/*===================== 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,
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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 ==================================*/
#include "Compiler/CISACodeGen/GeometryShaderCodeGen.hpp"

#include "Compiler/CISACodeGen/messageEncoding.hpp"
#include "Compiler/CISACodeGen/EmitVISAPass.hpp"
#include "Compiler/CISACodeGen/CollectGeometryShaderProperties.hpp"

#include "common/Types.hpp"
#include "common/debug/Debug.hpp"
#include "common/secure_mem.h"

#include <iStdLib/utility.h>

#include "common/LLVMWarningsPush.hpp"
#include <llvm/PassAnalysisSupport.h>
#include <llvm/Analysis/PostDominators.h>
#include "common/LLVMWarningsPop.hpp"

using namespace llvm;

/***********************************************************************************
Geometry Shader CodeGen
************************************************************************************/
namespace IGC
{
bool CGeometryShader::DiscardAdjacency(USC::GSHADER_INPUT_PRIMITIVE_TYPE inpPrimType)
{
    bool discAdj = false;
    switch(inpPrimType)
    {
    case USC::GSHADER_INPUT_POINT:
    case USC::GSHADER_INPUT_PATCHLIST_1:
    case USC::GSHADER_INPUT_PATCHLIST_2:
    case USC::GSHADER_INPUT_PATCHLIST_3:
    case USC::GSHADER_INPUT_PATCHLIST_4:
    case USC::GSHADER_INPUT_PATCHLIST_5:
    case USC::GSHADER_INPUT_PATCHLIST_6:
    case USC::GSHADER_INPUT_PATCHLIST_7:
    case USC::GSHADER_INPUT_PATCHLIST_8:
    case USC::GSHADER_INPUT_PATCHLIST_9:
    case USC::GSHADER_INPUT_PATCHLIST_10:
    case USC::GSHADER_INPUT_PATCHLIST_11:
    case USC::GSHADER_INPUT_PATCHLIST_12:
    case USC::GSHADER_INPUT_PATCHLIST_13:
    case USC::GSHADER_INPUT_PATCHLIST_14:
    case USC::GSHADER_INPUT_PATCHLIST_15:
    case USC::GSHADER_INPUT_PATCHLIST_16:
    case USC::GSHADER_INPUT_PATCHLIST_17:
    case USC::GSHADER_INPUT_PATCHLIST_18:
    case USC::GSHADER_INPUT_PATCHLIST_19:
    case USC::GSHADER_INPUT_PATCHLIST_20:
    case USC::GSHADER_INPUT_PATCHLIST_21:
    case USC::GSHADER_INPUT_PATCHLIST_22:
    case USC::GSHADER_INPUT_PATCHLIST_23:
    case USC::GSHADER_INPUT_PATCHLIST_24:
    case USC::GSHADER_INPUT_PATCHLIST_25:
    case USC::GSHADER_INPUT_PATCHLIST_26:
    case USC::GSHADER_INPUT_PATCHLIST_27:
    case USC::GSHADER_INPUT_PATCHLIST_28:
    case USC::GSHADER_INPUT_PATCHLIST_29:
    case USC::GSHADER_INPUT_PATCHLIST_30:
    case USC::GSHADER_INPUT_PATCHLIST_31:
    case USC::GSHADER_INPUT_PATCHLIST_32:
    case USC::GSHADER_INPUT_LINE_ADJ:
    case USC::GSHADER_INPUT_TRIANGLE_ADJ:
        discAdj = false;
        break;
    case USC::GSHADER_INPUT_LINE:
    case USC::GSHADER_INPUT_TRIANGLE:
    case USC::GSHADER_INPUT_RECTANGLE:
    case USC::GSHADER_INPUT_QUAD:
        discAdj = true;
        break;
    default:
        // !! unsupported input primitive type
        assert(0 && "Unimplemented Primitive type");
        break;
    }

