/*===================== 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/InstVisitor.h>
#include <llvm/IR/DataLayout.h>
#include "common/LLVMWarningsPop.hpp"

#include <vector>
#include <map>

namespace IGC
{
    /// @brief  PrivateMemoryBufferAnalysis pass used for analyzing private memory alloca instructions
    ///         and determining the size and offset of each buffer and the total amount of private memory
    ///          needed by each work item. This is done by analyzing the alloca instructions.

    class PrivateMemoryBufferAnalysis : public llvm::ModulePass, public llvm::InstVisitor<PrivateMemoryBufferAnalysis>
    {
    public:
        // Pass identification, replacement for typeid
        static char ID;

        /// @brief  Constructor
        PrivateMemoryBufferAnalysis();

        /// @brief  Destructor
        ~PrivateMemoryBufferAnalysis() { }

        /// @brief  Provides name of pass
        virtual llvm::StringRef getPassName() const override
        {
            return "PrivateMemoryBufferAnalysis";
        }

        virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override
        {
            AU.setPreservesAll();
        }

        /// @brief  Process module
        /// @param  M The module to process
        bool runOnModule(llvm::Module &M) override;

        /// @brief  Alloca instructions visitor.
        ///         Checks for private memory allocation, determins the size and offset of each allocation, 
        ///         helps calculate the total amount of private memory needed by each wotk item.
        /// @param  AI The alloca instruction.
        void visitAllocaInst(llvm::AllocaInst &AI);

        /// @brief  get offset of alloca instruction in private memory buffer for given function.
        /// @param  pFunc The function conatins the alloca.
        /// @param  pAI The alloca instruction.
        /// @return offset in private buffer of given alloca instruction.
        unsigned int getBufferOffset(llvm::Function* pFunc, llvm::AllocaInst* pAI)
        {
            assert(m_privateInfoMap.count(pFunc) && "Function should have private buffer info");
            assert(m_privateInfoMap[pFunc].m_bufferOffsets.count(pAI) && "AllocalInst should have buffer offset info");
            return m_privateInfoMap[pFunc].m_bufferOffsets[pAI];
        }

        /// @brief  get offset of alloca instruction in private memory buffer for given function.
        /// @param  pFunc The function conatins the alloca.
        /// @param  pAI The alloca instruction.
        /// @return buffer size of given alloca instruction.
        unsigned int getBufferSize(llvm::Function* pFunc, llvm::AllocaInst* pAI)
        {
            assert(m_privateInfoMap.count(pFunc) && "Function should have private buffer info");
            assert(m_privateInfoMap[pFunc].m_bufferSizes.count(pAI) && "AllocalInst should have buffer size info");
            return m_privateInfoMap[pFunc].m_bufferSizes[pAI];
        }

        /// @brief  get alloca instructions to handle of given function.
        /// @param  pFunc The function.
        /// @return alloca instructions of given function.
        std::vector<llvm::AllocaInst*> &getAllocaInsts(llvm::Function* pFunc)
        {
            assert(m_privateInfoMap.count(pFunc) && "Function should have private buffer info");
            return m_privateInfoMap[pFunc].m_allocaInsts;
        }

        /// @brief  get total private memory buffer size per WI of given function.
        /// @param  pFunc The function.
        /// @return total private memory buffer size of given function.
        unsigned int getTotalPrivateMemPerWI(llvm::Function* pFunc)
        {
            assert(m_privateInfoMap.count(pFunc) && "Function should have private buffer info");
            return m_privateInfoMap[pFunc].m_bufferTotalSize;
        }

    private:
        /// @brief  Finds all alloca instructions, analyzes them, determins the size and offset of each
        ///         private buffer.
        /// @param  F The destination function.
        void runOnFunction(llvm::Function &F);

    private:

        /// @brief  The data layout
        const llvm::DataLayout* m_DL;

        /// @brief  Used for calculating the total amount of private memory size per thread
        unsigned int m_currentOffset;

        /// @brief  The max alignment needed by an alloca instruction in this function
        ///         Used for calculating the alignment of the private memory buffer size
        unsigned int m_maxAlignment;

        typedef struct {
            /// @brief - Total amount of private memory size per thread
            unsigned int m_bufferTotalSize;

            /// @brief - Collected alloca instruction for processing
            std::vector<llvm::AllocaInst*> m_allocaInsts;

            /// @brief - map between alloca instruction and offset in buffer
            std::map<llvm::AllocaInst*, unsigned int> m_bufferOffsets;

            /// @brief - map between alloca instruction and total size
            std::map<llvm::AllocaInst*, unsigned int> m_bufferSizes;
        } PrivateBufferPerFuncInfo;
        
        /// @brief - map between function and total private buffer size
        std::map<llvm::Function*, PrivateBufferPerFuncInfo> m_privateInfoMap;
    };

} // namespace IGC
