"derived loop"),
cl::init(100));
-static RegisterPass<ScalarEvolution>
-R("scalar-evolution", "Scalar Evolution Analysis", false, true);
+INITIALIZE_PASS(ScalarEvolution, "scalar-evolution",
+ "Scalar Evolution Analysis", false, true);
char ScalarEvolution::ID = 0;
//===----------------------------------------------------------------------===//
}
SCEVCouldNotCompute::SCEVCouldNotCompute() :
- SCEV(FoldingSetNodeID(), scCouldNotCompute) {}
+ SCEV(FoldingSetNodeIDRef(), scCouldNotCompute) {}
bool SCEVCouldNotCompute::isLoopInvariant(const Loop *L) const {
llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
ID.AddPointer(V);
void *IP = 0;
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVConstant>();
- new (S) SCEVConstant(ID, V);
+ SCEV *S = new (SCEVAllocator) SCEVConstant(ID.Intern(SCEVAllocator), V);
UniqueSCEVs.InsertNode(S, IP);
return S;
}
const SCEV *
ScalarEvolution::getConstant(const Type *Ty, uint64_t V, bool isSigned) {
- return getConstant(
- ConstantInt::get(cast<IntegerType>(Ty), V, isSigned));
+ const IntegerType *ITy = cast<IntegerType>(getEffectiveSCEVType(Ty));
+ return getConstant(ConstantInt::get(ITy, V, isSigned));
}
const Type *SCEVConstant::getType() const { return V->getType(); }
WriteAsOperand(OS, V, false);
}
-SCEVCastExpr::SCEVCastExpr(const FoldingSetNodeID &ID,
+SCEVCastExpr::SCEVCastExpr(const FoldingSetNodeIDRef ID,
unsigned SCEVTy, const SCEV *op, const Type *ty)
: SCEV(ID, SCEVTy), Op(op), Ty(ty) {}
return Op->properlyDominates(BB, DT);
}
-SCEVTruncateExpr::SCEVTruncateExpr(const FoldingSetNodeID &ID,
+SCEVTruncateExpr::SCEVTruncateExpr(const FoldingSetNodeIDRef ID,
const SCEV *op, const Type *ty)
: SCEVCastExpr(ID, scTruncate, op, ty) {
- assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((Op->getType()->isIntegerTy() || Op->getType()->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot truncate non-integer value!");
}
OS << "(trunc " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
}
-SCEVZeroExtendExpr::SCEVZeroExtendExpr(const FoldingSetNodeID &ID,
+SCEVZeroExtendExpr::SCEVZeroExtendExpr(const FoldingSetNodeIDRef ID,
const SCEV *op, const Type *ty)
: SCEVCastExpr(ID, scZeroExtend, op, ty) {
- assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((Op->getType()->isIntegerTy() || Op->getType()->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot zero extend non-integer value!");
}
OS << "(zext " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
}
-SCEVSignExtendExpr::SCEVSignExtendExpr(const FoldingSetNodeID &ID,
+SCEVSignExtendExpr::SCEVSignExtendExpr(const FoldingSetNodeIDRef ID,
const SCEV *op, const Type *ty)
: SCEVCastExpr(ID, scSignExtend, op, ty) {
- assert((Op->getType()->isInteger() || isa<PointerType>(Op->getType())) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((Op->getType()->isIntegerTy() || Op->getType()->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot sign extend non-integer value!");
}
}
void SCEVCommutativeExpr::print(raw_ostream &OS) const {
- assert(Operands.size() > 1 && "This plus expr shouldn't exist!");
const char *OpStr = getOperationStr();
- OS << "(" << *Operands[0];
- for (unsigned i = 1, e = Operands.size(); i != e; ++i)
- OS << OpStr << *Operands[i];
+ OS << "(";
+ for (op_iterator I = op_begin(), E = op_end(); I != E; ++I) {
+ OS << **I;
+ if (next(I) != E)
+ OS << OpStr;
+ }
OS << ")";
}
return true;
}
+bool
+SCEVAddRecExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
+ return DT->dominates(L->getHeader(), BB) &&
+ SCEVNAryExpr::dominates(BB, DT);
+}
+
+bool
+SCEVAddRecExpr::properlyDominates(BasicBlock *BB, DominatorTree *DT) const {
+ // This uses a "dominates" query instead of "properly dominates" query because
+ // the instruction which produces the addrec's value is a PHI, and a PHI
+ // effectively properly dominates its entire containing block.
+ return DT->dominates(L->getHeader(), BB) &&
+ SCEVNAryExpr::properlyDominates(BB, DT);
+}
+
void SCEVAddRecExpr::print(raw_ostream &OS) const {
OS << "{" << *Operands[0];
- for (unsigned i = 1, e = Operands.size(); i != e; ++i)
+ for (unsigned i = 1, e = NumOperands; i != e; ++i)
OS << ",+," << *Operands[i];
OS << "}<";
WriteAsOperand(OS, L->getHeader(), /*PrintType=*/false);
OS << ">";
}
-void SCEVFieldOffsetExpr::print(raw_ostream &OS) const {
- // LLVM struct fields don't have names, so just print the field number.
- OS << "offsetof(" << *STy << ", " << FieldNo << ")";
-}
-
-void SCEVAllocSizeExpr::print(raw_ostream &OS) const {
- OS << "sizeof(" << *AllocTy << ")";
-}
-
bool SCEVUnknown::isLoopInvariant(const Loop *L) const {
// All non-instruction values are loop invariant. All instructions are loop
// invariant if they are not contained in the specified loop.
return V->getType();
}
+bool SCEVUnknown::isSizeOf(const Type *&AllocTy) const {
+ if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(V))
+ if (VCE->getOpcode() == Instruction::PtrToInt)
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(VCE->getOperand(0)))
+ if (CE->getOpcode() == Instruction::GetElementPtr &&
+ CE->getOperand(0)->isNullValue() &&
+ CE->getNumOperands() == 2)
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(1)))
+ if (CI->isOne()) {
+ AllocTy = cast<PointerType>(CE->getOperand(0)->getType())
+ ->getElementType();
+ return true;
+ }
+
+ return false;
+}
+
+bool SCEVUnknown::isAlignOf(const Type *&AllocTy) const {
+ if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(V))
+ if (VCE->getOpcode() == Instruction::PtrToInt)
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(VCE->getOperand(0)))
+ if (CE->getOpcode() == Instruction::GetElementPtr &&
+ CE->getOperand(0)->isNullValue()) {
+ const Type *Ty =
+ cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+ if (const StructType *STy = dyn_cast<StructType>(Ty))
+ if (!STy->isPacked() &&
+ CE->getNumOperands() == 3 &&
+ CE->getOperand(1)->isNullValue()) {
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(2)))
+ if (CI->isOne() &&
+ STy->getNumElements() == 2 &&
+ STy->getElementType(0)->isIntegerTy(1)) {
+ AllocTy = STy->getElementType(1);
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+bool SCEVUnknown::isOffsetOf(const Type *&CTy, Constant *&FieldNo) const {
+ if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(V))
+ if (VCE->getOpcode() == Instruction::PtrToInt)
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(VCE->getOperand(0)))
+ if (CE->getOpcode() == Instruction::GetElementPtr &&
+ CE->getNumOperands() == 3 &&
+ CE->getOperand(0)->isNullValue() &&
+ CE->getOperand(1)->isNullValue()) {
+ const Type *Ty =
+ cast<PointerType>(CE->getOperand(0)->getType())->getElementType();
+ // Ignore vector types here so that ScalarEvolutionExpander doesn't
+ // emit getelementptrs that index into vectors.
+ if (Ty->isStructTy() || Ty->isArrayTy()) {
+ CTy = Ty;
+ FieldNo = CE->getOperand(2);
+ return true;
+ }
+ }
+
+ return false;
+}
+
void SCEVUnknown::print(raw_ostream &OS) const {
+ const Type *AllocTy;
+ if (isSizeOf(AllocTy)) {
+ OS << "sizeof(" << *AllocTy << ")";
+ return;
+ }
+ if (isAlignOf(AllocTy)) {
+ OS << "alignof(" << *AllocTy << ")";
+ return;
+ }
+
+ const Type *CTy;
+ Constant *FieldNo;
+ if (isOffsetOf(CTy, FieldNo)) {
+ OS << "offsetof(" << *CTy << ", ";
+ WriteAsOperand(OS, FieldNo, false);
+ OS << ")";
+ return;
+ }
+
+ // Otherwise just print it normally.
WriteAsOperand(OS, V, false);
}
// Order pointer values after integer values. This helps SCEVExpander
// form GEPs.
- if (isa<PointerType>(LU->getType()) && !isa<PointerType>(RU->getType()))
+ if (LU->getType()->isPointerTy() && !RU->getType()->isPointerTy())
return false;
- if (isa<PointerType>(RU->getType()) && !isa<PointerType>(LU->getType()))
+ if (RU->getType()->isPointerTy() && !LU->getType()->isPointerTy())
return true;
// Compare getValueID values.
return operator()(LC->getOperand(), RC->getOperand());
}
- // Compare offsetof expressions.
- if (const SCEVFieldOffsetExpr *LA = dyn_cast<SCEVFieldOffsetExpr>(LHS)) {
- const SCEVFieldOffsetExpr *RA = cast<SCEVFieldOffsetExpr>(RHS);
- if (CompareTypes(LA->getStructType(), RA->getStructType()) ||
- CompareTypes(RA->getStructType(), LA->getStructType()))
- return CompareTypes(LA->getStructType(), RA->getStructType());
- return LA->getFieldNo() < RA->getFieldNo();
- }
-
- // Compare sizeof expressions by the allocation type.
- if (const SCEVAllocSizeExpr *LA = dyn_cast<SCEVAllocSizeExpr>(LHS)) {
- const SCEVAllocSizeExpr *RA = cast<SCEVAllocSizeExpr>(RHS);
- return CompareTypes(LA->getAllocType(), RA->getAllocType());
- }
-
llvm_unreachable("Unknown SCEV kind!");
return false;
}
/// When this routine is finished, we know that any duplicates in the vector are
/// consecutive and that complexity is monotonically increasing.
///
-/// Note that we go take special precautions to ensure that we get determinstic
+/// Note that we go take special precautions to ensure that we get deterministic
/// results from this routine. In other words, we don't want the results of
/// this to depend on where the addresses of various SCEV objects happened to
/// land in memory.
// We need at least W + T bits for the multiplication step
unsigned CalculationBits = W + T;
- // Calcuate 2^T, at width T+W.
+ // Calculate 2^T, at width T+W.
APInt DivFactor = APInt(CalculationBits, 1).shl(T);
// Calculate the multiplicative inverse of K! / 2^T;
CalculationBits);
const SCEV *Dividend = SE.getTruncateOrZeroExtend(It, CalculationTy);
for (unsigned i = 1; i != K; ++i) {
- const SCEV *S = SE.getMinusSCEV(It, SE.getIntegerSCEV(i, It->getType()));
+ const SCEV *S = SE.getMinusSCEV(It, SE.getConstant(It->getType(), i));
Dividend = SE.getMulExpr(Dividend,
SE.getTruncateOrZeroExtend(S, CalculationTy));
}
// Fold if the operand is constant.
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op))
return getConstant(
- cast<ConstantInt>(ConstantExpr::getTrunc(SC->getValue(), Ty)));
+ cast<ConstantInt>(ConstantExpr::getTrunc(SC->getValue(),
+ getEffectiveSCEVType(Ty))));
// trunc(trunc(x)) --> trunc(x)
if (const SCEVTruncateExpr *ST = dyn_cast<SCEVTruncateExpr>(Op))
return getAddRecExpr(Operands, AddRec->getLoop());
}
- // The cast wasn't folded; create an explicit cast node.
- // Recompute the insert position, as it may have been invalidated.
- if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVTruncateExpr>();
- new (S) SCEVTruncateExpr(ID, Op, Ty);
+ // As a special case, fold trunc(undef) to undef. We don't want to
+ // know too much about SCEVUnknowns, but this special case is handy
+ // and harmless.
+ if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Op))
+ if (isa<UndefValue>(U->getValue()))
+ return getSCEV(UndefValue::get(Ty));
+
+ // The cast wasn't folded; create an explicit cast node. We can reuse
+ // the existing insert position since if we get here, we won't have
+ // made any changes which would invalidate it.
+ SCEV *S = new (SCEVAllocator) SCEVTruncateExpr(ID.Intern(SCEVAllocator),
+ Op, Ty);
UniqueSCEVs.InsertNode(S, IP);
return S;
}
Ty = getEffectiveSCEVType(Ty);
// Fold if the operand is constant.
- if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op)) {
- const Type *IntTy = getEffectiveSCEVType(Ty);
- Constant *C = ConstantExpr::getZExt(SC->getValue(), IntTy);
- if (IntTy != Ty) C = ConstantExpr::getIntToPtr(C, Ty);
- return getConstant(cast<ConstantInt>(C));
- }
+ if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op))
+ return getConstant(
+ cast<ConstantInt>(ConstantExpr::getZExt(SC->getValue(),
+ getEffectiveSCEVType(Ty))));
// zext(zext(x)) --> zext(x)
if (const SCEVZeroExtendExpr *SZ = dyn_cast<SCEVZeroExtendExpr>(Op))
if (MaxBECount == RecastedMaxBECount) {
const Type *WideTy = IntegerType::get(getContext(), BitWidth * 2);
// Check whether Start+Step*MaxBECount has no unsigned overflow.
- const SCEV *ZMul =
- getMulExpr(CastedMaxBECount,
- getTruncateOrZeroExtend(Step, Start->getType()));
+ const SCEV *ZMul = getMulExpr(CastedMaxBECount, Step);
const SCEV *Add = getAddExpr(Start, ZMul);
const SCEV *OperandExtendedAdd =
getAddExpr(getZeroExtendExpr(Start, WideTy),
// Similar to above, only this time treat the step value as signed.
// This covers loops that count down.
- const SCEV *SMul =
- getMulExpr(CastedMaxBECount,
- getTruncateOrSignExtend(Step, Start->getType()));
+ const SCEV *SMul = getMulExpr(CastedMaxBECount, Step);
Add = getAddExpr(Start, SMul);
OperandExtendedAdd =
getAddExpr(getZeroExtendExpr(Start, WideTy),
const SCEV *N = getConstant(APInt::getMinValue(BitWidth) -
getUnsignedRange(Step).getUnsignedMax());
if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_ULT, AR, N) ||
- (isLoopGuardedByCond(L, ICmpInst::ICMP_ULT, Start, N) &&
+ (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_ULT, Start, N) &&
isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_ULT,
AR->getPostIncExpr(*this), N)))
// Return the expression with the addrec on the outside.
} else if (isKnownNegative(Step)) {
const SCEV *N = getConstant(APInt::getMaxValue(BitWidth) -
getSignedRange(Step).getSignedMin());
- if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT, AR, N) &&
- (isLoopGuardedByCond(L, ICmpInst::ICMP_UGT, Start, N) ||
+ if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT, AR, N) ||
+ (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_UGT, Start, N) &&
isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_UGT,
AR->getPostIncExpr(*this), N)))
// Return the expression with the addrec on the outside.
// The cast wasn't folded; create an explicit cast node.
// Recompute the insert position, as it may have been invalidated.
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVZeroExtendExpr>();
- new (S) SCEVZeroExtendExpr(ID, Op, Ty);
+ SCEV *S = new (SCEVAllocator) SCEVZeroExtendExpr(ID.Intern(SCEVAllocator),
+ Op, Ty);
UniqueSCEVs.InsertNode(S, IP);
return S;
}
Ty = getEffectiveSCEVType(Ty);
// Fold if the operand is constant.
- if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op)) {
- const Type *IntTy = getEffectiveSCEVType(Ty);
- Constant *C = ConstantExpr::getSExt(SC->getValue(), IntTy);
- if (IntTy != Ty) C = ConstantExpr::getIntToPtr(C, Ty);
- return getConstant(cast<ConstantInt>(C));
- }
+ if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(Op))
+ return getConstant(
+ cast<ConstantInt>(ConstantExpr::getSExt(SC->getValue(),
+ getEffectiveSCEVType(Ty))));
// sext(sext(x)) --> sext(x)
if (const SCEVSignExtendExpr *SS = dyn_cast<SCEVSignExtendExpr>(Op))
if (MaxBECount == RecastedMaxBECount) {
const Type *WideTy = IntegerType::get(getContext(), BitWidth * 2);
// Check whether Start+Step*MaxBECount has no signed overflow.