    return discAdj;
}

/// Returns the number of vertices each primitive type consists of.
uint CGeometryShader::GetInputPrimitiveVertexCount(USC::GSHADER_INPUT_PRIMITIVE_TYPE inpPrimType)
{
    switch(inpPrimType)
    {
    case USC::GSHADER_INPUT_POINT        : return 1;
    case USC::GSHADER_INPUT_LINE         : return 2;
    case USC::GSHADER_INPUT_LINE_ADJ     : return 4;
    case USC::GSHADER_INPUT_TRIANGLE     : return 3;
    case USC::GSHADER_INPUT_TRIANGLE_ADJ : return 6;

    case USC::GSHADER_INPUT_PATCHLIST_1  : return 1;
    case USC::GSHADER_INPUT_PATCHLIST_2  : return 2;
    case USC::GSHADER_INPUT_PATCHLIST_3  : return 3;
    case USC::GSHADER_INPUT_PATCHLIST_4  : return 4;
    case USC::GSHADER_INPUT_PATCHLIST_5  : return 5;
    case USC::GSHADER_INPUT_PATCHLIST_6  : return 6;
    case USC::GSHADER_INPUT_PATCHLIST_7  : return 7;
    case USC::GSHADER_INPUT_PATCHLIST_8  : return 8;
    case USC::GSHADER_INPUT_PATCHLIST_9  : return 9;
    case USC::GSHADER_INPUT_PATCHLIST_10 : return 10;
    case USC::GSHADER_INPUT_PATCHLIST_11 : return 11;
    case USC::GSHADER_INPUT_PATCHLIST_12 : return 12;
    case USC::GSHADER_INPUT_PATCHLIST_13 : return 13;
    case USC::GSHADER_INPUT_PATCHLIST_14 : return 14;
    case USC::GSHADER_INPUT_PATCHLIST_15 : return 15;
    case USC::GSHADER_INPUT_PATCHLIST_16 : return 16;
    case USC::GSHADER_INPUT_PATCHLIST_17 : return 17;
    case USC::GSHADER_INPUT_PATCHLIST_18 : return 18;
    case USC::GSHADER_INPUT_PATCHLIST_19 : return 19;
    case USC::GSHADER_INPUT_PATCHLIST_20 : return 20;
    case USC::GSHADER_INPUT_PATCHLIST_21 : return 21;
    case USC::GSHADER_INPUT_PATCHLIST_22 : return 22;
    case USC::GSHADER_INPUT_PATCHLIST_23 : return 23;
    case USC::GSHADER_INPUT_PATCHLIST_24 : return 24;
    case USC::GSHADER_INPUT_PATCHLIST_25 : return 25;
    case USC::GSHADER_INPUT_PATCHLIST_26 : return 26;
    case USC::GSHADER_INPUT_PATCHLIST_27 : return 27;
    case USC::GSHADER_INPUT_PATCHLIST_28 : return 28;
    case USC::GSHADER_INPUT_PATCHLIST_29 : return 29;
    case USC::GSHADER_INPUT_PATCHLIST_30 : return 30;
    case USC::GSHADER_INPUT_PATCHLIST_31 : return 31;
    case USC::GSHADER_INPUT_PATCHLIST_32 : return 32;
    
    default:
        assert(0 && "Input primitive type not implemented");
        return 0;
    }
}

CGeometryShader::CGeometryShader(llvm::Function *pFunc, CShaderProgram* pProgram)
    : CShader(pFunc, pProgram)
    , m_pURBReadHandlesReg(nullptr)
    , m_pInstanceID(nullptr)
    , m_pURBWriteHandleReg(nullptr)
    , m_pPrimitiveID(nullptr)
{
}

