BuiltInFunctionEmulator.cpp

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Author : Olli Etuaho
Date : 2016-12-09 17:32:29
Hash : da9fb093
Message : Work around atan(y, x) bug on NVIDIA atan(y, x) is not always returning expected results on NVIDIA OpenGL drivers between versions 367 and 375. Work around this by emulating atan(y, x) using the regular atan(x) function. A fix to the driver is expected in a future release. It is most convenient to implement the vector atan(y, x) functions by using the scalar atan(y, x) function. Support for simple dependencies between emulated functions is added to BuiltInFunctionEmulator. In the current implementation one function is allowed to have at most one other function as its dependency. BUG=chromium:672380 TEST=angle_end2end_tests Change-Id: I9eba8b0b7979c7c7eaed353b264932e41830beb1 Reviewed-on: https://chromium-review.googlesource.com/419016 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>

src/compiler/translator/BuiltInFunctionEmulator.cpp

//
// Copyright (c) 2002-2011 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.
//

#include "angle_gl.h"
#include "compiler/translator/BuiltInFunctionEmulator.h"
#include "compiler/translator/SymbolTable.h"
#include "compiler/translator/Cache.h"

namespace sh
{

class BuiltInFunctionEmulator::BuiltInFunctionEmulationMarker : public TIntermTraverser
{
  public:
    BuiltInFunctionEmulationMarker(BuiltInFunctionEmulator &emulator)
        : TIntermTraverser(true, false, false), mEmulator(emulator)
    {
    }

    bool visitUnary(Visit visit, TIntermUnary *node) override
    {
        if (visit == PreVisit)
        {
            bool needToEmulate =
                mEmulator.SetFunctionCalled(node->getOp(), node->getOperand()->getType());
            if (needToEmulate)
                node->setUseEmulatedFunction();
        }
        return true;
    }

    bool visitAggregate(Visit visit, TIntermAggregate *node) override
    {
        if (visit == PreVisit)
        {
            // Here we handle all the built-in functions instead of the ones we
            // currently identified as problematic.
            switch (node->getOp())
            {
                case EOpLessThan:
                case EOpGreaterThan:
                case EOpLessThanEqual:
                case EOpGreaterThanEqual:
                case EOpVectorEqual:
                case EOpVectorNotEqual:
                case EOpMod:
                case EOpPow:
                case EOpAtan:
                case EOpMin:
                case EOpMax:
                case EOpClamp:
                case EOpMix:
                case EOpStep:
                case EOpSmoothStep:
                case EOpDistance:
                case EOpDot:
                case EOpCross:
                case EOpFaceForward:
                case EOpReflect:
                case EOpRefract:
                case EOpOuterProduct:
                case EOpMul:
                    break;
                default:
                    return true;
            }
            const TIntermSequence &sequence = *(node->getSequence());
            bool needToEmulate              = false;
            // Right now we only handle built-in functions with two or three parameters.
            if (sequence.size() == 2)
            {
                TIntermTyped *param1 = sequence[0]->getAsTyped();
                TIntermTyped *param2 = sequence[1]->getAsTyped();
                if (!param1 || !param2)
                    return true;
                needToEmulate = mEmulator.SetFunctionCalled(node->getOp(), param1->getType(),
                                                            param2->getType());
            }
            else if (sequence.size() == 3)
            {
                TIntermTyped *param1 = sequence[0]->getAsTyped();
                TIntermTyped *param2 = sequence[1]->getAsTyped();
                TIntermTyped *param3 = sequence[2]->getAsTyped();
                if (!param1 || !param2 || !param3)
                    return true;
                needToEmulate = mEmulator.SetFunctionCalled(node->getOp(), param1->getType(),
                                                            param2->getType(), param3->getType());
            }
            else
            {
                return true;
            }

            if (needToEmulate)
                node->setUseEmulatedFunction();
        }
        return true;
    }

  private:
    BuiltInFunctionEmulator &mEmulator;
};

BuiltInFunctionEmulator::BuiltInFunctionEmulator()
{
}

BuiltInFunctionEmulator::FunctionId BuiltInFunctionEmulator::addEmulatedFunction(
    TOperator op,
    const TType *param,
    const char *emulatedFunctionDefinition)
{
    FunctionId id(op, param);
    mEmulatedFunctions[id] = std::string(emulatedFunctionDefinition);
    return id;
}

