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 TODO: This comment is out of date WRT arrays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 // Expression type must be holdable in a register.
163 if (!Ty->isFirstClassType())
166 ValueTypeCache::iterator CTMI = CTMap.find(V);
167 if (CTMI != CTMap.end()) return CTMI->second == Ty;
170 if (V->getType() == Ty) return true; // Expression already correct type!
172 Instruction *I = dyn_cast<Instruction>(V);
174 // It's not an instruction, check to see if it's a constant... all constants
175 // can be converted to an equivalent value (except pointers, they can't be
176 // const prop'd in general). We just ask the constant propogator to see if
177 // it can convert the value...
179 if (Constant *CPV = dyn_cast<Constant>(V))
180 if (ConstantFoldCastInstruction(CPV, Ty))
181 return true; // Don't worry about deallocating, it's a constant.
183 return false; // Otherwise, we can't convert!
186 switch (I->getOpcode()) {
187 case Instruction::Cast:
188 // We can convert the expr if the cast destination type is losslessly
189 // convertable to the requested type.
190 if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
192 // We also do not allow conversion of a cast that casts from a ptr to array
193 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
195 if (const PointerType *SPT =
196 dyn_cast<PointerType>(I->getOperand(0)->getType()))
197 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
198 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
199 if (AT->getElementType() == DPT->getElementType())
203 case Instruction::Add:
204 case Instruction::Sub:
205 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
206 !ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
209 case Instruction::Shr:
210 if (Ty->isSigned() != V->getType()->isSigned()) return false;
212 case Instruction::Shl:
213 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
217 case Instruction::Load: {
218 LoadInst *LI = cast<LoadInst>(I);
219 if (LI->hasIndices() && !AllIndicesZero(LI)) {
220 // We can't convert a load expression if it has indices... unless they are
225 if (!ExpressionConvertableToType(LI->getPointerOperand(),
226 PointerType::get(Ty), CTMap))
230 case Instruction::PHINode: {
231 PHINode *PN = cast<PHINode>(I);
232 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
233 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
238 case Instruction::Malloc:
239 if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
243 case Instruction::GetElementPtr: {
244 // GetElementPtr's are directly convertable to a pointer type if they have
245 // a number of zeros at the end. Because removing these values does not
246 // change the logical offset of the GEP, it is okay and fair to remove them.
247 // This can change this:
248 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
249 // %t2 = cast %List * * %t1 to %List *
251 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
253 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
254 const PointerType *PTy = dyn_cast<PointerType>(Ty);
255 if (!PTy) return false; // GEP must always return a pointer...
256 const Type *PVTy = PTy->getElementType();
258 // Check to see if there are zero elements that we can remove from the
259 // index array. If there are, check to see if removing them causes us to
260 // get to the right type...
262 std::vector<Value*> Indices = GEP->copyIndices();
263 const Type *BaseType = GEP->getPointerOperand()->getType();
264 const Type *ElTy = 0;
266 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
267 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
269 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
271 break; // Found a match!!
275 if (ElTy) break; // Found a number of zeros we can strip off!
277 // Otherwise, we can convert a GEP from one form to the other iff the
278 // current gep is of the form 'getelementptr sbyte*, unsigned N
279 // and we could convert this to an appropriate GEP for the new type.
281 if (GEP->getNumOperands() == 2 &&
282 GEP->getOperand(1)->getType() == Type::UIntTy &&
283 GEP->getType() == PointerType::get(Type::SByteTy)) {
285 // Do not Check to see if our incoming pointer can be converted
286 // to be a ptr to an array of the right type... because in more cases than
287 // not, it is simply not analyzable because of pointer/array
288 // discrepencies. To fix this, we will insert a cast before the GEP.
291 // Check to see if 'N' is an expression that can be converted to
292 // the appropriate size... if so, allow it.
294 std::vector<Value*> Indices;
295 const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
297 if (!ExpressionConvertableToType(I->getOperand(0),
298 PointerType::get(ElTy), CTMap))
299 return false; // Can't continue, ExConToTy might have polluted set!
304 // Otherwise, it could be that we have something like this:
305 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
306 // and want to convert it into something like this:
307 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
309 if (GEP->getNumOperands() == 2 &&
310 GEP->getOperand(1)->getType() == Type::UIntTy &&
311 TD.getTypeSize(PTy->getElementType()) ==
312 TD.getTypeSize(GEP->getType()->getElementType())) {
313 const PointerType *NewSrcTy = PointerType::get(PVTy);
314 if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
319 return false; // No match, maybe next time.
