1 //===- ExprTypeConvert.cpp - Code to change an LLVM Expr Type -------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the part of level raising that checks to see if it is
11 // possible to coerce an entire expression tree into a different type. If
12 // convertible, other routines from this file will do the conversion.
14 //===----------------------------------------------------------------------===//
16 #include "TransformInternals.h"
17 #include "llvm/iOther.h"
18 #include "llvm/iPHINode.h"
19 #include "llvm/iMemory.h"
20 #include "llvm/ConstantHandling.h"
21 #include "llvm/Analysis/Expressions.h"
22 #include "Support/STLExtras.h"
23 #include "Support/Debug.h"
26 static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty,
27 ValueTypeCache &ConvertedTypes,
28 const TargetData &TD);
30 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
31 ValueMapCache &VMC, const TargetData &TD);
33 // Peephole Malloc instructions: we take a look at the use chain of the
34 // malloc instruction, and try to find out if the following conditions hold:
35 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
36 // 2. The only users of the malloc are cast & add instructions
37 // 3. Of the cast instructions, there is only one destination pointer type
38 // [RTy] where the size of the pointed to object is equal to the number
39 // of bytes allocated.
41 // If these conditions hold, we convert the malloc to allocate an [RTy]
42 // element. TODO: This comment is out of date WRT arrays
44 static bool MallocConvertibleToType(MallocInst *MI, const Type *Ty,
45 ValueTypeCache &CTMap,
46 const TargetData &TD) {
47 if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
49 // Deal with the type to allocate, not the pointer type...
50 Ty = cast<PointerType>(Ty)->getElementType();
51 if (!Ty->isSized()) return false; // Can only alloc something with a size
53 // Analyze the number of bytes allocated...
54 ExprType Expr = ClassifyExpression(MI->getArraySize());
56 // Get information about the base datatype being allocated, before & after
57 int ReqTypeSize = TD.getTypeSize(Ty);
58 if (ReqTypeSize == 0) return false;
59 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
61 // Must have a scale or offset to analyze it...
62 if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
64 // Get the offset and scale of the allocation...
65 int64_t OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
66 int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) :(Expr.Var != 0);
68 // The old type might not be of unit size, take old size into consideration
70 int64_t Offset = OffsetVal * OldTypeSize;
71 int64_t Scale = ScaleVal * OldTypeSize;
73 // In order to be successful, both the scale and the offset must be a multiple
74 // of the requested data type's size.
76 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
77 Scale/ReqTypeSize*ReqTypeSize != Scale)
78 return false; // Nope.
83 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
84 const std::string &Name,
86 const TargetData &TD){
87 BasicBlock *BB = MI->getParent();
88 BasicBlock::iterator It = BB->end();
90 // Analyze the number of bytes allocated...
91 ExprType Expr = ClassifyExpression(MI->getArraySize());
93 const PointerType *AllocTy = cast<PointerType>(Ty);
94 const Type *ElType = AllocTy->getElementType();
96 unsigned DataSize = TD.getTypeSize(ElType);
97 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
99 // Get the offset and scale coefficients that we are allocating...
100 int64_t OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
101 int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var !=0);
103 // The old type might not be of unit size, take old size into consideration
105 unsigned Offset = (uint64_t)OffsetVal * OldTypeSize / DataSize;
106 unsigned Scale = (uint64_t)ScaleVal * OldTypeSize / DataSize;
108 // Locate the malloc instruction, because we may be inserting instructions
111 // If we have a scale, apply it first...
113 // Expr.Var is not necessarily unsigned right now, insert a cast now.
114 if (Expr.Var->getType() != Type::UIntTy)
115 Expr.Var = new CastInst(Expr.Var, Type::UIntTy,
116 Expr.Var->getName()+"-uint", It);
119 Expr.Var = BinaryOperator::create(Instruction::Mul, Expr.Var,
120 ConstantUInt::get(Type::UIntTy, Scale),
121 Expr.Var->getName()+"-scl", It);
124 // If we are not scaling anything, just make the offset be the "var"...
125 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
126 Offset = 0; Scale = 1;
129 // If we have an offset now, add it in...
131 assert(Expr.Var && "Var must be nonnull by now!");
132 Expr.Var = BinaryOperator::create(Instruction::Add, Expr.Var,
133 ConstantUInt::get(Type::UIntTy, Offset),
134 Expr.Var->getName()+"-off", It);
137 assert(AllocTy == Ty);
138 return new MallocInst(AllocTy->getElementType(), Expr.Var, Name);
142 // ExpressionConvertibleToType - Return true if it is possible
143 bool ExpressionConvertibleToType(Value *V, const Type *Ty,
144 ValueTypeCache &CTMap, const TargetData &TD) {
145 // Expression type must be holdable in a register.
146 if (!Ty->isFirstClassType())
149 ValueTypeCache::iterator CTMI = CTMap.find(V);
150 if (CTMI != CTMap.end()) return CTMI->second == Ty;
152 // If it's a constant... all constants can be converted to a different
153 // type. We just ask the constant propagator to see if it can convert the
156 if (Constant *CPV = dyn_cast<Constant>(V))
157 return ConstantFoldCastInstruction(CPV, Ty);
160 if (V->getType() == Ty) return true; // Expression already correct type!
