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kc3-lang/angle/src/compiler/translator/StructureHLSL.cpp

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  • Author : Xinghua Cao
    Date : 2021-03-29 17:18:52
    Hash : 80305ca4
    Message : D3D: fix uniform block alignment error If the uniform block will be translated to HLSL StructuredBuffer, in order to follow the std140 rules, we should add padding between the members if necessary. Bug: chromium:1193170 Change-Id: I75bc3538a66fc0c2a9c9ebf15fddeaab94d7a949 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2790518 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jiajia Qin <jiajia.qin@intel.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Xinghua Cao <xinghua.cao@intel.com>

  • src/compiler/translator/StructureHLSL.cpp 
  • //
// Copyright 2014 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// StructureHLSL.cpp:
//   HLSL translation of GLSL constructors and structures.
//

#include "compiler/translator/StructureHLSL.h"
#include "common/utilities.h"
#include "compiler/translator/OutputHLSL.h"
#include "compiler/translator/Types.h"
#include "compiler/translator/UtilsHLSL.h"
#include "compiler/translator/util.h"

namespace sh
{

namespace
{

TString Define(const TStructure &structure,
               bool useHLSLRowMajorPacking,
               bool useStd140Packing,
               bool forcePadding,
               Std140PaddingHelper *padHelper)
{
    const TFieldList &fields    = structure.fields();
    const bool isNameless       = (structure.symbolType() == SymbolType::Empty);
    const TString &structName   = QualifiedStructNameString(structure, useHLSLRowMajorPacking,
                                                          useStd140Packing, forcePadding);
    const TString declareString = (isNameless ? "struct" : "struct " + structName);

    TString string;
    string += declareString +
              "\n"
              "{\n";

    size_t memberSize = fields.size();
    for (const TField *field : fields)
    {
        memberSize--;
        const TType &fieldType = *field->type();
        if (!IsSampler(fieldType.getBasicType()))
        {
            const TStructure *fieldStruct = fieldType.getStruct();
            const TString &fieldTypeString =
                fieldStruct ? QualifiedStructNameString(*fieldStruct, useHLSLRowMajorPacking,
                                                        useStd140Packing, false)
                            : TypeString(fieldType);

            if (padHelper)
            {
                string += padHelper->prePaddingString(
                    fieldType, (memberSize != fields.size() - 1) && forcePadding);
            }

            string += "    " + fieldTypeString + " " + DecorateField(field->name(), structure) +
                      ArrayString(fieldType).data() + ";\n";

            if (padHelper)
            {
                string += padHelper->postPaddingString(fieldType, useHLSLRowMajorPacking,
                                                       memberSize == 0, forcePadding);
            }
        }
    }

    // Nameless structs do not finish with a semicolon and newline, to leave room for an instance
    // variable
    string += (isNameless ? "} " : "};\n");

    return string;
}

TString WriteParameterList(const std::vector<TType> &parameters)
{
    TString parameterList;
    for (size_t parameter = 0u; parameter < parameters.size(); parameter++)
    {
        const TType &paramType = parameters[parameter];

        parameterList +=
            TypeString(paramType) + " x" + str(parameter) + ArrayString(paramType).data();

        if (parameter < parameters.size() - 1u)
        {
            parameterList += ", ";
        }
    }
    return parameterList;
}

int GetElementPadding(int elementIndex, int alignment)
{
    const int paddingOffset = elementIndex % alignment;
    return paddingOffset != 0 ? (alignment - paddingOffset) : 0;
}

}  // anonymous namespace

Std140PaddingHelper::Std140PaddingHelper(const std::map<TString, int> &structElementIndexes,
                                         unsigned *uniqueCounter)
    : mPaddingCounter(uniqueCounter), mElementIndex(0), mStructElementIndexes(&structElementIndexes)
{}

Std140PaddingHelper::Std140PaddingHelper(const Std140PaddingHelper &other)
    : mPaddingCounter(other.mPaddingCounter),
      mElementIndex(other.mElementIndex),
      mStructElementIndexes(other.mStructElementIndexes)
{}

