// There are several aspects to this library. First is the representation of
// scalar expressions, which are represented as subclasses of the SCEV class.
// These classes are used to represent certain types of subexpressions that we
-// can handle. These classes are reference counted, managed by the SCEVHandle
+// can handle. These classes are reference counted, managed by the const SCEV*
// class. We only create one SCEV of a particular shape, so pointer-comparisons
// for equality are legal.
//
#include "llvm/Support/ConstantRange.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/InstIterator.h"
-#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/Statistic.h"
return false;
}
-SCEVCouldNotCompute::SCEVCouldNotCompute(const ScalarEvolution* p) :
- SCEV(scCouldNotCompute, p) {}
-SCEVCouldNotCompute::~SCEVCouldNotCompute() {}
+bool SCEV::isAllOnesValue() const {
+ if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(this))
+ return SC->getValue()->isAllOnesValue();
+ return false;
+}
+
+SCEVCouldNotCompute::SCEVCouldNotCompute() :
+ SCEV(scCouldNotCompute) {}
bool SCEVCouldNotCompute::isLoopInvariant(const Loop *L) const {
assert(0 && "Attempt to use a SCEVCouldNotCompute object!");
return false;
}
-SCEVHandle SCEVCouldNotCompute::
-replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
+const SCEV* SCEVCouldNotCompute::
+replaceSymbolicValuesWithConcrete(const SCEV* Sym,
+ const SCEV* Conc,
ScalarEvolution &SE) const {
return this;
}
// SCEVConstants - Only allow the creation of one SCEVConstant for any
-// particular value. Don't use a SCEVHandle here, or else the object will
+// particular value. Don't use a const SCEV* here, or else the object will
// never be deleted!
-SCEVHandle ScalarEvolution::getConstant(ConstantInt *V) {
+const SCEV* ScalarEvolution::getConstant(ConstantInt *V) {
SCEVConstant *&R = SCEVConstants[V];
- if (R == 0) R = new SCEVConstant(V, this);
+ if (R == 0) R = new SCEVConstant(V);
return R;
}
-SCEVHandle ScalarEvolution::getConstant(const APInt& Val) {
+const SCEV* ScalarEvolution::getConstant(const APInt& Val) {
return getConstant(ConstantInt::get(Val));
}
-SCEVHandle
+const SCEV*
ScalarEvolution::getConstant(const Type *Ty, uint64_t V, bool isSigned) {
return getConstant(ConstantInt::get(cast<IntegerType>(Ty), V, isSigned));
}
}
SCEVCastExpr::SCEVCastExpr(unsigned SCEVTy,
- const SCEVHandle &op, const Type *ty,
- const ScalarEvolution* p)
- : SCEV(SCEVTy, p), Op(op), Ty(ty) {}
-
-SCEVCastExpr::~SCEVCastExpr() {}
+ const SCEV* op, const Type *ty)
+ : SCEV(SCEVTy), Op(op), Ty(ty) {}
bool SCEVCastExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
return Op->dominates(BB, DT);
}
// SCEVTruncates - Only allow the creation of one SCEVTruncateExpr for any
-// particular input. Don't use a SCEVHandle here, or else the object will
+// particular input. Don't use a const SCEV* here, or else the object will
// never be deleted!
-SCEVTruncateExpr::SCEVTruncateExpr(const SCEVHandle &op, const Type *ty,
- const ScalarEvolution* p)
- : SCEVCastExpr(scTruncate, op, ty, p) {
+SCEVTruncateExpr::SCEVTruncateExpr(const SCEV* op, const Type *ty)
+ : SCEVCastExpr(scTruncate, op, ty) {
assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
(Ty->isInteger() || isa<PointerType>(Ty)) &&
"Cannot truncate non-integer value!");
}
// SCEVZeroExtends - Only allow the creation of one SCEVZeroExtendExpr for any
-// particular input. Don't use a SCEVHandle here, or else the object will never
+// particular input. Don't use a const SCEV* here, or else the object will never
// be deleted!
-SCEVZeroExtendExpr::SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty,
- const ScalarEvolution* p)
- : SCEVCastExpr(scZeroExtend, op, ty, p) {
+SCEVZeroExtendExpr::SCEVZeroExtendExpr(const SCEV* op, const Type *ty)
+ : SCEVCastExpr(scZeroExtend, op, ty) {
assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
(Ty->isInteger() || isa<PointerType>(Ty)) &&
"Cannot zero extend non-integer value!");
}
// SCEVSignExtends - Only allow the creation of one SCEVSignExtendExpr for any
-// particular input. Don't use a SCEVHandle here, or else the object will never
+// particular input. Don't use a const SCEV* here, or else the object will never
// be deleted!
-SCEVSignExtendExpr::SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty,
- const ScalarEvolution* p)
- : SCEVCastExpr(scSignExtend, op, ty, p) {
+SCEVSignExtendExpr::SCEVSignExtendExpr(const SCEV* op, const Type *ty)
+ : SCEVCastExpr(scSignExtend, op, ty) {
assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
(Ty->isInteger() || isa<PointerType>(Ty)) &&
"Cannot sign extend non-integer value!");
}
// SCEVCommExprs - Only allow the creation of one SCEVCommutativeExpr for any
-// particular input. Don't use a SCEVHandle here, or else the object will never
+// particular input. Don't use a const SCEV* here, or else the object will never
// be deleted!
void SCEVCommutativeExpr::print(raw_ostream &OS) const {
OS << ")";
}
-SCEVHandle SCEVCommutativeExpr::
-replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
+const SCEV* SCEVCommutativeExpr::
+replaceSymbolicValuesWithConcrete(const SCEV* Sym,
+ const SCEV* Conc,
ScalarEvolution &SE) const {
for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
- SCEVHandle H =
+ const SCEV* H =
getOperand(i)->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
if (H != getOperand(i)) {
- SmallVector<SCEVHandle, 8> NewOps;
+ SmallVector<const SCEV*, 8> NewOps;
NewOps.reserve(getNumOperands());
for (unsigned j = 0; j != i; ++j)
NewOps.push_back(getOperand(j));
// SCEVUDivs - Only allow the creation of one SCEVUDivExpr for any particular
-// input. Don't use a SCEVHandle here, or else the object will never be
+// input. Don't use a const SCEV* here, or else the object will never be
// deleted!
bool SCEVUDivExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
}
// SCEVAddRecExprs - Only allow the creation of one SCEVAddRecExpr for any
-// particular input. Don't use a SCEVHandle here, or else the object will never
+// particular input. Don't use a const SCEV* here, or else the object will never
// be deleted!
-SCEVHandle SCEVAddRecExpr::
-replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
+const SCEV* SCEVAddRecExpr::
+replaceSymbolicValuesWithConcrete(const SCEV* Sym,
+ const SCEV* Conc,
ScalarEvolution &SE) const {
for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
- SCEVHandle H =
+ const SCEV* H =
getOperand(i)->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
if (H != getOperand(i)) {
- SmallVector<SCEVHandle, 8> NewOps;
+ SmallVector<const SCEV*, 8> NewOps;
NewOps.reserve(getNumOperands());
for (unsigned j = 0; j != i; ++j)
NewOps.push_back(getOperand(j));
}
// SCEVUnknowns - Only allow the creation of one SCEVUnknown for any particular
-// value. Don't use a SCEVHandle here, or else the object will never be
+// value. Don't use a const SCEV* here, or else the object will never be
// deleted!
bool SCEVUnknown::isLoopInvariant(const Loop *L) const {
/// this to depend on where the addresses of various SCEV objects happened to
/// land in memory.
///
-static void GroupByComplexity(SmallVectorImpl<SCEVHandle> &Ops,
+static void GroupByComplexity(SmallVectorImpl<const SCEV*> &Ops,
LoopInfo *LI) {
if (Ops.size() < 2) return; // Noop
if (Ops.size() == 2) {
/// BinomialCoefficient - Compute BC(It, K). The result has width W.
/// Assume, K > 0.
-static SCEVHandle BinomialCoefficient(SCEVHandle It, unsigned K,
+static const SCEV* BinomialCoefficient(const SCEV* It, unsigned K,
ScalarEvolution &SE,
const Type* ResultTy) {
// Handle the simplest case efficiently.
// Calculate the product, at width T+W
const IntegerType *CalculationTy = IntegerType::get(CalculationBits);
- SCEVHandle Dividend = SE.getTruncateOrZeroExtend(It, CalculationTy);
+ const SCEV* Dividend = SE.getTruncateOrZeroExtend(It, CalculationTy);
for (unsigned i = 1; i != K; ++i) {
- SCEVHandle S = SE.getMinusSCEV(It, SE.getIntegerSCEV(i, It->getType()));
+ const SCEV* S = SE.getMinusSCEV(It, SE.getIntegerSCEV(i, It->getType()));
Dividend = SE.getMulExpr(Dividend,
SE.getTruncateOrZeroExtend(S, CalculationTy));
}
// Divide by 2^T
- SCEVHandle DivResult = SE.getUDivExpr(Dividend, SE.getConstant(DivFactor));
+ const SCEV* DivResult = SE.getUDivExpr(Dividend, SE.getConstant(DivFactor));
// Truncate the result, and divide by K! / 2^T.
///
/// where BC(It, k) stands for binomial coefficient.
///
-SCEVHandle SCEVAddRecExpr::evaluateAtIteration(SCEVHandle It,
+const SCEV* SCEVAddRecExpr::evaluateAtIteration(const SCEV* It,
ScalarEvolution &SE) const {
- SCEVHandle Result = getStart();
+ const SCEV* Result = getStart();
for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
// The computation is correct in the face of overflow provided that the
// multiplication is performed _after_ the evaluation of the binomial
// coefficient.
- SCEVHandle Coeff = BinomialCoefficient(It, i, SE, getType());
+ const SCEV* Coeff = BinomialCoefficient(It, i, SE, getType());
if (isa<SCEVCouldNotCompute>(Coeff))
return Coeff;
// SCEV Expression folder implementations
//===----------------------------------------------------------------------===//
-SCEVHandle ScalarEvolution::getTruncateExpr(const SCEVHandle &Op,
+const SCEV* ScalarEvolution::getTruncateExpr(const SCEV* Op,
const Type *Ty) {
assert(getTypeSizeInBits(Op->getType()) > getTypeSizeInBits(Ty) &&
"This is not a truncating conversion!");
Ty = getEffectiveSCEVType(Ty);
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op))
- return getUnknown(
- ConstantExpr::getTrunc(SC->getValue(), Ty));
+ return getConstant(
+ cast<ConstantInt>(ConstantExpr::getTrunc(SC->getValue(), Ty)));
// trunc(trunc(x)) --> trunc(x)
if (const SCEVTruncateExpr *ST = dyn_cast<SCEVTruncateExpr>(Op))
// If the input value is a chrec scev, truncate the chrec's operands.
if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Op)) {
- SmallVector<SCEVHandle, 4> Operands;
+ SmallVector<const SCEV*, 4> Operands;
for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i)
Operands.push_back(getTruncateExpr(AddRec->getOperand(i), Ty));
return getAddRecExpr(Operands, AddRec->getLoop());
}
SCEVTruncateExpr *&Result = SCEVTruncates[std::make_pair(Op, Ty)];
- if (Result == 0) Result = new SCEVTruncateExpr(Op, Ty, this);
+ if (Result == 0) Result = new SCEVTruncateExpr(Op, Ty);
return Result;
}
-SCEVHandle ScalarEvolution::getZeroExtendExpr(const SCEVHandle &Op,
+const SCEV* ScalarEvolution::getZeroExtendExpr(const SCEV* Op,
const Type *Ty) {
assert(getTypeSizeInBits(Op->getType()) < getTypeSizeInBits(Ty) &&
"This is not an extending conversion!");
const Type *IntTy = getEffectiveSCEVType(Ty);
Constant *C = ConstantExpr::getZExt(SC->getValue(), IntTy);
if (IntTy != Ty) C = ConstantExpr::getIntToPtr(C, Ty);
- return getUnknown(C);
+ return getConstant(cast<ConstantInt>(C));
}
// zext(zext(x)) --> zext(x)
// in infinite recursion. In the later case, the analysis code will
// cope with a conservative value, and it will take care to purge
// that value once it has finished.