- const SCEV *SMul =
- getMulExpr(CastedMaxBECount,
- getTruncateOrSignExtend(Step, Start->getType()));
+ const SCEV *SMul = getMulExpr(CastedMaxBECount, Step);
const SCEV *Add = getAddExpr(Start, SMul);
const SCEV *OperandExtendedAdd =
getAddExpr(getSignExtendExpr(Start, WideTy),
// Similar to above, only this time treat the step value as unsigned.
// This covers loops that count up with an unsigned step.
- const SCEV *UMul =
- getMulExpr(CastedMaxBECount,
- getTruncateOrZeroExtend(Step, Start->getType()));
+ const SCEV *UMul = getMulExpr(CastedMaxBECount, Step);
Add = getAddExpr(Start, UMul);
OperandExtendedAdd =
getAddExpr(getSignExtendExpr(Start, WideTy),
const SCEV *N = getConstant(APInt::getSignedMinValue(BitWidth) -
getSignedRange(Step).getSignedMax());
if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SLT, AR, N) ||
- (isLoopGuardedByCond(L, ICmpInst::ICMP_SLT, Start, N) &&
+ (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SLT, Start, N) &&
isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SLT,
AR->getPostIncExpr(*this), N)))
// Return the expression with the addrec on the outside.
const SCEV *N = getConstant(APInt::getSignedMaxValue(BitWidth) -
getSignedRange(Step).getSignedMin());
if (isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SGT, AR, N) ||
- (isLoopGuardedByCond(L, ICmpInst::ICMP_SGT, Start, N) &&
+ (isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SGT, Start, N) &&
isLoopBackedgeGuardedByCond(L, ICmpInst::ICMP_SGT,
AR->getPostIncExpr(*this), N)))
// Return the expression with the addrec on the outside.
// The cast wasn't folded; create an explicit cast node.
// Recompute the insert position, as it may have been invalidated.
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVSignExtendExpr>();
- new (S) SCEVSignExtendExpr(ID, Op, Ty);
+ SCEV *S = new (SCEVAllocator) SCEVSignExtendExpr(ID.Intern(SCEVAllocator),
+ Op, Ty);
UniqueSCEVs.InsertNode(S, IP);
return S;
}
return getAddRecExpr(Ops, AR->getLoop());
}
+ // As a special case, fold anyext(undef) to undef. We don't want to
+ // know too much about SCEVUnknowns, but this special case is handy
+ // and harmless.
+ if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Op))
+ if (isa<UndefValue>(U->getValue()))
+ return getSCEV(UndefValue::get(Ty));
+
// If the expression is obviously signed, use the sext cast value.
if (isa<SCEVSMaxExpr>(Op))
return SExt;
CollectAddOperandsWithScales(DenseMap<const SCEV *, APInt> &M,
SmallVector<const SCEV *, 8> &NewOps,
APInt &AccumulatedConstant,
- const SmallVectorImpl<const SCEV *> &Ops,
+ const SCEV *const *Ops, size_t NumOperands,
const APInt &Scale,
ScalarEvolution &SE) {
bool Interesting = false;
- // Iterate over the add operands.
- for (unsigned i = 0, e = Ops.size(); i != e; ++i) {
+ // Iterate over the add operands. They are sorted, with constants first.
+ unsigned i = 0;
+ while (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[i])) {
+ ++i;
+ // Pull a buried constant out to the outside.
+ if (Scale != 1 || AccumulatedConstant != 0 || C->getValue()->isZero())
+ Interesting = true;
+ AccumulatedConstant += Scale * C->getValue()->getValue();
+ }
+
+ // Next comes everything else. We're especially interested in multiplies
+ // here, but they're in the middle, so just visit the rest with one loop.
+ for (; i != NumOperands; ++i) {
const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(Ops[i]);
if (Mul && isa<SCEVConstant>(Mul->getOperand(0))) {
APInt NewScale =
Scale * cast<SCEVConstant>(Mul->getOperand(0))->getValue()->getValue();
if (Mul->getNumOperands() == 2 && isa<SCEVAddExpr>(Mul->getOperand(1))) {
// A multiplication of a constant with another add; recurse.
+ const SCEVAddExpr *Add = cast<SCEVAddExpr>(Mul->getOperand(1));
Interesting |=
CollectAddOperandsWithScales(M, NewOps, AccumulatedConstant,
- cast<SCEVAddExpr>(Mul->getOperand(1))
- ->getOperands(),
+ Add->op_begin(), Add->getNumOperands(),
NewScale, SE);
} else {
// A multiplication of a constant with some other value. Update
Interesting = true;
}
}
- } else if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[i])) {
- // Pull a buried constant out to the outside.
- if (Scale != 1 || AccumulatedConstant != 0 || C->isZero())
- Interesting = true;
- AccumulatedConstant += Scale * C->getValue()->getValue();
} else {
// An ordinary operand. Update the map.
std::pair<DenseMap<const SCEV *, APInt>::iterator, bool> Pair =
assert(!Ops.empty() && "Cannot get empty add!");
if (Ops.size() == 1) return Ops[0];
#ifndef NDEBUG
+ const Type *ETy = getEffectiveSCEVType(Ops[0]->getType());
for (unsigned i = 1, e = Ops.size(); i != e; ++i)
- assert(getEffectiveSCEVType(Ops[i]->getType()) ==
- getEffectiveSCEVType(Ops[0]->getType()) &&
+ assert(getEffectiveSCEVType(Ops[i]->getType()) == ETy &&
"SCEVAddExpr operand types don't match!");
#endif
}
// If we are left with a constant zero being added, strip it off.
- if (cast<SCEVConstant>(Ops[0])->getValue()->isZero()) {
+ if (LHSC->getValue()->isZero()) {
Ops.erase(Ops.begin());
--Idx;
}
- }
- if (Ops.size() == 1) return Ops[0];
+ if (Ops.size() == 1) return Ops[0];
+ }
// Okay, check to see if the same value occurs in the operand list twice. If
// so, merge them together into an multiply expression. Since we sorted the
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.
- const SCEV *Two = getIntegerSCEV(2, Ty);
+ const SCEV *Two = getConstant(Ty, 2);
const SCEV *Mul = getMulExpr(Ops[i], Two);
if (Ops.size() == 2)
return Mul;
}
LargeOps.push_back(T->getOperand());
} else if (const SCEVConstant *C = dyn_cast<SCEVConstant>(Ops[i])) {
- // This could be either sign or zero extension, but sign extension
- // is much more likely to be foldable here.
- LargeOps.push_back(getSignExtendExpr(C, SrcType));
+ LargeOps.push_back(getAnyExtendExpr(C, SrcType));
} else if (const SCEVMulExpr *M = dyn_cast<SCEVMulExpr>(Ops[i])) {
SmallVector<const SCEV *, 8> LargeMulOps;
for (unsigned j = 0, f = M->getNumOperands(); j != f && Ok; ++j) {
LargeMulOps.push_back(T->getOperand());
} else if (const SCEVConstant *C =
dyn_cast<SCEVConstant>(M->getOperand(j))) {
- // This could be either sign or zero extension, but sign extension
- // is much more likely to be foldable here.
- LargeMulOps.push_back(getSignExtendExpr(C, SrcType));
+ LargeMulOps.push_back(getAnyExtendExpr(C, SrcType));
} else {
Ok = false;
break;
while (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Ops[Idx])) {
// If we have an add, expand the add operands onto the end of the operands
// list.
- Ops.insert(Ops.end(), Add->op_begin(), Add->op_end());
Ops.erase(Ops.begin()+Idx);
+ Ops.append(Add->op_begin(), Add->op_end());
DeletedAdd = true;
}
// If we deleted at least one add, we added operands to the end of the list,
// and they are not necessarily sorted. Recurse to resort and resimplify
- // any operands we just aquired.
+ // any operands we just acquired.
if (DeletedAdd)
return getAddExpr(Ops);
}
SmallVector<const SCEV *, 8> NewOps;
APInt AccumulatedConstant(BitWidth, 0);
if (CollectAddOperandsWithScales(M, NewOps, AccumulatedConstant,
- Ops, APInt(BitWidth, 1), *this)) {
+ Ops.data(), Ops.size(),
+ 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.
Ops.push_back(getMulExpr(getConstant(I->first),
getAddExpr(I->second)));
if (Ops.empty())
- return getIntegerSCEV(0, Ty);
+ return getConstant(Ty, 0);
if (Ops.size() == 1)
return Ops[0];
return getAddExpr(Ops);
MulOps.erase(MulOps.begin()+MulOp);
InnerMul = getMulExpr(MulOps);
}
- const SCEV *One = getIntegerSCEV(1, Ty);
+ const SCEV *One = getConstant(Ty, 1);
const SCEV *AddOne = getAddExpr(InnerMul, One);
const SCEV *OuterMul = getMulExpr(AddOne, Ops[AddOp]);
if (Ops.size() == 2) return OuterMul;
// they are loop invariant w.r.t. the recurrence.
SmallVector<const SCEV *, 8> LIOps;
const SCEVAddRecExpr *AddRec = cast<SCEVAddRecExpr>(Ops[Idx]);
+ const Loop *AddRecLoop = AddRec->getLoop();
for (unsigned i = 0, e = Ops.size(); i != e; ++i)
- if (Ops[i]->isLoopInvariant(AddRec->getLoop())) {
+ if (Ops[i]->isLoopInvariant(AddRecLoop)) {
LIOps.push_back(Ops[i]);
Ops.erase(Ops.begin()+i);
--i; --e;
AddRec->op_end());
AddRecOps[0] = getAddExpr(LIOps);
- // It's tempting to propagate NUW/NSW flags here, but nuw/nsw addition
- // is not associative so this isn't necessarily safe.
- const SCEV *NewRec = getAddRecExpr(AddRecOps, AddRec->getLoop());
+ // Build the new addrec. Propagate the NUW and NSW flags if both the
+ // outer add and the inner addrec are guaranteed to have no overflow.
+ const SCEV *NewRec = getAddRecExpr(AddRecOps, AddRecLoop,
+ HasNUW && AddRec->hasNoUnsignedWrap(),
+ HasNSW && AddRec->hasNoSignedWrap());
// If all of the other operands were loop invariant, we are done.
if (Ops.size() == 1) return NewRec;
OtherIdx < Ops.size() && isa<SCEVAddRecExpr>(Ops[OtherIdx]);++OtherIdx)
if (OtherIdx != Idx) {
const SCEVAddRecExpr *OtherAddRec = cast<SCEVAddRecExpr>(Ops[OtherIdx]);
- if (AddRec->getLoop() == OtherAddRec->getLoop()) {
+ if (AddRecLoop == OtherAddRec->getLoop()) {
// Other + {A,+,B} + {C,+,D} --> Other + {A+C,+,B+D}
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.append(OtherAddRec->op_begin()+i,
OtherAddRec->op_end());
break;
}
NewOps[i] = getAddExpr(NewOps[i], OtherAddRec->getOperand(i));
}
- const SCEV *NewAddRec = getAddRecExpr(NewOps, AddRec->getLoop());
+ const SCEV *NewAddRec = getAddRecExpr(NewOps, AddRecLoop);
if (Ops.size() == 2) return NewAddRec;
SCEVAddExpr *S =
static_cast<SCEVAddExpr *>(UniqueSCEVs.FindNodeOrInsertPos(ID, IP));
if (!S) {
- S = SCEVAllocator.Allocate<SCEVAddExpr>();
- new (S) SCEVAddExpr(ID, Ops);
+ const SCEV **O = SCEVAllocator.Allocate<const SCEV *>(Ops.size());
+ std::uninitialized_copy(Ops.begin(), Ops.end(), O);
+ S = new (SCEVAllocator) SCEVAddExpr(ID.Intern(SCEVAllocator),
+ O, Ops.size());
UniqueSCEVs.InsertNode(S, IP);
}
if (HasNUW) S->setHasNoUnsignedWrap(true);
return getAddExpr(NewOps);
}
}
+
+ if (Ops.size() == 1)
+ return Ops[0];
}
// Skip over the add expression until we get to a multiply.
while (Idx < Ops.size() && Ops[Idx]->getSCEVType() < scMulExpr)
++Idx;
- if (Ops.size() == 1)
- return Ops[0];
-
// If there are mul operands inline them all into this expression.
if (Idx < Ops.size()) {
bool DeletedMul = false;
while (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(Ops[Idx])) {
// If we have an mul, expand the mul operands onto the end of the operands
// list.
- Ops.insert(Ops.end(), Mul->op_begin(), Mul->op_end());
Ops.erase(Ops.begin()+Idx);
+ Ops.append(Mul->op_begin(), Mul->op_end());
DeletedMul = true;
}
// If we deleted at least one mul, we added operands to the end of the list,
// and they are not necessarily sorted. Recurse to resort and resimplify
- // any operands we just aquired.
+ // any operands we just acquired.
if (DeletedMul)
return getMulExpr(Ops);
}
// NLI * LI * {Start,+,Step} --> NLI * {LI*Start,+,LI*Step}
SmallVector<const SCEV *, 4> NewOps;
NewOps.reserve(AddRec->getNumOperands());
- if (LIOps.size() == 1) {
- const SCEV *Scale = LIOps[0];
- for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i)
- NewOps.push_back(getMulExpr(Scale, AddRec->getOperand(i)));
- } else {
- for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i) {
- SmallVector<const SCEV *, 4> MulOps(LIOps.begin(), LIOps.end());
- MulOps.push_back(AddRec->getOperand(i));
- NewOps.push_back(getMulExpr(MulOps));
- }
- }
+ const SCEV *Scale = getMulExpr(LIOps);
+ for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i)
+ NewOps.push_back(getMulExpr(Scale, AddRec->getOperand(i)));
- // It's tempting to propagate the NSW flag here, but nsw multiplication
- // is not associative so this isn't necessarily safe.
+ // Build the new addrec. Propagate the NUW and NSW flags if both the
+ // outer mul and the inner addrec are guaranteed to have no overflow.
const SCEV *NewRec = getAddRecExpr(NewOps, AddRec->getLoop(),
HasNUW && AddRec->hasNoUnsignedWrap(),
- /*HasNSW=*/false);
+ HasNSW && AddRec->hasNoSignedWrap());
// If all of the other operands were loop invariant, we are done.
if (Ops.size() == 1) return NewRec;
SCEVMulExpr *S =
static_cast<SCEVMulExpr *>(UniqueSCEVs.FindNodeOrInsertPos(ID, IP));
if (!S) {
- S = SCEVAllocator.Allocate<SCEVMulExpr>();
- new (S) SCEVMulExpr(ID, Ops);
+ const SCEV **O = SCEVAllocator.Allocate<const SCEV *>(Ops.size());
+ std::uninitialized_copy(Ops.begin(), Ops.end(), O);
+ S = new (SCEVAllocator) SCEVMulExpr(ID.Intern(SCEVAllocator),
+ O, Ops.size());
UniqueSCEVs.InsertNode(S, IP);
}
if (HasNUW) S->setHasNoUnsignedWrap(true);
if (const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS)) {
if (RHSC->getValue()->equalsInt(1))
return LHS; // X udiv 1 --> x
- if (RHSC->isZero())
- return getIntegerSCEV(0, LHS->getType()); // value is undefined
-
- // Determine if the division can be folded into the operands of
- // its operands.
- // TODO: Generalize this to non-constants by using known-bits information.
- const Type *Ty = LHS->getType();
- unsigned LZ = RHSC->getValue()->getValue().countLeadingZeros();
- unsigned MaxShiftAmt = getTypeSizeInBits(Ty) - LZ;
- // For non-power-of-two values, effectively round the value up to the
- // nearest power of two.
- if (!RHSC->getValue()->getValue().isPowerOf2())
- ++MaxShiftAmt;
- const IntegerType *ExtTy =
- IntegerType::get(getContext(), getTypeSizeInBits(Ty) + MaxShiftAmt);
- // {X,+,N}/C --> {X/C,+,N/C} if safe and N/C can be folded.
