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 TODO: This comment is out of date WRT arrays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 (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
62 // Deal with the type to allocate, not the pointer type...
63 Ty = cast<PointerType>(Ty)->getElementType();
64 if (!Ty->isSized()) return false; // Can only alloc something with a size
66 // Analyze the number of bytes allocated...
67 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
69 // Get information about the base datatype being allocated, before & after
70 unsigned ReqTypeSize = TD.getTypeSize(Ty);
71 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
73 // Must have a scale or offset to analyze it...
74 if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
76 // Get the offset and scale of the allocation...
77 int OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
78 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
79 if (ScaleVal < 0 || OffsetVal < 0) {
80 cerr << "malloc of a negative number???\n";
84 // The old type might not be of unit size, take old size into consideration
86 unsigned Offset = (unsigned)OffsetVal * OldTypeSize;
87 unsigned Scale = (unsigned)ScaleVal * OldTypeSize;
89 // In order to be successful, both the scale and the offset must be a multiple
90 // of the requested data type's size.
92 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
93 Scale/ReqTypeSize*ReqTypeSize != Scale)
94 return false; // Nope.
99 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
100 const std::string &Name,
102 BasicBlock *BB = MI->getParent();
103 BasicBlock::iterator It = BB->end();
105 // Analyze the number of bytes allocated...
106 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
108 const PointerType *AllocTy = cast<PointerType>(Ty);
109 const Type *ElType = AllocTy->getElementType();
111 unsigned DataSize = TD.getTypeSize(ElType);
112 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
114 // Get the offset and scale coefficients that we are allocating...
115 int OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
116 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
118 // The old type might not be of unit size, take old size into consideration
120 unsigned Offset = (unsigned)OffsetVal * OldTypeSize / DataSize;
121 unsigned Scale = (unsigned)ScaleVal * OldTypeSize / DataSize;
123 // Locate the malloc instruction, because we may be inserting instructions
124 It = find(BB->getInstList().begin(), BB->getInstList().end(), MI);
126 // If we have a scale, apply it first...
128 // Expr.Var is not neccesarily unsigned right now, insert a cast now.
129 if (Expr.Var->getType() != Type::UIntTy) {
130 Instruction *CI = new CastInst(Expr.Var, Type::UIntTy);
131 if (Expr.Var->hasName()) CI->setName(Expr.Var->getName()+"-uint");
132 It = BB->getInstList().insert(It, CI)+1;
138 BinaryOperator::create(Instruction::Mul, Expr.Var,
139 ConstantUInt::get(Type::UIntTy, Scale));
140 if (Expr.Var->hasName()) ScI->setName(Expr.Var->getName()+"-scl");
141 It = BB->getInstList().insert(It, ScI)+1;
146 // If we are not scaling anything, just make the offset be the "var"...
147 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
148 Offset = 0; Scale = 1;
151 // If we have an offset now, add it in...
153 assert(Expr.Var && "Var must be nonnull by now!");
156 BinaryOperator::create(Instruction::Add, Expr.Var,
157 ConstantUInt::get(Type::UIntTy, Offset));
158 if (Expr.Var->hasName()) AddI->setName(Expr.Var->getName()+"-off");
159 It = BB->getInstList().insert(It, AddI)+1;
163 Instruction *NewI = new MallocInst(AllocTy, Expr.Var, Name);
165 assert(AllocTy == Ty);
170 // ExpressionConvertableToType - Return true if it is possible
171 bool ExpressionConvertableToType(Value *V, const Type *Ty,
172 ValueTypeCache &CTMap) {
173 if (V->getType() == Ty) return true; // Expression already correct type!
175 // Expression type must be holdable in a register.
176 if (!Ty->isFirstClassType())
179 ValueTypeCache::iterator CTMI = CTMap.find(V);
180 if (CTMI != CTMap.end()) return CTMI->second == Ty;
184 Instruction *I = dyn_cast<Instruction>(V);
186 // It's not an instruction, check to see if it's a constant... all constants
187 // can be converted to an equivalent value (except pointers, they can't be
188 // const prop'd in general). We just ask the constant propogator to see if
189 // it can convert the value...
191 if (Constant *CPV = dyn_cast<Constant>(V))
192 if (ConstantFoldCastInstruction(CPV, Ty))
193 return true; // Don't worry about deallocating, it's a constant.
195 return false; // Otherwise, we can't convert!
