return A; // Arbitrarily break the tie.
}
-/// GetRelevantLoop - Get the most relevant loop associated with the given
+/// getRelevantLoop - Get the most relevant loop associated with the given
/// expression, according to PickMostRelevantLoop.
-static const Loop *GetRelevantLoop(const SCEV *S, LoopInfo &LI,
- DominatorTree &DT) {
+const Loop *SCEVExpander::getRelevantLoop(const SCEV *S) {
+ // Test whether we've already computed the most relevant loop for this SCEV.
+ std::pair<DenseMap<const SCEV *, const Loop *>::iterator, bool> Pair =
+ RelevantLoops.insert(std::make_pair(S, static_cast<const Loop *>(0)));
+ if (!Pair.second)
+ return Pair.first->second;
+
if (isa<SCEVConstant>(S))
+ // A constant has no relevant loops.
return 0;
if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
if (const Instruction *I = dyn_cast<Instruction>(U->getValue()))
- return LI.getLoopFor(I->getParent());
+ return Pair.first->second = SE.LI->getLoopFor(I->getParent());
+ // A non-instruction has no relevant loops.
return 0;
}
if (const SCEVNAryExpr *N = dyn_cast<SCEVNAryExpr>(S)) {
L = AR->getLoop();
for (SCEVNAryExpr::op_iterator I = N->op_begin(), E = N->op_end();
I != E; ++I)
- L = PickMostRelevantLoop(L, GetRelevantLoop(*I, LI, DT), DT);
- return L;
+ L = PickMostRelevantLoop(L, getRelevantLoop(*I), *SE.DT);
+ return RelevantLoops[N] = L;
+ }
+ if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S)) {
+ const Loop *Result = getRelevantLoop(C->getOperand());
+ return RelevantLoops[C] = Result;
+ }
+ if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S)) {
+ const Loop *Result =
+ PickMostRelevantLoop(getRelevantLoop(D->getLHS()),
+ getRelevantLoop(D->getRHS()),
+ *SE.DT);
+ return RelevantLoops[D] = Result;
}
- if (const SCEVCastExpr *C = dyn_cast<SCEVCastExpr>(S))
- return GetRelevantLoop(C->getOperand(), LI, DT);
- if (const SCEVUDivExpr *D = dyn_cast<SCEVUDivExpr>(S))
- return PickMostRelevantLoop(GetRelevantLoop(D->getLHS(), LI, DT),
- GetRelevantLoop(D->getRHS(), LI, DT),
- DT);
llvm_unreachable("Unexpected SCEV type!");
+ return 0;
}
namespace {
SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops;
for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()),
E(S->op_begin()); I != E; ++I)
- OpsAndLoops.push_back(std::make_pair(GetRelevantLoop(*I, *SE.LI, *SE.DT),
- *I));
+ OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I));
// Sort by loop. Use a stable sort so that constants follow non-constants and
// pointer operands precede non-pointer operands.
SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops;
for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()),
E(S->op_begin()); I != E; ++I)
- OpsAndLoops.push_back(std::make_pair(GetRelevantLoop(*I, *SE.LI, *SE.DT),
- *I));
+ OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I));
// Sort by loop. Use a stable sort so that constants follow non-constants.
std::stable_sort(OpsAndLoops.begin(), OpsAndLoops.end(), LoopCompare(*SE.DT));
// Strip off any non-loop-dominating component from the addrec start.
const SCEV *Start = Normalized->getStart();
const SCEV *PostLoopOffset = 0;
- if (!Start->properlyDominates(L->getHeader(), SE.DT)) {
+ if (!SE.properlyDominates(Start, L->getHeader())) {
PostLoopOffset = Start;
Start = SE.getConstant(Normalized->getType(), 0);
Normalized =
// Strip off any non-loop-dominating component from the addrec step.
const SCEV *Step = Normalized->getStepRecurrence(SE);
const SCEV *PostLoopScale = 0;
- if (!Step->dominates(L->getHeader(), SE.DT)) {
+ if (!SE.dominates(Step, L->getHeader())) {
PostLoopScale = Step;
Step = SE.getConstant(Normalized->getType(), 1);
Normalized =
SE.getUnknown(expand(Rest))));
}
- // {0,+,1} --> Insert a canonical induction variable into the loop!
