);
1003 Res = new StoreInst(NewVal, SrcPtr);
1005 VMC.ExprMap[I] = Res;
1007 // Otherwise, we haven't converted Operand #1 over yet...
1008 const PointerType *NewPT = PointerType::get(NewTy);
1009 Res = new StoreInst(NewVal, Constant::getNullValue(NewPT));
1010 VMC.ExprMap[I] = Res;
1011 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1),
1014 } else { // Replace the source pointer
1015 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1017 Value *SrcPtr = NewVal;
1019 if (isa<StructType>(ValTy)) {
1020 std::vector<Value*> Indices;
1021 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
1023 unsigned Offset = 0;
1024 ValTy = getStructOffsetType(ValTy, Offset, Indices, false);
1026 assert(Offset == 0 && ValTy);
1028 // Insert the GEP instruction before this store.
1029 SrcPtr = new GetElementPtrInst(SrcPtr, Indices,
1030 SrcPtr->getName()+".idx", I);
1033 Res = new StoreInst(Constant::getNullValue(ValTy), SrcPtr);
1034 VMC.ExprMap[I] = Res;
1035 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
1041 case Instruction::GetElementPtr: {
1042 // Convert a one index getelementptr into just about anything that is
1045 BasicBlock::iterator It = I;
1046 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
1047 unsigned DataSize = TD.getTypeSize(OldElTy);
1048 Value *Index = I->getOperand(1);
1050 if (DataSize != 1) {
1051 // Insert a multiply of the old element type is not a unit size...
1052 Index = BinaryOperator::create(Instruction::Mul, Index,
1053 ConstantUInt::get(Type::UIntTy, DataSize),
1057 // Perform the conversion now...
1059 std::vector<Value*> Indices;
1060 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
1061 assert(ElTy != 0 && "GEP Conversion Failure!");
1062 Res = new GetElementPtrInst(NewVal, Indices, Name);
1063 assert(Res->getType() == PointerType::get(ElTy) &&
1064 "ConvertableToGet failed!");
1067 if (I->getType() == PointerType::get(Type::SByteTy)) {
1068 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1069 // anything that is a pointer type...
1071 BasicBlock::iterator It = I;
1073 // Check to see if the second argument is an expression that can
1074 // be converted to the appropriate size... if so, allow it.
1076 std::vector<Value*> Indices;
1077 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
1079 assert(ElTy != 0 && "GEP Conversion Failure!");
1081 Res = new GetElementPtrInst(NewVal, Indices, Name);
1083 // Convert a getelementptr ulong * %reg123, uint %N
1084 // to getelementptr long * %reg123, uint %N
1085 // ... where the type must simply stay the same size...
1087 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
1088 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
1089 Res = new GetElementPtrInst(NewVal, Indices, Name);
1094 case Instruction::PHINode: {
1095 PHINode *OldPN = cast<PHINode>(I);
1096 PHINode *NewPN = new PHINode(NewTy, Name);
1097 VMC.ExprMap[I] = NewPN;
1099 while (OldPN->getNumOperands()) {
1100 BasicBlock *BB = OldPN->getIncomingBlock(0);
1101 Value *OldVal = OldPN->getIncomingValue(0);
1102 OldPN->removeIncomingValue(BB);
1103 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
1104 NewPN->addIncoming(V, BB);
1110 case Instruction::Call: {
1111 Value *Meth = I->getOperand(0);
1112 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1114 if (Meth == OldVal) { // Changing the function pointer?
1115 const PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1116 const FunctionType *NewTy = cast<FunctionType>(NewPTy->getElementType());
1117 const FunctionType::ParamTypes &PTs = NewTy->getParamTypes();
1119 // Get an iterator to the call instruction so that we can insert casts for
1120 // operands if needbe. Note that we do not require operands to be
1121 // convertable, we can insert casts if they are convertible but not
1122 // compatible. The reason for this is that we prefer to have resolved
1123 // functions but casted arguments if possible.
1125 BasicBlock::iterator It = I;
1127 // Convert over all of the call operands to their new types... but only
1128 // convert over the part that is not in the vararg section of the call.
1130 for (unsigned i = 0; i < PTs.size(); ++i)
1131 if (Params[i]->getType() != PTs[i]) {
1132 // Create a cast to convert it to the right type, we know that this
1133 // is a lossless cast...
1135 Params[i] = new CastInst(Params[i], PTs[i], "call.resolve.cast", It);
1137 Meth = NewVal; // Update call destination to new value
1139 } else { // Changing an argument, must be in vararg area
1140 std::vector<Value*>::iterator OI =
1141 find(Params.begin(), Params.end(), OldVal);
1142 assert (OI != Params.end() && "Not using value!");
1147 Res = new CallInst(Meth, Params, Name);
1151 assert(0 && "Expression convertable, but don't know how to convert?");
1155 // If the instruction was newly created, insert it into the instruction
1158 BasicBlock::iterator It = I;
1159 assert(It != BIL.end() && "Instruction not in own basic block??");
1160 BIL.insert(It, Res); // Keep It pointing to old instruction
1162 DEBUG(cerr << "COT CREATED: " << (void*)Res << " " << Res
1163 << "In: " << (void*)I << " " << I << "Out: " << (void*)Res
1166 // Add the instruction to the expression map
1167 VMC.ExprMap[I] = Res;
1169 if (I->getType() != Res->getType())
1170 ConvertValueToNewType(I, Res, VMC);
1172 for (unsigned It = 0; It < I->use_size(); ) {
1173 User *Use = *(I->use_begin()+It);
1174 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1177 Use->replaceUsesOfWith(I, Res);
1180 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1182 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1187 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1188 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1189 //DEBUG(cerr << "VH AQUIRING: " << (void*)V << " " << V);
1190 Operands.push_back(Use(V, this));
1193 ValueHandle::ValueHandle(const ValueHandle &VH)
1194 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VH.Cache) {
1195 //DEBUG(cerr << "VH AQUIRING: " << (void*)V << " " << V);
1196 Operands.push_back(Use((Value*)VH.getOperand(0), this));
1199 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1200 if (!I || !I->use_empty()) return;
1202 assert(I->getParent() && "Inst not in basic block!");
1204 //DEBUG(cerr << "VH DELETING: " << (void*)I << " " << I);
1206 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1208 if (Instruction *U = dyn_cast<Instruction>(OI->get())) {
1210 RecursiveDelete(Cache, U);
1213 I->getParent()->getInstList().remove(I);
1215 Cache.OperandsMapped.erase(I);
1216 Cache.ExprMap.erase(I);
1220 ValueHandle::~ValueHandle() {
1221 if (Operands[0]->use_size() == 1) {
1222 Value *V = Operands[0];
1223 Operands[0] = 0; // Drop use!
1225 // Now we just need to remove the old instruction so we don't get infinite
1226 // loops. Note that we cannot use DCE because DCE won't remove a store
1227 // instruction, for example.
1229 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1231 //DEBUG(cerr << "VH RELEASING: " << (void*)Operands[0].get() << " "
1232 // << Operands[0]->use_size() << " " << Operands[0]);