WIP: DO-NOT-MERGE: NCE experiments: Initial LRU

src/core/arm/nce/lru_cache.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <list>
+#include <unordered_map>
+
+template<typename KeyType, typename ValueType>
+class LRUCache {
+public:
+    explicit LRUCache(size_t capacity) : capacity(capacity) {}
+
+    ValueType* get(const KeyType& key) {
+        auto it = cache_map.find(key);
+        if (it == cache_map.end()) {
+            return nullptr;
+        }
+
+        // Move the accessed item to the front of the list (most recently used)
+        cache_list.splice(cache_list.begin(), cache_list, it->second.first);
+        return &(it->second.second);
+    }
+
+    void put(const KeyType& key, const ValueType& value) {
+        auto it = cache_map.find(key);
+
+        if (it != cache_map.end()) {
+            // Key exists, update value and move to front
+            it->second.second = value;
+            cache_list.splice(cache_list.begin(), cache_list, it->second.first);
+            return;
+        }
+
+        // Remove the least recently used item if cache is full
+        if (cache_map.size() >= capacity) {
+            auto last = cache_list.back();
+            cache_map.erase(last);
+            cache_list.pop_back();
+        }
+
+        // Insert new item at the front
+        cache_list.push_front(key);
+        cache_map[key] = {cache_list.begin(), value};
+    }
+
+    void clear() {
+        cache_map.clear();
+        cache_list.clear();
+    }
+
+    size_t size() const {
+        return cache_map.size();
+    }
+
+private:
+    size_t capacity;
+    std::list<KeyType> cache_list;
+    std::unordered_map<KeyType, std::pair<typename std::list<KeyType>::iterator, ValueType>> cache_map;
+};