/*===================== 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 "Compiler/CISACodeGen/WIAnalysis.hpp"
#include "Compiler/CISACodeGen/PatternMatchPass.hpp"
#include "Compiler/MetaDataUtilsWrapper.h"
#include "Compiler/CISACodeGen/PayloadMapping.hpp"
#include "common/LLVMWarningsPush.hpp"
#include <llvm/Pass.h>
#include <llvm/ADT/DenseSet.h>
#include <llvm/IR/InstVisitor.h>
#include <llvm/IR/Dominators.h>
#include <llvm/Support/Debug.h>
#include <llvm/Support/Allocator.h>
#include "common/LLVMWarningsPop.hpp"
#include "GenISAIntrinsics/GenIntrinsicInst.h"
#include "Probe/Assertion.h"

namespace IGC {

    class CEncoder;
    class CVariable;
    class CodeGenContextWrapper;
    class DeSSA;


    class CoalescingEngine : public llvm::FunctionPass, public llvm::InstVisitor<CoalescingEngine>
    {
        //TODO: this is fixed for now, but once we have pressure heuristic, could be relaxed
        static const int MaxTupleSize = 12;

    public:
        static char ID; // Pass identification, replacement for typeid
        CoalescingEngine();

        virtual void getAnalysisUsage(llvm::AnalysisUsage& AU) const override;

        virtual void releaseMemory() override {
            Allocator.Reset();

            for (auto itr = m_CCTupleList.begin(),
                iend = m_CCTupleList.end();
                itr != iend; ++itr)
            {
                CCTuple* ccTuple = *itr;
                delete ccTuple;
            }
            m_CCTupleList.clear();
            //Nodes need not be deallocated since they are
            //owned by bump allocator (Allocator), and are destroyed
            //once bump allocator goes out the the scope.
            NodeCCTupleMap.clear();
            ValueNodeMap.clear();
            BBProcessingDefs.clear();
            NodeOffsetMap.clear();
        }

        bool runOnFunction(llvm::Function&) override;

        virtual llvm::StringRef getPassName() const override {
            return "CoalescingEngine";
        }

        /// print - print partitions in human readable form
        void print(llvm::raw_ostream& OS, const llvm::Module* = 0) const override;

        /// dump - Dump the partitions to dbgs().
        void dump() const;

        void ProcessBlock(llvm::BasicBlock* bb);

        //
        bool MatchSingleInstruction(llvm::GenIntrinsicInst* I);


        int GetSingleElementWidth(
            SIMDMode simdMode,
            const llvm::DataLayout* pDL,
            llvm::Value* val)
        {
            int result = 0;
            int mult = 1;
            if (val->getType()->isHalfTy() && simdMode == SIMDMode::SIMD8)
            {
                mult = 2;
            }

            result = int_cast<int>(mult *
                numLanes(simdMode) *
                pDL->getTypeAllocSize(val->getType()));

            return result;
        }

        //
        CVariable* PrepareExplicitPayload(
            CShader* outProgram,
            CEncoder* encoder,
            SIMDMode simdMode,
            const llvm::DataLayout* pDL,
            llvm::Instruction* inst,
            int& payloadOffset);


        void visitCastInst(llvm::CastInst& I);
        void visitBinaryOperator(llvm::BinaryOperator& I);
        void visitCmpInst(llvm::CmpInst& I);
        void visitPHINode(llvm::PHINode& I);
        void visitUnaryInstruction(llvm::UnaryInstruction& I);
        void visitCallInst(llvm::CallInst& I);
        void visitSelectInst(llvm::SelectInst& I);
        void visitBitCastInst(llvm::BitCastInst& I);
        void visitInstruction(llvm::Instruction& I);
        void visitLoadInst(llvm::LoadInst& I);
        void visitStoreInst(llvm::StoreInst& I);


        //////////////////////////////////////////////////////////////////////////
        struct ElementNode
        {
            enum Flags {
                kRegisterIsolatedFlag = 1,
                kPHIIsolatedFlag = 2
            };
            ElementNode(llvm::Value* _value) :
                value(_value), rank(0)
            {
                parent.setPointer(this);
            }

            ~ElementNode()
            {
            }

            ElementNode* getLeader();

            // Fields:
            llvm::PointerIntPair<ElementNode*, 2> parent;
            llvm::Value* value;
            unsigned rank;
        };