162 Instruction *I = dyn_cast<Instruction>(V);
163 if (I == 0) return false; // Otherwise, we can't convert!
165 switch (I->getOpcode()) {
166 case Instruction::Cast:
167 // We can convert the expr if the cast destination type is losslessly
168 // convertible to the requested type.
169 if (!Ty->isLosslesslyConvertibleTo(I->getType())) return false;
171 // We also do not allow conversion of a cast that casts from a ptr to array
172 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
174 if (const PointerType *SPT =
175 dyn_cast<PointerType>(I->getOperand(0)->getType()))
176 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
177 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
178 if (AT->getElementType() == DPT->getElementType())
182 case Instruction::Add:
183 case Instruction::Sub:
184 if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false;
185 if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD) ||
186 !ExpressionConvertibleToType(I->getOperand(1), Ty, CTMap, TD))
189 case Instruction::Shr:
190 if (!Ty->isInteger()) return false;
191 if (Ty->isSigned() != V->getType()->isSigned()) return false;
193 case Instruction::Shl:
194 if (!Ty->isInteger()) return false;
195 if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD))
199 case Instruction::Load: {
200 LoadInst *LI = cast<LoadInst>(I);
201 if (!ExpressionConvertibleToType(LI->getPointerOperand(),
202 PointerType::get(Ty), CTMap, TD))
206 case Instruction::PHI: {
207 PHINode *PN = cast<PHINode>(I);
208 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
209 if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD))
214 case Instruction::Malloc:
215 if (!MallocConvertibleToType(cast<MallocInst>(I), Ty, CTMap, TD))
219 case Instruction::GetElementPtr: {
220 // GetElementPtr's are directly convertible to a pointer type if they have
221 // a number of zeros at the end. Because removing these values does not
222 // change the logical offset of the GEP, it is okay and fair to remove them.
223 // This can change this:
224 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
225 // %t2 = cast %List * * %t1 to %List *
227 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
229 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
230 const PointerType *PTy = dyn_cast<PointerType>(Ty);
231 if (!PTy) return false; // GEP must always return a pointer...
232 const Type *PVTy = PTy->getElementType();
234 // Check to see if there are zero elements that we can remove from the
235 // index array. If there are, check to see if removing them causes us to
236 // get to the right type...
238 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
239 const Type *BaseType = GEP->getPointerOperand()->getType();
240 const Type *ElTy = 0;
242 while (!Indices.empty() &&
243 Indices.back() == Constant::getNullValue(Indices.back()->getType())){
245 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
247 break; // Found a match!!
251 if (ElTy) break; // Found a number of zeros we can strip off!
253 // Otherwise, we can convert a GEP from one form to the other iff the
254 // current gep is of the form 'getelementptr sbyte*, long N
255 // and we could convert this to an appropriate GEP for the new type.
257 if (GEP->getNumOperands() == 2 &&
258 GEP->getOperand(1)->getType() == Type::LongTy &&
259 GEP->getType() == PointerType::get(Type::SByteTy)) {
261 // Do not Check to see if our incoming pointer can be converted
262 // to be a ptr to an array of the right type... because in more cases than
263 // not, it is simply not analyzable because of pointer/array
264 // discrepancies. To fix this, we will insert a cast before the GEP.
267 // Check to see if 'N' is an expression that can be converted to
268 // the appropriate size... if so, allow it.
270 std::vector<Value*> Indices;
271 const Type *ElTy = ConvertibleToGEP(PTy, I->getOperand(1), Indices, TD);
273 if (!ExpressionConvertibleToType(I->getOperand(0),
274 PointerType::get(ElTy), CTMap, TD))
275 return false; // Can't continue, ExConToTy might have polluted set!
280 // Otherwise, it could be that we have something like this:
281 // getelementptr [[sbyte] *] * %reg115, long %reg138 ; [sbyte]**
282 // and want to convert it into something like this:
283 // getelemenptr [[int] *] * %reg115, long %reg138 ; [int]**
285 if (GEP->getNumOperands() == 2 &&
286 GEP->getOperand(1)->getType() == Type::LongTy &&
287 PTy->getElementType()->isSized() &&
288 TD.getTypeSize(PTy->getElementType()) ==
289 TD.getTypeSize(GEP->getType()->getElementType())) {
290 const PointerType *NewSrcTy = PointerType::get(PVTy);
291 if (!ExpressionConvertibleToType(I->getOperand(0), NewSrcTy, CTMap, TD))
296 return false; // No match, maybe next time.
299 case Instruction::Call: {
300 if (isa<Function>(I->getOperand(0)))
301 return false; // Don't even try to change direct calls.
303 // If this is a function pointer, we can convert the return type if we can
304 // convert the source function pointer.
