UnrealEngineUWP/Engine/Plugins/Mutable/Source/MutableTools/Private/MuT/CodeOptimiser_Parameters.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "MuT/AST.h"
#include "MuT/ASTOpAddLOD.h"
#include "MuT/ASTOpConditional.h"
#include "MuT/ASTOpImageCompose.h"
#include "MuT/ASTOpImageMipmap.h"
#include "MuT/ASTOpImagePixelFormat.h"
#include "MuT/ASTOpImageLayer.h"
#include "MuT/ASTOpImageLayerColor.h"
#include "MuT/ASTOpMeshMorph.h"
#include "MuT/ASTOpInstanceAdd.h"
#include "MuT/ASTOpLayoutFromMesh.h"
#include "MuT/ASTOpParameter.h"
#include "MuT/CodeOptimiser.h"
#include "MuT/Compiler.h"
#include "MuT/CompilerPrivate.h"
#include "MuT/DataPacker.h"
#include "MuT/Platform.h"
#include "MuR/Image.h"
#include "MuR/ImagePrivate.h"
#include "MuR/MutableTrace.h"
#include "MuR/Operations.h"
#include "MuR/ParametersPrivate.h"
#include "MuR/Platform.h"
#include "MuR/Ptr.h"
#include "MuR/RefCounted.h"
#include "MuR/MutableRuntimeModule.h"

#include "HAL/PlatformCrt.h"
#include "HAL/PlatformMath.h"
#include "Logging/LogCategory.h"
#include "Logging/LogMacros.h"
#include "Misc/AssertionMacros.h"
#include "Trace/Detail/Channel.h"

#include <array>


namespace mu
{

    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    RuntimeParameterVisitorAST::RuntimeParameterVisitorAST(const FStateCompilationData* pState)
        : m_pState(pState)
    {
    }


    bool RuntimeParameterVisitorAST::HasAny( const Ptr<ASTOp>& root )
    {
        if (!m_pState->nodeState.RuntimeParams.Num())
        {
            return false;
        }

        // Shortcut flag: if true we already found a runtime parameter, don't process new ops,
        // but still store the results of processed ops.
        bool found = false;

        m_pending.clear();

        PENDING_ITEM start;
        start.at = root;
        start.itemType = 0;
        start.onlyLayoutsRelevant = 0;
        m_pending.push_back( start );

        // Don't early out to be able to complete parent op cached flags
        while ( m_pending.size() )
        {
            PENDING_ITEM item = m_pending.back();
            m_pending.pop_back();
            Ptr<ASTOp> at = item.at;

			if (!at)
			{
				continue;
			}

            // Not cached?
            if ( m_visited[at]!=OP_STATE::VISITED_HASRUNTIME
                 &&
                 m_visited[at]!=OP_STATE::VISITED_FULL_DOESNTHAVERUNTIME )
            {
                if (item.itemType)
                {
                    // Item indicating we finished with all the children of a parent
                    check( m_visited[at]==OP_STATE::CHILDREN_PENDING_FULL
                                    ||
                                    m_visited[at]==OP_STATE::CHILDREN_PENDING_PARTIAL
                                    ||
                                    m_visited[at]==OP_STATE::VISITED_PARTIAL_DOESNTHAVERUNTIME );

                    bool subtreeFound = false;
                    at->ForEachChild( [&](ASTChild& ref)
                    {
                        subtreeFound = subtreeFound || m_visited[ref.child()]==OP_STATE::VISITED_HASRUNTIME;
                    });

                    if (subtreeFound)
                    {
                        m_visited[at] = OP_STATE::VISITED_HASRUNTIME;
                    }
                    else
                    {
                        m_visited[at] = item.onlyLayoutsRelevant
                                ? OP_STATE::VISITED_PARTIAL_DOESNTHAVERUNTIME
                                : OP_STATE::VISITED_FULL_DOESNTHAVERUNTIME;
                    }
                }

                else if (!found)
                {
                    // We need to process the subtree
                    check( m_visited[at]==OP_STATE::NOT_VISITED
                                    ||
                                    ( m_visited[at]==OP_STATE::VISITED_PARTIAL_DOESNTHAVERUNTIME
                                      &&
                                      item.onlyLayoutsRelevant==0 )
                                    );

                    // Request the processing of the end of this instruction
                    PENDING_ITEM endItem = item;
                    endItem.itemType = 1;
                    m_pending.push_back( endItem );
                    m_visited[at] = item.onlyLayoutsRelevant
                            ? OP_STATE::CHILDREN_PENDING_PARTIAL
                            : OP_STATE::CHILDREN_PENDING_FULL;

                    // Is it a special op type?
                    switch ( at->GetOpType() )
                    {

                    case OP_TYPE::BO_PARAMETER:
                    case OP_TYPE::NU_PARAMETER:
                    case OP_TYPE::SC_PARAMETER:
                    case OP_TYPE::CO_PARAMETER:
                    case OP_TYPE::PR_PARAMETER:
                    case OP_TYPE::IM_PARAMETER:
                    {
						const ASTOpParameter* typed = static_cast<const ASTOpParameter*>(at.get());
                        const TArray<FString>& params = m_pState->nodeState.RuntimeParams;
                        if ( params.Find( typed->parameter.m_name)
                             !=
                             INDEX_NONE )
                        {
                            found = true;
                            m_visited[at] = OP_STATE::VISITED_HASRUNTIME;
                        }
                        break;
                    }

                    case OP_TYPE::ME_INTERPOLATE:
                    {
						const ASTOpFixed* typed = static_cast<const ASTOpFixed*>(at.get());
                        PENDING_ITEM childItem;
                        childItem.itemType = 0;
                        childItem.onlyLayoutsRelevant = item.onlyLayoutsRelevant;

                        if ( item.onlyLayoutsRelevant==0 )
                        {
                            childItem.at = typed->children[typed->op.args.MeshInterpolate.factor].child();
                            AddIfNeeded(childItem);
                        }

                        childItem.at = typed->children[typed->op.args.MeshInterpolate.base].child();
                        AddIfNeeded(childItem);

                        for (int32 t=0;t<MUTABLE_OP_MAX_INTERPOLATE_COUNT-1;++t)
                        {
                            childItem.at = typed->children[typed->op.args.MeshInterpolate.targets[t]].child();
                            AddIfNeeded(childItem);
                        }

                        break;
                    }

                    default:
                    {
                        at->ForEachChild([&](ASTChild& ref)
                        {
                            PENDING_ITEM childItem;
                            childItem.itemType = 0;
                            childItem.at = ref.child();
                            childItem.onlyLayoutsRelevant = item.onlyLayoutsRelevant;
                            AddIfNeeded(childItem);
                        });
                        break;
                    }

                    }

                }

                else
                {
                    // We won't process it.
                    m_visited[at] = OP_STATE::NOT_VISITED;
                }
            }
        }

        return m_visited[root]==OP_STATE::VISITED_HASRUNTIME;
    }


    void RuntimeParameterVisitorAST::AddIfNeeded( const PENDING_ITEM& item )
    {
        if (item.at)
        {
            if (m_visited[item.at]==OP_STATE::NOT_VISITED)
            {
                m_pending.push_back( item );
            }
            else if (m_visited[item.at]==OP_STATE::VISITED_PARTIAL_DOESNTHAVERUNTIME
                     &&
                     item.onlyLayoutsRelevant==0)
            {
                m_pending.push_back( item );
            }
            else if (m_visited[item.at]==OP_STATE::CHILDREN_PENDING_PARTIAL
                     &&
                     item.onlyLayoutsRelevant==0)
            {
                m_pending.push_back( item );
            }
        }
    }


    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    Ptr<ASTOp> EnsureValidMask( Ptr<ASTOp> mask, Ptr<ASTOp> base )
    {
        if ( !mask )
        {
            Ptr<ASTOpFixed> whiteOp = new ASTOpFixed;
            whiteOp->op.type = OP_TYPE::CO_CONSTANT;
            whiteOp->op.args.ColourConstant.value[0] = 1;
            whiteOp->op.args.ColourConstant.value[1] = 1;
			whiteOp->op.args.ColourConstant.value[2] = 1;
			whiteOp->op.args.ColourConstant.value[3] = 1;

            Ptr<ASTOpFixed> wplainOp = new ASTOpFixed;
            wplainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
            wplainOp->SetChild( wplainOp->op.args.ImagePlainColour.colour, whiteOp );
            wplainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE;
            wplainOp->op.args.ImagePlainColour.size[0] = 4;
			wplainOp->op.args.ImagePlainColour.size[1] = 4;
			wplainOp->op.args.ImagePlainColour.LODs = 1;

            Ptr<ASTOpFixed> wresizeOp = new ASTOpFixed;
            wresizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
            wresizeOp->SetChild( wresizeOp->op.args.ImageResizeLike.source, wplainOp );
            wresizeOp->SetChild( wresizeOp->op.args.ImageResizeLike.sizeSource, base );

            mask = wresizeOp;
        }

        return mask;
    }


    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    ParameterOptimiserAST::ParameterOptimiserAST(
		FStateCompilationData& s,
            const FModelOptimizationOptions& optimisationOptions
            )
            : m_stateProps(s)
            , m_modified(false)
            , OptimisationOptions(optimisationOptions)
            , m_hasRuntimeParamVisitor(&s)
    {
    }


    bool ParameterOptimiserAST::Apply()
    {
        MUTABLE_CPUPROFILER_SCOPE(ParameterOptimiserAST);

        m_modified = false;

