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/Method.h"
11 #include "llvm/iOther.h"
12 #include "llvm/iPHINode.h"
13 #include "llvm/iMemory.h"
14 #include "llvm/ConstantVals.h"
15 #include "llvm/Transforms/Scalar/ConstantHandling.h"
16 #include "llvm/Transforms/Scalar/DCE.h"
17 #include "llvm/Analysis/Expressions.h"
18 #include "Support/STLExtras.h"
24 #include "llvm/Assembly/Writer.h"
26 //#define DEBUG_EXPR_CONVERT 1
28 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
29 ValueTypeCache &ConvertedTypes);
31 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
34 // AllIndicesZero - Return true if all of the indices of the specified memory
35 // access instruction are zero, indicating an effectively nil offset to the
38 static bool AllIndicesZero(const MemAccessInst *MAI) {
39 for (User::const_op_iterator S = MAI->idx_begin(), E = MAI->idx_end();
41 if (!isa<Constant>(*S) || !cast<Constant>(*S)->isNullValue())
47 // Peephole Malloc instructions: we take a look at the use chain of the
48 // malloc instruction, and try to find out if the following conditions hold:
49 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
50 // 2. The only users of the malloc are cast & add instructions
51 // 3. Of the cast instructions, there is only one destination pointer type
52 // [RTy] where the size of the pointed to object is equal to the number
53 // of bytes allocated.
55 // If these conditions hold, we convert the malloc to allocate an [RTy]
56 // element. TODO: This comment is out of date WRT arrays
58 static bool MallocConvertableToType(MallocInst *MI, const Type *Ty,
59 ValueTypeCache &CTMap) {
60 if (!MI->isArrayAllocation() || // No array allocation?
61 !isa<PointerType>(Ty)) return false; // Malloc always returns pointers
63 // Deal with the type to allocate, not the pointer type...
64 Ty = cast<PointerType>(Ty)->getElementType();
65 if (!Ty->isSized()) return false; // Can only alloc something with a size
67 // Analyze the number of bytes allocated...
68 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
70 // Get information about the base datatype being allocated, before & after
71 unsigned ReqTypeSize = TD.getTypeSize(Ty);
72 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
74 // Must have a scale or offset to analyze it...
75 if (!Expr.Offset && !Expr.Scale) return false;
77 // Get the offset and scale of the allocation...
78 int OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
79 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
80 if (ScaleVal < 0 || OffsetVal < 0) {
81 cerr << "malloc of a negative number???\n";
85 // The old type might not be of unit size, take old size into consideration
87 unsigned Offset = (unsigned)OffsetVal * OldTypeSize;
88 unsigned Scale = (unsigned)ScaleVal * OldTypeSize;
90 // In order to be successful, both the scale and the offset must be a multiple
91 // of the requested data type's size.
93 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
94 Scale/ReqTypeSize*ReqTypeSize != Scale)
95 return false; // Nope.
100 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
101 const std::string &Name,
103 BasicBlock *BB = MI->getParent();
104 BasicBlock::iterator It = BB->end();
106 // Analyze the number of bytes allocated...
107 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
109 const PointerType *AllocTy = cast<PointerType>(Ty);
110 const Type *ElType = AllocTy->getElementType();
112 unsigned DataSize = TD.getTypeSize(ElType);
113 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
115 // Get the offset and scale coefficients that we are allocating...
116 int OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
117 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
119 // The old type might not be of unit size, take old size into consideration
121 unsigned Offset = (unsigned)OffsetVal * OldTypeSize / DataSize;
122 unsigned Scale = (unsigned)ScaleVal * OldTypeSize / DataSize;
124 // Locate the malloc instruction, because we may be inserting instructions
125 It = find(BB->getInstList().begin(), BB->getInstList().end(), MI);
127 // If we have a scale, apply it first...
129 // Expr.Var is not neccesarily unsigned right now, insert a cast now.