CGeometryShader::~CGeometryShader()
{
}

CVariable* CGeometryShader::GetPrimitiveID()
{
    if (m_pPrimitiveID == nullptr)
    {
        m_pPrimitiveID = GetNewVariable(numLanes(m_SIMDSize), ISA_TYPE_D, EALIGN_GRF);
    }

    return m_pPrimitiveID;
}

CVariable* CGeometryShader::GetInstanceID()
{
    return m_pInstanceID;
}

/// Allocates a new variable that keeps input vertex URB handles.
/// The size of the variable depends on the number of vertices of the input primitive:
/// from one for point list to six for triangle with adjacency since each vertex
/// has a separate URB handle and they are placed one after another as part of the payload.
CVariable* CGeometryShader::GetURBReadHandlesReg()
{
    if (m_pURBReadHandlesReg == nullptr)
    {
        if(m_properties.Input().HasInstancing())
        {
            m_pURBReadHandlesReg = GetNewVariable(
                (uint16_t)m_properties.Input().VertexCount(),
                ISA_TYPE_UD,
                EALIGN_GRF,
                true);
        }
        else
        {
            m_pURBReadHandlesReg = GetNewVariable(
                numLanes(m_SIMDSize) * m_properties.Input().VertexCount(),
                ISA_TYPE_UD,
                EALIGN_GRF);
        }
    }
    return m_pURBReadHandlesReg;
}

CVariable* CGeometryShader::GetURBOutputHandle()
{
    return m_pURBWriteHandleReg;
}

/// Returns a variable that has the right URB read handle register.
/// Note that for GS we have as many urb read handles as vertices in input primitive
/// and we can address them indirectly.
CVariable* CGeometryShader::GetURBInputHandle(CVariable* pVertexIndex)
{
    CVariable* pSelectedHandles = nullptr;
    if (pVertexIndex->IsImmediate())
    {
        unsigned int vertexIndex = int_cast<unsigned int>(pVertexIndex->GetImmediateValue());
        pSelectedHandles = GetNewVariable(numLanes(m_SIMDSize), ISA_TYPE_UD, EALIGN_GRF);

        if (m_properties.Input().HasInstancing())
        {
            encoder.SetSrcSubReg(0, vertexIndex);
        }
        else
        {
            encoder.SetSrcSubVar(0, vertexIndex);
        }
        
        encoder.Copy(pSelectedHandles, GetURBReadHandlesReg());
        encoder.Push();
    }
    else
    {
        CVariable* pOffset = GetNewVariable(numLanes(m_SIMDSize), ISA_TYPE_UW, EALIGN_GRF);
        CVariable* pVertexIndexWord = BitCast(pVertexIndex, ISA_TYPE_UW);
        if (!pVertexIndexWord->IsUniform())
        {
            encoder.SetSrcRegion(0, 16, 8, 2);
        }
        
        if(!m_properties.Input().HasInstancing())
        {
            // offset = vertexIndex * 32 since offset needs to be in bytes, not grf numbers
            CVariable* pTemp = GetNewVariable(pOffset);
            encoder.Shl(pTemp, pVertexIndexWord, ImmToVariable(5, ISA_TYPE_UW));
            encoder.Push();

            // offset = temp + perLaneOffsets
            // Offset is in 1 dword. So number of bytes is 4
            encoder.Add(pOffset, pTemp, GetPerLaneOffsetsReg(4));
            encoder.Push();
        }
        else
        {
            // When instancing is on each URB handle is 4 bytes, so we multiply by 4
            encoder.Shl(pOffset, pVertexIndexWord, ImmToVariable(2, ISA_TYPE_UW));
            encoder.Push();
        }

        // selectedHandles = addressof(urbhandles) + offsets2
        CVariable* URBHandles = GetURBReadHandlesReg();
        pSelectedHandles = GetNewAddressVariable(
            pOffset->IsUniform() ? 1 : numLanes(m_SIMDSize),
            ISA_TYPE_UD, 
            pOffset->IsUniform(), 
            URBHandles->IsUniform());
        encoder.AddrAdd(pSelectedHandles, URBHandles, pOffset);
        encoder.Push();
    }
    return pSelectedHandles;
}

QuadEltUnit CGeometryShader::GetFinalGlobalOffet(QuadEltUnit globalOffset)
{
    return globalOffset;
}

void CGeometryShader::AllocatePayload()
{
    uint offset = 0;

    // Allocate 8 DWORDS for the global URB Header which stores the cut bits.
    // The global header is 16 DWORDS which is a max of 512 bits.
    // So a GS can max output 1024 DWORDS/ 3 channels = 341 vertices 
    // (1024 max dwords so assuming no attributes).