198 switch (I->getOpcode()) {
199 case Instruction::Cast:
200 // We can convert the expr if the cast destination type is losslessly
201 // convertable to the requested type.
202 if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
204 // We also do not allow conversion of a cast that casts from a ptr to array
205 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
207 if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
208 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
209 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
210 if (AT->getElementType() == DPT->getElementType())
215 case Instruction::Add:
216 case Instruction::Sub:
217 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
218 !ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
221 case Instruction::Shr:
222 if (Ty->isSigned() != V->getType()->isSigned()) return false;
224 case Instruction::Shl:
225 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
229 case Instruction::Load: {
230 LoadInst *LI = cast<LoadInst>(I);
231 if (LI->hasIndices() && !AllIndicesZero(LI)) {
232 // We can't convert a load expression if it has indices... unless they are
237 if (!ExpressionConvertableToType(LI->getPointerOperand(),
238 PointerType::get(Ty), CTMap))
242 case Instruction::PHINode: {
243 PHINode *PN = cast<PHINode>(I);
244 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
245 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
250 case Instruction::Malloc:
251 if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
256 case Instruction::GetElementPtr: {
257 // GetElementPtr's are directly convertable to a pointer type if they have
258 // a number of zeros at the end. Because removing these values does not
259 // change the logical offset of the GEP, it is okay and fair to remove them.
260 // This can change this:
261 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
262 // %t2 = cast %List * * %t1 to %List *
264 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
266 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
267 const PointerType *PTy = dyn_cast<PointerType>(Ty);
268 if (!PTy) return false; // GEP must always return a pointer...
269 const Type *PVTy = PTy->getElementType();
271 // Check to see if there are zero elements that we can remove from the
272 // index array. If there are, check to see if removing them causes us to
273 // get to the right type...
275 std::vector<Value*> Indices = GEP->copyIndices();
276 const Type *BaseType = GEP->getPointerOperand()->getType();
277 const Type *ElTy = 0;
279 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
280 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
282 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
284 break; // Found a match!!
288 if (ElTy) break; // Found a number of zeros we can strip off!
290 // Otherwise, we can convert a GEP from one form to the other iff the
291 // current gep is of the form 'getelementptr sbyte*, unsigned N
292 // and we could convert this to an appropriate GEP for the new type.
294 if (GEP->getNumOperands() == 2 &&
295 GEP->getOperand(1)->getType() == Type::UIntTy &&
296 GEP->getType() == PointerType::get(Type::SByteTy)) {
298 // Do not Check to see if our incoming pointer can be converted
299 // to be a ptr to an array of the right type... because in more cases than
300 // not, it is simply not analyzable because of pointer/array
301 // discrepencies. To fix this, we will insert a cast before the GEP.
304 // Check to see if 'N' is an expression that can be converted to
305 // the appropriate size... if so, allow it.
307 std::vector<Value*> Indices;
308 const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
310 if (!ExpressionConvertableToType(I->getOperand(0),
311 PointerType::get(ElTy), CTMap))
312 return false; // Can't continue, ExConToTy might have polluted set!
317 // Otherwise, it could be that we have something like this:
318 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
319 // and want to convert it into something like this:
320 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
322 if (GEP->getNumOperands() == 2 &&
323 GEP->getOperand(1)->getType() == Type::UIntTy &&
324 TD.getTypeSize(PTy->getElementType()) ==
325 TD.getTypeSize(GEP->getType()->getElementType())) {
326 const PointerType *NewSrcTy = PointerType::get(PVTy);
327 if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
332 return false; // No match, maybe next time.
340 // Expressions are only convertable if all of the users of the expression can
341 // have this value converted. This makes use of the map to avoid infinite
344 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
345 if (!OperandConvertableToType(*It, I, Ty, CTMap))
352 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
353 if (V->getType() == Ty) return V; // Already where we need to be?
355 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
356 if (VMCI != VMC.ExprMap.end()) {
357 assert(VMCI->second->getType() == Ty);
359 if (Instruction *I = dyn_cast<Instruction>(V))
360 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
365 #ifdef DEBUG_EXPR_CONVERT
366 cerr << "CETT: " << (void*)V << " " << V;
369 Instruction *I = dyn_cast<Instruction>(V);
371 if (Constant *CPV = cast<Constant>(V)) {
372 // Constants are converted by constant folding the cast that is required.
373 // We assume here that all casts are implemented for constant prop.