        //////////////////////////////////////////////////////////////////////////
        struct CCTuple
        {
            CCTuple() :
                leftBound(0),
                rightBound(0),
                hasNonHomogeneousElements(false),
                rootInst(nullptr)
            {
            }

            int leftBound;
            int rightBound;


            int GetLeftBound() const
            {
                return leftBound;
            }

            int GetRightBound() const
            {
                return rightBound;
            }


            //cannot be safely extended left/right (used for non-homogeneous payload modeling)
            bool hasNonHomogeneousElements;

            llvm::Instruction* rootInst;

            inline bool HasNonHomogeneousElements() const
            {
                return hasNonHomogeneousElements;
            }

            inline void SetHasNonHomogeneousElements(llvm::Instruction* _rootInst)
            {
                IGC_ASSERT(rootInst == nullptr);
                rootInst = _rootInst;
                hasNonHomogeneousElements = true;
            }

            inline llvm::Instruction* GetRoot() const
            {
                return rootInst;
            }


            inline uint GetNumElements() const
            {
                IGC_ASSERT(rightBound >= leftBound);
                return rightBound - leftBound + 1;
            }

            inline void InitializeIndexWithCCRoot(int index, ElementNode* elNode)
            {
                OffsetToCCMap[index] = elNode;

                ResizeBounds(index);
            }

            inline void ResizeBounds(int index)
            {
                if (index < leftBound)
                {
                    leftBound = index;
                }

                if (index > rightBound)
                {
                    rightBound = index;
                }
            }

            inline void CheckIndexForNonInitializedSlot(int index)
            {
                //if (OffsetToCCMap.count(index) == 0)
                {
                    ResizeBounds(index);
                }
            }


            ElementNode* GetCCNodeWithIndex(int index)
            {
                return OffsetToCCMap[index];
            }

            void AttachNodeAtIndex(int index, ElementNode* node, CoalescingEngine& CE)
            {
                if (OffsetToCCMap.count(index) == 0 || OffsetToCCMap[index] == NULL)
                {
                    IGC_ASSERT(node->value == CE.getRegRoot(node->value));

                    CE.NodeCCTupleMap[node] = this;
                    CE.NodeOffsetMap[node] = index;

                    InitializeIndexWithCCRoot(index, node);
                    CE.CurrentDominatingParent[node->value] = node->value;
                    CE.ImmediateDominatingParent[node->value] = NULL;
                }
                else
                {
                    if (OffsetToCCMap[index] == node)
                    {
                        //Do nothing, it is already there.
                    }
                    else
                    {
                        //Here comes a logic that will attach a new node to CC.
                        IGC_ASSERT(OffsetToCCMap.count(index));
                        IGC_ASSERT(OffsetToCCMap[index]);

                        llvm::Value* ccRootValue = OffsetToCCMap[index]->value;

                        CE.unionRegs(ccRootValue, node->value);

                        llvm::Value* NewParent = CE.GetActualDominatingParent(
                            ccRootValue,
                            llvm::dyn_cast<llvm::Instruction>(node->value));

                        CE.ImmediateDominatingParent[node->value] = NewParent;
                        CE.CurrentDominatingParent[ccRootValue] = node->value;
                    }
                }
            }

            //print in human readable form
            void print(llvm::raw_ostream& OS, const llvm::Module* = 0) const;

            void dump() const;

            //FIXME: not sure whether this is the best choice
        protected:
            llvm::DenseMap<int, ElementNode*> OffsetToCCMap;

            friend class CoalescingEngine;
        };

        friend struct CCTuple;

        ///returns non-null CCtuple pointer if there is at least
        // one value that is 'coalesced' into the tuple.
        // It returns one of those values (e.g. for type insepction)
        // if the condition is true.
        CCTuple* IsAnyValueCoalescedInCCTuple(
            llvm::Instruction* inst,
            const uint numOperands,
            int& zeroBasedPayloadElementOffset,
            llvm::Value*& val);

        ///
        bool IsPayloadCovered(
            llvm::Instruction* inst,
            CCTuple* ccTuple,
            const uint numOperands,
            const int payloadToCCTupleRelativeOffset);