326 // Expressions are only convertable if all of the users of the expression can
327 // have this value converted. This makes use of the map to avoid infinite
330 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
331 if (!OperandConvertableToType(*It, I, Ty, CTMap))
338 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
339 if (V->getType() == Ty) return V; // Already where we need to be?
341 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
342 if (VMCI != VMC.ExprMap.end()) {
343 const Value *GV = VMCI->second;
344 const Type *GTy = VMCI->second->getType();
345 assert(VMCI->second->getType() == Ty);
347 if (Instruction *I = dyn_cast<Instruction>(V))
348 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
353 DEBUG(cerr << "CETT: " << (void*)V << " " << V);
355 Instruction *I = dyn_cast<Instruction>(V);
357 if (Constant *CPV = cast<Constant>(V)) {
358 // Constants are converted by constant folding the cast that is required.
359 // We assume here that all casts are implemented for constant prop.
360 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
361 assert(Result && "ConstantFoldCastInstruction Failed!!!");
362 assert(Result->getType() == Ty && "Const prop of cast failed!");
364 // Add the instruction to the expression map
365 VMC.ExprMap[V] = Result;
370 BasicBlock *BB = I->getParent();
371 BasicBlock::InstListType &BIL = BB->getInstList();
372 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
373 Instruction *Res; // Result of conversion
375 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
377 Constant *Dummy = Constant::getNullValue(Ty);
379 switch (I->getOpcode()) {
380 case Instruction::Cast:
381 assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0);
382 Res = new CastInst(I->getOperand(0), Ty, Name);
383 VMC.NewCasts.insert(ValueHandle(VMC, Res));
386 case Instruction::Add:
387 case Instruction::Sub:
388 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
390 VMC.ExprMap[I] = Res; // Add node to expression eagerly
392 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
393 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
396 case Instruction::Shl:
397 case Instruction::Shr:
398 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
399 I->getOperand(1), Name);
400 VMC.ExprMap[I] = Res;
401 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
404 case Instruction::Load: {
405 LoadInst *LI = cast<LoadInst>(I);
406 assert(!LI->hasIndices() || AllIndicesZero(LI));
408 Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
409 VMC.ExprMap[I] = Res;
410 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
411 PointerType::get(Ty), VMC));
412 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
413 assert(Ty == Res->getType());
414 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
418 case Instruction::PHINode: {
419 PHINode *OldPN = cast<PHINode>(I);
420 PHINode *NewPN = new PHINode(Ty, Name);
422 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
423 while (OldPN->getNumOperands()) {
424 BasicBlock *BB = OldPN->getIncomingBlock(0);
425 Value *OldVal = OldPN->getIncomingValue(0);
426 ValueHandle OldValHandle(VMC, OldVal);
427 OldPN->removeIncomingValue(BB);
428 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
429 NewPN->addIncoming(V, BB);
435 case Instruction::Malloc: {
436 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
440 case Instruction::GetElementPtr: {
441 // GetElementPtr's are directly convertable to a pointer type if they have
442 // a number of zeros at the end. Because removing these values does not
443 // change the logical offset of the GEP, it is okay and fair to remove them.
444 // This can change this:
445 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
446 // %t2 = cast %List * * %t1 to %List *
448 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
450 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
452 // Check to see if there are zero elements that we can remove from the
453 // index array. If there are, check to see if removing them causes us to
454 // get to the right type...
456 std::vector<Value*> Indices = GEP->copyIndices();
457 const Type *BaseType = GEP->getPointerOperand()->getType();
458 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
460 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
461 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
463 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
464 if (Indices.size() == 0) {
465 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
467 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
473 if (Res == 0 && GEP->getNumOperands() == 2 &&
474 GEP->getOperand(1)->getType() == Type::UIntTy &&
475 GEP->getType() == PointerType::get(Type::SByteTy)) {
477 // Otherwise, we can convert a GEP from one form to the other iff the
478 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
479 // and we could convert this to an appropriate GEP for the new type.
481 const PointerType *NewSrcTy = PointerType::get(PVTy);
482 BasicBlock::iterator It = I;
484 // Check to see if 'N' is an expression that can be converted to
485 // the appropriate size... if so, allow it.
