#include "llvm/Operator.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Assembly/Writer.h"
// Implementation of the SCEV class.
//
-SCEV::~SCEV() {}
-
void SCEV::dump() const {
print(dbgs());
dbgs() << '\n';
}
+void SCEV::print(raw_ostream &OS) const {
+ switch (getSCEVType()) {
+ case scConstant:
+ WriteAsOperand(OS, cast<SCEVConstant>(this)->getValue(), false);
+ return;
+ case scTruncate: {
+ const SCEVTruncateExpr *Trunc = cast<SCEVTruncateExpr>(this);
+ const SCEV *Op = Trunc->getOperand();
+ OS << "(trunc " << *Op->getType() << " " << *Op << " to "
+ << *Trunc->getType() << ")";
+ return;
+ }
+ case scZeroExtend: {
+ const SCEVZeroExtendExpr *ZExt = cast<SCEVZeroExtendExpr>(this);
+ const SCEV *Op = ZExt->getOperand();
+ OS << "(zext " << *Op->getType() << " " << *Op << " to "
+ << *ZExt->getType() << ")";
+ return;
+ }
+ case scSignExtend: {
+ const SCEVSignExtendExpr *SExt = cast<SCEVSignExtendExpr>(this);
+ const SCEV *Op = SExt->getOperand();
+ OS << "(sext " << *Op->getType() << " " << *Op << " to "
+ << *SExt->getType() << ")";
+ return;
+ }
+ case scAddRecExpr: {
+ const SCEVAddRecExpr *AR = cast<SCEVAddRecExpr>(this);
+ OS << "{" << *AR->getOperand(0);
+ for (unsigned i = 1, e = AR->getNumOperands(); i != e; ++i)
+ OS << ",+," << *AR->getOperand(i);
+ OS << "}<";
+ WriteAsOperand(OS, AR->getLoop()->getHeader(), /*PrintType=*/false);
+ OS << ">";
+ return;
+ }
+ case scAddExpr:
+ case scMulExpr:
+ case scUMaxExpr:
+ case scSMaxExpr: {
+ const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(this);
+ const char *OpStr = 0;
+ switch (NAry->getSCEVType()) {
+ case scAddExpr: OpStr = " + "; break;
+ case scMulExpr: OpStr = " * "; break;
+ case scUMaxExpr: OpStr = " umax "; break;
+ case scSMaxExpr: OpStr = " smax "; break;
+ }
+ OS << "(";
+ for (SCEVNAryExpr::op_iterator I = NAry->op_begin(), E = NAry->op_end();
+ I != E; ++I) {
+ OS << **I;
+ if (llvm::next(I) != E)
+ OS << OpStr;
+ }
+ OS << ")";
+ return;
+ }
+ case scUDivExpr: {
+ const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(this);
+ OS << "(" << *UDiv->getLHS() << " /u " << *UDiv->getRHS() << ")";
+ return;
+ }
+ case scUnknown: {
+ const SCEVUnknown *U = cast<SCEVUnknown>(this);
+ const Type *AllocTy;
+ if (U->isSizeOf(AllocTy)) {
+ OS << "sizeof(" << *AllocTy << ")";
+ return;
+ }
+ if (U->isAlignOf(AllocTy)) {
+ OS << "alignof(" << *AllocTy << ")";
+ return;
+ }
+
+ const Type *CTy;
+ Constant *FieldNo;
+ if (U->isOffsetOf(CTy, FieldNo)) {
+ OS << "offsetof(" << *CTy << ", ";
+ WriteAsOperand(OS, FieldNo, false);
+ OS << ")";
+ return;
+ }
+
+ // Otherwise just print it normally.