374 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
375 assert(Result && "ConstantFoldCastInstruction Failed!!!");
376 assert(Result->getType() == Ty && "Const prop of cast failed!");
378 // Add the instruction to the expression map
379 VMC.ExprMap[V] = Result;
384 BasicBlock *BB = I->getParent();
385 BasicBlock::InstListType &BIL = BB->getInstList();
386 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
387 Instruction *Res; // Result of conversion
389 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
391 Constant *Dummy = Constant::getNullConstant(Ty);
393 switch (I->getOpcode()) {
394 case Instruction::Cast:
395 Res = new CastInst(I->getOperand(0), Ty, Name);
398 case Instruction::Add:
399 case Instruction::Sub:
400 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
402 VMC.ExprMap[I] = Res; // Add node to expression eagerly
404 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
405 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
408 case Instruction::Shl:
409 case Instruction::Shr:
410 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
411 I->getOperand(1), Name);
412 VMC.ExprMap[I] = Res;
413 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
416 case Instruction::Load: {
417 LoadInst *LI = cast<LoadInst>(I);
418 assert(!LI->hasIndices() || AllIndicesZero(LI));
420 Res = new LoadInst(Constant::getNullConstant(PointerType::get(Ty)), Name);
421 VMC.ExprMap[I] = Res;
422 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
423 PointerType::get(Ty), VMC));
424 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
425 assert(Ty == Res->getType());
426 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
430 case Instruction::PHINode: {
431 PHINode *OldPN = cast<PHINode>(I);
432 PHINode *NewPN = new PHINode(Ty, Name);
434 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
435 while (OldPN->getNumOperands()) {
436 BasicBlock *BB = OldPN->getIncomingBlock(0);
437 Value *OldVal = OldPN->getIncomingValue(0);
438 ValueHandle OldValHandle(VMC, OldVal);
439 OldPN->removeIncomingValue(BB);
440 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
441 NewPN->addIncoming(V, BB);
447 case Instruction::Malloc: {
448 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
452 case Instruction::GetElementPtr: {
453 // GetElementPtr's are directly convertable to a pointer type if they have
454 // a number of zeros at the end. Because removing these values does not
455 // change the logical offset of the GEP, it is okay and fair to remove them.
456 // This can change this:
457 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
458 // %t2 = cast %List * * %t1 to %List *
460 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
462 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
464 // Check to see if there are zero elements that we can remove from the
465 // index array. If there are, check to see if removing them causes us to
466 // get to the right type...
468 std::vector<Value*> Indices = GEP->copyIndices();
469 const Type *BaseType = GEP->getPointerOperand()->getType();
470 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
472 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
473 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
475 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
476 if (Indices.size() == 0) {
477 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
479 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
485 if (Res == 0 && GEP->getNumOperands() == 2 &&
486 GEP->getOperand(1)->getType() == Type::UIntTy &&
487 GEP->getType() == PointerType::get(Type::SByteTy)) {
489 // Otherwise, we can convert a GEP from one form to the other iff the
490 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
491 // and we could convert this to an appropriate GEP for the new type.
493 const PointerType *NewSrcTy = PointerType::get(PVTy);
494 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
496 // Check to see if 'N' is an expression that can be converted to
497 // the appropriate size... if so, allow it.
499 std::vector<Value*> Indices;
500 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
503 assert(ElTy == PVTy && "Internal error, setup wrong!");
504 Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
506 VMC.ExprMap[I] = Res;
507 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
512 // Otherwise, it could be that we have something like this:
513 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
514 // and want to convert it into something like this:
515 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
518 const PointerType *NewSrcTy = PointerType::get(PVTy);
519 Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
520 GEP->copyIndices(), Name);
521 VMC.ExprMap[I] = Res;
522 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
527 assert(Res && "Didn't find match!");
528 break; // No match, maybe next time.
