}
for (Value *Op : C->operand_values())
- if (Visited.insert(cast<Constant>(Op)))
+ if (Visited.insert(cast<Constant>(Op)).second)
Worklist.push_back(cast<Constant>(Op));
}
}
for (Instruction &I : BB)
for (Value *Op : I.operand_values())
if (Constant *C = dyn_cast<Constant>(Op))
- if (Visited.insert(C))
+ if (Visited.insert(C).second)
Worklist.push_back(C);
// We've collected all the constant (and thus potentially function or
findCallees(Worklist, Visited, Callees, CalleeIndexMap);
}
+void LazyCallGraph::Node::insertEdgeInternal(Function &Callee) {
+ if (Node *N = G->lookup(Callee))
+ return insertEdgeInternal(*N);
+
+ CalleeIndexMap.insert(std::make_pair(&Callee, Callees.size()));
+ Callees.push_back(&Callee);
+}
+
+void LazyCallGraph::Node::insertEdgeInternal(Node &CalleeN) {
+ CalleeIndexMap.insert(std::make_pair(&CalleeN.getFunction(), Callees.size()));
+ Callees.push_back(&CalleeN);
+}
+
void LazyCallGraph::Node::removeEdgeInternal(Function &Callee) {
auto IndexMapI = CalleeIndexMap.find(&Callee);
assert(IndexMapI != CalleeIndexMap.end() &&
"Callee not in the callee set for this caller?");
- Callees.erase(Callees.begin() + IndexMapI->second);
+ Callees[IndexMapI->second] = nullptr;
CalleeIndexMap.erase(IndexMapI);
}
SmallPtrSet<Constant *, 16> Visited;
for (GlobalVariable &GV : M.globals())
if (GV.hasInitializer())
- if (Visited.insert(GV.getInitializer()))
+ if (Visited.insert(GV.getInitializer()).second)
Worklist.push_back(GV.getInitializer());
DEBUG(dbgs() << " Adding functions referenced by global initializers to the "
"entry set.\n");
findCallees(Worklist, Visited, EntryNodes, EntryIndexMap);
- for (auto &Entry : EntryNodes)
+ for (auto &Entry : EntryNodes) {
+ assert(!Entry.isNull() &&
+ "We can't have removed edges before we finish the constructor!");
if (Function *F = Entry.dyn_cast<Function *>())
SCCEntryNodes.push_back(F);
else
SCCEntryNodes.push_back(&Entry.get<Node *>()->getFunction());
+ }
}
LazyCallGraph::LazyCallGraph(LazyCallGraph &&G)
G->SCCMap[&N] = this;
}
+bool LazyCallGraph::SCC::isDescendantOf(const SCC &C) const {
+ // Walk up the parents of this SCC and verify that we eventually find C.
+ SmallVector<const SCC *, 4> AncestorWorklist;
+ AncestorWorklist.push_back(this);
+ do {
+ const SCC *AncestorC = AncestorWorklist.pop_back_val();
+ if (AncestorC->isChildOf(C))
+ return true;
+ for (const SCC *ParentC : AncestorC->ParentSCCs)
+ AncestorWorklist.push_back(ParentC);
+ } while (!AncestorWorklist.empty());
+
+ return false;
+}
+
+void LazyCallGraph::SCC::insertIntraSCCEdge(Node &CallerN, Node &CalleeN) {
+ // First insert it into the caller.
+ CallerN.insertEdgeInternal(CalleeN);
+
+ assert(G->SCCMap.lookup(&CallerN) == this && "Caller must be in this SCC.");
+ assert(G->SCCMap.lookup(&CalleeN) == this && "Callee must be in this SCC.");
+
+ // Nothing changes about this SCC or any other.
+}
+
+void LazyCallGraph::SCC::insertOutgoingEdge(Node &CallerN, Node &CalleeN) {
+ // First insert it into the caller.
+ CallerN.insertEdgeInternal(CalleeN);
+
+ assert(G->SCCMap.lookup(&CallerN) == this && "Caller must be in this SCC.");
+
+ SCC &CalleeC = *G->SCCMap.lookup(&CalleeN);
+ assert(&CalleeC != this && "Callee must not be in this SCC.");
+ assert(CalleeC.isDescendantOf(*this) &&
+ "Callee must be a descendant of the Caller.");
+
+ // The only change required is to add this SCC to the parent set of the
+ // callee.
+ CalleeC.ParentSCCs.insert(this);
+}
+
+SmallVector<LazyCallGraph::SCC *, 1>
+LazyCallGraph::SCC::insertIncomingEdge(Node &CallerN, Node &CalleeN) {
+ // First insert it into the caller.
