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/Optimizations/ConstantHandling.h"
16 #include "llvm/Optimizations/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 TODO: This comment is out of date WRT arrays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 (opt::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);
363 #ifdef DEBUG_EXPR_CONVERT
364 cerr << "CETT: " << (void*)V << " " << V;
367 Instruction *I = dyn_cast<Instruction>(V);
369 if (Constant *CPV = cast<Constant>(V)) {
370 // Constants are converted by constant folding the cast that is required.
371 // We assume here that all casts are implemented for constant prop.
372 Value *Result = opt::ConstantFoldCastInstruction(CPV, Ty);
373 assert(Result && "ConstantFoldCastInstruction Failed!!!");
374 assert(Result->getType() == Ty && "Const prop of cast failed!");
376 // Add the instruction to the expression map
377 VMC.ExprMap[V] = Result;
382 BasicBlock *BB = I->getParent();
383 BasicBlock::InstListType &BIL = BB->getInstList();
384 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
385 Instruction *Res; // Result of conversion
387 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
389 Constant *Dummy = Constant::getNullConstant(Ty);
391 switch (I->getOpcode()) {
392 case Instruction::Cast:
393 Res = new CastInst(I->getOperand(0), Ty, Name);
396 case Instruction::Add:
397 case Instruction::Sub:
398 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
400 VMC.ExprMap[I] = Res; // Add node to expression eagerly
402 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
403 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
406 case Instruction::Shl:
407 case Instruction::Shr:
408 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
409 I->getOperand(1), Name);
410 VMC.ExprMap[I] = Res;
411 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
414 case Instruction::Load: {
415 LoadInst *LI = cast<LoadInst>(I);
416 assert(!LI->hasIndices() || AllIndicesZero(LI));
418 Res = new LoadInst(Constant::getNullConstant(PointerType::get(Ty)), Name);
419 VMC.ExprMap[I] = Res;
420 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
421 PointerType::get(Ty), VMC));
422 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
423 assert(Ty == Res->getType());
424 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
428 case Instruction::PHINode: {
429 PHINode *OldPN = cast<PHINode>(I);
430 PHINode *NewPN = new PHINode(Ty, Name);
432 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
433 while (OldPN->getNumOperands()) {
434 BasicBlock *BB = OldPN->getIncomingBlock(0);
435 Value *OldVal = OldPN->getIncomingValue(0);
436 ValueHandle OldValHandle(VMC, OldVal);
437 OldPN->removeIncomingValue(BB);
438 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
439 NewPN->addIncoming(V, BB);
445 case Instruction::Malloc: {
446 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
450 case Instruction::GetElementPtr: {
451 // GetElementPtr's are directly convertable to a pointer type if they have
452 // a number of zeros at the end. Because removing these values does not
453 // change the logical offset of the GEP, it is okay and fair to remove them.
454 // This can change this:
455 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
456 // %t2 = cast %List * * %t1 to %List *
458 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
460 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
462 // Check to see if there are zero elements that we can remove from the
463 // index array. If there are, check to see if removing them causes us to
464 // get to the right type...
466 std::vector<Value*> Indices = GEP->copyIndices();
467 const Type *BaseType = GEP->getPointerOperand()->getType();
468 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
470 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
471 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
473 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
474 if (Indices.size() == 0) {
475 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
477 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
483 if (Res == 0 && GEP->getNumOperands() == 2 &&
484 GEP->getOperand(1)->getType() == Type::UIntTy &&
485 GEP->getType() == PointerType::get(Type::SByteTy)) {
487 // Otherwise, we can convert a GEP from one form to the other iff the
488 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
489 // and we could convert this to an appropriate GEP for the new type.
491 const PointerType *NewSrcTy = PointerType::get(PVTy);
492 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
494 // Check to see if 'N' is an expression that can be converted to
495 // the appropriate size... if so, allow it.