532 assert(0 && "Expression convertable, but don't know how to convert?");
536 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
538 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
539 assert(It != BIL.end() && "Instruction not in own basic block??");
542 // Add the instruction to the expression map
543 VMC.ExprMap[I] = Res;
545 // Expressions are only convertable if all of the users of the expression can
546 // have this value converted. This makes use of the map to avoid infinite
549 unsigned NumUses = I->use_size();
550 for (unsigned It = 0; It < NumUses; ) {
551 unsigned OldSize = NumUses;
552 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
553 NumUses = I->use_size();
554 if (NumUses == OldSize) ++It;
557 #ifdef DEBUG_EXPR_CONVERT
558 cerr << "ExpIn: " << (void*)I << " " << I
559 << "ExpOut: " << (void*)Res << " " << Res;
562 if (I->use_empty()) {
563 #ifdef DEBUG_EXPR_CONVERT
564 cerr << "EXPR DELETING: " << (void*)I << " " << I;
567 VMC.OperandsMapped.erase(I);
568 VMC.ExprMap.erase(I);
577 // ValueConvertableToType - Return true if it is possible
578 bool ValueConvertableToType(Value *V, const Type *Ty,
579 ValueTypeCache &ConvertedTypes) {
580 ValueTypeCache::iterator I = ConvertedTypes.find(V);
581 if (I != ConvertedTypes.end()) return I->second == Ty;
582 ConvertedTypes[V] = Ty;
584 // It is safe to convert the specified value to the specified type IFF all of
585 // the uses of the value can be converted to accept the new typed value.
587 if (V->getType() != Ty) {
588 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
589 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
600 // OperandConvertableToType - Return true if it is possible to convert operand
601 // V of User (instruction) U to the specified type. This is true iff it is
602 // possible to change the specified instruction to accept this. CTMap is a map
603 // of converted types, so that circular definitions will see the future type of
604 // the expression, not the static current type.
606 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
607 ValueTypeCache &CTMap) {
608 // if (V->getType() == Ty) return true; // Operand already the right type?
610 // Expression type must be holdable in a register.
611 if (!Ty->isFirstClassType())
614 Instruction *I = dyn_cast<Instruction>(U);
615 if (I == 0) return false; // We can't convert!
617 switch (I->getOpcode()) {
618 case Instruction::Cast:
619 assert(I->getOperand(0) == V);
620 // We can convert the expr if the cast destination type is losslessly
621 // convertable to the requested type.
622 // Also, do not change a cast that is a noop cast. For all intents and
623 // purposes it should be eliminated.
624 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
625 I->getType() == I->getOperand(0)->getType())
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 (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
634 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
635 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
636 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 = ConvertableToGEP(Ty, IndexVal, Indices)) {
646 const Type *RetTy = PointerType::get(ETy);
648 // Only successful if we can convert this type to the required type
649 if (ValueConvertableToType(I, RetTy, CTMap)) {
653 // We have to return failure here because ValueConvertableToType could
654 // have polluted our map
659 case Instruction::Sub: {
660 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
661 return ValueConvertableToType(I, Ty, CTMap) &&
662 ExpressionConvertableToType(OtherOp, Ty, CTMap);
664 case Instruction::SetEQ:
665 case Instruction::SetNE: {
666 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
667 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
669 case Instruction::Shr:
670 if (Ty->isSigned() != V->getType()->isSigned()) return false;
672 case Instruction::Shl:
673 assert(I->getOperand(0) == V);
674 return ValueConvertableToType(I, Ty, CTMap);
676 case Instruction::Free:
677 assert(I->getOperand(0) == V);
678 return isa<PointerType>(Ty); // Free can free any pointer type!
680 case Instruction::Load:
681 // Cannot convert the types of any subscripts...
682 if (I->getOperand(0) != V) return false;
684 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
685 LoadInst *LI = cast<LoadInst>(I);
687 if (LI->hasIndices() && !AllIndicesZero(LI))
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, false);
697 assert(Offset == 0 && "Offset changed from zero???");
700 if (!LoadedTy->isFirstClassType())
703 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
706 return ValueConvertableToType(LI, LoadedTy, CTMap);
710 case Instruction::Store: {
711 StoreInst *SI = cast<StoreInst>(I);
712 if (SI->hasIndices()) return false;
714 if (V == I->getOperand(0)) {
715 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
716 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
717 // If so, check to see if it's Ty*, or, more importantly, if it is a
718 // pointer to a structure where the first element is a Ty... this code
719 // is neccesary because we might be trying to change the source and
720 // destination type of the store (they might be related) and the dest
721 // pointer type might be a pointer to structure. Below we allow pointer
722 // to structures where the 0th element is compatible with the value,
723 // now we have to support the symmetrical part of this.
725 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
727 // Already a pointer to what we want? Trivially accept...
