MemoryCache.hpp

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//===-- MemoryCache.hpp -- In-memory code cache header implementation --===//
//
// Part of the Proteus 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
//
//===----------------------------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
 
#ifndef PROTEUS_JITCACHE_HPP
#define PROTEUS_JITCACHE_HPP
 
#include <cstdint>
#include <iostream>
 
#include <llvm/ADT/StringRef.h>
 
#include "proteus/Hashing.hpp"
#include "proteus/TimeTracing.hpp"
#include "proteus/Utils.h"
 
namespace proteus {
 
using namespace llvm;
 
template <typename Function_t> class MemoryCache {
public:
  MemoryCache(const std::string &Label)
      : Label(Label), DistributedRank(getDistributedRank()) {}
  Function_t lookup(HashT &HashValue) {
    TIMESCOPE("lookup");
    Accesses++;
 
    auto It = CacheMap.find(HashValue);
    if (It == CacheMap.end())
      return nullptr;
 
    It->second.NumExecs++;
    It->second.NumHits++;
    Hits++;
    return It->second.FunctionPtr;
  }
 
  void insert(HashT &HashValue, Function_t FunctionPtr, StringRef FnName) {
    if (Config::get().ProteusDebugOutput) {
      if (CacheMap.count(HashValue))
        PROTEUS_FATAL_ERROR("MemoryCache collision detected");
    }
 
    auto &CacheEntry = CacheMap[HashValue];
    CacheEntry.FunctionPtr = FunctionPtr;
    CacheEntry.NumExecs = 1;
    CacheEntry.NumHits = 0;
 
    if (Config::get().ProteusDebugOutput) {
      CacheEntry.FnName = FnName.str();
    }
  }
 
  void printStats() {
    printf("[proteus][%s] MemoryCache rank %s hits %lu accesses %lu\n",
           Label.c_str(), DistributedRank.c_str(), Hits, Accesses);
    for (const auto &[HashValue, JCE] : CacheMap) {
      std::cout << "[proteus][" << Label << "] MemoryCache rank "
                << DistributedRank << " HashValue " << HashValue.toString()
                << " NumExecs " << JCE.NumExecs << " NumHits " << JCE.NumHits;
      if (Config::get().ProteusDebugOutput) {
        printf(" FnName %s", JCE.FnName.c_str());
      }
      printf("\n");
    }
  }
 
private:
  struct MemoryCacheEntry {
    Function_t FunctionPtr;
    uint64_t NumExecs;
    uint64_t NumHits;
    std::string FnName;
  };
 
  std::unordered_map<HashT, MemoryCacheEntry> CacheMap;
  uint64_t Hits = 0;
  uint64_t Accesses = 0;
  const std::string Label;
  const std::string DistributedRank;
};
 
} // namespace proteus
 
#endif