+ WriteAsOperand(OS, U->getValue(), false);
+ return;
+ }
+ case scCouldNotCompute:
+ OS << "***COULDNOTCOMPUTE***";
+ return;
+ default: break;
+ }
+ llvm_unreachable("Unknown SCEV kind!");
+}
+
+const Type *SCEV::getType() const {
+ switch (getSCEVType()) {
+ case scConstant:
+ return cast<SCEVConstant>(this)->getType();
+ case scTruncate:
+ case scZeroExtend:
+ case scSignExtend:
+ return cast<SCEVCastExpr>(this)->getType();
+ case scAddRecExpr:
+ case scMulExpr:
+ case scUMaxExpr:
+ case scSMaxExpr:
+ return cast<SCEVNAryExpr>(this)->getType();
+ case scAddExpr:
+ return cast<SCEVAddExpr>(this)->getType();
+ case scUDivExpr:
+ return cast<SCEVUDivExpr>(this)->getType();
+ case scUnknown:
+ return cast<SCEVUnknown>(this)->getType();
+ case scCouldNotCompute:
+ llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
+ return 0;
+ default: break;
+ }
+ llvm_unreachable("Unknown SCEV kind!");
+ return 0;
+}
+
bool SCEV::isZero() const {
if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(this))
return SC->getValue()->isZero();
SCEVCouldNotCompute::SCEVCouldNotCompute() :
SCEV(FoldingSetNodeIDRef(), scCouldNotCompute) {}
-bool SCEVCouldNotCompute::isLoopInvariant(const Loop *L) const {
- llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
- return false;
-}
-
-const Type *SCEVCouldNotCompute::getType() const {
- llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
- return 0;
-}
-
-bool SCEVCouldNotCompute::hasComputableLoopEvolution(const Loop *L) const {
- llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
- return false;
-}
-
-bool SCEVCouldNotCompute::hasOperand(const SCEV *) const {
- llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
- return false;
-}
-
-void SCEVCouldNotCompute::print(raw_ostream &OS) const {
- OS << "***COULDNOTCOMPUTE***";
-}
-
bool SCEVCouldNotCompute::classof(const SCEV *S) {
return S->getSCEVType() == scCouldNotCompute;
}
return getConstant(ConstantInt::get(ITy, V, isSigned));
}
-const Type *SCEVConstant::getType() const { return V->getType(); }
-
-void SCEVConstant::print(raw_ostream &OS) const {
- WriteAsOperand(OS, V, false);
-}
-
SCEVCastExpr::SCEVCastExpr(const FoldingSetNodeIDRef ID,
unsigned SCEVTy, const SCEV *op, const Type *ty)
: SCEV(ID, SCEVTy), Op(op), Ty(ty) {}
-bool SCEVCastExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
- return Op->dominates(BB, DT);
-}
-
-bool SCEVCastExpr::properlyDominates(BasicBlock *BB, DominatorTree *DT) const {
- return Op->properlyDominates(BB, DT);
-}
-
SCEVTruncateExpr::SCEVTruncateExpr(const FoldingSetNodeIDRef ID,
const SCEV *op, const Type *ty)
: SCEVCastExpr(ID, scTruncate, op, ty) {
"Cannot truncate non-integer value!");
}
-void SCEVTruncateExpr::print(raw_ostream &OS) const {
- OS << "(trunc " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
-}
-
SCEVZeroExtendExpr::SCEVZeroExtendExpr(const FoldingSetNodeIDRef ID,
const SCEV *op, const Type *ty)
: SCEVCastExpr(ID, scZeroExtend, op, ty) {
"Cannot zero extend non-integer value!");
}
-void SCEVZeroExtendExpr::print(raw_ostream &OS) const {
- OS << "(zext " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
-}
-
SCEVSignExtendExpr::SCEVSignExtendExpr(const FoldingSetNodeIDRef ID,
const SCEV *op, const Type *ty)
: SCEVCastExpr(ID, scSignExtend, op, ty) {
"Cannot sign extend non-integer value!");
}
-void SCEVSignExtendExpr::print(raw_ostream &OS) const {
- OS << "(sext " << *Op->getType() << " " << *Op << " to " << *Ty << ")";
-}
-
-void SCEVCommutativeExpr::print(raw_ostream &OS) const {
- const char *OpStr = getOperationStr();
- OS << "(";
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I) {
- OS << **I;
- if (llvm::next(I) != E)
- OS << OpStr;
- }
- OS << ")";
-}
-
-bool SCEVNAryExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I)
- if (!(*I)->dominates(BB, DT))
- return false;
- return true;
-}
-
-bool SCEVNAryExpr::properlyDominates(BasicBlock *BB, DominatorTree *DT) const {
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I)
- if (!(*I)->properlyDominates(BB, DT))
- return false;
- return true;
-}
-
-bool SCEVNAryExpr::isLoopInvariant(const Loop *L) const {
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I)
- if (!(*I)->isLoopInvariant(L))
- return false;
- return true;
-}
-
-// hasComputableLoopEvolution - N-ary expressions have computable loop
-// evolutions iff they have at least one operand that varies with the loop,
-// but that all varying operands are computable.
-bool SCEVNAryExpr::hasComputableLoopEvolution(const Loop *L) const {
- bool HasVarying = false;
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I) {
- const SCEV *S = *I;
- if (!S->isLoopInvariant(L)) {
- if (S->hasComputableLoopEvolution(L))
- HasVarying = true;
- else
- return false;
- }
- }
- return HasVarying;
-}
-
-bool SCEVNAryExpr::hasOperand(const SCEV *O) const {
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I) {
- const SCEV *S = *I;
- if (O == S || S->hasOperand(O))
- return true;
- }
- return false;
-}
-
-bool SCEVUDivExpr::dominates(BasicBlock *BB, DominatorTree *DT) const {
- return LHS->dominates(BB, DT) && RHS->dominates(BB, DT);
-}
-
-bool SCEVUDivExpr::properlyDominates(BasicBlock *BB, DominatorTree *DT) const {
- return LHS->properlyDominates(BB, DT) && RHS->properlyDominates(BB, DT);
-}
-
-void SCEVUDivExpr::print(raw_ostream &OS) const {
- OS << "(" << *LHS << " /u " << *RHS << ")";
-}
-
-const Type *SCEVUDivExpr::getType() const {
- // In most cases the types of LHS and RHS will be the same, but in some
- // crazy cases one or the other may be a pointer. ScalarEvolution doesn't
- // depend on the type for correctness, but handling types carefully can
- // avoid extra casts in the SCEVExpander. The LHS is more likely to be
- // a pointer type than the RHS, so use the RHS' type here.
