nicolas/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[LCG] Remove the use of the parent sets to compute connectivity when

Browse Source 
merging RefSCCs.

The logic to directly use the reference edges is simpler and not
substantially slower (despite the comments to the contrary) because this
is not actually an especially hot part of LCG in practice.

llvm-svn: 310161
This commit is contained in:
Chandler Carruth
2017-08-05 03:37:37 +00:00
parent a3c3d7b442
commit 13ffd110ad
1 changed files with 14 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
llvm/lib/Analysis/LazyCallGraph.cpp
View File

@@ -957,22 +957,20 @@ LazyCallGraph::RefSCC::insertIncomingRefEdge(Node &SourceN, Node &TargetN) {
// RefSCCs (and their edges) are visited here.
auto ComputeSourceConnectedSet = [&](SmallPtrSetImpl<RefSCC *> &Set) {
Set.insert(&SourceC);
SmallVector<RefSCC *, 4> Worklist;
Worklist.push_back(&SourceC);
do {
RefSCC &RC = *Worklist.pop_back_val();
for (RefSCC &ParentRC : RC.parents()) {
// Skip any RefSCCs outside the range of source to target in the
// postorder sequence.
int ParentIdx = G->getRefSCCIndex(ParentRC);
assert(ParentIdx > SourceIdx && "Parent cannot precede source in postorder!");
if (ParentIdx > TargetIdx)
continue;
if (Set.insert(&ParentRC).second)
// First edge connecting to this parent, add it to our worklist.
Worklist.push_back(&ParentRC);
}
} while (!Worklist.empty());
auto IsConnected = [&](RefSCC &RC) {
for (SCC &C : RC)
for (Node &N : C)
for (Edge &E : *N)
if (Set.count(G->lookupRefSCC(E.getNode())))
return true;
return false;
};
for (RefSCC *C : make_range(G->PostOrderRefSCCs.begin() + SourceIdx + 1,
G->PostOrderRefSCCs.begin() + TargetIdx + 1))
if (IsConnected(*C))
Set.insert(C);
};
// Use a normal worklist to find which SCCs the target connects to. We still