487 std::vector<Value*> Indices;
488 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
491 assert(ElTy == PVTy && "Internal error, setup wrong!");
492 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
494 VMC.ExprMap[I] = Res;
495 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
500 // Otherwise, it could be that we have something like this:
501 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
502 // and want to convert it into something like this:
503 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
506 const PointerType *NewSrcTy = PointerType::get(PVTy);
507 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
508 GEP->copyIndices(), Name);
509 VMC.ExprMap[I] = Res;
510 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
515 assert(Res && "Didn't find match!");
516 break; // No match, maybe next time.
520 assert(0 && "Expression convertable, but don't know how to convert?");
524 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
528 // Add the instruction to the expression map
529 VMC.ExprMap[I] = Res;
531 // Expressions are only convertable if all of the users of the expression can
532 // have this value converted. This makes use of the map to avoid infinite
535 unsigned NumUses = I->use_size();
536 for (unsigned It = 0; It < NumUses; ) {
537 unsigned OldSize = NumUses;
538 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
539 NumUses = I->use_size();
540 if (NumUses == OldSize) ++It;
543 DEBUG(cerr << "ExpIn: " << (void*)I << " " << I
544 << "ExpOut: " << (void*)Res << " " << Res);
551 // ValueConvertableToType - Return true if it is possible
552 bool ValueConvertableToType(Value *V, const Type *Ty,
553 ValueTypeCache &ConvertedTypes) {
554 ValueTypeCache::iterator I = ConvertedTypes.find(V);
555 if (I != ConvertedTypes.end()) return I->second == Ty;
556 ConvertedTypes[V] = Ty;
558 // It is safe to convert the specified value to the specified type IFF all of
559 // the uses of the value can be converted to accept the new typed value.
561 if (V->getType() != Ty) {
562 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
563 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
574 // OperandConvertableToType - Return true if it is possible to convert operand
575 // V of User (instruction) U to the specified type. This is true iff it is
576 // possible to change the specified instruction to accept this. CTMap is a map
577 // of converted types, so that circular definitions will see the future type of
578 // the expression, not the static current type.
580 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
581 ValueTypeCache &CTMap) {
582 // if (V->getType() == Ty) return true; // Operand already the right type?
584 // Expression type must be holdable in a register.
585 if (!Ty->isFirstClassType())
588 Instruction *I = dyn_cast<Instruction>(U);
589 if (I == 0) return false; // We can't convert!
591 switch (I->getOpcode()) {
592 case Instruction::Cast:
593 assert(I->getOperand(0) == V);
594 // We can convert the expr if the cast destination type is losslessly
595 // convertable to the requested type.
596 // Also, do not change a cast that is a noop cast. For all intents and
597 // purposes it should be eliminated.
598 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
599 I->getType() == I->getOperand(0)->getType())
602 // Do not allow a 'cast ushort %V to uint' to have it's first operand be
603 // converted to a 'short' type. Doing so changes the way sign promotion
604 // happens, and breaks things. Only allow the cast to take place if the
605 // signedness doesn't change... or if the current cast is not a lossy
608 if (!I->getType()->isLosslesslyConvertableTo(I->getOperand(0)->getType()) &&
609 I->getOperand(0)->getType()->isSigned() != Ty->isSigned())
612 // We also do not allow conversion of a cast that casts from a ptr to array
613 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
615 if (const PointerType *SPT =
616 dyn_cast<PointerType>(I->getOperand(0)->getType()))
617 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
618 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
619 if (AT->getElementType() == DPT->getElementType())
623 case Instruction::Add:
624 if (isa<PointerType>(Ty)) {
625 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
626 std::vector<Value*> Indices;
627 if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
628 const Type *RetTy = PointerType::get(ETy);
630 // Only successful if we can convert this type to the required type
631 if (ValueConvertableToType(I, RetTy, CTMap)) {
635 // We have to return failure here because ValueConvertableToType could
636 // have polluted our map
641 case Instruction::Sub: {
642 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
643 return ValueConvertableToType(I, Ty, CTMap) &&
644 ExpressionConvertableToType(OtherOp, Ty, CTMap);
646 case Instruction::SetEQ:
647 case Instruction::SetNE: {
648 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
649 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
651 case Instruction::Shr:
652 if (Ty->isSigned() != V->getType()->isSigned()) return false;
654 case Instruction::Shl:
655 assert(I->getOperand(0) == V);
656 return ValueConvertableToType(I, Ty, CTMap);
658 case Instruction::Free:
659 assert(I->getOperand(0) == V);
660 return isa<PointerType>(Ty); // Free can free any pointer type!