Std140PaddingHelper &Std140PaddingHelper::operator=(const Std140PaddingHelper &other)
{
    mPaddingCounter       = other.mPaddingCounter;
    mElementIndex         = other.mElementIndex;
    mStructElementIndexes = other.mStructElementIndexes;
    return *this;
}

TString Std140PaddingHelper::next()
{
    unsigned value = (*mPaddingCounter)++;
    return str(value);
}

int Std140PaddingHelper::prePadding(const TType &type, bool forcePadding)
{
    if (type.getBasicType() == EbtStruct || type.isMatrix() || type.isArray())
    {
        if (forcePadding)
        {
            // Add padding between the structure's members to follow the std140 rules manually.
            const int forcePaddingCount = GetElementPadding(mElementIndex, 4);
            mElementIndex               = 0;
            return forcePaddingCount;
        }
        else
        {
            // no padding needed, HLSL will align the field to a new register
            mElementIndex = 0;
            return 0;
        }
    }

    const GLenum glType     = GLVariableType(type);
    const int numComponents = gl::VariableComponentCount(glType);

    if (numComponents >= 4)
    {
        if (forcePadding)
        {
            // Add padding between the structure's members to follow the std140 rules manually.
            const int forcePaddingCount = GetElementPadding(mElementIndex, 4);
            mElementIndex               = numComponents % 4;
            return forcePaddingCount;
        }
        else
        {
            // no padding needed, HLSL will align the field to a new register
            mElementIndex = 0;
            return 0;
        }
    }

    if (mElementIndex + numComponents > 4)
    {
        if (forcePadding)
        {
            // Add padding between the structure's members to follow the std140 rules manually.
            const int forcePaddingCount = GetElementPadding(mElementIndex, 4);
            mElementIndex               = numComponents;
            return forcePaddingCount;
        }
        else
        {
            // no padding needed, HLSL will align the field to a new register
            mElementIndex = numComponents;
            return 0;
        }
    }

    const int alignment    = numComponents == 3 ? 4 : numComponents;
    const int paddingCount = GetElementPadding(mElementIndex, alignment);

    mElementIndex += paddingCount;
    mElementIndex += numComponents;
    mElementIndex %= 4;

    return paddingCount;
}

TString Std140PaddingHelper::prePaddingString(const TType &type, bool forcePadding)
{
    int paddingCount = prePadding(type, forcePadding);

    TString padding;

    for (int paddingIndex = 0; paddingIndex < paddingCount; paddingIndex++)
    {
        padding += "    float pad_" + next() + ";\n";
    }

    return padding;
}

TString Std140PaddingHelper::postPaddingString(const TType &type,
                                               bool useHLSLRowMajorPacking,
                                               bool isLastElement,
                                               bool forcePadding)
{
    if (!type.isMatrix() && !type.isArray() && type.getBasicType() != EbtStruct)
    {
        if (forcePadding)
        {
            const GLenum glType     = GLVariableType(type);
            const int numComponents = gl::VariableComponentCount(glType);
            if (isLastElement || (numComponents >= 4))
            {
                // If this structure will be used as HLSL StructuredBuffer member's type, in
                // order to follow the std140 rules, add padding at the end of the structure
                // if necessary. Or if the current element straddles a vec4 boundary, add
                // padding to round up the base offset of the next element to the base
                // alignment of a vec4.
                TString forcePaddingStr;
                const int paddingCount = GetElementPadding(mElementIndex, 4);
                for (int paddingIndex = 0; paddingIndex < paddingCount; paddingIndex++)
                {
                    forcePaddingStr += "    float pad_" + next() + ";\n";
                }
                mElementIndex = 0;
                return forcePaddingStr;
            }
        }

        return "";
    }

    int numComponents           = 0;
    const TStructure *structure = type.getStruct();