- SCEVHandle MaxBECount = getMaxBackedgeTakenCount(AR->getLoop());
+ const SCEV* MaxBECount = getMaxBackedgeTakenCount(AR->getLoop());
if (!isa<SCEVCouldNotCompute>(MaxBECount)) {
// Manually compute the final value for AR, checking for
// overflow.
- SCEVHandle Start = AR->getStart();
- SCEVHandle Step = AR->getStepRecurrence(*this);
+ const SCEV* Start = AR->getStart();
+ const SCEV* Step = AR->getStepRecurrence(*this);
// Check whether the backedge-taken count can be losslessly casted to
// the addrec's type. The count is always unsigned.
- SCEVHandle CastedMaxBECount =
+ const SCEV* CastedMaxBECount =
getTruncateOrZeroExtend(MaxBECount, Start->getType());
- SCEVHandle RecastedMaxBECount =
+ const SCEV* RecastedMaxBECount =
getTruncateOrZeroExtend(CastedMaxBECount, MaxBECount->getType());
if (MaxBECount == RecastedMaxBECount) {
const Type *WideTy =
IntegerType::get(getTypeSizeInBits(Start->getType()) * 2);
// Check whether Start+Step*MaxBECount has no unsigned overflow.
- SCEVHandle ZMul =
+ const SCEV* ZMul =
getMulExpr(CastedMaxBECount,
getTruncateOrZeroExtend(Step, Start->getType()));
- SCEVHandle Add = getAddExpr(Start, ZMul);
- SCEVHandle OperandExtendedAdd =
+ const SCEV* Add = getAddExpr(Start, ZMul);
+ const SCEV* OperandExtendedAdd =
getAddExpr(getZeroExtendExpr(Start, WideTy),
getMulExpr(getZeroExtendExpr(CastedMaxBECount, WideTy),
getZeroExtendExpr(Step, WideTy)));
// Similar to above, only this time treat the step value as signed.
// This covers loops that count down.
- SCEVHandle SMul =
+ const SCEV* SMul =
getMulExpr(CastedMaxBECount,
getTruncateOrSignExtend(Step, Start->getType()));
Add = getAddExpr(Start, SMul);
}
SCEVZeroExtendExpr *&Result = SCEVZeroExtends[std::make_pair(Op, Ty)];
- if (Result == 0) Result = new SCEVZeroExtendExpr(Op, Ty, this);
+ if (Result == 0) Result = new SCEVZeroExtendExpr(Op, Ty);
return Result;
}
-SCEVHandle ScalarEvolution::getSignExtendExpr(const SCEVHandle &Op,
+const SCEV* ScalarEvolution::getSignExtendExpr(const SCEV* Op,
const Type *Ty) {
assert(getTypeSizeInBits(Op->getType()) < getTypeSizeInBits(Ty) &&
"This is not an extending conversion!");
const Type *IntTy = getEffectiveSCEVType(Ty);
Constant *C = ConstantExpr::getSExt(SC->getValue(), IntTy);
if (IntTy != Ty) C = ConstantExpr::getIntToPtr(C, Ty);
- return getUnknown(C);
+ return getConstant(cast<ConstantInt>(C));
}
// sext(sext(x)) --> sext(x)
// in infinite recursion. In the later case, the analysis code will
// cope with a conservative value, and it will take care to purge
// that value once it has finished.
- SCEVHandle MaxBECount = getMaxBackedgeTakenCount(AR->getLoop());
+ const SCEV* MaxBECount = getMaxBackedgeTakenCount(AR->getLoop());
if (!isa<SCEVCouldNotCompute>(MaxBECount)) {
// Manually compute the final value for AR, checking for
// overflow.
- SCEVHandle Start = AR->getStart();
- SCEVHandle Step = AR->getStepRecurrence(*this);
+ const SCEV* Start = AR->getStart();
+ const SCEV* Step = AR->getStepRecurrence(*this);
// Check whether the backedge-taken count can be losslessly casted to
// the addrec's type. The count is always unsigned.
- SCEVHandle CastedMaxBECount =
+ const SCEV* CastedMaxBECount =
getTruncateOrZeroExtend(MaxBECount, Start->getType());
- SCEVHandle RecastedMaxBECount =
+ const SCEV* RecastedMaxBECount =
getTruncateOrZeroExtend(CastedMaxBECount, MaxBECount->getType());
if (MaxBECount == RecastedMaxBECount) {
const Type *WideTy =
IntegerType::get(getTypeSizeInBits(Start->getType()) * 2);
// Check whether Start+Step*MaxBECount has no signed overflow.
- SCEVHandle SMul =
+ const SCEV* SMul =
getMulExpr(CastedMaxBECount,
getTruncateOrSignExtend(Step, Start->getType()));
- SCEVHandle Add = getAddExpr(Start, SMul);
- SCEVHandle OperandExtendedAdd =
+ const SCEV* Add = getAddExpr(Start, SMul);
+ const SCEV* OperandExtendedAdd =
getAddExpr(getSignExtendExpr(Start, WideTy),
getMulExpr(getZeroExtendExpr(CastedMaxBECount, WideTy),
getSignExtendExpr(Step, WideTy)));
}
SCEVSignExtendExpr *&Result = SCEVSignExtends[std::make_pair(Op, Ty)];
- if (Result == 0) Result = new SCEVSignExtendExpr(Op, Ty, this);
+ if (Result == 0) Result = new SCEVSignExtendExpr(Op, Ty);
return Result;
}
/// getAnyExtendExpr - Return a SCEV for the given operand extended with
/// unspecified bits out to the given type.
///
-SCEVHandle ScalarEvolution::getAnyExtendExpr(const SCEVHandle &Op,
+const SCEV* ScalarEvolution::getAnyExtendExpr(const SCEV* Op,
const Type *Ty) {
assert(getTypeSizeInBits(Op->getType()) < getTypeSizeInBits(Ty) &&
"This is not an extending conversion!");
// Peel off a truncate cast.
if (const SCEVTruncateExpr *T = dyn_cast<SCEVTruncateExpr>(Op)) {
- SCEVHandle NewOp = T->getOperand();
+ const SCEV* NewOp = T->getOperand();
if (getTypeSizeInBits(NewOp->getType()) < getTypeSizeInBits(Ty))
return getAnyExtendExpr(NewOp, Ty);
return getTruncateOrNoop(NewOp, Ty);
}
// Next try a zext cast. If the cast is folded, use it.
- SCEVHandle ZExt = getZeroExtendExpr(Op, Ty);
+ const SCEV* ZExt = getZeroExtendExpr(Op, Ty);
if (!isa<SCEVZeroExtendExpr>(ZExt))
return ZExt;
// Next try a sext cast. If the cast is folded, use it.
- SCEVHandle SExt = getSignExtendExpr(Op, Ty);
+ const SCEV* SExt = getSignExtendExpr(Op, Ty);
if (!isa<SCEVSignExtendExpr>(SExt))
return SExt;
/// is also used as a check to avoid infinite recursion.
///
static bool
-CollectAddOperandsWithScales(DenseMap<SCEVHandle, APInt> &M,
- SmallVector<SCEVHandle, 8> &NewOps,
+CollectAddOperandsWithScales(DenseMap<const SCEV*, APInt> &M,
+ SmallVector<const SCEV*, 8> &NewOps,
APInt &AccumulatedConstant,
- const SmallVectorImpl<SCEVHandle> &Ops,
+ const SmallVectorImpl<const SCEV*> &Ops,
const APInt &Scale,
ScalarEvolution &SE) {
bool Interesting = false;
} else {
// A multiplication of a constant with some other value. Update
// the map.
- SmallVector<SCEVHandle, 4> MulOps(Mul->op_begin()+1, Mul->op_end());
- SCEVHandle Key = SE.getMulExpr(MulOps);
- std::pair<DenseMap<SCEVHandle, APInt>::iterator, bool> Pair =
+ SmallVector<const SCEV*, 4> MulOps(Mul->op_begin()+1, Mul->op_end());
+ const SCEV* Key = SE.getMulExpr(MulOps);
+ std::pair<DenseMap<const SCEV*, APInt>::iterator, bool> Pair =
M.insert(std::make_pair(Key, APInt()));
if (Pair.second) {
Pair.first->second = NewScale;
AccumulatedConstant += Scale * C->getValue()->getValue();
} else {
// An ordinary operand. Update the map.
- std::pair<DenseMap<SCEVHandle, APInt>::iterator, bool> Pair =
+ std::pair<DenseMap<const SCEV*, APInt>::iterator, bool> Pair =
M.insert(std::make_pair(Ops[i], APInt()));
if (Pair.second) {
Pair.first->second = Scale;
/// getAddExpr - Get a canonical add expression, or something simpler if
/// possible.
-SCEVHandle ScalarEvolution::getAddExpr(SmallVectorImpl<SCEVHandle> &Ops) {
+const SCEV* ScalarEvolution::getAddExpr(SmallVectorImpl<const SCEV*> &Ops) {
assert(!Ops.empty() && "Cannot get empty add!");
if (Ops.size() == 1) return Ops[0];
#ifndef NDEBUG
if (Ops[i] == Ops[i+1]) { // X + Y + Y --> X + Y*2
// Found a match, merge the two values into a multiply, and add any
// remaining values to the result.
- SCEVHandle Two = getIntegerSCEV(2, Ty);
- SCEVHandle Mul = getMulExpr(Ops[i], Two);
+ const SCEV* Two = getIntegerSCEV(2, Ty);
+ const SCEV* Mul = getMulExpr(Ops[i], Two);
if (Ops.size() == 2)
return Mul;
Ops.erase(Ops.begin()+i, Ops.begin()+i+2);
const SCEVTruncateExpr *Trunc = cast<SCEVTruncateExpr>(Ops[Idx]);
const Type *DstType = Trunc->getType();
const Type *SrcType = Trunc->getOperand()->getType();
- SmallVector<SCEVHandle, 8> LargeOps;
+ SmallVector<const SCEV*, 8> LargeOps;
bool Ok = true;
// Check all the operands to see if they can be represented in the
// source type of the truncate.
// is much more likely to be foldable here.
LargeOps.push_back(getSignExtendExpr(C, SrcType));
} else if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(Ops[i])) {
- SmallVector<SCEVHandle, 8> LargeMulOps;
+ SmallVector<const SCEV*, 8> LargeMulOps;
for (unsigned j = 0, f = M->getNumOperands(); j != f && Ok; ++j) {
if (const SCEVTruncateExpr *T =
dyn_cast<SCEVTruncateExpr>(M->getOperand(j))) {
}
if (Ok) {
// Evaluate the expression in the larger type.
- SCEVHandle Fold = getAddExpr(LargeOps);
+ const SCEV* Fold = getAddExpr(LargeOps);
// If it folds to something simple, use it. Otherwise, don't.
if (isa<SCEVConstant>(Fold) || isa<SCEVUnknown>(Fold))
return getTruncateExpr(Fold, DstType);
// operands multiplied by constant values.
if (Idx < Ops.size() && isa<SCEVMulExpr>(Ops[Idx])) {
uint64_t BitWidth = getTypeSizeInBits(Ty);
- DenseMap<SCEVHandle, APInt> M;
- SmallVector<SCEVHandle, 8> NewOps;
+ DenseMap<const SCEV*, APInt> M;
+ SmallVector<const SCEV*, 8> NewOps;
APInt AccumulatedConstant(BitWidth, 0);
if (CollectAddOperandsWithScales(M, NewOps, AccumulatedConstant,
Ops, APInt(BitWidth, 1), *this)) {
// Some interesting folding opportunity is present, so its worthwhile to
// re-generate the operands list. Group the operands by constant scale,
// to avoid multiplying by the same constant scale multiple times.