        //FIXME: do a filter over relevant (TGI) instructions
        uint DetermineWeight(llvm::Value* val)
        {
            if (ValueWeightMap.count(val)) {
                return ValueWeightMap[val];
            }
            else {
                uint numUsers = 0;
                {
                    llvm::SmallPtrSet<llvm::User*, 8> touchedUsers;
                    for (llvm::Value::user_iterator i = val->user_begin(), e = val->user_end(); i != e; ++i) {
                        llvm::User* user = *i;
                        if (llvm::isa<llvm::Instruction>(user)) {
                            if (!touchedUsers.count(user))
                            {
                                numUsers++;
                                touchedUsers.insert(user);
                            }
                        }
                    }
                }
                ValueWeightMap[val] = numUsers;
                return numUsers;
            }
        }

        //FIXME: this might not be the most effective way if called multiple times
        bool IsolationFilter(llvm::Value* val) const
        {
            if (isCoalescedByDeSSA(val)) {
                return true;
            }
            if (llvm::dyn_cast<llvm::PHINode>(val)) {
                return true;
            }
            else if (llvm::dyn_cast<llvm::ExtractElementInst>(val)) {
                return true;
            }
            else {
                for (llvm::Value::user_iterator i = val->user_begin(), e = val->user_end(); i != e; ++i)
                {
                    if (llvm::dyn_cast<llvm::PHINode>(*i)) {
                        return true;
                    }
                }
            }

            return false;
        }

        bool IsValIsolated(llvm::Value* val)
        {
            return IsolationFilter(val) ||
                isUniform(val) ||
                llvm::isa<llvm::Argument>(val);
        }

        inline bool IsValConstOrIsolated(llvm::Value* val) const
        {
            return llvm::isa<llvm::Constant>(val) ||
                IsolationFilter(val) ||
                isUniform(val) ||
                llvm::isa<llvm::Argument>(val);
        }


        void IncrementalCoalesce(llvm::BasicBlock*);
        void PrepareTuple(
            const uint numOperands,
            llvm::Instruction* tupleGeneratingInstruction,
            llvm::SmallPtrSet<CCTuple*, 8> & touchedTuplesSet,
            llvm::SmallVector<CCTuple*, 8> & touchedTuples,
            bool& isAnyNodeAnchored,
            bool& isAnyNodeCoalescable);

        void DecideSplit(llvm::Instruction* tupleGeneratingInstruction);

        void CreateTuple(
            const uint numOperands,
            llvm::Instruction* tupleGeneratingInstruction);

        void DetermineAnchor(
            const uint numOperands,
            const llvm::Instruction* tupleGeneratingInstruction,
            CCTuple*& ccTuple,
            int& rootTupleStartOffset,
            int& thisTupleStartOffset);

        //Return true if it is ok to continue, false if interference is detected
        bool EvictOrStop(
            CCTuple* ccTuple,
            const int index,
            llvm::Instruction* tupleGeneratingInstruction,
            bool const forceEviction,
            //out:
            bool& interferes)
        {
            if (!IsInsertionSlotAvailable(ccTuple, index, tupleGeneratingInstruction)) {
                if (forceEviction) {
                    PrepareInsertionSlot(ccTuple, index, tupleGeneratingInstruction);
                    return true; //we can continue
                }
                else {
                    interferes = true;
                    return false; //abort whole 'transaction'
                }
            }
            return true;
        }

        class ProcessInterferencesElementFunctor;

        bool InterferenceCheck(
            const uint numOperands,
            llvm::Instruction* tupleGeneratingInstruction,
            const int offsetDiff,
            CCTuple* ccTuple,
            //out:
            ProcessInterferencesElementFunctor* interferencesFunctor);

        /// \brief return true if element slot is safe for copying-in
        /// canExtend - if true, it is assumed that ccTuple can be 'still' extended
        ///
        ///
        bool IsInsertionSlotAvailable(
            CCTuple* ccTuple,
            const int index,
            llvm::Instruction* tupleGeneratingInstruction,
            const bool canExtend = true);

        void PrepareInsertionSlot(
            CCTuple* ccTuple,
            const int index,
            llvm::Instruction* tupleGeneratingInstruction,
            const bool evictFullCongruenceClass = false);

        bool CheckIntersectionForNonHomogeneous(
            const uint numOperands,
            llvm::Instruction* tupleGeneratingInstruction,
            const int offsetDiff,
            CCTuple* ccTuple);

        void ProcessTuple(llvm::Instruction* tupleGeneratingInstruction);
        void GreedyHeuristic(llvm::Instruction* tupleGeneratingInstruction);

        std::vector<CCTuple*>& GetCCTupleList()
        {
            return m_CCTupleList;
        }

