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/Constants.h"
18 #include "llvm/iOther.h"
19 #include "llvm/iPHINode.h"
20 #include "llvm/iMemory.h"
22 #include "llvm/Analysis/Expressions.h"
23 #include "Support/STLExtras.h"
24 #include "Support/Debug.h"
28 static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty,
29 ValueTypeCache &ConvertedTypes,
30 const TargetData &TD);
32 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
33 ValueMapCache &VMC, const TargetData &TD);
35 // Peephole Malloc instructions: we take a look at the use chain of the
36 // malloc instruction, and try to find out if the following conditions hold:
37 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
38 // 2. The only users of the malloc are cast & add instructions
39 // 3. Of the cast instructions, there is only one destination pointer type
40 // [RTy] where the size of the pointed to object is equal to the number
41 // of bytes allocated.
43 // If these conditions hold, we convert the malloc to allocate an [RTy]
44 // element. TODO: This comment is out of date WRT arrays
46 static bool MallocConvertibleToType(MallocInst *MI, const Type *Ty,
47 ValueTypeCache &CTMap,
48 const TargetData &TD) {
49 if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
51 // Deal with the type to allocate, not the pointer type...
52 Ty = cast<PointerType>(Ty)->getElementType();
53 if (!Ty->isSized()) return false; // Can only alloc something with a size
55 // Analyze the number of bytes allocated...
56 ExprType Expr = ClassifyExpr(MI->getArraySize());
58 // Get information about the base datatype being allocated, before & after
59 int ReqTypeSize = TD.getTypeSize(Ty);
60 if (ReqTypeSize == 0) return false;
61 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
63 // Must have a scale or offset to analyze it...
64 if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
66 // Get the offset and scale of the allocation...
67 int64_t OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
68 int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) :(Expr.Var != 0);
70 // The old type might not be of unit size, take old size into consideration
72 int64_t Offset = OffsetVal * OldTypeSize;
73 int64_t Scale = ScaleVal * OldTypeSize;
75 // In order to be successful, both the scale and the offset must be a multiple
76 // of the requested data type's size.
78 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
79 Scale/ReqTypeSize*ReqTypeSize != Scale)
80 return false; // Nope.
85 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
86 const std::string &Name,
88 const TargetData &TD){
89 BasicBlock *BB = MI->getParent();
90 BasicBlock::iterator It = BB->end();
92 // Analyze the number of bytes allocated...
93 ExprType Expr = ClassifyExpr(MI->getArraySize());
95 const PointerType *AllocTy = cast<PointerType>(Ty);
96 const Type *ElType = AllocTy->getElementType();
98 unsigned DataSize = TD.getTypeSize(ElType);
99 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
101 // Get the offset and scale coefficients that we are allocating...
102 int64_t OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
103 int64_t ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var !=0);
105 // The old type might not be of unit size, take old size into consideration
107 unsigned Offset = (uint64_t)OffsetVal * OldTypeSize / DataSize;
108 unsigned Scale = (uint64_t)ScaleVal * OldTypeSize / DataSize;
110 // Locate the malloc instruction, because we may be inserting instructions
113 // If we have a scale, apply it first...
115 // Expr.Var is not necessarily unsigned right now, insert a cast now.
116 if (Expr.Var->getType() != Type::UIntTy)
117 Expr.Var = new CastInst(Expr.Var, Type::UIntTy,
118 Expr.Var->getName()+"-uint", It);
121 Expr.Var = BinaryOperator::create(Instruction::Mul, Expr.Var,
122 ConstantUInt::get(Type::UIntTy, Scale),
123 Expr.Var->getName()+"-scl", It);
126 // If we are not scaling anything, just make the offset be the "var"...
127 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
128 Offset = 0; Scale = 1;
131 // If we have an offset now, add it in...
133 assert(Expr.Var && "Var must be nonnull by now!");
134 Expr.Var = BinaryOperator::create(Instruction::Add, Expr.Var,
135 ConstantUInt::get(Type::UIntTy, Offset),
136 Expr.Var->getName()+"-off", It);
139 assert(AllocTy == Ty);
140 return new MallocInst(AllocTy->getElementType(), Expr.Var, Name);
144 // ExpressionConvertibleToType - Return true if it is possible
145 bool llvm::ExpressionConvertibleToType(Value *V, const Type *Ty,
146 ValueTypeCache &CTMap, const TargetData &TD) {
147 // Expression type must be holdable in a register.
148 if (!Ty->isFirstClassType())
151 ValueTypeCache::iterator CTMI = CTMap.find(V);
152 if (CTMI != CTMap.end()) return CTMI->second == Ty;
154 // If it's a constant... all constants can be converted to a different
157 if (Constant *CPV = dyn_cast<Constant>(V))
161 if (V->getType() == Ty) return true; // Expression already correct type!
