Speed up cycle checking significantly by caching results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96956 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 33899a4..ef21a15 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6315,7 +6315,11 @@
}
static void checkForCyclesHelper(const SDNode *N,
- std::set<const SDNode *> &visited) {
+ std::set<const SDNode *> &visited,
+ std::set<const SDNode *> &checked) {
+ if (checked.find(N) != checked.end())
+ return;
+
if (visited.find(N) != visited.end()) {
dbgs() << "Offending node:\n";
N->dumprFull();
@@ -6329,16 +6333,18 @@
assert(inserted && "Missed cycle");
for(unsigned i = 0; i < N->getNumOperands(); ++i) {
- checkForCyclesHelper(N->getOperand(i).getNode(), visited);
+ checkForCyclesHelper(N->getOperand(i).getNode(), visited, checked);
}
visited.erase(i);
+ checked.insert(N);
}
void llvm::checkForCycles(const llvm::SDNode *N) {
#ifdef XDEBUG
assert(N && "Checking nonexistant SDNode");
std::set<const SDNode *> visited;
- checkForCyclesHelper(N, visited);
+ std::set<const SDNode *> checked;
+ checkForCyclesHelper(N, visited, checked);
#endif
}