        /// Get the union-root of a register. The root is 0 if the register has been
        /// isolated.
        llvm::Value* getRegRoot(llvm::Value*) const;

        ///Given the currentInstruction and root identifier of CC, find the element
        ///that belongs to CC and is a proper dominator of the currentInstruction.
        ///In straight-line codes and in separate payload and de-ssa phases, this
        ///actually should always give the results in one iteration.
        // Pop registers from the stack represented by ImmediateDominatingParent
        // until we find a parent that dominates the current instruction.
        inline llvm::Value* GetActualDominatingParent(llvm::Value* RootV, llvm::Instruction* currentInstruction)
        {
            llvm::Value* NewParent = CurrentDominatingParent[RootV];

            while (NewParent) {
                if (getRegRoot(NewParent)) {
                    //Fixme: here it does not apply.
                    // we have added the another condition because the domination-test
                    // does not work between two phi-node. See the following comments
                    // from the DT::dominates:
                    // " It is not possible to determine dominance between two PHI nodes
                    //   based on their ordering
                    //  if (isa<PHINode>(A) && isa<PHINode>(B))
                    //    return false;"
                    if (llvm::isa<llvm::Argument>(NewParent)) {
                        break;
                    }
                    else if (DT->dominates(llvm::cast<llvm::Instruction>(NewParent), currentInstruction)) {
                        break;
                    } /* else if (cast<llvm::Instruction>(NewParent)->getParent() == MBB &&
                        isa<PHINode>(DefMI) && isa<PHINode>(NewParent)) {
                            break;
                    } */
                }
                NewParent = ImmediateDominatingParent[NewParent];
            }

            return NewParent;
        }

        //Here we test the interference between the
        //Algorithm:
        //Starting from the currentDominatingParent, walk the congruence class
        //dominance tree upward, until an element that dominates the currentInstruction
        //is found.
        //Since this method could be called on the non-dominance traversal (e.g.
        //currentInstruction dominates some elements in the tree)
        // Say we have a dominance tree that is already constructed (lifetime goes
        // downwards):
        // CC dominance tree
        //    v67
        //    ^
        //    |
        //   v121 (dominating)
        //    ^
        //    |    -----   v181
        //    |
        //   v190 <- (dominated)
        //
        // Want to check the interference with v181, which dominates v190, but is dominated
        // by v121. if we would just look for a dominating element for v181, we would find
        // out that v121 is dominator of v181 and (say) it is not interfering with v181, thus
        // leading to conclusion that there is no interference between v181 and CC dominance tree.

        inline void SymmetricInterferenceTest(
            llvm::Value* RootV,
            llvm::Instruction* currentInstruction,
            llvm::Value*& dominating, //in-out
            llvm::Value*& dominated)
        {
            llvm::Value* NewParent = CurrentDominatingParent[RootV];
            dominating = nullptr;
            dominated = nullptr;

            while (NewParent)
            {
                if (getRegRoot(NewParent)) //not isolated
                {
                    if (llvm::isa<llvm::Argument>(NewParent))
                    {
                        dominating = NewParent;
                        break;
                    }
                    else if (DT->dominates(llvm::cast<llvm::Instruction>(NewParent), currentInstruction))
                    {
                        dominating = NewParent;
                        break;
                    }
                    dominated = NewParent;
                }
                NewParent = ImmediateDominatingParent[NewParent];
            }
        }

        inline CCTuple* GetValueCCTupleMapping(llvm::Value* val)
        {
            llvm::Value* RootV = getRegRoot(val);
            if (!RootV) {
                return NULL;
            }

            IGC_ASSERT(ValueNodeMap.count(RootV));
            auto RI = ValueNodeMap.find(RootV);
            ElementNode* Node = RI->second;

            auto CCI = NodeCCTupleMap.find(Node);
            if (CCI != NodeCCTupleMap.end()) {
                return CCI->second;
            }
            else {
                return NULL;
            }
        }