163 Instruction *I = dyn_cast<Instruction>(V);
164 if (I == 0) return false; // Otherwise, we can't convert!
166 switch (I->getOpcode()) {
167 case Instruction::Cast:
168 // We can convert the expr if the cast destination type is losslessly
169 // convertible to the requested type.
170 if (!Ty->isLosslesslyConvertibleTo(I->getType())) return false;
172 // We also do not allow conversion of a cast that casts from a ptr to array
173 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
175 if (const PointerType *SPT =
176 dyn_cast<PointerType>(I->getOperand(0)->getType()))
177 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
178 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
179 if (AT->getElementType() == DPT->getElementType())
183 case Instruction::Add:
184 case Instruction::Sub:
185 if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false;
186 if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD) ||
187 !ExpressionConvertibleToType(I->getOperand(1), Ty, CTMap, TD))
190 case Instruction::Shr:
191 if (!Ty->isInteger()) return false;
192 if (Ty->isSigned() != V->getType()->isSigned()) return false;
194 case Instruction::Shl:
195 if (!Ty->isInteger()) return false;
196 if (!ExpressionConvertibleToType(I->getOperand(0), Ty, CTMap, TD))
200 case Instruction::Load: {
201 LoadInst *LI = cast<LoadInst>(I);
202 if (!ExpressionConvertibleToType(LI->getPointerOperand(),
203 PointerType::get(Ty), CTMap, TD))
207 case Instruction::PHI: {
208 PHINode *PN = cast<PHINode>(I);
209 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
210 if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD))
215 case Instruction::Malloc:
216 if (!MallocConvertibleToType(cast<MallocInst>(I), Ty, CTMap, TD))
220 case Instruction::GetElementPtr: {
221 // GetElementPtr's are directly convertible to a pointer type if they have
222 // a number of zeros at the end. Because removing these values does not
223 // change the logical offset of the GEP, it is okay and fair to remove them.
224 // This can change this:
225 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
226 // %t2 = cast %List * * %t1 to %List *
228 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
230 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
231 const PointerType *PTy = dyn_cast<PointerType>(Ty);
232 if (!PTy) return false; // GEP must always return a pointer...
233 const Type *PVTy = PTy->getElementType();
235 // Check to see if there are zero elements that we can remove from the
236 // index array. If there are, check to see if removing them causes us to
237 // get to the right type...
239 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
240 const Type *BaseType = GEP->getPointerOperand()->getType();
241 const Type *ElTy = 0;
243 while (!Indices.empty() &&
244 Indices.back() == Constant::getNullValue(Indices.back()->getType())){
246 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
248 break; // Found a match!!
252 if (ElTy) break; // Found a number of zeros we can strip off!
254 // Otherwise, we can convert a GEP from one form to the other iff the
255 // current gep is of the form 'getelementptr sbyte*, long N
256 // and we could convert this to an appropriate GEP for the new type.
258 if (GEP->getNumOperands() == 2 &&
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 PTy->getElementType()->isSized() &&
287 TD.getTypeSize(PTy->getElementType()) ==
288 TD.getTypeSize(GEP->getType()->getElementType())) {
289 const PointerType *NewSrcTy = PointerType::get(PVTy);
290 if (!ExpressionConvertibleToType(I->getOperand(0), NewSrcTy, CTMap, TD))
295 return false; // No match, maybe next time.
298 case Instruction::Call: {
299 if (isa<Function>(I->getOperand(0)))
300 return false; // Don't even try to change direct calls.
302 // If this is a function pointer, we can convert the return type if we can
303 // convert the source function pointer.
305 const PointerType *PT = cast<PointerType>(I->getOperand(0)->getType());
306 const FunctionType *FT = cast<FunctionType>(PT->getElementType());
307 std::vector<const Type *> ArgTys(FT->param_begin(), FT->param_end());
308 const FunctionType *NewTy =
309 FunctionType::get(Ty, ArgTys, FT->isVarArg());
310 if (!ExpressionConvertibleToType(I->getOperand(0),
311 PointerType::get(NewTy), CTMap, TD))
319 // Expressions are only convertible if all of the users of the expression can
320 // have this value converted. This makes use of the map to avoid infinite
323 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
324 if (!OperandConvertibleToType(*It, I, Ty, CTMap, TD))
331 Value *llvm::ConvertExpressionToType(Value *V, const Type *Ty,
332 ValueMapCache &VMC, const TargetData &TD) {
333 if (V->getType() == Ty) return V; // Already where we need to be?