- return RHS->getType();
-}
-
-bool SCEVAddRecExpr::isLoopInvariant(const Loop *QueryLoop) const {
- // Add recurrences are never invariant in the function-body (null loop).
- if (!QueryLoop)
- return false;
-
- // This recurrence is variant w.r.t. QueryLoop if QueryLoop contains L.
- if (QueryLoop->contains(L))
- return false;
-
- // This recurrence is invariant w.r.t. QueryLoop if L contains QueryLoop.
- if (L->contains(QueryLoop))
- return true;
-
- // This recurrence is variant w.r.t. QueryLoop if any of its operands
- // are variant.
- for (op_iterator I = op_begin(), E = op_end(); I != E; ++I)
- if (!(*I)->isLoopInvariant(QueryLoop))
- return false;
-
- // Otherwise it's loop-invariant.
- 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 = NumOperands; i != e; ++i)
- OS << ",+," << *Operands[i];
- OS << "}<";
- WriteAsOperand(OS, L->getHeader(), /*PrintType=*/false);
- OS << ">";
-}
-
void SCEVUnknown::deleted() {
- // Clear this SCEVUnknown from ValuesAtScopes.
- SE->ValuesAtScopes.erase(this);
+ // Clear this SCEVUnknown from various maps.
+ SE->forgetMemoizedResults(this);
// Remove this SCEVUnknown from the uniquing map.
SE->UniqueSCEVs.RemoveNode(this);
}
void SCEVUnknown::allUsesReplacedWith(Value *New) {
- // Clear this SCEVUnknown from ValuesAtScopes.
- SE->ValuesAtScopes.erase(this);
+ // Clear this SCEVUnknown from various maps.
+ SE->forgetMemoizedResults(this);
// Remove this SCEVUnknown from the uniquing map.
SE->UniqueSCEVs.RemoveNode(this);
setValPtr(New);
}
-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.
- // Instructions are never considered invariant in the function body
- // (null loop) because they are defined within the "loop".
- if (Instruction *I = dyn_cast<Instruction>(getValue()))
- return L && !L->contains(I);
- return true;
-}
-
-bool SCEVUnknown::dominates(BasicBlock *BB, DominatorTree *DT) const {
- if (Instruction *I = dyn_cast<Instruction>(getValue()))
- return DT->dominates(I->getParent(), BB);
- return true;
-}
-
-bool SCEVUnknown::properlyDominates(BasicBlock *BB, DominatorTree *DT) const {
- if (Instruction *I = dyn_cast<Instruction>(getValue()))
- return DT->properlyDominates(I->getParent(), BB);
- return true;
-}
-
-const Type *SCEVUnknown::getType() const {
- return getValue()->getType();
-}
-
bool SCEVUnknown::isSizeOf(const Type *&AllocTy) const {
if (ConstantExpr *VCE = dyn_cast<ConstantExpr>(getValue()))
if (VCE->getOpcode() == Instruction::PtrToInt)
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, getValue(), false);
-}
-
//===----------------------------------------------------------------------===//
// SCEV Utilities
//===----------------------------------------------------------------------===//
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(AddRecLoop)) {
+ if (isLoopInvariant(Ops[i], AddRecLoop)) {
LIOps.push_back(Ops[i]);
Ops.erase(Ops.begin()+i);
--i; --e;
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(AddRecLoop)) {
+ if (isLoopInvariant(Ops[i], AddRecLoop)) {
LIOps.push_back(Ops[i]);
Ops.erase(Ops.begin()+i);
--i; --e;
for (unsigned i = 1, e = Operands.size(); i != e; ++i)
assert(getEffectiveSCEVType(Operands[i]->getType()) == ETy &&
"SCEVAddRecExpr operand types don't match!");
+ for (unsigned i = 0, e = Operands.size(); i != e; ++i)
+ assert(isLoopInvariant(Operands[i], L) &&
+ "SCEVAddRecExpr operand is not loop-invariant!");
#endif
if (Operands.back()->isZero()) {
// requirement.
bool AllInvariant = true;
for (unsigned i = 0, e = Operands.size(); i != e; ++i)
- if (!Operands[i]->isLoopInvariant(L)) {
+ if (!isLoopInvariant(Operands[i], L)) {
AllInvariant = false;
break;
}
NestedOperands[0] = getAddRecExpr(Operands, L);
AllInvariant = true;
for (unsigned i = 0, e = NestedOperands.size(); i != e; ++i)
- if (!NestedOperands[i]->isLoopInvariant(NestedLoop)) {
+ if (!isLoopInvariant(NestedOperands[i], NestedLoop)) {
AllInvariant = false;
break;
}
ValueExprMapType::iterator It =
ValueExprMap.find(static_cast<Value *>(I));
if (It != ValueExprMap.end()) {
+ const SCEV *Old = It->second;
+
// Short-circuit the def-use traversal if the symbolic name
// ceases to appear in expressions.