306 const PointerType *PT = cast<PointerType>(I->getOperand(0)->getType());
307 const FunctionType *FT = cast<FunctionType>(PT->getElementType());
308 std::vector<const Type *> ArgTys(FT->getParamTypes().begin(),
309 FT->getParamTypes().end());
310 const FunctionType *NewTy =
311 FunctionType::get(Ty, ArgTys, FT->isVarArg());
312 if (!ExpressionConvertibleToType(I->getOperand(0),
313 PointerType::get(NewTy), CTMap, TD))
321 // Expressions are only convertible if all of the users of the expression can
322 // have this value converted. This makes use of the map to avoid infinite
325 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
326 if (!OperandConvertibleToType(*It, I, Ty, CTMap, TD))
333 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC,
334 const TargetData &TD) {
335 if (V->getType() == Ty) return V; // Already where we need to be?
337 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
338 if (VMCI != VMC.ExprMap.end()) {
339 const Value *GV = VMCI->second;
340 const Type *GTy = VMCI->second->getType();
341 assert(VMCI->second->getType() == Ty);
343 if (Instruction *I = dyn_cast<Instruction>(V))
344 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
349 DEBUG(std::cerr << "CETT: " << (void*)V << " " << V);
351 Instruction *I = dyn_cast<Instruction>(V);
353 Constant *CPV = cast<Constant>(V);
354 // Constants are converted by constant folding the cast that is required.
355 // We assume here that all casts are implemented for constant prop.
356 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
357 assert(Result && "ConstantFoldCastInstruction Failed!!!");
358 assert(Result->getType() == Ty && "Const prop of cast failed!");
360 // Add the instruction to the expression map
361 //VMC.ExprMap[V] = Result;
366 BasicBlock *BB = I->getParent();
367 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
368 Instruction *Res; // Result of conversion
370 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
372 Constant *Dummy = Constant::getNullValue(Ty);
374 switch (I->getOpcode()) {
375 case Instruction::Cast:
376 assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0);
377 Res = new CastInst(I->getOperand(0), Ty, Name);
378 VMC.NewCasts.insert(ValueHandle(VMC, Res));
381 case Instruction::Add:
382 case Instruction::Sub:
383 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
385 VMC.ExprMap[I] = Res; // Add node to expression eagerly
387 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD));
388 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC, TD));
391 case Instruction::Shl:
392 case Instruction::Shr:
393 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
394 I->getOperand(1), Name);
395 VMC.ExprMap[I] = Res;
396 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD));
399 case Instruction::Load: {
400 LoadInst *LI = cast<LoadInst>(I);
402 Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
403 VMC.ExprMap[I] = Res;
404 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
405 PointerType::get(Ty), VMC, TD));
406 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
407 assert(Ty == Res->getType());
408 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
412 case Instruction::PHI: {
413 PHINode *OldPN = cast<PHINode>(I);
414 PHINode *NewPN = new PHINode(Ty, Name);
416 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
417 while (OldPN->getNumOperands()) {
418 BasicBlock *BB = OldPN->getIncomingBlock(0);
419 Value *OldVal = OldPN->getIncomingValue(0);
420 ValueHandle OldValHandle(VMC, OldVal);
421 OldPN->removeIncomingValue(BB, false);
422 Value *V = ConvertExpressionToType(OldVal, Ty, VMC, TD);
423 NewPN->addIncoming(V, BB);
429 case Instruction::Malloc: {
430 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC, TD);
434 case Instruction::GetElementPtr: {
435 // GetElementPtr's are directly convertible to a pointer type if they have
436 // a number of zeros at the end. Because removing these values does not
437 // change the logical offset of the GEP, it is okay and fair to remove them.
438 // This can change this:
439 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
440 // %t2 = cast %List * * %t1 to %List *
442 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
444 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
446 // Check to see if there are zero elements that we can remove from the
447 // index array. If there are, check to see if removing them causes us to
448 // get to the right type...
450 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
451 const Type *BaseType = GEP->getPointerOperand()->getType();
452 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
454 while (!Indices.empty() &&
455 Indices.back() == Constant::getNullValue(Indices.back()->getType())){
457 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
458 if (Indices.size() == 0)
459 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP CAST
461 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
466 if (Res == 0 && GEP->getNumOperands() == 2 &&
467 GEP->getOperand(1)->getType() == Type::LongTy &&
468 GEP->getType() == PointerType::get(Type::SByteTy)) {
470 // Otherwise, we can convert a GEP from one form to the other iff the
471 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
472 // and we could convert this to an appropriate GEP for the new type.
474 const PointerType *NewSrcTy = PointerType::get(PVTy);
475 BasicBlock::iterator It = I;
477 // Check to see if 'N' is an expression that can be converted to
478 // the appropriate size... if so, allow it.
480 std::vector<Value*> Indices;
481 const Type *ElTy = ConvertibleToGEP(NewSrcTy, I->getOperand(1),
484 assert(ElTy == PVTy && "Internal error, setup wrong!");
485 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
487 VMC.ExprMap[I] = Res;
488 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
493 // Otherwise, it could be that we have something like this:
494 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
495 // and want to convert it into something like this:
496 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
499 const PointerType *NewSrcTy = PointerType::get(PVTy);
500 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
501 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
503 VMC.ExprMap[I] = Res;
504 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
509 assert(Res && "Didn't find match!");
513 case Instruction::Call: {
514 assert(!isa<Function>(I->getOperand(0)));
516 // If this is a function pointer, we can convert the return type if we can
517 // convert the source function pointer.