+ CallerN.insertEdgeInternal(CalleeN);
+
+ assert(G->SCCMap.lookup(&CalleeN) == this && "Callee must be in this SCC.");
+
+ SCC &CallerC = *G->SCCMap.lookup(&CallerN);
+ assert(&CallerC != this && "Caller must not be in this SCC.");
+ assert(CallerC.isDescendantOf(*this) &&
+ "Caller must be a descendant of the Callee.");
+
+ // The algorithm we use for merging SCCs based on the cycle introduced here
+ // is to walk the SCC inverted DAG formed by the parent SCC sets. The inverse
+ // graph has the same cycle properties as the actual DAG of the SCCs, and
+ // when forming SCCs lazily by a DFS, the bottom of the graph won't exist in
+ // many cases which should prune the search space.
+ //
+ // FIXME: We can get this pruning behavior even after the incremental SCC
+ // formation by leaving behind (conservative) DFS numberings in the nodes,
+ // and pruning the search with them. These would need to be cleverly updated
+ // during the removal of intra-SCC edges, but could be preserved
+ // conservatively.
+
+ // The set of SCCs that are connected to the caller, and thus will
+ // participate in the merged connected component.
+ SmallPtrSet<SCC *, 8> ConnectedSCCs;
+ ConnectedSCCs.insert(this);
+ ConnectedSCCs.insert(&CallerC);
+
+ // We build up a DFS stack of the parents chains.
+ SmallVector<std::pair<SCC *, SCC::parent_iterator>, 8> DFSSCCs;
+ SmallPtrSet<SCC *, 8> VisitedSCCs;
+ int ConnectedDepth = -1;
+ SCC *C = this;
+ parent_iterator I = parent_begin(), E = parent_end();
+ for (;;) {
+ while (I != E) {
+ SCC &ParentSCC = *I++;
+
+ // If we have already processed this parent SCC, skip it, and remember
+ // whether it was connected so we don't have to check the rest of the
+ // stack. This also handles when we reach a child of the 'this' SCC (the
+ // callee) which terminates the search.
+ if (ConnectedSCCs.count(&ParentSCC)) {
+ ConnectedDepth = std::max<int>(ConnectedDepth, DFSSCCs.size());
+ continue;
+ }
+ if (VisitedSCCs.count(&ParentSCC))
+ continue;
+
+ // We fully explore the depth-first space, adding nodes to the connected
+ // set only as we pop them off, so "recurse" by rotating to the parent.
+ DFSSCCs.push_back(std::make_pair(C, I));
+ C = &ParentSCC;
+ I = ParentSCC.parent_begin();
+ E = ParentSCC.parent_end();
+ }
+
+ // If we've found a connection anywhere below this point on the stack (and
+ // thus up the parent graph from the caller), the current node needs to be
+ // added to the connected set now that we've processed all of its parents.
+ if ((int)DFSSCCs.size() == ConnectedDepth) {
+ --ConnectedDepth; // We're finished with this connection.
+ ConnectedSCCs.insert(C);
+ } else {
+ // Otherwise remember that its parents don't ever connect.
+ assert(ConnectedDepth < (int)DFSSCCs.size() &&
+ "Cannot have a connected depth greater than the DFS depth!");
+ VisitedSCCs.insert(C);
+ }
+
+ if (DFSSCCs.empty())
+ break; // We've walked all the parents of the caller transitively.
+
+ // Pop off the prior node and position to unwind the depth first recursion.
+ std::tie(C, I) = DFSSCCs.pop_back_val();
+ E = C->parent_end();
+ }
+
+ // Now that we have identified all of the SCCs which need to be merged into
+ // a connected set with the inserted edge, merge all of them into this SCC.
+ // FIXME: This operation currently creates ordering stability problems
+ // because we don't use stably ordered containers for the parent SCCs or the
+ // connected SCCs.
+ unsigned NewNodeBeginIdx = Nodes.size();
+ for (SCC *C : ConnectedSCCs) {
+ if (C == this)
+ continue;
+ for (SCC *ParentC : C->ParentSCCs)
+ if (!ConnectedSCCs.count(ParentC))
+ ParentSCCs.insert(ParentC);
+ C->ParentSCCs.clear();
+
+ for (Node *N : *C) {
+ for (Node &ChildN : *N) {
+ SCC &ChildC = *G->SCCMap.lookup(&ChildN);
+ if (&ChildC != C)
+ ChildC.ParentSCCs.erase(C);
+ }
+ G->SCCMap[N] = this;
+ Nodes.push_back(N);
+ }
+ C->Nodes.clear();
+ }
+ for (auto I = Nodes.begin() + NewNodeBeginIdx, E = Nodes.end(); I != E; ++I)
+ for (Node &ChildN : **I) {
+ SCC &ChildC = *G->SCCMap.lookup(&ChildN);
+ if (&ChildC != this)
+ ChildC.ParentSCCs.insert(this);
+ }
+
+ // We return the list of SCCs which were merged so that callers can
+ // invalidate any data they have associated with those SCCs. Note that these
+ // SCCs are no longer in an interesting state (they are totally empty) but
+ // the pointers will remain stable for the life of the graph itself.
+ return SmallVector<SCC *, 1>(ConnectedSCCs.begin(), ConnectedSCCs.end());
+}
+
void LazyCallGraph::SCC::removeInterSCCEdge(Node &CallerN, Node &CalleeN) {
// First remove it from the node.
