diff options
Diffstat (limited to 'lib/Analysis/ScalarEvolutionExpander.cpp')
| -rw-r--r-- | lib/Analysis/ScalarEvolutionExpander.cpp | 482 |
1 files changed, 332 insertions, 150 deletions
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index 729a0c3..d674ee8 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -15,6 +15,7 @@ #include "llvm/Analysis/ScalarEvolutionExpander.h" #include "llvm/Analysis/LoopInfo.h" +#include "llvm/LLVMContext.h" #include "llvm/Target/TargetData.h" #include "llvm/ADT/STLExtras.h" using namespace llvm; @@ -52,10 +53,9 @@ Value *SCEVExpander::InsertNoopCastOfTo(Value *V, const Type *Ty) { return CE->getOperand(0); } - // FIXME: keep track of the cast instruction. if (Constant *C = dyn_cast<Constant>(V)) return ConstantExpr::getCast(Op, C, Ty); - + if (Argument *A = dyn_cast<Argument>(V)) { // Check to see if there is already a cast! for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); @@ -155,55 +155,95 @@ Value *SCEVExpander::InsertBinop(Instruction::BinaryOps Opcode, /// TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made /// unnecessary; in its place, just signed-divide Ops[i] by the scale and /// check to see if the divide was folded. -static bool FactorOutConstant(const SCEV* &S, - const SCEV* &Remainder, - const APInt &Factor, - ScalarEvolution &SE) { +static bool FactorOutConstant(const SCEV *&S, + const SCEV *&Remainder, + const SCEV *Factor, + ScalarEvolution &SE, + const TargetData *TD) { // Everything is divisible by one. - if (Factor == 1) + if (Factor->isOne()) + return true; + + // x/x == 1. + if (S == Factor) { + S = SE.getIntegerSCEV(1, S->getType()); return true; + } // For a Constant, check for a multiple of the given factor. if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) { - ConstantInt *CI = - ConstantInt::get(C->getValue()->getValue().sdiv(Factor)); - // If the quotient is zero and the remainder is non-zero, reject - // the value at this scale. It will be considered for subsequent - // smaller scales. - if (C->isZero() || !CI->isZero()) { - const SCEV* Div = SE.getConstant(CI); - S = Div; - Remainder = - SE.getAddExpr(Remainder, - SE.getConstant(C->getValue()->getValue().srem(Factor))); + // 0/x == 0. + if (C->isZero()) return true; + // Check for divisibility. + if (const SCEVConstant *FC = dyn_cast<SCEVConstant>(Factor)) { + ConstantInt *CI = + ConstantInt::get(SE.getContext(), + C->getValue()->getValue().sdiv( + FC->getValue()->getValue())); + // If the quotient is zero and the remainder is non-zero, reject + // the value at this scale. It will be considered for subsequent + // smaller scales. + if (!CI->isZero()) { + const SCEV *Div = SE.getConstant(CI); + S = Div; + Remainder = + SE.getAddExpr(Remainder, + SE.getConstant(C->getValue()->getValue().srem( + FC->getValue()->getValue()))); + return true; + } } } // In a Mul, check if there is a constant operand which is a multiple // of the given factor. - if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) - if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) - if (!C->getValue()->getValue().srem(Factor)) { - const SmallVectorImpl<const SCEV *> &MOperands = M->getOperands(); - SmallVector<const SCEV *, 4> NewMulOps(MOperands.begin(), - MOperands.end()); - NewMulOps[0] = - SE.getConstant(C->getValue()->getValue().sdiv(Factor)); - S = SE.getMulExpr(NewMulOps); - return true; + if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(S)) { + if (TD) { + // With TargetData, the size is known. Check if there is a constant + // operand which is a multiple of the given factor. If so, we can + // factor it. + const SCEVConstant *FC = cast<SCEVConstant>(Factor); + if (const SCEVConstant *C = dyn_cast<SCEVConstant>(M->getOperand(0))) + if (!C->getValue()->getValue().srem(FC->getValue()->getValue())) { + const SmallVectorImpl<const SCEV *> &MOperands = M->getOperands(); + SmallVector<const SCEV *, 