        // Optimise the cloned tree
        Traverse( m_stateProps.root );

        return m_modified;
    }


    Ptr<ASTOp> ParameterOptimiserAST::Visit( Ptr<ASTOp> at, bool& processChildren )
    {
        // Only process children if there are runtime parameters in the subtree
        processChildren = m_hasRuntimeParamVisitor.HasAny(at);

        OP_TYPE type = at->GetOpType();
        switch ( type )
        {
        //-------------------------------------------------------------------------------------
        // Be careful with changing merge options and "mergesurfaces" flags
//        case OP_TYPE::ME_MERGE:
//        {
//            OP::MeshMergeArgs mergeArgs = program.m_code[at].args.MeshMerge;

//            RuntimeParameterVisitor paramVis;

//            switch ( program.m_code[ mergeArgs.base ].type )
//            {
//            case OP_TYPE::ME_CONDITIONAL:
//            {
//                OP::ADDRESS conditionAt =
//                        program.m_code[ mergeArgs.base ].args.Conditional.condition;
//                bool conditionConst = !paramVis.HasAny( m_pModel.get(),
//                                                        m_state,
//                                                        conditionAt );
//                if ( conditionConst )
//                {
//                    // TODO: this may unfold mesh combinations of some models increasing the size of
//                    // the model data. Make this optimisation optional.
//                    m_modified = true;

//                    OP yesOp = program.m_code[at];
//                    yesOp.args.MeshMerge.base = program.m_code[ mergeArgs.base ].args.Conditional.yes;

//                    OP noOp = program.m_code[at];
//                    noOp.args.MeshMerge.base = program.m_code[ mergeArgs.base ].args.Conditional.no;

//                    OP op = program.m_code[ mergeArgs.base ];
//                    op.args.Conditional.yes = program.AddOp( yesOp );
//                    op.args.Conditional.no = program.AddOp( noOp );
//                    at = program.AddOp( op );
//                }

//                break;
//            }

//            case OP_TYPE::ME_MERGE:
//            {
//                OP::ADDRESS childBaseAt = program.m_code[ mergeArgs.base ].args.MeshMerge.base;
//                bool childBaseConst = !paramVis.HasAny( m_pModel.get(),
//                                                        m_state,
//                                                        childBaseAt );

//                OP::ADDRESS childAddAt = program.m_code[ mergeArgs.base ].args.MeshMerge.added;
//                bool childAddConst = !paramVis.HasAny( m_pModel.get(),
//                                                       m_state,
//                                                       childAddAt );

//                bool addConst = !paramVis.HasAny( m_pModel.get(),
//                                                  m_state,
//                                                  mergeArgs.added );

//                if ( !childBaseConst && childAddConst && addConst )
//                {
//                    m_modified = true;

//                    OP bottom = program.m_code[at];
//                    bottom.args.MeshMerge.base = childAddAt;

//                    OP top = program.m_code[ mergeArgs.base ];
//                    top.args.MeshMerge.added = program.AddOp( bottom );
//                    at = program.AddOp( top );
//                }
//                break;
//            }

//            default:
//                break;
//            }

//            break;
//        }

        //-------------------------------------------------------------------------------------
        //-------------------------------------------------------------------------------------
        //-------------------------------------------------------------------------------------
        case OP_TYPE::IM_CONDITIONAL:
        {
			const ASTOpConditional* typedAt = static_cast<const ASTOpConditional*>(at.get());

            // If the condition is not runtime, but the branches are, try to move the
            // conditional down
            bool optimised = false;

            if ( !m_hasRuntimeParamVisitor.HasAny( typedAt->condition.child() ) )
            {
                OP_TYPE yesType = typedAt->yes->GetOpType();
                OP_TYPE noType = typedAt->no->GetOpType();

                bool yesHasAny = m_hasRuntimeParamVisitor.HasAny( typedAt->yes.child() );
                bool noHasAny = m_hasRuntimeParamVisitor.HasAny( typedAt->no.child() );

                if ( !optimised && yesHasAny && noHasAny && yesType==noType)
                {
                    switch (yesType)
                    {
                        case OP_TYPE::IM_COMPOSE:
                        {
						const ASTOpImageCompose* typedYes = static_cast<const ASTOpImageCompose*>(typedAt->yes.child().get());
						const ASTOpImageCompose* typedNo = static_cast<const ASTOpImageCompose*>(typedAt->no.child().get());
                        if ( typedYes->BlockId == typedNo->BlockId
                             &&
                             (
                                 (typedYes->Mask.child().get() != nullptr)
                                  ==
                                 (typedNo->Mask.child().get() != nullptr)
                                )
                             )
                            {
                                // Move the conditional down
                                Ptr<ASTOpImageCompose> compOp = mu::Clone<ASTOpImageCompose>(typedYes);

                                Ptr<ASTOpConditional> baseCond = mu::Clone<ASTOpConditional>(typedAt);
                                baseCond->yes = typedYes->Base.child();
                                baseCond->no = typedNo->Base.child();
                                compOp->Base = baseCond;

                                Ptr<ASTOpConditional> blockCond = mu::Clone<ASTOpConditional>(typedAt);
                                blockCond->yes = typedYes->BlockImage.child();
                                blockCond->no = typedNo->BlockImage.child();
                                compOp->BlockImage = blockCond;

                                if (typedYes->Mask)
                                {
                                    Ptr<ASTOpConditional> maskCond = mu::Clone<ASTOpConditional>(typedAt);
                                    maskCond->yes = typedYes->Mask.child();
                                    maskCond->no = typedNo->Mask.child();
                                    compOp->Mask = maskCond;
                                }

                                Ptr<ASTOpConditional> layCond = mu::Clone<ASTOpConditional>(typedAt);
                                layCond->type = OP_TYPE::LA_CONDITIONAL;
                                layCond->yes = typedYes->Layout.child();
                                layCond->no = typedNo->Layout.child();
                                compOp->Layout = layCond;


                                at = compOp;
                                optimised = true;
                            }
                            break;
                        }

                    default:
                        break;

                    }
                }

                if ( !optimised && yesHasAny )
                {
                    switch (yesType)
                    {
                        case OP_TYPE::IM_LAYERCOLOUR:
                        {
                            optimised = true;

							const ASTOpImageLayerColor* typedYes = static_cast<const ASTOpImageLayerColor*>(typedAt->yes.child().get());

                            Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                            blackOp->op.type = OP_TYPE::CO_CONSTANT;
                            blackOp->op.args.ColourConstant.value[0] = 0;
                            blackOp->op.args.ColourConstant.value[1] = 0;
							blackOp->op.args.ColourConstant.value[2] = 0;
							blackOp->op.args.ColourConstant.value[3] = 1;

                            Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                            plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                            plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                            plainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE;
                            plainOp->op.args.ImagePlainColour.size[0] = 4;
							plainOp->op.args.ImagePlainColour.size[1] = 4;
							plainOp->op.args.ImagePlainColour.LODs = 1;

                            Ptr<ASTOpFixed> resizeOp = new ASTOpFixed;
                            resizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                            resizeOp->SetChild( resizeOp->op.args.ImageResizeLike.source, plainOp );
                            resizeOp->SetChild( resizeOp->op.args.ImageResizeLike.sizeSource, typedYes->base );

                            Ptr<ASTOpConditional> maskOp = mu::Clone<ASTOpConditional>(typedAt);
                            maskOp->no = resizeOp;

                            // If there is no mask (because it is optional), we need to make a
                            // white plain image
                            maskOp->yes = EnsureValidMask( typedYes->mask.child(), typedYes->base.child() );

							Ptr<ASTOpConditional> baseOp = mu::Clone<ASTOpConditional>(typedAt);
                            baseOp->yes = typedYes->base.child();

                            Ptr<ASTOpImageLayerColor> softOp = mu::Clone<ASTOpImageLayerColor>(typedYes);
                            softOp->base = baseOp;
                            softOp->mask = maskOp;

                            at = softOp;
                            break;
                        }

                        // TODO
                        // It seems this is not worth since it replaces a conditional by a compose
                        // (but only at build time, not update?) and it introduces the use of masks
                        // and resize likes... plus masks can't always be used if BC formats.
//						case OP_TYPE::IM_COMPOSE:
//						{
//							optimised = true;

//							OP blackOp;
//							blackOp.type = OP_TYPE::CO_CONSTANT;
//							blackOp.args.ColourConstant.value[0] = 0;
//							blackOp.args.ColourConstant.value[1] = 0;
//							blackOp.args.ColourConstant.value[2] = 0;
//							blackOp.args.ColourConstant.value[3] = 1;

//							OP plainOp;
//							plainOp.type = OP_TYPE::IM_PLAINCOLOUR;
//							plainOp.args.ImagePlainColour.colour = program.AddOp( blackOp );
//							plainOp.args.ImagePlainColour.format = IF_L_UBYTE;
//							plainOp.args.ImagePlainColour.size = ;
//							plainOp.args.ImagePlainColour.LODs = ;

//							OP resizeOp;
//							resizeOp.type = OP_TYPE::IM_RESIZELIKE;
//							resizeOp.args.ImageResizeLike.source = program.AddOp( plainOp );
//							resizeOp.args.ImageResizeLike.sizeSource =
//									program.m_code[args.yes].args.ImageCompose.blockImage;

//							OP maskOp = program.m_code[at];
//							maskOp.args.Conditional.no = program.AddOp( resizeOp );

//							// If there is no mask (because it is optional), we need to make a
//							// white plain image
//							maskOp.args.Conditional.yes = EnsureValidMask
//									( program.m_code[args.yes].args.ImageCompose.mask,
//									  program.m_code[args.yes].args.ImageCompose.base,
//									  program );

//							OP baseOp = program.m_code[at];
//							baseOp.args.Conditional.yes =
//									program.m_code[args.yes].args.ImageCompose.base;