130 if (Expr.Var->getType() != Type::UIntTy) {
131 Instruction *CI = new CastInst(Expr.Var, Type::UIntTy);
132 if (Expr.Var->hasName()) CI->setName(Expr.Var->getName()+"-uint");
133 It = BB->getInstList().insert(It, CI)+1;
139 BinaryOperator::create(Instruction::Mul, Expr.Var,
140 ConstantUInt::get(Type::UIntTy, Scale));
141 if (Expr.Var->hasName()) ScI->setName(Expr.Var->getName()+"-scl");
142 It = BB->getInstList().insert(It, ScI)+1;
147 // If we are not scaling anything, just make the offset be the "var"...
148 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
149 Offset = 0; Scale = 1;
152 // If we have an offset now, add it in...
154 assert(Expr.Var && "Var must be nonnull by now!");
157 BinaryOperator::create(Instruction::Add, Expr.Var,
158 ConstantUInt::get(Type::UIntTy, Offset));
159 if (Expr.Var->hasName()) AddI->setName(Expr.Var->getName()+"-off");
160 It = BB->getInstList().insert(It, AddI)+1;
164 Instruction *NewI = new MallocInst(AllocTy, Expr.Var, Name);
166 assert(AllocTy == Ty);
171 // ExpressionConvertableToType - Return true if it is possible
172 bool ExpressionConvertableToType(Value *V, const Type *Ty,
173 ValueTypeCache &CTMap) {
174 if (V->getType() == Ty) return true; // Expression already correct type!
176 // Expression type must be holdable in a register.
177 if (!Ty->isFirstClassType())
180 ValueTypeCache::iterator CTMI = CTMap.find(V);
181 if (CTMI != CTMap.end()) return CTMI->second == Ty;
185 Instruction *I = dyn_cast<Instruction>(V);
187 // It's not an instruction, check to see if it's a constant... all constants
188 // can be converted to an equivalent value (except pointers, they can't be
189 // const prop'd in general). We just ask the constant propogator to see if
190 // it can convert the value...
192 if (Constant *CPV = dyn_cast<Constant>(V))
193 if (ConstantFoldCastInstruction(CPV, Ty))
194 return true; // Don't worry about deallocating, it's a constant.
196 return false; // Otherwise, we can't convert!
199 switch (I->getOpcode()) {
200 case Instruction::Cast:
201 // We can convert the expr if the cast destination type is losslessly
202 // convertable to the requested type.
203 if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
205 // We also do not allow conversion of a cast that casts from a ptr to array
206 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
208 if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
209 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
210 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
211 if (AT->getElementType() == DPT->getElementType())
216 case Instruction::Add:
217 case Instruction::Sub:
218 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
219 !ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
222 case Instruction::Shr:
223 if (Ty->isSigned() != V->getType()->isSigned()) return false;
225 case Instruction::Shl:
226 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
230 case Instruction::Load: {
231 LoadInst *LI = cast<LoadInst>(I);
232 if (LI->hasIndices() && !AllIndicesZero(LI)) {
233 // We can't convert a load expression if it has indices... unless they are
238 if (!ExpressionConvertableToType(LI->getPointerOperand(),
239 PointerType::get(Ty), CTMap))
243 case Instruction::PHINode: {
244 PHINode *PN = cast<PHINode>(I);
245 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
246 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
251 case Instruction::Malloc:
252 if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
257 case Instruction::GetElementPtr: {
258 // GetElementPtr's are directly convertable to a pointer type if they have
259 // a number of zeros at the end. Because removing these values does not
260 // change the logical offset of the GEP, it is okay and fair to remove them.
261 // This can change this:
262 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
263 // %t2 = cast %List * * %t1 to %List *
265 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
267 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
268 const PointerType *PTy = dyn_cast<PointerType>(Ty);
269 if (!PTy) return false; // GEP must always return a pointer...
270 const Type *PVTy = PTy->getElementType();
272 // Check to see if there are zero elements that we can remove from the
273 // index array. If there are, check to see if removing them causes us to
274 // get to the right type...