335 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
336 if (VMCI != VMC.ExprMap.end()) {
337 const Value *GV = VMCI->second;
338 const Type *GTy = VMCI->second->getType();
339 assert(VMCI->second->getType() == Ty);
341 if (Instruction *I = dyn_cast<Instruction>(V))
342 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
347 DEBUG(std::cerr << "CETT: " << (void*)V << " " << V);
349 Instruction *I = dyn_cast<Instruction>(V);
351 Constant *CPV = cast<Constant>(V);
352 // Constants are converted by constant folding the cast that is required.
353 // We assume here that all casts are implemented for constant prop.
354 Value *Result = ConstantExpr::getCast(CPV, Ty);
355 // Add the instruction to the expression map
356 //VMC.ExprMap[V] = Result;
361 BasicBlock *BB = I->getParent();
362 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
363 Instruction *Res; // Result of conversion
365 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
367 Constant *Dummy = Constant::getNullValue(Ty);
369 switch (I->getOpcode()) {
370 case Instruction::Cast:
371 assert(VMC.NewCasts.count(ValueHandle(VMC, I)) == 0);
372 Res = new CastInst(I->getOperand(0), Ty, Name);
373 VMC.NewCasts.insert(ValueHandle(VMC, Res));
376 case Instruction::Add:
377 case Instruction::Sub:
378 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
380 VMC.ExprMap[I] = Res; // Add node to expression eagerly
382 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD));
383 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC, TD));
386 case Instruction::Shl:
387 case Instruction::Shr:
388 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
389 I->getOperand(1), Name);
390 VMC.ExprMap[I] = Res;
391 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC, TD));
394 case Instruction::Load: {
395 LoadInst *LI = cast<LoadInst>(I);
397 Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
398 VMC.ExprMap[I] = Res;
399 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
400 PointerType::get(Ty), VMC, TD));
401 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
402 assert(Ty == Res->getType());
403 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
407 case Instruction::PHI: {
408 PHINode *OldPN = cast<PHINode>(I);
409 PHINode *NewPN = new PHINode(Ty, Name);
411 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
412 while (OldPN->getNumOperands()) {
413 BasicBlock *BB = OldPN->getIncomingBlock(0);
414 Value *OldVal = OldPN->getIncomingValue(0);
415 ValueHandle OldValHandle(VMC, OldVal);
416 OldPN->removeIncomingValue(BB, false);
417 Value *V = ConvertExpressionToType(OldVal, Ty, VMC, TD);
418 NewPN->addIncoming(V, BB);
424 case Instruction::Malloc: {
425 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC, TD);
429 case Instruction::GetElementPtr: {
430 // GetElementPtr's are directly convertible to a pointer type if they have
431 // a number of zeros at the end. Because removing these values does not
432 // change the logical offset of the GEP, it is okay and fair to remove them.
433 // This can change this:
434 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
435 // %t2 = cast %List * * %t1 to %List *
437 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
439 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
441 // Check to see if there are zero elements that we can remove from the
442 // index array. If there are, check to see if removing them causes us to
443 // get to the right type...
445 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
446 const Type *BaseType = GEP->getPointerOperand()->getType();
447 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
449 while (!Indices.empty() &&
450 Indices.back() == Constant::getNullValue(Indices.back()->getType())){
452 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
453 if (Indices.size() == 0)
454 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP CAST
456 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
461 if (Res == 0 && GEP->getNumOperands() == 2 &&
462 GEP->getType() == PointerType::get(Type::SByteTy)) {
464 // Otherwise, we can convert a GEP from one form to the other iff the
465 // current gep is of the form 'getelementptr sbyte*, unsigned N
466 // and we could convert this to an appropriate GEP for the new type.
468 const PointerType *NewSrcTy = PointerType::get(PVTy);
469 BasicBlock::iterator It = I;
471 // Check to see if 'N' is an expression that can be converted to
472 // the appropriate size... if so, allow it.
474 std::vector<Value*> Indices;
475 const Type *ElTy = ConvertibleToGEP(NewSrcTy, I->getOperand(1),
478 assert(ElTy == PVTy && "Internal error, setup wrong!");
479 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
481 VMC.ExprMap[I] = Res;
482 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
487 // Otherwise, it could be that we have something like this:
488 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
489 // and want to convert it into something like this:
490 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
493 const PointerType *NewSrcTy = PointerType::get(PVTy);
494 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
495 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
497 VMC.ExprMap[I] = Res;
498 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
503 assert(Res && "Didn't find match!");
507 case Instruction::Call: {
508 assert(!isa<Function>(I->getOperand(0)));
510 // If this is a function pointer, we can convert the return type if we can
511 // convert the source function pointer.