- std::map<APInt, SmallVector<SCEVHandle, 4>, APIntCompare> MulOpLists;
- for (SmallVector<SCEVHandle, 8>::iterator I = NewOps.begin(),
+ std::map<APInt, SmallVector<const SCEV*, 4>, APIntCompare> MulOpLists;
+ for (SmallVector<const SCEV*, 8>::iterator I = NewOps.begin(),
E = NewOps.end(); I != E; ++I)
MulOpLists[M.find(*I)->second].push_back(*I);
// Re-generate the operands list.
Ops.clear();
if (AccumulatedConstant != 0)
Ops.push_back(getConstant(AccumulatedConstant));
- for (std::map<APInt, SmallVector<SCEVHandle, 4>, APIntCompare>::iterator I =
+ for (std::map<APInt, SmallVector<const SCEV*, 4>, APIntCompare>::iterator I =
MulOpLists.begin(), E = MulOpLists.end(); I != E; ++I)
if (I->first != 0)
Ops.push_back(getMulExpr(getConstant(I->first), getAddExpr(I->second)));
for (unsigned AddOp = 0, e = Ops.size(); AddOp != e; ++AddOp)
if (MulOpSCEV == Ops[AddOp] && !isa<SCEVConstant>(Ops[AddOp])) {
// Fold W + X + (X * Y * Z) --> W + (X * ((Y*Z)+1))
- SCEVHandle InnerMul = Mul->getOperand(MulOp == 0);
+ const SCEV* InnerMul = Mul->getOperand(MulOp == 0);
if (Mul->getNumOperands() != 2) {
// If the multiply has more than two operands, we must get the
// Y*Z term.
- SmallVector<SCEVHandle, 4> MulOps(Mul->op_begin(), Mul->op_end());
+ SmallVector<const SCEV*, 4> MulOps(Mul->op_begin(), Mul->op_end());
MulOps.erase(MulOps.begin()+MulOp);
InnerMul = getMulExpr(MulOps);
}
- SCEVHandle One = getIntegerSCEV(1, Ty);
- SCEVHandle AddOne = getAddExpr(InnerMul, One);
- SCEVHandle OuterMul = getMulExpr(AddOne, Ops[AddOp]);
+ const SCEV* One = getIntegerSCEV(1, Ty);
+ const SCEV* AddOne = getAddExpr(InnerMul, One);
+ const SCEV* OuterMul = getMulExpr(AddOne, Ops[AddOp]);
if (Ops.size() == 2) return OuterMul;
if (AddOp < Idx) {
Ops.erase(Ops.begin()+AddOp);
OMulOp != e; ++OMulOp)
if (OtherMul->getOperand(OMulOp) == MulOpSCEV) {
// Fold X + (A*B*C) + (A*D*E) --> X + (A*(B*C+D*E))
- SCEVHandle InnerMul1 = Mul->getOperand(MulOp == 0);
+ const SCEV* InnerMul1 = Mul->getOperand(MulOp == 0);
if (Mul->getNumOperands() != 2) {
- SmallVector<SCEVHandle, 4> MulOps(Mul->op_begin(), Mul->op_end());
+ SmallVector<const SCEV*, 4> MulOps(Mul->op_begin(), Mul->op_end());
MulOps.erase(MulOps.begin()+MulOp);
InnerMul1 = getMulExpr(MulOps);
}
- SCEVHandle InnerMul2 = OtherMul->getOperand(OMulOp == 0);
+ const SCEV* InnerMul2 = OtherMul->getOperand(OMulOp == 0);
if (OtherMul->getNumOperands() != 2) {
- SmallVector<SCEVHandle, 4> MulOps(OtherMul->op_begin(),
+ SmallVector<const SCEV*, 4> MulOps(OtherMul->op_begin(),
OtherMul->op_end());
MulOps.erase(MulOps.begin()+OMulOp);
InnerMul2 = getMulExpr(MulOps);
}
- SCEVHandle InnerMulSum = getAddExpr(InnerMul1,InnerMul2);
- SCEVHandle OuterMul = getMulExpr(MulOpSCEV, InnerMulSum);
+ const SCEV* InnerMulSum = getAddExpr(InnerMul1,InnerMul2);
+ const SCEV* OuterMul = getMulExpr(MulOpSCEV, InnerMulSum);
if (Ops.size() == 2) return OuterMul;
Ops.erase(Ops.begin()+Idx);
Ops.erase(Ops.begin()+OtherMulIdx-1);
for (; Idx < Ops.size() && isa<SCEVAddRecExpr>(Ops[Idx]); ++Idx) {
// Scan all of the other operands to this add and add them to the vector if
// they are loop invariant w.r.t. the recurrence.
- SmallVector<SCEVHandle, 8> LIOps;
+ SmallVector<const SCEV*, 8> LIOps;
const SCEVAddRecExpr *AddRec = cast<SCEVAddRecExpr>(Ops[Idx]);
for (unsigned i = 0, e = Ops.size(); i != e; ++i)
if (Ops[i]->isLoopInvariant(AddRec->getLoop())) {
// NLI + LI + {Start,+,Step} --> NLI + {LI+Start,+,Step}
LIOps.push_back(AddRec->getStart());
- SmallVector<SCEVHandle, 4> AddRecOps(AddRec->op_begin(),
+ SmallVector<const SCEV*, 4> AddRecOps(AddRec->op_begin(),
AddRec->op_end());
AddRecOps[0] = getAddExpr(LIOps);
- SCEVHandle NewRec = getAddRecExpr(AddRecOps, AddRec->getLoop());
+ const SCEV* NewRec = getAddRecExpr(AddRecOps, AddRec->getLoop());
// If all of the other operands were loop invariant, we are done.
if (Ops.size() == 1) return NewRec;
const SCEVAddRecExpr *OtherAddRec = cast<SCEVAddRecExpr>(Ops[OtherIdx]);
if (AddRec->getLoop() == OtherAddRec->getLoop()) {
// Other + {A,+,B} + {C,+,D} --> Other + {A+C,+,B+D}
- SmallVector<SCEVHandle, 4> NewOps(AddRec->op_begin(), AddRec->op_end());
+ SmallVector<const SCEV*, 4> NewOps(AddRec->op_begin(), AddRec->op_end());
for (unsigned i = 0, e = OtherAddRec->getNumOperands(); i != e; ++i) {
if (i >= NewOps.size()) {
NewOps.insert(NewOps.end(), OtherAddRec->op_begin()+i,
}
NewOps[i] = getAddExpr(NewOps[i], OtherAddRec->getOperand(i));
}
- SCEVHandle NewAddRec = getAddRecExpr(NewOps, AddRec->getLoop());
+ const SCEV* NewAddRec = getAddRecExpr(NewOps, AddRec->getLoop());
if (Ops.size() == 2) return NewAddRec;
std::vector<const SCEV*> SCEVOps(Ops.begin(), Ops.end());
SCEVCommutativeExpr *&Result = SCEVCommExprs[std::make_pair(scAddExpr,
SCEVOps)];
- if (Result == 0) Result = new SCEVAddExpr(Ops, this);
+ if (Result == 0) Result = new SCEVAddExpr(Ops);
return Result;
}
/// getMulExpr - Get a canonical multiply expression, or something simpler if
/// possible.
-SCEVHandle ScalarEvolution::getMulExpr(SmallVectorImpl<SCEVHandle> &Ops) {
+const SCEV* ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV*> &Ops) {
assert(!Ops.empty() && "Cannot get empty mul!");
#ifndef NDEBUG
for (unsigned i = 1, e = Ops.size(); i != e; ++i)
for (; Idx < Ops.size() && isa<SCEVAddRecExpr>(Ops[Idx]); ++Idx) {
// Scan all of the other operands to this mul and add them to the vector if
// they are loop invariant w.r.t. the recurrence.
- SmallVector<SCEVHandle, 8> LIOps;
+ SmallVector<const SCEV*, 8> LIOps;
const SCEVAddRecExpr *AddRec = cast<SCEVAddRecExpr>(Ops[Idx]);
for (unsigned i = 0, e = Ops.size(); i != e; ++i)
if (Ops[i]->isLoopInvariant(AddRec->getLoop())) {
// If we found some loop invariants, fold them into the recurrence.
if (!LIOps.empty()) {
// NLI * LI * {Start,+,Step} --> NLI * {LI*Start,+,LI*Step}
- SmallVector<SCEVHandle, 4> NewOps;
+ SmallVector<const SCEV*, 4> NewOps;
NewOps.reserve(AddRec->getNumOperands());
if (LIOps.size() == 1) {
const SCEV *Scale = LIOps[0];
NewOps.push_back(getMulExpr(Scale, AddRec->getOperand(i)));
} else {
for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i) {
- SmallVector<SCEVHandle, 4> MulOps(LIOps.begin(), LIOps.end());
+ SmallVector<const SCEV*, 4> MulOps(LIOps.begin(), LIOps.end());
MulOps.push_back(AddRec->getOperand(i));
NewOps.push_back(getMulExpr(MulOps));
}
}
- SCEVHandle NewRec = getAddRecExpr(NewOps, AddRec->getLoop());
+ const SCEV* NewRec = getAddRecExpr(NewOps, AddRec->getLoop());
// If all of the other operands were loop invariant, we are done.
if (Ops.size() == 1) return NewRec;
if (AddRec->getLoop() == OtherAddRec->getLoop()) {
// F * G --> {A,+,B} * {C,+,D} --> {A*C,+,F*D + G*B + B*D}
const SCEVAddRecExpr *F = AddRec, *G = OtherAddRec;
- SCEVHandle NewStart = getMulExpr(F->getStart(),
+ const SCEV* NewStart = getMulExpr(F->getStart(),
G->getStart());
- SCEVHandle B = F->getStepRecurrence(*this);
- SCEVHandle D = G->getStepRecurrence(*this);
- SCEVHandle NewStep = getAddExpr(getMulExpr(F, D),
+ const SCEV* B = F->getStepRecurrence(*this);
+ const SCEV* D = G->getStepRecurrence(*this);
+ const SCEV* NewStep = getAddExpr(getMulExpr(F, D),
getMulExpr(G, B),
getMulExpr(B, D));
- SCEVHandle NewAddRec = getAddRecExpr(NewStart, NewStep,
+ const SCEV* NewAddRec = getAddRecExpr(NewStart, NewStep,
F->getLoop());
if (Ops.size() == 2) return NewAddRec;
SCEVCommutativeExpr *&Result = SCEVCommExprs[std::make_pair(scMulExpr,
SCEVOps)];
if (Result == 0)
- Result = new SCEVMulExpr(Ops, this);
+ Result = new SCEVMulExpr(Ops);
return Result;
}
/// getUDivExpr - Get a canonical multiply expression, or something simpler if
/// possible.