728 if (ElTy == Ty) return true;
730 // Tricky case now, if the destination is a pointer to structure,
731 // obviously the source is not allowed to be a structure (cannot copy
732 // a whole structure at a time), so the level raiser must be trying to
733 // store into the first field. Check for this and allow it now:
735 if (StructType *SElTy = dyn_cast<StructType>(ElTy)) {
737 std::vector<Value*> Indices;
738 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
739 assert(Offset == 0 && "Offset changed!");
740 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
741 return false; // Can only happen for {}*
743 if (ElTy == Ty) // Looks like the 0th element of structure is
744 return true; // compatible! Accept now!
746 // Otherwise we know that we can't work, so just stop trying now.
751 // Can convert the store if we can convert the pointer operand to match
752 // the new value type...
753 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
755 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
756 const Type *ElTy = PT->getElementType();
757 assert(V == I->getOperand(1));
759 if (isa<StructType>(ElTy)) {
760 // We can change the destination pointer if we can store our first
761 // argument into the first element of the structure...
764 std::vector<Value*> Indices;
765 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
766 assert(Offset == 0 && "Offset changed!");
767 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
768 return false; // Can only happen for {}*
771 // Must move the same amount of data...
772 if (TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
775 // Can convert store if the incoming value is convertable...
776 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
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 ConvertableToGEP 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 ConstantUInt::get(Type::UIntTy,
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 = ConvertableToGEP(Ty, Index, Indices);
811 delete TempScale; // Free our temporary multiply if we made it
813 if (ElTy == 0) return false; // Cannot make conversion...
814 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
818 case Instruction::PHINode: {
819 PHINode *PN = cast<PHINode>(I);
820 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
821 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
823 return ValueConvertableToType(PN, Ty, CTMap);
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 method pointer value to a new type?
833 PointerType *PTy = dyn_cast<PointerType>(Ty);
834 if (PTy == 0) return false; // Can't convert to a non-pointer type...
835 MethodType *MTy = dyn_cast<MethodType>(PTy->getElementType());
836 if (MTy == 0) return false; // Can't convert to a non ptr to method...
838 // Perform sanity checks to make sure that new method type has the
839 // correct number of arguments...
841 unsigned NumArgs = I->getNumOperands()-1; // Don't include method ptr
843 // Cannot convert to a type that requires more fixed arguments than
844 // the call provides...
846 if (NumArgs < MTy->getParamTypes().size()) return false;
848 // Unless this is a vararg method type, we cannot provide more arguments
849 // than are desired...
851 if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
854 // Okay, at this point, we know that the call and the method type match
855 // number of arguments. Now we see if we can convert the arguments
856 // themselves. Note that we do not require operands to be convertable,
857 // we can insert casts if they are convertible but not compatible. The
858 // reason for this is that we prefer to have resolved methods but casted
859 // arguments if possible.
861 const MethodType::ParamTypes &PTs = MTy->getParamTypes();
862 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
863 if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
864 return false; // Operands must have compatible types!
866 // Okay, at this point, we know that all of the arguments can be
867 // converted. We succeed if we can change the return type if
870 return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
873 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
874 const MethodType *MTy = cast<MethodType>(MPtr->getElementType());
875 if (!MTy->isVarArg()) return false;
877 if ((OpNum-1) < MTy->getParamTypes().size())
878 return false; // It's not in the varargs section...
880 // If we get this far, we know the value is in the varargs section of the
881 // method! We can convert if we don't reinterpret the value...
883 return Ty->isLosslesslyConvertableTo(V->getType());
890 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
891 ValueHandle VH(VMC, V);
893 unsigned NumUses = V->use_size();
894 for (unsigned It = 0; It < NumUses; ) {
895 unsigned OldSize = NumUses;
896 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
897 NumUses = V->use_size();
898 if (NumUses == OldSize) ++It;
904 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
905 ValueMapCache &VMC) {
906 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
908 if (VMC.OperandsMapped.count(U)) return;
909 VMC.OperandsMapped.insert(U);
911 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
912 if (VMCI != VMC.ExprMap.end())
916 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
918 BasicBlock *BB = I->getParent();
919 BasicBlock::InstListType &BIL = BB->getInstList();
920 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
921 Instruction *Res; // Result of conversion
923 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
925 // Prevent I from being removed...
926 ValueHandle IHandle(VMC, I);
928 const Type *NewTy = NewVal->getType();
929 Constant *Dummy = (NewTy != Type::VoidTy) ?
930 Constant::getNullConstant(NewTy) : 0;
932 switch (I->getOpcode()) {
933 case Instruction::Cast:
934 assert(I->getOperand(0) == OldVal);
935 Res = new CastInst(NewVal, I->getType(), Name);
938 case Instruction::Add:
939 if (isa<PointerType>(NewTy)) {
940 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
941 std::vector<Value*> Indices;
942 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
944 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
945 // If successful, convert the add to a GEP
946 //const Type *RetTy = PointerType::get(ETy);
947 // First operand is actually the given pointer...