CallerN.removeEdgeInternal(CalleeN.getFunction());
continue;
}
- // Track the lowest link of the childen, if any are still in the stack.
+ // Track the lowest link of the children, if any are still in the stack.
// Any child not on the stack will have a LowLink of -1.
assert(ChildN.LowLink != 0 &&
"Low-link must not be zero with a non-zero DFS number.");
}
SmallVector<LazyCallGraph::SCC *, 1>
-LazyCallGraph::SCC::removeIntraSCCEdge(Node &CallerN,
- Node &CalleeN) {
+LazyCallGraph::SCC::removeIntraSCCEdge(Node &CallerN, Node &CalleeN) {
// First remove it from the node.
CallerN.removeEdgeInternal(CalleeN.getFunction());
- // We return a list of the resulting SCCs, where 'this' is always the first
- // element.
+ // We return a list of the resulting *new* SCCs in postorder.
SmallVector<SCC *, 1> ResultSCCs;
- ResultSCCs.push_back(this);
// Direct recursion doesn't impact the SCC graph at all.
if (&CallerN == &CalleeN)
}
}
#ifndef NDEBUG
- if (ResultSCCs.size() > 1)
+ if (!ResultSCCs.empty())
assert(!IsLeafSCC && "This SCC cannot be a leaf as we have split out new "
"SCCs by removing this edge.");
if (!std::any_of(G->LeafSCCs.begin(), G->LeafSCCs.end(),
#endif
// If this SCC stopped being a leaf through this edge removal, remove it from
// the leaf SCC list.
- if (!IsLeafSCC && ResultSCCs.size() > 1)
+ if (!IsLeafSCC && !ResultSCCs.empty())
G->LeafSCCs.erase(std::remove(G->LeafSCCs.begin(), G->LeafSCCs.end(), this),
- G->LeafSCCs.end());
+ G->LeafSCCs.end());
// Return the new list of SCCs.
return ResultSCCs;
}
+void LazyCallGraph::insertEdge(Node &CallerN, Function &Callee) {
+ assert(SCCMap.empty() && DFSStack.empty() &&
+ "This method cannot be called after SCCs have been formed!");
+
+ return CallerN.insertEdgeInternal(Callee);
+}
+
void LazyCallGraph::removeEdge(Node &CallerN, Function &Callee) {
assert(SCCMap.empty() && DFSStack.empty() &&
"This method cannot be called after SCCs have been formed!");
Node *N = Worklist.pop_back_val();
N->G = this;
for (auto &Callee : N->Callees)
- if (Node *CalleeN = Callee.dyn_cast<Node *>())
- Worklist.push_back(CalleeN);
+ if (!Callee.isNull())
+ if (Node *CalleeN = Callee.dyn_cast<Node *>())
+ Worklist.push_back(CalleeN);
}
}
bool IsLeafSCC = true;
for (Node *SCCN : NewSCC->Nodes)
for (Node &SCCChildN : *SCCN) {
- if (SCCMap.lookup(&SCCChildN) == NewSCC)
- continue;
SCC &ChildSCC = *SCCMap.lookup(&SCCChildN);
+ if (&ChildSCC == NewSCC)
+ continue;
ChildSCC.ParentSCCs.insert(NewSCC);
IsLeafSCC = false;
}
continue;
}
- // Track the lowest link of the childen, if any are still in the stack.
+ // Track the lowest link of the children, if any are still in the stack.
assert(ChildN.LowLink != 0 &&
"Low-link must not be zero with a non-zero DFS number.");
if (ChildN.LowLink >= 0 && ChildN.LowLink < N->LowLink)
SmallPtrSetImpl<LazyCallGraph::Node *> &Printed) {
// Recurse depth first through the nodes.
for (LazyCallGraph::Node &ChildN : N)
- if (Printed.insert(&ChildN))
+ if (Printed.insert(&ChildN).second)
printNodes(OS, ChildN, Printed);
OS << " Call edges in function: " << N.getFunction().getName() << "\n";
OS << "\n";
}
-PreservedAnalyses LazyCallGraphPrinterPass::run(Module *M,
+PreservedAnalyses LazyCallGraphPrinterPass::run(Module &M,
ModuleAnalysisManager *AM) {
LazyCallGraph &G = AM->getResult<LazyCallGraphAnalysis>(M);
- OS << "Printing the call graph for module: " << M->getModuleIdentifier()
+ OS << "Printing the call graph for module: " << M.getModuleIdentifier()
<< "\n\n";
SmallPtrSet<LazyCallGraph::Node *, 16> Printed;
for (LazyCallGraph::Node &N : G)
- if (Printed.insert(&N))
+ if (Printed.insert(&N).second)
printNodes(OS, N, Printed);
for (LazyCallGraph::SCC &SCC : G.postorder_sccs())
printSCC(OS, SCC);
return PreservedAnalyses::all();
-
}
projects / oota-llvm.git / blobdiff