text: /*===================== begin_copyright_notice ==================================
  
  Copyright (c) 2017 Intel Corporation
  
  Permission is hereby granted, free of charge, to any person obtaining a
  copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:
  
  The above copyright notice and this permission notice shall be included
  in all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  
  ======================= end_copyright_notice ==================================*/
  #pragma once
  
  #include "common/LLVMWarningsPush.hpp"
  #include <llvm/Pass.h>
  #include <llvm/IR/Function.h>
  #include "common/LLVMWarningsPop.hpp"
  
  namespace IGC
  {
  
      class CodeGenContextWrapper;
      class WIAnalysis;
      class FastValueMapBase;
  
      class TranslationTable : public llvm::FunctionPass
      {
      public:
          static char ID;
  
          TranslationTable();
  
          void RegisterListener(FastValueMapBase* fvmb)
          {
              m_ValueMaps.push_back(fvmb);
          }
  
          void getAnalysisUsage(llvm::AnalysisUsage& AU) const override {
              AU.setPreservesAll();
          }
  
          bool runOnFunction(llvm::Function& F) override;
          bool run(llvm::Function& F);
  
          llvm::StringRef getPassName() const override {
              return "TranslationTable";
          }
  
          unsigned int GetNumIDs() const { return m_NumIDS; }
  
          void RegisterNewValueAndAssignID(llvm::Value* val);
  
      private:
  
          unsigned int m_NumIDS;
          llvm::SmallVector<FastValueMapBase*, 8> m_ValueMaps;
  
      }; //class TranslationTable
  
  
      //Since we are mapping Value pointers to attribute, to avoid confusion
      //we will not call this as 'key to value' mapping but 'value to attribute' mapping
  
      //Each mapped attribute type should provide an implementation of this template
      //specialization.
      template<typename T>
      struct FastValueMapAttributeInfo {
          //no default implementation
      };
  
      // Provide FastValueMapAttributeInfo for unsigned ints.
      template<> struct FastValueMapAttributeInfo<unsigned> {
          static inline unsigned getEmptyAttribute() { return ~0U; }
      };
  
      //===----------------------------------------------------------------------===//
      class FastValueMapBase
      {
      public:
          FastValueMapBase() : m_pTT(nullptr)
          {
          }
  
          FastValueMapBase(TranslationTable* table) : m_pTT(table)
          {
          }
  
          //This have to be virtual, since only a concrete class knows the exact
          //type of the attribute which is to be initialized.
          virtual void Update() = 0;
  
      public:
          TranslationTable* m_pTT;
      };
  
      //===----------------------------------------------------------------------===//
      template<typename A, typename T, typename AttributeInfoT = FastValueMapAttributeInfo<T> >
      class FastValueMapImpl : public FastValueMapBase
      {
          //No default implementation.
      };
  
      //===----------------------------------------------------------------------===//
      //Let us use llvm::DenseMap as a type selector for this specialization.
      template<typename T, typename AttributeInfoT>
      class FastValueMapImpl<llvm::DenseMap<const llvm::Value*, T>, T, AttributeInfoT> : public FastValueMapBase
      {
      public:
  
          FastValueMapImpl(TranslationTable* table) : FastValueMapBase(table)
          {
              Initialize(table);
          }
  
          FastValueMapImpl()
          {
          }
  
          void Initialize(const TranslationTable* table)
          {
              //DenseMap should be kept at less than 75% of its capacity.
              unsigned int preferredSize = (unsigned int)(table->GetNumIDs() * 1.4); //be little bit conservative
  
              //Add some more space for growing.
              preferredSize = (unsigned int)(preferredSize * 1.1);
  
              m_attributeMap.reserve(preferredSize);
          }
  
          T GetAttributeWithoutCreating(const llvm::Value* val) const
          {
              typename llvm::DenseMap<const llvm::Value*, T>::const_iterator it;
              it = m_attributeMap.find(val);
              if (it != m_attributeMap.end())
              {
                  return (*it).second;
              }
  
              return AttributeInfoT::getEmptyAttribute();
          }
  
          void SetAttribute(const llvm::Value* val, T attr)
          {
              m_attributeMap[val] = attr;
          }
  
  
          void Update() override
          {
              //TODO: what do we do? Should we re-size?
          }
  
          T end() const
          {
              return AttributeInfoT::getEmptyAttribute();
          }
  
          void clear()
          {
              //TODO: need to think more about this scenario
              m_attributeMap.clear();
          }
      private:
          llvm::DenseMap<const llvm::Value*, T> m_attributeMap;
      };
  
      template<typename T, typename AttributeInfoT>
      class FastValueMap : public FastValueMapImpl<llvm::DenseMap<const llvm::Value*, T>, T, AttributeInfoT>
      {
  
      };
  
  } //namespace IGC
  