497 std::vector<Value*> Indices;
498 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
501 assert(ElTy == PVTy && "Internal error, setup wrong!");
502 Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
504 VMC.ExprMap[I] = Res;
505 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
510 // Otherwise, it could be that we have something like this:
511 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
512 // and want to convert it into something like this:
513 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
516 const PointerType *NewSrcTy = PointerType::get(PVTy);
517 Res = new GetElementPtrInst(Constant::getNullConstant(NewSrcTy),
518 GEP->copyIndices(), Name);
519 VMC.ExprMap[I] = Res;
520 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
525 assert(Res && "Didn't find match!");
526 break; // No match, maybe next time.
530 assert(0 && "Expression convertable, but don't know how to convert?");
534 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
536 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
537 assert(It != BIL.end() && "Instruction not in own basic block??");
540 // Add the instruction to the expression map
541 VMC.ExprMap[I] = Res;
543 // Expressions are only convertable if all of the users of the expression can
544 // have this value converted. This makes use of the map to avoid infinite
547 unsigned NumUses = I->use_size();
548 for (unsigned It = 0; It < NumUses; ) {
549 unsigned OldSize = NumUses;
550 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
551 NumUses = I->use_size();
552 if (NumUses == OldSize) ++It;
555 #ifdef DEBUG_EXPR_CONVERT
556 cerr << "ExpIn: " << (void*)I << " " << I
557 << "ExpOut: " << (void*)Res << " " << Res;
560 if (I->use_empty()) {
561 #ifdef DEBUG_EXPR_CONVERT
562 cerr << "EXPR DELETING: " << (void*)I << " " << I;
565 VMC.OperandsMapped.erase(I);
566 VMC.ExprMap.erase(I);
575 // ValueConvertableToType - Return true if it is possible
576 bool ValueConvertableToType(Value *V, const Type *Ty,
577 ValueTypeCache &ConvertedTypes) {
578 ValueTypeCache::iterator I = ConvertedTypes.find(V);
579 if (I != ConvertedTypes.end()) return I->second == Ty;
580 ConvertedTypes[V] = Ty;
582 // It is safe to convert the specified value to the specified type IFF all of
583 // the uses of the value can be converted to accept the new typed value.
585 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
586 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
596 // OperandConvertableToType - Return true if it is possible to convert operand
597 // V of User (instruction) U to the specified type. This is true iff it is
598 // possible to change the specified instruction to accept this. CTMap is a map
599 // of converted types, so that circular definitions will see the future type of
600 // the expression, not the static current type.
602 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
603 ValueTypeCache &CTMap) {
604 // if (V->getType() == Ty) return true; // Operand already the right type?
606 // Expression type must be holdable in a register.
607 if (!Ty->isFirstClassType())
610 Instruction *I = dyn_cast<Instruction>(U);
611 if (I == 0) return false; // We can't convert!
613 switch (I->getOpcode()) {
614 case Instruction::Cast:
615 assert(I->getOperand(0) == V);
616 // We can convert the expr if the cast destination type is losslessly
617 // convertable to the requested type.
618 // Also, do not change a cast that is a noop cast. For all intents and
619 // purposes it should be eliminated.
620 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
621 I->getType() == I->getOperand(0)->getType())
626 // We also do not allow conversion of a cast that casts from a ptr to array
627 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
629 if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
630 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
631 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
632 if (AT->getElementType() == DPT->getElementType())
637 case Instruction::Add:
638 if (isa<PointerType>(Ty)) {
639 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
640 std::vector<Value*> Indices;
641 if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
642 const Type *RetTy = PointerType::get(ETy);
644 // Only successful if we can convert this type to the required type
645 if (ValueConvertableToType(I, RetTy, CTMap)) {
649 // We have to return failure here because ValueConvertableToType could
650 // have polluted our map
655 case Instruction::Sub: {
656 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
657 return ValueConvertableToType(I, Ty, CTMap) &&
658 ExpressionConvertableToType(OtherOp, Ty, CTMap);
660 case Instruction::SetEQ:
661 case Instruction::SetNE: {
662 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
663 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
665 case Instruction::Shr:
666 if (Ty->isSigned() != V->getType()->isSigned()) return false;
668 case Instruction::Shl:
669 assert(I->getOperand(0) == V);
670 return ValueConvertableToType(I, Ty, CTMap);
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 if (LI->hasIndices() && !AllIndicesZero(LI))
686 const Type *LoadedTy = PT->getElementType();
688 // They could be loading the first element of a composite type...