//							OP composeOp = program.m_code[args.yes];
//							composeOp.args.ImageCompose.base = program.AddOp( baseOp );
//							composeOp.args.ImageCompose.mask = program.AddOp( maskOp );

//							at = program.AddOp( composeOp );

//							// Process the new children
//							at = Recurse( at, program );
//							break;
//						}

                        default:
                            break;

                    }
                }

                else if ( !optimised && noHasAny )
                {
                    switch (noType)
                    {
                        case OP_TYPE::IM_LAYERCOLOUR:
                        {
                            optimised = true;

                            const ASTOpImageLayerColor* typedNo = static_cast<const ASTOpImageLayerColor*>(typedAt->no.child().get());

                            Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                            blackOp->op.type = OP_TYPE::CO_CONSTANT;
                            blackOp->op.args.ColourConstant.value[0] = 0;
                            blackOp->op.args.ColourConstant.value[1] = 0;
							blackOp->op.args.ColourConstant.value[2] = 0;
							blackOp->op.args.ColourConstant.value[3] = 1;

                            Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                            plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                            plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                            plainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE;
                            plainOp->op.args.ImagePlainColour.size[0] = 4;
							plainOp->op.args.ImagePlainColour.size[1] = 4;
							plainOp->op.args.ImagePlainColour.LODs = 1;

                            Ptr<ASTOpFixed> resizeOp = new ASTOpFixed;
                            resizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                            resizeOp->SetChild( resizeOp->op.args.ImageResizeLike.source, plainOp );
                            resizeOp->SetChild( resizeOp->op.args.ImageResizeLike.sizeSource, typedNo->base );

                            Ptr<ASTOpConditional> maskOp = mu::Clone<ASTOpConditional>(typedAt);
                            maskOp->no = resizeOp;

                            // If there is no mask (because it is optional), we need to make a
                            // white plain image
                            maskOp->no = EnsureValidMask( typedNo->mask.child(), typedNo->base.child() );

                            Ptr<ASTOpConditional> baseOp = mu::Clone<ASTOpConditional>(typedAt);
                            baseOp->no = typedNo->base.child();

                            Ptr<ASTOpImageLayerColor> softOp = mu::Clone<ASTOpImageLayerColor>(typedNo);
                            softOp->base = baseOp;
                            softOp->mask = maskOp;

                            at = softOp;
                            break;
                        }

                        default:
                            break;

                    }
                }
            }

            m_modified |= optimised;

            break;
        }


        //-------------------------------------------------------------------------------------
        case OP_TYPE::IM_SWITCH:
        {
            // If the switch is not runtime, but the branches are, try to move the
            // switch down
//            bool optimised = false;

//            OP::ADDRESS variable = program.m_code[at].args.Switch.variable;

//            if ( !m_hasRuntimeParamVisitor.HasAny( variable, program ) )
//            {
//                SWITCH_CHAIN chain = GetSwitchChain( program, at );

//                bool branchHasAny = false;
//                OP_TYPE branchType = (OP_TYPE)program.m_code[program.m_code[at].args.Switch.values[0]].type;
//                for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                      it != chain.cases.end();
//                      ++it )
//                {
//                    if ( program.m_code[it->second].type != branchType )
//                    {
//                        branchType = OP_TYPE::NONE;
//                    }
//                    else
//                    {
//                        if (!branchHasAny)
//                        {
//                            branchHasAny = m_hasRuntimeParamVisitor.HasAny( it->second, program );
//                        }
//                    }
//                }

//                if ( chain.def && program.m_code[chain.def].type != branchType )
//                {
//                    branchType = OP_TYPE::NONE;
//                }

//                // Some branch in runtime
//                if ( branchHasAny )
//                {
//                    switch ( branchType )
//                    {

//                    // TODO: Other operations
//                    case OP_TYPE::IM_BLEND:
//                    case OP_TYPE::IM_MULTIPLY:
//                    {
//                        // Move the switch down the base
//                        OP::ADDRESS baseAt = 0;
//                        for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                              it != chain.cases.end();
//                              )
//                        {
//                            OP bsw;
//                            bsw.type = OP_TYPE::IM_SWITCH;
//                            bsw.args.Switch.variable = variable;

//                            for ( int b=0;
//                                  it != chain.cases.end() && b<MUTABLE_OP_MAX_SWITCH_OPTIONS;
//                                  ++b )
//                            {
//                                bsw.args.Switch.conditions[b] = it->first;
//                                bsw.args.Switch.values[b] =
//                                        program.m_code[it->second].args.ImageLayer.base;
//                                ++it;
//                            }

//                            bsw.args.Switch.def = baseAt;
//                            baseAt = program.AddOp( bsw );
//                        }

//                        // Move the switch down the mask
//                        OP::ADDRESS maskAt = 0;
//                        for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                              it != chain.cases.end();
//                              )
//                        {
//                            OP bsw;
//                            bsw.type = OP_TYPE::IM_SWITCH;
//                            bsw.args.Switch.variable = variable;

//                            for ( int b=0;
//                                  it != chain.cases.end() && b<MUTABLE_OP_MAX_SWITCH_OPTIONS;
//                                  ++b )
//                            {
//                                bsw.args.Switch.conditions[b] = it->first;
//                                bsw.args.Switch.values[b] =
//                                        program.m_code[it->second].args.ImageLayer.mask;
//                                ++it;
//                            }

//                            bsw.args.Switch.def = maskAt;
//                            maskAt = program.AddOp( bsw );
//                        }

//                        // Move the switch down the blended
//                        OP::ADDRESS blendedAt = 0;
//                        for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                              it != chain.cases.end();
//                              )
//                        {
//                            OP bsw;
//                            bsw.type = OP_TYPE::IM_SWITCH;
//                            bsw.args.Switch.variable = variable;

//                            for ( int b=0;
//                                  it != chain.cases.end() && b<MUTABLE_OP_MAX_SWITCH_OPTIONS;
//                                  ++b )
//                            {
//                                bsw.args.Switch.conditions[b] = it->first;
//                                bsw.args.Switch.values[b] =
//                                        program.m_code[it->second].args.ImageLayer.blended;
//                                ++it;
//                            }

//                            bsw.args.Switch.def = blendedAt;
//                            blendedAt = program.AddOp( bsw );
//                        }

//                        OP top;
//                        top.type = branchType;
//                        top.args.ImageLayer.base = baseAt;
//                        top.args.ImageLayer.mask = maskAt;
//                        top.args.ImageLayer.blended = blendedAt;
//                        at = program.AddOp( top );
//                        optimised = true;
//                        break;
//                    }


//                    // TODO: Other operations
//                    case OP_TYPE::IM_SOFTLIGHTCOLOUR:
//                    {
//                        // Move the switch down the base
//                        OP::ADDRESS baseAt = 0;
//                        for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                              it != chain.cases.end();
//                              )
//                        {
//                            OP bsw;
//                            bsw.type = OP_TYPE::IM_SWITCH;
//                            bsw.args.Switch.variable = variable;

//                            for ( int b=0;
//                                  it != chain.cases.end() && b<MUTABLE_OP_MAX_SWITCH_OPTIONS;
//                                  ++b )
//                            {
//                                bsw.args.Switch.conditions[b] = it->first;
//                                bsw.args.Switch.values[b] =
//                                        program.m_code[it->second].args.ImageLayerColour.base;
//                                ++it;
//                            }

//                            bsw.args.Switch.def = baseAt;
//                            baseAt = program.AddOp( bsw );
//                        }

//                        // Move the switch down the mask
//                        OP::ADDRESS maskAt = 0;
//                        for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                              it != chain.cases.end();
//                              )
//                        {
//                            OP bsw;
//                            bsw.type = OP_TYPE::IM_SWITCH;
//                            bsw.args.Switch.variable = variable;

//                            for ( int b=0;
//                                  it != chain.cases.end() && b<MUTABLE_OP_MAX_SWITCH_OPTIONS;
//                                  ++b )
//                            {
//                                bsw.args.Switch.conditions[b] = it->first;
//                                bsw.args.Switch.values[b] =
//                                        program.m_code[it->second].args.ImageLayerColour.mask;
//                                ++it;
//                            }

//                            bsw.args.Switch.def = maskAt;
//                            maskAt = program.AddOp( bsw );
//                        }

//                        // Move the switch down the colour
//                        OP::ADDRESS colourAt = 0;
//                        for ( map<uint16,OP::ADDRESS>::const_iterator it=chain.cases.begin();
//                              it != chain.cases.end();
//                              )
//                        {
//                            OP bsw;
//                            bsw.type = OP_TYPE::CO_SWITCH;
//                            bsw.args.Switch.variable = variable;

//                            for ( int b=0;
//                                  it != chain.cases.end() && b<MUTABLE_OP_MAX_SWITCH_OPTIONS;
//                                  ++b )
//                            {
//                                bsw.args.Switch.conditions[b] = it->first;
//                                bsw.args.Switch.values[b] =
//                                        program.m_code[it->second].args.ImageLayerColour.colour;
//                                ++it;
//                            }

//                            bsw.args.Switch.def = colourAt;
//                            colourAt = program.AddOp( bsw );
//                        }

//                        OP top;
//                        top.type = branchType;
//                        top.args.ImageLayerColour.base = baseAt;
//                        top.args.ImageLayerColour.mask = maskAt;
//                        top.args.ImageLayerColour.colour = colourAt;
//                        at = program.AddOp( top );
//                        optimised = true;
//                        break;
//                    }


//                    default:
//                        break;