-SCEVHandle ScalarEvolution::getUDivExpr(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
+const SCEV* ScalarEvolution::getUDivExpr(const SCEV* LHS,
+ const SCEV* RHS) {
assert(getEffectiveSCEVType(LHS->getType()) ==
getEffectiveSCEVType(RHS->getType()) &&
"SCEVUDivExpr operand types don't match!");
getAddRecExpr(getZeroExtendExpr(AR->getStart(), ExtTy),
getZeroExtendExpr(Step, ExtTy),
AR->getLoop())) {
- SmallVector<SCEVHandle, 4> Operands;
+ SmallVector<const SCEV*, 4> Operands;
for (unsigned i = 0, e = AR->getNumOperands(); i != e; ++i)
Operands.push_back(getUDivExpr(AR->getOperand(i), RHS));
return getAddRecExpr(Operands, AR->getLoop());
}
// (A*B)/C --> A*(B/C) if safe and B/C can be folded.
if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(LHS)) {
- SmallVector<SCEVHandle, 4> Operands;
+ SmallVector<const SCEV*, 4> Operands;
for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i)
Operands.push_back(getZeroExtendExpr(M->getOperand(i), ExtTy));
if (getZeroExtendExpr(M, ExtTy) == getMulExpr(Operands))
// Find an operand that's safely divisible.
for (unsigned i = 0, e = M->getNumOperands(); i != e; ++i) {
- SCEVHandle Op = M->getOperand(i);
- SCEVHandle Div = getUDivExpr(Op, RHSC);
+ const SCEV* Op = M->getOperand(i);
+ const SCEV* Div = getUDivExpr(Op, RHSC);
if (!isa<SCEVUDivExpr>(Div) && getMulExpr(Div, RHSC) == Op) {
- const SmallVectorImpl<SCEVHandle> &MOperands = M->getOperands();
- Operands = SmallVector<SCEVHandle, 4>(MOperands.begin(),
+ const SmallVectorImpl<const SCEV*> &MOperands = M->getOperands();
+ Operands = SmallVector<const SCEV*, 4>(MOperands.begin(),
MOperands.end());
Operands[i] = Div;
return getMulExpr(Operands);
}
// (A+B)/C --> (A/C + B/C) if safe and A/C and B/C can be folded.
if (const SCEVAddRecExpr *A = dyn_cast<SCEVAddRecExpr>(LHS)) {
- SmallVector<SCEVHandle, 4> Operands;
+ SmallVector<const SCEV*, 4> Operands;
for (unsigned i = 0, e = A->getNumOperands(); i != e; ++i)
Operands.push_back(getZeroExtendExpr(A->getOperand(i), ExtTy));
if (getZeroExtendExpr(A, ExtTy) == getAddExpr(Operands)) {
Operands.clear();
for (unsigned i = 0, e = A->getNumOperands(); i != e; ++i) {
- SCEVHandle Op = getUDivExpr(A->getOperand(i), RHS);
+ const SCEV* Op = getUDivExpr(A->getOperand(i), RHS);
if (isa<SCEVUDivExpr>(Op) || getMulExpr(Op, RHS) != A->getOperand(i))
break;
Operands.push_back(Op);
if (const SCEVConstant *LHSC = dyn_cast<SCEVConstant>(LHS)) {
Constant *LHSCV = LHSC->getValue();
Constant *RHSCV = RHSC->getValue();
- return getUnknown(ConstantExpr::getUDiv(LHSCV, RHSCV));
+ return getConstant(cast<ConstantInt>(ConstantExpr::getUDiv(LHSCV,
+ RHSCV)));
}
}
SCEVUDivExpr *&Result = SCEVUDivs[std::make_pair(LHS, RHS)];
- if (Result == 0) Result = new SCEVUDivExpr(LHS, RHS, this);
+ if (Result == 0) Result = new SCEVUDivExpr(LHS, RHS);
return Result;
}
/// getAddRecExpr - Get an add recurrence expression for the specified loop.
/// Simplify the expression as much as possible.
-SCEVHandle ScalarEvolution::getAddRecExpr(const SCEVHandle &Start,
- const SCEVHandle &Step, const Loop *L) {
- SmallVector<SCEVHandle, 4> Operands;
+const SCEV* ScalarEvolution::getAddRecExpr(const SCEV* Start,
+ const SCEV* Step, const Loop *L) {
+ SmallVector<const SCEV*, 4> Operands;
Operands.push_back(Start);
if (const SCEVAddRecExpr *StepChrec = dyn_cast<SCEVAddRecExpr>(Step))
if (StepChrec->getLoop() == L) {
/// getAddRecExpr - Get an add recurrence expression for the specified loop.
/// Simplify the expression as much as possible.
-SCEVHandle ScalarEvolution::getAddRecExpr(SmallVectorImpl<SCEVHandle> &Operands,
+const SCEV* ScalarEvolution::getAddRecExpr(SmallVectorImpl<const SCEV*> &Operands,
const Loop *L) {
if (Operands.size() == 1) return Operands[0];
#ifndef NDEBUG
if (const SCEVAddRecExpr *NestedAR = dyn_cast<SCEVAddRecExpr>(Operands[0])) {
const Loop* NestedLoop = NestedAR->getLoop();
if (L->getLoopDepth() < NestedLoop->getLoopDepth()) {
- SmallVector<SCEVHandle, 4> NestedOperands(NestedAR->op_begin(),
+ SmallVector<const SCEV*, 4> NestedOperands(NestedAR->op_begin(),
NestedAR->op_end());
- SCEVHandle NestedARHandle(NestedAR);
Operands[0] = NestedAR->getStart();
NestedOperands[0] = getAddRecExpr(Operands, L);
return getAddRecExpr(NestedOperands, NestedLoop);
std::vector<const SCEV*> SCEVOps(Operands.begin(), Operands.end());
SCEVAddRecExpr *&Result = SCEVAddRecExprs[std::make_pair(L, SCEVOps)];
- if (Result == 0) Result = new SCEVAddRecExpr(Operands, L, this);
+ if (Result == 0) Result = new SCEVAddRecExpr(Operands, L);
return Result;
}
-SCEVHandle ScalarEvolution::getSMaxExpr(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
- SmallVector<SCEVHandle, 2> Ops;
+const SCEV* ScalarEvolution::getSMaxExpr(const SCEV* LHS,
+ const SCEV* RHS) {
+ SmallVector<const SCEV*, 2> Ops;
Ops.push_back(LHS);
Ops.push_back(RHS);
return getSMaxExpr(Ops);
}
-SCEVHandle
-ScalarEvolution::getSMaxExpr(SmallVectorImpl<SCEVHandle> &Ops) {
+const SCEV*
+ScalarEvolution::getSMaxExpr(SmallVectorImpl<const SCEV*> &Ops) {
assert(!Ops.empty() && "Cannot get empty smax!");
if (Ops.size() == 1) return Ops[0];
#ifndef NDEBUG
std::vector<const SCEV*> SCEVOps(Ops.begin(), Ops.end());
SCEVCommutativeExpr *&Result = SCEVCommExprs[std::make_pair(scSMaxExpr,
SCEVOps)];
- if (Result == 0) Result = new SCEVSMaxExpr(Ops, this);
+ if (Result == 0) Result = new SCEVSMaxExpr(Ops);
return Result;
}
-SCEVHandle ScalarEvolution::getUMaxExpr(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
- SmallVector<SCEVHandle, 2> Ops;
+const SCEV* ScalarEvolution::getUMaxExpr(const SCEV* LHS,
+ const SCEV* RHS) {
+ SmallVector<const SCEV*, 2> Ops;
Ops.push_back(LHS);
Ops.push_back(RHS);
return getUMaxExpr(Ops);
}
-SCEVHandle
-ScalarEvolution::getUMaxExpr(SmallVectorImpl<SCEVHandle> &Ops) {
+const SCEV*
+ScalarEvolution::getUMaxExpr(SmallVectorImpl<const SCEV*> &Ops) {
assert(!Ops.empty() && "Cannot get empty umax!");
if (Ops.size() == 1) return Ops[0];
#ifndef NDEBUG
std::vector<const SCEV*> SCEVOps(Ops.begin(), Ops.end());
SCEVCommutativeExpr *&Result = SCEVCommExprs[std::make_pair(scUMaxExpr,
SCEVOps)];
- if (Result == 0) Result = new SCEVUMaxExpr(Ops, this);
+ if (Result == 0) Result = new SCEVUMaxExpr(Ops);
return Result;
}
-SCEVHandle ScalarEvolution::getSMinExpr(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
+const SCEV* ScalarEvolution::getSMinExpr(const SCEV* LHS,
+ const SCEV* RHS) {
// ~smax(~x, ~y) == smin(x, y).
return getNotSCEV(getSMaxExpr(getNotSCEV(LHS), getNotSCEV(RHS)));
}
-SCEVHandle ScalarEvolution::getUMinExpr(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
+const SCEV* ScalarEvolution::getUMinExpr(const SCEV* LHS,
+ const SCEV* RHS) {
// ~umax(~x, ~y) == umin(x, y)
return getNotSCEV(getUMaxExpr(getNotSCEV(LHS), getNotSCEV(RHS)));
}
-SCEVHandle ScalarEvolution::getUnknown(Value *V) {
- if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
- return getConstant(CI);
- if (isa<ConstantPointerNull>(V))
- return getIntegerSCEV(0, V->getType());
+const SCEV* ScalarEvolution::getUnknown(Value *V) {
+ // Don't attempt to do anything other than create a SCEVUnknown object
+ // here. createSCEV only calls getUnknown after checking for all other
+ // interesting possibilities, and any other code that calls getUnknown
+ // is doing so in order to hide a value from SCEV canonicalization.
+
SCEVUnknown *&Result = SCEVUnknowns[V];
- if (Result == 0) Result = new SCEVUnknown(V, this);
+ if (Result == 0) Result = new SCEVUnknown(V);
return Result;
}
return TD->getIntPtrType();
}
-SCEVHandle ScalarEvolution::getCouldNotCompute() {
+const SCEV* ScalarEvolution::getCouldNotCompute() {
return CouldNotCompute;
}
/// getSCEV - Return an existing SCEV if it exists, otherwise analyze the
/// expression and create a new one.
-SCEVHandle ScalarEvolution::getSCEV(Value *V) {
+const SCEV* ScalarEvolution::getSCEV(Value *V) {
assert(isSCEVable(V->getType()) && "Value is not SCEVable!");
- std::map<SCEVCallbackVH, SCEVHandle>::iterator I = Scalars.find(V);
+ std::map<SCEVCallbackVH, const SCEV*>::iterator I = Scalars.find(V);
if (I != Scalars.end()) return I->second;
- SCEVHandle S = createSCEV(V);
+ const SCEV* S = createSCEV(V);
Scalars.insert(std::make_pair(SCEVCallbackVH(V, this), S));
return S;
}
-/// getIntegerSCEV - Given an integer or FP type, create a constant for the
+/// getIntegerSCEV - Given a SCEVable type, create a constant for the
/// specified signed integer value and return a SCEV for the constant.
-SCEVHandle ScalarEvolution::getIntegerSCEV(int Val, const Type *Ty) {
- Ty = getEffectiveSCEVType(Ty);
- Constant *C;
- if (Val == 0)
- C = Constant::getNullValue(Ty);
- else if (Ty->isFloatingPoint())
- C = ConstantFP::get(APFloat(Ty==Type::FloatTy ? APFloat::IEEEsingle :
- APFloat::IEEEdouble, Val));
- else
- C = ConstantInt::get(Ty, Val);
- return getUnknown(C);
+const SCEV* ScalarEvolution::getIntegerSCEV(int Val, const Type *Ty) {
+ const IntegerType *ITy = cast<IntegerType>(getEffectiveSCEVType(Ty));
+ return getConstant(ConstantInt::get(ITy, Val));
}
/// getNegativeSCEV - Return a SCEV corresponding to -V = -1*V
///
-SCEVHandle ScalarEvolution::getNegativeSCEV(const SCEVHandle &V) {
+const SCEV* ScalarEvolution::getNegativeSCEV(const SCEV* V) {
if (const SCEVConstant *VC = dyn_cast<SCEVConstant>(V))
- return getUnknown(ConstantExpr::getNeg(VC->getValue()));
+ return getConstant(cast<ConstantInt>(ConstantExpr::getNeg(VC->getValue())));
const Type *Ty = V->getType();
Ty = getEffectiveSCEVType(Ty);
}
/// getNotSCEV - Return a SCEV corresponding to ~V = -1-V
-SCEVHandle ScalarEvolution::getNotSCEV(const SCEVHandle &V) {
+const SCEV* ScalarEvolution::getNotSCEV(const SCEV* V) {
if (const SCEVConstant *VC = dyn_cast<SCEVConstant>(V))
- return getUnknown(ConstantExpr::getNot(VC->getValue()));
+ return getConstant(cast<ConstantInt>(ConstantExpr::getNot(VC->getValue())));
const Type *Ty = V->getType();
Ty = getEffectiveSCEVType(Ty);
- SCEVHandle AllOnes = getConstant(ConstantInt::getAllOnesValue(Ty));
+ const SCEV* AllOnes = getConstant(ConstantInt::getAllOnesValue(Ty));
return getMinusSCEV(AllOnes, V);
}
/// getMinusSCEV - Return a SCEV corresponding to LHS - RHS.
///
-SCEVHandle ScalarEvolution::getMinusSCEV(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
+const SCEV* ScalarEvolution::getMinusSCEV(const SCEV* LHS,
+ const SCEV* RHS) {
// X - Y --> X + -Y
return getAddExpr(LHS, getNegativeSCEV(RHS));
}
/// getTruncateOrZeroExtend - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. If the type must be extended, it is zero
/// extended.
