TypeTree add fast path for checkedOrIn

enzyme/Enzyme/TypeAnalysis/TypeTree.h

@@ -1239,8 +1239,26 @@ class TypeTree : public std::enable_shared_from_this<TypeTree> {
  /// changed Setting `PointerIntSame` considers pointers and integers as
  /// equivalent If this is an illegal operation, `LegalOr` will be set to false
  bool checkedOrIn(const TypeTree &RHS, bool PointerIntSame, bool &LegalOr) {
- // TODO detect recursive merge and simplify
+ // Add fast path where nothing could change because all potentially inserted
+ // value are already in the map
+ {
+ bool newval = false;
+ for (const auto &pair : RHS.mapping) {
+ auto found = mapping.find(pair.first);
+ if (found == mapping.end()) {
+ newval = true;
+ break;
+ }
+ if (found->second != pair.second) {
+ newval = true;
+ break;
+ }
+ }
+ if (!newval)
+ return false;
+ }
 
+ // TODO detect recursive merge and simplify
  bool changed = false;
  for (auto &pair : RHS.mapping) {
  changed |= checkedOrIn(pair.first, pair.second, PointerIntSame, LegalOr);