//                    }
//                }

//            }

//            m_modified |= optimised;

            break;
        }


        //-----------------------------------------------------------------------------------------
        case OP_TYPE::IM_COMPOSE:
        {
			const ASTOpImageCompose* typedAt = static_cast<const ASTOpImageCompose*>(at.get());

            Ptr<ASTOp> blockAt = typedAt->BlockImage.child();
			Ptr<ASTOp> baseAt = typedAt->Base.child();
			Ptr<ASTOp> layoutAt = typedAt->Layout.child();

			if (!blockAt)
			{
				at = baseAt;
				break;
			}

            OP_TYPE blockType = blockAt->GetOpType();
            OP_TYPE baseType = baseAt->GetOpType();

            bool baseHasRuntime = m_hasRuntimeParamVisitor.HasAny( baseAt );
            bool blockHasRuntime = m_hasRuntimeParamVisitor.HasAny( blockAt );
            bool layoutHasRuntime = m_hasRuntimeParamVisitor.HasAny( layoutAt );

            bool optimised = false;

            // Try to optimise base and block together, if possible
            if ( blockHasRuntime && baseHasRuntime && !layoutHasRuntime )
            {
                if ( baseType == blockType )
                {
                    switch ( blockType )
                    {
                    case OP_TYPE::IM_LAYERCOLOUR:
                    {
                        optimised = true;

						const ASTOpImageLayerColor* typedBaseAt = static_cast<const ASTOpImageLayerColor*>(baseAt.get());
						const ASTOpImageLayerColor* typedBlockAt = static_cast<const ASTOpImageLayerColor*>(blockAt.get());

                        // The mask is a compose of the block mask on the base mask, but if none has
                        // a mask we don't need to make one.
						Ptr<ASTOp> baseImage = typedBaseAt->base.child();
						Ptr<ASTOp> baseMask = typedBaseAt->mask.child();
						Ptr<ASTOp> blockImage = typedBlockAt->base.child();
						Ptr<ASTOp> blockMask = typedBlockAt->mask.child();

                        Ptr<ASTOpImageCompose> maskOp;
                        if (baseMask || blockMask)
                        {
                            // \TODO: BLEH! This may create a discrepancy of number of mips between
                            // the base image and the mask This is for now solved with emergy fix
                            // c36adf47-e40d-490f-b709-41142bafad78
							Ptr<ASTOp> newBaseMask = EnsureValidMask(baseMask, baseImage);
							Ptr<ASTOp> newBlockMask = EnsureValidMask(blockMask, blockImage);

                            maskOp = mu::Clone<ASTOpImageCompose>(typedAt);
                            maskOp->Base = newBaseMask;
                            maskOp->BlockImage = newBlockMask;
                        }

                        // The base is composition of the bases of both layer effect
						Ptr<ASTOpImageCompose> baseOp = mu::Clone<ASTOpImageCompose>(typedAt);
                        baseOp->Base = baseImage;
                        baseOp->BlockImage = blockImage;

                        Ptr<ASTOpImageLayerColor> nop = mu::Clone<ASTOpImageLayerColor>(blockAt);
                        nop->mask = maskOp;
                        nop->base = baseOp;

                        // Done
                        at = nop;
                        break;
                    }

                    case OP_TYPE::IM_LAYER:
                    {
                        optimised = true;

						const ASTOpImageLayer* typedBaseAt = static_cast<const ASTOpImageLayer*>(baseAt.get());
						const ASTOpImageLayer* typedBlockAt = static_cast<const ASTOpImageLayer*>(blockAt.get());

                        // The mask is a compose of the block mask on the base mask, but if none has
                        // a mask we don't need to make one.
						Ptr<ASTOp> baseImage = typedBaseAt->base.child();
						Ptr<ASTOp> baseBlended = typedBaseAt->blend.child();
						Ptr<ASTOp> baseMask = typedBaseAt->mask.child();
						Ptr<ASTOp> blockImage = typedBlockAt->base.child();
						Ptr<ASTOp> blockBlended = typedBlockAt->blend.child();
						Ptr<ASTOp> blockMask = typedBlockAt->mask.child();

                        Ptr<ASTOpImageCompose> maskOp;
                        if (baseMask || blockMask)
                        {
                            // \TODO: BLEH! This may create a discrepancy of number of mips between
                            // the base image and the mask This is for now solved with emergy fix
                            // c36adf47-e40d-490f-b709-41142bafad78
							Ptr<ASTOp> newBaseMask = EnsureValidMask(baseMask, baseImage);
							Ptr<ASTOp> newBlockMask = EnsureValidMask(blockMask, blockImage);

                            maskOp = mu::Clone<ASTOpImageCompose>(typedAt);
                            maskOp->Base = newBaseMask;
                            maskOp->BlockImage = newBlockMask;
                        }

                        // The base is composition of the bases of both layer effect
						Ptr<ASTOpImageCompose> baseOp = mu::Clone<ASTOpImageCompose>(typedAt);
                        baseOp->Base = baseImage;
                        baseOp->BlockImage = blockImage;

                        // The base is composition of the bases of both layer effect
						Ptr<ASTOpImageCompose> blendedOp = mu::Clone<ASTOpImageCompose>(typedAt);
                        blendedOp->Base = baseBlended;
                        blendedOp->BlockImage = blockBlended;

                        Ptr<ASTOpImageLayer> nop = mu::Clone<ASTOpImageLayer>(blockAt);
                        nop->mask = maskOp;
                        nop->base = baseOp;
                        nop->blend = blendedOp;

                        // Done
                        at = nop;
                        break;
                    }

                    default:
                        break;
                    }
                }
            }


            // Swap two composes
            if ( !optimised && baseHasRuntime && !blockHasRuntime
                 &&
                 baseType == OP_TYPE::IM_COMPOSE )
            {
				const ASTOpImageCompose* typedBaseAt = static_cast<const ASTOpImageCompose*>(baseAt.get());

				Ptr<ASTOp> baseBlockAt = typedBaseAt->BlockImage.child();
                bool baseBlockHasAny = m_hasRuntimeParamVisitor.HasAny( baseBlockAt );
                if ( baseBlockHasAny )
                {
                    optimised = true;

                    // Swap
					Ptr<ASTOpImageCompose> childCompose = mu::Clone<ASTOpImageCompose>(at);
                    childCompose->Base = typedBaseAt->Base.child();

					Ptr<ASTOpImageCompose> parentCompose = mu::Clone<ASTOpImageCompose>(baseAt);
                    parentCompose->Base = childCompose;

                    at = parentCompose;
                }
            }


            // Try to optimise the block
            // This optimisation requires a lot of memory for every target. Use only if
            // we are optimising for GPU processing.
            if ( !optimised && blockHasRuntime && !baseHasRuntime
                 //&& m_stateProps.m_gpu.m_external
                 // TODO BLEH
                 // Only worth in case of more than one block using the same operation. Move this
                 // optimisation to that test.
                 //&& false
                 )
            {
                switch ( blockType )
                {
                case OP_TYPE::IM_LAYERCOLOUR:
                {
                    optimised = true;

					const ASTOpImageLayerColor* typedBlockAt = static_cast<const ASTOpImageLayerColor*>(blockAt.get());

					Ptr<ASTOp> blockImage = typedBlockAt->base.child();
					Ptr<ASTOp> blockMask = typedBlockAt->mask.child();

                    // The mask is a compose of the layer mask on a black image, however if there is
                    // no mask and the base of the layer opertation is a blanklayout, we can skip
                    // generating a mask.
                    Ptr<ASTOpImageCompose> maskOp;
                    if (blockMask || baseType!=OP_TYPE::IM_BLANKLAYOUT)
                    {
                        maskOp = mu::Clone<ASTOpImageCompose>(at);
						Ptr<ASTOp> newMaskBlock = EnsureValidMask(blockMask, blockImage);
                        maskOp->BlockImage = newMaskBlock;

                        Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                        blackOp->op.type = OP_TYPE::CO_CONSTANT;
                        blackOp->op.args.ColourConstant.value[0] = 0;
                        blackOp->op.args.ColourConstant.value[1] = 0;
                        blackOp->op.args.ColourConstant.value[2] = 0;
						blackOp->op.args.ColourConstant.value[3] = 1;

                        Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                        plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                        plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                        plainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE;
                        plainOp->op.args.ImagePlainColour.size[0] = 4;
						plainOp->op.args.ImagePlainColour.size[1] = 4;
						plainOp->op.args.ImagePlainColour.LODs = 1;

                        Ptr<ASTOpFixed> baseResizeOp = new ASTOpFixed;
                        baseResizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                        baseResizeOp->SetChild( baseResizeOp->op.args.ImageResizeLike.sizeSource, baseAt );
                        baseResizeOp->SetChild( baseResizeOp->op.args.ImageResizeLike.source, plainOp );

                        maskOp->Base = baseResizeOp;
                    }

                    // The base is composition of the layer base on the compose base
                    Ptr<ASTOpImageCompose> baseOp = mu::Clone<ASTOpImageCompose>(at);
                    baseOp->BlockImage = typedBlockAt->base.child();

                    Ptr<ASTOpImageLayerColor> nop = mu::Clone<ASTOpImageLayerColor>(blockAt);
                    nop->mask = maskOp;
                    nop->base = baseOp;

                    // Done
                    at = nop;
                    break;
                }

                case OP_TYPE::IM_LAYER:
                {
                    optimised = true;

                    const ASTOpImageLayer* typedBlockAt = static_cast<const ASTOpImageLayer*>(blockAt.get());

					Ptr<ASTOp> blockImage = typedBlockAt->base.child();
					Ptr<ASTOp> blockBlended = typedBlockAt->blend.child();
					Ptr<ASTOp> blockMask = typedBlockAt->mask.child();