-SCEVHandle
-ScalarEvolution::getTruncateOrZeroExtend(const SCEVHandle &V,
+const SCEV*
+ScalarEvolution::getTruncateOrZeroExtend(const SCEV* V,
const Type *Ty) {
const Type *SrcTy = V->getType();
assert((SrcTy->isInteger() || (TD && isa<PointerType>(SrcTy))) &&
/// getTruncateOrSignExtend - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. If the type must be extended, it is sign
/// extended.
-SCEVHandle
-ScalarEvolution::getTruncateOrSignExtend(const SCEVHandle &V,
+const SCEV*
+ScalarEvolution::getTruncateOrSignExtend(const SCEV* V,
const Type *Ty) {
const Type *SrcTy = V->getType();
assert((SrcTy->isInteger() || (TD && isa<PointerType>(SrcTy))) &&
/// getNoopOrZeroExtend - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. If the type must be extended, it is zero
/// extended. The conversion must not be narrowing.
-SCEVHandle
-ScalarEvolution::getNoopOrZeroExtend(const SCEVHandle &V, const Type *Ty) {
+const SCEV*
+ScalarEvolution::getNoopOrZeroExtend(const SCEV* V, const Type *Ty) {
const Type *SrcTy = V->getType();
assert((SrcTy->isInteger() || (TD && isa<PointerType>(SrcTy))) &&
(Ty->isInteger() || (TD && isa<PointerType>(Ty))) &&
/// getNoopOrSignExtend - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. If the type must be extended, it is sign
/// extended. The conversion must not be narrowing.
-SCEVHandle
-ScalarEvolution::getNoopOrSignExtend(const SCEVHandle &V, const Type *Ty) {
+const SCEV*
+ScalarEvolution::getNoopOrSignExtend(const SCEV* V, const Type *Ty) {
const Type *SrcTy = V->getType();
assert((SrcTy->isInteger() || (TD && isa<PointerType>(SrcTy))) &&
(Ty->isInteger() || (TD && isa<PointerType>(Ty))) &&
/// the input value to the specified type. If the type must be extended,
/// it is extended with unspecified bits. The conversion must not be
/// narrowing.
-SCEVHandle
-ScalarEvolution::getNoopOrAnyExtend(const SCEVHandle &V, const Type *Ty) {
+const SCEV*
+ScalarEvolution::getNoopOrAnyExtend(const SCEV* V, const Type *Ty) {
const Type *SrcTy = V->getType();
assert((SrcTy->isInteger() || (TD && isa<PointerType>(SrcTy))) &&
(Ty->isInteger() || (TD && isa<PointerType>(Ty))) &&
/// getTruncateOrNoop - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. The conversion must not be widening.
-SCEVHandle
-ScalarEvolution::getTruncateOrNoop(const SCEVHandle &V, const Type *Ty) {
+const SCEV*
+ScalarEvolution::getTruncateOrNoop(const SCEV* V, const Type *Ty) {
const Type *SrcTy = V->getType();
assert((SrcTy->isInteger() || (TD && isa<PointerType>(SrcTy))) &&
(Ty->isInteger() || (TD && isa<PointerType>(Ty))) &&
/// getUMaxFromMismatchedTypes - Promote the operands to the wider of
/// the types using zero-extension, and then perform a umax operation
/// with them.
-SCEVHandle ScalarEvolution::getUMaxFromMismatchedTypes(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
- SCEVHandle PromotedLHS = LHS;
- SCEVHandle PromotedRHS = RHS;
+const SCEV* ScalarEvolution::getUMaxFromMismatchedTypes(const SCEV* LHS,
+ const SCEV* RHS) {
+ const SCEV* PromotedLHS = LHS;
+ const SCEV* PromotedRHS = RHS;
if (getTypeSizeInBits(LHS->getType()) > getTypeSizeInBits(RHS->getType()))
PromotedRHS = getZeroExtendExpr(RHS, LHS->getType());
/// getUMinFromMismatchedTypes - Promote the operands to the wider of
/// the types using zero-extension, and then perform a umin operation
/// with them.
-SCEVHandle ScalarEvolution::getUMinFromMismatchedTypes(const SCEVHandle &LHS,
- const SCEVHandle &RHS) {
- SCEVHandle PromotedLHS = LHS;
- SCEVHandle PromotedRHS = RHS;
+const SCEV* ScalarEvolution::getUMinFromMismatchedTypes(const SCEV* LHS,
+ const SCEV* RHS) {
+ const SCEV* PromotedLHS = LHS;
+ const SCEV* PromotedRHS = RHS;
if (getTypeSizeInBits(LHS->getType()) > getTypeSizeInBits(RHS->getType()))
PromotedRHS = getZeroExtendExpr(RHS, LHS->getType());
/// the specified instruction and replaces any references to the symbolic value
/// SymName with the specified value. This is used during PHI resolution.
void ScalarEvolution::
-ReplaceSymbolicValueWithConcrete(Instruction *I, const SCEVHandle &SymName,
- const SCEVHandle &NewVal) {
- std::map<SCEVCallbackVH, SCEVHandle>::iterator SI =
+ReplaceSymbolicValueWithConcrete(Instruction *I, const SCEV* SymName,
+ const SCEV* NewVal) {
+ std::map<SCEVCallbackVH, const SCEV*>::iterator SI =
Scalars.find(SCEVCallbackVH(I, this));
if (SI == Scalars.end()) return;
- SCEVHandle NV =
+ const SCEV* NV =
SI->second->replaceSymbolicValuesWithConcrete(SymName, NewVal, *this);
if (NV == SI->second) return; // No change.
/// createNodeForPHI - PHI nodes have two cases. Either the PHI node exists in
/// a loop header, making it a potential recurrence, or it doesn't.
///
-SCEVHandle ScalarEvolution::createNodeForPHI(PHINode *PN) {
+const SCEV* ScalarEvolution::createNodeForPHI(PHINode *PN) {
if (PN->getNumIncomingValues() == 2) // The loops have been canonicalized.
if (const Loop *L = LI->getLoopFor(PN->getParent()))
if (L->getHeader() == PN->getParent()) {
unsigned BackEdge = IncomingEdge^1;
// While we are analyzing this PHI node, handle its value symbolically.
- SCEVHandle SymbolicName = getUnknown(PN);
+ const SCEV* SymbolicName = getUnknown(PN);
assert(Scalars.find(PN) == Scalars.end() &&
"PHI node already processed?");
Scalars.insert(std::make_pair(SCEVCallbackVH(PN, this), SymbolicName));
// Using this symbolic name for the PHI, analyze the value coming around
// the back-edge.
- SCEVHandle BEValue = getSCEV(PN->getIncomingValue(BackEdge));
+ const SCEV* BEValue = getSCEV(PN->getIncomingValue(BackEdge));
// NOTE: If BEValue is loop invariant, we know that the PHI node just
// has a special value for the first iteration of the loop.
if (FoundIndex != Add->getNumOperands()) {
// Create an add with everything but the specified operand.
- SmallVector<SCEVHandle, 8> Ops;
+ SmallVector<const SCEV*, 8> Ops;
for (unsigned i = 0, e = Add->getNumOperands(); i != e; ++i)
if (i != FoundIndex)
Ops.push_back(Add->getOperand(i));
- SCEVHandle Accum = getAddExpr(Ops);
+ const SCEV* Accum = getAddExpr(Ops);
// This is not a valid addrec if the step amount is varying each
// loop iteration, but is not itself an addrec in this loop.
if (Accum->isLoopInvariant(L) ||
(isa<SCEVAddRecExpr>(Accum) &&
cast<SCEVAddRecExpr>(Accum)->getLoop() == L)) {
- SCEVHandle StartVal = getSCEV(PN->getIncomingValue(IncomingEdge));
- SCEVHandle PHISCEV = getAddRecExpr(StartVal, Accum, L);
+ const SCEV* StartVal = getSCEV(PN->getIncomingValue(IncomingEdge));
+ const SCEV* PHISCEV = getAddRecExpr(StartVal, Accum, L);
// Okay, for the entire analysis of this edge we assumed the PHI
// to be symbolic. We now need to go back and update all of the
// Because the other in-value of i (0) fits the evolution of BEValue
// i really is an addrec evolution.
if (AddRec->getLoop() == L && AddRec->isAffine()) {
- SCEVHandle StartVal = getSCEV(PN->getIncomingValue(IncomingEdge));
+ const SCEV* StartVal = getSCEV(PN->getIncomingValue(IncomingEdge));
// If StartVal = j.start - j.stride, we can use StartVal as the
// initial step of the addrec evolution.
if (StartVal == getMinusSCEV(AddRec->getOperand(0),
AddRec->getOperand(1))) {
- SCEVHandle PHISCEV =
+ const SCEV* PHISCEV =
getAddRecExpr(StartVal, AddRec->getOperand(1), L);
// Okay, for the entire analysis of this edge we assumed the PHI
/// createNodeForGEP - Expand GEP instructions into add and multiply
/// operations. This allows them to be analyzed by regular SCEV code.
///
-SCEVHandle ScalarEvolution::createNodeForGEP(User *GEP) {
+const SCEV* ScalarEvolution::createNodeForGEP(User *GEP) {
const Type *IntPtrTy = TD->getIntPtrType();
Value *Base = GEP->getOperand(0);
// Don't attempt to analyze GEPs over unsized objects.
if (!cast<PointerType>(Base->getType())->getElementType()->isSized())
return getUnknown(GEP);
- SCEVHandle TotalOffset = getIntegerSCEV(0, IntPtrTy);
+ const SCEV* TotalOffset = getIntegerSCEV(0, IntPtrTy);
gep_type_iterator GTI = gep_type_begin(GEP);
for (GetElementPtrInst::op_iterator I = next(GEP->op_begin()),
E = GEP->op_end();
getIntegerSCEV(Offset, IntPtrTy));
} else {
// For an array, add the element offset, explicitly scaled.
- SCEVHandle LocalOffset = getSCEV(Index);
+ const SCEV* LocalOffset = getSCEV(Index);
if (!isa<PointerType>(LocalOffset->getType()))
// Getelementptr indicies are signed.
LocalOffset = getTruncateOrSignExtend(LocalOffset,
/// the minimum number of times S is divisible by 2. For example, given {4,+,8}
/// it returns 2. If S is guaranteed to be 0, it returns the bitwidth of S.
uint32_t
-ScalarEvolution::GetMinTrailingZeros(const SCEVHandle &S) {
+ScalarEvolution::GetMinTrailingZeros(const SCEV* S) {
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
return C->getValue()->getValue().countTrailingZeros();
}
uint32_t
-ScalarEvolution::GetMinLeadingZeros(const SCEVHandle &S) {
+ScalarEvolution::GetMinLeadingZeros(const SCEV* S) {
// TODO: Handle other SCEV expression types here.
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
}
uint32_t
-ScalarEvolution::GetMinSignBits(const SCEVHandle &S) {
+ScalarEvolution::GetMinSignBits(const SCEV* S) {
// TODO: Handle other SCEV expression types here.
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S)) {
getTypeSizeInBits(C->getOperand()->getType()));
}
+ if (const SCEVAddExpr *A = dyn_cast<SCEVAddExpr>(S)) {
+ unsigned BitWidth = getTypeSizeInBits(A->getType());
+
+ // Special case decrementing a value (ADD X, -1):
+ if (const SCEVConstant *CRHS = dyn_cast<SCEVConstant>(A->getOperand(0)))
+ if (CRHS->isAllOnesValue()) {
+ SmallVector<const SCEV *, 4> OtherOps(A->op_begin() + 1, A->op_end());
+ const SCEV *OtherOpsAdd = getAddExpr(OtherOps);
+ unsigned LZ = GetMinLeadingZeros(OtherOpsAdd);
+
+ // If the input is known to be 0 or 1, the output is 0/-1, which is all
+ // sign bits set.