276 std::vector<Value*> Indices = GEP->copyIndices();
277 const Type *BaseType = GEP->getPointerOperand()->getType();
278 const Type *ElTy = 0;
280 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
281 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
283 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
285 break; // Found a match!!
289 if (ElTy) break; // Found a number of zeros we can strip off!
291 // Otherwise, we can convert a GEP from one form to the other iff the
292 // current gep is of the form 'getelementptr sbyte*, unsigned N
293 // and we could convert this to an appropriate GEP for the new type.
295 if (GEP->getNumOperands() == 2 &&
296 GEP->getOperand(1)->getType() == Type::UIntTy &&
297 GEP->getType() == PointerType::get(Type::SByteTy)) {
299 // Do not Check to see if our incoming pointer can be converted
300 // to be a ptr to an array of the right type... because in more cases than
301 // not, it is simply not analyzable because of pointer/array
302 // discrepencies. To fix this, we will insert a cast before the GEP.
305 // Check to see if 'N' is an expression that can be converted to
306 // the appropriate size... if so, allow it.
308 std::vector<Value*> Indices;
309 const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
311 assert(ElTy == PVTy && "Internal error, setup wrong!");
312 if (!ExpressionConvertableToType(I->getOperand(0),
313 PointerType::get(ElTy), CTMap))
314 return false; // Can't continue, ExConToTy might have polluted set!
319 // Otherwise, it could be that we have something like this:
320 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
321 // and want to convert it into something like this:
322 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
324 if (GEP->getNumOperands() == 2 &&
325 GEP->getOperand(1)->getType() == Type::UIntTy &&
326 TD.getTypeSize(PTy->getElementType()) ==
327 TD.getTypeSize(GEP->getType()->getElementType())) {
328 const PointerType *NewSrcTy = PointerType::get(PVTy);
329 if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
334 return false; // No match, maybe next time.
342 // Expressions are only convertable if all of the users of the expression can
343 // have this value converted. This makes use of the map to avoid infinite
346 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
347 if (!OperandConvertableToType(*It, I, Ty, CTMap))
354 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
355 if (V->getType() == Ty) return V; // Already where we need to be?
357 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
358 if (VMCI != VMC.ExprMap.end()) {
359 assert(VMCI->second->getType() == Ty);
361 if (Instruction *I = dyn_cast<Instruction>(V))
362 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
367 #ifdef DEBUG_EXPR_CONVERT
368 cerr << "CETT: " << (void*)V << " " << V;
371 Instruction *I = dyn_cast<Instruction>(V);
373 if (Constant *CPV = cast<Constant>(V)) {
374 // Constants are converted by constant folding the cast that is required.
375 // We assume here that all casts are implemented for constant prop.
376 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
377 assert(Result && "ConstantFoldCastInstruction Failed!!!");
378 assert(Result->getType() == Ty && "Const prop of cast failed!");
380 // Add the instruction to the expression map
381 VMC.ExprMap[V] = Result;
386 BasicBlock *BB = I->getParent();
387 BasicBlock::InstListType &BIL = BB->getInstList();
388 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
389 Instruction *Res; // Result of conversion
391 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
393 Constant *Dummy = Constant::getNullConstant(Ty);
395 switch (I->getOpcode()) {
396 case Instruction::Cast:
397 Res = new CastInst(I->getOperand(0), Ty, Name);
400 case Instruction::Add:
401 case Instruction::Sub:
402 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
404 VMC.ExprMap[I] = Res; // Add node to expression eagerly
406 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
407 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
410 case Instruction::Shl:
411 case Instruction::Shr:
412 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
413 I->getOperand(1), Name);
414 VMC.ExprMap[I] = Res;
415 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
418 case Instruction::Load: {
419 LoadInst *LI = cast<LoadInst>(I);
420 assert(!LI->hasIndices() || AllIndicesZero(LI));
422 Res = new LoadInst(Constant::getNullConstant(PointerType::get(Ty)), Name);
423 VMC.ExprMap[I] = Res;
424 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
425 PointerType::get(Ty), VMC));
426 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
427 assert(Ty == Res->getType());
428 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
432 case Instruction::PHINode: {
433 PHINode *OldPN = cast<PHINode>(I);
434 PHINode *NewPN = new PHINode(Ty, Name);
436 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
437 while (OldPN->getNumOperands()) {
438 BasicBlock *BB = OldPN->getIncomingBlock(0);
439 Value *OldVal = OldPN->getIncomingValue(0);
440 ValueHandle OldValHandle(VMC, OldVal);
441 OldPN->removeIncomingValue(BB);
442 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
443 NewPN->addIncoming(V, BB);
449 case Instruction::Malloc: {
450 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
454 case Instruction::GetElementPtr: {
455 // GetElementPtr's are directly convertable to a pointer type if they have
456 // a number of zeros at the end. Because removing these values does not
457 // change the logical offset of the GEP, it is okay and fair to remove them.