    if (type.isMatrix())
    {
        // This method can also be called from structureString, which does not use layout
        // qualifiers.
        // Thus, use the method parameter for determining the matrix packing.
        //
        // Note HLSL row major packing corresponds to GL API column-major, and vice-versa, since we
        // wish to always transpose GL matrices to play well with HLSL's matrix array indexing.
        //
        const bool isRowMajorMatrix = !useHLSLRowMajorPacking;
        const GLenum glType         = GLVariableType(type);
        numComponents               = gl::MatrixComponentCount(glType, isRowMajorMatrix);
    }
    else if (structure)
    {
        const TString &structName =
            QualifiedStructNameString(*structure, useHLSLRowMajorPacking, true, false);
        numComponents = mStructElementIndexes->find(structName)->second;

        if (numComponents == 0)
        {
            return "";
        }
    }
    else
    {
        const GLenum glType = GLVariableType(type);
        numComponents       = gl::VariableComponentCount(glType);
    }

    TString padding;
    for (int paddingOffset = numComponents; paddingOffset < 4; paddingOffset++)
    {
        padding += "    float pad_" + next() + ";\n";
    }
    return padding;
}

StructureHLSL::StructureHLSL() : mUniquePaddingCounter(0) {}

Std140PaddingHelper StructureHLSL::getPaddingHelper()
{
    return Std140PaddingHelper(mStd140StructElementIndexes, &mUniquePaddingCounter);
}

TString StructureHLSL::defineQualified(const TStructure &structure,
                                       bool useHLSLRowMajorPacking,
                                       bool useStd140Packing,
                                       bool forcePadding)
{
    if (useStd140Packing)
    {
        Std140PaddingHelper padHelper = getPaddingHelper();
        return Define(structure, useHLSLRowMajorPacking, useStd140Packing, forcePadding,
                      &padHelper);
    }
    else
    {
        return Define(structure, useHLSLRowMajorPacking, useStd140Packing, false, nullptr);
    }
}

TString StructureHLSL::defineNameless(const TStructure &structure)
{
    return Define(structure, false, false, false, nullptr);
}

StructureHLSL::DefinedStructs::iterator StructureHLSL::defineVariants(const TStructure &structure,
                                                                      const TString &name)
{
    ASSERT(mDefinedStructs.find(name) == mDefinedStructs.end());

    for (const TField *field : structure.fields())
    {
        const TType *fieldType = field->type();
        if (fieldType->getBasicType() == EbtStruct)
        {
            ensureStructDefined(*fieldType->getStruct());
        }
    }

    DefinedStructs::iterator addedStruct =
        mDefinedStructs.insert(std::make_pair(name, new TStructProperties())).first;
    // Add element index
    storeStd140ElementIndex(structure, false);
    storeStd140ElementIndex(structure, true);

    const TString &structString = defineQualified(structure, false, false, false);

    ASSERT(std::find(mStructDeclarations.begin(), mStructDeclarations.end(), structString) ==
           mStructDeclarations.end());
    // Add row-major packed struct for interface blocks
    TString rowMajorString = "#pragma pack_matrix(row_major)\n" +
                             defineQualified(structure, true, false, false) +
                             "#pragma pack_matrix(column_major)\n";

    TString std140String         = defineQualified(structure, false, true, false);
    TString std140RowMajorString = "#pragma pack_matrix(row_major)\n" +
                                   defineQualified(structure, true, true, false) +
                                   "#pragma pack_matrix(column_major)\n";

    // Must force to pad the structure's elements for StructuredBuffer's element type, if qualifier
    // of structure is std140.
    TString std140ForcePaddingString         = defineQualified(structure, false, true, true);
    TString std140RowMajorForcePaddingString = "#pragma pack_matrix(row_major)\n" +
                                               defineQualified(structure, true, true, true) +
                                               "#pragma pack_matrix(column_major)\n";

    mStructDeclarations.push_back(structString);
    mStructDeclarations.push_back(rowMajorString);
    mStructDeclarations.push_back(std140String);
    mStructDeclarations.push_back(std140RowMajorString);
    mStructDeclarations.push_back(std140ForcePaddingString);
    mStructDeclarations.push_back(std140RowMajorForcePaddingString);
    return addedStruct;
}

void StructureHLSL::ensureStructDefined(const TStructure &structure)
{
    const TString name = StructNameString(structure);
    if (name == "")
    {
        return;  // Nameless structures are not defined
    }
    if (mDefinedStructs.find(name) == mDefinedStructs.end())
    {
        defineVariants(structure, name);
    }
}