- if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(LHS))
- if (const SCEVConstant *Step =
- dyn_cast<SCEVConstant>(AR->getStepRecurrence(*this)))
- if (!Step->getValue()->getValue()
- .urem(RHSC->getValue()->getValue()) &&
- getZeroExtendExpr(AR, ExtTy) ==
- getAddRecExpr(getZeroExtendExpr(AR->getStart(), ExtTy),
- getZeroExtendExpr(Step, ExtTy),
- AR->getLoop())) {
- 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<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) {
- const SCEV *Op = M->getOperand(i);
- const SCEV *Div = getUDivExpr(Op, RHSC);
- if (!isa<SCEVUDivExpr>(Div) && getMulExpr(Div, RHSC) == Op) {
- const SmallVectorImpl<const SCEV *> &MOperands = M->getOperands();
- Operands = SmallVector<const SCEV *, 4>(MOperands.begin(),
- MOperands.end());
- Operands[i] = Div;
- return getMulExpr(Operands);
+ // If the denominator is zero, the result of the udiv is undefined. Don't
+ // try to analyze it, because the resolution chosen here may differ from
+ // the resolution chosen in other parts of the compiler.
+ if (!RHSC->getValue()->isZero()) {
+ // Determine if the division can be folded into the operands of
+ // its operands.
+ // TODO: Generalize this to non-constants by using known-bits information.
+ const Type *Ty = LHS->getType();
+ unsigned LZ = RHSC->getValue()->getValue().countLeadingZeros();
+ unsigned MaxShiftAmt = getTypeSizeInBits(Ty) - LZ;
+ // For non-power-of-two values, effectively round the value up to the
+ // nearest power of two.
+ if (!RHSC->getValue()->getValue().isPowerOf2())
+ ++MaxShiftAmt;
+ const IntegerType *ExtTy =
+ IntegerType::get(getContext(), getTypeSizeInBits(Ty) + MaxShiftAmt);
+ // {X,+,N}/C --> {X/C,+,N/C} if safe and N/C can be folded.
+ if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(LHS))
+ if (const SCEVConstant *Step =
+ dyn_cast<SCEVConstant>(AR->getStepRecurrence(*this)))
+ if (!Step->getValue()->getValue()
+ .urem(RHSC->getValue()->getValue()) &&
+ getZeroExtendExpr(AR, ExtTy) ==
+ getAddRecExpr(getZeroExtendExpr(AR->getStart(), ExtTy),
+ getZeroExtendExpr(Step, ExtTy),
+ AR->getLoop())) {
+ 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<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) {
+ const SCEV *Op = M->getOperand(i);
+ const SCEV *Div = getUDivExpr(Op, RHSC);
+ if (!isa<SCEVUDivExpr>(Div) && getMulExpr(Div, RHSC) == Op) {
+ Operands = SmallVector<const SCEV *, 4>(M->op_begin(),
+ M->op_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<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) {
+ const SCEV *Op = getUDivExpr(A->getOperand(i), RHS);
+ if (isa<SCEVUDivExpr>(Op) ||
+ getMulExpr(Op, RHS) != A->getOperand(i))
+ break;
+ Operands.push_back(Op);
+ }
+ if (Operands.size() == A->getNumOperands())
+ return getAddExpr(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<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) {
- const SCEV *Op = getUDivExpr(A->getOperand(i), RHS);
- if (isa<SCEVUDivExpr>(Op) || getMulExpr(Op, RHS) != A->getOperand(i))
- break;
- Operands.push_back(Op);
- }
- if (Operands.size() == A->getNumOperands())
- return getAddExpr(Operands);
}
- }
- // Fold if both operands are constant.
- if (const SCEVConstant *LHSC = dyn_cast<SCEVConstant>(LHS)) {
- Constant *LHSCV = LHSC->getValue();
- Constant *RHSCV = RHSC->getValue();
- return getConstant(cast<ConstantInt>(ConstantExpr::getUDiv(LHSCV,
- RHSCV)));
+ // Fold if both operands are constant.
+ if (const SCEVConstant *LHSC = dyn_cast<SCEVConstant>(LHS)) {
+ Constant *LHSCV = LHSC->getValue();
+ Constant *RHSCV = RHSC->getValue();
+ return getConstant(cast<ConstantInt>(ConstantExpr::getUDiv(LHSCV,
+ RHSCV)));
+ }
}
}
ID.AddPointer(RHS);
void *IP = 0;
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVUDivExpr>();
- new (S) SCEVUDivExpr(ID, LHS, RHS);
+ SCEV *S = new (SCEVAllocator) SCEVUDivExpr(ID.Intern(SCEVAllocator),
+ LHS, RHS);
UniqueSCEVs.InsertNode(S, IP);
return S;
}
Operands.push_back(Start);
if (const SCEVAddRecExpr *StepChrec = dyn_cast<SCEVAddRecExpr>(Step))
if (StepChrec->getLoop() == L) {
- Operands.insert(Operands.end(), StepChrec->op_begin(),
- StepChrec->op_end());
+ Operands.append(StepChrec->op_begin(), StepChrec->op_end());
return getAddRecExpr(Operands, L);
}
return getAddRecExpr(Operands, L, HasNUW, HasNSW); // {X,+,0} --> X
}
+ // It's tempting to want to call getMaxBackedgeTakenCount count here and
+ // use that information to infer NUW and NSW flags. However, computing a
+ // BE count requires calling getAddRecExpr, so we may not yet have a
+ // meaningful BE count at this point (and if we don't, we'd be stuck
+ // with a SCEVCouldNotCompute as the cached BE count).
+
// If HasNSW is true and all the operands are non-negative, infer HasNUW.
if (!HasNUW && HasNSW) {
bool All = true;
SCEVAddRecExpr *S =
static_cast<SCEVAddRecExpr *>(UniqueSCEVs.FindNodeOrInsertPos(ID, IP));
if (!S) {
- S = SCEVAllocator.Allocate<SCEVAddRecExpr>();
- new (S) SCEVAddRecExpr(ID, Operands, L);
+ const SCEV **O = SCEVAllocator.Allocate<const SCEV *>(Operands.size());
+ std::uninitialized_copy(Operands.begin(), Operands.end(), O);
+ S = new (SCEVAllocator) SCEVAddRecExpr(ID.Intern(SCEVAllocator),
+ O, Operands.size(), L);
UniqueSCEVs.InsertNode(S, IP);
}
if (HasNUW) S->setHasNoUnsignedWrap(true);
// maximum-int.
return Ops[0];
}
- }
- if (Ops.size() == 1) return Ops[0];
+ if (Ops.size() == 1) return Ops[0];
+ }
// Find the first SMax
while (Idx < Ops.size() && Ops[Idx]->getSCEVType() < scSMaxExpr)
if (Idx < Ops.size()) {
bool DeletedSMax = false;
while (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(Ops[Idx])) {
- Ops.insert(Ops.end(), SMax->op_begin(), SMax->op_end());
Ops.erase(Ops.begin()+Idx);
+ Ops.append(SMax->op_begin(), SMax->op_end());
DeletedSMax = true;
}
// so, delete one. Since we sorted the list, these values are required to
// be adjacent.
for (unsigned i = 0, e = Ops.size()-1; i != e; ++i)
- if (Ops[i] == Ops[i+1]) { // X smax Y smax Y --> X smax Y
+ // X smax Y smax Y --> X smax Y
+ // X smax Y --> X, if X is always greater than Y
+ if (Ops[i] == Ops[i+1] ||
+ isKnownPredicate(ICmpInst::ICMP_SGE, Ops[i], Ops[i+1])) {
+ Ops.erase(Ops.begin()+i+1, Ops.begin()+i+2);
+ --i; --e;
+ } else if (isKnownPredicate(ICmpInst::ICMP_SLE, Ops[i], Ops[i+1])) {
Ops.erase(Ops.begin()+i, Ops.begin()+i+1);
--i; --e;
}
ID.AddPointer(Ops[i]);
void *IP = 0;
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVSMaxExpr>();
- new (S) SCEVSMaxExpr(ID, Ops);
+ const SCEV **O = SCEVAllocator.Allocate<const SCEV *>(Ops.size());
+ std::uninitialized_copy(Ops.begin(), Ops.end(), O);
+ SCEV *S = new (SCEVAllocator) SCEVSMaxExpr(ID.Intern(SCEVAllocator),
+ O, Ops.size());
UniqueSCEVs.InsertNode(S, IP);
return S;
}
// maximum-int.
return Ops[0];
}
- }
- if (Ops.size() == 1) return Ops[0];
+ if (Ops.size() == 1) return Ops[0];
+ }
// Find the first UMax
while (Idx < Ops.size() && Ops[Idx]->getSCEVType() < scUMaxExpr)
if (Idx < Ops.size()) {
bool DeletedUMax = false;
while (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(Ops[Idx])) {
- Ops.insert(Ops.end(), UMax->op_begin(), UMax->op_end());
Ops.erase(Ops.begin()+Idx);
+ Ops.append(UMax->op_begin(), UMax->op_end());
DeletedUMax = true;
}
// so, delete one. Since we sorted the list, these values are required to
// be adjacent.
for (unsigned i = 0, e = Ops.size()-1; i != e; ++i)
- if (Ops[i] == Ops[i+1]) { // X umax Y umax Y --> X umax Y
+ // X umax Y umax Y --> X umax Y
+ // X umax Y --> X, if X is always greater than Y
+ if (Ops[i] == Ops[i+1] ||
+ isKnownPredicate(ICmpInst::ICMP_UGE, Ops[i], Ops[i+1])) {
+ Ops.erase(Ops.begin()+i+1, Ops.begin()+i+2);
+ --i; --e;
+ } else if (isKnownPredicate(ICmpInst::ICMP_ULE, Ops[i], Ops[i+1])) {
Ops.erase(Ops.begin()+i, Ops.begin()+i+1);
--i; --e;
}
ID.AddPointer(Ops[i]);
void *IP = 0;
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVUMaxExpr>();
- new (S) SCEVUMaxExpr(ID, Ops);
+ const SCEV **O = SCEVAllocator.Allocate<const SCEV *>(Ops.size());
+ std::uninitialized_copy(Ops.begin(), Ops.end(), O);
+ SCEV *S = new (SCEVAllocator) SCEVUMaxExpr(ID.Intern(SCEVAllocator),
+ O, Ops.size());
UniqueSCEVs.InsertNode(S, IP);
return S;
}
return getNotSCEV(getUMaxExpr(getNotSCEV(LHS), getNotSCEV(RHS)));
}
-const SCEV *ScalarEvolution::getFieldOffsetExpr(const StructType *STy,
- unsigned FieldNo) {
- // If we have TargetData we can determine the constant offset.
- if (TD) {
- const Type *IntPtrTy = TD->getIntPtrType(getContext());
- const StructLayout &SL = *TD->getStructLayout(STy);
- uint64_t Offset = SL.getElementOffset(FieldNo);
- return getIntegerSCEV(Offset, IntPtrTy);
- }
-
- // Field 0 is always at offset 0.
- if (FieldNo == 0) {
- const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(STy));
- return getIntegerSCEV(0, Ty);
- }
+const SCEV *ScalarEvolution::getSizeOfExpr(const Type *AllocTy) {
+ // If we have TargetData, we can bypass creating a target-independent
+ // constant expression and then folding it back into a ConstantInt.
+ // This is just a compile-time optimization.
+ if (TD)
+ return getConstant(TD->getIntPtrType(getContext()),
+ TD->getTypeAllocSize(AllocTy));
- // Okay, it looks like we really DO need an offsetof expr. Check to see if we
- // already have one, otherwise create a new one.
- FoldingSetNodeID ID;
- ID.AddInteger(scFieldOffset);
- ID.AddPointer(STy);
- ID.AddInteger(FieldNo);
- void *IP = 0;
- if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVFieldOffsetExpr>();
- const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(STy));
- new (S) SCEVFieldOffsetExpr(ID, Ty, STy, FieldNo);
- UniqueSCEVs.InsertNode(S, IP);
- return S;
+ Constant *C = ConstantExpr::getSizeOf(AllocTy);
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ C = Folded;
+ const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(AllocTy));
+ return getTruncateOrZeroExtend(getSCEV(C), Ty);
}
-const SCEV *ScalarEvolution::getAllocSizeExpr(const Type *AllocTy) {
- // If we have TargetData we can determine the constant size.
- if (TD && AllocTy->isSized()) {
- const Type *IntPtrTy = TD->getIntPtrType(getContext());
- return getIntegerSCEV(TD->getTypeAllocSize(AllocTy), IntPtrTy);
- }
+const SCEV *ScalarEvolution::getAlignOfExpr(const Type *AllocTy) {
+ Constant *C = ConstantExpr::getAlignOf(AllocTy);
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ C = Folded;
+ const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(AllocTy));
+ return getTruncateOrZeroExtend(getSCEV(C), Ty);
+}
- // Expand an array size into the element size times the number
- // of elements.
- if (const ArrayType *ATy = dyn_cast<ArrayType>(AllocTy)) {
- const SCEV *E = getAllocSizeExpr(ATy->getElementType());
- return getMulExpr(
- E, getConstant(ConstantInt::get(cast<IntegerType>(E->getType()),
- ATy->getNumElements())));
- }
+const SCEV *ScalarEvolution::getOffsetOfExpr(const StructType *STy,
+ unsigned FieldNo) {
+ // If we have TargetData, we can bypass creating a target-independent
+ // constant expression and then folding it back into a ConstantInt.
+ // This is just a compile-time optimization.
+ if (TD)
+ return getConstant(TD->getIntPtrType(getContext()),
+ TD->getStructLayout(STy)->getElementOffset(FieldNo));
- // Expand a vector size into the element size times the number
- // of elements.
- if (const VectorType *VTy = dyn_cast<VectorType>(AllocTy)) {
- const SCEV *E = getAllocSizeExpr(VTy->getElementType());
- return getMulExpr(
- E, getConstant(ConstantInt::get(cast<IntegerType>(E->getType()),
- VTy->getNumElements())));
- }
+ Constant *C = ConstantExpr::getOffsetOf(STy, FieldNo);
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ C = Folded;
+ const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(STy));
+ return getTruncateOrZeroExtend(getSCEV(C), Ty);
+}
- // Okay, it looks like we really DO need a sizeof expr. Check to see if we
- // already have one, otherwise create a new one.
- FoldingSetNodeID ID;
- ID.AddInteger(scAllocSize);
- ID.AddPointer(AllocTy);
- void *IP = 0;
- if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVAllocSizeExpr>();
- const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(AllocTy));
- new (S) SCEVAllocSizeExpr(ID, Ty, AllocTy);
- UniqueSCEVs.InsertNode(S, IP);
- return S;
+const SCEV *ScalarEvolution::getOffsetOfExpr(const Type *CTy,
+ Constant *FieldNo) {
+ Constant *C = ConstantExpr::getOffsetOf(CTy, FieldNo);
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
+ if (Constant *Folded = ConstantFoldConstantExpression(CE, TD))
+ C = Folded;
+ const Type *Ty = getEffectiveSCEVType(PointerType::getUnqual(CTy));
+ return getTruncateOrZeroExtend(getSCEV(C), Ty);
}
const SCEV *ScalarEvolution::getUnknown(Value *V) {
ID.AddPointer(V);
void *IP = 0;
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- SCEV *S = SCEVAllocator.Allocate<SCEVUnknown>();
- new (S) SCEVUnknown(ID, V);
+ SCEV *S = new (SCEVAllocator) SCEVUnknown(ID.Intern(SCEVAllocator), V);
UniqueSCEVs.InsertNode(S, IP);
return S;
}
/// has access to target-specific information.
bool ScalarEvolution::isSCEVable(const Type *Ty) const {
// Integers and pointers are always SCEVable.
- return Ty->isInteger() || isa<PointerType>(Ty);
+ return Ty->isIntegerTy() || Ty->isPointerTy();
}
/// getTypeSizeInBits - Return the size in bits of the specified type,
return TD->getTypeSizeInBits(Ty);
// Integer types have fixed sizes.
- if (Ty->isInteger())
+ if (Ty->isIntegerTy())
return Ty->getPrimitiveSizeInBits();
// The only other support type is pointer. Without TargetData, conservatively
// assume pointers are 64-bit.
