[NFC] Improve DeduplicateExecutables bucketing

Use the result types as a part of the hash when grouping ops. This
vastly improves the performance of this pass when there are several
similar objects that have different types.

This pass can become very slow because checking structural equivalence is a
costly procedure pass is O(n^2) with respect to the bucket size.

Signed-off-by: Ian Wood <ianwood2024@u.northwestern.edu>

Author: IanWood1

compiler/src/iree/compiler/Dialect/Flow/Transforms/DeduplicateExecutables.cpp

@@ -87,13 +87,16 @@ static int deduplicateObjects(Operation *scopeOp,
   // 5 was randomly chosen to be small enough to not increase overhead much,
   // but giving at least enough of a sample that there is some bucketing. This
   // was not empirically determined.
+  constexpr int kMaxHashedOps = 5;
   llvm::MapVector<uint32_t, SmallVector<SymbolOpInterface>> objectMap;
   for (auto objectOp : allObjectOps) {
     int count = 0;
     llvm::hash_code hash(1);
     objectOp->walk([&](Operation *it) {
       hash = llvm::hash_combine(hash, it->getName());
-      return (++count >= 5) ? WalkResult::interrupt() : WalkResult::advance();
+      hash = llvm::hash_combine(hash, it->getResultTypes());
+      return (++count >= kMaxHashedOps) ? WalkResult::interrupt()
+                                        : WalkResult::advance();
     });
     objectMap[hash_value(hash)].push_back(cast<SymbolOpInterface>(objectOp));
   }