948 Res = new GetElementPtrInst(NewVal, Indices, Name);
949 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
950 "ConvertableToGEP broken!");
956 case Instruction::Sub:
957 case Instruction::SetEQ:
958 case Instruction::SetNE: {
959 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
961 VMC.ExprMap[I] = Res; // Add node to expression eagerly
963 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
964 Value *OtherOp = I->getOperand(OtherIdx);
965 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
967 Res->setOperand(OtherIdx, NewOther);
968 Res->setOperand(!OtherIdx, NewVal);
971 case Instruction::Shl:
972 case Instruction::Shr:
973 assert(I->getOperand(0) == OldVal);
974 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
975 I->getOperand(1), Name);
978 case Instruction::Free: // Free can free any pointer type!
979 assert(I->getOperand(0) == OldVal);
980 Res = new FreeInst(NewVal);
984 case Instruction::Load: {
985 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
986 const Type *LoadedTy =
987 cast<PointerType>(NewVal->getType())->getElementType();
989 std::vector<Value*> Indices;
990 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
992 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
993 unsigned Offset = 0; // No offset, get first leaf.
994 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
996 assert(LoadedTy->isFirstClassType());
998 Res = new LoadInst(NewVal, Indices, Name);
999 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
1003 case Instruction::Store: {
1004 if (I->getOperand(0) == OldVal) { // Replace the source value
1005 const PointerType *NewPT = PointerType::get(NewTy);
1006 Res = new StoreInst(NewVal, Constant::getNullConstant(NewPT));
1007 VMC.ExprMap[I] = Res;
1008 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC));
1009 } else { // Replace the source pointer
1010 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1011 std::vector<Value*> Indices;
1013 if (isa<StructType>(ValTy)) {
1014 unsigned Offset = 0;
1015 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
1016 ValTy = getStructOffsetType(ValTy, Offset, Indices, false);
1017 assert(Offset == 0 && ValTy);
1020 Res = new StoreInst(Constant::getNullConstant(ValTy), NewVal, Indices);
1021 VMC.ExprMap[I] = Res;
1022 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
1028 case Instruction::GetElementPtr: {
1029 // Convert a one index getelementptr into just about anything that is
1032 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1033 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
1034 unsigned DataSize = TD.getTypeSize(OldElTy);
1035 Value *Index = I->getOperand(1);
1037 if (DataSize != 1) {
1038 // Insert a multiply of the old element type is not a unit size...
1039 Index = BinaryOperator::create(Instruction::Mul, Index,
1040 ConstantUInt::get(Type::UIntTy, DataSize));
1041 It = BIL.insert(It, cast<Instruction>(Index))+1;
1044 // Perform the conversion now...
1046 std::vector<Value*> Indices;
1047 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
1048 assert(ElTy != 0 && "GEP Conversion Failure!");
1049 Res = new GetElementPtrInst(NewVal, Indices, Name);
1050 assert(Res->getType() == PointerType::get(ElTy) &&
1051 "ConvertableToGet failed!");
1054 if (I->getType() == PointerType::get(Type::SByteTy)) {
1055 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1056 // anything that is a pointer type...
1058 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1060 // Check to see if the second argument is an expression that can
1061 // be converted to the appropriate size... if so, allow it.
1063 std::vector<Value*> Indices;
1064 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
1066 assert(ElTy != 0 && "GEP Conversion Failure!");
1068 Res = new GetElementPtrInst(NewVal, Indices, Name);
1070 // Convert a getelementptr ulong * %reg123, uint %N
1071 // to getelementptr long * %reg123, uint %N
1072 // ... where the type must simply stay the same size...
1074 Res = new GetElementPtrInst(NewVal,
1075 cast<GetElementPtrInst>(I)->copyIndices(),
1081 case Instruction::PHINode: {
1082 PHINode *OldPN = cast<PHINode>(I);
1083 PHINode *NewPN = new PHINode(NewTy, Name);
1084 VMC.ExprMap[I] = NewPN;
1086 while (OldPN->getNumOperands()) {
1087 BasicBlock *BB = OldPN->getIncomingBlock(0);
1088 Value *OldVal = OldPN->getIncomingValue(0);
1089 OldPN->removeIncomingValue(BB);
1090 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
1091 NewPN->addIncoming(V, BB);
1097 case Instruction::Call: {
1098 Value *Meth = I->getOperand(0);
1099 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1101 if (Meth == OldVal) { // Changing the method pointer?