TString StructureHLSL::addStructConstructor(const TStructure &structure)
{
    const TString name = StructNameString(structure);

    if (name == "")
    {
        return TString();  // Nameless structures don't have constructors
    }

    auto definedStruct = mDefinedStructs.find(name);
    if (definedStruct == mDefinedStructs.end())
    {
        definedStruct = defineVariants(structure, name);
    }
    const TString constructorFunctionName = TString(name) + "_ctor";
    TString *constructor                  = &definedStruct->second->constructor;
    if (!constructor->empty())
    {
        return constructorFunctionName;  // Already added
    }
    *constructor += name + " " + constructorFunctionName + "(";

    std::vector<TType> ctorParameters;
    const TFieldList &fields = structure.fields();
    for (const TField *field : fields)
    {
        const TType *fieldType = field->type();
        if (!IsSampler(fieldType->getBasicType()))
        {
            ctorParameters.push_back(*fieldType);
        }
    }
    // Structs that have sampler members should not have constructor calls, and otherwise structs
    // are guaranteed to be non-empty by the grammar. Structs can't contain empty declarations
    // either.
    ASSERT(!ctorParameters.empty());

    *constructor += WriteParameterList(ctorParameters);

    *constructor +=
        ")\n"
        "{\n"
        "    " +
        name + " structure = { ";

    for (size_t parameterIndex = 0u; parameterIndex < ctorParameters.size(); ++parameterIndex)
    {
        *constructor += "x" + str(parameterIndex);
        if (parameterIndex < ctorParameters.size() - 1u)
        {
            *constructor += ", ";
        }
    }
    *constructor +=
        "};\n"
        "    return structure;\n"
        "}\n";

    return constructorFunctionName;
}

TString StructureHLSL::addBuiltInConstructor(const TType &type, const TIntermSequence *parameters)
{
    ASSERT(!type.isArray());
    ASSERT(type.getStruct() == nullptr);
    ASSERT(parameters);

    TType ctorType = type;
    ctorType.setPrecision(EbpHigh);
    ctorType.setQualifier(EvqTemporary);

    const TString constructorFunctionName =
        TString(type.getBuiltInTypeNameString()) + "_ctor" + DisambiguateFunctionName(parameters);
    TString constructor = TypeString(ctorType) + " " + constructorFunctionName + "(";

    std::vector<TType> ctorParameters;
    for (auto parameter : *parameters)
    {
        const TType &paramType = parameter->getAsTyped()->getType();
        ASSERT(!paramType.isArray());
        ctorParameters.push_back(paramType);
    }
    constructor += WriteParameterList(ctorParameters);

    constructor +=
        ")\n"
        "{\n"
        "    return " +
        TypeString(ctorType) + "(";

    if (ctorType.isMatrix() && ctorParameters.size() == 1)
    {
        int rows               = ctorType.getRows();
        int cols               = ctorType.getCols();
        const TType &parameter = ctorParameters[0];

        if (parameter.isScalar())
        {
            for (int col = 0; col < cols; col++)
            {
                for (int row = 0; row < rows; row++)
                {
                    constructor += TString((row == col) ? "x0" : "0.0");

                    if (row < rows - 1 || col < cols - 1)
                    {
                        constructor += ", ";
                    }
                }
            }
        }
        else if (parameter.isMatrix())
        {
            for (int col = 0; col < cols; col++)
            {
                for (int row = 0; row < rows; row++)
                {
                    if (row < parameter.getRows() && col < parameter.getCols())
                    {
                        constructor += TString("x0") + "[" + str(col) + "][" + str(row) + "]";
                    }
                    else
                    {
                        constructor += TString((row == col) ? "1.0" : "0.0");
                    }

