Introduce memoization for ScalarEvolution dominates and properlyDominates
queries, and SCEVExpander getRelevantLoop queries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119595 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index d9eb8c1..b7c110f 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -608,15 +608,22 @@
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)) {
@@ -625,16 +632,22 @@
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))
- 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);
+ 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;
+ }
llvm_unreachable("Unexpected SCEV type!");
+ return 0;
}
namespace {
@@ -682,8 +695,7 @@
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.
@@ -752,8 +764,7 @@
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));