662 case Instruction::Load:
663 // Cannot convert the types of any subscripts...
664 if (I->getOperand(0) != V) return false;
666 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
667 LoadInst *LI = cast<LoadInst>(I);
669 if (LI->hasIndices() && !AllIndicesZero(LI))
672 const Type *LoadedTy = PT->getElementType();
674 // They could be loading the first element of a composite type...
675 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
676 unsigned Offset = 0; // No offset, get first leaf.
677 std::vector<Value*> Indices; // Discarded...
678 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
679 assert(Offset == 0 && "Offset changed from zero???");
682 if (!LoadedTy->isFirstClassType())
685 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
688 return ValueConvertableToType(LI, LoadedTy, CTMap);
692 case Instruction::Store: {
693 StoreInst *SI = cast<StoreInst>(I);
694 if (SI->hasIndices()) return false;
696 if (V == I->getOperand(0)) {
697 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
698 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
699 // If so, check to see if it's Ty*, or, more importantly, if it is a
700 // pointer to a structure where the first element is a Ty... this code
701 // is neccesary because we might be trying to change the source and
702 // destination type of the store (they might be related) and the dest
703 // pointer type might be a pointer to structure. Below we allow pointer
704 // to structures where the 0th element is compatible with the value,
705 // now we have to support the symmetrical part of this.
707 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
709 // Already a pointer to what we want? Trivially accept...
710 if (ElTy == Ty) return true;
712 // Tricky case now, if the destination is a pointer to structure,
713 // obviously the source is not allowed to be a structure (cannot copy
714 // a whole structure at a time), so the level raiser must be trying to
715 // store into the first field. Check for this and allow it now:
717 if (const StructType *SElTy = dyn_cast<StructType>(ElTy)) {
719 std::vector<Value*> Indices;
720 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
721 assert(Offset == 0 && "Offset changed!");
722 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
723 return false; // Can only happen for {}*
725 if (ElTy == Ty) // Looks like the 0th element of structure is
726 return true; // compatible! Accept now!
728 // Otherwise we know that we can't work, so just stop trying now.
733 // Can convert the store if we can convert the pointer operand to match
734 // the new value type...
735 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
737 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
738 const Type *ElTy = PT->getElementType();
739 assert(V == I->getOperand(1));
741 if (isa<StructType>(ElTy)) {
742 // We can change the destination pointer if we can store our first
743 // argument into the first element of the structure...
746 std::vector<Value*> Indices;
747 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
748 assert(Offset == 0 && "Offset changed!");
749 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
750 return false; // Can only happen for {}*
753 // Must move the same amount of data...
754 if (!ElTy->isSized() ||
755 TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
758 // Can convert store if the incoming value is convertable...
759 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
764 case Instruction::GetElementPtr:
765 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
767 // If we have a two operand form of getelementptr, this is really little
768 // more than a simple addition. As with addition, check to see if the
769 // getelementptr instruction can be changed to index into the new type.
771 if (I->getNumOperands() == 2) {
772 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
773 unsigned DataSize = TD.getTypeSize(OldElTy);
774 Value *Index = I->getOperand(1);
775 Instruction *TempScale = 0;
777 // If the old data element is not unit sized, we have to create a scale
778 // instruction so that ConvertableToGEP will know the REAL amount we are
779 // indexing by. Note that this is never inserted into the instruction
780 // stream, so we have to delete it when we're done.
783 TempScale = BinaryOperator::create(Instruction::Mul, Index,
784 ConstantUInt::get(Type::UIntTy,
789 // Check to see if the second argument is an expression that can
790 // be converted to the appropriate size... if so, allow it.
792 std::vector<Value*> Indices;
793 const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
794 delete TempScale; // Free our temporary multiply if we made it
796 if (ElTy == 0) return false; // Cannot make conversion...
797 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
801 case Instruction::PHINode: {
802 PHINode *PN = cast<PHINode>(I);
803 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
804 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
806 return ValueConvertableToType(PN, Ty, CTMap);
809 case Instruction::Call: {
810 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
811 assert (OI != I->op_end() && "Not using value!");
812 unsigned OpNum = OI - I->op_begin();
814 // Are we trying to change the function pointer value to a new type?