        /// Caller is responsible for assuring that value is not isolated
        // e.g. by calling GetCalueCCTupleMapping previously.
        inline int GetValueOffsetInCCTuple(llvm::Value* val)
        {
            llvm::Value* RootV = getRegRoot(val);
            IGC_ASSERT(nullptr != RootV);
            IGC_ASSERT(ValueNodeMap.count(RootV));

            auto RI = ValueNodeMap.find(RootV);
            ElementNode* Node = RI->second;

            auto CCI = NodeOffsetMap.find(Node);
            IGC_ASSERT(CCI != NodeOffsetMap.end());
            return CCI->second;
        }

        //////////////////////////////////////////////////////////////////////////
        class ElementFunctor {
        public:
            virtual void SetIndex(int index) = 0;
            virtual bool visitCopy() = 0;
            virtual bool visitConstant() = 0;
            virtual bool visitArgument() = 0;
            virtual bool visitIsolated() = 0;
            virtual bool visitAnchored() = 0;
            virtual bool visitInterfering(llvm::Value* val, const bool evictFullCongruenceClass) = 0;
            virtual bool visitPackedNonInterfering(llvm::Value* val) = 0;
            virtual ~ElementFunctor() {}
        };

        //////////////////////////////////////////////////////////////////////////
        class GatherWeightElementFunctor : public ElementFunctor
        {
        public:
            GatherWeightElementFunctor() :
                nAlignedAnchors(0),
                nInsertionSlotRequired(0),
                nNeedsDisplacement(0)
            {
            }

            virtual void SetIndex(int index)
            {
            }

            virtual bool visitCopy()
            {
                nInsertionSlotRequired++;
                return true;
            }

            virtual bool visitConstant()
            {
                nInsertionSlotRequired++;
                return true;
            }

            ///Not used yet, but is here in an interface
            ///for completeness.
            virtual bool visitArgument()
            {
                return true;
            }

            virtual bool visitIsolated()
            {
                nInsertionSlotRequired++;
                return true;
            }

            ///Visits constrained (anchored) element.
            virtual bool visitAnchored()
            {
                nAlignedAnchors++;
                return true;
            }

            ///Visits a value in a tuple that interferes with some (non-isolated)
            ///element in a CC class that occupies the same slot.
            virtual bool visitInterfering(
                llvm::Value* val,
                const bool evictFullCongruenceClass)
            {
                nNeedsDisplacement++;
                return true;
            }

            virtual bool visitPackedNonInterfering(llvm::Value* val)
            {
                return true;
            }

            ///Gets the number of 'anchored' elements in a tuple.
            inline int GetNumAlignedAnchors() const
            {
                return nAlignedAnchors;
            }

            inline int GetNumInsertionSlotsRequired() const
            {
                return nInsertionSlotRequired;
            }

            ///Gets the number of values in a tuple
            inline int GetNumNeedsDisplacement() const
            {
                return nNeedsDisplacement;
            }

        private:
            int nAlignedAnchors;
            int nInsertionSlotRequired;
            int nNeedsDisplacement;
        };

        //////////////////////////////////////////////////////////////////////////
        class ProcessInterferencesElementFunctor : public ElementFunctor
        {
        private:
            bool m_forceEviction;
            bool m_interferes;
            llvm::Instruction* m_tupleInst;
            const int m_offsetDiff;
            CCTuple* m_ccTuple;
            CoalescingEngine* m_CE;
            int m_index;
            llvm::SmallPtrSet<llvm::Value*, 8> m_valuesForIsolation;

        public:
            ProcessInterferencesElementFunctor(
                bool forceEviction,
                llvm::Instruction* inst,
                const int offsetDiff,
                CCTuple* ccTuple,
                CoalescingEngine* CE) :
                m_forceEviction(forceEviction),
                m_interferes(false),
                m_tupleInst(inst),
                m_offsetDiff(offsetDiff),
                m_ccTuple(ccTuple),
                m_CE(CE),
                m_index(0)
            {