689 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
690 unsigned Offset = 0; // No offset, get first leaf.
691 std::vector<Value*> Indices; // Discarded...
692 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
693 assert(Offset == 0 && "Offset changed from zero???");
696 if (!LoadedTy->isFirstClassType())
699 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
702 return ValueConvertableToType(LI, LoadedTy, CTMap);
706 case Instruction::Store: {
707 StoreInst *SI = cast<StoreInst>(I);
708 if (SI->hasIndices()) return false;
710 if (V == I->getOperand(0)) {
711 // Can convert the store if we can convert the pointer operand to match
712 // the new value type...
713 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
715 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
716 const Type *ElTy = PT->getElementType();
717 assert(V == I->getOperand(1));
719 // Must move the same amount of data...
720 if (TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
723 // Can convert store if the incoming value is convertable...
724 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
729 case Instruction::GetElementPtr:
730 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
732 // If we have a two operand form of getelementptr, this is really little
733 // more than a simple addition. As with addition, check to see if the
734 // getelementptr instruction can be changed to index into the new type.
736 if (I->getNumOperands() == 2) {
737 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
738 unsigned DataSize = TD.getTypeSize(OldElTy);
739 Value *Index = I->getOperand(1);
740 Instruction *TempScale = 0;
742 // If the old data element is not unit sized, we have to create a scale
743 // instruction so that ConvertableToGEP will know the REAL amount we are
744 // indexing by. Note that this is never inserted into the instruction
745 // stream, so we have to delete it when we're done.
748 TempScale = BinaryOperator::create(Instruction::Mul, Index,
749 ConstantUInt::get(Type::UIntTy,
754 // Check to see if the second argument is an expression that can
755 // be converted to the appropriate size... if so, allow it.
757 std::vector<Value*> Indices;
758 const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
759 delete TempScale; // Free our temporary multiply if we made it
761 if (ElTy == 0) return false; // Cannot make conversion...
762 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
766 case Instruction::PHINode: {
767 PHINode *PN = cast<PHINode>(I);
768 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
769 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
771 return ValueConvertableToType(PN, Ty, CTMap);
774 case Instruction::Call: {
775 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
776 assert (OI != I->op_end() && "Not using value!");
777 unsigned OpNum = OI - I->op_begin();
780 return false; // Can't convert method pointer type yet. FIXME
782 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
783 const MethodType *MTy = cast<MethodType>(MPtr->getElementType());
784 if (!MTy->isVarArg()) return false;
786 if ((OpNum-1) < MTy->getParamTypes().size())
787 return false; // It's not in the varargs section...
789 // If we get this far, we know the value is in the varargs section of the
790 // method! We can convert if we don't reinterpret the value...
792 return Ty->isLosslesslyConvertableTo(V->getType());
799 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
800 ValueHandle VH(VMC, V);
802 unsigned NumUses = V->use_size();
803 for (unsigned It = 0; It < NumUses; ) {
804 unsigned OldSize = NumUses;
805 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
806 NumUses = V->use_size();
807 if (NumUses == OldSize) ++It;
813 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
814 ValueMapCache &VMC) {
815 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
817 if (VMC.OperandsMapped.count(U)) return;
818 VMC.OperandsMapped.insert(U);
820 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
821 if (VMCI != VMC.ExprMap.end())
825 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
827 BasicBlock *BB = I->getParent();
828 BasicBlock::InstListType &BIL = BB->getInstList();
829 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
830 Instruction *Res; // Result of conversion
832 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
834 // Prevent I from being removed...