- if (S->isAffine() && S->getOperand(1)->isOne()) {
- // If there's a canonical IV, just use it.
- if (CanonicalIV) {
- assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) &&
- "IVs with types different from the canonical IV should "
- "already have been handled!");
- return CanonicalIV;
- }
-
+ // If we don't yet have a canonical IV, create one.
+ if (!CanonicalIV) {
// Create and insert the PHI node for the induction variable in the
// specified loop.
BasicBlock *Header = L->getHeader();
- PHINode *PN = PHINode::Create(Ty, "indvar", Header->begin());
- rememberInstruction(PN);
+ CanonicalIV = PHINode::Create(Ty, "indvar", Header->begin());
+ rememberInstruction(CanonicalIV);
Constant *One = ConstantInt::get(Ty, 1);
for (pred_iterator HPI = pred_begin(Header), HPE = pred_end(Header);
if (L->contains(HP)) {
// Insert a unit add instruction right before the terminator
// corresponding to the back-edge.
- Instruction *Add = BinaryOperator::CreateAdd(PN, One, "indvar.next",
- HP->getTerminator());
+ Instruction *Add = BinaryOperator::CreateAdd(CanonicalIV, One,
+ "indvar.next",
+ HP->getTerminator());
rememberInstruction(Add);
- PN->addIncoming(Add, HP);
+ CanonicalIV->addIncoming(Add, HP);
} else {
- PN->addIncoming(Constant::getNullValue(Ty), HP);
+ CanonicalIV->addIncoming(Constant::getNullValue(Ty), HP);
}
}
}
+ // {0,+,1} --> Insert a canonical induction variable into the loop!
+ if (S->isAffine() && S->getOperand(1)->isOne()) {
+ assert(Ty == SE.getEffectiveSCEVType(CanonicalIV->getType()) &&
+ "IVs with types different from the canonical IV should "
+ "already have been handled!");
+ return CanonicalIV;
+ }
+
// {0,+,F} --> {0,+,1} * F
- // Get the canonical induction variable I for this loop.
- Value *I = CanonicalIV ?
- CanonicalIV :
- getOrInsertCanonicalInductionVariable(L, Ty);
// If this is a simple linear addrec, emit it now as a special case.
if (S->isAffine()) // {0,+,F} --> i*F
return
expand(SE.getTruncateOrNoop(
- SE.getMulExpr(SE.getUnknown(I),
+ SE.getMulExpr(SE.getUnknown(CanonicalIV),
SE.getNoopOrAnyExtend(S->getOperand(1),
- I->getType())),
+ CanonicalIV->getType())),
Ty));
// If this is a chain of recurrences, turn it into a closed form, using the
// folders, then expandCodeFor the closed form. This allows the folders to
// simplify the expression without having to build a bunch of special code
// into this folder.
- const SCEV *IH = SE.getUnknown(I); // Get I as a "symbolic" SCEV.
+ const SCEV *IH = SE.getUnknown(CanonicalIV); // Get I as a "symbolic" SCEV.
// Promote S up to the canonical IV type, if the cast is foldable.
const SCEV *NewS = S;
- const SCEV *Ext = SE.getNoopOrAnyExtend(S, I->getType());
+ const SCEV *Ext = SE.getNoopOrAnyExtend(S, CanonicalIV->getType());
if (isa<SCEVAddRecExpr>(Ext))
NewS = Ext;
Instruction *InsertPt = Builder.GetInsertPoint();
for (Loop *L = SE.LI->getLoopFor(Builder.GetInsertBlock()); ;
L = L->getParentLoop())
- if (S->isLoopInvariant(L)) {
+ if (SE.isLoopInvariant(S, L)) {
if (!L) break;
if (BasicBlock *Preheader = L->getLoopPreheader())
InsertPt = Preheader->getTerminator();
// If the SCEV is computable at this level, insert it into the header
// after the PHIs (and after any other instructions that we've inserted
// there) so that it is guaranteed to dominate any user inside the loop.
- if (L && S->hasComputableLoopEvolution(L) && !PostIncLoops.count(L))
+ if (L && SE.hasComputableLoopEvolution(S, L) && !PostIncLoops.count(L))
InsertPt = L->getHeader()->getFirstNonPHI();
while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt))
InsertPt = llvm::next(BasicBlock::iterator(InsertPt));
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