513 const PointerType *PT = cast<PointerType>(I->getOperand(0)->getType());
514 const FunctionType *FT = cast<FunctionType>(PT->getElementType());
515 std::vector<const Type *> ArgTys(FT->param_begin(), FT->param_end());
516 const FunctionType *NewTy =
517 FunctionType::get(Ty, ArgTys, FT->isVarArg());
518 const PointerType *NewPTy = PointerType::get(NewTy);
519 if (Ty == Type::VoidTy)
520 Name = ""; // Make sure not to name calls that now return void!
522 Res = new CallInst(Constant::getNullValue(NewPTy),
523 std::vector<Value*>(I->op_begin()+1, I->op_end()),
525 VMC.ExprMap[I] = Res;
526 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),NewPTy,VMC,TD));
530 assert(0 && "Expression convertible, but don't know how to convert?");
534 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
536 BB->getInstList().insert(I, Res);
538 // Add the instruction to the expression map
539 VMC.ExprMap[I] = Res;
542 unsigned NumUses = I->use_size();
543 for (unsigned It = 0; It < NumUses; ) {
544 unsigned OldSize = NumUses;
545 Value::use_iterator UI = I->use_begin();
546 std::advance(UI, It);
547 ConvertOperandToType(*UI, I, Res, VMC, TD);
548 NumUses = I->use_size();
549 if (NumUses == OldSize) ++It;
552 DEBUG(std::cerr << "ExpIn: " << (void*)I << " " << I
553 << "ExpOut: " << (void*)Res << " " << Res);
560 // ValueConvertibleToType - Return true if it is possible
561 bool llvm::ValueConvertibleToType(Value *V, const Type *Ty,
562 ValueTypeCache &ConvertedTypes,
563 const TargetData &TD) {
564 ValueTypeCache::iterator I = ConvertedTypes.find(V);
565 if (I != ConvertedTypes.end()) return I->second == Ty;
566 ConvertedTypes[V] = Ty;
568 // It is safe to convert the specified value to the specified type IFF all of
569 // the uses of the value can be converted to accept the new typed value.
571 if (V->getType() != Ty) {
572 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
573 if (!OperandConvertibleToType(*I, V, Ty, ConvertedTypes, TD))
584 // OperandConvertibleToType - Return true if it is possible to convert operand
585 // V of User (instruction) U to the specified type. This is true iff it is
586 // possible to change the specified instruction to accept this. CTMap is a map
587 // of converted types, so that circular definitions will see the future type of
588 // the expression, not the static current type.
590 static bool OperandConvertibleToType(User *U, Value *V, const Type *Ty,
591 ValueTypeCache &CTMap,
592 const TargetData &TD) {
593 // if (V->getType() == Ty) return true; // Operand already the right type?
595 // Expression type must be holdable in a register.
596 if (!Ty->isFirstClassType())
599 Instruction *I = dyn_cast<Instruction>(U);
600 if (I == 0) return false; // We can't convert!
602 switch (I->getOpcode()) {
603 case Instruction::Cast:
604 assert(I->getOperand(0) == V);
605 // We can convert the expr if the cast destination type is losslessly
606 // convertible to the requested type.
607 // Also, do not change a cast that is a noop cast. For all intents and
608 // purposes it should be eliminated.
609 if (!Ty->isLosslesslyConvertibleTo(I->getOperand(0)->getType()) ||
610 I->getType() == I->getOperand(0)->getType())
613 // Do not allow a 'cast ushort %V to uint' to have it's first operand be
614 // converted to a 'short' type. Doing so changes the way sign promotion
615 // happens, and breaks things. Only allow the cast to take place if the
616 // signedness doesn't change... or if the current cast is not a lossy
619 if (!I->getType()->isLosslesslyConvertibleTo(I->getOperand(0)->getType()) &&
620 I->getOperand(0)->getType()->isSigned() != Ty->isSigned())
623 // We also do not allow conversion of a cast that casts from a ptr to array
624 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
626 if (const PointerType *SPT =
627 dyn_cast<PointerType>(I->getOperand(0)->getType()))
628 if (const PointerType *DPT = dyn_cast<PointerType>(I->getType()))
629 if (const ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
630 if (AT->getElementType() == DPT->getElementType())
634 case Instruction::Add:
635 if (isa<PointerType>(Ty)) {
636 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
637 std::vector<Value*> Indices;
638 if (const Type *ETy = ConvertibleToGEP(Ty, IndexVal, Indices, TD)) {
639 const Type *RetTy = PointerType::get(ETy);
641 // Only successful if we can convert this type to the required type
642 if (ValueConvertibleToType(I, RetTy, CTMap, TD)) {
646 // We have to return failure here because ValueConvertibleToType could
647 // have polluted our map
652 case Instruction::Sub: {
653 if (!Ty->isInteger() && !Ty->isFloatingPoint()) return false;
655 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
656 return ValueConvertibleToType(I, Ty, CTMap, TD) &&
657 ExpressionConvertibleToType(OtherOp, Ty, CTMap, TD);
659 case Instruction::SetEQ:
660 case Instruction::SetNE: {
661 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
662 return ExpressionConvertibleToType(OtherOp, Ty, CTMap, TD);
664 case Instruction::Shr:
665 if (Ty->isSigned() != V->getType()->isSigned()) return false;
667 case Instruction::Shl:
668 if (I->getOperand(1) == V) return false; // Cannot change shift amount type
669 if (!Ty->isInteger()) return false;
670 return ValueConvertibleToType(I, Ty, CTMap, TD);
672 case Instruction::Free:
673 assert(I->getOperand(0) == V);
674 return isa<PointerType>(Ty); // Free can free any pointer type!