4> NewMulOps(MOperands.begin(), + MOperands.end()); + NewMulOps[0] = + SE.getConstant(C->getValue()->getValue().sdiv( + FC->getValue()->getValue())); + S = SE.getMulExpr(NewMulOps); + return true; + } + } else { + // Without TargetData, check if Factor can be factored out of any of the + // Mul's operands. If so, we can just remove it. + for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) { + const SCEV *SOp = M->getOperand(i); + const SCEV *Remainder = SE.getIntegerSCEV(0, SOp->getType()); + if (FactorOutConstant(SOp, Remainder, Factor, SE, TD) && + Remainder->isZero()) { + const SmallVectorImpl<const SCEV *> &MOperands = M->getOperands(); + SmallVector<const SCEV *, 4> NewMulOps(MOperands.begin(), + MOperands.end()); + NewMulOps[i] = SOp; + S = SE.getMulExpr(NewMulOps); + return true; + } } + } + } // In an AddRec, check if both start and step are divisible. if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(S)) { - const SCEV* Step = A->getStepRecurrence(SE); - const SCEV* StepRem = SE.getIntegerSCEV(0, Step->getType()); - if (!FactorOutConstant(Step, StepRem, Factor, SE)) + const SCEV *Step = A->getStepRecurrence(SE); + const SCEV *StepRem = SE.getIntegerSCEV(0, Step->getType()); + if (!FactorOutConstant(Step, StepRem, Factor, SE, TD)) return false; if (!StepRem->isZero()) return false; - const SCEV* Start = A->getStart(); - if (!FactorOutConstant(Start, Remainder, Factor, SE)) + const SCEV *Start = A->getStart(); + if (!FactorOutConstant(Start, Remainder, Factor, SE, TD)) return false; S = SE.getAddRecExpr(Start, Step, A->getLoop()); return true; @@ -212,15 +252,81 @@ static bool FactorOutConstant(const SCEV* &S, return false; } -/// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP -/// instead of using ptrtoint+arithmetic+inttoptr. This helps -/// BasicAliasAnalysis analyze the result. However, it suffers from the -/// underlying bug described in PR2831. Addition in LLVM currently always -/// has two's complement wrapping guaranteed. However, the semantics for -/// getelementptr overflow are ambiguous. In the common case though, this -/// expansion gets used when a GEP in the original code has been converted -/// into integer arithmetic, in which case the resulting code will be no -/// more undefined than it was originally. +/// SimplifyAddOperands - Sort and simplify a list of add operands. NumAddRecs +/// is the number of SCEVAddRecExprs present, which are kept at the end of +/// the list. +/// +static void SimplifyAddOperands(SmallVectorImpl<const SCEV *> &Ops, + const Type *Ty, + ScalarEvolution &SE) { + unsigned NumAddRecs = 0; + for (unsigned i = Ops.size(); i > 0 && isa<SCEVAddRecExpr>(Ops[i-1]); --i) + ++NumAddRecs; + // Group Ops into non-addrecs and addrecs. + SmallVector<const SCEV *, 8> NoAddRecs(Ops.begin(), Ops.end() - NumAddRecs); + SmallVector<const SCEV *, 8> AddRecs(Ops.end() - NumAddRecs, Ops.end()); + // Let ScalarEvolution sort and simplify the non-addrecs list. + const SCEV *Sum = NoAddRecs.empty() ? + SE.getIntegerSCEV(0, Ty) : + SE.getAddExpr(NoAddRecs); + // If it returned an add, use the operands. Otherwise it simplified + // the sum into a single value, so just use that. + if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Sum)) + Ops = Add->getOperands(); + else { + Ops.clear(); + if (!Sum->isZero()) + Ops.push_back(Sum); + } + // Then append the addrecs. + Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end()); +} + +/// SplitAddRecs - Flatten a list of add operands, moving addrec start values +/// out to the top level. For example, convert {a + b,+,c} to a, b, {0,+,d}. +/// This helps expose more opportunities for folding parts of the expressions +/// into GEP indices. +/// +static void SplitAddRecs(SmallVectorImpl<const SCEV *> &Ops, + const Type *Ty, + ScalarEvolution &SE) { + // Find the addrecs. + SmallVector<const SCEV *, 8> AddRecs; + for (unsigned i = 0, e = Ops.size(); i != e; ++i) + while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) { + const SCEV *Start = A->getStart(); + if (Start->isZero()) break; + const SCEV *Zero = SE.getIntegerSCEV(0, Ty); + AddRecs.push_back(SE.getAddRecExpr(Zero, + A->getStepRecurrence(SE), + A->getLoop())); + if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Start)) { + Ops[i] = Zero; + Ops.insert(Ops.end(), Add->op_begin(), Add->op_end()); + e += Add->getNumOperands(); + } else { + Ops[i] = Start; + } + } + if (!AddRecs.empty()) { + // Add the addrecs onto the end of the list. + Ops.insert(Ops.end(), AddRecs.begin(), AddRecs.end()); + // Resort the operand list, moving any constants to the front. + SimplifyAddOperands(Ops, Ty, SE); + } +} + +/// expandAddToGEP - Expand an addition expression with a pointer type into +/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps +/// BasicAliasAnalysis and other passes analyze the result. See the rules +/// for getelementptr vs. inttoptr in +/// http://llvm.org/docs/LangRef.html#pointeraliasing +/// for details. +/// +/// Design note: The correctness of using getelmeentptr here depends on +/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as +/// they may introduce pointer arithmetic which may not be safely converted +/// into getelementptr. /// /// Design note: It might seem desirable for this function to be more /// loop-aware. If some of the indices are loop-invariant while others @@ -237,92 +343,130 @@ static bool FactorOutConstant(const SCEV* &S, /// loop-invariant portions of expressions, after considering what /// can be folded using target addressing modes. /// -Value *SCEVExpander::expandAddToGEP(const SCEV* const *op_begin, - const SCEV* const *op_end, +Value *SCEVExpander::expandAddToGEP(const SCEV *const *op_begin, + const SCEV *const *op_end, const PointerType *PTy, const Type *Ty, Value *V) { const Type *ElTy = PTy->getElementType(); SmallVector<Value *, 4> GepIndices; - SmallVector<const SCEV*, 8> Ops(op_begin, op_end); + SmallVector<const SCEV *, 8> Ops(op_begin, op_end); bool AnyNonZeroIndices = false; + // Split AddRecs up into parts as either of the parts may be usable + // without the other. + SplitAddRecs(Ops, Ty, SE); + // Decend down the pointer's type and attempt to convert the other // operands into GEP indices, at each level. The first index in a GEP // indexes into the array implied by the pointer operand; the rest of // the indices index into the element or field type selected by the // preceding index. for (;;) { - APInt ElSize = APInt(SE.getTypeSizeInBits(Ty), - ElTy->isSized() ? SE.TD->getTypeAllocSize(ElTy) : 0); - SmallVector<const SCEV*, 8> NewOps; - SmallVector<const SCEV*, 8> ScaledOps; - for (unsigned i = 0, e = Ops.size(); i != e; ++i) { - // Split AddRecs up into parts as either of the parts may be usable - // without the other. - if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Ops[i])) - if (!A->getStart()->isZero()) { - const SCEV* Start = A->getStart(); - Ops.push_back(SE.getAddRecExpr(SE.getIntegerSCEV(0, A->getType()), - A->getStepRecurrence(SE), - A->getLoop())); - Ops[i] = Start; - ++e; - } - // If the scale size is not 0, attempt to factor out a scale. - if (ElSize != 0) { - const SCEV* Op = Ops[i]; - const SCEV* Remainder = SE.getIntegerSCEV(0, Op->getType()); - if (FactorOutConstant(Op, Remainder, ElSize, SE)) { - ScaledOps.push_back(Op); // Op now has ElSize factored out. - NewOps.push_back(Remainder); - continue; + const SCEV *ElSize = SE.getAllocSizeExpr(ElTy); + // If the scale size is not 0, attempt to factor out a scale for + // array indexing. + SmallVector<const SCEV *, 8> ScaledOps; + if (ElTy->isSized() && !ElSize->isZero()) { + SmallVector<const SCEV *, 8> NewOps; + for (unsigned i = 0, e = Ops.size(); i != e; ++i) { + const SCEV *Op = Ops[i]; + const SCEV *Remainder = SE.getIntegerSCEV(0, Ty); + if (FactorOutConstant(Op, Remainder, ElSize, SE, SE.TD)) { + // Op now has ElSize factored out. + ScaledOps.push_back(Op); + if (!Remainder->isZero()) + NewOps.push_back(Remainder); + AnyNonZeroIndices = true; + } else { + // The operand was not divisible, so add it to the list of operands + // we'll scan next iteration. + NewOps.push_back(Ops[i]); } } - // If the operand was not divisible, add it to the list of operands - // we'll scan next iteration. - NewOps.push_back(Ops[i]); + // If we made any changes, update Ops. + if (!ScaledOps.empty()) { + Ops = NewOps; + SimplifyAddOperands(Ops, Ty, SE); + } } - Ops = NewOps; - AnyNonZeroIndices |= !ScaledOps.empty(); + + // Record the scaled array index for this level of the type. If + // we didn't find any operands that could be factored, tentatively + // assume that element zero was selected (since the zero offset + // would obviously be folded away). Value *Scaled = ScaledOps.empty() ? Constant::getNullValue(Ty) : expandCodeFor(SE.getAddExpr(ScaledOps), Ty); GepIndices.push_back(Scaled); // Collect struct field index operands. - if (!Ops.empty()) - while (const StructType *STy = dyn_cast<StructType>(ElTy)) { + while (const StructType *STy = dyn_cast<StructType>(ElTy)) { + bool FoundFieldNo = false; + // An empty struct has no fields. + if (STy->getNumElements() == 0) break; + if (SE.TD) { + // With TargetData, field offsets are known. See if a constant offset + // falls within any of the struct fields. + if (Ops.empty()) break; if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[0])) if (SE.getTypeSizeInBits(C->getType()) <= 64) { const StructLayout &SL = *SE.TD->getStructLayout(STy); uint64_t FullOffset = C->getValue()->getZExtValue(); if (FullOffset < SL.getSizeInBytes()) { unsigned ElIdx = SL.getElementContainingOffset(FullOffset); - GepIndices.push_back(ConstantInt::get(Type::Int32Ty, ElIdx)); + GepIndices.push_back( + ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); ElTy = STy->getTypeAtIndex(ElIdx); Ops[0] = SE.getConstant(Ty, FullOffset - SL.getElementOffset(ElIdx)); AnyNonZeroIndices = true; - continue; + FoundFieldNo = true; } } - break; + } else { + // Without TargetData, just check for a SCEVFieldOffsetExpr of the + // appropriate struct type. + for (unsigned i = 0, e = Ops.size(); i != e; ++i) + if (const SCEVFieldOffsetExpr *FO = + dyn_cast<SCEVFieldOffsetExpr>(Ops[i])) + if (FO->getStructType() == STy) { + unsigned FieldNo = FO->getFieldNo(); + GepIndices.push_back( + ConstantInt::get(Type::getInt32Ty(Ty->getContext()), + FieldNo)); + ElTy = STy->getTypeAtIndex(FieldNo); + Ops[i] = SE.getConstant(Ty, 0); + AnyNonZeroIndices = true; + FoundFieldNo = true; + break; + } + } + // If no struct field offsets were found, tentatively assume that + // field zero was selected (since the zero offset would obviously + // be folded away). + if (!FoundFieldNo) { + ElTy = STy->getTypeAtIndex(0u); + GepIndices.push_back( + Constant::getNullValue(Type::getInt32Ty(Ty->getContext()))); } + } - if (const ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) { + if (const ArrayType *ATy = dyn_cast<ArrayType>(ElTy)) ElTy = ATy->getElementType(); - continue; - } - break; + else + break; } // If none of the operands were convertable to proper GEP indices, cast // the base to i8* and do an ugly getelementptr with that. It's still // better than ptrtoint+arithmetic+inttoptr at least. if (!AnyNonZeroIndices) { + // Cast the base to i8*. V = InsertNoopCastOfTo(V, - Type::Int8Ty->getPointerTo(PTy->getAddressSpace())); + Type::getInt8PtrTy(Ty->getContext(), PTy->getAddressSpace())); + + // Expand the operands for a plain byte offset. Value *Idx = expandCodeFor(SE.getAddExpr(Ops), Ty); // Fold a GEP with constant operands. @@ -345,12 +489,15 @@ Value *SCEVExpander::expandAddToGEP(const SCEV* const *op_begin, } } - Value *GEP = Builder.CreateGEP(V, Idx, "scevgep"); + // Emit a GEP. + Value *GEP = Builder.CreateGEP(V, Idx, "uglygep"); InsertedValues.insert(GEP); return GEP; } - // Insert a pretty getelementptr. + // Insert a pretty getelementptr. Note that this GEP is not marked inbounds, + // because ScalarEvolution may have changed the address arithmetic to + // compute a value which is beyond the end of the allocated object. Value *GEP = Builder.CreateGEP(V, GepIndices.begin(), GepIndices.end(), @@ -361,21 +508,37 @@ Value *SCEVExpander::expandAddToGEP(const SCEV* const *op_begin, } Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) { + int NumOperands = S->getNumOperands(); const Type *Ty = SE.getEffectiveSCEVType(S->getType()); - Value *V = expand(S->getOperand(S->getNumOperands()-1)); + + // Find the index of an operand to start with. Choose the operand with + // pointer type, if there is one, or the last operand otherwise. + int PIdx = 0; + for (; PIdx != NumOperands - 1; ++PIdx) + if (isa<PointerType>(S->getOperand(PIdx)->getType())) break; + + // Expand code for the operand that we chose. + Value *V = expand(S->getOperand(PIdx)); // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the // comments on expandAddToGEP for details. - if (SE.TD) - if (const PointerType *PTy = dyn_cast<PointerType>(V->getType())) { - const SmallVectorImpl<const SCEV*> &Ops = S->getOperands(); - return expandAddToGEP(&Ops[0], &Ops[Ops.size() - 1], PTy, Ty, V); - } + if (const PointerType *PTy = dyn_cast<PointerType>(V->getType())) { + // Take the operand at PIdx out of the list. + const SmallVectorImpl<const SCEV *> &Ops = S->getOperands(); + SmallVector<const SCEV *, 8> NewOps; + NewOps.insert(NewOps.end(), Ops.begin(), Ops.begin() + PIdx); + NewOps.insert(NewOps.end(), Ops.begin() + PIdx + 1, Ops.end()); + // Make a GEP. + return expandAddToGEP(NewOps.begin(), NewOps.end(), PTy, Ty, V); + } + // Otherwise, we'll expand the rest of the SCEVAddExpr as plain integer + // arithmetic. V = InsertNoopCastOfTo(V, Ty); // Emit a bunch of add instructions - for (int i = S->getNumOperands()-2; i >= 0; --i) { + for (int i = NumOperands-1; i >= 0; --i) { + if (i == PIdx) continue; Value *W = expandCodeFor(S->getOperand(i), Ty); V = InsertBinop(Instruction::Add, V, W); } @@ -422,7 +585,7 @@ Value *SCEVExpander::visitUDivExpr(const SCEVUDivExpr *S) { /// Move parts of Base into Rest to leave Base with the minimal /// expression that provides a pointer operand suitable for a /// GEP expansion. -static void ExposePointerBase(const SCEV* &Base, const SCEV* &Rest, +static void ExposePointerBase(const SCEV *&Base, const SCEV *&Rest, ScalarEvolution &SE) { while (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(Base)) { Base = A->getStart(); @@ -433,7 +596,7 @@ static void ExposePointerBase(const SCEV* &Base, const SCEV* &Rest, } if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(Base)) { Base = A->getOperand(A->getNumOperands()-1); - SmallVector<const SCEV*, 8> NewAddOps(A->op_begin(), A->op_end()); + SmallVector<const SCEV *, 8> NewAddOps(A->op_begin(), A->op_end()); NewAddOps.back() = Rest; Rest = SE.getAddExpr(NewAddOps); ExposePointerBase(Base, Rest, SE); @@ -457,11 +620,11 @@ Value *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { if (CanonicalIV && SE.getTypeSizeInBits(CanonicalIV->getType()) > SE.getTypeSizeInBits(Ty)) { - const SCEV *Start = SE.getAnyExtendExpr(S->getStart(), - CanonicalIV->getType()); - const SCEV *Step = SE.getAnyExtendExpr(S->getStepRecurrence(SE), - CanonicalIV->getType()); - Value *V = expand(SE.getAddRecExpr(Start, Step, S->getLoop())); + const SmallVectorImpl<const SCEV *> &Ops = S->getOperands(); + SmallVector<const SCEV *, 4> NewOps(Ops.size()); + for (unsigned i = 0, e = Ops.size(); i != e; ++i) + NewOps[i] = SE.getAnyExtendExpr(Ops[i], CanonicalIV->getType()); + Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop())); BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); BasicBlock::iterator NewInsertPt = @@ -475,28 +638,26 @@ Value *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { // {X,+,F} --> X + {0,+,F} if (!S->getStart()->isZero()) { - const SmallVectorImpl<const SCEV*> &SOperands = S->getOperands(); - SmallVector<const SCEV*, 4> NewOps(SOperands.begin(), SOperands.end()); + const SmallVectorImpl<const SCEV *> &SOperands = S->getOperands(); + SmallVector<const SCEV *, 4> NewOps(SOperands.begin(), SOperands.end()); NewOps[0] = SE.getIntegerSCEV(0, Ty); - const SCEV* Rest = SE.getAddRecExpr(NewOps, L); + const SCEV *Rest = SE.getAddRecExpr(NewOps, L); // Turn things like ptrtoint+arithmetic+inttoptr into GEP. See the // comments on expandAddToGEP for details. - if (SE.TD) { - const SCEV* Base = S->getStart(); - const SCEV* RestArray[1] = { Rest }; - // Dig into the expression to find the pointer base for a GEP. - ExposePointerBase(Base, RestArray[0], SE); - // If we found a pointer, expand the AddRec with a GEP. - if (const PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { - // Make sure the Base isn't something exotic, such as a multiplied - // or divided pointer value. In those cases, the result type isn't - // actually a pointer type. - if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { - Value *StartV = expand(Base); - assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); - return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); - } + const SCEV *Base = S->getStart(); + const SCEV *RestArray[1] = { Rest }; + // Dig into the expression to find the pointer base for a GEP. + ExposePointerBase(Base, RestArray[0], SE); + // If we found a pointer, expand the AddRec with a GEP. + if (const PointerType *PTy = dyn_cast<PointerType>(Base->getType())) { + // Make sure the Base isn't something exotic, such as a multiplied + // or divided pointer value. In those cases, the result type isn't + // actually a pointer type. + if (!isa<SCEVMulExpr>(Base) && !isa<SCEVUDivExpr>(Base)) { + Value *StartV = expand(Base); + assert(StartV->getType() == PTy && "Pointer type mismatch for GEP!"); + return expandAddToGEP(RestArray, RestArray+1, PTy, Ty, StartV); } } @@ -519,29 +680,22 @@ Value *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { // Create and insert the PHI node for the induction variable in the // specified loop. BasicBlock *Header = L->getHeader(); - BasicBlock *Preheader = L->getLoopPreheader(); PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin()); InsertedValues.insert(PN); - PN->addIncoming(Constant::getNullValue(Ty), Preheader); - pred_iterator HPI = pred_begin(Header); - assert(HPI != pred_end(Header) && "Loop with zero preds???"); - if (!L->contains(*HPI)) ++HPI; - assert(HPI != pred_end(Header) && L->contains(*HPI) && - "No backedge in loop?"); - - // Insert a unit add instruction right before the terminator corresponding - // to the back-edge. Constant *One = ConstantInt::get(Ty, 1); - Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next", - (*HPI)->getTerminator()); - InsertedValues.insert(Add); - - pred_iterator PI = pred_begin(Header); - if (*PI == Preheader) - ++PI; - PN->addIncoming(Add, *PI); - return PN; + for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header); + HPI != HPE; ++HPI) + if (L->contains(*HPI)) { + // Insert a unit add instruction right before the terminator corresponding + // to the back-edge. + Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next", + (*HPI)->getTerminator()); + InsertedValues.insert(Add); + PN->addIncoming(Add, *HPI); + } else { + PN->addIncoming(Constant::getNullValue(Ty), *HPI); + } } // {0,+,F} --> {0,+,1} * F @@ -563,19 +717,19 @@ Value *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { // folders, then expandCodeFor the closed form. This allows the folders to // simplify the expression without having to build a bunch of special code // into this folder. - const SCEV* IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV. + const