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

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  • Author : Charlie Lao
    Date : 2020-11-18 20:33:33
    Hash : 995493cc
    Message : Revert "Vulkan: Remove rotation related data from driver uniform" This reverts commit fd97c3343e9ff23677124b7528ec945bca65796a. Reason for revert: The specialization constant for rotation causes performance regression with older qualcomm driver. We need to keep the driver uniform code path for the older driver. Original change's description: > Vulkan: Remove rotation related data from driver uniform > > Rotation is now handled in the shader compiler with specialization > constant, it should be removed from driver uniforms. Since Metal is > using the flipXY, flipXY/negFlipXY are still kept in the shader side > implementation, but have moved to TranslatorMetal in this CL. > > Bug: b/171750979 > Change-Id: Ie8d15ef227cb52a6e19e4319ecc9f09bda42e667 > Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2519863 > Reviewed-by: Ian Elliott <ianelliott@google.com> > Reviewed-by: Tim Van Patten <timvp@google.com> > Reviewed-by: Jamie Madill <jmadill@chromium.org> > Commit-Queue: Charlie Lao <cclao@google.com> TBR=ianelliott@google.com,timvp@google.com,jmadill@chromium.org,cclao@google.com Bug: b/171750979 Change-Id: Iff9cffb28851ade1d9c5cd23fde73910a19867ce Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2547808 Reviewed-by: Ian Elliott <ianelliott@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: Charlie Lao <cclao@google.com>

  • src/compiler/translator/TranslatorMetal.cpp
  • //
    // Copyright (c) 2019 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.
    //
    // TranslatorMetal:
    //   A GLSL-based translator that outputs shaders that fit GL_KHR_vulkan_glsl.
    //   It takes into account some considerations for Metal backend also.
    //   The shaders are then fed into glslang to spit out SPIR-V (libANGLE-side).
    //   See: https://www.khronos.org/registry/vulkan/specs/misc/GL_KHR_vulkan_glsl.txt
    //
    //   The SPIR-V will then be translated to Metal Shading Language later in Metal backend.
    //
    
    #include "compiler/translator/TranslatorMetal.h"
    
    #include "angle_gl.h"
    #include "common/utilities.h"
    #include "compiler/translator/OutputVulkanGLSLForMetal.h"
    #include "compiler/translator/StaticType.h"
    #include "compiler/translator/tree_ops/InitializeVariables.h"
    #include "compiler/translator/tree_util/BuiltIn.h"
    #include "compiler/translator/tree_util/DriverUniform.h"
    #include "compiler/translator/tree_util/FindMain.h"
    #include "compiler/translator/tree_util/FindSymbolNode.h"
    #include "compiler/translator/tree_util/IntermNode_util.h"
    #include "compiler/translator/tree_util/ReplaceArrayOfMatrixVarying.h"
    #include "compiler/translator/tree_util/ReplaceVariable.h"
    #include "compiler/translator/tree_util/RunAtTheEndOfShader.h"
    #include "compiler/translator/util.h"
    
    namespace sh
    {
    
    namespace mtl
    {
    /** extern */
    const char kCoverageMaskEnabledConstName[]      = "ANGLECoverageMaskEnabled";
    const char kRasterizerDiscardEnabledConstName[] = "ANGLERasterizerDisabled";
    }  // namespace mtl
    
    namespace
    {
    // Metal specific driver uniforms
    constexpr const char kCoverageMask[] = "coverageMask";
    
    constexpr ImmutableString kSampleMaskWriteFuncName = ImmutableString("ANGLEWriteSampleMask");
    
    // Unlike Vulkan having auto viewport flipping extension, in Metal we have to flip gl_Position.y
    // manually.
    // This operation performs flipping the gl_Position.y using this expression:
    // gl_Position.y = gl_Position.y * negViewportScaleY
    ANGLE_NO_DISCARD bool AppendVertexShaderPositionYCorrectionToMain(TCompiler *compiler,
                                                                      TIntermBlock *root,
                                                                      TSymbolTable *symbolTable,
                                                                      TIntermTyped *negFlipY)
    {
        // Create a symbol reference to "gl_Position"
        const TVariable *position  = BuiltInVariable::gl_Position();
        TIntermSymbol *positionRef = new TIntermSymbol(position);
    