458 // This can change this:
459 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
460 // %t2 = cast %List * * %t1 to %List *
462 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
464 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
466 // Check to see if there are zero elements that we can remove from the
467 // index array. If there are, check to see if removing them causes us to
468 // get to the right type...
470 std::vector<Value*> Indices = GEP->copyIndices();
471 const Type *BaseType = GEP->getPointerOperand()->getType();
472 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
474 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
475 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
477 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
478 if (Indices.size() == 0) {
479 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
481 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
487 if (Res == 0 && GEP->getNumOperands() == 2 &&
488 GEP->getOperand(1)->getType() == Type::UIntTy &&
489 GEP->getType() == PointerType::get(Type::SByteTy)) {
491 // Otherwise, we can convert a GEP from one form to the other iff the
492 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
493 // and we could convert this to an appropriate GEP for the new type.
495 const PointerType *NewSrcTy = PointerType::get(PVTy);
496 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
498 // Check to see if 'N' is an expression that can be converted to
499 // the appropriate size... if so, allow it.
501 std::vector<Value*> Indices;
502 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
505 assert(ElTy == PVTy && "Internal error, setup wrong!");
506 Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
508 VMC.ExprMap[I] = Res;
509 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
514 // Otherwise, it could be that we have something like this:
515 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
516 // and want to convert it into something like this:
517 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
520 const PointerType *NewSrcTy = PointerType::get(PVTy);
521 Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
522 GEP->copyIndices(), Name);
523 VMC.ExprMap[I] = Res;
524 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
529 assert(Res && "Didn't find match!");
530 break; // No match, maybe next time.
534 assert(0 && "Expression convertable, but don't know how to convert?");
538 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
540 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
541 assert(It != BIL.end() && "Instruction not in own basic block??");
544 // Add the instruction to the expression map
545 VMC.ExprMap[I] = Res;
547 // Expressions are only convertable if all of the users of the expression can
548 // have this value converted. This makes use of the map to avoid infinite
551 unsigned NumUses = I->use_size();
552 for (unsigned It = 0; It < NumUses; ) {
553 unsigned OldSize = NumUses;
554 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
555 NumUses = I->use_size();
556 if (NumUses == OldSize) ++It;
559 #ifdef DEBUG_EXPR_CONVERT
560 cerr << "ExpIn: " << (void*)I << " " << I
561 << "ExpOut: " << (void*)Res << " " << Res;
564 if (I->use_empty()) {
565 #ifdef DEBUG_EXPR_CONVERT
566 cerr << "EXPR DELETING: " << (void*)I << " " << I;
569 VMC.OperandsMapped.erase(I);
570 VMC.ExprMap.erase(I);
579 // ValueConvertableToType - Return true if it is possible
580 bool ValueConvertableToType(Value *V, const Type *Ty,
581 ValueTypeCache &ConvertedTypes) {
582 ValueTypeCache::iterator I = ConvertedTypes.find(V);
583 if (I != ConvertedTypes.end()) return I->second == Ty;
584 ConvertedTypes[V] = Ty;
586 // It is safe to convert the specified value to the specified type IFF all of
587 // the uses of the value can be converted to accept the new typed value.