+ if (LZ == BitWidth - 1)
+ return BitWidth;
+
+ // If we are subtracting one from a positive number, there is no carry
+ // out of the result.
+ if (LZ > 0)
+ return GetMinSignBits(OtherOpsAdd);
+ }
+
+ // Add can have at most one carry bit. Thus we know that the output
+ // is, at worst, one more bit than the inputs.
+ unsigned Min = BitWidth;
+ for (unsigned i = 0, e = A->getNumOperands(); i != e; ++i) {
+ unsigned N = GetMinSignBits(A->getOperand(i));
+ Min = std::min(Min, N) - 1;
+ if (Min == 0) return 1;
+ }
+ return 1;
+ }
+
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
// For a SCEVUnknown, ask ValueTracking.
return ComputeNumSignBits(U->getValue(), TD);
/// createSCEV - We know that there is no SCEV for the specified value.
/// Analyze the expression.
///
-SCEVHandle ScalarEvolution::createSCEV(Value *V) {
+const SCEV* ScalarEvolution::createSCEV(Value *V) {
if (!isSCEVable(V->getType()))
return getUnknown(V);
Opcode = I->getOpcode();
else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
Opcode = CE->getOpcode();
+ else if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
+ return getConstant(CI);
+ else if (isa<ConstantPointerNull>(V))
+ return getIntegerSCEV(0, V->getType());
+ else if (isa<UndefValue>(V))
+ return getIntegerSCEV(0, V->getType());
else
return getUnknown(V);
// In order for this transformation to be safe, the LHS must be of the
// form X*(2^n) and the Or constant must be less than 2^n.
if (ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1))) {
- SCEVHandle LHS = getSCEV(U->getOperand(0));
+ const SCEV* LHS = getSCEV(U->getOperand(0));
const APInt &CIVal = CI->getValue();
if (GetMinTrailingZeros(LHS) >=
(CIVal.getBitWidth() - CIVal.countLeadingZeros()))
if (const SCEVZeroExtendExpr *Z =
dyn_cast<SCEVZeroExtendExpr>(getSCEV(U->getOperand(0)))) {
const Type *UTy = U->getType();
- SCEVHandle Z0 = Z->getOperand();
+ const SCEV* Z0 = Z->getOperand();
const Type *Z0Ty = Z0->getType();
unsigned Z0TySize = getTypeSizeInBits(Z0Ty);
/// loop-invariant backedge-taken count (see
/// hasLoopInvariantBackedgeTakenCount).
///
-SCEVHandle ScalarEvolution::getBackedgeTakenCount(const Loop *L) {
+const SCEV* ScalarEvolution::getBackedgeTakenCount(const Loop *L) {
return getBackedgeTakenInfo(L).Exact;
}
/// getMaxBackedgeTakenCount - Similar to getBackedgeTakenCount, except
/// return the least SCEV value that is known never to be less than the
/// actual backedge taken count.
-SCEVHandle ScalarEvolution::getMaxBackedgeTakenCount(const Loop *L) {
+const SCEV* ScalarEvolution::getMaxBackedgeTakenCount(const Loop *L) {
return getBackedgeTakenInfo(L).Max;
}
SmallVector<Instruction *, 16> Worklist;
for (BasicBlock::iterator I = Header->begin();
PHINode *PN = dyn_cast<PHINode>(I); ++I) {
- std::map<SCEVCallbackVH, SCEVHandle>::iterator It = Scalars.find((Value*)I);
+ std::map<SCEVCallbackVH, const SCEV*>::iterator It = Scalars.find((Value*)I);
if (It != Scalars.end() && !isa<SCEVUnknown>(It->second))
Worklist.push_back(PN);
}
L->getExitingBlocks(ExitingBlocks);
// Examine all exits and pick the most conservative values.
- SCEVHandle BECount = CouldNotCompute;
- SCEVHandle MaxBECount = CouldNotCompute;
+ const SCEV* BECount = CouldNotCompute;
+ const SCEV* MaxBECount = CouldNotCompute;
bool CouldNotComputeBECount = false;
- bool CouldNotComputeMaxBECount = false;
for (unsigned i = 0, e = ExitingBlocks.size(); i != e; ++i) {
BackedgeTakenInfo NewBTI =
ComputeBackedgeTakenCountFromExit(L, ExitingBlocks[i]);
if (NewBTI.Exact == CouldNotCompute) {
// We couldn't compute an exact value for this exit, so
- // we don't be able to compute an exact value for the loop.
+ // we won't be able to compute an exact value for the loop.
CouldNotComputeBECount = true;
BECount = CouldNotCompute;
} else if (!CouldNotComputeBECount) {
if (BECount == CouldNotCompute)
BECount = NewBTI.Exact;
- else {
- // TODO: More analysis could be done here. For example, a
- // loop with a short-circuiting && operator has an exact count
- // of the min of both sides.
- CouldNotComputeBECount = true;
- BECount = CouldNotCompute;
- }
- }
- if (NewBTI.Max == CouldNotCompute) {
- // We couldn't compute an maximum value for this exit, so
- // we don't be able to compute an maximum value for the loop.
- CouldNotComputeMaxBECount = true;
- MaxBECount = CouldNotCompute;
- } else if (!CouldNotComputeMaxBECount) {
- if (MaxBECount == CouldNotCompute)
- MaxBECount = NewBTI.Max;
else
- MaxBECount = getUMaxFromMismatchedTypes(MaxBECount, NewBTI.Max);
+ BECount = getUMinFromMismatchedTypes(BECount, NewBTI.Exact);
}
+ if (MaxBECount == CouldNotCompute)
+ MaxBECount = NewBTI.Max;
+ else if (NewBTI.Max != CouldNotCompute)
+ MaxBECount = getUMinFromMismatchedTypes(MaxBECount, NewBTI.Max);
}
return BackedgeTakenInfo(BECount, MaxBECount);
Value *ExitCond,
BasicBlock *TBB,
BasicBlock *FBB) {
- // Check if the controlling expression for this loop is an and or or. In
- // such cases, an exact backedge-taken count may be infeasible, but a
- // maximum count may still be feasible.
+ // Check if the controlling expression for this loop is an And or Or.
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(ExitCond)) {
if (BO->getOpcode() == Instruction::And) {
// Recurse on the operands of the and.
ComputeBackedgeTakenCountFromExitCond(L, BO->getOperand(0), TBB, FBB);
BackedgeTakenInfo BTI1 =
ComputeBackedgeTakenCountFromExitCond(L, BO->getOperand(1), TBB, FBB);
- SCEVHandle BECount = CouldNotCompute;
- SCEVHandle MaxBECount = CouldNotCompute;
+ const SCEV* BECount = CouldNotCompute;
+ const SCEV* MaxBECount = CouldNotCompute;
if (L->contains(TBB)) {
// Both conditions must be true for the loop to continue executing.
// Choose the less conservative count.
- if (BTI0.Exact == CouldNotCompute)
- BECount = BTI1.Exact;
- else if (BTI1.Exact == CouldNotCompute)
- BECount = BTI0.Exact;
+ if (BTI0.Exact == CouldNotCompute || BTI1.Exact == CouldNotCompute)
+ BECount = CouldNotCompute;
else
BECount = getUMinFromMismatchedTypes(BTI0.Exact, BTI1.Exact);
if (BTI0.Max == CouldNotCompute)
ComputeBackedgeTakenCountFromExitCond(L, BO->getOperand(0), TBB, FBB);
BackedgeTakenInfo BTI1 =
ComputeBackedgeTakenCountFromExitCond(L, BO->getOperand(1), TBB, FBB);
- SCEVHandle BECount = CouldNotCompute;
- SCEVHandle MaxBECount = CouldNotCompute;
+ const SCEV* BECount = CouldNotCompute;
+ const SCEV* MaxBECount = CouldNotCompute;
if (L->contains(FBB)) {
// Both conditions must be false for the loop to continue executing.
// Choose the less conservative count.
- if (BTI0.Exact == CouldNotCompute)
- BECount = BTI1.Exact;
- else if (BTI1.Exact == CouldNotCompute)
- BECount = BTI0.Exact;
+ if (BTI0.Exact == CouldNotCompute || BTI1.Exact == CouldNotCompute)
+ BECount = CouldNotCompute;
else
BECount = getUMinFromMismatchedTypes(BTI0.Exact, BTI1.Exact);
if (BTI0.Max == CouldNotCompute)
// Handle common loops like: for (X = "string"; *X; ++X)
if (LoadInst *LI = dyn_cast<LoadInst>(ExitCond->getOperand(0)))
if (Constant *RHS = dyn_cast<Constant>(ExitCond->getOperand(1))) {
- SCEVHandle ItCnt =
+ const SCEV* ItCnt =
ComputeLoadConstantCompareBackedgeTakenCount(LI, RHS, L, Cond);
if (!isa<SCEVCouldNotCompute>(ItCnt)) {
unsigned BitWidth = getTypeSizeInBits(ItCnt->getType());
}
}
- SCEVHandle LHS = getSCEV(ExitCond->getOperand(0));
- SCEVHandle RHS = getSCEV(ExitCond->getOperand(1));
+ const SCEV* LHS = getSCEV(ExitCond->getOperand(0));
+ const SCEV* RHS = getSCEV(ExitCond->getOperand(1));
// Try to evaluate any dependencies out of the loop.
LHS = getSCEVAtScope(LHS, L);
ConstantRange CompRange(
ICmpInst::makeConstantRange(Cond, RHSC->getValue()->getValue()));
- SCEVHandle Ret = AddRec->getNumIterationsInRange(CompRange, *this);
+ const SCEV* Ret = AddRec->getNumIterationsInRange(CompRange, *this);
if (!isa<SCEVCouldNotCompute>(Ret)) return Ret;
}
switch (Cond) {
case ICmpInst::ICMP_NE: { // while (X != Y)
// Convert to: while (X-Y != 0)
- SCEVHandle TC = HowFarToZero(getMinusSCEV(LHS, RHS), L);
+ const SCEV* TC = HowFarToZero(getMinusSCEV(LHS, RHS), L);
if (!isa<SCEVCouldNotCompute>(TC)) return TC;
break;
}
case ICmpInst::ICMP_EQ: {
// Convert to: while (X-Y == 0) // while (X == Y)
- SCEVHandle TC = HowFarToNonZero(getMinusSCEV(LHS, RHS), L);
+ const SCEV* TC = HowFarToNonZero(getMinusSCEV(LHS, RHS), L);
if (!isa<SCEVCouldNotCompute>(TC)) return TC;
break;
}
static ConstantInt *
EvaluateConstantChrecAtConstant(const SCEVAddRecExpr *AddRec, ConstantInt *C,
ScalarEvolution &SE) {
- SCEVHandle InVal = SE.getConstant(C);
- SCEVHandle Val = AddRec->evaluateAtIteration(InVal, SE);
+ const SCEV* InVal = SE.getConstant(C);
+ const SCEV* Val = AddRec->evaluateAtIteration(InVal, SE);
assert(isa<SCEVConstant>(Val) &&
"Evaluation of SCEV at constant didn't fold correctly?");
return cast<SCEVConstant>(Val)->getValue();
/// ComputeLoadConstantCompareBackedgeTakenCount - Given an exit condition of
/// 'icmp op load X, cst', try to see if we can compute the backedge
/// execution count.
-SCEVHandle ScalarEvolution::
+const SCEV* ScalarEvolution::
ComputeLoadConstantCompareBackedgeTakenCount(LoadInst *LI, Constant *RHS,
const Loop *L,
ICmpInst::Predicate predicate) {
// Okay, we know we have a (load (gep GV, 0, X)) comparison with a constant.
// Check to see if X is a loop variant variable value now.
- SCEVHandle Idx = getSCEV(VarIdx);
+ const SCEV* Idx = getSCEV(VarIdx);
Idx = getSCEVAtScope(Idx, L);
// We can only recognize very limited forms of loop index expressions, in
/// try to evaluate a few iterations of the loop until we get the exit
/// condition gets a value of ExitWhen (true or false). If we cannot
/// evaluate the trip count of the loop, return CouldNotCompute.