                    // The mask is a compose of the layer mask on a black image, however if there is
                    // no mask and the base of the layer opertation is a blanklayout, we can skip
                    // generating a mask.
                    Ptr<ASTOpImageCompose> maskOp;
                    if (blockMask || baseType != OP_TYPE::IM_BLANKLAYOUT)
                    {
                        maskOp = mu::Clone<ASTOpImageCompose>(at);
						Ptr<ASTOp> newMaskBlock = EnsureValidMask(blockMask, blockImage);
                        maskOp->BlockImage = newMaskBlock;


                        Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                        blackOp->op.type = OP_TYPE::CO_CONSTANT;
                        blackOp->op.args.ColourConstant.value[0] = 0;
                        blackOp->op.args.ColourConstant.value[1] = 0;
                        blackOp->op.args.ColourConstant.value[2] = 0;
						blackOp->op.args.ColourConstant.value[3] = 1;

                        Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                        plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                        plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                        plainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE;
                        plainOp->op.args.ImagePlainColour.size[0] = 4;
						plainOp->op.args.ImagePlainColour.size[1] = 4;
						plainOp->op.args.ImagePlainColour.LODs = 1;

                        Ptr<ASTOpFixed> baseResizeOp = new ASTOpFixed;
                        baseResizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                        baseResizeOp->SetChild( baseResizeOp->op.args.ImageResizeLike.sizeSource, baseAt );
                        baseResizeOp->SetChild( baseResizeOp->op.args.ImageResizeLike.source, plainOp );

                        maskOp->Base = baseResizeOp;
                    }

                    // The blended is a compose of the blended image on a blank image
					Ptr<ASTOpImageCompose> blendedOp = mu::Clone<ASTOpImageCompose>(at);
                    {
                        blendedOp->BlockImage = blockBlended;

                        Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                        blackOp->op.type = OP_TYPE::CO_CONSTANT;
                        blackOp->op.args.ColourConstant.value[0] = 0;
                        blackOp->op.args.ColourConstant.value[1] = 0;
                        blackOp->op.args.ColourConstant.value[2] = 0;
						blackOp->op.args.ColourConstant.value[3] = 1;

                        Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                        plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                        plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                        FImageDesc blendedDesc = baseAt->GetImageDesc();
                        plainOp->op.args.ImagePlainColour.format = blendedDesc.m_format;
                        plainOp->op.args.ImagePlainColour.size[0] = 4;
						plainOp->op.args.ImagePlainColour.size[1] = 4;
						plainOp->op.args.ImagePlainColour.LODs = 1;

                        Ptr<ASTOpFixed> resizeOp = new ASTOpFixed;
                        resizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                        resizeOp->SetChild( resizeOp->op.args.ImageResizeLike.sizeSource, baseAt );
                        resizeOp->SetChild( resizeOp->op.args.ImageResizeLike.source, plainOp );

                        blendedOp->Base = resizeOp;
                    }

                    // The base is composition of the softlight base on the compose base
                    Ptr<ASTOpImageCompose> baseOp = mu::Clone<ASTOpImageCompose>(at);
                    baseOp->BlockImage = typedBlockAt->base.child();

                    Ptr<ASTOpImageLayer> nop = mu::Clone<ASTOpImageLayer>(blockAt);
                    nop->base = baseOp;
                    nop->mask = maskOp;
                    nop->blend = blendedOp;

                    // Done
                    at = nop;
                    break;
                }


//                case OP_TYPE::IM_INTERPOLATE:
//                {
//                    optimised = true;
//                    OP op = program.m_code[blockAt];

//                    // The targets are composition of the block targets on the compose base
//                    for ( int t=0; t<MUTABLE_OP_MAX_INTERPOLATE_COUNT; ++t )
//                    {
//                        if ( op.args.ImageInterpolate.targets[t] )
//                        {
//                            OP targetOp = program.m_code[at];
//                            targetOp.args.ImageCompose.blockImage =
//                                    op.args.ImageInterpolate.targets[t];
//                            op.args.ImageInterpolate.targets[t] = program.AddOp( targetOp );
//                        }
//                    }

//                    // Done
//                    at = program.AddOp( op );

//                    // Reprocess the new children
//                    at = Recurse( at, program );

//                    break;
//                }

                default:
                    break;

                }
            }


            // Try to optimise the base
            if ( !optimised && baseHasRuntime /*&& m_stateProps.nodeState.m_optimisation.m_gpu.m_external*/ )
            {
                switch ( baseType )
                {
                case OP_TYPE::IM_LAYERCOLOUR:
                {
                    optimised = true;

                    const ASTOpImageLayerColor* typedBaseAt = static_cast<const ASTOpImageLayerColor*>(baseAt.get());

					Ptr<ASTOpImageCompose> maskOp = mu::Clone<ASTOpImageCompose>(at);
                    {
                        Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                        blackOp->op.type = OP_TYPE::CO_CONSTANT;
                        blackOp->op.args.ColourConstant.value[0] = 0;
                        blackOp->op.args.ColourConstant.value[1] = 0;
                        blackOp->op.args.ColourConstant.value[2] = 0;
						blackOp->op.args.ColourConstant.value[3] = 1;

                        Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                        plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                        plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                        plainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE; //TODO: FORMAT_LIKE
                        plainOp->op.args.ImagePlainColour.size[0] = 4;
						plainOp->op.args.ImagePlainColour.size[1] = 4;
						plainOp->op.args.ImagePlainColour.LODs = 1;

                        Ptr<ASTOpFixed> blockResizeOp = new ASTOpFixed;
                        blockResizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                        blockResizeOp->SetChild( blockResizeOp->op.args.ImageResizeLike.sizeSource, blockAt );
                        blockResizeOp->SetChild( blockResizeOp->op.args.ImageResizeLike.source, plainOp );

                        // Blank out the block from the mask
						Ptr<ASTOp> newMaskBase = EnsureValidMask( typedBaseAt->mask.child(), baseAt );
                        maskOp->Base = newMaskBase;
                        maskOp->BlockImage = blockResizeOp;
                    }

                    // The base is composition of the softlight base on the compose base
					Ptr<ASTOpImageCompose> baseOp = mu::Clone<ASTOpImageCompose>(at);
                    baseOp->Base = typedBaseAt->base.child();

                    Ptr<ASTOpImageLayerColor> nop = mu::Clone<ASTOpImageLayerColor>(baseAt);
                    nop->base = baseOp;
                    nop->mask = maskOp;

                    // Done
                    at = nop;
                    break;
                }

                case OP_TYPE::IM_LAYER:
                {
                    optimised = true;

                    const ASTOpImageLayer* typedBaseAt = static_cast<const ASTOpImageLayer*>(baseAt.get());

					Ptr<ASTOpImageCompose> maskOp = mu::Clone<ASTOpImageCompose>(at);
                    {
                        Ptr<ASTOpFixed> blackOp = new ASTOpFixed;
                        blackOp->op.type = OP_TYPE::CO_CONSTANT;
                        blackOp->op.args.ColourConstant.value[0] = 0;
                        blackOp->op.args.ColourConstant.value[1] = 0;
                        blackOp->op.args.ColourConstant.value[2] = 0;
						blackOp->op.args.ColourConstant.value[3] = 1;

                        Ptr<ASTOpFixed> plainOp = new ASTOpFixed;
                        plainOp->op.type = OP_TYPE::IM_PLAINCOLOUR;
                        plainOp->SetChild( plainOp->op.args.ImagePlainColour.colour, blackOp );
                        plainOp->op.args.ImagePlainColour.format = EImageFormat::IF_L_UBYTE; //TODO: FORMAT_LIKE
                        plainOp->op.args.ImagePlainColour.size[0] = 4;
						plainOp->op.args.ImagePlainColour.size[1] = 4;
						plainOp->op.args.ImagePlainColour.LODs = 1;

                        Ptr<ASTOpFixed> blockResizeOp = new ASTOpFixed;
                        blockResizeOp->op.type = OP_TYPE::IM_RESIZELIKE;
                        blockResizeOp->SetChild( blockResizeOp->op.args.ImageResizeLike.sizeSource, blockAt );
                        blockResizeOp->SetChild( blockResizeOp->op.args.ImageResizeLike.source, plainOp );

                        // Blank out the block from the mask
                        Ptr<ASTOp> newMaskBase = EnsureValidMask( typedBaseAt->mask.child(), baseAt );
                        maskOp->Base = newMaskBase;
                        maskOp->BlockImage = blockResizeOp;
                    }

                    // The base is composition of the effect base on the compose base
                    Ptr<ASTOpImageCompose> baseOp = mu::Clone<ASTOpImageCompose>(at);
                    baseOp->Base = typedBaseAt->base.child();

                    Ptr<ASTOpImageLayer> nop = mu::Clone<ASTOpImageLayer>(baseAt);
                    nop->base = baseOp;
                    nop->mask = maskOp;

                    // Done
                    at = nop;
                    break;
                }


//                case OP_TYPE::IM_INTERPOLATE:
//                {
//                    optimised = true;
//                    OP op = program.m_code[baseAt];

//                    // The targets are composition of the blocks on the compose base targets
//                    for ( int t=0; t<MUTABLE_OP_MAX_INTERPOLATE_COUNT; ++t )
//                    {
//                        if ( op.args.ImageInterpolate.targets[t] )
//                        {
//                            OP targetOp = program.m_code[at];
//                            targetOp.args.ImageCompose.base =
//                                    op.args.ImageInterpolate.targets[t];
//                            op.args.ImageInterpolate.targets[t] = program.AddOp( targetOp );
//                        }
//                    }

