/*===================== begin_copyright_notice ==================================

Copyright (c) 2017 Intel Corporation

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


======================= end_copyright_notice ==================================*/
#include "CollectGeometryShaderProperties.hpp"

#include "Compiler/IGCPassSupport.h"
#include "common/LLVMWarningsPush.hpp"
#include <llvm/IR/Intrinsics.h>
#include <llvm/IR/Function.h>
#include <llvm/IR/InstVisitor.h>
#include "common/LLVMWarningsPop.hpp"
#include "GenISAIntrinsics/GenIntrinsics.h"
#include "Compiler/InitializePasses.h"

using namespace llvm;
using namespace IGC;


char CollectGeometryShaderProperties::ID = 0;
#define PASS_FLAG "collectgeometryshaderproperties"
#define PASS_DESCRIPTION "Collect GS Properties"
#define PASS_CFG_ONLY false
#define PASS_ANALYSIS false
IGC_INITIALIZE_PASS_BEGIN( CollectGeometryShaderProperties, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS )
IGC_INITIALIZE_PASS_END( CollectGeometryShaderProperties, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS )


CollectGeometryShaderProperties::CollectGeometryShaderProperties()
    : ImmutablePass(ID)
{
    initializeCollectGeometryShaderPropertiesPass( *PassRegistry::getPassRegistry() );
}


void CollectGeometryShaderProperties::gatherInformation(Function &F)
{
    ExtractGlobalVariables(F);
    CodeGenContext* ctx = getAnalysis<CodeGenContextWrapper>().getCodeGenContext();
    m_gsProps.Input().PerVertex().HasVertexHeader(ctx->getModuleMetaData()->URBInfo.hasVertexHeader);
    visit(F);
}

void CollectGeometryShaderProperties::visitCallInst(llvm::CallInst & I)
{
    if(GenIntrinsicInst *CI = dyn_cast<GenIntrinsicInst>(&I))
    {
        switch(CI->getIntrinsicID())
        {
        case llvm::GenISAIntrinsic::GenISA_GsCutControlHeader:
        case llvm::GenISAIntrinsic::GenISA_GsStreamHeader:
            {
                HandleCutOrStreamHeader(*CI);
                break;
            }

        case llvm::GenISAIntrinsic::GenISA_DCL_GSsystemValue:
        case llvm::GenISAIntrinsic::GenISA_DCL_SystemValue:
            {
                HandleSystemInput(*CI);
                break;
            }

        case llvm::GenISAIntrinsic::GenISA_OUTPUTGS:
            {
                HandleOutputWrite(*CI);
                break;
            }

        default:
            //nothing to do
            break;
        }
    }
}

void CollectGeometryShaderProperties::ExtractGlobalVariables( llvm::Function & F )
{
    llvm::Module *module = F.getParent();
    // GsMaxOutputVertices/GsOutputPrimitiveTopology are all global variables
    // set in the front-end with the same names. These have to be retrieved and typecast correctly.
    llvm::GlobalVariable* pGlobal = module->getGlobalVariable("GsMaxOutputVertices");
    unsigned int maxOutputVertices = int_cast<unsigned int>(llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue());
    m_gsProps.Output().MaxVertexCount(maxOutputVertices);

    pGlobal = module->getGlobalVariable("GsOutputPrimitiveTopology");
    auto outputTopologyType = static_cast<USC::GFX3DPRIMITIVE_TOPOLOGY_TYPE>
        (llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue());
    m_gsProps.Output().TopologyType(outputTopologyType);

    pGlobal = module->getGlobalVariable("SamplerCount");
    auto samplerCount = llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue();
    m_gsProps.SamplerCount(int_cast<unsigned int>(samplerCount));

    pGlobal = module->getGlobalVariable("GsInputPrimitiveType");
    auto inputPrimitiveType = static_cast<USC::GSHADER_INPUT_PRIMITIVE_TYPE>
        (llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue());
    m_gsProps.Input().InputPrimitiveType(inputPrimitiveType);