589 if (V->getType() != Ty) {
590 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
591 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
602 // OperandConvertableToType - Return true if it is possible to convert operand
603 // V of User (instruction) U to the specified type. This is true iff it is
604 // possible to change the specified instruction to accept this. CTMap is a map
605 // of converted types, so that circular definitions will see the future type of
606 // the expression, not the static current type.
608 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
609 ValueTypeCache &CTMap) {
610 // if (V->getType() == Ty) return true; // Operand already the right type?
612 // Expression type must be holdable in a register.
613 if (!Ty->isFirstClassType())
616 Instruction *I = dyn_cast<Instruction>(U);
617 if (I == 0) return false; // We can't convert!
619 switch (I->getOpcode()) {
620 case Instruction::Cast:
621 assert(I->getOperand(0) == V);
622 // We can convert the expr if the cast destination type is losslessly
623 // convertable to the requested type.
624 // Also, do not change a cast that is a noop cast. For all intents and
625 // purposes it should be eliminated.
626 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
627 I->getType() == I->getOperand(0)->getType())
632 // We also do not allow conversion of a cast that casts from a ptr to array
633 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
635 if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
636 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
637 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
638 if (AT->getElementType() == DPT->getElementType())
643 case Instruction::Add:
644 if (isa<PointerType>(Ty)) {
645 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
646 std::vector<Value*> Indices;
647 if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
648 const Type *RetTy = PointerType::get(ETy);
650 // Only successful if we can convert this type to the required type
651 if (ValueConvertableToType(I, RetTy, CTMap)) {
655 // We have to return failure here because ValueConvertableToType could
656 // have polluted our map
661 case Instruction::Sub: {
662 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
663 return ValueConvertableToType(I, Ty, CTMap) &&
664 ExpressionConvertableToType(OtherOp, Ty, CTMap);
666 case Instruction::SetEQ:
667 case Instruction::SetNE: {
668 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
669 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
671 case Instruction::Shr:
672 if (Ty->isSigned() != V->getType()->isSigned()) return false;
674 case Instruction::Shl:
675 assert(I->getOperand(0) == V);
676 return ValueConvertableToType(I, Ty, CTMap);
678 case Instruction::Free:
679 assert(I->getOperand(0) == V);
680 return isa<PointerType>(Ty); // Free can free any pointer type!
682 case Instruction::Load:
683 // Cannot convert the types of any subscripts...
684 if (I->getOperand(0) != V) return false;
686 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
687 LoadInst *LI = cast<LoadInst>(I);
689 if (LI->hasIndices() && !AllIndicesZero(LI))
692 const Type *LoadedTy = PT->getElementType();
694 // They could be loading the first element of a composite type...
695 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
696 unsigned Offset = 0; // No offset, get first leaf.
697 std::vector<Value*> Indices; // Discarded...
698 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
699 assert(Offset == 0 && "Offset changed from zero???");
702 if (!LoadedTy->isFirstClassType())
705 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
708 return ValueConvertableToType(LI, LoadedTy, CTMap);
712 case Instruction::Store: {
713 StoreInst *SI = cast<StoreInst>(I);
714 if (SI->hasIndices()) return false;
716 if (V == I->getOperand(0)) {
717 // Can convert the store if we can convert the pointer operand to match
718 // the new value type...
719 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
721 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
722 const Type *ElTy = PT->getElementType();
723 assert(V == I->getOperand(1));
725 // Must move the same amount of data...
726 if (TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
729 // Can convert store if the incoming value is convertable...
730 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
735 case Instruction::GetElementPtr:
736 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
738 // If we have a two operand form of getelementptr, this is really little
739 // more than a simple addition. As with addition, check to see if the
740 // getelementptr instruction can be changed to index into the new type.