- assert(isa<PointerType>(Ty) && "isSCEVable permitted a non-SCEVable type!");
+ assert(Ty->isPointerTy() && "isSCEVable permitted a non-SCEVable type!");
return 64;
}
const Type *ScalarEvolution::getEffectiveSCEVType(const Type *Ty) const {
assert(isSCEVable(Ty) && "Type is not SCEVable!");
- if (Ty->isInteger())
+ if (Ty->isIntegerTy())
return Ty;
// The only other support type is pointer.
- assert(isa<PointerType>(Ty) && "Unexpected non-pointer non-integer type!");
+ assert(Ty->isPointerTy() && "Unexpected non-pointer non-integer type!");
if (TD) return TD->getIntPtrType(getContext());
// Without TargetData, conservatively assume pointers are 64-bit.
return S;
}
-/// getIntegerSCEV - Given a SCEVable type, create a constant for the
-/// specified signed integer value and return a SCEV for the constant.
-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
///
const SCEV *ScalarEvolution::getNegativeSCEV(const SCEV *V) {
///
const SCEV *ScalarEvolution::getMinusSCEV(const SCEV *LHS,
const SCEV *RHS) {
+ // Fast path: X - X --> 0.
+ if (LHS == RHS)
+ return getConstant(LHS->getType(), 0);
+
// X - Y --> X + -Y
return getAddExpr(LHS, getNegativeSCEV(RHS));
}
ScalarEvolution::getTruncateOrZeroExtend(const SCEV *V,
const Type *Ty) {
const Type *SrcTy = V->getType();
- assert((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((SrcTy->isIntegerTy() || SrcTy->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot truncate or zero extend with non-integer arguments!");
if (getTypeSizeInBits(SrcTy) == getTypeSizeInBits(Ty))
return V; // No conversion
ScalarEvolution::getTruncateOrSignExtend(const SCEV *V,
const Type *Ty) {
const Type *SrcTy = V->getType();
- assert((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((SrcTy->isIntegerTy() || SrcTy->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot truncate or zero extend with non-integer arguments!");
if (getTypeSizeInBits(SrcTy) == getTypeSizeInBits(Ty))
return V; // No conversion
const SCEV *
ScalarEvolution::getNoopOrZeroExtend(const SCEV *V, const Type *Ty) {
const Type *SrcTy = V->getType();
- assert((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((SrcTy->isIntegerTy() || SrcTy->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot noop or zero extend with non-integer arguments!");
assert(getTypeSizeInBits(SrcTy) <= getTypeSizeInBits(Ty) &&
"getNoopOrZeroExtend cannot truncate!");
const SCEV *
ScalarEvolution::getNoopOrSignExtend(const SCEV *V, const Type *Ty) {
const Type *SrcTy = V->getType();
- assert((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((SrcTy->isIntegerTy() || SrcTy->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot noop or sign extend with non-integer arguments!");
assert(getTypeSizeInBits(SrcTy) <= getTypeSizeInBits(Ty) &&
"getNoopOrSignExtend cannot truncate!");
const SCEV *
ScalarEvolution::getNoopOrAnyExtend(const SCEV *V, const Type *Ty) {
const Type *SrcTy = V->getType();
- assert((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((SrcTy->isIntegerTy() || SrcTy->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot noop or any extend with non-integer arguments!");
assert(getTypeSizeInBits(SrcTy) <= getTypeSizeInBits(Ty) &&
"getNoopOrAnyExtend cannot truncate!");
const SCEV *
ScalarEvolution::getTruncateOrNoop(const SCEV *V, const Type *Ty) {
const Type *SrcTy = V->getType();
- assert((SrcTy->isInteger() || isa<PointerType>(SrcTy)) &&
- (Ty->isInteger() || isa<PointerType>(Ty)) &&
+ assert((SrcTy->isIntegerTy() || SrcTy->isPointerTy()) &&
+ (Ty->isIntegerTy() || Ty->isPointerTy()) &&
"Cannot truncate or noop with non-integer arguments!");
assert(getTypeSizeInBits(SrcTy) >= getTypeSizeInBits(Ty) &&
"getTruncateOrNoop cannot extend!");
/// the Scalars map if they reference SymName. This is used during PHI
/// resolution.
void
-ScalarEvolution::ForgetSymbolicName(Instruction *I, const SCEV *SymName) {
+ScalarEvolution::ForgetSymbolicName(Instruction *PN, const SCEV *SymName) {
SmallVector<Instruction *, 16> Worklist;
- PushDefUseChildren(I, Worklist);
+ PushDefUseChildren(PN, Worklist);
SmallPtrSet<Instruction *, 8> Visited;
- Visited.insert(I);
+ Visited.insert(PN);
while (!Worklist.empty()) {
Instruction *I = Worklist.pop_back_val();
if (!Visited.insert(I)) continue;
if (It != Scalars.end()) {
// Short-circuit the def-use traversal if the symbolic name
// ceases to appear in expressions.
- if (!It->second->hasOperand(SymName))
+ if (It->second != SymName && !It->second->hasOperand(SymName))
continue;
// SCEVUnknown for a PHI either means that it has an unrecognized
- // structure, or it's a PHI that's in the progress of being computed
- // by createNodeForPHI. In the former case, additional loop trip
- // count information isn't going to change anything. In the later
- // case, createNodeForPHI will perform the necessary updates on its
- // own when it gets to that point.
- if (!isa<PHINode>(I) || !isa<SCEVUnknown>(It->second)) {
+ // structure, it's a PHI that's in the progress of being computed
+ // by createNodeForPHI, or it's a single-value PHI. In the first case,
+ // additional loop trip count information isn't going to change anything.
+ // In the second case, createNodeForPHI will perform the necessary
+ // updates on its own when it gets to that point. In the third, we do
+ // want to forget the SCEVUnknown.
+ if (!isa<PHINode>(I) ||
+ !isa<SCEVUnknown>(It->second) ||
+ (I != PN && It->second == SymName)) {
ValuesAtScopes.erase(It->second);
Scalars.erase(It);
}
/// a loop header, making it a potential recurrence, or it doesn't.
///
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()) {
- // If it lives in the loop header, it has two incoming values, one
- // from outside the loop, and one from inside.
- unsigned IncomingEdge = L->contains(PN->getIncomingBlock(0));
- unsigned BackEdge = IncomingEdge^1;
-
+ if (const Loop *L = LI->getLoopFor(PN->getParent()))
+ if (L->getHeader() == PN->getParent()) {
+ // The loop may have multiple entrances or multiple exits; we can analyze
+ // this phi as an addrec if it has a unique entry value and a unique
+ // backedge value.
+ Value *BEValueV = 0, *StartValueV = 0;
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
+ Value *V = PN->getIncomingValue(i);
+ if (L->contains(PN->getIncomingBlock(i))) {
+ if (!BEValueV) {
+ BEValueV = V;
+ } else if (BEValueV != V) {
+ BEValueV = 0;
+ break;
+ }
+ } else if (!StartValueV) {
+ StartValueV = V;
+ } else if (StartValueV != V) {
+ StartValueV = 0;
+ break;
+ }
+ }
+ if (BEValueV && StartValueV) {
// While we are analyzing this PHI node, handle its value symbolically.
const SCEV *SymbolicName = getUnknown(PN);
assert(Scalars.find(PN) == Scalars.end() &&
// Using this symbolic name for the PHI, analyze the value coming around
// the back-edge.
- Value *BEValueV = PN->getIncomingValue(BackEdge);
const SCEV *BEValue = getSCEV(BEValueV);
// NOTE: If BEValue is loop invariant, we know that the PHI node just
HasNSW = true;
}
- const SCEV *StartVal =
- getSCEV(PN->getIncomingValue(IncomingEdge));
+ const SCEV *StartVal = getSCEV(StartValueV);
const SCEV *PHISCEV =
getAddRecExpr(StartVal, Accum, L, HasNUW, HasNSW);
// 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()) {
- const SCEV *StartVal = getSCEV(PN->getIncomingValue(IncomingEdge));
+ const SCEV *StartVal = getSCEV(StartValueV);
// 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))) {
+ AddRec->getOperand(1))) {
const SCEV *PHISCEV =
getAddRecExpr(StartVal, AddRec->getOperand(1), L);
}
}
}
-
- return SymbolicName;
}
+ }
- // It's tempting to recognize PHIs with a unique incoming value, however
- // this leads passes like indvars to break LCSSA form. Fortunately, such
- // PHIs are rare, as instcombine zaps them.
+ // If the PHI has a single incoming value, follow that value, unless the
+ // PHI's incoming blocks are in a different loop, in which case doing so
+ // risks breaking LCSSA form. Instcombine would normally zap these, but
+ // it doesn't have DominatorTree information, so it may miss cases.
+ if (Value *V = PN->hasConstantValue(DT)) {
+ bool AllSameLoop = true;
+ Loop *PNLoop = LI->getLoopFor(PN->getParent());
+ for (size_t i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+ if (LI->getLoopFor(PN->getIncomingBlock(i)) != PNLoop) {
+ AllSameLoop = false;
+ break;
+ }
+ if (AllSameLoop)
+ return getSCEV(V);
+ }
// If it's not a loop phi, we can't handle it yet.
return getUnknown(PN);
///
const SCEV *ScalarEvolution::createNodeForGEP(GEPOperator *GEP) {
- bool InBounds = GEP->isInBounds();
+ // Don't blindly transfer the inbounds flag from the GEP instruction to the
+ // Add expression, because the Instruction may be guarded by control flow
+ // and the no-overflow bits may not be valid for the expression in any
+ // context.
+
const Type *IntPtrTy = getEffectiveSCEVType(GEP->getType());
Value *Base = GEP->getOperand(0);
// Don't attempt to analyze GEPs over unsized objects.
if (!cast<PointerType>(Base->getType())->getElementType()->isSized())
return getUnknown(GEP);
- const SCEV *TotalOffset = getIntegerSCEV(0, IntPtrTy);
+ const SCEV *TotalOffset = getConstant(IntPtrTy, 0);
gep_type_iterator GTI = gep_type_begin(GEP);
for (GetElementPtrInst::op_iterator I = next(GEP->op_begin()),
E = GEP->op_end();
if (const StructType *STy = dyn_cast<StructType>(*GTI++)) {
// For a struct, add the member offset.
unsigned FieldNo = cast<ConstantInt>(Index)->getZExtValue();
- TotalOffset = getAddExpr(TotalOffset,
- getFieldOffsetExpr(STy, FieldNo),
- /*HasNUW=*/false, /*HasNSW=*/InBounds);
+ const SCEV *FieldOffset = getOffsetOfExpr(STy, FieldNo);
+
+ // Add the field offset to the running total offset.
+ TotalOffset = getAddExpr(TotalOffset, FieldOffset);
} else {
// For an array, add the element offset, explicitly scaled.
- const SCEV *LocalOffset = getSCEV(Index);
- if (!isa<PointerType>(LocalOffset->getType()))
- // Getelementptr indicies are signed.
- LocalOffset = getTruncateOrSignExtend(LocalOffset, IntPtrTy);
- // Lower "inbounds" GEPs to NSW arithmetic.
- LocalOffset = getMulExpr(LocalOffset, getAllocSizeExpr(*GTI),
- /*HasNUW=*/false, /*HasNSW=*/InBounds);
- TotalOffset = getAddExpr(TotalOffset, LocalOffset,
- /*HasNUW=*/false, /*HasNSW=*/InBounds);
+ const SCEV *ElementSize = getSizeOfExpr(*GTI);
+ const SCEV *IndexS = getSCEV(Index);
+ // Getelementptr indices are signed.
+ IndexS = getTruncateOrSignExtend(IndexS, IntPtrTy);
+
+ // Multiply the index by the element size to compute the element offset.
+ const SCEV *LocalOffset = getMulExpr(IndexS, ElementSize);
+
+ // Add the element offset to the running total offset.
+ TotalOffset = getAddExpr(TotalOffset, LocalOffset);
}
}
- return getAddExpr(getSCEV(Base), TotalOffset,
- /*HasNUW=*/false, /*HasNSW=*/InBounds);
+
+ // Get the SCEV for the GEP base.
+ const SCEV *BaseS = getSCEV(Base);
+
+ // Add the total offset from all the GEP indices to the base.
+ return getAddExpr(BaseS, TotalOffset);
}
/// GetMinTrailingZeros - Determine the minimum number of zero bits that S is
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
return ConstantRange(C->getValue()->getValue());
+ unsigned BitWidth = getTypeSizeInBits(S->getType());
+ ConstantRange ConservativeResult(BitWidth, /*isFullSet=*/true);
+
+ // If the value has known zeros, the maximum unsigned value will have those
+ // known zeros as well.
+ uint32_t TZ = GetMinTrailingZeros(S);
+ if (TZ != 0)
+ ConservativeResult =
+ ConstantRange(APInt::getMinValue(BitWidth),
+ APInt::getMaxValue(BitWidth).lshr(TZ).shl(TZ) + 1);
+
if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
ConstantRange X = getUnsignedRange(Add->getOperand(0));
for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
X = X.add(getUnsignedRange(Add->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(S)) {
ConstantRange X = getUnsignedRange(Mul->getOperand(0));
for (unsigned i = 1, e = Mul->getNumOperands(); i != e; ++i)
X = X.multiply(getUnsignedRange(Mul->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(S)) {
ConstantRange X = getUnsignedRange(SMax->getOperand(0));
for (unsigned i = 1, e = SMax->getNumOperands(); i != e; ++i)
X = X.smax(getUnsignedRange(SMax->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(S)) {
ConstantRange X = getUnsignedRange(UMax->getOperand(0));
for (unsigned i = 1, e = UMax->getNumOperands(); i != e; ++i)
X = X.umax(getUnsignedRange(UMax->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
ConstantRange X = getUnsignedRange(UDiv->getLHS());
ConstantRange Y = getUnsignedRange(UDiv->getRHS());
- return X.udiv(Y);
+ return ConservativeResult.intersectWith(X.udiv(Y));
}
if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
ConstantRange X = getUnsignedRange(ZExt->getOperand());
- return X.zeroExtend(cast<IntegerType>(ZExt->getType())->getBitWidth());
+ return ConservativeResult.intersectWith(X.zeroExtend(BitWidth));
}
if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
ConstantRange X = getUnsignedRange(SExt->getOperand());
- return X.signExtend(cast<IntegerType>(SExt->getType())->getBitWidth());
+ return ConservativeResult.intersectWith(X.signExtend(BitWidth));
}
if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
ConstantRange X = getUnsignedRange(Trunc->getOperand());
- return X.truncate(cast<IntegerType>(Trunc->getType())->getBitWidth());
+ return ConservativeResult.intersectWith(X.truncate(BitWidth));
}
- ConstantRange FullSet(getTypeSizeInBits(S->getType()), true);
-
if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
- const SCEV *T = getBackedgeTakenCount(AddRec->getLoop());
- const SCEVConstant *Trip = dyn_cast<SCEVConstant>(T);
- ConstantRange ConservativeResult = FullSet;
-
// If there's no unsigned wrap, the value will never be less than its
// initial value.
if (AddRec->hasNoUnsignedWrap())
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(AddRec->getStart()))
- ConservativeResult =
- ConstantRange(C->getValue()->getValue(),
- APInt(getTypeSizeInBits(C->getType()), 0));
+ if (!C->getValue()->isZero())
+ ConservativeResult =
+ ConservativeResult.intersectWith(
+ ConstantRange(C->getValue()->getValue(), APInt(BitWidth, 0)));
// TODO: non-affine addrec
- if (Trip && AddRec->isAffine()) {
+ if (AddRec->isAffine()) {
const Type *Ty = AddRec->getType();
const SCEV *MaxBECount = getMaxBackedgeTakenCount(AddRec->getLoop());
- if (getTypeSizeInBits(MaxBECount->getType()) <= getTypeSizeInBits(Ty)) {
+ if (!isa<SCEVCouldNotCompute>(MaxBECount) &&
+ getTypeSizeInBits(MaxBECount->getType()) <= BitWidth) {
MaxBECount = getNoopOrZeroExtend(MaxBECount, Ty);
const SCEV *Start = AddRec->getStart();
- const SCEV *End = AddRec->evaluateAtIteration(MaxBECount, *this);
+ const SCEV *Step = AddRec->getStepRecurrence(*this);
- // Check for overflow.