//                    // Done
//                    at = program.AddOp( op );

//                    // Reprocess the new children
//                    at = Recurse( at, program );
//                    break;
//                }

                default:
                    break;

                }
            }


            m_modified = m_modified || optimised;
            break;
        }

/*
        //-----------------------------------------------------------------------------------------
        // TODO: Other ops?
        case OP_TYPE::IM_BLEND:
        {
            OP op = program.m_code[at];

            if ( !m_hasRuntimeParamVisitor.HasAny( op.args.ImageLayer.mask, program ) )
            {
                // If both the base and the blended have the same image layer operation with
                // similar parameters, we can move that operation up.
                OP_TYPE baseType = program.m_code[ op.args.ImageLayer.base ].type;
                OP_TYPE blendedType = program.m_code[ op.args.ImageLayer.blended ].type;
                if ( baseType == blendedType )
                {
                    switch ( baseType )
                    {
                    case OP_TYPE::IM_BLENDCOLOUR:
                    case OP_TYPE::IM_SOFTLIGHTCOLOUR:
                    case OP_TYPE::IM_HARDLIGHTCOLOUR:
                    case OP_TYPE::IM_BURNCOLOUR:
                    case OP_TYPE::IM_SCREENCOLOUR:
                    case OP_TYPE::IM_OVERLAYCOLOUR:
                    case OP_TYPE::IM_DODGECOLOUR:
                    case OP_TYPE::IM_MULTIPLYCOLOUR:
                    {
                        if ( OptimisationOptions.m_optimiseOverlappedMasks )
                        {
                            OP::ADDRESS maskAt = op.args.ImageLayer.mask;
                            OP::ADDRESS baseMaskAt =
                                    program.m_code[ op.args.ImageLayer.base ].args.ImageLayerColour.mask;
                            OP::ADDRESS blendedMaskAt =
                                    program.m_code[ op.args.ImageLayer.blended ].args.ImageLayerColour.mask;
                            OP::ADDRESS baseColourAt =
                                    program.m_code[ op.args.ImageLayer.base ].args.ImageLayerColour.colour;
                            OP::ADDRESS blendedColourAt =
                                    program.m_code[ op.args.ImageLayer.blended ].args.ImageLayerColour.colour;

                            // Check extra conditions on the masks
                            if ( maskAt && baseMaskAt && blendedMaskAt
                                 && (baseColourAt==blendedColourAt)
                                 && !AreMasksOverlapping( program, baseMaskAt, blendedMaskAt )
                                 && !AreMasksOverlapping( program, baseMaskAt, maskAt ) )
                            {
                                // We can apply the transform
                                m_modified = true;

                                OP baseOp;
                                baseOp.type = OP_TYPE::IM_BLEND;
                                baseOp.args.ImageLayer.base =
                                        program.m_code[ op.args.ImageLayer.base ].args.ImageLayerColour.base;
                                baseOp.args.ImageLayer.blended =
                                        program.m_code[ op.args.ImageLayer.blended ].args.ImageLayerColour.base;
                                baseOp.args.ImageLayer.mask = maskAt;

                                // TODO: Find out why these are not equivalent
    //							OP maskOp;
    //							maskOp.type = OP_TYPE::IM_SCREEN;
    //							maskOp.args.ImageLayer.base = baseMaskAt;
    //							maskOp.args.ImageLayer.blended = blendedMaskAt;
                                OP maskOp;
                                maskOp.type = OP_TYPE::IM_BLEND;
                                maskOp.args.ImageLayer.base = baseMaskAt;
                                maskOp.args.ImageLayer.blended = blendedMaskAt;
                                maskOp.args.ImageLayer.mask = blendedMaskAt;
                                maskOp.args.ImageLayer.flags = OP::ImageLayerArgs::F_BINARY_MASK;

                                OP top;
                                top.type = baseType;
                                top.args.ImageLayerColour.base = program.AddOp( baseOp );
                                top.args.ImageLayerColour.mask = program.AddOp( maskOp );
                                top.args.ImageLayerColour.colour = baseColourAt;
                                at = program.AddOp( top );
                            }
                        }

                        break;
                    }

                    default:
                        break;

                    }
                }
            }
            break;
        }

        */

        //-----------------------------------------------------------------------------------------
        // Sink the mipmap if worth it.
        case OP_TYPE::IM_MIPMAP:
        {
			const ASTOpImageMipmap* typedAt = static_cast<const ASTOpImageMipmap*>(at.get());

			Ptr<ASTOp> sourceOp = typedAt->Source.child();

            switch ( sourceOp->GetOpType() )
            {
            case OP_TYPE::IM_LAYERCOLOUR:
            {
                const ASTOpImageLayerColor* typedSource = static_cast<const ASTOpImageLayerColor*>(sourceOp.get());

                bool colourHasRuntime = m_hasRuntimeParamVisitor.HasAny( typedSource->color.child() );

                if (colourHasRuntime)
                {
                    m_modified = true;

					Ptr<ASTOpImageLayerColor> top = mu::Clone<ASTOpImageLayerColor>(sourceOp);

					Ptr<ASTOpImageMipmap> baseOp = mu::Clone<ASTOpImageMipmap>(at);
                    baseOp->Source = typedSource->base.child();
                    top->base = baseOp;

					Ptr<ASTOp> sourceMaskOp = typedSource->mask.child();
                    if (sourceMaskOp)
                    {
						Ptr<ASTOpImageMipmap> maskOp = mu::Clone<ASTOpImageMipmap>(at);
                        maskOp->Source = sourceMaskOp;
                        top->mask = maskOp;
                    }

                    at = top;
                }

                break;
            }

            default:
                break;
            }

            break;
        }

        default:
            break;

        }

        return at;
    }


    class AccumulateAllImageFormatsOpAST
            : public Visitor_TopDown_Unique_Const< std::array<uint8_t, size_t(EImageFormat::IF_COUNT)> >
    {
    public:

        void Run( const ASTOpList& roots )
        {
            MUTABLE_CPUPROFILER_SCOPE(AccumulateAllImageFormatsOpAST);

            // Initially, all formats are supported
            m_allSupported.fill(1);

            // The initial traversal state is no format supported
            m_initialState.fill(0);
            Traverse( roots, m_initialState );
        }


        bool Visit( const Ptr<ASTOp>& at ) override
        {
            bool recurse = false;

            const std::array<uint8_t, (size_t)EImageFormat::IF_COUNT>& currentFormats = GetCurrentState();

            // Remove unsupported formats
            if (GetOpDataType( at->GetOpType() )==DT_IMAGE)
            {
				std::array<uint8_t, (size_t)EImageFormat::IF_COUNT>* it = m_supportedFormats.Find(at);
                if (!it)
                {
                    // Default to all supported
                    m_supportedFormats.Add(at, m_allSupported);
                    it = m_supportedFormats.Find(at);
                }

                for ( unsigned f=0; f< (unsigned)EImageFormat::IF_COUNT; ++f )
                {
                    if ( !currentFormats[f] )
                    {
                        (*it)[f] = 0;
                    }
                }
            }

            switch ( at->GetOpType() )
            {
            // TODO: Code shared with the constant data format optimisation visitor
            case OP_TYPE::IM_LAYERCOLOUR:
            {
                const ASTOpImageLayerColor* typedAt = static_cast<const ASTOpImageLayerColor*>(at.get());

                RecurseWithCurrentState( typedAt->base.child() );
                RecurseWithCurrentState( typedAt->color.child() );

                if ( typedAt->mask )
                {
                    std::array<uint8_t, (size_t)EImageFormat::IF_COUNT> newState;
                    newState.fill(0);
                    newState[(size_t)EImageFormat::IF_L_UBYTE ] = 1;
                    newState[(size_t)EImageFormat::IF_L_UBYTE_RLE ] = 1;

                    RecurseWithState( typedAt->mask.child(), newState );
                }
                break;
            }

            case OP_TYPE::IM_LAYER:
            {
                const ASTOpImageLayer* typedAt = static_cast<const ASTOpImageLayer*>(at.get());

                RecurseWithCurrentState( typedAt->base.child() );
                RecurseWithCurrentState( typedAt->blend.child() );

                std::array<uint8_t, (size_t)EImageFormat::IF_COUNT> newState;
                newState.fill(0);
                // TODO
                //newState[ IF_L_UBYTE ] = 1;
                //newState[ IF_L_UBYTE_RLE ] = 1;

                if ( typedAt->mask )
                {
                    RecurseWithState( typedAt->mask.child(), newState );
                }
                break;
            }

            case OP_TYPE::IM_DISPLACE:
            {
				const ASTOpFixed* typedAt = static_cast<const ASTOpFixed*>(at.get());

                RecurseWithCurrentState( typedAt->children[typedAt->op.args.ImageDisplace.source].child() );

                std::array<uint8_t, (size_t)EImageFormat::IF_COUNT> newState;
                newState.fill(0);
                newState[(size_t)EImageFormat::IF_L_UBYTE ] = 1;
                newState[(size_t)EImageFormat::IF_L_UBYTE_RLE ] = 1;
                RecurseWithState( typedAt->children[typedAt->op.args.ImageDisplace.displacementMap].child(), newState );
                break;
            }

            default:
                SetCurrentState( m_initialState );
                recurse = true;
                break;
            }

            return recurse;
        }


        bool IsSupportedFormat( Ptr<ASTOp> at, EImageFormat format ) const
        {
            const std::array<uint8_t, (size_t)EImageFormat::IF_COUNT>* it = m_supportedFormats.Find(at);
            if (!it)
            {
                return false;
            }

            return (*it)[(size_t)format]!=0;
        }


    private:

        //! Formats known to be supported for every instruction.
        //! IF_COUNT*code.size() entries
        TMap< Ptr<ASTOp>, std::array<uint8_t, (size_t)EImageFormat::IF_COUNT> > m_supportedFormats;

        //! Constant convenience initial value
        std::array<uint8_t, (size_t)EImageFormat::IF_COUNT> m_initialState;

        //! Constant convenience initial value
        std::array<uint8_t, (size_t)EImageFormat::IF_COUNT> m_allSupported;

    };


    //---------------------------------------------------------------------------------------------
    void SubtreeRelevantParametersVisitorAST::Run( Ptr<ASTOp> root )
    {
        // Cached?
		TSet<FString>* it = m_resultCache.Find( FState(root,false) );
        if (it)
        {
            m_params = *it;
            return;
        }

        // Not cached
        {
            MUTABLE_CPUPROFILER_SCOPE(SubtreeRelevantParametersVisitorAST);

            m_params.Empty();

            // The state is the onlyLayoutRelevant flag
            ASTOp::Traverse_TopDown_Unique_Imprecise_WithState<bool>( root, false,
                [&]( Ptr<ASTOp>& at, bool& state, TArray<TPair<Ptr<ASTOp>,bool>>& pending )
            {
                (void)state;

                switch ( at->GetOpType() )
                {
                case OP_TYPE::NU_PARAMETER:
                case OP_TYPE::SC_PARAMETER:
                case OP_TYPE::BO_PARAMETER:
                case OP_TYPE::CO_PARAMETER:
                case OP_TYPE::PR_PARAMETER:
                case OP_TYPE::IM_PARAMETER:
                {
					const ASTOpParameter* typedAt = static_cast<const ASTOpParameter*>(at.get());
                    m_params.Add(typedAt->parameter.m_name);

                    // Not interested in the parameters from the parameters decorators.
                    return false;

                    break;
                }

				case OP_TYPE::LA_FROMMESH:
				{
					// Manually choose how to recurse this op
					const ASTOpLayoutFromMesh* pTyped = static_cast<const ASTOpLayoutFromMesh*>(at.get());

					// For that mesh we only want to know about the layouts
					if (const ASTChild& Mesh = pTyped->Mesh)
					{
						pending.Add({ Mesh.m_child, true });
					}

					return false;
				}

                case OP_TYPE::ME_MORPH:
                {
                    // Manually choose how to recurse this op
					const ASTOpMeshMorph* pTyped = static_cast<const ASTOpMeshMorph*>( at.get() );

                    if ( pTyped->Base )
                    {
						pending.Add({ pTyped->Base.m_child, state });
                    }

                    // Mesh morphs don't modify the layouts, so we can ignore the factor and morphs
                    if (!state)
                    {
                        if ( pTyped->Factor )
                        {
							pending.Add({ pTyped->Factor.m_child, state });
                        }

                        if ( pTyped->Target )
                        {
							pending.Add({ pTyped->Target.m_child, state });
                        }
                    }

                    return false;
                }

                default:
                    break;
                }

                return true;
            });

            m_resultCache.Add( FState(root,false), m_params );
        }
    }


    //---------------------------------------------------------------------------------------------
    //! Mark all the instructions that don't depend on runtime parameters but are below
    //! instructions that do.
    //! Also detect which instructions are the root of a resource that is dynamic in this state.
    //! Visitor state is:
    //!   .first IsResourceRoot
    //!   .second ParentIsRuntime
    //---------------------------------------------------------------------------------------------
    class StateCacheDetectorAST : public Visitor_TopDown_Unique_Const< TPair<bool,bool> >
    {
    public:

        StateCacheDetectorAST(FStateCompilationData* pState )
            : m_hasRuntimeParamVisitor( pState )
        {
            ASTOpList roots;
            roots.Add(pState->root);
			Traverse(roots, { false,false });

            pState->m_updateCache.Empty();
            pState->m_dynamicResources.Empty();

            for( const TPair<Ptr<ASTOp>, bool>& i : m_cache )
            {
                if ( i.Value )
                {
                    pState->m_updateCache.Add( i.Key );
                }
            }

            for(const TPair<Ptr<ASTOp>, bool>& i : m_dynamicResourceRoot )
            {
                if ( i.Value )
                {
                    // Generate the list of relevant parameters
                    SubtreeRelevantParametersVisitorAST subtreeParams;
                    subtreeParams.Run( i.Key );

					// Temp copy
					TArray<FString> ParamCopy;
					for ( const FString& e: subtreeParams.m_params )
					{
						ParamCopy.Add(e);
					}

                    pState->m_dynamicResources.Emplace( i.Key, MoveTemp(ParamCopy) );
                }
            }
        }


        bool Visit( const Ptr<ASTOp>& at ) override
        {
            bool thisIsRuntime = m_hasRuntimeParamVisitor.HasAny( at );

            bool resourceRoot = GetCurrentState().Key;
            bool parentIsRuntime = GetCurrentState().Value;

			m_cache.FindOrAdd(at, false);

            OP_TYPE type = at->GetOpType();
            if ( GetOpDesc( type ).cached )
            {
                // If parent is runtime, but we are not
                if ( (!thisIsRuntime) && parentIsRuntime
                     &&
                     // Resource roots are special, and they don't need to be marked as updateCache
                     // since the dynamicResource flag takes care of everything.
                     !resourceRoot )
                {
                    // We want to cache this result to update the instances.
                    // Mark this as update cache
                    m_cache.Add(at, true);
                }
            }

            if ( !m_cache[at] && resourceRoot && thisIsRuntime )
            {
                m_dynamicResourceRoot.Add(at, true);
            }

            if ( !m_cache[at] && thisIsRuntime )
            {
                switch( type )
                {
                case OP_TYPE::IN_ADDIMAGE:
                case OP_TYPE::IN_ADDMESH:
                case OP_TYPE::IN_ADDVECTOR:
                case OP_TYPE::IN_ADDSCALAR:
                case OP_TYPE::IN_ADDSTRING:
                {
					const ASTOpInstanceAdd* typedAt = static_cast<const ASTOpInstanceAdd*>(at.get());

                    TPair<bool,bool> newState;
                    newState.Key = false; //resource root
                    newState.Value = thisIsRuntime;
                    RecurseWithState( typedAt->instance.child(), newState );

                    if ( typedAt->value )
                    {
                        newState.Key = true; //resource root
                        newState.Value = thisIsRuntime;
                        RecurseWithState( typedAt->value.child(), newState );
                    }
                    return false;
                }

                default:
                {
                    TPair<bool,bool> newState;
                    newState.Key = false; //resource root
                    newState.Value = thisIsRuntime;
                    SetCurrentState(newState);
                    return true;
                }

                }
            }

            return false;
        }

    private:

        //!
        TMap<Ptr<ASTOp>,bool> m_cache;
		TMap<Ptr<ASTOp>,bool> m_dynamicResourceRoot;

        RuntimeParameterVisitorAST m_hasRuntimeParamVisitor;
    };


    //---------------------------------------------------------------------------------------------
    //! Find out what images can be compressed during build phase of an instance so that the update
    //! cache can be smaller (and some update operations faster)
    //---------------------------------------------------------------------------------------------
    class StateCacheFormatOptimiserAST : public Visitor_TopDown_Unique_Cloning
    {
    public:

        StateCacheFormatOptimiserAST(FStateCompilationData& state,
                                   const AccumulateAllImageFormatsOpAST& opFormats )
            : m_state(state)
            , m_opFormats(opFormats)
        {
            Traverse( state.root );
        }


    protected:

        Ptr<ASTOp> Visit( Ptr<ASTOp> at, bool& processChildren ) override
        {
            processChildren = true;

            bool isUpdateCache = m_state.m_updateCache.Contains(at);

            if ( isUpdateCache )
            {
                // Its children cannot be update-cache, so no need to process them.
                processChildren = false;

                // See if we can convert it to a more efficient format
                if ( GetOpDataType( at->GetOpType() )==DT_IMAGE )
                {
                    FImageDesc desc = at->GetImageDesc();

                    if ( desc.m_format!=EImageFormat::IF_L_UBYTE_RLE
                         &&
                         m_opFormats.IsSupportedFormat(at, EImageFormat::IF_L_UBYTE_RLE) )
                    {
                        Ptr<ASTOpImagePixelFormat> op = new ASTOpImagePixelFormat;
                        op->Format = EImageFormat::IF_L_UBYTE_RLE;
                        // Note: we have to clone here, to avoid a loop with the visitor system
                        // that updates visited children before processing a node.
						ASTOp::MapChildFunc Identity = [](const Ptr<ASTOp>& o) {return o;};
						op->Source = at->Clone(Identity);

                        at = op;
                    }
                }

            }

            return at;
        }

    private:

		FStateCompilationData& m_state;

        const AccumulateAllImageFormatsOpAST& m_opFormats;
    };


    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    RuntimeTextureCompressionRemoverAST::RuntimeTextureCompressionRemoverAST(
		FStateCompilationData* pState,
		bool bInAlwaysUncompress
	)
        : m_hasRuntimeParamVisitor(pState)
		, bAlwaysUncompress(bInAlwaysUncompress)
    {
        Traverse( pState->root );
    }


    Ptr<ASTOp> RuntimeTextureCompressionRemoverAST::Visit( Ptr<ASTOp> at, bool& processChildren )
    {
        OP_TYPE type = at->GetOpType();
        processChildren = GetOpDataType(type)==DT_INSTANCE;