835 ValueHandle IHandle(VMC, I);
837 const Type *NewTy = NewVal->getType();
838 Constant *Dummy = (NewTy != Type::VoidTy) ?
839 Constant::getNullConstant(NewTy) : 0;
841 switch (I->getOpcode()) {
842 case Instruction::Cast:
843 assert(I->getOperand(0) == OldVal);
844 Res = new CastInst(NewVal, I->getType(), Name);
847 case Instruction::Add:
848 if (isa<PointerType>(NewTy)) {
849 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
850 std::vector<Value*> Indices;
851 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
853 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
854 // If successful, convert the add to a GEP
855 //const Type *RetTy = PointerType::get(ETy);
856 // First operand is actually the given pointer...
857 Res = new GetElementPtrInst(NewVal, Indices, Name);
858 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
859 "ConvertableToGEP broken!");
865 case Instruction::Sub:
866 case Instruction::SetEQ:
867 case Instruction::SetNE: {
868 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
870 VMC.ExprMap[I] = Res; // Add node to expression eagerly
872 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
873 Value *OtherOp = I->getOperand(OtherIdx);
874 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
876 Res->setOperand(OtherIdx, NewOther);
877 Res->setOperand(!OtherIdx, NewVal);
880 case Instruction::Shl:
881 case Instruction::Shr:
882 assert(I->getOperand(0) == OldVal);
883 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
884 I->getOperand(1), Name);
887 case Instruction::Free: // Free can free any pointer type!
888 assert(I->getOperand(0) == OldVal);
889 Res = new FreeInst(NewVal);
893 case Instruction::Load: {
894 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
895 const Type *LoadedTy =
896 cast<PointerType>(NewVal->getType())->getElementType();
898 std::vector<Value*> Indices;
899 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
901 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
902 unsigned Offset = 0; // No offset, get first leaf.
903 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
905 assert(LoadedTy->isFirstClassType());
907 Res = new LoadInst(NewVal, Indices, Name);
908 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
912 case Instruction::Store: {
913 if (I->getOperand(0) == OldVal) { // Replace the source value
914 const PointerType *NewPT = PointerType::get(NewTy);
915 Res = new StoreInst(NewVal, Constant::getNullConstant(NewPT));
916 VMC.ExprMap[I] = Res;
917 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC));
918 } else { // Replace the source pointer
919 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
920 std::vector<Value*> Indices;
922 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
923 while (ArrayType *AT = dyn_cast<ArrayType>(ValTy)) {
924 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
925 ValTy = AT->getElementType();
928 Res = new StoreInst(Constant::getNullConstant(ValTy), NewVal, Indices);
929 VMC.ExprMap[I] = Res;
930 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
936 case Instruction::GetElementPtr: {
937 // Convert a one index getelementptr into just about anything that is
940 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
941 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
942 unsigned DataSize = TD.getTypeSize(OldElTy);
943 Value *Index = I->getOperand(1);
946 // Insert a multiply of the old element type is not a unit size...
947 Index = BinaryOperator::create(Instruction::Mul, Index,
948 ConstantUInt::get(Type::UIntTy, DataSize));
949 It = BIL.insert(It, cast<Instruction>(Index))+1;
952 // Perform the conversion now...
954 std::vector<Value*> Indices;
955 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
956 assert(ElTy != 0 && "GEP Conversion Failure!");
957 Res = new GetElementPtrInst(NewVal, Indices, Name);
958 assert(Res->getType() == PointerType::get(ElTy) &&
959 "ConvertableToGet failed!");
962 if (I->getType() == PointerType::get(Type::SByteTy)) {
963 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
964 // anything that is a pointer type...
966 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
968 // Check to see if the second argument is an expression that can
969 // be converted to the appropriate size... if so, allow it.