    pGlobal = module->getGlobalVariable("GsMaxInputAttributeCount");
    auto maxInputAttrCount = (llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue());
    m_gsProps.Input().PerVertex().MaxAttributeCount(int_cast<unsigned int>(maxInputAttrCount));

    pGlobal = module->getGlobalVariable("CutEncountered");
    auto cutEncountered = llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue() > 0 ? true : false;
    m_gsProps.Output().HasNontrivialCuts(cutEncountered);

    pGlobal = module->getGlobalVariable("DefaultStreamID");
    auto defaultStreamID = static_cast<int>(
        (llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue()));
    m_gsProps.Output().DefaultStreamID(defaultStreamID);

    pGlobal = module->getGlobalVariable("GsInstanceCount");
    auto instanceCount = (pGlobal == nullptr) ? 0 : 
        static_cast<unsigned int>(
        (llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue()));
    m_gsProps.Input().InstanceCount(instanceCount);

    // Frontend needs to provide information about which clip distances are in use by setting
    // bitmask value in the global variable GsOutputClipDistanceMask. Least significant bit
    // means clip plane #0 is used etc until bit 7 that corresponds to clip plane 7.
    pGlobal = module->getGlobalVariable("GsOutputClipDistanceMask");
    auto outputClipDistanceMask = 
        (pGlobal == nullptr) ? 0 : static_cast<unsigned int>(
            llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue());
    auto hasOutputClipDistances = outputClipDistanceMask != 0;
    m_gsProps.Output().PerVertex().HasClipDistances(hasOutputClipDistances);
    m_gsProps.Output().PerVertex().ClipDistanceMask(outputClipDistanceMask);

    // Deal with cull distances the same way as we do with clip distances.
    pGlobal = module->getGlobalVariable("GsOutputCullDistanceMask");
    auto outputCullDistanceMask = 
        (pGlobal == nullptr) ? 0 : static_cast<unsigned int>(
            llvm::cast<llvm::ConstantInt>(pGlobal->getInitializer())->getZExtValue());
    auto hasOutputCullDistances = outputCullDistanceMask != 0;
    m_gsProps.Output().PerVertex().HasCullDistances(hasOutputCullDistances);
    m_gsProps.Output().PerVertex().CullDistanceMask(outputCullDistanceMask);

    //see if clip and cull were sent as input
    pGlobal = module->getGlobalVariable("ShaderHasClipCullInput");
    auto clipCullAsInput = (pGlobal == nullptr) ? false : true;
    m_gsProps.Input().PerVertex().HasClipDistances(clipCullAsInput);
    CodeGenContext* context = getAnalysis<CodeGenContextWrapper>().getCodeGenContext();
    if (context->getModuleMetaData()->URBInfo.has64BVertexHeaderInput)
    {
        m_gsProps.Input().PerVertex().HasClipDistances(true);
        m_gsProps.Input().PerVertex().HasCullDistances(true);
    }
    if(context->getModuleMetaData()->URBInfo.has64BVertexHeaderOutput)
    {
        m_gsProps.Output().PerVertex().HasClipDistances(true);
        m_gsProps.Output().PerVertex().HasCullDistances(true);
    }

}

void CollectGeometryShaderProperties::HandleSystemInput(llvm::GenIntrinsicInst & I)
{
    unsigned int sgvIndex = I.getIntrinsicID() == llvm::GenISAIntrinsic::GenISA_DCL_GSsystemValue ? 1 : 0;
    SGVUsage usage = static_cast<SGVUsage>
        (llvm::cast<llvm::ConstantInt>(I.getOperand(sgvIndex))->getZExtValue());
    // If input usage contains clip distances, we need a bigger 
    // vertex header to accommodate for these values.
    switch (usage)
    {
    case CLIP_DISTANCE_X:
    case CLIP_DISTANCE_Y:
    case CLIP_DISTANCE_Z:
    case CLIP_DISTANCE_W:
        m_gsProps.Input().PerVertex().HasClipDistances(true);
        break;