        // TODO: Finer grained: what if the runtime parameter just selects between compressed
        // textures? We don't want them uncompressed.
        if( type==OP_TYPE::IN_ADDIMAGE )
        {
			ASTOpInstanceAdd* typedAt = static_cast<ASTOpInstanceAdd*>(at.get());
			Ptr<ASTOp> imageAt = typedAt->value.child();

            // Does it have a runtime parameter in its subtree?
            bool hasRuntimeParameter = m_hasRuntimeParamVisitor.HasAny( imageAt );

            if (bAlwaysUncompress || hasRuntimeParameter)
            {
                FImageDesc imageDesc = imageAt->GetImageDesc( true );

                // Is it a compressed format?
				EImageFormat format = imageDesc.m_format;
				EImageFormat uncompressedFormat = GetUncompressedFormat( format );
                bool isCompressedFormat = (uncompressedFormat != format);

                if (isCompressedFormat)
                {
                    Ptr<ASTOpInstanceAdd> newAt = mu::Clone<ASTOpInstanceAdd>(at);

                    // Add a new format operation to uncompress the image
                    Ptr<ASTOpImagePixelFormat> fop = new ASTOpImagePixelFormat;
                    fop->Format = uncompressedFormat;
                    fop->FormatIfAlpha = uncompressedFormat;
                    fop->Source = imageAt;

                    newAt->value = fop;
                    at = newAt;
                }
            }
        }

        return at;
    }


    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    LODCountReducerAST::LODCountReducerAST( Ptr<ASTOp>& root, int32 lodCount )
    {
        m_lodCount = lodCount;
        Traverse( root );
    }


    Ptr<ASTOp> LODCountReducerAST::Visit( Ptr<ASTOp> at, bool& processChildren )
    {
        processChildren = true;

        if( at->GetOpType()==OP_TYPE::IN_ADDLOD )
        {
			ASTOpAddLOD* typedAt = static_cast<ASTOpAddLOD*>(at.get());

            if (typedAt->lods.Num()>(size_t)m_lodCount)
            {
                Ptr<ASTOpAddLOD> newAt = mu::Clone<ASTOpAddLOD>(at);
                while( newAt->lods.Num()>(size_t)m_lodCount )
                {
                    newAt->lods.Pop();
                }
                at = newAt;
            }

            processChildren = false;
        }

        return at;
    }


    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    //---------------------------------------------------------------------------------------------
    void CodeOptimiser::OptimiseStatesAST()
    {
		MUTABLE_CPUPROFILER_SCOPE(OptimiseStatesAST);

		for ( int32 s=0; s<m_states.Num(); ++s )
		{
			// Remove the unnecessary lods
			FStateOptimizationOptions StateOptimization = m_states[s].nodeState.Optimisation;
			if (StateOptimization.bOnlyFirstLOD)
			{
				LODCountReducerAST(m_states[s].root, StateOptimization.FirstLOD + 1 + StateOptimization.NumExtraLODsToBuildAfterFirstLOD);
			}

			// Apply texture compression strategy
			bool bModified = false;
			switch (StateOptimization.TextureCompressionStrategy)
			{
			case ETextureCompressionStrategy::DontCompressRuntime:
			{
				MUTABLE_CPUPROFILER_SCOPE(RuntimeTextureCompressionRemover);
				RuntimeTextureCompressionRemoverAST r(&m_states[s], false);
				bModified = true;
				break;
			}

			case ETextureCompressionStrategy::NeverCompress:
			{
				MUTABLE_CPUPROFILER_SCOPE(RuntimeTextureCompressionRemover);
				RuntimeTextureCompressionRemoverAST r(&m_states[s], true);
				bModified = true;
				break;
			}

			default:
				break;
			}

            // If a state has no runtime parameters, skip its optimisation alltogether
            if (bModified || m_states[s].nodeState.RuntimeParams.Num())
            {
                // Promote the intructions that depend on runtime parameters, and sink new
                // format instructions.
                bool modified = true;
                int32 numIterations = 0;
                while (modified && (!m_optimizeIterationsMax || m_optimizeIterationsLeft>0 || !numIterations ))
                {
                    modified = false;

                    ++numIterations;
                    --m_optimizeIterationsLeft;
                    UE_LOG(LogMutableCore, Verbose, TEXT("State optimise iteration %d, max %d, left %d"),
                            numIterations, m_optimizeIterationsMax, m_optimizeIterationsLeft);

                    UE_LOG(LogMutableCore, Verbose, TEXT(" - before parameter optimiser"));

                    ParameterOptimiserAST param( m_states[s], m_options->GetPrivate()->OptimisationOptions );
                    modified = param.Apply();

                    TArray<Ptr<ASTOp>> roots;
                    roots.Add(m_states[s].root);

                    UE_LOG(LogMutableCore, Verbose, TEXT(" - after parameter optimiser"));
					//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

                    // All kind of optimisations that depend on the meaning of each operation
                    UE_LOG(LogMutableCore, Verbose, TEXT(" - semantic optimiser"));
                    modified |= SemanticOptimiserAST( roots, m_options->GetPrivate()->OptimisationOptions, 1 );
					//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));
					//ASTOp::LogHistogram(roots);

                    UE_LOG(LogMutableCore, Verbose, TEXT(" - sink optimiser"));
                    modified |= SinkOptimiserAST( roots, m_options->GetPrivate()->OptimisationOptions );
					//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));
					//ASTOp::LogHistogram(roots);

                    // Image size operations are treated separately
                    UE_LOG(LogMutableCore, Verbose, TEXT(" - size optimiser"));
                    modified |= SizeOptimiserAST( roots );
					//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

                    //LogicOptimiser log;
                    //modified |= log.Apply( program, s );
                }

                TArray<Ptr<ASTOp>> roots;
                roots.Add(m_states[s].root);

                UE_LOG(LogMutableCore, Verbose, TEXT(" - duplicated data remover"));
                DuplicatedDataRemoverAST( roots );
				//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

                UE_LOG(LogMutableCore, Verbose, TEXT(" - duplicated code remover"));
                DuplicatedCodeRemoverAST( roots );
				//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

                m_states[s].root = roots[0];
            }
        }


		TArray<Ptr<ASTOp>> roots;
		for (const FStateCompilationData& s : m_states)
		{
			roots.Add(s.root);
		}

        // Mark the instructions that don't depend on runtime parameters to be cached. This is
        // necessary at this stage before GPU optimisation.
        {
            AccumulateAllImageFormatsOpAST opFormats;
            opFormats.Run(roots);

			// Reset the state root operations in case they have changed due to optimization
			for (int32 RootIndex = 0; RootIndex < m_states.Num(); ++RootIndex)
			{
				m_states[RootIndex].root = roots[RootIndex];
			}

            for (FStateCompilationData& s: m_states )
            {
                {
                    UE_LOG(LogMutableCore, Verbose, TEXT(" - state cache"));
                    MUTABLE_CPUPROFILER_SCOPE(StateCache);
                    StateCacheDetectorAST c( &s );
                }

                {
                    UE_LOG(LogMutableCore, Verbose, TEXT(" - state cache format"));
                    MUTABLE_CPUPROFILER_SCOPE(StateCacheFormat);
                    StateCacheFormatOptimiserAST f( s, opFormats );
                }
            }
        }

        // Reoptimise because of state cache reformats and gpuization
        {
            MUTABLE_CPUPROFILER_SCOPE(Reoptimise);
            bool modified = true;
            int32 numIterations = 0;
			int32 Pass = 1;
            while (modified && (!m_optimizeIterationsMax || m_optimizeIterationsLeft>0 || !numIterations ))
            {
                ++numIterations;
                --m_optimizeIterationsLeft;
                UE_LOG(LogMutableCore, Verbose, TEXT("State reoptimise iteration %d, max %d, left %d"),
                        numIterations, m_optimizeIterationsMax, m_optimizeIterationsLeft);

                modified = false;

                UE_LOG(LogMutableCore, Verbose, TEXT(" - semantic optimiser"));
                modified |= SemanticOptimiserAST( roots, m_options->GetPrivate()->OptimisationOptions, Pass );
				//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

                // Image size operations are treated separately
                UE_LOG(LogMutableCore, Verbose, TEXT(" - size optimiser"));
                modified |= SizeOptimiserAST( roots );
				//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));
			}

            for(Ptr<ASTOp>& Root : roots)
            {
                UE_LOG(LogMutableCore, Verbose, TEXT(" - constant optimiser"));
				modified = ConstantGeneratorAST( m_options->GetPrivate(), Root, Pass );
			}

			//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

            UE_LOG(LogMutableCore, Verbose, TEXT(" - duplicated data remover"));
            DuplicatedDataRemoverAST( roots );
			//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));

            UE_LOG(LogMutableCore, Verbose, TEXT(" - duplicated code remover"));
            DuplicatedCodeRemoverAST( roots );
			//UE_LOG(LogMutableCore, Verbose, TEXT("(int) %s : %ld"), TEXT("ast size"), int64(ASTOp::CountNodes(roots)));
		}

		// Reset the state root operations in case they have changed due to optimization
		for (int32 RootIndex = 0; RootIndex < m_states.Num(); ++RootIndex)
		{
			m_states[RootIndex].root = roots[RootIndex];
		}

        // Optimise the data formats
        {
            MUTABLE_CPUPROFILER_SCOPE(DataFormats);

            DataOptimise( m_options.get(), roots);

            // After optimising the data formats, we may remove more constants
            DuplicatedDataRemoverAST( roots );
            DuplicatedCodeRemoverAST( roots );

            // Update the marks for the instructions that don't depend on runtime parameters to be
            // cached.
            for (FStateCompilationData& s:m_states)
            {
                StateCacheDetectorAST c( &s );
            }
        }

    }


}