SCEV *IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV. // Promote S up to the canonical IV type, if the cast is foldable. - const SCEV* NewS = S; - const SCEV* Ext = SE.getNoopOrAnyExtend(S, I->getType()); + const SCEV *NewS = S; + const SCEV *Ext = SE.getNoopOrAnyExtend(S, I->getType()); if (isa<SCEVAddRecExpr>(Ext)) NewS = Ext; - const SCEV* V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); + const SCEV *V = cast<SCEVAddRecExpr>(NewS)->evaluateAtIteration(IH, SE); //cerr << "Evaluated: " << *this << "\n to: " << *V << "\n"; // Truncate the result down to the original type, if needed. - const SCEV* T = SE.getTruncateOrNoop(V, Ty); + const SCEV *T = SE.getTruncateOrNoop(V, Ty); return expand(T); } @@ -607,9 +761,15 @@ Value *SCEVExpander::visitSignExtendExpr(const SCEVSignExtendExpr *S) { } Value *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { - const Type *Ty = SE.getEffectiveSCEVType(S->getType()); - Value *LHS = expandCodeFor(S->getOperand(0), Ty); - for (unsigned i = 1; i < S->getNumOperands(); ++i) { + Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); + const Type *Ty = LHS->getType(); + for (int i = S->getNumOperands()-2; i >= 0; --i) { + // In the case of mixed integer and pointer types, do the + // rest of the comparisons as integer. + if (S->getOperand(i)->getType() != Ty) { + Ty = SE.getEffectiveSCEVType(Ty); + LHS = InsertNoopCastOfTo(LHS, Ty); + } Value *RHS = expandCodeFor(S->getOperand(i), Ty); Value *ICmp = Builder.CreateICmpSGT(LHS, RHS, "tmp"); InsertedValues.insert(ICmp); @@ -617,13 +777,23 @@ Value *SCEVExpander::visitSMaxExpr(const SCEVSMaxExpr *S) { InsertedValues.insert(Sel); LHS = Sel; } + // In the case of mixed integer and pointer types, cast the + // final result back to the pointer type. + if (LHS->getType() != S->getType()) + LHS = InsertNoopCastOfTo(LHS, S->getType()); return LHS; } Value *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { - const Type *Ty = SE.getEffectiveSCEVType(S->getType()); - Value *LHS = expandCodeFor(S->getOperand(0), Ty); - for (unsigned i = 1; i < S->getNumOperands(); ++i) { + Value *LHS = expand(S->getOperand(S->getNumOperands()-1)); + const Type *Ty = LHS->getType(); + for (int i = S->getNumOperands()-2; i >= 0; --i) { + // In the case of mixed integer and pointer types, do the + // rest of the comparisons as integer. + if (S->getOperand(i)->getType() != Ty) { + Ty = SE.getEffectiveSCEVType(Ty); + LHS = InsertNoopCastOfTo(LHS, Ty); + } Value *RHS = expandCodeFor(S->getOperand(i), Ty); Value *ICmp = Builder.CreateICmpUGT(LHS, RHS, "tmp"); InsertedValues.insert(ICmp); @@ -631,10 +801,22 @@ Value *SCEVExpander::visitUMaxExpr(const SCEVUMaxExpr *S) { InsertedValues.insert(Sel); LHS = Sel; } + // In the case of mixed integer and pointer types, cast the + // final result back to the pointer type. + if (LHS->getType() != S->getType()) + LHS = InsertNoopCastOfTo(LHS, S->getType()); return LHS; } -Value *SCEVExpander::expandCodeFor(const SCEV* SH, const Type *Ty) { +Value *SCEVExpander::visitFieldOffsetExpr(const SCEVFieldOffsetExpr *S) { + return ConstantExpr::getOffsetOf(S->getStructType(), S->getFieldNo()); +} + +Value *SCEVExpander::visitAllocSizeExpr(const SCEVAllocSizeExpr *S) { + return ConstantExpr::getSizeOf(S->getAllocType()); +} + +Value *SCEVExpander::expandCodeFor(const SCEV *SH, const Type *Ty) { // Expand the code for this SCEV. Value *V = expand(SH); if (Ty) { @@ -695,7 +877,7 @@ Value * SCEVExpander::getOrInsertCanonicalInductionVariable(const Loop *L, const Type *Ty) { assert(Ty->isInteger() && "Can only insert integer induction variables!"); - const SCEV* H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty), + const SCEV *H = SE.getAddRecExpr(SE.getIntegerSCEV(0, Ty), SE.getIntegerSCEV(1, Ty), L); BasicBlock *SaveInsertBB = Builder.GetInsertBlock(); BasicBlock::iterator SaveInsertPt = Builder.GetInsertPoint(); |