- if (It->second != SymName && !It->second->hasOperand(SymName))
+ if (Old != SymName && !hasOperand(Old, SymName))
continue;
// SCEVUnknown for a PHI either means that it has an unrecognized
// 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);
+ !isa<SCEVUnknown>(Old) ||
+ (I != PN && Old == SymName)) {
+ forgetMemoizedResults(Old);
ValueExprMap.erase(It);
}
}
// This is not a valid addrec if the step amount is varying each
// loop iteration, but is not itself an addrec in this loop.
- if (Accum->isLoopInvariant(L) ||
+ if (isLoopInvariant(Accum, L) ||
(isa<SCEVAddRecExpr>(Accum) &&
cast<SCEVAddRecExpr>(Accum)->getLoop() == L)) {
bool HasNUW = false;
// Since the no-wrap flags are on the increment, they apply to the
// post-incremented value as well.
- if (Accum->isLoopInvariant(L))
+ if (isLoopInvariant(Accum, L))
(void)getAddRecExpr(getAddExpr(StartVal, Accum),
Accum, L, HasNUW, HasNSW);
// 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)
+ if (Value *V = SimplifyInstruction(PN, TD, DT))
+ if (LI->replacementPreservesLCSSAForm(PN, V))
return getSCEV(V);
- }
// If it's not a loop phi, we can't handle it yet.
return getUnknown(PN);
///
ConstantRange
ScalarEvolution::getUnsignedRange(const SCEV *S) {
+ // See if we've computed this range already.
+ DenseMap<const SCEV *, ConstantRange>::iterator I = UnsignedRanges.find(S);
+ if (I != UnsignedRanges.end())
+ return I->second;
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
- return ConstantRange(C->getValue()->getValue());
+ return setUnsignedRange(C, ConstantRange(C->getValue()->getValue()));
unsigned BitWidth = getTypeSizeInBits(S->getType());
ConstantRange ConservativeResult(BitWidth, /*isFullSet=*/true);
ConstantRange X = getUnsignedRange(Add->getOperand(0));
for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
X = X.add(getUnsignedRange(Add->getOperand(i)));
- return ConservativeResult.intersectWith(X);
+ return setUnsignedRange(Add, 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 ConservativeResult.intersectWith(X);
+ return setUnsignedRange(Mul, 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 ConservativeResult.intersectWith(X);
+ return setUnsignedRange(SMax, 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 ConservativeResult.intersectWith(X);
+ return setUnsignedRange(UMax, ConservativeResult.intersectWith(X));
}
if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
ConstantRange X = getUnsignedRange(UDiv->getLHS());
ConstantRange Y = getUnsignedRange(UDiv->getRHS());
- return ConservativeResult.intersectWith(X.udiv(Y));
+ return setUnsignedRange(UDiv, ConservativeResult.intersectWith(X.udiv(Y)));
}
if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
ConstantRange X = getUnsignedRange(ZExt->getOperand());
- return ConservativeResult.intersectWith(X.zeroExtend(BitWidth));
+ return setUnsignedRange(ZExt,
+ ConservativeResult.intersectWith(X.zeroExtend(BitWidth)));
}
if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
ConstantRange X = getUnsignedRange(SExt->getOperand());
- return ConservativeResult.intersectWith(X.signExtend(BitWidth));
+ return setUnsignedRange(SExt,
+ ConservativeResult.intersectWith(X.signExtend(BitWidth)));
}
if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
ConstantRange X = getUnsignedRange(Trunc->getOperand());
- return ConservativeResult.intersectWith(X.truncate(BitWidth));
+ return setUnsignedRange(Trunc,
+ ConservativeResult.intersectWith(X.truncate(BitWidth)));
}
if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
ConstantRange ExtEndRange = EndRange.zextOrTrunc(BitWidth*2+1);
if (ExtStartRange.add(ExtMaxBECountRange.multiply(ExtStepRange)) !=
ExtEndRange)
- return ConservativeResult;
+ return setUnsignedRange(AddRec, ConservativeResult);
APInt Min = APIntOps::umin(StartRange.getUnsignedMin(),
EndRange.getUnsignedMin());
APInt Max = APIntOps::umax(StartRange.getUnsignedMax(),
EndRange.getUnsignedMax());
if (Min.isMinValue() && Max.isMaxValue())
- return ConservativeResult;
- return ConservativeResult.intersectWith(ConstantRange(Min, Max+1));
+ return setUnsignedRange(AddRec, ConservativeResult);
+ return setUnsignedRange(AddRec,
+ ConservativeResult.intersectWith(ConstantRange(Min, Max+1)));
}
}
- return ConservativeResult;
+ return setUnsignedRange(AddRec, ConservativeResult);
}
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
ComputeMaskedBits(U->getValue(), Mask, Zeros, Ones, TD);
if (Ones == ~Zeros + 1)
- return ConservativeResult;
- return ConservativeResult.intersectWith(ConstantRange(Ones, ~Zeros + 1));
+ return setUnsignedRange(U, ConservativeResult);
+ return setUnsignedRange(U,
+ ConservativeResult.intersectWith(ConstantRange(Ones, ~Zeros + 1)));
}
- return ConservativeResult;
+ return setUnsignedRange(S, ConservativeResult);
}
/// getSignedRange - Determine the signed range for a particular SCEV.