- if (!AddRec->hasNoUnsignedWrap())
+ ConstantRange StartRange = getUnsignedRange(Start);
+ ConstantRange StepRange = getSignedRange(Step);
+ ConstantRange MaxBECountRange = getUnsignedRange(MaxBECount);
+ ConstantRange EndRange =
+ StartRange.add(MaxBECountRange.multiply(StepRange));
+
+ // Check for overflow. This must be done with ConstantRange arithmetic
+ // because we could be called from within the ScalarEvolution overflow
+ // checking code.
+ ConstantRange ExtStartRange = StartRange.zextOrTrunc(BitWidth*2+1);
+ ConstantRange ExtStepRange = StepRange.sextOrTrunc(BitWidth*2+1);
+ ConstantRange ExtMaxBECountRange =
+ MaxBECountRange.zextOrTrunc(BitWidth*2+1);
+ ConstantRange ExtEndRange = EndRange.zextOrTrunc(BitWidth*2+1);
+ if (ExtStartRange.add(ExtMaxBECountRange.multiply(ExtStepRange)) !=
+ ExtEndRange)
return ConservativeResult;
- ConstantRange StartRange = getUnsignedRange(Start);
- ConstantRange EndRange = getUnsignedRange(End);
APInt Min = APIntOps::umin(StartRange.getUnsignedMin(),
EndRange.getUnsignedMin());
APInt Max = APIntOps::umax(StartRange.getUnsignedMax(),
EndRange.getUnsignedMax());
if (Min.isMinValue() && Max.isMaxValue())
return ConservativeResult;
- return ConstantRange(Min, Max+1);
+ return ConservativeResult.intersectWith(ConstantRange(Min, Max+1));
}
}
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
// For a SCEVUnknown, ask ValueTracking.
- unsigned BitWidth = getTypeSizeInBits(U->getType());
APInt Mask = APInt::getAllOnesValue(BitWidth);
APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
ComputeMaskedBits(U->getValue(), Mask, Zeros, Ones, TD);
if (Ones == ~Zeros + 1)
- return FullSet;
- return ConstantRange(Ones, ~Zeros + 1);
+ return ConservativeResult;
+ return ConservativeResult.intersectWith(ConstantRange(Ones, ~Zeros + 1));
}
- return FullSet;
+ return ConservativeResult;
}
/// getSignedRange - Determine the signed range for a particular SCEV.
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
return ConstantRange(C->getValue()->getValue());
+ unsigned BitWidth = getTypeSizeInBits(S->getType());
+ ConstantRange ConservativeResult(BitWidth, /*isFullSet=*/true);
+
+ // If the value has known zeros, the maximum signed value will have those
+ // known zeros as well.
+ uint32_t TZ = GetMinTrailingZeros(S);
+ if (TZ != 0)
+ ConservativeResult =
+ ConstantRange(APInt::getSignedMinValue(BitWidth),
+ APInt::getSignedMaxValue(BitWidth).ashr(TZ).shl(TZ) + 1);
+
if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
ConstantRange X = getSignedRange(Add->getOperand(0));
for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
X = X.add(getSignedRange(Add->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(S)) {
ConstantRange X = getSignedRange(Mul->getOperand(0));
for (unsigned i = 1, e = Mul->getNumOperands(); i != e; ++i)
X = X.multiply(getSignedRange(Mul->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(S)) {
ConstantRange X = getSignedRange(SMax->getOperand(0));
for (unsigned i = 1, e = SMax->getNumOperands(); i != e; ++i)
X = X.smax(getSignedRange(SMax->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVUMaxExpr *UMax = dyn_cast<SCEVUMaxExpr>(S)) {
ConstantRange X = getSignedRange(UMax->getOperand(0));
for (unsigned i = 1, e = UMax->getNumOperands(); i != e; ++i)
X = X.umax(getSignedRange(UMax->getOperand(i)));
- return X;
+ return ConservativeResult.intersectWith(X);
}
if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
ConstantRange X = getSignedRange(UDiv->getLHS());
ConstantRange Y = getSignedRange(UDiv->getRHS());
- return X.udiv(Y);
+ return ConservativeResult.intersectWith(X.udiv(Y));
}
if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
ConstantRange X = getSignedRange(ZExt->getOperand());
- return X.zeroExtend(cast<IntegerType>(ZExt->getType())->getBitWidth());
+ return ConservativeResult.intersectWith(X.zeroExtend(BitWidth));
}
if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
ConstantRange X = getSignedRange(SExt->getOperand());
- return X.signExtend(cast<IntegerType>(SExt->getType())->getBitWidth());
+ return ConservativeResult.intersectWith(X.signExtend(BitWidth));
}
if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
ConstantRange X = getSignedRange(Trunc->getOperand());
- return X.truncate(cast<IntegerType>(Trunc->getType())->getBitWidth());
+ return ConservativeResult.intersectWith(X.truncate(BitWidth));
}
- ConstantRange FullSet(getTypeSizeInBits(S->getType()), true);
-
if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
- const SCEV *T = getBackedgeTakenCount(AddRec->getLoop());
- const SCEVConstant *Trip = dyn_cast<SCEVConstant>(T);
- ConstantRange ConservativeResult = FullSet;
-
// If there's no signed wrap, and all the operands have the same sign or
// zero, the value won't ever change sign.
if (AddRec->hasNoSignedWrap()) {
if (!isKnownNonNegative(AddRec->getOperand(i))) AllNonNeg = false;
if (!isKnownNonPositive(AddRec->getOperand(i))) AllNonPos = false;
}
- unsigned BitWidth = getTypeSizeInBits(AddRec->getType());
if (AllNonNeg)
- ConservativeResult = ConstantRange(APInt(BitWidth, 0),
- APInt::getSignedMinValue(BitWidth));
+ ConservativeResult = ConservativeResult.intersectWith(
+ ConstantRange(APInt(BitWidth, 0),
+ APInt::getSignedMinValue(BitWidth)));
else if (AllNonPos)
- ConservativeResult = ConstantRange(APInt::getSignedMinValue(BitWidth),
- APInt(BitWidth, 1));
+ ConservativeResult = ConservativeResult.intersectWith(
+ ConstantRange(APInt::getSignedMinValue(BitWidth),
+ APInt(BitWidth, 1)));
}
// TODO: non-affine addrec
- if (Trip && AddRec->isAffine()) {
+ if (AddRec->isAffine()) {
const Type *Ty = AddRec->getType();
const SCEV *MaxBECount = getMaxBackedgeTakenCount(AddRec->getLoop());
- if (getTypeSizeInBits(MaxBECount->getType()) <= getTypeSizeInBits(Ty)) {
+ if (!isa<SCEVCouldNotCompute>(MaxBECount) &&
+ getTypeSizeInBits(MaxBECount->getType()) <= BitWidth) {
MaxBECount = getNoopOrZeroExtend(MaxBECount, Ty);
const SCEV *Start = AddRec->getStart();
- const SCEV *End = AddRec->evaluateAtIteration(MaxBECount, *this);
+ const SCEV *Step = AddRec->getStepRecurrence(*this);
- // Check for overflow.
- if (!AddRec->hasNoSignedWrap())
+ ConstantRange StartRange = getSignedRange(Start);
+ ConstantRange StepRange = getSignedRange(Step);
+ ConstantRange MaxBECountRange = getUnsignedRange(MaxBECount);
+ ConstantRange EndRange =
+ StartRange.add(MaxBECountRange.multiply(StepRange));
+
+ // Check for overflow. This must be done with ConstantRange arithmetic
+ // because we could be called from within the ScalarEvolution overflow
+ // checking code.
+ ConstantRange ExtStartRange = StartRange.sextOrTrunc(BitWidth*2+1);
+ ConstantRange ExtStepRange = StepRange.sextOrTrunc(BitWidth*2+1);
+ ConstantRange ExtMaxBECountRange =
+ MaxBECountRange.zextOrTrunc(BitWidth*2+1);
+ ConstantRange ExtEndRange = EndRange.sextOrTrunc(BitWidth*2+1);
+ if (ExtStartRange.add(ExtMaxBECountRange.multiply(ExtStepRange)) !=
+ ExtEndRange)
return ConservativeResult;
- ConstantRange StartRange = getSignedRange(Start);
- ConstantRange EndRange = getSignedRange(End);
APInt Min = APIntOps::smin(StartRange.getSignedMin(),
EndRange.getSignedMin());
APInt Max = APIntOps::smax(StartRange.getSignedMax(),
EndRange.getSignedMax());
if (Min.isMinSignedValue() && Max.isMaxSignedValue())
return ConservativeResult;
- return ConstantRange(Min, Max+1);
+ return ConservativeResult.intersectWith(ConstantRange(Min, Max+1));
}
}
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
// For a SCEVUnknown, ask ValueTracking.
- unsigned BitWidth = getTypeSizeInBits(U->getType());
- if (!U->getValue()->getType()->isInteger() && !TD)
- return FullSet;
+ if (!U->getValue()->getType()->isIntegerTy() && !TD)
+ return ConservativeResult;
unsigned NS = ComputeNumSignBits(U->getValue(), TD);
if (NS == 1)
- return FullSet;
- return
+ return ConservativeResult;
+ return ConservativeResult.intersectWith(
ConstantRange(APInt::getSignedMinValue(BitWidth).ashr(NS - 1),
- APInt::getSignedMaxValue(BitWidth).ashr(NS - 1)+1);
+ APInt::getSignedMaxValue(BitWidth).ashr(NS - 1)+1));
}
- return FullSet;
+ return ConservativeResult;
}
/// createSCEV - We know that there is no SCEV for the specified value.
return getUnknown(V);
unsigned Opcode = Instruction::UserOp1;
- if (Instruction *I = dyn_cast<Instruction>(V))
+ if (Instruction *I = dyn_cast<Instruction>(V)) {
Opcode = I->getOpcode();
- else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
+
+ // Don't attempt to analyze instructions in blocks that aren't
+ // reachable. Such instructions don't matter, and they aren't required
+ // to obey basic rules for definitions dominating uses which this
+ // analysis depends on.
+ if (!DT->isReachableFromEntry(I->getParent()))
+ return getUnknown(V);
+ } 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());
+ return getConstant(V->getType(), 0);
else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
return GA->mayBeOverridden() ? getUnknown(V) : getSCEV(GA->getAliasee());
else
Operator *U = cast<Operator>(V);
switch (Opcode) {
case Instruction::Add:
- // Don't transfer the NSW and NUW bits from the Add instruction to the
- // Add expression, because the Instruction may be guarded by control
- // flow and the no-overflow bits may not be valid for the expression in
- // any context.
return getAddExpr(getSCEV(U->getOperand(0)),
getSCEV(U->getOperand(1)));
case Instruction::Mul:
- // Don't transfer the NSW and NUW bits from the Mul instruction to the
- // Mul expression, as with Add.
return getMulExpr(getSCEV(U->getOperand(0)),
getSCEV(U->getOperand(1)));
case Instruction::UDiv:
const Type *Z0Ty = Z0->getType();
unsigned Z0TySize = getTypeSizeInBits(Z0Ty);
- // If C is a low-bits mask, the zero extend is zerving to
+ // If C is a low-bits mask, the zero extend is serving to
// mask off the high bits. Complement the operand and
// re-apply the zext.
if (APIntOps::isMask(Z0TySize, CI->getValue()))
case Instruction::Shl:
// Turn shift left of a constant amount into a multiply.
if (ConstantInt *SA = dyn_cast<ConstantInt>(U->getOperand(1))) {
- uint32_t BitWidth = cast<IntegerType>(V->getType())->getBitWidth();
+ uint32_t BitWidth = cast<IntegerType>(U->getType())->getBitWidth();
+
+ // If the shift count is not less than the bitwidth, the result of
+ // the shift is undefined. Don't try to analyze it, because the
+ // resolution chosen here may differ from the resolution chosen in
+ // other parts of the compiler.
+ if (SA->getValue().uge(BitWidth))
+ break;
+
Constant *X = ConstantInt::get(getContext(),
- APInt(BitWidth, 1).shl(SA->getLimitedValue(BitWidth)));
+ APInt(BitWidth, 1).shl(SA->getZExtValue()));
return getMulExpr(getSCEV(U->getOperand(0)), getSCEV(X));
}
break;
case Instruction::LShr:
// Turn logical shift right of a constant into a unsigned divide.
if (ConstantInt *SA = dyn_cast<ConstantInt>(U->getOperand(1))) {
- uint32_t BitWidth = cast<IntegerType>(V->getType())->getBitWidth();
+ uint32_t BitWidth = cast<IntegerType>(U->getType())->getBitWidth();
+
+ // If the shift count is not less than the bitwidth, the result of
+ // the shift is undefined. Don't try to analyze it, because the
+ // resolution chosen here may differ from the resolution chosen in
+ // other parts of the compiler.
+ if (SA->getValue().uge(BitWidth))
+ break;
+
Constant *X = ConstantInt::get(getContext(),
- APInt(BitWidth, 1).shl(SA->getLimitedValue(BitWidth)));
+ APInt(BitWidth, 1).shl(SA->getZExtValue()));
return getUDivExpr(getSCEV(U->getOperand(0)), getSCEV(X));
}
break;
case Instruction::AShr:
// For a two-shift sext-inreg, use sext(trunc(x)) as the SCEV expression.
if (ConstantInt *CI = dyn_cast<ConstantInt>(U->getOperand(1)))
- if (Instruction *L = dyn_cast<Instruction>(U->getOperand(0)))
+ if (Operator *L = dyn_cast<Operator>(U->getOperand(0)))
if (L->getOpcode() == Instruction::Shl &&
L->getOperand(1) == U->getOperand(1)) {
- unsigned BitWidth = getTypeSizeInBits(U->getType());
+ uint64_t BitWidth = getTypeSizeInBits(U->getType());
+
+ // If the shift count is not less than the bitwidth, the result of
+ // the shift is undefined. Don't try to analyze it, because the
+ // resolution chosen here may differ from the resolution chosen in
+ // other parts of the compiler.
+ if (CI->getValue().uge(BitWidth))
+ break;
+
uint64_t Amt = BitWidth - CI->getZExtValue();
if (Amt == BitWidth)
return getSCEV(L->getOperand(0)); // shift by zero --> noop
- if (Amt > BitWidth)
- return getIntegerSCEV(0, U->getType()); // value is undefined
return
getSignExtendExpr(getTruncateExpr(getSCEV(L->getOperand(0)),
- IntegerType::get(getContext(), Amt)),
- U->getType());
+ IntegerType::get(getContext(),
+ Amt)),
+ U->getType());
}
break;
return getSCEV(U->getOperand(0));
break;
- // It's tempting to handle inttoptr and ptrtoint, however this can
- // lead to pointer expressions which cannot be expanded to GEPs
- // (because they may overflow). For now, the only pointer-typed
- // expressions we handle are GEPs and address literals.