971 std::vector<Value*> Indices;
972 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
974 assert(ElTy != 0 && "GEP Conversion Failure!");
976 Res = new GetElementPtrInst(NewVal, Indices, Name);
978 // Convert a getelementptr ulong * %reg123, uint %N
979 // to getelementptr long * %reg123, uint %N
980 // ... where the type must simply stay the same size...
982 Res = new GetElementPtrInst(NewVal,
983 cast<GetElementPtrInst>(I)->copyIndices(),
989 case Instruction::PHINode: {
990 PHINode *OldPN = cast<PHINode>(I);
991 PHINode *NewPN = new PHINode(NewTy, Name);
992 VMC.ExprMap[I] = NewPN;
994 while (OldPN->getNumOperands()) {
995 BasicBlock *BB = OldPN->getIncomingBlock(0);
996 Value *OldVal = OldPN->getIncomingValue(0);
997 OldPN->removeIncomingValue(BB);
998 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
999 NewPN->addIncoming(V, BB);
1005 case Instruction::Call: {
1006 Value *Meth = I->getOperand(0);
1007 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1009 std::vector<Value*>::iterator OI =
1010 find(Params.begin(), Params.end(), OldVal);
1011 assert (OI != Params.end() && "Not using value!");
1014 Res = new CallInst(Meth, Params, Name);
1018 assert(0 && "Expression convertable, but don't know how to convert?");
1022 // If the instruction was newly created, insert it into the instruction
1025 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1026 assert(It != BIL.end() && "Instruction not in own basic block??");
1027 BIL.insert(It, Res); // Keep It pointing to old instruction
1029 #ifdef DEBUG_EXPR_CONVERT
1030 cerr << "COT CREATED: " << (void*)Res << " " << Res;
1031 cerr << "In: " << (void*)I << " " << I << "Out: " << (void*)Res << " " << Res;
1034 // Add the instruction to the expression map
1035 VMC.ExprMap[I] = Res;
1037 if (I->getType() != Res->getType())
1038 ConvertValueToNewType(I, Res, VMC);
1040 for (unsigned It = 0; It < I->use_size(); ) {
1041 User *Use = *(I->use_begin()+It);
1042 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1045 Use->replaceUsesOfWith(I, Res);
1048 if (I->use_empty()) {
1049 // Now we just need to remove the old instruction so we don't get infinite
1050 // loops. Note that we cannot use DCE because DCE won't remove a store
1051 // instruction, for example.
1053 #ifdef DEBUG_EXPR_CONVERT
1054 cerr << "DELETING: " << (void*)I << " " << I;
1057 VMC.OperandsMapped.erase(I);
1058 VMC.ExprMap.erase(I);
1061 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1063 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1069 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1070 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1071 #ifdef DEBUG_EXPR_CONVERT
1072 //cerr << "VH AQUIRING: " << (void*)V << " " << V;
1074 Operands.push_back(Use(V, this));
1077 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1078 if (!I || !I->use_empty()) return;
1080 assert(I->getParent() && "Inst not in basic block!");
1082 #ifdef DEBUG_EXPR_CONVERT
1083 //cerr << "VH DELETING: " << (void*)I << " " << I;
1086 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1088 Instruction *U = dyn_cast<Instruction>(*OI);
1091 RecursiveDelete(Cache, dyn_cast<Instruction>(U));
1095 I->getParent()->getInstList().remove(I);
1097 Cache.OperandsMapped.erase(I);
1098 Cache.ExprMap.erase(I);
1102 ValueHandle::~ValueHandle() {
1103 if (Operands[0]->use_size() == 1) {
1104 Value *V = Operands[0];
1105 Operands[0] = 0; // Drop use!
1107 // Now we just need to remove the old instruction so we don't get infinite
1108 // loops. Note that we cannot use DCE because DCE won't remove a store
1109 // instruction, for example.
1111 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1113 #ifdef DEBUG_EXPR_CONVERT
1114 //cerr << "VH RELEASING: " << (void*)Operands[0].get() << " " << Operands[0]->use_size() << " " << Operands[0];