816 const PointerType *PTy = dyn_cast<PointerType>(Ty);
817 if (PTy == 0) return false; // Can't convert to a non-pointer type...
818 const FunctionType *MTy = dyn_cast<FunctionType>(PTy->getElementType());
819 if (MTy == 0) return false; // Can't convert to a non ptr to function...
821 // Perform sanity checks to make sure that new function type has the
822 // correct number of arguments...
824 unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr
826 // Cannot convert to a type that requires more fixed arguments than
827 // the call provides...
829 if (NumArgs < MTy->getParamTypes().size()) return false;
831 // Unless this is a vararg function type, we cannot provide more arguments
832 // than are desired...
834 if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
837 // Okay, at this point, we know that the call and the function type match
838 // number of arguments. Now we see if we can convert the arguments
839 // themselves. Note that we do not require operands to be convertable,
840 // we can insert casts if they are convertible but not compatible. The
841 // reason for this is that we prefer to have resolved functions but casted
842 // arguments if possible.
844 const FunctionType::ParamTypes &PTs = MTy->getParamTypes();
845 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
846 if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
847 return false; // Operands must have compatible types!
849 // Okay, at this point, we know that all of the arguments can be
850 // converted. We succeed if we can change the return type if
853 return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
856 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
857 const FunctionType *MTy = cast<FunctionType>(MPtr->getElementType());
858 if (!MTy->isVarArg()) return false;
860 if ((OpNum-1) < MTy->getParamTypes().size())
861 return false; // It's not in the varargs section...
863 // If we get this far, we know the value is in the varargs section of the
864 // function! We can convert if we don't reinterpret the value...
866 return Ty->isLosslesslyConvertableTo(V->getType());
873 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
874 ValueHandle VH(VMC, V);
876 unsigned NumUses = V->use_size();
877 for (unsigned It = 0; It < NumUses; ) {
878 unsigned OldSize = NumUses;
879 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
880 NumUses = V->use_size();
881 if (NumUses == OldSize) ++It;
887 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
888 ValueMapCache &VMC) {
889 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
891 if (VMC.OperandsMapped.count(U)) return;
892 VMC.OperandsMapped.insert(U);
894 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
895 if (VMCI != VMC.ExprMap.end())
899 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
901 BasicBlock *BB = I->getParent();
902 assert(BB != 0 && "Instruction not embedded in basic block!");
903 BasicBlock::InstListType &BIL = BB->getInstList();
904 std::string Name = I->getName();
906 Instruction *Res; // Result of conversion
908 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
910 // Prevent I from being removed...
911 ValueHandle IHandle(VMC, I);
913 const Type *NewTy = NewVal->getType();
914 Constant *Dummy = (NewTy != Type::VoidTy) ?
915 Constant::getNullValue(NewTy) : 0;
917 switch (I->getOpcode()) {
918 case Instruction::Cast:
919 if (VMC.NewCasts.count(ValueHandle(VMC, I))) {
920 // This cast has already had it's value converted, causing a new cast to
921 // be created. We don't want to create YET ANOTHER cast instruction
922 // representing the original one, so just modify the operand of this cast
923 // instruction, which we know is newly created.
924 I->setOperand(0, NewVal);
925 I->setName(Name); // give I its name back
929 Res = new CastInst(NewVal, I->getType(), Name);
933 case Instruction::Add:
934 if (isa<PointerType>(NewTy)) {
935 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
936 std::vector<Value*> Indices;
937 BasicBlock::iterator It = I;
939 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
940 // If successful, convert the add to a GEP
941 //const Type *RetTy = PointerType::get(ETy);
942 // First operand is actually the given pointer...
943 Res = new GetElementPtrInst(NewVal, Indices, Name);
944 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
945 "ConvertableToGEP broken!");
951 case Instruction::Sub:
952 case Instruction::SetEQ:
953 case Instruction::SetNE: {
954 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
956 VMC.ExprMap[I] = Res; // Add node to expression eagerly
958 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
959 Value *OtherOp = I->getOperand(OtherIdx);
960 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
962 Res->setOperand(OtherIdx, NewOther);
963 Res->setOperand(!OtherIdx, NewVal);
966 case Instruction::Shl:
967 case Instruction::Shr:
968 assert(I->getOperand(0) == OldVal);
969 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
970 I->getOperand(1), Name);
973 case Instruction::Free: // Free can free any pointer type!