519 const PointerType *PT = cast<PointerType>(I->getOperand(0)->getType());
520 const FunctionType *FT = cast<FunctionType>(PT->getElementType());
521 std::vector<const Type *> ArgTys(FT->getParamTypes().begin(),
522 FT->getParamTypes().end());
523 const FunctionType *NewTy =
524 FunctionType::get(Ty, ArgTys, FT->isVarArg());
525 const PointerType *NewPTy = PointerType::get(NewTy);
526 if (Ty == Type::VoidTy)
527 Name = ""; // Make sure not to name calls that now return void!
529 Res = new CallInst(Constant::getNullValue(NewPTy),
530 std::vector<Value*>(I->op_begin()+1, I->op_end()),
532 VMC.ExprMap[I] = Res;
533 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),NewPTy,VMC,TD));
537 assert(0 && "Expression convertible, but don't know how to convert?");
541 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
543 BB->getInstList().insert(I, Res);
545 // Add the instruction to the expression map
546 VMC.ExprMap[I] = Res;
549 unsigned NumUses = I->use_size();
550 for (unsigned It = 0; It < NumUses; ) {
551 unsigned OldSize = NumUses;
552 Value::use_iterator UI = I->use_begin();
553 std::advance(UI, It);
554 ConvertOperandToType(*UI, I, Res, VMC, TD);
555 NumUses = I->use_size();
556 if (NumUses == OldSize) ++It;
559 DEBUG(std::cerr << "ExpIn: " << (void*)I << " " << I
560 << "ExpOut: " << (void*)Res << " " << Res);
567 // ValueConvertibleToType - Return true if it is possible
568 bool ValueConvertibleToType(Value *V, const Type *Ty,
569 ValueTypeCache &ConvertedTypes,
570 const TargetData &TD) {
571 ValueTypeCache::iterator I = ConvertedTypes.find(V);
572 if (I != ConvertedTypes.end()) return I->second == Ty;
573 ConvertedTypes[V] = Ty;
575 // It is safe to convert the specified value to the specified type IFF all of
576 // the uses of the value can be converted to accept the new typed value.
578 if (V->getType() != Ty) {
579 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
580 if (!OperandConvertibleToType(*I, V, Ty, ConvertedTypes, TD))
591 // OperandConvertibleToType - Return true if it is possible to convert operand
592 // V of User (instruction) U to the specified type. This is true iff it is
593 // possible to change the specified instruction to accept this. CTMap is a map
594 // of converted types, so that circular definitions will see the future type of
595 // the expression, not the static current type.
597 static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty,
598 ValueTypeCache &CTMap,
599 const TargetData &TD) {
600 // if (V->getType() == Ty) return true; // Operand already the right type?
602 // Expression type must be holdable in a register.
603 if (!Ty->isFirstClassType())
606 Instruction *I = dyn_cast<Instruction>(U);
607 if (I == 0) return false; // We can't convert!
609 switch (I->getOpcode()) {
610 case Instruction::Cast:
611 assert(I->getOperand(0) == V);
612 // We can convert the expr if the cast destination type is losslessly
613 // convertible to the requested type.
614 // Also, do not change a cast that is a noop cast. For all intents and
615 // purposes it should be eliminated.
616 if (!Ty->isLosslesslyConvertibleTo(I->getOperand(0)->getType()) ||
617 I->getType() == I->getOperand(0)->getType())
620 // Do not allow a 'cast ushort %V to uint' to have it's first operand be
621 // converted to a 'short' type. Doing so changes the way sign promotion
622 // happens, and breaks things. Only allow the cast to take place if the
623 // signedness doesn't change... or if the current cast is not a lossy
626 if (!I->getType()->isLosslesslyConvertibleTo(I->getOperand(0)->getType()) &&
627 I->getOperand(0)->getType()->isSigned() != Ty->isSigned())
630 // We also do not allow conversion of a cast that casts from a ptr to array
631 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
633 if (const PointerType *SPT =
634 dyn_cast<PointerType>(I->getOperand(0)->getType()))
635 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
636 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
637 if (AT->getElementType() == DPT->getElementType())
641 case Instruction::Add:
642 if (isa<PointerType>(Ty)) {
643 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
644 std::vector<Value*> Indices;
645 if (const Type *ETy = ConvertibleToGEP(Ty, IndexVal, Indices, TD)) {
646 const Type *RetTy = PointerType::get(ETy);
648 // Only successful if we can convert this type to the required type
649 if (ValueConvertibleToType(I, RetTy, CTMap, TD)) {
653 // We have to return failure here because ValueConvertibleToType could
654 // have polluted our map
659 case Instruction::Sub: {
660 if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false;
662 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
663 return ValueConvertibleToType(I, Ty, CTMap, TD) &&
664 ExpressionConvertibleToType(OtherOp, Ty, CTMap, TD);
666 case Instruction::SetEQ:
667 case Instruction::SetNE: {
668 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
669 return ExpressionConvertibleToType(OtherOp, Ty, CTMap, TD);
671 case Instruction::Shr:
672 if (Ty->isSigned() != V->getType()->isSigned()) return false;
674 case Instruction::Shl:
675 if (I->getOperand(1) == V) return false; // Cannot change shift amount type
676 if (!Ty->isInteger()) return false;
677 return ValueConvertibleToType(I, Ty, CTMap, TD);
679 case Instruction::Free:
680 assert(I->getOperand(0) == V);
681 return isa<PointerType>(Ty); // Free can free any pointer type!