///
ConstantRange
ScalarEvolution::getSignedRange(const SCEV *S) {
+ DenseMap<const SCEV *, ConstantRange>::iterator I = SignedRanges.find(S);
+ if (I != SignedRanges.end())
+ return I->second;
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(S))
- return ConstantRange(C->getValue()->getValue());
+ return setSignedRange(C, ConstantRange(C->getValue()->getValue()));
unsigned BitWidth = getTypeSizeInBits(S->getType());
ConstantRange ConservativeResult(BitWidth, /*isFullSet=*/true);
ConstantRange X = getSignedRange(Add->getOperand(0));
for (unsigned i = 1, e = Add->getNumOperands(); i != e; ++i)
X = X.add(getSignedRange(Add->getOperand(i)));
- return ConservativeResult.intersectWith(X);
+ return setSignedRange(Add, 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 ConservativeResult.intersectWith(X);
+ return setSignedRange(Mul, 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 ConservativeResult.intersectWith(X);
+ return setSignedRange(SMax, 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 ConservativeResult.intersectWith(X);
+ return setSignedRange(UMax, ConservativeResult.intersectWith(X));
}
if (const SCEVUDivExpr *UDiv = dyn_cast<SCEVUDivExpr>(S)) {
ConstantRange X = getSignedRange(UDiv->getLHS());
ConstantRange Y = getSignedRange(UDiv->getRHS());
- return ConservativeResult.intersectWith(X.udiv(Y));
+ return setSignedRange(UDiv, ConservativeResult.intersectWith(X.udiv(Y)));
}
if (const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(S)) {
ConstantRange X = getSignedRange(ZExt->getOperand());
- return ConservativeResult.intersectWith(X.zeroExtend(BitWidth));
+ return setSignedRange(ZExt,
+ ConservativeResult.intersectWith(X.zeroExtend(BitWidth)));
}
if (const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(S)) {
ConstantRange X = getSignedRange(SExt->getOperand());
- return ConservativeResult.intersectWith(X.signExtend(BitWidth));
+ return setSignedRange(SExt,
+ ConservativeResult.intersectWith(X.signExtend(BitWidth)));
}
if (const SCEVTruncateExpr *Trunc = dyn_cast<SCEVTruncateExpr>(S)) {
ConstantRange X = getSignedRange(Trunc->getOperand());
- return ConservativeResult.intersectWith(X.truncate(BitWidth));
+ return setSignedRange(Trunc,
+ ConservativeResult.intersectWith(X.truncate(BitWidth)));
}
if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(S)) {
ConstantRange ExtEndRange = EndRange.sextOrTrunc(BitWidth*2+1);
if (ExtStartRange.add(ExtMaxBECountRange.multiply(ExtStepRange)) !=
ExtEndRange)
- return ConservativeResult;
+ return setSignedRange(AddRec, ConservativeResult);
APInt Min = APIntOps::smin(StartRange.getSignedMin(),
EndRange.getSignedMin());
APInt Max = APIntOps::smax(StartRange.getSignedMax(),
EndRange.getSignedMax());
if (Min.isMinSignedValue() && Max.isMaxSignedValue())
- return ConservativeResult;
- return ConservativeResult.intersectWith(ConstantRange(Min, Max+1));
+ return setSignedRange(AddRec, ConservativeResult);
+ return setSignedRange(AddRec,
+ ConservativeResult.intersectWith(ConstantRange(Min, Max+1)));
}
}
- return ConservativeResult;
+ return setSignedRange(AddRec, ConservativeResult);
}
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
// For a SCEVUnknown, ask ValueTracking.
if (!U->getValue()->getType()->isIntegerTy() && !TD)
- return ConservativeResult;
+ return setSignedRange(U, ConservativeResult);
unsigned NS = ComputeNumSignBits(U->getValue(), TD);
if (NS == 1)
- return ConservativeResult;
- return ConservativeResult.intersectWith(
+ return setSignedRange(U, ConservativeResult);
+ return setSignedRange(U, ConservativeResult.intersectWith(
ConstantRange(APInt::getSignedMinValue(BitWidth).ashr(NS - 1),
- APInt::getSignedMaxValue(BitWidth).ashr(NS - 1)+1));
+ APInt::getSignedMaxValue(BitWidth).ashr(NS - 1)+1)));
}
- return ConservativeResult;
+ return setSignedRange(S, ConservativeResult);
}
/// createSCEV - We know that there is no SCEV for the specified value.
// If C is a single bit, it may be in the sign-bit position
// before the zero-extend. In this case, represent the xor
// using an add, which is equivalent, and re-apply the zext.