676 case Instruction::Load:
677 // Cannot convert the types of any subscripts...
678 if (I->getOperand(0) != V) return false;
680 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
681 LoadInst *LI = cast<LoadInst>(I);
683 const Type *LoadedTy = PT->getElementType();
685 // They could be loading the first element of a composite type...
686 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
687 unsigned Offset = 0; // No offset, get first leaf.
688 std::vector<Value*> Indices; // Discarded...
689 LoadedTy = getStructOffsetType(CT, Offset, Indices, TD, false);
690 assert(Offset == 0 && "Offset changed from zero???");
693 if (!LoadedTy->isFirstClassType())
696 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
699 return ValueConvertibleToType(LI, LoadedTy, CTMap, TD);
703 case Instruction::Store: {
704 StoreInst *SI = cast<StoreInst>(I);
706 if (V == I->getOperand(0)) {
707 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
708 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
709 // If so, check to see if it's Ty*, or, more importantly, if it is a
710 // pointer to a structure where the first element is a Ty... this code
711 // is necessary because we might be trying to change the source and
712 // destination type of the store (they might be related) and the dest
713 // pointer type might be a pointer to structure. Below we allow pointer
714 // to structures where the 0th element is compatible with the value,
715 // now we have to support the symmetrical part of this.
717 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
719 // Already a pointer to what we want? Trivially accept...
720 if (ElTy == Ty) return true;
722 // Tricky case now, if the destination is a pointer to structure,
723 // obviously the source is not allowed to be a structure (cannot copy
724 // a whole structure at a time), so the level raiser must be trying to
725 // store into the first field. Check for this and allow it now:
727 if (const StructType *SElTy = dyn_cast<StructType>(ElTy)) {
729 std::vector<Value*> Indices;
730 ElTy = getStructOffsetType(ElTy, Offset, Indices, TD, false);
731 assert(Offset == 0 && "Offset changed!");
732 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
733 return false; // Can only happen for {}*
735 if (ElTy == Ty) // Looks like the 0th element of structure is
736 return true; // compatible! Accept now!
738 // Otherwise we know that we can't work, so just stop trying now.
743 // Can convert the store if we can convert the pointer operand to match
744 // the new value type...
745 return ExpressionConvertibleToType(I->getOperand(1), PointerType::get(Ty),
747 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
748 const Type *ElTy = PT->getElementType();
749 assert(V == I->getOperand(1));
751 if (isa<StructType>(ElTy)) {
752 // We can change the destination pointer if we can store our first
753 // argument into the first element of the structure...
756 std::vector<Value*> Indices;
757 ElTy = getStructOffsetType(ElTy, Offset, Indices, TD, false);
758 assert(Offset == 0 && "Offset changed!");
759 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
760 return false; // Can only happen for {}*
763 // Must move the same amount of data...
764 if (!ElTy->isSized() ||
765 TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
768 // Can convert store if the incoming value is convertible and if the
769 // result will preserve semantics...
770 const Type *Op0Ty = I->getOperand(0)->getType();
771 if (!(Op0Ty->isIntegral() ^ ElTy->isIntegral()) &&
772 !(Op0Ty->isFloatingPoint() ^ ElTy->isFloatingPoint()))
773 return ExpressionConvertibleToType(I->getOperand(0), ElTy, CTMap, TD);
778 case Instruction::GetElementPtr:
779 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
781 // If we have a two operand form of getelementptr, this is really little
782 // more than a simple addition. As with addition, check to see if the
783 // getelementptr instruction can be changed to index into the new type.
785 if (I->getNumOperands() == 2) {
786 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
787 unsigned DataSize = TD.getTypeSize(OldElTy);
788 Value *Index = I->getOperand(1);
789 Instruction *TempScale = 0;
791 // If the old data element is not unit sized, we have to create a scale
792 // instruction so that ConvertibleToGEP will know the REAL amount we are
793 // indexing by. Note that this is never inserted into the instruction
794 // stream, so we have to delete it when we're done.
798 TempScale = BinaryOperator::create(Instruction::Mul, Index,
799 ConstantSInt::get(Type::LongTy,
804 // Check to see if the second argument is an expression that can
805 // be converted to the appropriate size... if so, allow it.