683 case Instruction::Load:
684 // Cannot convert the types of any subscripts...
685 if (I->getOperand(0) != V) return false;
687 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
688 LoadInst *LI = cast<LoadInst>(I);
690 const Type *LoadedTy = PT->getElementType();
692 // They could be loading the first element of a composite type...
693 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
694 unsigned Offset = 0; // No offset, get first leaf.
695 std::vector<Value*> Indices; // Discarded...
696 LoadedTy = getStructOffsetType(CT, Offset, Indices, TD, false);
697 assert(Offset == 0 && "Offset changed from zero???");
700 if (!LoadedTy->isFirstClassType())
703 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
706 return ValueConvertibleToType(LI, LoadedTy, CTMap, TD);
710 case Instruction::Store: {
711 StoreInst *SI = cast<StoreInst>(I);
713 if (V == I->getOperand(0)) {
714 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
715 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
716 // If so, check to see if it's Ty*, or, more importantly, if it is a
717 // pointer to a structure where the first element is a Ty... this code
718 // is necessary because we might be trying to change the source and
719 // destination type of the store (they might be related) and the dest
720 // pointer type might be a pointer to structure. Below we allow pointer
721 // to structures where the 0th element is compatible with the value,
722 // now we have to support the symmetrical part of this.
724 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
726 // Already a pointer to what we want? Trivially accept...
727 if (ElTy == Ty) return true;
729 // Tricky case now, if the destination is a pointer to structure,
730 // obviously the source is not allowed to be a structure (cannot copy
731 // a whole structure at a time), so the level raiser must be trying to
732 // store into the first field. Check for this and allow it now:
734 if (const StructType *SElTy = dyn_cast<StructType>(ElTy)) {
736 std::vector<Value*> Indices;
737 ElTy = getStructOffsetType(ElTy, Offset, Indices, TD, false);
738 assert(Offset == 0 && "Offset changed!");
739 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
740 return false; // Can only happen for {}*
742 if (ElTy == Ty) // Looks like the 0th element of structure is
743 return true; // compatible! Accept now!
745 // Otherwise we know that we can't work, so just stop trying now.
750 // Can convert the store if we can convert the pointer operand to match
751 // the new value type...
752 return ExpressionConvertibleToType(I->getOperand(1), PointerType::get(Ty),
754 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
755 const Type *ElTy = PT->getElementType();
756 assert(V == I->getOperand(1));
758 if (isa<StructType>(ElTy)) {
759 // We can change the destination pointer if we can store our first
760 // argument into the first element of the structure...
763 std::vector<Value*> Indices;
764 ElTy = getStructOffsetType(ElTy, Offset, Indices, TD, false);
765 assert(Offset == 0 && "Offset changed!");
766 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
767 return false; // Can only happen for {}*
770 // Must move the same amount of data...
771 if (!ElTy->isSized() ||
772 TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
775 // Can convert store if the incoming value is convertible...
776 return ExpressionConvertibleToType(I->getOperand(0), ElTy, CTMap, TD);
781 case Instruction::GetElementPtr:
782 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
784 // If we have a two operand form of getelementptr, this is really little
785 // more than a simple addition. As with addition, check to see if the
786 // getelementptr instruction can be changed to index into the new type.
788 if (I->getNumOperands() == 2) {
789 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
790 unsigned DataSize = TD.getTypeSize(OldElTy);
791 Value *Index = I->getOperand(1);
792 Instruction *TempScale = 0;
794 // If the old data element is not unit sized, we have to create a scale
795 // instruction so that ConvertibleToGEP will know the REAL amount we are
796 // indexing by. Note that this is never inserted into the instruction
797 // stream, so we have to delete it when we're done.
800 TempScale = BinaryOperator::create(Instruction::Mul, Index,
801 ConstantSInt::get(Type::LongTy,
806 // Check to see if the second argument is an expression that can
807 // be converted to the appropriate size... if so, allow it.
809 std::vector<Value*> Indices;
810 const Type *ElTy = ConvertibleToGEP(Ty, Index, Indices, TD);
811 delete TempScale; // Free our temporary multiply if we made it
813 if (ElTy == 0) return false; // Cannot make conversion...
814 return ValueConvertibleToType(I, PointerType::get(ElTy), CTMap, TD);
818 case Instruction::PHI: {
819 PHINode *PN = cast<PHINode>(I);
820 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
821 if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD))
823 return ValueConvertibleToType(PN, Ty, CTMap, TD);
826 case Instruction::Call: {
827 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
828 assert (OI != I->op_end() && "Not using value!");
829 unsigned OpNum = OI - I->op_begin();
831 // Are we trying to change the function pointer value to a new type?