+ // It's tempting to handle inttoptr and ptrtoint as no-ops, however this can
+ // lead to pointer expressions which cannot safely be expanded to GEPs,
+ // because ScalarEvolution doesn't respect the GEP aliasing rules when
+ // simplifying integer expressions.
case Instruction::GetElementPtr:
return createNodeForGEP(cast<GEPOperator>(U));
// fall through
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE:
- if (LHS == U->getOperand(1) && RHS == U->getOperand(2))
- return getSMaxExpr(getSCEV(LHS), getSCEV(RHS));
- else if (LHS == U->getOperand(2) && RHS == U->getOperand(1))
- return getSMinExpr(getSCEV(LHS), getSCEV(RHS));
+ // a >s b ? a+x : b+x -> smax(a, b)+x
+ // a >s b ? b+x : a+x -> smin(a, b)+x
+ if (LHS->getType() == U->getType()) {
+ const SCEV *LS = getSCEV(LHS);
+ const SCEV *RS = getSCEV(RHS);
+ const SCEV *LA = getSCEV(U->getOperand(1));
+ const SCEV *RA = getSCEV(U->getOperand(2));
+ const SCEV *LDiff = getMinusSCEV(LA, LS);
+ const SCEV *RDiff = getMinusSCEV(RA, RS);
+ if (LDiff == RDiff)
+ return getAddExpr(getSMaxExpr(LS, RS), LDiff);
+ LDiff = getMinusSCEV(LA, RS);
+ RDiff = getMinusSCEV(RA, LS);
+ if (LDiff == RDiff)
+ return getAddExpr(getSMinExpr(LS, RS), LDiff);
+ }
break;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
// fall through
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
- if (LHS == U->getOperand(1) && RHS == U->getOperand(2))
- return getUMaxExpr(getSCEV(LHS), getSCEV(RHS));
- else if (LHS == U->getOperand(2) && RHS == U->getOperand(1))
- return getUMinExpr(getSCEV(LHS), getSCEV(RHS));
+ // a >u b ? a+x : b+x -> umax(a, b)+x
+ // a >u b ? b+x : a+x -> umin(a, b)+x
+ if (LHS->getType() == U->getType()) {
+ const SCEV *LS = getSCEV(LHS);
+ const SCEV *RS = getSCEV(RHS);
+ const SCEV *LA = getSCEV(U->getOperand(1));
+ const SCEV *RA = getSCEV(U->getOperand(2));
+ const SCEV *LDiff = getMinusSCEV(LA, LS);
+ const SCEV *RDiff = getMinusSCEV(RA, RS);
+ if (LDiff == RDiff)
+ return getAddExpr(getUMaxExpr(LS, RS), LDiff);
+ LDiff = getMinusSCEV(LA, RS);
+ RDiff = getMinusSCEV(RA, LS);
+ if (LDiff == RDiff)
+ return getAddExpr(getUMinExpr(LS, RS), LDiff);
+ }
break;
case ICmpInst::ICMP_NE:
- // n != 0 ? n : 1 -> umax(n, 1)
- if (LHS == U->getOperand(1) &&
- isa<ConstantInt>(U->getOperand(2)) &&
- cast<ConstantInt>(U->getOperand(2))->isOne() &&
+ // n != 0 ? n+x : 1+x -> umax(n, 1)+x
+ if (LHS->getType() == U->getType() &&
isa<ConstantInt>(RHS) &&
- cast<ConstantInt>(RHS)->isZero())
- return getUMaxExpr(getSCEV(LHS), getSCEV(U->getOperand(2)));
+ cast<ConstantInt>(RHS)->isZero()) {
+ const SCEV *One = getConstant(LHS->getType(), 1);
+ const SCEV *LS = getSCEV(LHS);
+ const SCEV *LA = getSCEV(U->getOperand(1));
+ const SCEV *RA = getSCEV(U->getOperand(2));
+ const SCEV *LDiff = getMinusSCEV(LA, LS);
+ const SCEV *RDiff = getMinusSCEV(RA, One);
+ if (LDiff == RDiff)
+ return getAddExpr(getUMaxExpr(LS, One), LDiff);
+ }
break;
case ICmpInst::ICMP_EQ:
- // n == 0 ? 1 : n -> umax(n, 1)
- if (LHS == U->getOperand(2) &&
- isa<ConstantInt>(U->getOperand(1)) &&
- cast<ConstantInt>(U->getOperand(1))->isOne() &&
+ // n == 0 ? 1+x : n+x -> umax(n, 1)+x
+ if (LHS->getType() == U->getType() &&
isa<ConstantInt>(RHS) &&
- cast<ConstantInt>(RHS)->isZero())
- return getUMaxExpr(getSCEV(LHS), getSCEV(U->getOperand(1)));
+ cast<ConstantInt>(RHS)->isZero()) {
+ const SCEV *One = getConstant(LHS->getType(), 1);
+ const SCEV *LS = getSCEV(LHS);
+ const SCEV *LA = getSCEV(U->getOperand(1));
+ const SCEV *RA = getSCEV(U->getOperand(2));
+ const SCEV *LDiff = getMinusSCEV(LA, One);
+ const SCEV *RDiff = getMinusSCEV(RA, LS);
+ if (LDiff == RDiff)
+ return getAddExpr(getUMaxExpr(LS, One), LDiff);
+ }
break;
default:
break;
const ScalarEvolution::BackedgeTakenInfo &
ScalarEvolution::getBackedgeTakenInfo(const Loop *L) {
// Initially insert a CouldNotCompute for this loop. If the insertion
- // succeeds, procede to actually compute a backedge-taken count and
+ // succeeds, proceed to actually compute a backedge-taken count and
// update the value. The temporary CouldNotCompute value tells SCEV
// code elsewhere that it shouldn't attempt to request a new
// backedge-taken count, which could result in infinite recursion.
std::pair<std::map<const Loop *, BackedgeTakenInfo>::iterator, bool> Pair =
BackedgeTakenCounts.insert(std::make_pair(L, getCouldNotCompute()));
if (Pair.second) {
- BackedgeTakenInfo ItCount = ComputeBackedgeTakenCount(L);
- if (ItCount.Exact != getCouldNotCompute()) {
- assert(ItCount.Exact->isLoopInvariant(L) &&
- ItCount.Max->isLoopInvariant(L) &&
- "Computed trip count isn't loop invariant for loop!");
+ BackedgeTakenInfo BECount = ComputeBackedgeTakenCount(L);
+ if (BECount.Exact != getCouldNotCompute()) {
+ assert(BECount.Exact->isLoopInvariant(L) &&
+ BECount.Max->isLoopInvariant(L) &&
+ "Computed backedge-taken count isn't loop invariant for loop!");
++NumTripCountsComputed;
// Update the value in the map.
- Pair.first->second = ItCount;
+ Pair.first->second = BECount;
} else {
- if (ItCount.Max != getCouldNotCompute())
+ if (BECount.Max != getCouldNotCompute())
// Update the value in the map.
- Pair.first->second = ItCount;
+ Pair.first->second = BECount;
if (isa<PHINode>(L->getHeader()->begin()))
// Only count loops that have phi nodes as not being computable.
++NumTripCountsNotComputed;
// conservative estimates made without the benefit of trip count
// information. This is similar to the code in forgetLoop, except that
// it handles SCEVUnknown PHI nodes specially.
- if (ItCount.hasAnyInfo()) {
+ if (BECount.hasAnyInfo()) {
SmallVector<Instruction *, 16> Worklist;
PushLoopPHIs(L, Worklist);
}
}
+/// forgetValue - This method should be called by the client when it has
+/// changed a value in a way that may effect its value, or which may
+/// disconnect it from a def-use chain linking it to a loop.
+void ScalarEvolution::forgetValue(Value *V) {
+ Instruction *I = dyn_cast<Instruction>(V);
+ if (!I) return;
+
+ // Drop information about expressions based on loop-header PHIs.
+ SmallVector<Instruction *, 16> Worklist;
+ Worklist.push_back(I);
+
+ SmallPtrSet<Instruction *, 8> Visited;
+ while (!Worklist.empty()) {
+ I = Worklist.pop_back_val();
+ if (!Visited.insert(I)) continue;
+
+ std::map<SCEVCallbackVH, const SCEV *>::iterator It =
+ Scalars.find(static_cast<Value *>(I));
+ if (It != Scalars.end()) {
+ ValuesAtScopes.erase(It->second);
+ Scalars.erase(It);
+ if (PHINode *PN = dyn_cast<PHINode>(I))
+ ConstantEvolutionLoopExitValue.erase(PN);
+ }
+
+ // If there's a SCEVUnknown tying this value into the SCEV
+ // space, remove it from the folding set map. The SCEVUnknown
+ // object and any other SCEV objects which reference it
+ // (transitively) remain allocated, effectively leaked until
+ // the underlying BumpPtrAllocator is freed.
+ //
+ // This permits SCEV pointers to be used as keys in maps
+ // such as the ValuesAtScopes map.
+ FoldingSetNodeID ID;
+ ID.AddInteger(scUnknown);
+ ID.AddPointer(I);
+ void *IP;
+ if (SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) {
+ UniqueSCEVs.RemoveNode(S);
+
+ // This isn't necessary, but we might as well remove the
+ // value from the ValuesAtScopes map too.
+ ValuesAtScopes.erase(S);
+ }
+
+ PushDefUseChildren(I, Worklist);
+ }
+}
+
/// ComputeBackedgeTakenCount - Compute the number of times the backedge
/// of the specified loop will execute.
ScalarEvolution::BackedgeTakenInfo
return getCouldNotCompute();
}
- // Procede to the next level to examine the exit condition expression.
+ // Proceed to the next level to examine the exit condition expression.
return ComputeBackedgeTakenCountFromExitCond(L, ExitBr->getCondition(),
ExitBr->getSuccessor(0),
ExitBr->getSuccessor(1));
}
// With an icmp, it may be feasible to compute an exact backedge-taken count.
- // Procede to the next level to examine the icmp.
+ // Proceed to the next level to examine the icmp.
if (ICmpInst *ExitCondICmp = dyn_cast<ICmpInst>(ExitCond))
return ComputeBackedgeTakenCountFromExitCondICmp(L, ExitCondICmp, TBB, FBB);
+ // Check for a constant condition. These are normally stripped out by
+ // SimplifyCFG, but ScalarEvolution may be used by a pass which wishes to
+ // preserve the CFG and is temporarily leaving constant conditions
+ // in place.
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(ExitCond)) {
+ if (L->contains(FBB) == !CI->getZExtValue())
+ // The backedge is always taken.
+ return getCouldNotCompute();
+ else
+ // The backedge is never taken.
+ return getConstant(CI->getType(), 0);
+ }
+
// If it's not an integer or pointer comparison then compute it the hard way.
return ComputeBackedgeTakenCountExhaustively(L, ExitCond, !L->contains(TBB));
}
// 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))) {
- const SCEV *ItCnt =
+ BackedgeTakenInfo ItCnt =
ComputeLoadConstantCompareBackedgeTakenCount(LI, RHS, L, Cond);
- if (!isa<SCEVCouldNotCompute>(ItCnt)) {
- unsigned BitWidth = getTypeSizeInBits(ItCnt->getType());
- return BackedgeTakenInfo(ItCnt,
- isa<SCEVConstant>(ItCnt) ? ItCnt :
- getConstant(APInt::getMaxValue(BitWidth)-1));
- }
+ if (ItCnt.hasAnyInfo())
+ return ItCnt;
}
const SCEV *LHS = getSCEV(ExitCond->getOperand(0));
Cond = ICmpInst::getSwappedPredicate(Cond);
}
+ // Simplify the operands before analyzing them.
+ (void)SimplifyICmpOperands(Cond, LHS, RHS);
+
// If we have a comparison of a chrec against a constant, try to use value
// ranges to answer this query.
if (const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS))
switch (Cond) {
case ICmpInst::ICMP_NE: { // while (X != Y)
// Convert to: while (X-Y != 0)
- const SCEV *TC = HowFarToZero(getMinusSCEV(LHS, RHS), L);
- if (!isa<SCEVCouldNotCompute>(TC)) return TC;
+ BackedgeTakenInfo BTI = HowFarToZero(getMinusSCEV(LHS, RHS), L);
+ if (BTI.hasAnyInfo()) return BTI;
break;
}
case ICmpInst::ICMP_EQ: { // while (X == Y)
// Convert to: while (X-Y == 0)
- const SCEV *TC = HowFarToNonZero(getMinusSCEV(LHS, RHS), L);
- if (!isa<SCEVCouldNotCompute>(TC)) return TC;
+ BackedgeTakenInfo BTI = HowFarToNonZero(getMinusSCEV(LHS, RHS), L);
+ if (BTI.hasAnyInfo()) return BTI;
break;
}
case ICmpInst::ICMP_SLT: {
/// ComputeLoadConstantCompareBackedgeTakenCount - Given an exit condition of
/// 'icmp op load X, cst', try to see if we can compute the backedge
/// execution count.
-const SCEV *
+ScalarEvolution::BackedgeTakenInfo
ScalarEvolution::ComputeLoadConstantCompareBackedgeTakenCount(
LoadInst *LI,
Constant *RHS,
if (LI->isVolatile()) return getCouldNotCompute();
// Check to see if the loaded pointer is a getelementptr of a global.
+ // TODO: Use SCEV instead of manually grubbing with GEPs.
GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(LI->getOperand(0));
if (!GEP) return getCouldNotCompute();
// constant or derived from a PHI node themselves.
PHINode *PHI = 0;
for (unsigned Op = 0, e = I->getNumOperands(); Op != e; ++Op)
- if (!(isa<Constant>(I->getOperand(Op)) ||
- isa<GlobalValue>(I->getOperand(Op)))) {
+ if (!isa<Constant>(I->getOperand(Op))) {
PHINode *P = getConstantEvolvingPHI(I->getOperand(Op), L);
if (P == 0) return 0; // Not evolving from PHI
if (PHI == 0)
const TargetData *TD) {
if (isa<PHINode>(V)) return PHIVal;
if (Constant *C = dyn_cast<Constant>(V)) return C;
- if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) return GV;
Instruction *I = cast<Instruction>(V);
- std::vector<Constant*> Operands;
- Operands.resize(I->getNumOperands());
+ std::vector<Constant*> Operands(I->getNumOperands());
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
Operands[i] = EvaluateExpression(I->getOperand(i), PHIVal, TD);
if (I != ConstantEvolutionLoopExitValue.end())
return I->second;
- if (BEs.ugt(APInt(BEs.getBitWidth(),MaxBruteForceIterations)))
+ if (BEs.ugt(MaxBruteForceIterations))
return ConstantEvolutionLoopExitValue[PN] = 0; // Not going to evaluate it.
Constant *&RetVal = ConstantEvolutionLoopExitValue[PN];
return RetVal = 0; // Must be a constant.
Value *BEValue = PN->getIncomingValue(SecondIsBackedge);
- PHINode *PN2 = getConstantEvolvingPHI(BEValue, L);
- if (PN2 != PN)
+ if (getConstantEvolvingPHI(BEValue, L) != PN &&
+ !isa<Constant>(BEValue))
return RetVal = 0; // Not derived from same PHI.
// Execute the loop symbolically to determine the exit value.
PHINode *PN = getConstantEvolvingPHI(Cond, L);
if (PN == 0) return getCouldNotCompute();
- // Since the loop is canonicalized, the PHI node must have two entries. One
- // entry must be a constant (coming in from outside of the loop), and the
+ // If the loop is canonicalized, the PHI will have exactly two entries.
+ // That's the only form we support here.
+ if (PN->getNumIncomingValues() != 2) return getCouldNotCompute();
+
+ // One entry must be a constant (coming in from outside of the loop), and the
// second must be derived from the same PHI.
bool SecondIsBackedge = L->contains(PN->getIncomingBlock(1));
Constant *StartCST =
if (StartCST == 0) return getCouldNotCompute(); // Must be a constant.
Value *BEValue = PN->getIncomingValue(SecondIsBackedge);
- PHINode *PN2 = getConstantEvolvingPHI(BEValue, L);
- if (PN2 != PN) return getCouldNotCompute(); // Not derived from same PHI.
+ if (getConstantEvolvingPHI(BEValue, L) != PN &&
+ !isa<Constant>(BEValue))
+ return getCouldNotCompute(); // Not derived from same PHI.
// Okay, we find a PHI node that defines the trip count of this loop. Execute
// the loop symbolically to determine when the condition gets a value of
// the arguments into constants, and if so, try to constant propagate the
// result. This is particularly useful for computing loop exit values.
if (CanConstantFold(I)) {
- std::vector<Constant*> Operands;
- Operands.reserve(I->getNumOperands());
+ SmallVector<Constant *, 4> Operands;
+ bool MadeImprovement = false;
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
Value *Op = I->getOperand(i);
if (Constant *C = dyn_cast<Constant>(Op)) {
Operands.push_back(C);
- } else {
- // If any of the operands is non-constant and if they are
- // non-integer and non-pointer, don't even try to analyze them
- // with scev techniques.
- if (!isSCEVable(Op->getType()))
- return V;
-
- const SCEV *OpV = getSCEVAtScope(Op, L);
- if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(OpV)) {
- Constant *C = SC->getValue();
- if (C->getType() != Op->getType())
- C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
- Op->getType(),
- false),
- C, Op->getType());
- Operands.push_back(C);
- } else if (const SCEVUnknown *SU = dyn_cast<SCEVUnknown>(OpV)) {
- if (Constant *C = dyn_cast<Constant>(SU->getValue())) {
- if (C->getType() != Op->getType())
- C =
- ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
- Op->getType(),
- false),
- C, Op->getType());
- Operands.push_back(C);
- } else
- return V;
- } else {
- return V;
- }
+ continue;
}
+
+ // If any of the operands is non-constant and if they are
+ // non-integer and non-pointer, don't even try to analyze them
+ // with scev techniques.