-SCEVHandle ScalarEvolution::
+const SCEV* ScalarEvolution::
ComputeBackedgeTakenCountExhaustively(const Loop *L, Value *Cond, bool ExitWhen) {
PHINode *PN = getConstantEvolvingPHI(Cond, L);
if (PN == 0) return CouldNotCompute;
///
/// In the case that a relevant loop exit value cannot be computed, the
/// original value V is returned.
-SCEVHandle ScalarEvolution::getSCEVAtScope(const SCEV *V, const Loop *L) {
+const SCEV* ScalarEvolution::getSCEVAtScope(const SCEV *V, const Loop *L) {
// FIXME: this should be turned into a virtual method on SCEV!
if (isa<SCEVConstant>(V)) return V;
// to see if the loop that contains it has a known backedge-taken
// count. If so, we may be able to force computation of the exit
// value.
- SCEVHandle BackedgeTakenCount = getBackedgeTakenCount(LI);
+ const SCEV* BackedgeTakenCount = getBackedgeTakenCount(LI);
if (const SCEVConstant *BTCC =
dyn_cast<SCEVConstant>(BackedgeTakenCount)) {
// Okay, we know how many times the containing loop executes. If
if (!isSCEVable(Op->getType()))
return V;
- SCEVHandle OpV = getSCEVAtScope(getSCEV(Op), L);
+ const SCEV* OpV = getSCEVAtScope(getSCEV(Op), L);
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(OpV)) {
Constant *C = SC->getValue();
if (C->getType() != Op->getType())
// Avoid performing the look-up in the common case where the specified
// expression has no loop-variant portions.
for (unsigned i = 0, e = Comm->getNumOperands(); i != e; ++i) {
- SCEVHandle OpAtScope = getSCEVAtScope(Comm->getOperand(i), L);
+ const SCEV* OpAtScope = getSCEVAtScope(Comm->getOperand(i), L);
if (OpAtScope != Comm->getOperand(i)) {
// Okay, at least one of these operands is loop variant but might be
// foldable. Build a new instance of the folded commutative expression.
- SmallVector<SCEVHandle, 8> NewOps(Comm->op_begin(), Comm->op_begin()+i);
+ SmallVector<const SCEV*, 8> NewOps(Comm->op_begin(), Comm->op_begin()+i);
NewOps.push_back(OpAtScope);
for (++i; i != e; ++i) {
}
if (const SCEVUDivExpr *Div = dyn_cast<SCEVUDivExpr>(V)) {
- SCEVHandle LHS = getSCEVAtScope(Div->getLHS(), L);
- SCEVHandle RHS = getSCEVAtScope(Div->getRHS(), L);
+ const SCEV* LHS = getSCEVAtScope(Div->getLHS(), L);
+ const SCEV* RHS = getSCEVAtScope(Div->getRHS(), L);
if (LHS == Div->getLHS() && RHS == Div->getRHS())
return Div; // must be loop invariant
return getUDivExpr(LHS, RHS);
if (!L || !AddRec->getLoop()->contains(L->getHeader())) {
// To evaluate this recurrence, we need to know how many times the AddRec
// loop iterates. Compute this now.
- SCEVHandle BackedgeTakenCount = getBackedgeTakenCount(AddRec->getLoop());
+ const SCEV* BackedgeTakenCount = getBackedgeTakenCount(AddRec->getLoop());
if (BackedgeTakenCount == CouldNotCompute) return AddRec;
// Then, evaluate the AddRec.
}
if (const SCEVZeroExtendExpr *Cast = dyn_cast<SCEVZeroExtendExpr>(V)) {
- SCEVHandle Op = getSCEVAtScope(Cast->getOperand(), L);
+ const SCEV* Op = getSCEVAtScope(Cast->getOperand(), L);
if (Op == Cast->getOperand())
return Cast; // must be loop invariant
return getZeroExtendExpr(Op, Cast->getType());
}
if (const SCEVSignExtendExpr *Cast = dyn_cast<SCEVSignExtendExpr>(V)) {
- SCEVHandle Op = getSCEVAtScope(Cast->getOperand(), L);
+ const SCEV* Op = getSCEVAtScope(Cast->getOperand(), L);
if (Op == Cast->getOperand())
return Cast; // must be loop invariant
return getSignExtendExpr(Op, Cast->getType());
}
if (const SCEVTruncateExpr *Cast = dyn_cast<SCEVTruncateExpr>(V)) {
- SCEVHandle Op = getSCEVAtScope(Cast->getOperand(), L);
+ const SCEV* Op = getSCEVAtScope(Cast->getOperand(), L);
if (Op == Cast->getOperand())
return Cast; // must be loop invariant
return getTruncateExpr(Op, Cast->getType());
/// getSCEVAtScope - This is a convenience function which does
/// getSCEVAtScope(getSCEV(V), L).
-SCEVHandle ScalarEvolution::getSCEVAtScope(Value *V, const Loop *L) {
+const SCEV* ScalarEvolution::getSCEVAtScope(Value *V, const Loop *L) {
return getSCEVAtScope(getSCEV(V), L);
}
/// A and B isn't important.
///
/// If the equation does not have a solution, SCEVCouldNotCompute is returned.
-static SCEVHandle SolveLinEquationWithOverflow(const APInt &A, const APInt &B,
+static const SCEV* SolveLinEquationWithOverflow(const APInt &A, const APInt &B,
ScalarEvolution &SE) {
uint32_t BW = A.getBitWidth();
assert(BW == B.getBitWidth() && "Bit widths must be the same.");
/// given quadratic chrec {L,+,M,+,N}. This returns either the two roots (which
/// might be the same) or two SCEVCouldNotCompute objects.
///
-static std::pair<SCEVHandle,SCEVHandle>
+static std::pair<const SCEV*,const SCEV*>
SolveQuadraticEquation(const SCEVAddRecExpr *AddRec, ScalarEvolution &SE) {
assert(AddRec->getNumOperands() == 3 && "This is not a quadratic chrec!");
const SCEVConstant *LC = dyn_cast<SCEVConstant>(AddRec->getOperand(0));
/// HowFarToZero - Return the number of times a backedge comparing the specified
/// value to zero will execute. If not computable, return CouldNotCompute.
-SCEVHandle ScalarEvolution::HowFarToZero(const SCEV *V, const Loop *L) {
+const SCEV* ScalarEvolution::HowFarToZero(const SCEV *V, const Loop *L) {
// If the value is a constant
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(V)) {
// If the value is already zero, the branch will execute zero times.
// where BW is the common bit width of Start and Step.
// Get the initial value for the loop.
- SCEVHandle Start = getSCEVAtScope(AddRec->getStart(), L->getParentLoop());
- SCEVHandle Step = getSCEVAtScope(AddRec->getOperand(1), L->getParentLoop());
+ const SCEV* Start = getSCEVAtScope(AddRec->getStart(), L->getParentLoop());
+ const SCEV* Step = getSCEVAtScope(AddRec->getOperand(1), L->getParentLoop());
if (const SCEVConstant *StepC = dyn_cast<SCEVConstant>(Step)) {
// For now we handle only constant steps.
} else if (AddRec->isQuadratic() && AddRec->getType()->isInteger()) {
// If this is a quadratic (3-term) AddRec {L,+,M,+,N}, find the roots of
// the quadratic equation to solve it.
- std::pair<SCEVHandle,SCEVHandle> Roots = SolveQuadraticEquation(AddRec,
+ std::pair<const SCEV*,const SCEV*> Roots = SolveQuadraticEquation(AddRec,
*this);
const SCEVConstant *R1 = dyn_cast<SCEVConstant>(Roots.first);
const SCEVConstant *R2 = dyn_cast<SCEVConstant>(Roots.second);
// We can only use this value if the chrec ends up with an exact zero
// value at this index. When solving for "X*X != 5", for example, we
// should not accept a root of 2.
- SCEVHandle Val = AddRec->evaluateAtIteration(R1, *this);
+ const SCEV* Val = AddRec->evaluateAtIteration(R1, *this);
if (Val->isZero())
return R1; // We found a quadratic root!
}
/// HowFarToNonZero - Return the number of times a backedge checking the
/// specified value for nonzero will execute. If not computable, return
/// CouldNotCompute
-SCEVHandle ScalarEvolution::HowFarToNonZero(const SCEV *V, const Loop *L) {
+const SCEV* ScalarEvolution::HowFarToNonZero(const SCEV *V, const Loop *L) {
// Loops that look like: while (X == 0) are very strange indeed. We don't
// handle them yet except for the trivial case. This could be expanded in the
// future as needed.
/// more general, since a front-end may have replicated the controlling
/// expression.
///
-static bool HasSameValue(const SCEVHandle &A, const SCEVHandle &B) {
+static bool HasSameValue(const SCEV* A, const SCEV* B) {
// Quick check to see if they are the same SCEV.
if (A == B) return true;
LoopEntryPredicate->isUnconditional())
continue;
- ICmpInst *ICI = dyn_cast<ICmpInst>(LoopEntryPredicate->getCondition());
- if (!ICI) continue;
+ if (isNecessaryCond(LoopEntryPredicate->getCondition(), Pred, LHS, RHS,
+ LoopEntryPredicate->getSuccessor(0) != PredecessorDest))
+ return true;
+ }
- // Now that we found a conditional branch that dominates the loop, check to
- // see if it is the comparison we are looking for.
- Value *PreCondLHS = ICI->getOperand(0);
- Value *PreCondRHS = ICI->getOperand(1);
- ICmpInst::Predicate Cond;
- if (LoopEntryPredicate->getSuccessor(0) == PredecessorDest)
- Cond = ICI->getPredicate();
- else
- Cond = ICI->getInversePredicate();
+ return false;
+}
- if (Cond == Pred)
- ; // An exact match.
- else if (!ICmpInst::isTrueWhenEqual(Cond) && Pred == ICmpInst::ICMP_NE)
- ; // The actual condition is beyond sufficient.
- else
- // Check a few special cases.
- switch (Cond) {
- case ICmpInst::ICMP_UGT:
- if (Pred == ICmpInst::ICMP_ULT) {
- std::swap(PreCondLHS, PreCondRHS);
- Cond = ICmpInst::ICMP_ULT;
- break;
- }
- continue;
- case ICmpInst::ICMP_SGT:
- if (Pred == ICmpInst::ICMP_SLT) {
- std::swap(PreCondLHS, PreCondRHS);
- Cond = ICmpInst::ICMP_SLT;
+/// isNecessaryCond - Test whether the given CondValue value is a condition
+/// which is at least as strict as the one described by Pred, LHS, and RHS.
+bool ScalarEvolution::isNecessaryCond(Value *CondValue,
+ ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS,
+ bool Inverse) {
+ // Recursivly handle And and Or conditions.
+ if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CondValue)) {
+ if (BO->getOpcode() == Instruction::And) {
+ if (!Inverse)
+ return isNecessaryCond(BO->getOperand(0), Pred, LHS, RHS, Inverse) ||
+ isNecessaryCond(BO->getOperand(1), Pred, LHS, RHS, Inverse);
+ } else if (BO->getOpcode() == Instruction::Or) {
+ if (Inverse)
+ return isNecessaryCond(BO->getOperand(0), Pred, LHS, RHS, Inverse) ||
+ isNecessaryCond(BO->getOperand(1), Pred, LHS, RHS, Inverse);
+ }
+ }
+
+ ICmpInst *ICI = dyn_cast<ICmpInst>(CondValue);
+ if (!ICI) return false;
+
+ // Now that we found a conditional branch that dominates the loop, check to
+ // see if it is the comparison we are looking for.
+ Value *PreCondLHS = ICI->getOperand(0);
+ Value *PreCondRHS = ICI->getOperand(1);
+ ICmpInst::Predicate Cond;
+ if (Inverse)
+ Cond = ICI->getInversePredicate();
+ else
+ Cond = ICI->getPredicate();
+
+ if (Cond == Pred)
+ ; // An exact match.
+ else if (!ICmpInst::isTrueWhenEqual(Cond) && Pred == ICmpInst::ICMP_NE)
+ ; // The actual condition is beyond sufficient.