833 const PointerType *PTy = dyn_cast<PointerType>(Ty);
834 if (PTy == 0) return false; // Can't convert to a non-pointer type...
835 const FunctionType *FTy = dyn_cast<FunctionType>(PTy->getElementType());
836 if (FTy == 0) return false; // Can't convert to a non ptr to function...
838 // Do not allow converting to a call where all of the operands are ...'s
839 if (FTy->getNumParams() == 0 && FTy->isVarArg())
840 return false; // Do not permit this conversion!
842 // Perform sanity checks to make sure that new function type has the
843 // correct number of arguments...
845 unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr
847 // Cannot convert to a type that requires more fixed arguments than
848 // the call provides...
850 if (NumArgs < FTy->getNumParams()) return false;
852 // Unless this is a vararg function type, we cannot provide more arguments
853 // than are desired...
855 if (!FTy->isVarArg() && NumArgs > FTy->getNumParams())
858 // Okay, at this point, we know that the call and the function type match
859 // number of arguments. Now we see if we can convert the arguments
860 // themselves. Note that we do not require operands to be convertible,
861 // we can insert casts if they are convertible but not compatible. The
862 // reason for this is that we prefer to have resolved functions but casted
863 // arguments if possible.
865 const FunctionType::ParamTypes &PTs = FTy->getParamTypes();
866 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
867 if (!PTs[i]->isLosslesslyConvertibleTo(I->getOperand(i+1)->getType()))
868 return false; // Operands must have compatible types!
870 // Okay, at this point, we know that all of the arguments can be
871 // converted. We succeed if we can change the return type if
874 return ValueConvertibleToType(I, FTy->getReturnType(), CTMap, TD);
877 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
878 const FunctionType *FTy = cast<FunctionType>(MPtr->getElementType());
879 if (!FTy->isVarArg()) return false;
881 if ((OpNum-1) < FTy->getParamTypes().size())
882 return false; // It's not in the varargs section...
884 // If we get this far, we know the value is in the varargs section of the
885 // function! We can convert if we don't reinterpret the value...
887 return Ty->isLosslesslyConvertibleTo(V->getType());
894 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC,
895 const TargetData &TD) {
896 ValueHandle VH(VMC, V);
898 unsigned NumUses = V->use_size();
899 for (unsigned It = 0; It < NumUses; ) {
900 unsigned OldSize = NumUses;
901 Value::use_iterator UI = V->use_begin();
902 std::advance(UI, It);
903 ConvertOperandToType(*UI, V, NewVal, VMC, TD);
904 NumUses = V->use_size();
905 if (NumUses == OldSize) ++It;
911 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
912 ValueMapCache &VMC, const TargetData &TD) {
913 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
915 if (VMC.OperandsMapped.count(U)) return;
916 VMC.OperandsMapped.insert(U);
918 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
919 if (VMCI != VMC.ExprMap.end())
923 Instruction *I = cast<Instruction>(U); // Only Instructions convertible
925 BasicBlock *BB = I->getParent();
926 assert(BB != 0 && "Instruction not embedded in basic block!");
927 std::string Name = I->getName();
929 Instruction *Res; // Result of conversion
931 //std::cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I
932 // << "BB Before: " << BB << endl;
934 // Prevent I from being removed...
935 ValueHandle IHandle(VMC, I);
937 const Type *NewTy = NewVal->getType();
938 Constant *Dummy = (NewTy != Type::VoidTy) ?
939 Constant::getNullValue(NewTy) : 0;
941 switch (I->getOpcode()) {
942 case Instruction::Cast:
943 if (VMC.NewCasts.count(ValueHandle(VMC, I))) {
944 // This cast has already had it's value converted, causing a new cast to
945 // be created. We don't want to create YET ANOTHER cast instruction
946 // representing the original one, so just modify the operand of this cast
947 // instruction, which we know is newly created.
948 I->setOperand(0, NewVal);
949 I->setName(Name); // give I its name back
953 Res = new CastInst(NewVal, I->getType(), Name);
957 case Instruction::Add:
958 if (isa<PointerType>(NewTy)) {
959 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
960 std::vector<Value*> Indices;
961 BasicBlock::iterator It = I;
963 if (const Type *ETy = ConvertibleToGEP(NewTy, IndexVal, Indices, TD,&It)){
964 // If successful, convert the add to a GEP
965 //const Type *RetTy = PointerType::get(ETy);
966 // First operand is actually the given pointer...
967 Res = new GetElementPtrInst(NewVal, Indices, Name);
968 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
969 "ConvertibleToGEP broken!");
975 case Instruction::Sub:
976 case Instruction::SetEQ:
977 case Instruction::SetNE: {
978 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
980 VMC.ExprMap[I] = Res; // Add node to expression eagerly
982 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
983 Value *OtherOp = I->getOperand(OtherIdx);
984 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC, TD);
986 Res->setOperand(OtherIdx, NewOther);
987 Res->setOperand(!OtherIdx, NewVal);
990 case Instruction::Shl:
991 case Instruction::Shr:
992 assert(I->getOperand(0) == OldVal);
993 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
994 I->getOperand(1), Name);
997 case Instruction::Free: // Free can free any pointer type!