807 std::vector<Value*> Indices;
808 const Type *ElTy = ConvertibleToGEP(Ty, Index, Indices, TD);
809 delete TempScale; // Free our temporary multiply if we made it
811 if (ElTy == 0) return false; // Cannot make conversion...
812 return ValueConvertibleToType(I, PointerType::get(ElTy), CTMap, TD);
816 case Instruction::PHI: {
817 PHINode *PN = cast<PHINode>(I);
818 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
819 if (!ExpressionConvertibleToType(PN->getIncomingValue(i), Ty, CTMap, TD))
821 return ValueConvertibleToType(PN, Ty, CTMap, TD);
824 case Instruction::Call: {
825 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
826 assert (OI != I->op_end() && "Not using value!");
827 unsigned OpNum = OI - I->op_begin();
829 // Are we trying to change the function pointer value to a new type?
831 const PointerType *PTy = dyn_cast<PointerType>(Ty);
832 if (PTy == 0) return false; // Can't convert to a non-pointer type...
833 const FunctionType *FTy = dyn_cast<FunctionType>(PTy->getElementType());
834 if (FTy == 0) return false; // Can't convert to a non ptr to function...
836 // Do not allow converting to a call where all of the operands are ...'s
837 if (FTy->getNumParams() == 0 && FTy->isVarArg())
838 return false; // Do not permit this conversion!
840 // Perform sanity checks to make sure that new function type has the
841 // correct number of arguments...
843 unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr
845 // Cannot convert to a type that requires more fixed arguments than
846 // the call provides...
848 if (NumArgs < FTy->getNumParams()) return false;
850 // Unless this is a vararg function type, we cannot provide more arguments
851 // than are desired...
853 if (!FTy->isVarArg() && NumArgs > FTy->getNumParams())
856 // Okay, at this point, we know that the call and the function type match
857 // number of arguments. Now we see if we can convert the arguments
858 // themselves. Note that we do not require operands to be convertible,
859 // we can insert casts if they are convertible but not compatible. The
860 // reason for this is that we prefer to have resolved functions but casted
861 // arguments if possible.
863 for (unsigned i = 0, NA = FTy->getNumParams(); i < NA; ++i)
864 if (!FTy->getParamType(i)->isLosslesslyConvertibleTo(I->getOperand(i+1)->getType()))
865 return false; // Operands must have compatible types!
867 // Okay, at this point, we know that all of the arguments can be
868 // converted. We succeed if we can change the return type if
871 return ValueConvertibleToType(I, FTy->getReturnType(), CTMap, TD);
874 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
875 const FunctionType *FTy = cast<FunctionType>(MPtr->getElementType());
876 if (!FTy->isVarArg()) return false;
878 if ((OpNum-1) < FTy->getNumParams())
879 return false; // It's not in the varargs section...
881 // If we get this far, we know the value is in the varargs section of the
882 // function! We can convert if we don't reinterpret the value...
884 return Ty->isLosslesslyConvertibleTo(V->getType());
891 void llvm::ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC,
892 const TargetData &TD) {
893 ValueHandle VH(VMC, V);
895 unsigned NumUses = V->use_size();
896 for (unsigned It = 0; It < NumUses; ) {
897 unsigned OldSize = NumUses;
898 Value::use_iterator UI = V->use_begin();
899 std::advance(UI, It);
900 ConvertOperandToType(*UI, V, NewVal, VMC, TD);
901 NumUses = V->use_size();
902 if (NumUses == OldSize) ++It;
908 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
909 ValueMapCache &VMC, const TargetData &TD) {
910 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
912 if (VMC.OperandsMapped.count(U)) return;
913 VMC.OperandsMapped.insert(U);
915 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
916 if (VMCI != VMC.ExprMap.end())
920 Instruction *I = cast<Instruction>(U); // Only Instructions convertible
922 BasicBlock *BB = I->getParent();
923 assert(BB != 0 && "Instruction not embedded in basic block!");
924 std::string Name = I->getName();
926 Instruction *Res; // Result of conversion
928 //std::cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I
929 // << "BB Before: " << BB << endl;
931 // Prevent I from being removed...
932 ValueHandle IHandle(VMC, I);
934 const Type *NewTy = NewVal->getType();
935 Constant *Dummy = (NewTy != Type::VoidTy) ?
936 Constant::getNullValue(NewTy) : 0;
938 switch (I->getOpcode()) {
939 case Instruction::Cast:
940 if (VMC.NewCasts.count(ValueHandle(VMC, I))) {
941 // This cast has already had it's value converted, causing a new cast to
942 // be created. We don't want to create YET ANOTHER cast instruction
943 // representing the original one, so just modify the operand of this cast
944 // instruction, which we know is newly created.