1102 PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1103 MethodType *NewTy = cast<MethodType>(NewPTy->getElementType());
1104 const MethodType::ParamTypes &PTs = NewTy->getParamTypes();
1106 // Get an iterator to the call instruction so that we can insert casts for
1107 // operands if needbe. Note that we do not require operands to be
1108 // convertable, we can insert casts if they are convertible but not
1109 // compatible. The reason for this is that we prefer to have resolved
1110 // methods but casted arguments if possible.
1112 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1114 // Convert over all of the call operands to their new types... but only
1115 // convert over the part that is not in the vararg section of the call.
1117 for (unsigned i = 0; i < PTs.size(); ++i)
1118 if (Params[i]->getType() != PTs[i]) {
1119 // Create a cast to convert it to the right type, we know that this
1120 // is a lossless cast...
1122 Params[i] = new CastInst(Params[i], PTs[i], "call.resolve.cast");
1123 It = BIL.insert(It, cast<Instruction>(Params[i]))+1;
1125 Meth = NewVal; // Update call destination to new value
1127 } else { // Changing an argument, must be in vararg area
1128 std::vector<Value*>::iterator OI =
1129 find(Params.begin(), Params.end(), OldVal);
1130 assert (OI != Params.end() && "Not using value!");
1135 Res = new CallInst(Meth, Params, Name);
1139 assert(0 && "Expression convertable, but don't know how to convert?");
1143 // If the instruction was newly created, insert it into the instruction
1146 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1147 assert(It != BIL.end() && "Instruction not in own basic block??");
1148 BIL.insert(It, Res); // Keep It pointing to old instruction
1150 #ifdef DEBUG_EXPR_CONVERT
1151 cerr << "COT CREATED: " << (void*)Res << " " << Res;
1152 cerr << "In: " << (void*)I << " " << I << "Out: " << (void*)Res << " " << Res;
1155 // Add the instruction to the expression map
1156 VMC.ExprMap[I] = Res;
1158 if (I->getType() != Res->getType())
1159 ConvertValueToNewType(I, Res, VMC);
1161 for (unsigned It = 0; It < I->use_size(); ) {
1162 User *Use = *(I->use_begin()+It);
1163 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1166 Use->replaceUsesOfWith(I, Res);
1169 if (I->use_empty()) {
1170 // Now we just need to remove the old instruction so we don't get infinite
1171 // loops. Note that we cannot use DCE because DCE won't remove a store
1172 // instruction, for example.
1174 #ifdef DEBUG_EXPR_CONVERT
1175 cerr << "DELETING: " << (void*)I << " " << I;
1178 VMC.OperandsMapped.erase(I);
1179 VMC.ExprMap.erase(I);
1182 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1184 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1190 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1191 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1192 #ifdef DEBUG_EXPR_CONVERT
1193 //cerr << "VH AQUIRING: " << (void*)V << " " << V;
1195 Operands.push_back(Use(V, this));
1198 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1199 if (!I || !I->use_empty()) return;
1201 assert(I->getParent() && "Inst not in basic block!");
1203 #ifdef DEBUG_EXPR_CONVERT
1204 //cerr << "VH DELETING: " << (void*)I << " " << I;
1207 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1209 if (Instruction *U = dyn_cast<Instruction>(*OI)) {
1211 RecursiveDelete(Cache, U);
1214 I->getParent()->getInstList().remove(I);
1216 Cache.OperandsMapped.erase(I);
1217 Cache.ExprMap.erase(I);
1221 ValueHandle::~ValueHandle() {
1222 if (Operands[0]->use_size() == 1) {
1223 Value *V = Operands[0];
1224 Operands[0] = 0; // Drop use!
1226 // Now we just need to remove the old instruction so we don't get infinite
1227 // loops. Note that we cannot use DCE because DCE won't remove a store
1228 // instruction, for example.
1230 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1232 #ifdef DEBUG_EXPR_CONVERT
1233 //cerr << "VH RELEASING: " << (void*)Operands[0].get() << " " << Operands[0]->use_size() << " " << Operands[0];