742 if (I->getNumOperands() == 2) {
743 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
744 unsigned DataSize = TD.getTypeSize(OldElTy);
745 Value *Index = I->getOperand(1);
746 Instruction *TempScale = 0;
748 // If the old data element is not unit sized, we have to create a scale
749 // instruction so that ConvertableToGEP will know the REAL amount we are
750 // indexing by. Note that this is never inserted into the instruction
751 // stream, so we have to delete it when we're done.
754 TempScale = BinaryOperator::create(Instruction::Mul, Index,
755 ConstantUInt::get(Type::UIntTy,
760 // Check to see if the second argument is an expression that can
761 // be converted to the appropriate size... if so, allow it.
763 std::vector<Value*> Indices;
764 const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
765 delete TempScale; // Free our temporary multiply if we made it
767 if (ElTy == 0) return false; // Cannot make conversion...
768 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
772 case Instruction::PHINode: {
773 PHINode *PN = cast<PHINode>(I);
774 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
775 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
777 return ValueConvertableToType(PN, Ty, CTMap);
780 case Instruction::Call: {
781 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
782 assert (OI != I->op_end() && "Not using value!");
783 unsigned OpNum = OI - I->op_begin();
785 // Are we trying to change the method pointer value to a new type?
787 PointerType *PTy = dyn_cast<PointerType>(Ty);
788 if (PTy == 0) return false; // Can't convert to a non-pointer type...
789 MethodType *MTy = dyn_cast_or_null<MethodType>(PTy->getElementType());
790 if (MTy == 0) return false; // Can't convert to a non ptr to method...
792 // Perform sanity checks to make sure that new method type has the
793 // correct number of arguments...
795 unsigned NumArgs = I->getNumOperands()-1; // Don't include method ptr
797 // Cannot convert to a type that requires more fixed arguments than
798 // the call provides...
800 if (NumArgs < MTy->getParamTypes().size()) return false;
802 // Unless this is a vararg method type, we cannot provide more arguments
803 // than are desired...
805 if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
808 // Okay, at this point, we know that the call and the method type match
809 // number of arguments. Now we see if we can convert the arguments
812 const MethodType::ParamTypes &PTs = MTy->getParamTypes();
813 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
814 if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
815 return false; // Operands must have compatible types!
817 // Okay, at this point, we know that all of the arguments can be
818 // converted. We succeed if we can change the return type if
821 return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
824 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
825 const MethodType *MTy = cast<MethodType>(MPtr->getElementType());
826 if (!MTy->isVarArg()) return false;
828 if ((OpNum-1) < MTy->getParamTypes().size())
829 return false; // It's not in the varargs section...
831 // If we get this far, we know the value is in the varargs section of the
832 // method! We can convert if we don't reinterpret the value...
834 return Ty->isLosslesslyConvertableTo(V->getType());
841 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
842 ValueHandle VH(VMC, V);
844 unsigned NumUses = V->use_size();
845 for (unsigned It = 0; It < NumUses; ) {
846 unsigned OldSize = NumUses;
847 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
848 NumUses = V->use_size();
849 if (NumUses == OldSize) ++It;
855 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
856 ValueMapCache &VMC) {
857 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
859 if (VMC.OperandsMapped.count(U)) return;
860 VMC.OperandsMapped.insert(U);
862 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
863 if (VMCI != VMC.ExprMap.end())
867 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
869 BasicBlock *BB = I->getParent();
870 BasicBlock::InstListType &BIL = BB->getInstList();
871 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
872 Instruction *Res; // Result of conversion
874 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
876 // Prevent I from being removed...
877 ValueHandle IHandle(VMC, I);
879 const Type *NewTy = NewVal->getType();
880 Constant *Dummy = (NewTy != Type::VoidTy) ?
881 Constant::getNullConstant(NewTy) : 0;
883 switch (I->getOpcode()) {
884 case Instruction::Cast:
885 assert(I->getOperand(0) == OldVal);
886 Res = new CastInst(NewVal, I->getType(), Name);
889 case Instruction::Add:
890 if (isa<PointerType>(NewTy)) {
891 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
892 std::vector<Value*> Indices;
893 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
895 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
896 // If successful, convert the add to a GEP
897 //const Type *RetTy = PointerType::get(ETy);
898 // First operand is actually the given pointer...