945 I->setOperand(0, NewVal);
946 I->setName(Name); // give I its name back
950 Res = new CastInst(NewVal, I->getType(), Name);
954 case Instruction::Add:
955 if (isa<PointerType>(NewTy)) {
956 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
957 std::vector<Value*> Indices;
958 BasicBlock::iterator It = I;
960 if (const Type *ETy = ConvertibleToGEP(NewTy, IndexVal, Indices, TD,&It)){
961 // If successful, convert the add to a GEP
962 //const Type *RetTy = PointerType::get(ETy);
963 // First operand is actually the given pointer...
964 Res = new GetElementPtrInst(NewVal, Indices, Name);
965 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
966 "ConvertibleToGEP broken!");
972 case Instruction::Sub:
973 case Instruction::SetEQ:
974 case Instruction::SetNE: {
975 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
977 VMC.ExprMap[I] = Res; // Add node to expression eagerly
979 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
980 Value *OtherOp = I->getOperand(OtherIdx);
981 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC, TD);
983 Res->setOperand(OtherIdx, NewOther);
984 Res->setOperand(!OtherIdx, NewVal);
987 case Instruction::Shl:
988 case Instruction::Shr:
989 assert(I->getOperand(0) == OldVal);
990 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
991 I->getOperand(1), Name);
994 case Instruction::Free: // Free can free any pointer type!
995 assert(I->getOperand(0) == OldVal);
996 Res = new FreeInst(NewVal);
1000 case Instruction::Load: {
1001 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
1002 const Type *LoadedTy =
1003 cast<PointerType>(NewVal->getType())->getElementType();
1005 Value *Src = NewVal;
1007 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
1008 std::vector<Value*> Indices;
1010 Indices.push_back(ConstantSInt::get(Type::LongTy, 0));
1012 unsigned Offset = 0; // No offset, get first leaf.
1013 LoadedTy = getStructOffsetType(CT, Offset, Indices, TD, false);
1014 assert(LoadedTy->isFirstClassType());
1016 if (Indices.size() != 1) { // Do not generate load X, 0
1017 // Insert the GEP instruction before this load.
1018 Src = new GetElementPtrInst(Src, Indices, Name+".idx", I);
1022 Res = new LoadInst(Src, Name);
1023 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
1027 case Instruction::Store: {
1028 if (I->getOperand(0) == OldVal) { // Replace the source value
1029 // Check to see if operand #1 has already been converted...
1030 ValueMapCache::ExprMapTy::iterator VMCI =
1031 VMC.ExprMap.find(I->getOperand(1));
1032 if (VMCI != VMC.ExprMap.end()) {
1033 // Comments describing this stuff are in the OperandConvertibleToType
1034 // switch statement for Store...
1037 cast<PointerType>(VMCI->second->getType())->getElementType();
1039 Value *SrcPtr = VMCI->second;
1041 if (ElTy != NewTy) {
1042 // We check that this is a struct in the initial scan...
1043 const StructType *SElTy = cast<StructType>(ElTy);
1045 std::vector<Value*> Indices;
1047 Indices.push_back(Constant::getNullValue(Type::LongTy));
1049 unsigned Offset = 0;
1050 const Type *Ty = getStructOffsetType(ElTy, Offset, Indices, TD,false);
1051 assert(Offset == 0 && "Offset changed!");
1052 assert(NewTy == Ty && "Did not convert to correct type!");
1054 // Insert the GEP instruction before this store.
1055 SrcPtr = new GetElementPtrInst(SrcPtr, Indices,
1056 SrcPtr->getName()+".idx", I);
1058 Res = new StoreInst(NewVal, SrcPtr);
1060 VMC.ExprMap[I] = Res;
1062 // Otherwise, we haven't converted Operand #1 over yet...
1063 const PointerType *NewPT = PointerType::get(NewTy);
1064 Res = new StoreInst(NewVal, Constant::getNullValue(NewPT));
1065 VMC.ExprMap[I] = Res;
1066 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1),
1069 } else { // Replace the source pointer
1070 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1072 Value *SrcPtr = NewVal;
1074 if (isa<StructType>(ValTy)) {
1075 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,
1111 ConstantSInt::get(Type::LongTy, DataSize),
1115 // Perform the conversion now...
1117 std::vector<Value*> Indices;
1118 const Type *ElTy = ConvertibleToGEP(NewVal->getType(),Index,Indices,TD,&It);
1119 assert(ElTy != 0 && "GEP Conversion Failure!");
1120 Res = new GetElementPtrInst(NewVal, Indices, Name);
1121 assert(Res->getType() == PointerType::get(ElTy) &&
1122 "ConvertibleToGet failed!");
1125 if (I->getType() == PointerType::get(Type::SByteTy)) {
1126 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1127 // anything that is a pointer type...