- APInt Trunc = APInt(CI->getValue()).trunc(Z0TySize);
- if (APInt(Trunc).zext(getTypeSizeInBits(UTy)) == CI->getValue() &&
+ APInt Trunc = CI->getValue().trunc(Z0TySize);
+ if (Trunc.zext(getTypeSizeInBits(UTy)) == CI->getValue() &&
Trunc.isSignBit())
return getZeroExtendExpr(getAddExpr(Z0, getConstant(Trunc)),
UTy);
if (Pair.second) {
BackedgeTakenInfo BECount = ComputeBackedgeTakenCount(L);
if (BECount.Exact != getCouldNotCompute()) {
- assert(BECount.Exact->isLoopInvariant(L) &&
- BECount.Max->isLoopInvariant(L) &&
+ assert(isLoopInvariant(BECount.Exact, L) &&
+ isLoopInvariant(BECount.Max, L) &&
"Computed backedge-taken count isn't loop invariant for loop!");
++NumTripCountsComputed;
ValueExprMapType::iterator It =
ValueExprMap.find(static_cast<Value *>(I));
if (It != ValueExprMap.end()) {
+ const SCEV *Old = It->second;
+
// 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)) {
- ValuesAtScopes.erase(It->second);
+ if (!isa<PHINode>(I) || !isa<SCEVUnknown>(Old)) {
+ forgetMemoizedResults(Old);
ValueExprMap.erase(It);
}
if (PHINode *PN = dyn_cast<PHINode>(I))
ValueExprMapType::iterator It = ValueExprMap.find(static_cast<Value *>(I));
if (It != ValueExprMap.end()) {
- ValuesAtScopes.erase(It->second);
+ forgetMemoizedResults(It->second);
ValueExprMap.erase(It);
if (PHINode *PN = dyn_cast<PHINode>(I))
ConstantEvolutionLoopExitValue.erase(PN);
ValueExprMapType::iterator It = ValueExprMap.find(static_cast<Value *>(I));
if (It != ValueExprMap.end()) {
- ValuesAtScopes.erase(It->second);
+ forgetMemoizedResults(It->second);
ValueExprMap.erase(It);
if (PHINode *PN = dyn_cast<PHINode>(I))
ConstantEvolutionLoopExitValue.erase(PN);
// At this point, we would like to compute how many iterations of the
// loop the predicate will return true for these inputs.
- if (LHS->isLoopInvariant(L) && !RHS->isLoopInvariant(L)) {
+ if (isLoopInvariant(LHS, L) && !isLoopInvariant(RHS, L)) {
// If there is a loop-invariant, force it into the RHS.
std::swap(LHS, RHS);
Cond = ICmpInst::getSwappedPredicate(Cond);
// We can only recognize very limited forms of loop index expressions, in
// particular, only affine AddRec's like {C1,+,C2}.
const SCEVAddRecExpr *IdxExpr = dyn_cast<SCEVAddRecExpr>(Idx);
- if (!IdxExpr || !IdxExpr->isAffine() || IdxExpr->isLoopInvariant(L) ||
+ if (!IdxExpr || !IdxExpr->isAffine() || isLoopInvariant(IdxExpr, L) ||
!isa<SCEVConstant>(IdxExpr->getOperand(0)) ||
!isa<SCEVConstant>(IdxExpr->getOperand(1)))
return getCouldNotCompute();
// bit width during computations.
APInt AD = A.lshr(Mult2).zext(BW + 1); // AD = A / D
APInt Mod(BW + 1, 0);
- Mod.set(BW - Mult2); // Mod = N / D
+ Mod.setBit(BW - Mult2); // Mod = N / D
APInt I = AD.multiplicativeInverse(Mod);
// 4. Compute the minimum unsigned root of the equation:
// 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)) {
+ if (isLoopInvariant(LHS, L) && properlyDominates(LHS, L->getHeader())) {
std::swap(LHS, RHS);
Pred = ICmpInst::getSwappedPredicate(Pred);
Changed = true;
trivially_true:
// Return 0 == 0.
- LHS = RHS = getConstant(Type::getInt1Ty(getContext()), 0);
+ LHS = RHS = getConstant(ConstantInt::getFalse(getContext()));
Pred = ICmpInst::ICMP_EQ;
return true;
trivially_false:
// Return 0 != 0.
- LHS = RHS = getConstant(Type::getInt1Ty(getContext()), 0);
+ LHS = RHS = getConstant(ConstantInt::getFalse(getContext()));
Pred = ICmpInst::ICMP_NE;
return true;
}
ScalarEvolution::HowManyLessThans(const SCEV *LHS, const SCEV *RHS,
const Loop *L, bool isSigned) {
// Only handle: "ADDREC < LoopInvariant".