899 Res = new GetElementPtrInst(NewVal, Indices, Name);
900 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
901 "ConvertableToGEP broken!");
907 case Instruction::Sub:
908 case Instruction::SetEQ:
909 case Instruction::SetNE: {
910 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
912 VMC.ExprMap[I] = Res; // Add node to expression eagerly
914 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
915 Value *OtherOp = I->getOperand(OtherIdx);
916 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
918 Res->setOperand(OtherIdx, NewOther);
919 Res->setOperand(!OtherIdx, NewVal);
922 case Instruction::Shl:
923 case Instruction::Shr:
924 assert(I->getOperand(0) == OldVal);
925 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
926 I->getOperand(1), Name);
929 case Instruction::Free: // Free can free any pointer type!
930 assert(I->getOperand(0) == OldVal);
931 Res = new FreeInst(NewVal);
935 case Instruction::Load: {
936 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
937 const Type *LoadedTy =
938 cast<PointerType>(NewVal->getType())->getElementType();
940 std::vector<Value*> Indices;
941 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
943 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
944 unsigned Offset = 0; // No offset, get first leaf.
945 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
947 assert(LoadedTy->isFirstClassType());
949 Res = new LoadInst(NewVal, Indices, Name);
950 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
954 case Instruction::Store: {
955 if (I->getOperand(0) == OldVal) { // Replace the source value
956 const PointerType *NewPT = PointerType::get(NewTy);
957 Res = new StoreInst(NewVal, Constant::getNullConstant(NewPT));
958 VMC.ExprMap[I] = Res;
959 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC));
960 } else { // Replace the source pointer
961 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
962 std::vector<Value*> Indices;
964 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
965 while (ArrayType *AT = dyn_cast<ArrayType>(ValTy)) {
966 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
967 ValTy = AT->getElementType();
970 Res = new StoreInst(Constant::getNullConstant(ValTy), NewVal, Indices);
971 VMC.ExprMap[I] = Res;
972 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
978 case Instruction::GetElementPtr: {
979 // Convert a one index getelementptr into just about anything that is
982 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
983 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
984 unsigned DataSize = TD.getTypeSize(OldElTy);
985 Value *Index = I->getOperand(1);
988 // Insert a multiply of the old element type is not a unit size...
989 Index = BinaryOperator::create(Instruction::Mul, Index,
990 ConstantUInt::get(Type::UIntTy, DataSize));
991 It = BIL.insert(It, cast<Instruction>(Index))+1;
994 // Perform the conversion now...
996 std::vector<Value*> Indices;
997 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
998 assert(ElTy != 0 && "GEP Conversion Failure!");
999 Res = new GetElementPtrInst(NewVal, Indices, Name);
1000 assert(Res->getType() == PointerType::get(ElTy) &&
1001 "ConvertableToGet failed!");
1004 if (I->getType() == PointerType::get(Type::SByteTy)) {
1005 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1006 // anything that is a pointer type...
1008 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1010 // Check to see if the second argument is an expression that can
1011 // be converted to the appropriate size... if so, allow it.
1013 std::vector<Value*> Indices;
1014 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
1016 assert(ElTy != 0 && "GEP Conversion Failure!");
1018 Res = new GetElementPtrInst(NewVal, Indices, Name);
1020 // Convert a getelementptr ulong * %reg123, uint %N
1021 // to getelementptr long * %reg123, uint %N
1022 // ... where the type must simply stay the same size...