    case GS_INSTANCEID:
        m_gsProps.Input().HasInstanceID(true);
        break;

    case PRIMITIVEID:
        m_gsProps.Input().HasPrimitiveID(true);
        break;
    default:
        break;
    }
}

void CollectGeometryShaderProperties::HandleOutputWrite(llvm::GenIntrinsicInst & I)
{
    const unsigned int shaderTypeArgIdx = 4;
    const unsigned int shaderAttrArgIdx = 5;
    ShaderOutputType outType =  static_cast<ShaderOutputType>(
        llvm::cast<llvm::ConstantInt>(I.getOperand(shaderTypeArgIdx))->getZExtValue());
    switch (outType)
    {
    case SHADER_OUTPUT_TYPE_CLIPDISTANCE_LO:
    case SHADER_OUTPUT_TYPE_CLIPDISTANCE_HI:
        // shader has output clip or cull distances
        // this should have been recognized already by global variable extraction 
        // that deals with clip or cull distance masks
        assert(m_gsProps.Output().PerVertex().HasClipDistances() ||
               m_gsProps.Output().PerVertex().HasCullDistances() );
        break;
    case SHADER_OUTPUT_TYPE_VIEWPORT_ARRAY_INDEX:
        m_gsProps.Output().HasViewportArrayIndex(true);
        break;
    case SHADER_OUTPUT_TYPE_RENDER_TARGET_ARRAY_INDEX:
        m_gsProps.Output().HasRenderTargetArrayIndex(true);
        break;
    case SHADER_OUTPUT_TYPE_DEFAULT:
        {
            unsigned int attribIdx = int_cast<unsigned int>(llvm::cast<llvm::ConstantInt>(
                I.getOperand(shaderAttrArgIdx))->getZExtValue());
            unsigned int maxattribcount = std::max(
                attribIdx+1, 
                m_gsProps.Output().PerVertex().MaxAttributeCount());
            m_gsProps.Output().PerVertex().MaxAttributeCount(maxattribcount);
            break;
        }
    default:
        // we don't need to do anything for them
        break;
    }
}

void CollectGeometryShaderProperties::HandleCutOrStreamHeader(llvm::GenIntrinsicInst & I)
{
    // set control data format based on the intrinsic type
    auto format = (I.getIntrinsicID() == llvm::GenISAIntrinsic::GenISA_GsCutControlHeader) ?
         USC::GFX3DSTATE_CONTROL_DATA_FORMAT_CUT : USC::GFX3DSTATE_CONTROL_DATA_FORMAT_SID;
    m_gsProps.Output().ControlDataFormat(format);

    auto pVertexCount = llvm::dyn_cast<llvm::ConstantInt>(I.getOperand(I.getNumOperands()-2));
    // if the emitCount is not a constant int, we have runtime value of vertex count
    m_gsProps.Output().HasNonstaticVertexCount(pVertexCount == nullptr);

    // for static number of vertices, we get the actual value, 
    // for dynamic, declaration-derived upper bound (for safety)
    const unsigned int numVertices = (pVertexCount != nullptr) ?
        int_cast<unsigned int>(pVertexCount->getZExtValue()) : m_gsProps.Output().MaxVertexCount();

    m_gsProps.Output().ActualStaticVertexCount(numVertices);

    if (IGC_IS_FLAG_ENABLED(EnableGSURBEntryPadding))
    {
        if (!m_gsProps.Output().ControlDataHeaderRequired() &&
            m_gsProps.Output().HasNonstaticVertexCount())
        {
            m_gsProps.Output().SetControlDataHeaderPaddingRequired(true);
            m_gsProps.Output().ControlDataFormat(USC::GFX3DSTATE_CONTROL_DATA_FORMAT_CUT);
        }
    }
    if (IGC_IS_FLAG_ENABLED(EnableGSVtxCountMsgHalfCLSize))
    {
        if (m_gsProps.Output().HasNonstaticVertexCount())
        {
            m_gsProps.Output().HasVtxCountMsgHalfCLSize(true);
        }
    }
}