        // Create a swizzle to "gl_Position.y"
        TVector<int> swizzleOffsetY;
        swizzleOffsetY.push_back(1);
        TIntermSwizzle *positionY = new TIntermSwizzle(positionRef, swizzleOffsetY);
    
        // Create the expression "gl_Position.y * negFlipY"
        TIntermBinary *inverseY = new TIntermBinary(EOpMul, positionY->deepCopy(), negFlipY);
    
        // Create the assignment "gl_Position.y = gl_Position.y * negViewportScaleY
        TIntermTyped *positionYLHS = positionY->deepCopy();
        TIntermBinary *assignment  = new TIntermBinary(TOperator::EOpAssign, positionYLHS, inverseY);
    
        // Append the assignment as a statement at the end of the shader.
        return RunAtTheEndOfShader(compiler, root, assignment, symbolTable);
    }
    
    // Initialize unused varying outputs.
    ANGLE_NO_DISCARD bool InitializeUnusedOutputs(TIntermBlock *root,
                                                  TSymbolTable *symbolTable,
                                                  const InitVariableList &unusedVars)
    {
        if (unusedVars.empty())
        {
            return true;
        }
    
        TIntermSequence *insertSequence = new TIntermSequence;
    
        for (const sh::ShaderVariable &var : unusedVars)
        {
            ASSERT(!var.active);
            const TIntermSymbol *symbol = FindSymbolNode(root, var.name);
            ASSERT(symbol);
    
            TIntermSequence *initCode = CreateInitCode(symbol, false, false, symbolTable);
    
            insertSequence->insert(insertSequence->end(), initCode->begin(), initCode->end());
        }
    
        if (insertSequence)
        {
            TIntermFunctionDefinition *main = FindMain(root);
            TIntermSequence *mainSequence   = main->getBody()->getSequence();
    
            // Insert init code at the start of main()
            mainSequence->insert(mainSequence->begin(), insertSequence->begin(), insertSequence->end());
        }
    
        return true;
    }
    }  // anonymous namespace
    
    TFieldList *DriverUniformMetal::createUniformFields(TSymbolTable *symbolTable) const
    {
        TFieldList *driverFieldList = DriverUniform::createUniformFields(symbolTable);
    
        // Add coverage mask to driver uniform. Metal doesn't have built-in GL_SAMPLE_COVERAGE_VALUE
        // equivalent functionality, needs to emulate it using fragment shader's [[sample_mask]] output
        // value.
        TField *coverageMaskField = new TField(new TType(EbtUInt), ImmutableString(kCoverageMask),
                                               TSourceLoc(), SymbolType::AngleInternal);
        driverFieldList->push_back(coverageMaskField);
    
        return driverFieldList;
    }
    
    TIntermBinary *DriverUniformMetal::getCoverageMaskFieldRef() const
    {
        return createDriverUniformRef(kCoverageMask);
    }
    
    TranslatorMetal::TranslatorMetal(sh::GLenum type, ShShaderSpec spec) : TranslatorVulkan(type, spec)
    {}
    
    bool TranslatorMetal::translate(TIntermBlock *root,
                                    ShCompileOptions compileOptions,
                                    PerformanceDiagnostics *perfDiagnostics)
    {
        TInfoSinkBase &sink = getInfoSink().obj;
    
        TOutputVulkanGLSL outputGLSL(sink, getArrayIndexClampingStrategy(), getHashFunction(),
                                     getNameMap(), &getSymbolTable(), getShaderType(),
                                     getShaderVersion(), getOutputType(), false, true, compileOptions);
    
        DriverUniformMetal driverUniforms;
        if (!TranslatorVulkan::translateImpl(root, compileOptions, perfDiagnostics, &driverUniforms,
                                             &outputGLSL))
        {
            return false;
        }
    
        // Replace array of matrix varyings
        if (!ReplaceArrayOfMatrixVaryings(this, root, &getSymbolTable()))
        {
            return false;
        }
    
        if (getShaderType() == GL_VERTEX_SHADER)
        {
            TIntermTyped *negFlipY = driverUniforms.getNegFlipYRef();
    