998 assert(I->getOperand(0) == OldVal);
999 Res = new FreeInst(NewVal);
1003 case Instruction::Load: {
1004 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
1005 const Type *LoadedTy =
1006 cast<PointerType>(NewVal->getType())->getElementType();
1008 Value *Src = NewVal;
1010 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
1011 std::vector<Value*> Indices;
1012 Indices.push_back(ConstantSInt::get(Type::LongTy, 0));
1014 unsigned Offset = 0; // No offset, get first leaf.
1015 LoadedTy = getStructOffsetType(CT, Offset, Indices, TD, false);
1016 assert(LoadedTy->isFirstClassType());
1018 if (Indices.size() != 1) { // Do not generate load X, 0
1019 // Insert the GEP instruction before this load.
1020 Src = new GetElementPtrInst(Src, Indices, Name+".idx", I);
1024 Res = new LoadInst(Src, Name);
1025 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
1029 case Instruction::Store: {
1030 if (I->getOperand(0) == OldVal) { // Replace the source value
1031 // Check to see if operand #1 has already been converted...
1032 ValueMapCache::ExprMapTy::iterator VMCI =
1033 VMC.ExprMap.find(I->getOperand(1));
1034 if (VMCI != VMC.ExprMap.end()) {
1035 // Comments describing this stuff are in the OperandConvertibleToType
1036 // switch statement for Store...
1039 cast<PointerType>(VMCI->second->getType())->getElementType();
1041 Value *SrcPtr = VMCI->second;
1043 if (ElTy != NewTy) {
1044 // We check that this is a struct in the initial scan...
1045 const StructType *SElTy = cast<StructType>(ElTy);
1047 std::vector<Value*> Indices;
1048 Indices.push_back(Constant::getNullValue(Type::LongTy));
1050 unsigned Offset = 0;
1051 const Type *Ty = getStructOffsetType(ElTy, Offset, Indices, TD,false);
1052 assert(Offset == 0 && "Offset changed!");
1053 assert(NewTy == Ty && "Did not convert to correct type!");
1055 // Insert the GEP instruction before this store.
1056 SrcPtr = new GetElementPtrInst(SrcPtr, Indices,
1057 SrcPtr->getName()+".idx", I);
1059 Res = new StoreInst(NewVal, SrcPtr);
1061 VMC.ExprMap[I] = Res;
1063 // Otherwise, we haven't converted Operand #1 over yet...
1064 const PointerType *NewPT = PointerType::get(NewTy);
1065 Res = new StoreInst(NewVal, Constant::getNullValue(NewPT));
1066 VMC.ExprMap[I] = Res;
1067 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1),
1070 } else { // Replace the source pointer
1071 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1073 Value *SrcPtr = NewVal;
1075 if (isa<StructType>(ValTy)) {
1076 std::vector<Value*> Indices;
1077 Indices.push_back(Constant::getNullValue(Type::LongTy));
1079 unsigned Offset = 0;
1080 ValTy = getStructOffsetType(ValTy, Offset, Indices, TD, false);
1082 assert(Offset == 0 && ValTy);
1084 // Insert the GEP instruction before this store.
1085 SrcPtr = new GetElementPtrInst(SrcPtr, Indices,
1086 SrcPtr->getName()+".idx", I);
1089 Res = new StoreInst(Constant::getNullValue(ValTy), SrcPtr);
1090 VMC.ExprMap[I] = Res;
1091 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
1098 case Instruction::GetElementPtr: {
1099 // Convert a one index getelementptr into just about anything that is
1102 BasicBlock::iterator It = I;
1103 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
1104 unsigned DataSize = TD.getTypeSize(OldElTy);
1105 Value *Index = I->getOperand(1);
1107 if (DataSize != 1) {
1108 // Insert a multiply of the old element type is not a unit size...
1109 Index = BinaryOperator::create(Instruction::Mul, Index,
1110 ConstantSInt::get(Type::LongTy, DataSize),
1114 // Perform the conversion now...
1116 std::vector<Value*> Indices;
1117 const Type *ElTy = ConvertibleToGEP(NewVal->getType(),Index,Indices,TD,&It);
1118 assert(ElTy != 0 && "GEP Conversion Failure!");
1119 Res = new GetElementPtrInst(NewVal, Indices, Name);
1120 assert(Res->getType() == PointerType::get(ElTy) &&
1121 "ConvertibleToGet failed!");
1124 if (I->getType() == PointerType::get(Type::SByteTy)) {
1125 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1126 // anything that is a pointer type...
1128 BasicBlock::iterator It = I;
1130 // Check to see if the second argument is an expression that can
1131 // be converted to the appropriate size... if so, allow it.