            }

            llvm::SmallPtrSet<llvm::Value*, 8> & GetComputedValuesForIsolation()
            {
                return m_valuesForIsolation;
            }

            inline void SetForceEviction(bool force)
            {
                m_forceEviction = force;
            }

            inline bool IsInterfering() const
            {
                return m_interferes;
            }

            virtual void SetIndex(int index)
            {
                m_index = index;
            }

            virtual bool visitCopy()
            {
                return m_CE->EvictOrStop(
                    m_ccTuple,
                    m_index + m_offsetDiff,
                    m_tupleInst,
                    m_forceEviction,
                    m_interferes);
            }
            virtual bool visitConstant()
            {
                return m_CE->EvictOrStop(
                    m_ccTuple,
                    m_index + m_offsetDiff,
                    m_tupleInst,
                    m_forceEviction,
                    m_interferes);
            }
            virtual bool visitIsolated()
            {
                return m_CE->EvictOrStop(
                    m_ccTuple,
                    m_index + m_offsetDiff,
                    m_tupleInst,
                    m_forceEviction,
                    m_interferes);
            }

            virtual bool visitArgument()
            {
                return m_CE->EvictOrStop(
                    m_ccTuple,
                    m_index + m_offsetDiff,
                    m_tupleInst,
                    m_forceEviction,
                    m_interferes);
            }

            virtual bool visitAnchored()
            {
                return true;
            }

            virtual bool visitInterfering(llvm::Value* val, const bool evictFullCongruenceClass)
            {
                if (m_forceEviction) {

                    // HEURISTIC:
                    if (m_CE->DetermineWeight(val) < 2) {

                        m_CE->PrepareInsertionSlot(
                            m_ccTuple,
                            m_index + m_offsetDiff,
                            m_tupleInst,
                            false //evictFullCongruenceClass
                        );

                        m_valuesForIsolation.insert(val);
                    }
                    else
                    {
                        m_CE->PrepareInsertionSlot(
                            m_ccTuple,
                            m_index + m_offsetDiff,
                            m_tupleInst,
                            true //evictFullCongruenceClass
                        );

                    }
                    return true;
                }
                else {
                    m_interferes = true;
                    return false;
                }

                return true;
            }

            virtual bool visitPackedNonInterfering(llvm::Value* val)
            {
                if (m_CE->DetermineWeight(val) < 2) {
                    m_valuesForIsolation.insert(val);
                }

                return true;
            }
        };

        void ProcessElements(
            const uint numOperands,
            llvm::Instruction* tupleInst,
            const int offsetDiff,
            CCTuple* ccTuple,
            ElementFunctor* functor);

    public:

        uint GetNumPayloadElements(llvm::Instruction* inst)
        {
            if (currentPart_ == 0)
            {
                auto iter = splitPoint_.find(inst);
                if (iter == splitPoint_.end())
                {
                    //means we have no split point, can
                    return m_PayloadMapping.GetNumPayloadElements(inst);
                }
                else
                {
                    IGC_ASSERT((*iter).second > 0);
                    return (*iter).second;
                }
                //return splitPoint_
            }
            else
            {
                IGC_ASSERT(currentPart_ == 1);
                auto iter = splitPoint_.find(inst);
                IGC_ASSERT(iter != splitPoint_.end());
                return m_PayloadMapping.GetNumPayloadElements(inst) - (*iter).second;
            }
        }
        //uint GetNonAdjustedNumPayloadElements_Sample(const SampleIntrinsic *inst)
        //{
        //    return m_PayloadMapping.GetNonAdjustedNumPayloadElements_Sample(inst);
        //}

        int GetNumPayloadElements_Sample(const llvm::SampleIntrinsic* inst)
        {
            return m_PayloadMapping.GetNumPayloadElements_Sample(inst);
        }

        /// Get the mapping from the payload element (at position index)
        /// to intrinsic argument value. Indexing is zero based.
        llvm::Value* GetPayloadElementToValueMapping(const llvm::Instruction* inst, uint index)
        {
            return m_PayloadMapping.GetPayloadElementToValueMapping(inst, currentLowBound_ + index);
        }
        llvm::Value* GetPayloadElementToValueMapping_sample(const llvm::SampleIntrinsic* inst, const uint index)
        {
            return m_PayloadMapping.GetPayloadElementToValueMapping_sample(inst, index);
        }
        llvm::Value* GetNonAdjustedPayloadElementToValueMapping_sample(const llvm::SampleIntrinsic* inst, const uint index)
        {
            return m_PayloadMapping.GetNonAdjustedPayloadElementToValueMapping_sample(inst, index);
        }