    // R0 & R1 are always allocated.
    // R1 in our case is known as the URB Handle register to make it explicit
    // as to what it contains.
    //R0 is allocated as a predefined variable. Increase offset for R0
    assert(m_R0);
    offset += SIZE_GRF;

    // allocate input for URB return handles
    assert(m_pURBWriteHandleReg);
    AllocateInput(m_pURBWriteHandleReg, offset);
    offset += SIZE_GRF;

    // allocate input for primitiveID register if present
    if (m_pPrimitiveID != nullptr)
    {
        AllocateInput(m_pPrimitiveID, offset);
        offset += SIZE_GRF;
    }

    // allocate input for input vertex handles for pull model if required
    if (m_pURBReadHandlesReg != nullptr)
    {
        AllocateInput(m_pURBReadHandlesReg, offset);
        // the variable has the size equal to the number of vertices in the input primitive
        offset += m_pURBReadHandlesReg->GetSize();
        offset = iSTD::Align(offset, SIZE_GRF);
    }
    assert(offset % SIZE_GRF == 0);
    ProgramOutput()->m_startReg = offset / SIZE_GRF;

    // allocate space for NOS constants and pushed constants
    AllocateConstants3DShader(offset);;

    assert(offset % SIZE_GRF == 0);

    // when instancing mode is on, there is only one set of inputs and it's 
    // laid out like in constant buffers, i.e. one attribute takes four subregisters
    // of one GRF register.
    const uint varSize = m_properties.Input().HasInstancing() ? SIZE_DWORD : SIZE_GRF;
    for (uint i = 0; i < setup.size(); ++i)
    {
        if (setup[i])
        {
            AllocateInput(setup[i], offset);
        }
        offset += varSize;
    }
}

void CShaderProgram::FillProgram(SGeometryShaderKernelProgram* pKernelProgram)
{
    CGeometryShader* pShader = static_cast<CGeometryShader*>(GetShader(SIMDMode::SIMD8));
    pShader->FillProgram(pKernelProgram);
}

void CGeometryShader::FillProgram(SGeometryShaderKernelProgram* pKernelProgram)
{
    ProgramOutput()->m_scratchSpaceUsedByShader = m_ScratchSpaceSize;
    pKernelProgram->simd8 = *ProgramOutput();

    CreateGatherMap();
    CreateConstantBufferOutput(pKernelProgram);

    pKernelProgram->ConstantBufferLoaded = m_constantBufferLoaded;
    pKernelProgram->NOSBufferSize = m_NOSBufferSize/SIZE_GRF; // in 256 bits

    pKernelProgram->MaxNumberOfThreads = m_Platform->getMaxGeometryShaderThreads();
    pKernelProgram->hasControlFlow = m_numBlocks > 1 ? true : false;

    // Gen 7 specific Compiler Output
    pKernelProgram->OutputTopology = m_properties.Output().TopologyType();
    pKernelProgram->SamplerCount   = m_properties.SamplerCount();
    
    pKernelProgram->OutputVertexSize         = GetOutputVertexSize();
    pKernelProgram->VertexEntryReadLength    = GetVertexEntryReadLength();

    TODO("Fix compiler output structures for uninitialized fields");
    pKernelProgram->IncludeVertexHandles     = (m_pURBReadHandlesReg!=nullptr); // Used for PULL model. 
    pKernelProgram->VertexEntryReadOffset    = OctEltUnit(0);  // Include also vertex header, so start from the beginning.

    pKernelProgram->ControlDataHeaderFormat  = m_properties.Output().ControlDataFormat();
    pKernelProgram->GSEnable = true;

    // Default StreamID is also dependent on the GSEnable but since we set it to true here we are 
    // not considering it right now.
    auto defStreamID = m_properties.Output().DefaultStreamID();
    pKernelProgram->DefaultStreamID = (defStreamID != -1 ? defStreamID : 0);

    pKernelProgram->ControlDataHeaderSize = m_properties.Output().ControlDataHeaderSize();
    