+ if (!isSCEVable(Op->getType()))
+ return V;
+
+ const SCEV *OrigV = getSCEV(Op);
+ const SCEV *OpV = getSCEVAtScope(OrigV, L);
+ MadeImprovement |= OrigV != OpV;
+
+ Constant *C = 0;
+ if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(OpV))
+ C = SC->getValue();
+ if (const SCEVUnknown *SU = dyn_cast<SCEVUnknown>(OpV))
+ C = dyn_cast<Constant>(SU->getValue());
+ if (!C) return V;
+ if (C->getType() != Op->getType())
+ C = ConstantExpr::getCast(CastInst::getCastOpcode(C, false,
+ Op->getType(),
+ false),
+ C, Op->getType());
+ Operands.push_back(C);
}
- Constant *C;
- if (const CmpInst *CI = dyn_cast<CmpInst>(I))
- C = ConstantFoldCompareInstOperands(CI->getPredicate(),
- Operands[0], Operands[1], TD);
- else
- C = ConstantFoldInstOperands(I->getOpcode(), I->getType(),
- &Operands[0], Operands.size(), TD);
- return getSCEV(C);
+ // Check to see if getSCEVAtScope actually made an improvement.
+ if (MadeImprovement) {
+ Constant *C = 0;
+ if (const CmpInst *CI = dyn_cast<CmpInst>(I))
+ C = ConstantFoldCompareInstOperands(CI->getPredicate(),
+ Operands[0], Operands[1], TD);
+ else
+ C = ConstantFoldInstOperands(I->getOpcode(), I->getType(),
+ &Operands[0], Operands.size(), TD);
+ if (!C) return V;
+ return getSCEV(C);
+ }
}
}
// If this is a loop recurrence for a loop that does not contain L, then we
// are dealing with the final value computed by the loop.
if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(V)) {
- if (!L || !AddRec->getLoop()->contains(L)) {
+ // First, attempt to evaluate each operand.
+ // Avoid performing the look-up in the common case where the specified
+ // expression has no loop-variant portions.
+ for (unsigned i = 0, e = AddRec->getNumOperands(); i != e; ++i) {
+ const SCEV *OpAtScope = getSCEVAtScope(AddRec->getOperand(i), L);
+ if (OpAtScope == AddRec->getOperand(i))
+ continue;
+
+ // Okay, at least one of these operands is loop variant but might be
+ // foldable. Build a new instance of the folded commutative expression.
+ SmallVector<const SCEV *, 8> NewOps(AddRec->op_begin(),
+ AddRec->op_begin()+i);
+ NewOps.push_back(OpAtScope);
+ for (++i; i != e; ++i)
+ NewOps.push_back(getSCEVAtScope(AddRec->getOperand(i), L));
+
+ AddRec = cast<SCEVAddRecExpr>(getAddRecExpr(NewOps, AddRec->getLoop()));
+ break;
+ }
+
+ // If the scope is outside the addrec's loop, evaluate it by using the
+ // loop exit value of the addrec.
+ if (!AddRec->getLoop()->contains(L)) {
// To evaluate this recurrence, we need to know how many times the AddRec
// loop iterates. Compute this now.
const SCEV *BackedgeTakenCount = getBackedgeTakenCount(AddRec->getLoop());
// Then, evaluate the AddRec.
return AddRec->evaluateAtIteration(BackedgeTakenCount, *this);
}
+
return AddRec;
}
return getTruncateExpr(Op, Cast->getType());
}
- if (isa<SCEVTargetDataConstant>(V))
- return V;
-
llvm_unreachable("Unknown SCEV type!");
return 0;
}
/// HowFarToZero - Return the number of times a backedge comparing the specified
/// value to zero will execute. If not computable, return CouldNotCompute.
-const SCEV *ScalarEvolution::HowFarToZero(const SCEV *V, const Loop *L) {
+ScalarEvolution::BackedgeTakenInfo
+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.
-StartC->getValue()->getValue(),
*this);
}
- } else if (AddRec->isQuadratic() && AddRec->getType()->isInteger()) {
+ } else if (AddRec->isQuadratic() && AddRec->getType()->isIntegerTy()) {
// If this is a quadratic (3-term) AddRec {L,+,M,+,N}, find the roots of
// the quadratic equation to solve it.
std::pair<const SCEV *,const SCEV *> Roots = SolveQuadraticEquation(AddRec,
/// HowFarToNonZero - Return the number of times a backedge checking the
/// specified value for nonzero will execute. If not computable, return
/// CouldNotCompute
-const SCEV *ScalarEvolution::HowFarToNonZero(const SCEV *V, const Loop *L) {
+ScalarEvolution::BackedgeTakenInfo
+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.
// already. If so, the backedge will execute zero times.
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(V)) {
if (!C->getValue()->isNullValue())
- return getIntegerSCEV(0, C->getType());
+ return getConstant(C->getType(), 0);
return getCouldNotCompute(); // Otherwise it will loop infinitely.
}
return getCouldNotCompute();
}
-/// getLoopPredecessor - If the given loop's header has exactly one unique
-/// predecessor outside the loop, return it. Otherwise return null.
-///
-BasicBlock *ScalarEvolution::getLoopPredecessor(const Loop *L) {
- BasicBlock *Header = L->getHeader();
- BasicBlock *Pred = 0;
- for (pred_iterator PI = pred_begin(Header), E = pred_end(Header);
- PI != E; ++PI)
- if (!L->contains(*PI)) {
- if (Pred && Pred != *PI) return 0; // Multiple predecessors.
- Pred = *PI;
- }
- return Pred;
-}
-
/// getPredecessorWithUniqueSuccessorForBB - Return a predecessor of BB
/// (which may not be an immediate predecessor) which has exactly one
/// successor from which BB is reachable, or null if no such block is
/// found.
///
-BasicBlock *
+std::pair<BasicBlock *, BasicBlock *>
ScalarEvolution::getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB) {
// If the block has a unique predecessor, then there is no path from the
// predecessor to the block that does not go through the direct edge
// from the predecessor to the block.
if (BasicBlock *Pred = BB->getSinglePredecessor())
- return Pred;
+ return std::make_pair(Pred, BB);
// A loop's header is defined to be a block that dominates the loop.
// If the header has a unique predecessor outside the loop, it must be
// a block that has exactly one successor that can reach the loop.
if (Loop *L = LI->getLoopFor(BB))
- return getLoopPredecessor(L);
+ return std::make_pair(L->getLoopPredecessor(), L->getHeader());
- return 0;
+ return std::pair<BasicBlock *, BasicBlock *>();
}
/// HasSameValue - SCEV structural equivalence is usually sufficient for
return false;
}
+/// SimplifyICmpOperands - Simplify LHS and RHS in a comparison with
+/// predicate Pred. Return true iff any changes were made.
+///
+bool ScalarEvolution::SimplifyICmpOperands(ICmpInst::Predicate &Pred,
+ const SCEV *&LHS, const SCEV *&RHS) {
+ bool Changed = false;
+
+ // Canonicalize a constant to the right side.
+ if (const SCEVConstant *LHSC = dyn_cast<SCEVConstant>(LHS)) {
+ // Check for both operands constant.
+ if (const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS)) {
+ if (ConstantExpr::getICmp(Pred,
+ LHSC->getValue(),
+ RHSC->getValue())->isNullValue())
+ goto trivially_false;
+ else
+ goto trivially_true;
+ }
+ // Otherwise swap the operands to put the constant on the right.
+ std::swap(LHS, RHS);
+ Pred = ICmpInst::getSwappedPredicate(Pred);
+ Changed = true;
+ }
+
+ // If we're comparing an addrec with a value which is loop-invariant in the
+ // addrec's loop, put the addrec on the left. Also make a dominance check,
+ // as both operands could be addrecs loop-invariant in each other's loop.
+ if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(RHS)) {
+ const Loop *L = AR->getLoop();
+ if (LHS->isLoopInvariant(L) && LHS->properlyDominates(L->getHeader(), DT)) {
+ std::swap(LHS, RHS);
+ Pred = ICmpInst::getSwappedPredicate(Pred);
+ Changed = true;
+ }
+ }
+
+ // If there's a constant operand, canonicalize comparisons with boundary
+ // cases, and canonicalize *-or-equal comparisons to regular comparisons.
+ if (const SCEVConstant *RC = dyn_cast<SCEVConstant>(RHS)) {
+ const APInt &RA = RC->getValue()->getValue();
+ switch (Pred) {
+ default: llvm_unreachable("Unexpected ICmpInst::Predicate value!");
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_NE:
+ break;
+ case ICmpInst::ICMP_UGE:
+ if ((RA - 1).isMinValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ RHS = getConstant(RA - 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMaxValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ Changed = true;
+ break;
+ }
+ if (RA.isMinValue()) goto trivially_true;
+
+ Pred = ICmpInst::ICMP_UGT;
+ RHS = getConstant(RA - 1);
+ Changed = true;
+ break;
+ case ICmpInst::ICMP_ULE:
+ if ((RA + 1).isMaxValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ RHS = getConstant(RA + 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMinValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ Changed = true;
+ break;
+ }
+ if (RA.isMaxValue()) goto trivially_true;
+
+ Pred = ICmpInst::ICMP_ULT;
+ RHS = getConstant(RA + 1);
+ Changed = true;
+ break;
+ case ICmpInst::ICMP_SGE:
+ if ((RA - 1).isMinSignedValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ RHS = getConstant(RA - 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMaxSignedValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ Changed = true;
+ break;
+ }
+ if (RA.isMinSignedValue()) goto trivially_true;
+
+ Pred = ICmpInst::ICMP_SGT;
+ RHS = getConstant(RA - 1);
+ Changed = true;
+ break;
+ case ICmpInst::ICMP_SLE:
+ if ((RA + 1).isMaxSignedValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ RHS = getConstant(RA + 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMinSignedValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ Changed = true;
+ break;
+ }
+ if (RA.isMaxSignedValue()) goto trivially_true;
+
+ Pred = ICmpInst::ICMP_SLT;
+ RHS = getConstant(RA + 1);
+ Changed = true;
+ break;
+ case ICmpInst::ICMP_UGT:
+ if (RA.isMinValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ Changed = true;
+ break;
+ }
+ if ((RA + 1).isMaxValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ RHS = getConstant(RA + 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMaxValue()) goto trivially_false;
+ break;
+ case ICmpInst::ICMP_ULT:
+ if (RA.isMaxValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ Changed = true;
+ break;
+ }
+ if ((RA - 1).isMinValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ RHS = getConstant(RA - 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMinValue()) goto trivially_false;
+ break;
+ case ICmpInst::ICMP_SGT:
+ if (RA.isMinSignedValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ Changed = true;
+ break;
+ }
+ if ((RA + 1).isMaxSignedValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ RHS = getConstant(RA + 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMaxSignedValue()) goto trivially_false;
+ break;
+ case ICmpInst::ICMP_SLT:
+ if (RA.isMaxSignedValue()) {
+ Pred = ICmpInst::ICMP_NE;
+ Changed = true;
+ break;
+ }
+ if ((RA - 1).isMinSignedValue()) {
+ Pred = ICmpInst::ICMP_EQ;
+ RHS = getConstant(RA - 1);
+ Changed = true;
+ break;
+ }
+ if (RA.isMinSignedValue()) goto trivially_false;
+ break;
+ }
+ }
+
+ // Check for obvious equality.
+ if (HasSameValue(LHS, RHS)) {
+ if (ICmpInst::isTrueWhenEqual(Pred))
+ goto trivially_true;
+ if (ICmpInst::isFalseWhenEqual(Pred))
+ goto trivially_false;
+ }
+
+ // If possible, canonicalize GE/LE comparisons to GT/LT comparisons, by
+ // adding or subtracting 1 from one of the operands.
+ switch (Pred) {
+ case ICmpInst::ICMP_SLE:
+ if (!getSignedRange(RHS).getSignedMax().isMaxSignedValue()) {
+ RHS = getAddExpr(getConstant(RHS->getType(), 1, true), RHS,
+ /*HasNUW=*/false, /*HasNSW=*/true);
+ Pred = ICmpInst::ICMP_SLT;
+ Changed = true;
+ } else if (!getSignedRange(LHS).getSignedMin().isMinSignedValue()) {
+ LHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), LHS,
+ /*HasNUW=*/false, /*HasNSW=*/true);
+ Pred = ICmpInst::ICMP_SLT;
+ Changed = true;
+ }
+ break;
+ case ICmpInst::ICMP_SGE:
+ if (!getSignedRange(RHS).getSignedMin().isMinSignedValue()) {
+ RHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), RHS,
+ /*HasNUW=*/false, /*HasNSW=*/true);
+ Pred = ICmpInst::ICMP_SGT;
+ Changed = true;
+ } else if (!getSignedRange(LHS).getSignedMax().isMaxSignedValue()) {
+ LHS = getAddExpr(getConstant(RHS->getType(), 1, true), LHS,
+ /*HasNUW=*/false, /*HasNSW=*/true);
+ Pred = ICmpInst::ICMP_SGT;
+ Changed = true;
+ }
+ break;
+ case ICmpInst::ICMP_ULE:
+ if (!getUnsignedRange(RHS).getUnsignedMax().isMaxValue()) {
+ RHS = getAddExpr(getConstant(RHS->getType(), 1, true), RHS,
+ /*HasNUW=*/true, /*HasNSW=*/false);
+ Pred = ICmpInst::ICMP_ULT;
+ Changed = true;
+ } else if (!getUnsignedRange(LHS).getUnsignedMin().isMinValue()) {
+ LHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), LHS,
+ /*HasNUW=*/true, /*HasNSW=*/false);
+ Pred = ICmpInst::ICMP_ULT;
+ Changed = true;
+ }
+ break;
+ case ICmpInst::ICMP_UGE:
+ if (!getUnsignedRange(RHS).getUnsignedMin().isMinValue()) {
+ RHS = getAddExpr(getConstant(RHS->getType(), (uint64_t)-1, true), RHS,
+ /*HasNUW=*/true, /*HasNSW=*/false);
+ Pred = ICmpInst::ICMP_UGT;
+ Changed = true;
+ } else if (!getUnsignedRange(LHS).getUnsignedMax().isMaxValue()) {
+ LHS = getAddExpr(getConstant(RHS->getType(), 1, true), LHS,
+ /*HasNUW=*/true, /*HasNSW=*/false);
+ Pred = ICmpInst::ICMP_UGT;
+ Changed = true;
+ }
+ break;
+ default:
+ break;
+ }
+
+ // TODO: More simplifications are possible here.
+
+ return Changed;
+
+trivially_true:
+ // Return 0 == 0.
+ LHS = RHS = getConstant(Type::getInt1Ty(getContext()), 0);
+ Pred = ICmpInst::ICMP_EQ;
+ return true;
+
+trivially_false:
+ // Return 0 != 0.
+ LHS = RHS = getConstant(Type::getInt1Ty(getContext()), 0);
+ Pred = ICmpInst::ICMP_NE;
+ return true;
+}
+
bool ScalarEvolution::isKnownNegative(const SCEV *S) {
return getSignedRange(S).getSignedMax().isNegative();
}
bool ScalarEvolution::isKnownPredicate(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS) {
+ // Canonicalize the inputs first.
+ (void)SimplifyICmpOperands(Pred, LHS, RHS);
+
+ // If LHS or RHS is an addrec, check to see if the condition is true in
+ // every iteration of the loop.
+ if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(LHS))
+ if (isLoopEntryGuardedByCond(
+ AR->getLoop(), Pred, AR->getStart(), RHS) &&
+ isLoopBackedgeGuardedByCond(
+ AR->getLoop(), Pred, AR->getPostIncExpr(*this), RHS))
+ return true;
+ if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(RHS))
+ if (isLoopEntryGuardedByCond(
+ AR->getLoop(), Pred, LHS, AR->getStart()) &&
+ isLoopBackedgeGuardedByCond(
+ AR->getLoop(), Pred, LHS, AR->getPostIncExpr(*this)))
+ return true;
+
+ // Otherwise see what can be done with known constant ranges.