+ else
+ // Check a few special cases.
+ switch (Cond) {
+ case ICmpInst::ICMP_UGT:
+ if (Pred == ICmpInst::ICMP_ULT) {
+ std::swap(PreCondLHS, PreCondRHS);
+ Cond = ICmpInst::ICMP_ULT;
+ break;
+ }
+ return false;
+ case ICmpInst::ICMP_SGT:
+ if (Pred == ICmpInst::ICMP_SLT) {
+ std::swap(PreCondLHS, PreCondRHS);
+ Cond = ICmpInst::ICMP_SLT;
+ break;
+ }
+ return false;
+ case ICmpInst::ICMP_NE:
+ // Expressions like (x >u 0) are often canonicalized to (x != 0),
+ // so check for this case by checking if the NE is comparing against
+ // a minimum or maximum constant.
+ if (!ICmpInst::isTrueWhenEqual(Pred))
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(PreCondRHS)) {
+ const APInt &A = CI->getValue();
+ switch (Pred) {
+ case ICmpInst::ICMP_SLT:
+ if (A.isMaxSignedValue()) break;
+ return false;
+ case ICmpInst::ICMP_SGT:
+ if (A.isMinSignedValue()) break;
+ return false;
+ case ICmpInst::ICMP_ULT:
+ if (A.isMaxValue()) break;
+ return false;
+ case ICmpInst::ICMP_UGT:
+ if (A.isMinValue()) break;
+ return false;
+ default:
+ return false;
+ }
+ Cond = ICmpInst::ICMP_NE;
+ // NE is symmetric but the original comparison may not be. Swap
+ // the operands if necessary so that they match below.
+ if (isa<SCEVConstant>(LHS))
+ std::swap(PreCondLHS, PreCondRHS);
break;
}
- continue;
- case ICmpInst::ICMP_NE:
- // Expressions like (x >u 0) are often canonicalized to (x != 0),
- // so check for this case by checking if the NE is comparing against
- // a minimum or maximum constant.
- if (!ICmpInst::isTrueWhenEqual(Pred))
- if (ConstantInt *CI = dyn_cast<ConstantInt>(PreCondRHS)) {
- const APInt &A = CI->getValue();
- switch (Pred) {
- case ICmpInst::ICMP_SLT:
- if (A.isMaxSignedValue()) break;
- continue;
- case ICmpInst::ICMP_SGT:
- if (A.isMinSignedValue()) break;
- continue;
- case ICmpInst::ICMP_ULT:
- if (A.isMaxValue()) break;
- continue;
- case ICmpInst::ICMP_UGT:
- if (A.isMinValue()) break;
- continue;
- default:
- continue;
- }
- Cond = ICmpInst::ICMP_NE;
- // NE is symmetric but the original comparison may not be. Swap
- // the operands if necessary so that they match below.
- if (isa<SCEVConstant>(LHS))
- std::swap(PreCondLHS, PreCondRHS);
- break;
- }
- continue;
- default:
- // We weren't able to reconcile the condition.
- continue;
- }
+ return false;
+ default:
+ // We weren't able to reconcile the condition.
+ return false;
+ }
- if (!PreCondLHS->getType()->isInteger()) continue;
+ if (!PreCondLHS->getType()->isInteger()) return false;
- SCEVHandle PreCondLHSSCEV = getSCEV(PreCondLHS);
- SCEVHandle PreCondRHSSCEV = getSCEV(PreCondRHS);
- if ((HasSameValue(LHS, PreCondLHSSCEV) &&
- HasSameValue(RHS, PreCondRHSSCEV)) ||
- (HasSameValue(LHS, getNotSCEV(PreCondRHSSCEV)) &&
- HasSameValue(RHS, getNotSCEV(PreCondLHSSCEV))))
- return true;
- }
-
- return false;
+ const SCEV *PreCondLHSSCEV = getSCEV(PreCondLHS);
+ const SCEV *PreCondRHSSCEV = getSCEV(PreCondRHS);
+ return (HasSameValue(LHS, PreCondLHSSCEV) &&
+ HasSameValue(RHS, PreCondRHSSCEV)) ||
+ (HasSameValue(LHS, getNotSCEV(PreCondRHSSCEV)) &&
+ HasSameValue(RHS, getNotSCEV(PreCondLHSSCEV)));
}
/// getBECount - Subtract the end and start values and divide by the step,
/// rounding up, to get the number of times the backedge is executed. Return
/// CouldNotCompute if an intermediate computation overflows.
-SCEVHandle ScalarEvolution::getBECount(const SCEVHandle &Start,
- const SCEVHandle &End,
- const SCEVHandle &Step) {
+const SCEV* ScalarEvolution::getBECount(const SCEV* Start,
+ const SCEV* End,
+ const SCEV* Step) {
const Type *Ty = Start->getType();
- SCEVHandle NegOne = getIntegerSCEV(-1, Ty);
- SCEVHandle Diff = getMinusSCEV(End, Start);
- SCEVHandle RoundUp = getAddExpr(Step, NegOne);
+ const SCEV* NegOne = getIntegerSCEV(-1, Ty);
+ const SCEV* Diff = getMinusSCEV(End, Start);
+ const SCEV* RoundUp = getAddExpr(Step, NegOne);
// Add an adjustment to the difference between End and Start so that
// the division will effectively round up.
- SCEVHandle Add = getAddExpr(Diff, RoundUp);
+ const SCEV* Add = getAddExpr(Diff, RoundUp);
// Check Add for unsigned overflow.
// TODO: More sophisticated things could be done here.
const Type *WideTy = IntegerType::get(getTypeSizeInBits(Ty) + 1);
- SCEVHandle OperandExtendedAdd =
+ const SCEV* OperandExtendedAdd =
getAddExpr(getZeroExtendExpr(Diff, WideTy),
getZeroExtendExpr(RoundUp, WideTy));
if (getZeroExtendExpr(Add, WideTy) != OperandExtendedAdd)
if (AddRec->isAffine()) {
// FORNOW: We only support unit strides.
unsigned BitWidth = getTypeSizeInBits(AddRec->getType());
- SCEVHandle Step = AddRec->getStepRecurrence(*this);
+ const SCEV* Step = AddRec->getStepRecurrence(*this);
// TODO: handle non-constant strides.
const SCEVConstant *CStep = dyn_cast<SCEVConstant>(Step);
// treat m-n as signed nor unsigned due to overflow possibility.
// First, we get the value of the LHS in the first iteration: n
- SCEVHandle Start = AddRec->getOperand(0);
+ const SCEV* Start = AddRec->getOperand(0);
// Determine the minimum constant start value.
- SCEVHandle MinStart = isa<SCEVConstant>(Start) ? Start :
+ const SCEV* MinStart = isa<SCEVConstant>(Start) ? Start :
getConstant(isSigned ? APInt::getSignedMinValue(BitWidth) :
APInt::getMinValue(BitWidth));
// then we know that it will run exactly (m-n)/s times. Otherwise, we
// only know that it will execute (max(m,n)-n)/s times. In both cases,
// the division must round up.
- SCEVHandle End = RHS;
+ const SCEV* End = RHS;
if (!isLoopGuardedByCond(L,
isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
getMinusSCEV(Start, Step), RHS))
: getUMaxExpr(RHS, Start);
// Determine the maximum constant end value.
- SCEVHandle MaxEnd =
+ const SCEV* MaxEnd =
isa<SCEVConstant>(End) ? End :
getConstant(isSigned ? APInt::getSignedMaxValue(BitWidth)
.ashr(GetMinSignBits(End) - 1) :
// Finally, we subtract these two values and divide, rounding up, to get
// the number of times the backedge is executed.
- SCEVHandle BECount = getBECount(Start, End, Step);
+ const SCEV* BECount = getBECount(Start, End, Step);
// The maximum backedge count is similar, except using the minimum start
// value and the maximum end value.
- SCEVHandle MaxBECount = getBECount(MinStart, MaxEnd, Step);;
+ const SCEV* MaxBECount = getBECount(MinStart, MaxEnd, Step);;
return BackedgeTakenInfo(BECount, MaxBECount);
}
/// this is that it returns the first iteration number where the value is not in
/// the condition, thus computing the exit count. If the iteration count can't
/// be computed, an instance of SCEVCouldNotCompute is returned.
-SCEVHandle SCEVAddRecExpr::getNumIterationsInRange(ConstantRange Range,
+const SCEV* SCEVAddRecExpr::getNumIterationsInRange(ConstantRange Range,
ScalarEvolution &SE) const {
if (Range.isFullSet()) // Infinite loop.
return SE.getCouldNotCompute();
// If the start is a non-zero constant, shift the range to simplify things.
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(getStart()))
if (!SC->getValue()->isZero()) {
- SmallVector<SCEVHandle, 4> Operands(op_begin(), op_end());
+ SmallVector<const SCEV*, 4> Operands(op_begin(), op_end());
Operands[0] = SE.getIntegerSCEV(0, SC->getType());
- SCEVHandle Shifted = SE.getAddRecExpr(Operands, getLoop());
+ const SCEV* Shifted = SE.getAddRecExpr(Operands, getLoop());
if (const SCEVAddRecExpr *ShiftedAddRec =
dyn_cast<SCEVAddRecExpr>(Shifted))
return ShiftedAddRec->getNumIterationsInRange(
// quadratic equation to solve it. To do this, we must frame our problem in
// terms of figuring out when zero is crossed, instead of when
// Range.getUpper() is crossed.
- SmallVector<SCEVHandle, 4> NewOps(op_begin(), op_end());
+ SmallVector<const SCEV*, 4> NewOps(op_begin(), op_end());
NewOps[0] = SE.getNegativeSCEV(SE.getConstant(Range.getUpper()));
- SCEVHandle NewAddRec = SE.getAddRecExpr(NewOps, getLoop());
+ const SCEV* NewAddRec = SE.getAddRecExpr(NewOps, getLoop());
// Next, solve the constructed addrec
- std::pair<SCEVHandle,SCEVHandle> Roots =
+ std::pair<const SCEV*,const SCEV*> Roots =
SolveQuadraticEquation(cast<SCEVAddRecExpr>(NewAddRec), SE);
const SCEVConstant *R1 = dyn_cast<SCEVConstant>(Roots.first);
const SCEVConstant *R2 = dyn_cast<SCEVConstant>(Roots.second);
//===----------------------------------------------------------------------===//
ScalarEvolution::ScalarEvolution()
- : FunctionPass(&ID), CouldNotCompute(new SCEVCouldNotCompute(0)) {
+ : FunctionPass(&ID), CouldNotCompute(new SCEVCouldNotCompute()) {
}
bool ScalarEvolution::runOnFunction(Function &F) {
OS << "Unpredictable backedge-taken count. ";
}
+ OS << "\n";
+ OS << "Loop " << L->getHeader()->getName() << ": ";
+
+ if (!isa<SCEVCouldNotCompute>(SE->getMaxBackedgeTakenCount(L))) {
+ OS << "max backedge-taken count is " << *SE->getMaxBackedgeTakenCount(L);
+ } else {
+ OS << "Unpredictable max backedge-taken count. ";
+ }
+
OS << "\n";
}
if (isSCEVable(I->getType())) {
OS << *I;
OS << " --> ";
- SCEVHandle SV = SE.getSCEV(&*I);
+ const SCEV* SV = SE.getSCEV(&*I);
SV->print(OS);
const Loop *L = LI->getLoopFor((*I).getParent());
- SCEVHandle AtUse = SE.getSCEVAtScope(SV, L);
+ const SCEV* AtUse = SE.getSCEVAtScope(SV, L);
if (AtUse != SV) {
OS << " --> ";
AtUse->print(OS);
if (L) {
OS << "\t\t" "Exits: ";
- SCEVHandle ExitValue = SE.getSCEVAtScope(SV, L->getParentLoop());
+ const SCEV* ExitValue = SE.getSCEVAtScope(SV, L->getParentLoop());
if (!ExitValue->isLoopInvariant(L)) {
OS << "<<Unknown>>";
} else {
projects / oota-llvm.git / blobdiff