974 assert(I->getOperand(0) == OldVal);
975 Res = new FreeInst(NewVal);
979 case Instruction::Load: {
980 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
981 const Type *LoadedTy =
982 cast<PointerType>(NewVal->getType())->getElementType();
984 std::vector<Value*> Indices;
985 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
987 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
988 unsigned Offset = 0; // No offset, get first leaf.
989 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
991 assert(LoadedTy->isFirstClassType());
993 if (Indices.size() == 1)
994 Indices.clear(); // Do not generate load X, 0
996 Res = new LoadInst(NewVal, Indices, Name);
997 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
1001 case Instruction::Store: {
1002 if (I->getOperand(0) == OldVal) { // Replace the source value
1003 // Check to see if operand #1 has already been converted...
1004 ValueMapCache::ExprMapTy::iterator VMCI =
1005 VMC.ExprMap.find(I->getOperand(1));
1006 if (VMCI != VMC.ExprMap.end()) {
1007 // Comments describing this stuff are in the OperandConvertableToType
1008 // switch statement for Store...
1011 cast<PointerType>(VMCI->second->getType())->getElementType();
1012 if (ElTy == NewTy) {
1013 // If it happens to be converted to exactly the right type, use it
1015 Res = new StoreInst(NewVal, VMCI->second);
1017 // We check that this is a struct in the initial scan...
1018 const StructType *SElTy = cast<StructType>(ElTy);
1020 unsigned Offset = 0;
1021 std::vector<Value*> Indices;
1022 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
1023 const Type *Ty = getStructOffsetType(ElTy, Offset, Indices, false);
1024 assert(Offset == 0 && "Offset changed!");
1025 assert(NewTy == Ty && "Did not convert to correct type!");
1027 Res = new StoreInst(NewVal, VMCI->second, Indices);
1030 VMC.ExprMap[I] = Res;
1032 // Otherwise, we haven't converted Operand #1 over yet...
1033 const PointerType *NewPT = PointerType::get(NewTy);
1034 Res = new StoreInst(NewVal, Constant::getNullValue(NewPT));
1035 VMC.ExprMap[I] = Res;
1036 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1),
1039 } else { // Replace the source pointer
1040 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1041 std::vector<Value*> Indices;
1043 if (isa<StructType>(ValTy)) {
1044 unsigned Offset = 0;
1045 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
1046 ValTy = getStructOffsetType(ValTy, Offset, Indices, false);
1047 assert(Offset == 0 && ValTy);
1050 Res = new StoreInst(Constant::getNullValue(ValTy), NewVal, Indices);
1051 VMC.ExprMap[I] = Res;
1052 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
1058 case Instruction::GetElementPtr: {
1059 // Convert a one index getelementptr into just about anything that is
1062 BasicBlock::iterator It = I;
1063 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
1064 unsigned DataSize = TD.getTypeSize(OldElTy);
1065 Value *Index = I->getOperand(1);
1067 if (DataSize != 1) {
1068 // Insert a multiply of the old element type is not a unit size...
1069 Index = BinaryOperator::create(Instruction::Mul, Index,
1070 ConstantUInt::get(Type::UIntTy, DataSize));
1071 It = ++BIL.insert(It, cast<Instruction>(Index));
1074 // Perform the conversion now...
1076 std::vector<Value*> Indices;
1077 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
1078 assert(ElTy != 0 && "GEP Conversion Failure!");
1079 Res = new GetElementPtrInst(NewVal, Indices, Name);
1080 assert(Res->getType() == PointerType::get(ElTy) &&
1081 "ConvertableToGet failed!");
1084 if (I->getType() == PointerType::get(Type::SByteTy)) {
1085 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1086 // anything that is a pointer type...
1088 BasicBlock::iterator It = I;
1090 // Check to see if the second argument is an expression that can
1091 // be converted to the appropriate size... if so, allow it.
1093 std::vector<Value*> Indices;
1094 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
1096 assert(ElTy != 0 && "GEP Conversion Failure!");
1098 Res = new GetElementPtrInst(NewVal, Indices, Name);
1100 // Convert a getelementptr ulong * %reg123, uint %N
1101 // to getelementptr long * %reg123, uint %N
1102 // ... where the type must simply stay the same size...