1133 std::vector<Value*> Indices;
1134 const Type *ElTy = ConvertibleToGEP(NewVal->getType(), I->getOperand(1),
1136 assert(ElTy != 0 && "GEP Conversion Failure!");
1138 Res = new GetElementPtrInst(NewVal, Indices, Name);
1140 // Convert a getelementptr ulong * %reg123, uint %N
1141 // to getelementptr long * %reg123, uint %N
1142 // ... where the type must simply stay the same size...
1144 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
1145 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
1146 Res = new GetElementPtrInst(NewVal, Indices, Name);
1151 case Instruction::PHI: {
1152 PHINode *OldPN = cast<PHINode>(I);
1153 PHINode *NewPN = new PHINode(NewTy, Name);
1154 VMC.ExprMap[I] = NewPN;
1156 while (OldPN->getNumOperands()) {
1157 BasicBlock *BB = OldPN->getIncomingBlock(0);
1158 Value *OldVal = OldPN->getIncomingValue(0);
1159 OldPN->removeIncomingValue(BB, false);
1160 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC, TD);
1161 NewPN->addIncoming(V, BB);
1167 case Instruction::Call: {
1168 Value *Meth = I->getOperand(0);
1169 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1171 if (Meth == OldVal) { // Changing the function pointer?
1172 const PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1173 const FunctionType *NewTy = cast<FunctionType>(NewPTy->getElementType());
1174 const FunctionType::ParamTypes &PTs = NewTy->getParamTypes();
1176 if (NewTy->getReturnType() == Type::VoidTy)
1177 Name = ""; // Make sure not to name a void call!
1179 // Get an iterator to the call instruction so that we can insert casts for
1180 // operands if need be. Note that we do not require operands to be
1181 // convertible, we can insert casts if they are convertible but not
1182 // compatible. The reason for this is that we prefer to have resolved
1183 // functions but casted arguments if possible.
1185 BasicBlock::iterator It = I;
1187 // Convert over all of the call operands to their new types... but only
1188 // convert over the part that is not in the vararg section of the call.
1190 for (unsigned i = 0; i < PTs.size(); ++i)
1191 if (Params[i]->getType() != PTs[i]) {
1192 // Create a cast to convert it to the right type, we know that this
1193 // is a lossless cast...
1195 Params[i] = new CastInst(Params[i], PTs[i], "callarg.cast." +
1196 Params[i]->getName(), It);
1198 Meth = NewVal; // Update call destination to new value
1200 } else { // Changing an argument, must be in vararg area
1201 std::vector<Value*>::iterator OI =
1202 find(Params.begin(), Params.end(), OldVal);
1203 assert (OI != Params.end() && "Not using value!");
1208 Res = new CallInst(Meth, Params, Name);
1212 assert(0 && "Expression convertible, but don't know how to convert?");
1216 // If the instruction was newly created, insert it into the instruction
1219 BasicBlock::iterator It = I;
1220 assert(It != BB->end() && "Instruction not in own basic block??");
1221 BB->getInstList().insert(It, Res); // Keep It pointing to old instruction
1223 DEBUG(std::cerr << "COT CREATED: " << (void*)Res << " " << Res
1224 << "In: " << (void*)I << " " << I << "Out: " << (void*)Res
1227 // Add the instruction to the expression map
1228 VMC.ExprMap[I] = Res;
1230 if (I->getType() != Res->getType())
1231 ConvertValueToNewType(I, Res, VMC, TD);
1233 bool FromStart = true;
1234 Value::use_iterator UI;
1236 if (FromStart) UI = I->use_begin();
1237 if (UI == I->use_end()) break;
1239 if (isa<ValueHandle>(*UI)) {
1244 if (!FromStart) --UI;
1245 U->replaceUsesOfWith(I, Res);
1246 if (!FromStart) ++UI;
1253 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1254 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1255 //DEBUG(std::cerr << "VH AQUIRING: " << (void*)V << " " << V);
1256 Operands.push_back(Use(V, this));
1259 ValueHandle::ValueHandle(const ValueHandle &VH)
1260 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VH.Cache) {
1261 //DEBUG(std::cerr << "VH AQUIRING: " << (void*)V << " " << V);
1262 Operands.push_back(Use((Value*)VH.getOperand(0), this));
1265 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1266 if (!I || !I->use_empty()) return;
1268 assert(I->getParent() && "Inst not in basic block!");
1270 //DEBUG(std::cerr << "VH DELETING: " << (void*)I << " " << I);
1272 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1274 if (Instruction *U = dyn_cast<Instruction>(OI)) {
1276 RecursiveDelete(Cache, U);
1279 I->getParent()->getInstList().remove(I);
1281 Cache.OperandsMapped.erase(I);
1282 Cache.ExprMap.erase(I);
1286 ValueHandle::~ValueHandle() {
1287 if (Operands[0]->hasOneUse()) {
1288 Value *V = Operands[0];
1289 Operands[0] = 0; // Drop use!
1291 // Now we just need to remove the old instruction so we don't get infinite
1292 // loops. Note that we cannot use DCE because DCE won't remove a store
1293 // instruction, for example.
1295 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1297 //DEBUG(std::cerr << "VH RELEASING: " << (void*)Operands[0].get() << " "
1298 // << Operands[0]->use_size() << " " << Operands[0]);