1129 BasicBlock::iterator It = I;
1131 // Check to see if the second argument is an expression that can
1132 // be converted to the appropriate size... if so, allow it.
1134 std::vector<Value*> Indices;
1135 const Type *ElTy = ConvertibleToGEP(NewVal->getType(), I->getOperand(1),
1137 assert(ElTy != 0 && "GEP Conversion Failure!");
1139 Res = new GetElementPtrInst(NewVal, Indices, Name);
1141 // Convert a getelementptr ulong * %reg123, uint %N
1142 // to getelementptr long * %reg123, uint %N
1143 // ... where the type must simply stay the same size...
1145 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
1146 std::vector<Value*> Indices(GEP->idx_begin(), GEP->idx_end());
1147 Res = new GetElementPtrInst(NewVal, Indices, Name);
1152 case Instruction::PHI: {
1153 PHINode *OldPN = cast<PHINode>(I);
1154 PHINode *NewPN = new PHINode(NewTy, Name);
1155 VMC.ExprMap[I] = NewPN;
1157 while (OldPN->getNumOperands()) {
1158 BasicBlock *BB = OldPN->getIncomingBlock(0);
1159 Value *OldVal = OldPN->getIncomingValue(0);
1160 OldPN->removeIncomingValue(BB, false);
1161 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC, TD);
1162 NewPN->addIncoming(V, BB);
1168 case Instruction::Call: {
1169 Value *Meth = I->getOperand(0);
1170 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1172 if (Meth == OldVal) { // Changing the function pointer?
1173 const PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1174 const FunctionType *NewTy = cast<FunctionType>(NewPTy->getElementType());
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 != NewTy->getNumParams(); ++i)
1191 if (Params[i]->getType() != NewTy->getParamType(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], NewTy->getParamType(i),
1197 Params[i]->getName(), It);
1199 Meth = NewVal; // Update call destination to new value
1201 } else { // Changing an argument, must be in vararg area
1202 std::vector<Value*>::iterator OI =
1203 find(Params.begin(), Params.end(), OldVal);
1204 assert (OI != Params.end() && "Not using value!");
1209 Res = new CallInst(Meth, Params, Name);
1213 assert(0 && "Expression convertible, but don't know how to convert?");
1217 // If the instruction was newly created, insert it into the instruction
1220 BasicBlock::iterator It = I;
1221 assert(It != BB->end() && "Instruction not in own basic block??");
1222 BB->getInstList().insert(It, Res); // Keep It pointing to old instruction
1224 DEBUG(std::cerr << "COT CREATED: " << (void*)Res << " " << Res
1225 << "In: " << (void*)I << " " << I << "Out: " << (void*)Res
1228 // Add the instruction to the expression map
1229 VMC.ExprMap[I] = Res;
1231 if (I->getType() != Res->getType())
1232 ConvertValueToNewType(I, Res, VMC, TD);
1234 bool FromStart = true;
1235 Value::use_iterator UI;
1237 if (FromStart) UI = I->use_begin();
1238 if (UI == I->use_end()) break;
1240 if (isa<ValueHandle>(*UI)) {
1245 if (!FromStart) --UI;
1246 U->replaceUsesOfWith(I, Res);
1247 if (!FromStart) ++UI;
1254 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1255 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1256 //DEBUG(std::cerr << "VH AQUIRING: " << (void*)V << " " << V);
1257 Operands.push_back(Use(V, this));
1260 ValueHandle::ValueHandle(const ValueHandle &VH)
1261 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VH.Cache) {
1262 //DEBUG(std::cerr << "VH AQUIRING: " << (void*)V << " " << V);
1263 Operands.push_back(Use((Value*)VH.getOperand(0), this));
1266 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1267 if (!I || !I->use_empty()) return;
1269 assert(I->getParent() && "Inst not in basic block!");
1271 //DEBUG(std::cerr << "VH DELETING: " << (void*)I << " " << I);
1273 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1275 if (Instruction *U = dyn_cast<Instruction>(OI)) {
1277 RecursiveDelete(Cache, U);
1280 I->getParent()->getInstList().remove(I);
1282 Cache.OperandsMapped.erase(I);
1283 Cache.ExprMap.erase(I);
1287 ValueHandle::~ValueHandle() {
1288 if (Operands[0]->hasOneUse()) {
1289 Value *V = Operands[0];
1290 Operands[0] = 0; // Drop use!
1292 // Now we just need to remove the old instruction so we don't get infinite
1293 // loops. Note that we cannot use DCE because DCE won't remove a store
1294 // instruction, for example.
1296 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1298 //DEBUG(std::cerr << "VH RELEASING: " << (void*)Operands[0].get() << " "
1299 // << Operands[0]->use_size() << " " << Operands[0]);