[llvm] [CGData] OutlinedHashTree (PR #89792)

[Kyungwoo Lee via llvm-commits]

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@@ -0,0 +1,106 @@
+//===-- OutlinedHashTree.cpp ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// An OutlinedHashTree is a Trie that contains sequences of stable hash values
+// of instructions that have been outlined. This OutlinedHashTree can be used
+// to understand the outlined instruction sequences collected across modules.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGenData/OutlinedHashTree.h"
+
+#include <stack>
+#include <tuple>
+
+#define DEBUG_TYPE "outlined-hash-tree"
+
+using namespace llvm;
+
+void OutlinedHashTree::walkGraph(EdgeCallbackFn CallbackEdge,
+                                 NodeCallbackFn CallbackNode) const {
+  std::stack<const HashNode *> Stack;
+  Stack.push(getRoot());
+
+  while (!Stack.empty()) {
+    const auto *Current = Stack.top();
+    Stack.pop();
+    CallbackNode(Current);
+
+    // Sorted walk for the stable output.
+    std::map<stable_hash, const HashNode *> SortedSuccessors;
+    for (const auto &P : Current->Successors)
+      SortedSuccessors[P.first] = P.second.get();
+
+    for (const auto &P : SortedSuccessors) {
+      CallbackEdge(Current, P.second);
+      Stack.push(P.second);
+    }
+  }
+}
+
+void OutlinedHashTree::insert(const HashSequencePair &SequencePair) {
+  const auto &Sequence = SequencePair.first;
+  unsigned Count = SequencePair.second;
+
+  HashNode *Current = getRoot();
+  for (stable_hash StableHash : Sequence) {
+    auto I = Current->Successors.find(StableHash);
+    if (I == Current->Successors.end()) {
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kyulee-com wrote:

The same answer below. We used `std::make_unique` for `HashNode` in this `OutlinedHashTree`.

https://github.com/llvm/llvm-project/pull/89792