                    if (row < rows - 1 || col < cols - 1)
                    {
                        constructor += ", ";
                    }
                }
            }
        }
        else
        {
            ASSERT(rows == 2 && cols == 2 && parameter.isVector() &&
                   parameter.getNominalSize() == 4);

            constructor += "x0";
        }
    }
    else
    {
        size_t remainingComponents = ctorType.getObjectSize();
        size_t parameterIndex      = 0;

        while (remainingComponents > 0)
        {
            const TType &parameter     = ctorParameters[parameterIndex];
            const size_t parameterSize = parameter.getObjectSize();
            bool moreParameters        = parameterIndex + 1 < ctorParameters.size();

            constructor += "x" + str(parameterIndex);

            if (parameter.isScalar())
            {
                remainingComponents -= parameter.getObjectSize();
            }
            else if (parameter.isVector())
            {
                if (remainingComponents == parameterSize || moreParameters)
                {
                    ASSERT(parameterSize <= remainingComponents);
                    remainingComponents -= parameterSize;
                }
                else if (remainingComponents < static_cast<size_t>(parameter.getNominalSize()))
                {
                    switch (remainingComponents)
                    {
                        case 1:
                            constructor += ".x";
                            break;
                        case 2:
                            constructor += ".xy";
                            break;
                        case 3:
                            constructor += ".xyz";
                            break;
                        case 4:
                            constructor += ".xyzw";
                            break;
                        default:
                            UNREACHABLE();
                    }

                    remainingComponents = 0;
                }
                else
                    UNREACHABLE();
            }
            else if (parameter.isMatrix())
            {
                int column = 0;
                while (remainingComponents > 0 && column < parameter.getCols())
                {
                    constructor += "[" + str(column) + "]";

                    if (remainingComponents < static_cast<size_t>(parameter.getRows()))
                    {
                        switch (remainingComponents)
                        {
                            case 1:
                                constructor += ".x";
                                break;
                            case 2:
                                constructor += ".xy";
                                break;
                            case 3:
                                constructor += ".xyz";
                                break;
                            default:
                                UNREACHABLE();
                        }

                        remainingComponents = 0;
                    }
                    else
                    {
                        remainingComponents -= parameter.getRows();

                        if (remainingComponents > 0)
                        {
                            constructor += ", x" + str(parameterIndex);
                        }
                    }

                    column++;
                }
            }
            else
            {
                UNREACHABLE();
            }

            if (moreParameters)
            {
                parameterIndex++;
            }

            if (remainingComponents)
            {
                constructor += ", ";
            }
        }
    }

    constructor +=
        ");\n"
        "}\n";

    mBuiltInConstructors.insert(constructor);

    return constructorFunctionName;
}

std::string StructureHLSL::structsHeader() const
{
    TInfoSinkBase out;

    for (auto &declaration : mStructDeclarations)
    {
        out << declaration;
    }

    for (auto &structure : mDefinedStructs)
    {
        out << structure.second->constructor;
    }

    for (auto &constructor : mBuiltInConstructors)
    {
        out << constructor;
    }

    return out.str();
}

void StructureHLSL::storeStd140ElementIndex(const TStructure &structure,
                                            bool useHLSLRowMajorPacking)
{
    Std140PaddingHelper padHelper = getPaddingHelper();
    const TFieldList &fields      = structure.fields();

    for (const TField *field : fields)
    {
        padHelper.prePadding(*field->type(), false);
    }

    // Add remaining element index to the global map, for use with nested structs in standard
    // layouts
    const TString &structName =
        QualifiedStructNameString(structure, useHLSLRowMajorPacking, true, false);
    mStd140StructElementIndexes[structName] = padHelper.elementIndex();
}

}  // namespace sh