            // Append gl_Position.y correction to main
            if (!AppendVertexShaderPositionYCorrectionToMain(this, root, &getSymbolTable(), negFlipY))
            {
                return false;
            }
    
            // Insert rasterizer discard logic
            if (!insertRasterizerDiscardLogic(root))
            {
                return false;
            }
        }
        else if (getShaderType() == GL_FRAGMENT_SHADER)
        {
            if (!insertSampleMaskWritingLogic(root, &driverUniforms))
            {
                return false;
            }
        }
    
        // Initialize unused varying outputs to avoid spirv-cross dead-code removing them in later
        // stage. Only do this if SH_INIT_OUTPUT_VARIABLES is not specified.
        if ((getShaderType() == GL_VERTEX_SHADER || getShaderType() == GL_GEOMETRY_SHADER_EXT) &&
            !(compileOptions & SH_INIT_OUTPUT_VARIABLES))
        {
            InitVariableList list;
            for (const sh::ShaderVariable &var : mOutputVaryings)
            {
                if (!var.active)
                {
                    list.push_back(var);
                }
            }
    
            if (!InitializeUnusedOutputs(root, &getSymbolTable(), list))
            {
                return false;
            }
        }
    
        // Write translated shader.
        root->traverse(&outputGLSL);
    
        return true;
    }
    
    // Metal needs to inverse the depth if depthRange is is reverse order, i.e. depth near > depth far
    // This is achieved by multiply the depth value with scale value stored in
    // driver uniform's depthRange.reserved
    bool TranslatorMetal::transformDepthBeforeCorrection(TIntermBlock *root,
                                                         const DriverUniform *driverUniforms)
    {
        // Create a symbol reference to "gl_Position"
        const TVariable *position  = BuiltInVariable::gl_Position();
        TIntermSymbol *positionRef = new TIntermSymbol(position);
    
        // Create a swizzle to "gl_Position.z"
        TVector<int> swizzleOffsetZ = {2};
        TIntermSwizzle *positionZ   = new TIntermSwizzle(positionRef, swizzleOffsetZ);
    
        // Create a ref to "depthRange.reserved"
        TIntermBinary *viewportZScale = driverUniforms->getDepthRangeReservedFieldRef();
    
        // Create the expression "gl_Position.z * depthRange.reserved".
        TIntermBinary *zScale = new TIntermBinary(EOpMul, positionZ->deepCopy(), viewportZScale);
    
        // Create the assignment "gl_Position.z = gl_Position.z * depthRange.reserved"
        TIntermTyped *positionZLHS = positionZ->deepCopy();
        TIntermBinary *assignment  = new TIntermBinary(TOperator::EOpAssign, positionZLHS, zScale);
    
        // Append the assignment as a statement at the end of the shader.
        return RunAtTheEndOfShader(this, root, assignment, &getSymbolTable());
    }
    
    // Add sample_mask writing to main, guarded by the specialization constant
    // kCoverageMaskEnabledConstName
    ANGLE_NO_DISCARD bool TranslatorMetal::insertSampleMaskWritingLogic(
        TIntermBlock *root,
        const DriverUniformMetal *driverUniforms)
    {
        TInfoSinkBase &sink       = getInfoSink().obj;
        TSymbolTable *symbolTable = &getSymbolTable();
    
        // Insert coverageMaskEnabled specialization constant and sample_mask writing function.
        sink << "layout (constant_id=0) const bool " << mtl::kCoverageMaskEnabledConstName;
        sink << " = false;\n";
        sink << "void " << kSampleMaskWriteFuncName << "(uint mask)\n";
        sink << "{\n";
        sink << "   if (" << mtl::kCoverageMaskEnabledConstName << ")\n";
        sink << "   {\n";
        sink << "       gl_SampleMask[0] = int(mask);\n";
        sink << "   }\n";
        sink << "}\n";
    
        // Create kCoverageMaskEnabledConstName and kSampleMaskWriteFuncName variable references.
        TType *boolType = new TType(EbtBool);
        boolType->setQualifier(EvqConst);
        TVariable *coverageMaskEnabledVar =
            new TVariable(symbolTable, ImmutableString(mtl::kCoverageMaskEnabledConstName), boolType,
                          SymbolType::AngleInternal);
    