    // Since we support only channel serial, the only mode for GS is SIMD8.
    pKernelProgram->DispatchMode = USC::GFX3DSTATE_GEOMETRY_SHADER_DISPATCH_MODE_SIMD8;
    
    pKernelProgram->IncludePrimitiveIDEnable    = (m_pPrimitiveID != nullptr);
    auto instanceCount = m_properties.Input().InstanceCount();
    pKernelProgram->InstanceCount               = (instanceCount == 0) ? 1 : instanceCount;
    pKernelProgram->ReorderEnable               = true;
    pKernelProgram->DiscardAdjacencyEnable      = CGeometryShader::DiscardAdjacency(m_properties.Input().InputPrimitiveType());
    pKernelProgram->SBEVertexURBEntryReadOffset = pKernelProgram->VertexEntryReadOffset;
 
    pKernelProgram->URBAllocationSize = GetURBAllocationSize();

    pKernelProgram->UserClipDistancesMask = m_properties.Output().PerVertex().ClipDistanceMask();
    pKernelProgram->UserCullDistancesMask = m_properties.Output().PerVertex().CullDistanceMask(); 

    pKernelProgram->MaxOutputVertexCount = m_properties.Output().MaxVertexCount();

    pKernelProgram->DeclaresVPAIndex = m_properties.Output().HasViewportArrayIndex();
    pKernelProgram->DeclaresRTAIndex = m_properties.Output().HasRenderTargetArrayIndex();

    pKernelProgram->SingleProgramFlow = USC::GFX3DSTATE_PROGRAM_FLOW_MULTIPLE;

    // Gen 8 specific Compiler Output
    TODO("Max threads should be calculated based on the registers spilled. -> This needs to change")
    pKernelProgram->ExpectedVertexCount   = m_properties.Input().VertexCount();
    pKernelProgram->StaticOutput          = !m_properties.Output().HasNonstaticVertexCount();
    
    pKernelProgram->StaticOutputVertexCount = 
        (m_properties.Output().HasNonstaticVertexCount()) ? 
            0 : m_properties.Output().ActualStaticVertexCount();

    pKernelProgram->GSVertexURBEntryOutputReadOffset = GetVertexURBEntryOutputReadOffset();
    pKernelProgram->GSVertexURBEntryOutputReadLength = GetVertexURBEntryOutputReadLength();

    pKernelProgram->bindingTableEntryCount  = this->GetMaxUsedBindingTableEntryCount();
    pKernelProgram->BindingTableEntryBitmap = this->GetBindingTableEntryBitmap();
}

void CGeometryShader::PreCompile()
{
    m_pURBWriteHandleReg = GetNewVariable(numLanes(m_SIMDSize), ISA_TYPE_UD, EALIGN_GRF);

    CreateImplicitArgs();
}

void CGeometryShader::AddPrologue()
{
    // add variable that represents instance ID
    if (m_properties.Input().HasInstanceID())
    {
        CEncoder& encoder = GetEncoder();
        m_pInstanceID = GetNewVariable(numLanes(m_SIMDSize), ISA_TYPE_UD, EALIGN_GRF);
        encoder.Shr(m_pInstanceID, m_pURBWriteHandleReg, ImmToVariable(27, ISA_TYPE_UD));
        encoder.Push();
    }
    // The 'include vertex handles' field must be set if the vertex URB entry read length is 0.
    if (m_properties.Input().PerVertex().Size().Count() == 0)
    {
        GetURBReadHandlesReg();
    }
}

void CGeometryShader::SetShaderSpecificHelper(EmitPass* emitPass)
{
    m_properties = emitPass->getAnalysisIfAvailable<CollectGeometryShaderProperties>()->GetProperties();
}