+ return isKnownPredicateWithRanges(Pred, LHS, RHS);
+}
+bool
+ScalarEvolution::isKnownPredicateWithRanges(ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS) {
if (HasSameValue(LHS, RHS))
return ICmpInst::isTrueWhenEqual(Pred);
+ // This code is split out from isKnownPredicate because it is called from
+ // within isLoopEntryGuardedByCond.
switch (Pred) {
default:
llvm_unreachable("Unexpected ICmpInst::Predicate value!");
LoopContinuePredicate->getSuccessor(0) != L->getHeader());
}
-/// isLoopGuardedByCond - Test whether entry to the loop is protected
+/// isLoopEntryGuardedByCond - Test whether entry to the loop is protected
/// by a conditional between LHS and RHS. This is used to help avoid max
/// expressions in loop trip counts, and to eliminate casts.
bool
-ScalarEvolution::isLoopGuardedByCond(const Loop *L,
- ICmpInst::Predicate Pred,
- const SCEV *LHS, const SCEV *RHS) {
+ScalarEvolution::isLoopEntryGuardedByCond(const Loop *L,
+ ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS) {
// Interpret a null as meaning no loop, where there is obviously no guard
// (interprocedural conditions notwithstanding).
if (!L) return false;
- BasicBlock *Predecessor = getLoopPredecessor(L);
- BasicBlock *PredecessorDest = L->getHeader();
-
// Starting at the loop predecessor, climb up the predecessor chain, as long
// as there are predecessors that can be found that have unique successors
// leading to the original header.
- for (; Predecessor;
- PredecessorDest = Predecessor,
- Predecessor = getPredecessorWithUniqueSuccessorForBB(Predecessor)) {
+ for (std::pair<BasicBlock *, BasicBlock *>
+ Pair(L->getLoopPredecessor(), L->getHeader());
+ Pair.first;
+ Pair = getPredecessorWithUniqueSuccessorForBB(Pair.first)) {
BranchInst *LoopEntryPredicate =
- dyn_cast<BranchInst>(Predecessor->getTerminator());
+ dyn_cast<BranchInst>(Pair.first->getTerminator());
if (!LoopEntryPredicate ||
LoopEntryPredicate->isUnconditional())
continue;
if (isImpliedCond(LoopEntryPredicate->getCondition(), Pred, LHS, RHS,
- LoopEntryPredicate->getSuccessor(0) != PredecessorDest))
+ LoopEntryPredicate->getSuccessor(0) != Pair.second))
return true;
}
ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS,
bool Inverse) {
- // Recursivly handle And and Or conditions.
+ // Recursively handle And and Or conditions.
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(CondValue)) {
if (BO->getOpcode() == Instruction::And) {
if (!Inverse)
// Canonicalize the query to match the way instcombine will have
// canonicalized the comparison.
- // First, put a constant operand on the right.
- if (isa<SCEVConstant>(LHS)) {
- std::swap(LHS, RHS);
- Pred = ICmpInst::getSwappedPredicate(Pred);
- }
- // Then, canonicalize comparisons with boundary cases.
- if (const SCEVConstant *RC = dyn_cast<SCEVConstant>(RHS)) {
- const APInt &RA = RC->getValue()->getValue();
- switch (Pred) {
- default: llvm_unreachable("Unexpected ICmpInst::Predicate value!");
- case ICmpInst::ICMP_EQ:
- case ICmpInst::ICMP_NE:
- break;
- case ICmpInst::ICMP_UGE:
- if ((RA - 1).isMinValue()) {
- Pred = ICmpInst::ICMP_NE;
- RHS = getConstant(RA - 1);
- break;
- }
- if (RA.isMaxValue()) {
- Pred = ICmpInst::ICMP_EQ;
- break;
- }
- if (RA.isMinValue()) return true;
- break;
- case ICmpInst::ICMP_ULE:
- if ((RA + 1).isMaxValue()) {
- Pred = ICmpInst::ICMP_NE;
- RHS = getConstant(RA + 1);
- break;
- }
- if (RA.isMinValue()) {
- Pred = ICmpInst::ICMP_EQ;
- break;
- }
- if (RA.isMaxValue()) return true;
- break;
- case ICmpInst::ICMP_SGE:
- if ((RA - 1).isMinSignedValue()) {
- Pred = ICmpInst::ICMP_NE;
- RHS = getConstant(RA - 1);
- break;
- }
- if (RA.isMaxSignedValue()) {
- Pred = ICmpInst::ICMP_EQ;
- break;
- }
- if (RA.isMinSignedValue()) return true;
- break;
- case ICmpInst::ICMP_SLE:
- if ((RA + 1).isMaxSignedValue()) {
- Pred = ICmpInst::ICMP_NE;
- RHS = getConstant(RA + 1);
- break;
- }
- if (RA.isMinSignedValue()) {
- Pred = ICmpInst::ICMP_EQ;
- break;
- }
- if (RA.isMaxSignedValue()) return true;
- break;
- case ICmpInst::ICMP_UGT:
- if (RA.isMinValue()) {
- Pred = ICmpInst::ICMP_NE;
- break;
- }
- if ((RA + 1).isMaxValue()) {
- Pred = ICmpInst::ICMP_EQ;
- RHS = getConstant(RA + 1);
- break;
- }
- if (RA.isMaxValue()) return false;
- break;
- case ICmpInst::ICMP_ULT:
- if (RA.isMaxValue()) {
- Pred = ICmpInst::ICMP_NE;
- break;
- }
- if ((RA - 1).isMinValue()) {
- Pred = ICmpInst::ICMP_EQ;
- RHS = getConstant(RA - 1);
- break;
- }
- if (RA.isMinValue()) return false;
- break;
- case ICmpInst::ICMP_SGT:
- if (RA.isMinSignedValue()) {
- Pred = ICmpInst::ICMP_NE;
- break;
- }
- if ((RA + 1).isMaxSignedValue()) {
- Pred = ICmpInst::ICMP_EQ;
- RHS = getConstant(RA + 1);
- break;
- }
- if (RA.isMaxSignedValue()) return false;
- break;
- case ICmpInst::ICMP_SLT:
- if (RA.isMaxSignedValue()) {
- Pred = ICmpInst::ICMP_NE;
- break;
- }
- if ((RA - 1).isMinSignedValue()) {
- Pred = ICmpInst::ICMP_EQ;
- RHS = getConstant(RA - 1);
- break;
- }
- if (RA.isMinSignedValue()) return false;
- break;
- }
- }
+ if (SimplifyICmpOperands(Pred, LHS, RHS))
+ if (LHS == RHS)
+ return CmpInst::isTrueWhenEqual(Pred);
+ if (SimplifyICmpOperands(FoundPred, FoundLHS, FoundRHS))
+ if (FoundLHS == FoundRHS)
+ return CmpInst::isFalseWhenEqual(Pred);
// Check to see if we can make the LHS or RHS match.
if (LHS == FoundRHS || RHS == FoundLHS) {
}
/// isImpliedCondOperands - Test whether the condition described by Pred,
-/// LHS, and RHS is true whenever the condition desribed by Pred, FoundLHS,
+/// LHS, and RHS is true whenever the condition described by Pred, FoundLHS,
/// and FoundRHS is true.
bool ScalarEvolution::isImpliedCondOperands(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS,
}
/// isImpliedCondOperandsHelper - Test whether the condition described by
-/// Pred, LHS, and RHS is true whenever the condition desribed by Pred,
+/// Pred, LHS, and RHS is true whenever the condition described by Pred,
/// FoundLHS, and FoundRHS is true.
bool
ScalarEvolution::isImpliedCondOperandsHelper(ICmpInst::Predicate Pred,
break;
case ICmpInst::ICMP_SLT:
case ICmpInst::ICMP_SLE:
- if (isKnownPredicate(ICmpInst::ICMP_SLE, LHS, FoundLHS) &&
- isKnownPredicate(ICmpInst::ICMP_SGE, RHS, FoundRHS))
+ if (isKnownPredicateWithRanges(ICmpInst::ICMP_SLE, LHS, FoundLHS) &&
+ isKnownPredicateWithRanges(ICmpInst::ICMP_SGE, RHS, FoundRHS))
return true;
break;
case ICmpInst::ICMP_SGT:
case ICmpInst::ICMP_SGE:
- if (isKnownPredicate(ICmpInst::ICMP_SGE, LHS, FoundLHS) &&
- isKnownPredicate(ICmpInst::ICMP_SLE, RHS, FoundRHS))
+ if (isKnownPredicateWithRanges(ICmpInst::ICMP_SGE, LHS, FoundLHS) &&
+ isKnownPredicateWithRanges(ICmpInst::ICMP_SLE, RHS, FoundRHS))
return true;
break;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
- if (isKnownPredicate(ICmpInst::ICMP_ULE, LHS, FoundLHS) &&
- isKnownPredicate(ICmpInst::ICMP_UGE, RHS, FoundRHS))
+ if (isKnownPredicateWithRanges(ICmpInst::ICMP_ULE, LHS, FoundLHS) &&
+ isKnownPredicateWithRanges(ICmpInst::ICMP_UGE, RHS, FoundRHS))
return true;
break;
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_UGE:
- if (isKnownPredicate(ICmpInst::ICMP_UGE, LHS, FoundLHS) &&
- isKnownPredicate(ICmpInst::ICMP_ULE, RHS, FoundRHS))
+ if (isKnownPredicateWithRanges(ICmpInst::ICMP_UGE, LHS, FoundLHS) &&
+ isKnownPredicateWithRanges(ICmpInst::ICMP_ULE, RHS, FoundRHS))
return true;
break;
}
const SCEV *End,
const SCEV *Step,
bool NoWrap) {
+ assert(!isKnownNegative(Step) &&
+ "This code doesn't handle negative strides yet!");
+
const Type *Ty = Start->getType();
- const SCEV *NegOne = getIntegerSCEV(-1, Ty);
+ const SCEV *NegOne = getConstant(Ty, (uint64_t)-1);
const SCEV *Diff = getMinusSCEV(End, Start);
const SCEV *RoundUp = getAddExpr(Step, NegOne);
AddRec->hasNoUnsignedWrap();
if (AddRec->isAffine()) {
- // FORNOW: We only support unit strides.
unsigned BitWidth = getTypeSizeInBits(AddRec->getType());
const SCEV *Step = AddRec->getStepRecurrence(*this);
- // TODO: handle non-constant strides.
- const SCEVConstant *CStep = dyn_cast<SCEVConstant>(Step);
- if (!CStep || CStep->isZero())
+ if (Step->isZero())
return getCouldNotCompute();
- if (CStep->isOne()) {
+ if (Step->isOne()) {
// With unit stride, the iteration never steps past the limit value.
- } else if (CStep->getValue()->getValue().isStrictlyPositive()) {
- if (NoWrap) {
- // We know the iteration won't step past the maximum value for its type.
- ;
- } else if (const SCEVConstant *CLimit = dyn_cast<SCEVConstant>(RHS)) {
- // Test whether a positive iteration iteration can step past the limit
- // value and past the maximum value for its type in a single step.
- if (isSigned) {
- APInt Max = APInt::getSignedMaxValue(BitWidth);
- if ((Max - CStep->getValue()->getValue())
- .slt(CLimit->getValue()->getValue()))
- return getCouldNotCompute();
- } else {
- APInt Max = APInt::getMaxValue(BitWidth);
- if ((Max - CStep->getValue()->getValue())
- .ult(CLimit->getValue()->getValue()))
- return getCouldNotCompute();
- }
- } else
- // TODO: handle non-constant limit values below.
- return getCouldNotCompute();
+ } else if (isKnownPositive(Step)) {
+ // Test whether a positive iteration can step past the limit
+ // value and past the maximum value for its type in a single step.
+ // Note that it's not sufficient to check NoWrap here, because even
+ // though the value after a wrap is undefined, it's not undefined
+ // behavior, so if wrap does occur, the loop could either terminate or
+ // loop infinitely, but in either case, the loop is guaranteed to
+ // iterate at least until the iteration where the wrapping occurs.
+ const SCEV *One = getConstant(Step->getType(), 1);
+ if (isSigned) {
+ APInt Max = APInt::getSignedMaxValue(BitWidth);
+ if ((Max - getSignedRange(getMinusSCEV(Step, One)).getSignedMax())
+ .slt(getSignedRange(RHS).getSignedMax()))
+ return getCouldNotCompute();
+ } else {
+ APInt Max = APInt::getMaxValue(BitWidth);
+ if ((Max - getUnsignedRange(getMinusSCEV(Step, One)).getUnsignedMax())
+ .ult(getUnsignedRange(RHS).getUnsignedMax()))
+ return getCouldNotCompute();
+ }
} else
- // TODO: handle negative strides below.
+ // TODO: Handle negative strides here and below.
return getCouldNotCompute();
// We know the LHS is of the form {n,+,s} and the RHS is some loop-invariant
// only know that it will execute (max(m,n)-n)/s times. In both cases,
// the division must round up.
const SCEV *End = RHS;
- if (!isLoopGuardedByCond(L,
- isSigned ? ICmpInst::ICMP_SLT :
- ICmpInst::ICMP_ULT,
- getMinusSCEV(Start, Step), RHS))
+ if (!isLoopEntryGuardedByCond(L,
+ isSigned ? ICmpInst::ICMP_SLT :
+ ICmpInst::ICMP_ULT,
+ getMinusSCEV(Start, Step), RHS))
End = isSigned ? getSMaxExpr(RHS, Start)
: getUMaxExpr(RHS, Start);
getSignedRange(End).getSignedMax() :
getUnsignedRange(End).getUnsignedMax());
+ // If MaxEnd is within a step of the maximum integer value in its type,
+ // adjust it down to the minimum value which would produce the same effect.
+ // This allows the subsequent ceiling division of (N+(step-1))/step to
+ // compute the correct value.
+ const SCEV *StepMinusOne = getMinusSCEV(Step,
+ getConstant(Step->getType(), 1));
+ MaxEnd = isSigned ?
+ getSMinExpr(MaxEnd,
+ getMinusSCEV(getConstant(APInt::getSignedMaxValue(BitWidth)),
+ StepMinusOne)) :
+ getUMinExpr(MaxEnd,
+ getMinusSCEV(getConstant(APInt::getMaxValue(BitWidth)),
+ StepMinusOne));
+
// Finally, we subtract these two values and divide, rounding up, to get
// the number of times the backedge is executed.
const SCEV *BECount = getBECount(Start, End, Step, NoWrap);
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(getStart()))
if (!SC->getValue()->isZero()) {
SmallVector<const SCEV *, 4> Operands(op_begin(), op_end());
- Operands[0] = SE.getIntegerSCEV(0, SC->getType());
+ Operands[0] = SE.getConstant(SC->getType(), 0);
const SCEV *Shifted = SE.getAddRecExpr(Operands, getLoop());
if (const SCEVAddRecExpr *ShiftedAddRec =
dyn_cast<SCEVAddRecExpr>(Shifted))
// iteration exits.
unsigned BitWidth = SE.getTypeSizeInBits(getType());
if (!Range.contains(APInt(BitWidth, 0)))
- return SE.getIntegerSCEV(0, getType());
+ return SE.getConstant(getType(), 0);
if (isAffine()) {
// If this is an affine expression then we have this situation:
bool ScalarEvolution::runOnFunction(Function &F) {
this->F = &F;
LI = &getAnalysis<LoopInfo>();
- DT = &getAnalysis<DominatorTree>();
TD = getAnalysisIfAvailable<TargetData>();
+ DT = &getAnalysis<DominatorTree>();
return false;
}
}
void ScalarEvolution::print(raw_ostream &OS, const Module *) const {
- // ScalarEvolution's implementaiton of the print method is to print
+ // ScalarEvolution's implementation of the print method is to print
// out SCEV values of all instructions that are interesting. Doing
// this potentially causes it to create new SCEV objects though,
// which technically conflicts with the const qualifier. This isn't
WriteAsOperand(OS, F, /*PrintType=*/false);
OS << "\n";
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I)
- if (isSCEVable(I->getType())) {
+ if (isSCEVable(I->getType()) && !isa<CmpInst>(*I)) {
OS << *I << '\n';
OS << " --> ";
const SCEV *SV = SE.getSCEV(&*I);
projects / oota-llvm.git / blobdiff