        TFunction *sampleMaskWriteFunc =
            new TFunction(symbolTable, kSampleMaskWriteFuncName, SymbolType::AngleInternal,
                          StaticType::GetBasic<EbtVoid>(), false);
    
        TType *uintType = new TType(EbtUInt);
        TVariable *maskArg =
            new TVariable(symbolTable, ImmutableString("mask"), uintType, SymbolType::AngleInternal);
        sampleMaskWriteFunc->addParameter(maskArg);
    
        // coverageMask
        TIntermBinary *coverageMask = driverUniforms->getCoverageMaskFieldRef();
    
        // Insert this code to the end of main()
        // if (ANGLECoverageMaskEnabled)
        // {
        //      ANGLEWriteSampleMask(ANGLEUniforms.coverageMask);
        // }
        TIntermSequence *args = new TIntermSequence;
        args->push_back(coverageMask);
        TIntermAggregate *callSampleMaskWriteFunc =
            TIntermAggregate::CreateFunctionCall(*sampleMaskWriteFunc, args);
        TIntermBlock *callBlock = new TIntermBlock;
        callBlock->appendStatement(callSampleMaskWriteFunc);
    
        TIntermSymbol *coverageMaskEnabled = new TIntermSymbol(coverageMaskEnabledVar);
        TIntermIfElse *ifCall              = new TIntermIfElse(coverageMaskEnabled, callBlock, nullptr);
    
        return RunAtTheEndOfShader(this, root, ifCall, symbolTable);
    }
    
    ANGLE_NO_DISCARD bool TranslatorMetal::insertRasterizerDiscardLogic(TIntermBlock *root)
    {
        TInfoSinkBase &sink       = getInfoSink().obj;
        TSymbolTable *symbolTable = &getSymbolTable();
    
        // Insert rasterizationDisabled specialization constant.
        sink << "layout (constant_id=0) const bool " << mtl::kRasterizerDiscardEnabledConstName;
        sink << " = false;\n";
    
        // Create kRasterizerDiscardEnabledConstName variable reference.
        TType *boolType = new TType(EbtBool);
        boolType->setQualifier(EvqConst);
        TVariable *discardEnabledVar =
            new TVariable(symbolTable, ImmutableString(mtl::kRasterizerDiscardEnabledConstName),
                          boolType, SymbolType::AngleInternal);
    
        // Insert this code to the end of main()
        // if (ANGLERasterizerDisabled)
        // {
        //      gl_Position = vec4(-3.0, -3.0, -3.0, 1.0);
        // }
        // Create a symbol reference to "gl_Position"
        const TVariable *position  = BuiltInVariable::gl_Position();
        TIntermSymbol *positionRef = new TIntermSymbol(position);
    
        // Create vec4(-3, -3, -3, 1):
        auto vec4Type             = new TType(EbtFloat, 4);
        TIntermSequence *vec4Args = new TIntermSequence();
        vec4Args->push_back(CreateFloatNode(-3.0f));
        vec4Args->push_back(CreateFloatNode(-3.0f));
        vec4Args->push_back(CreateFloatNode(-3.0f));
        vec4Args->push_back(CreateFloatNode(1.0f));
        TIntermAggregate *constVarConstructor =
            TIntermAggregate::CreateConstructor(*vec4Type, vec4Args);
    
        // Create the assignment "gl_Position = vec4(-3, -3, -3, 1)"
        TIntermBinary *assignment =
            new TIntermBinary(TOperator::EOpAssign, positionRef->deepCopy(), constVarConstructor);
    
        TIntermBlock *discardBlock = new TIntermBlock;
        discardBlock->appendStatement(assignment);
    
        TIntermSymbol *discardEnabled = new TIntermSymbol(discardEnabledVar);
        TIntermIfElse *ifCall         = new TIntermIfElse(discardEnabled, discardBlock, nullptr);
    
        return RunAtTheEndOfShader(this, root, ifCall, symbolTable);
    }
    
    }  // namespace sh