- if (!RHS->isLoopInvariant(L)) return getCouldNotCompute();
+ if (!isLoopInvariant(RHS, L)) return getCouldNotCompute();
const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(LHS);
if (!AddRec || AddRec->getLoop() != L)
BackedgeTakenCounts.clear();
ConstantEvolutionLoopExitValue.clear();
ValuesAtScopes.clear();
+ LoopDispositions.clear();
+ BlockDispositions.clear();
+ UnsignedRanges.clear();
+ SignedRanges.clear();
UniqueSCEVs.clear();
SCEVAllocator.Reset();
}
if (L) {
OS << "\t\t" "Exits: ";
const SCEV *ExitValue = SE.getSCEVAtScope(SV, L->getParentLoop());
- if (!ExitValue->isLoopInvariant(L)) {
+ if (!SE.isLoopInvariant(ExitValue, L)) {
OS << "<<Unknown>>";
} else {
OS << *ExitValue;
PrintLoopInfo(OS, &SE, *I);
}
+ScalarEvolution::LoopDisposition
+ScalarEvolution::getLoopDisposition(const SCEV *S, const Loop *L) {
+ std::map<const Loop *, LoopDisposition> &Values = LoopDispositions[S];
+ std::pair<std::map<const Loop *, LoopDisposition>::iterator, bool> Pair =
+ Values.insert(std::make_pair(L, LoopVariant));
+ if (!Pair.second)
+ return Pair.first->second;
+
+ LoopDisposition D = computeLoopDisposition(S, L);
+ return LoopDispositions[S][L] = D;
+}
+
+ScalarEvolution::LoopDisposition
+ScalarEvolution::computeLoopDisposition(const SCEV *S, const Loop *L) {
+ switch (S->getSCEVType()) {
+ case scConstant:
+ return LoopInvariant;
+ case scTruncate:
+ case scZeroExtend:
+ case scSignExtend:
+ return getLoopDisposition(cast<SCEVCastExpr>(S)->getOperand(), L);
+ case scAddRecExpr: {
+ const SCEVAddRecExpr *AR = cast<SCEVAddRecExpr>(S);
+
+ // If L is the addrec's loop, it's computable.
+ if (AR->getLoop() == L)
+ return LoopComputable;
+
+ // Add recurrences are never invariant in the function-body (null loop).
+ if (!L)
+ return LoopVariant;
+
+ // This recurrence is variant w.r.t. L if L contains AR's loop.
+ if (L->contains(AR->getLoop()))
+ return LoopVariant;
+
+ // This recurrence is invariant w.r.t. L if AR's loop contains L.
+ if (AR->getLoop()->contains(L))
+ return LoopInvariant;
+
+ // This recurrence is variant w.r.t. L if any of its operands
+ // are variant.
+ for (SCEVAddRecExpr::op_iterator I = AR->op_begin(), E = AR->op_end();
+ I != E; ++I)
+ if (!isLoopInvariant(*I, L))
+ return LoopVariant;
+
+ // Otherwise it's loop-invariant.
+ return LoopInvariant;
+ }
+ case scAddExpr:
+ case scMulExpr:
+ case scUMaxExpr:
+ case scSMaxExpr: {
+ const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(S);
+ bool HasVarying = false;
+ for (SCEVNAryExpr::op_iterator I = NAry->op_begin(), E = NAry->op_end();
+ I != E; ++I) {
+ LoopDisposition D = getLoopDisposition(*I, L);
+ if (D == LoopVariant)
+ return LoopVariant;
+ if (D == LoopComputable)
+ HasVarying = true;
+ }
+ return HasVarying ? LoopComputable : LoopInvariant;
+ }
+ case scUDivExpr: {
+ const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S);
+ LoopDisposition LD = getLoopDisposition(UDiv->getLHS(), L);
+ if (LD == LoopVariant)
+ return LoopVariant;
+ LoopDisposition RD = getLoopDisposition(UDiv->getRHS(), L);
+ if (RD == LoopVariant)
+ return LoopVariant;
+ return (LD == LoopInvariant && RD == LoopInvariant) ?
+ LoopInvariant : LoopComputable;
+ }
+ case scUnknown:
+ // All non-instruction values are loop invariant. All instructions are loop
+ // invariant if they are not contained in the specified loop.
+ // Instructions are never considered invariant in the function body
+ // (null loop) because they are defined within the "loop".
+ if (Instruction *I = dyn_cast<Instruction>(cast<SCEVUnknown>(S)->getValue()))
+ return (L && !L->contains(I)) ? LoopInvariant : LoopVariant;
+ return LoopInvariant;
+ case scCouldNotCompute:
+ llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
+ return LoopVariant;
+ default: break;
+ }
+ llvm_unreachable("Unknown SCEV kind!");
+ return LoopVariant;
+}
+
+bool ScalarEvolution::isLoopInvariant(const SCEV *S, const Loop *L) {
+ return getLoopDisposition(S, L) == LoopInvariant;
+}
+
+bool ScalarEvolution::hasComputableLoopEvolution(const SCEV *S, const Loop *L) {
+ return getLoopDisposition(S, L) == LoopComputable;
+}
+
+ScalarEvolution::BlockDisposition
+ScalarEvolution::getBlockDisposition(const SCEV *S, const BasicBlock *BB) {
+ std::map<const BasicBlock *, BlockDisposition> &Values = BlockDispositions[S];
+ std::pair<std::map<const BasicBlock *, BlockDisposition>::iterator, bool>
+ Pair = Values.insert(std::make_pair(BB, DoesNotDominateBlock));
+ if (!Pair.second)
+ return Pair.first->second;
+
+ BlockDisposition D = computeBlockDisposition(S, BB);
+ return BlockDispositions[S][BB] = D;
+}
+
+ScalarEvolution::BlockDisposition
+ScalarEvolution::computeBlockDisposition(const SCEV *S, const BasicBlock *BB) {
+ switch (S->getSCEVType()) {
+ case scConstant:
+ return ProperlyDominatesBlock;
+ case scTruncate:
+ case scZeroExtend:
+ case scSignExtend:
+ return getBlockDisposition(cast<SCEVCastExpr>(S)->getOperand(), BB);
+ case scAddRecExpr: {
+ // This uses a "dominates" query instead of "properly dominates" query
+ // to test for proper dominance too, because the instruction which
+ // produces the addrec's value is a PHI, and a PHI effectively properly
+ // dominates its entire containing block.