        bool HasNonHomogeneousPayloadElements(const llvm::Instruction* inst)
        {
            return m_PayloadMapping.HasNonHomogeneousPayloadElements(inst);
        }
        int GetLeftReservedOffset(const llvm::Instruction* inst, SIMDMode simdMode)
        {
            return m_PayloadMapping.GetLeftReservedOffset(inst, simdMode);
        }

        int GetRightReservedOffset(const llvm::Instruction* inst, SIMDMode simdMode)
        {
            return m_PayloadMapping.GetRightReservedOffset(inst, simdMode);
        }
        const llvm::Instruction* GetSupremumOfNonHomogeneousPart(
            const llvm::Instruction* inst1,
            const llvm::Instruction* inst2)
        {
            return m_PayloadMapping.GetSupremumOfNonHomogeneousPart(inst1, inst2);
        }

        uint GetNumSplitParts(llvm::Instruction* inst)
        {
            auto iter = splitPoint_.find(inst);
            if (iter != splitPoint_.end())
            {
                uint splitIndex = (*iter).second;
                return splitIndex > 0 ? 2 : 1;
            }
            else
            {
                return 1;
            }
        }

        void SetCurrentPart(llvm::Instruction* inst, unsigned int partNum)
        {
            if (partNum == 0)
            {
                currentLowBound_ = 0;
                currentPart_ = partNum;
                //            currentUpperBound_ = splitPoint_[inst];
            }
            else
            {
                IGC_ASSERT(partNum == 1);
                currentLowBound_ = splitPoint_[inst];
                IGC_ASSERT(currentLowBound_ > 0);
                currentPart_ = partNum;
            }
        }

    private:

        CPlatform m_Platform;
        PayloadMapping m_PayloadMapping;
        std::vector<CCTuple*> m_CCTupleList;
        llvm::DominatorTree* DT;
        LiveVars* LV;
        WIAnalysis* WIA;
        DeSSA* m_DeSSA;
        CodeGenPatternMatch* CG;
        llvm::DenseMap<llvm::Value*, ElementNode*> ValueNodeMap;
        llvm::DenseMap<ElementNode*, CCTuple*> NodeCCTupleMap;
        //Mapping root element node to its offset in cc tuple:
        llvm::DenseMap<ElementNode*, int> NodeOffsetMap;
        llvm::DenseMap<llvm::Value*, uint> ValueWeightMap;
        ModuleMetaData* m_ModuleMetadata;
        CodeGenContext* m_CodeGenContext;
        //Maps a basic block to a list of instruction defs to be processed for coalescing (in dominance order)
        llvm::DenseMap<llvm::BasicBlock*, std::vector<llvm::Instruction*> > BBProcessingDefs;


        /* Taken from strong DE SSA */
        // Perform a depth-first traversal of the dominator tree, splitting
        // interferences amongst PHI-congruence classes.

        llvm::BumpPtrAllocator Allocator;

        llvm::DenseMap<llvm::Value*, llvm::Value*> CurrentDominatingParent;
        llvm::DenseMap<llvm::Value*, llvm::Value*> ImmediateDominatingParent;

        llvm::DenseMap<llvm::Instruction*, uint> splitPoint_;
        unsigned currentLowBound_;
        //unsigned currentUpperBound_;
        unsigned currentPart_;

        /// Get the union-root of a PHI. The root of a PHI is 0 if the PHI has been
        /// isolated. Otherwise, it is the original root of its destination and
        /// all of its operands (before they were isolated, if they were).
        llvm::Value* getPHIRoot(llvm::Instruction*) const;

        void unionRegs(llvm::Value*, llvm::Value*);

        bool isUniform(llvm::Value* v) const {
            return (WIA->whichDepend(v) == WIAnalysis::UNIFORM);
        }

        // Isolate a register.
        void isolateReg(llvm::Value* Val) {
            ElementNode* Node = ValueNodeMap[Val];
            Node->parent.setInt(Node->parent.getInt() | ElementNode::kRegisterIsolatedFlag);
        }
        /* Taken from strong DE SSA */



        struct MIIndexCompare {
            MIIndexCompare(LiveVars* _lv) : LV(_lv) { }

            bool operator()(const llvm::Instruction* LHS, const llvm::Instruction* RHS) const {
                return LV->getDistance(LHS) < LV->getDistance(RHS);
            }

            LiveVars* LV;
        };

        bool isCoalescedByDeSSA(llvm::Value* V) const;
    };

} //namespace IGC