1104 Res = new GetElementPtrInst(NewVal,
1105 cast<GetElementPtrInst>(I)->copyIndices(),
1111 case Instruction::PHINode: {
1112 PHINode *OldPN = cast<PHINode>(I);
1113 PHINode *NewPN = new PHINode(NewTy, Name);
1114 VMC.ExprMap[I] = NewPN;
1116 while (OldPN->getNumOperands()) {
1117 BasicBlock *BB = OldPN->getIncomingBlock(0);
1118 Value *OldVal = OldPN->getIncomingValue(0);
1119 OldPN->removeIncomingValue(BB);
1120 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
1121 NewPN->addIncoming(V, BB);
1127 case Instruction::Call: {
1128 Value *Meth = I->getOperand(0);
1129 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1131 if (Meth == OldVal) { // Changing the function pointer?
1132 const PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1133 const FunctionType *NewTy = cast<FunctionType>(NewPTy->getElementType());
1134 const FunctionType::ParamTypes &PTs = NewTy->getParamTypes();
1136 // Get an iterator to the call instruction so that we can insert casts for
1137 // operands if needbe. Note that we do not require operands to be
1138 // convertable, we can insert casts if they are convertible but not
1139 // compatible. The reason for this is that we prefer to have resolved
1140 // functions but casted arguments if possible.
1142 BasicBlock::iterator It = I;
1144 // Convert over all of the call operands to their new types... but only
1145 // convert over the part that is not in the vararg section of the call.
1147 for (unsigned i = 0; i < PTs.size(); ++i)
1148 if (Params[i]->getType() != PTs[i]) {
1149 // Create a cast to convert it to the right type, we know that this
1150 // is a lossless cast...
1152 Params[i] = new CastInst(Params[i], PTs[i], "call.resolve.cast");
1153 It = ++BIL.insert(It, cast<Instruction>(Params[i]));
1155 Meth = NewVal; // Update call destination to new value
1157 } else { // Changing an argument, must be in vararg area
1158 std::vector<Value*>::iterator OI =
1159 find(Params.begin(), Params.end(), OldVal);
1160 assert (OI != Params.end() && "Not using value!");
1165 Res = new CallInst(Meth, Params, Name);
1169 assert(0 && "Expression convertable, but don't know how to convert?");
1173 // If the instruction was newly created, insert it into the instruction
1176 BasicBlock::iterator It = I;
1177 assert(It != BIL.end() && "Instruction not in own basic block??");
1178 BIL.insert(It, Res); // Keep It pointing to old instruction
1180 DEBUG(cerr << "COT CREATED: " << (void*)Res << " " << Res
1181 << "In: " << (void*)I << " " << I << "Out: " << (void*)Res
1184 // Add the instruction to the expression map
1185 VMC.ExprMap[I] = Res;
1187 if (I->getType() != Res->getType())
1188 ConvertValueToNewType(I, Res, VMC);
1190 for (unsigned It = 0; It < I->use_size(); ) {
1191 User *Use = *(I->use_begin()+It);
1192 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1195 Use->replaceUsesOfWith(I, Res);
1198 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1200 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1205 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1206 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1207 //DEBUG(cerr << "VH AQUIRING: " << (void*)V << " " << V);
1208 Operands.push_back(Use(V, this));
1211 ValueHandle::ValueHandle(const ValueHandle &VH)
1212 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VH.Cache) {
1213 //DEBUG(cerr << "VH AQUIRING: " << (void*)V << " " << V);
1214 Operands.push_back(Use((Value*)VH.getOperand(0), this));
1217 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1218 if (!I || !I->use_empty()) return;
1220 assert(I->getParent() && "Inst not in basic block!");
1222 //DEBUG(cerr << "VH DELETING: " << (void*)I << " " << I);
1224 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1226 if (Instruction *U = dyn_cast<Instruction>(OI->get())) {
1228 RecursiveDelete(Cache, U);
1231 I->getParent()->getInstList().remove(I);
1233 Cache.OperandsMapped.erase(I);
1234 Cache.ExprMap.erase(I);
1238 ValueHandle::~ValueHandle() {
1239 if (Operands[0]->use_size() == 1) {
1240 Value *V = Operands[0];
1241 Operands[0] = 0; // Drop use!
1243 // Now we just need to remove the old instruction so we don't get infinite
1244 // loops. Note that we cannot use DCE because DCE won't remove a store
1245 // instruction, for example.
1247 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1249 //DEBUG(cerr << "VH RELEASING: " << (void*)Operands[0].get() << " "
1250 // << Operands[0]->use_size() << " " << Operands[0]);