+ const SCEVAddRecExpr *AR = cast<SCEVAddRecExpr>(S);
+ if (!DT->dominates(AR->getLoop()->getHeader(), BB))
+ return DoesNotDominateBlock;
+ }
+ // FALL THROUGH into SCEVNAryExpr handling.
+ case scAddExpr:
+ case scMulExpr:
+ case scUMaxExpr:
+ case scSMaxExpr: {
+ const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(S);
+ bool Proper = true;
+ for (SCEVNAryExpr::op_iterator I = NAry->op_begin(), E = NAry->op_end();
+ I != E; ++I) {
+ BlockDisposition D = getBlockDisposition(*I, BB);
+ if (D == DoesNotDominateBlock)
+ return DoesNotDominateBlock;
+ if (D == DominatesBlock)
+ Proper = false;
+ }
+ return Proper ? ProperlyDominatesBlock : DominatesBlock;
+ }
+ case scUDivExpr: {
+ const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S);
+ const SCEV *LHS = UDiv->getLHS(), *RHS = UDiv->getRHS();
+ BlockDisposition LD = getBlockDisposition(LHS, BB);
+ if (LD == DoesNotDominateBlock)
+ return DoesNotDominateBlock;
+ BlockDisposition RD = getBlockDisposition(RHS, BB);
+ if (RD == DoesNotDominateBlock)
+ return DoesNotDominateBlock;
+ return (LD == ProperlyDominatesBlock && RD == ProperlyDominatesBlock) ?
+ ProperlyDominatesBlock : DominatesBlock;
+ }
+ case scUnknown:
+ if (Instruction *I =
+ dyn_cast<Instruction>(cast<SCEVUnknown>(S)->getValue())) {
+ if (I->getParent() == BB)
+ return DominatesBlock;
+ if (DT->properlyDominates(I->getParent(), BB))
+ return ProperlyDominatesBlock;
+ return DoesNotDominateBlock;
+ }
+ return ProperlyDominatesBlock;
+ case scCouldNotCompute:
+ llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
+ return DoesNotDominateBlock;
+ default: break;
+ }
+ llvm_unreachable("Unknown SCEV kind!");
+ return DoesNotDominateBlock;
+}
+
+bool ScalarEvolution::dominates(const SCEV *S, const BasicBlock *BB) {
+ return getBlockDisposition(S, BB) >= DominatesBlock;
+}
+
+bool ScalarEvolution::properlyDominates(const SCEV *S, const BasicBlock *BB) {
+ return getBlockDisposition(S, BB) == ProperlyDominatesBlock;
+}
+
+bool ScalarEvolution::hasOperand(const SCEV *S, const SCEV *Op) const {
+ switch (S->getSCEVType()) {
+ case scConstant:
+ return false;
+ case scTruncate:
+ case scZeroExtend:
+ case scSignExtend: {
+ const SCEVCastExpr *Cast = cast<SCEVCastExpr>(S);
+ const SCEV *CastOp = Cast->getOperand();
+ return Op == CastOp || hasOperand(CastOp, Op);
+ }
+ case scAddRecExpr:
+ case scAddExpr:
+ case scMulExpr:
+ case scUMaxExpr:
+ case scSMaxExpr: {
+ const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(S);
+ for (SCEVNAryExpr::op_iterator I = NAry->op_begin(), E = NAry->op_end();
+ I != E; ++I) {
+ const SCEV *NAryOp = *I;
+ if (NAryOp == Op || hasOperand(NAryOp, Op))
+ return true;
+ }
+ return false;
+ }
+ case scUDivExpr: {
+ const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S);
+ const SCEV *LHS = UDiv->getLHS(), *RHS = UDiv->getRHS();
+ return LHS == Op || hasOperand(LHS, Op) ||
+ RHS == Op || hasOperand(RHS, Op);
+ }
+ case scUnknown:
+ return false;
+ case scCouldNotCompute:
+ llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
+ return false;
+ default: break;
+ }
+ llvm_unreachable("Unknown SCEV kind!");
+ return false;
+}
+
+void ScalarEvolution::forgetMemoizedResults(const SCEV *S) {
+ ValuesAtScopes.erase(S);
+ LoopDispositions.erase(S);
+ BlockDispositions.erase(S);
+ UnsignedRanges.erase(S);
+ SignedRanges.erase(S);
+}