Unit<Element> CGeometryShader::GetLocalOffset(SGVUsage usage)
{
    switch(usage)
    {
    case POSITION_X:
        return Unit<Element>(0);
    case POSITION_Y:
        return Unit<Element>(1);
    case POSITION_Z:
        return Unit<Element>(2);
    case POSITION_W:
        return Unit<Element>(3);
    case POINT_WIDTH:
        return Unit<Element>(3);
    case CLIP_DISTANCE_X:
        return Unit<Element>(0);
    case CLIP_DISTANCE_Y:
        return Unit<Element>(1);
    case CLIP_DISTANCE_Z:
        return Unit<Element>(2);
    case CLIP_DISTANCE_W:
        return Unit<Element>(3);

    default:
            assert(0 && "Gs SGV Local offset not yet defined");
    }

    return Unit<Element>(0);
}

URBAllocationUnit CGeometryShader::GetURBAllocationSize() const
{
    // Calculate the size of all vertices to be emitted, rounded up to 32B.
    auto vertexCount = m_properties.Output().HasNonstaticVertexCount()? 
        m_properties.Output().MaxVertexCount() : m_properties.Output().ActualStaticVertexCount();

    const OctEltUnit vertexSpace = round_up<OctElement>(
        m_properties.Output().PerVertex().Size() * vertexCount );

    // Add the size of control data header and output vertex count structure.

    const OctEltUnit urbEntrySize =
        vertexSpace + m_properties.Output().GlobalHeaderSize();


    // URB allocation size is in units of 512 bits, so convert from 32B to 64B.
    return round_up<URBAllocation>(urbEntrySize);
}

/// Returns the size of the output vertex.
/// Unit: 16B = 4 DWORDs 
/// Note: Each output vertex must be 32B-aligned when rendering is enabled (Ref. GS URB Entry).
/// Therefore, the output vertex size is also rounded up to a multiple of 2.
QuadEltUnit CGeometryShader::GetOutputVertexSize() const
{
    QuadEltUnit vertexSize = m_properties.Output().PerVertex().Size();
    return vertexSize;
}

OctEltUnit CGeometryShader::GetInputVertexHeaderSize() const
{
    return m_properties.Input().PerVertex().HeaderSize();
}

OctEltUnit CGeometryShader::GetVertexEntryReadLength() const
{
    // if we use pull model, we don't use payload data and use URB read handles 
    // in that case Vertex Entry Read Length should be zero.
    // If we don't use URB read handles, we cannot have read length zero (even if we don't read
    // anything from inputs) because of hardware restriction.
    if (setup.size() == 0 && m_pURBReadHandlesReg != nullptr)
    {
        return OctEltUnit(0);
    }

    return round_up<OctElement>(m_properties.Input().PerVertex().Size());
}

OctEltUnit CGeometryShader::GetVertexURBEntryHeaderSize() const
{
    OctEltUnit headerSize = m_properties.Output().PerVertex().HeaderSize();
    return headerSize;
}

OctEltUnit  CGeometryShader::GetVertexURBEntryOutputReadLength() const
{
    // size that take all the output attributes
    const QuadEltUnit outAttribSpace(m_properties.Output().PerVertex().MaxAttributeCount());

    // OutputRead outputs attributes, possibly padded to be a multiple of 32B.
    return round_up<OctElement>(outAttribSpace);
}

OctEltUnit  CGeometryShader::GetVertexURBEntryOutputReadOffset() const
{
   // We tell SBE to skip the Vertex URB Entry header.
   return GetVertexURBEntryHeaderSize();
}

void CGeometryShader::AddEpilogue(llvm::ReturnInst *pRet)
{
    bool addDummyURB = true;
    if (pRet != &(*pRet->getParent()->begin()))
    {
        auto intinst = dyn_cast<GenIntrinsicInst>(pRet->getPrevNode());

        // if a URBWrite intrinsic is present no need to insert dummy urb write
        if (intinst && intinst->getIntrinsicID() == GenISAIntrinsic::GenISA_URBWrite)
        {
            addDummyURB = false;
        }
    }

    if (addDummyURB)
    {
        EmitEOTURBWrite();
    }

    CShader::AddEpilogue(pRet);
}

} // End of Namespace