1024 Res = new GetElementPtrInst(NewVal,
1025 cast<GetElementPtrInst>(I)->copyIndices(),
1031 case Instruction::PHINode: {
1032 PHINode *OldPN = cast<PHINode>(I);
1033 PHINode *NewPN = new PHINode(NewTy, Name);
1034 VMC.ExprMap[I] = NewPN;
1036 while (OldPN->getNumOperands()) {
1037 BasicBlock *BB = OldPN->getIncomingBlock(0);
1038 Value *OldVal = OldPN->getIncomingValue(0);
1039 OldPN->removeIncomingValue(BB);
1040 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
1041 NewPN->addIncoming(V, BB);
1047 case Instruction::Call: {
1048 Value *Meth = I->getOperand(0);
1049 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1051 if (Meth == OldVal) { // Changing the method pointer?
1052 PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1053 MethodType *NewTy = cast<MethodType>(NewPTy->getElementType());
1054 const MethodType::ParamTypes &PTs = NewTy->getParamTypes();
1056 // Convert over all of the call operands to their new types... but only
1057 // convert over the part that is not in the vararg section of the call.
1059 for (unsigned i = 0; i < PTs.size(); ++i)
1060 Params[i] = ConvertExpressionToType(Params[i], PTs[i], VMC);
1061 Meth = NewVal; // Update call destination to new value
1063 } else { // Changing an argument, must be in vararg area
1064 std::vector<Value*>::iterator OI =
1065 find(Params.begin(), Params.end(), OldVal);
1066 assert (OI != Params.end() && "Not using value!");
1071 Res = new CallInst(Meth, Params, Name);
1075 assert(0 && "Expression convertable, but don't know how to convert?");
1079 // If the instruction was newly created, insert it into the instruction
1082 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1083 assert(It != BIL.end() && "Instruction not in own basic block??");
1084 BIL.insert(It, Res); // Keep It pointing to old instruction
1086 #ifdef DEBUG_EXPR_CONVERT
1087 cerr << "COT CREATED: " << (void*)Res << " " << Res;
1088 cerr << "In: " << (void*)I << " " << I << "Out: " << (void*)Res << " " << Res;
1091 // Add the instruction to the expression map
1092 VMC.ExprMap[I] = Res;
1094 if (I->getType() != Res->getType())
1095 ConvertValueToNewType(I, Res, VMC);
1097 for (unsigned It = 0; It < I->use_size(); ) {
1098 User *Use = *(I->use_begin()+It);
1099 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1102 Use->replaceUsesOfWith(I, Res);
1105 if (I->use_empty()) {
1106 // Now we just need to remove the old instruction so we don't get infinite
1107 // loops. Note that we cannot use DCE because DCE won't remove a store
1108 // instruction, for example.
1110 #ifdef DEBUG_EXPR_CONVERT
1111 cerr << "DELETING: " << (void*)I << " " << I;
1114 VMC.OperandsMapped.erase(I);
1115 VMC.ExprMap.erase(I);
1118 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1120 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1126 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1127 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1128 #ifdef DEBUG_EXPR_CONVERT
1129 //cerr << "VH AQUIRING: " << (void*)V << " " << V;
1131 Operands.push_back(Use(V, this));
1134 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1135 if (!I || !I->use_empty()) return;
1137 assert(I->getParent() && "Inst not in basic block!");
1139 #ifdef DEBUG_EXPR_CONVERT
1140 //cerr << "VH DELETING: " << (void*)I << " " << I;
1143 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1145 if (Instruction *U = dyn_cast<Instruction>(*OI)) {
1147 RecursiveDelete(Cache, U);
1150 I->getParent()->getInstList().remove(I);
1152 Cache.OperandsMapped.erase(I);
1153 Cache.ExprMap.erase(I);
1157 ValueHandle::~ValueHandle() {
1158 if (Operands[0]->use_size() == 1) {
1159 Value *V = Operands[0];
1160 Operands[0] = 0; // Drop use!
1162 // Now we just need to remove the old instruction so we don't get infinite
1163 // loops. Note that we cannot use DCE because DCE won't remove a store
1164 // instruction, for example.
1166 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1168 #ifdef DEBUG_EXPR_CONVERT
1169 //cerr << "VH RELEASING: " << (void*)Operands[0].get() << " " << Operands[0]->use_size() << " " << Operands[0];