BuiltInFunctionEmulator::FunctionId BuiltInFunctionEmulator::addEmulatedFunction(
    TOperator op,
    const TType *param1,
    const TType *param2,
    const char *emulatedFunctionDefinition)
{
    FunctionId id(op, param1, param2);
    mEmulatedFunctions[id] = std::string(emulatedFunctionDefinition);
    return id;
}

BuiltInFunctionEmulator::FunctionId BuiltInFunctionEmulator::addEmulatedFunctionWithDependency(
    FunctionId dependency,
    TOperator op,
    const TType *param1,
    const TType *param2,
    const char *emulatedFunctionDefinition)
{
    FunctionId id(op, param1, param2);
    mEmulatedFunctions[id]    = std::string(emulatedFunctionDefinition);
    mFunctionDependencies[id] = dependency;
    return id;
}

BuiltInFunctionEmulator::FunctionId BuiltInFunctionEmulator::addEmulatedFunction(
    TOperator op,
    const TType *param1,
    const TType *param2,
    const TType *param3,
    const char *emulatedFunctionDefinition)
{
    FunctionId id(op, param1, param2, param3);
    mEmulatedFunctions[id] = std::string(emulatedFunctionDefinition);
    return id;
}

bool BuiltInFunctionEmulator::IsOutputEmpty() const
{
    return (mFunctions.size() == 0);
}

void BuiltInFunctionEmulator::OutputEmulatedFunctions(TInfoSinkBase &out) const
{
    for (size_t i = 0; i < mFunctions.size(); ++i)
    {
        out << mEmulatedFunctions.find(mFunctions[i])->second << "\n\n";
    }
}

bool BuiltInFunctionEmulator::SetFunctionCalled(TOperator op, const TType &param)
{
    return SetFunctionCalled(FunctionId(op, &param));
}

bool BuiltInFunctionEmulator::SetFunctionCalled(TOperator op,
                                                const TType &param1,
                                                const TType &param2)
{
    return SetFunctionCalled(FunctionId(op, &param1, &param2));
}

bool BuiltInFunctionEmulator::SetFunctionCalled(TOperator op,
                                                const TType &param1,
                                                const TType &param2,
                                                const TType &param3)
{
    return SetFunctionCalled(FunctionId(op, &param1, &param2, &param3));
}

bool BuiltInFunctionEmulator::SetFunctionCalled(const FunctionId &functionId)
{
    if (mEmulatedFunctions.find(functionId) != mEmulatedFunctions.end())
    {
        for (size_t i = 0; i < mFunctions.size(); ++i)
        {
            if (mFunctions[i] == functionId)
                return true;
        }
        // If the function depends on another, mark the dependency as called.
        auto dependency = mFunctionDependencies.find(functionId);
        if (dependency != mFunctionDependencies.end())
        {
            SetFunctionCalled((*dependency).second);
        }
        // Copy the functionId if it needs to be stored, to make sure that the TType pointers inside
        // remain valid and constant.
        mFunctions.push_back(functionId.getCopy());
        return true;
    }
    return false;
}

void BuiltInFunctionEmulator::MarkBuiltInFunctionsForEmulation(TIntermNode *root)
{
    ASSERT(root);

    if (mEmulatedFunctions.empty())
        return;

    BuiltInFunctionEmulationMarker marker(*this);
    root->traverse(&marker);
}

void BuiltInFunctionEmulator::Cleanup()
{
    mFunctions.clear();
    mFunctionDependencies.clear();
}

// static
TString BuiltInFunctionEmulator::GetEmulatedFunctionName(const TString &name)
{
    ASSERT(name[name.length() - 1] == '(');
    return "webgl_" + name.substr(0, name.length() - 1) + "_emu(";
}

BuiltInFunctionEmulator::FunctionId::FunctionId()
    : mOp(EOpNull),
      mParam1(TCache::getType(EbtVoid)),
      mParam2(TCache::getType(EbtVoid)),
      mParam3(TCache::getType(EbtVoid))
{
}

BuiltInFunctionEmulator::FunctionId::FunctionId(TOperator op, const TType *param)
    : mOp(op), mParam1(param), mParam2(TCache::getType(EbtVoid)), mParam3(TCache::getType(EbtVoid))
{
}

BuiltInFunctionEmulator::FunctionId::FunctionId(TOperator op,
                                                const TType *param1,
                                                const TType *param2)
    : mOp(op), mParam1(param1), mParam2(param2), mParam3(TCache::getType(EbtVoid))
{
}

BuiltInFunctionEmulator::FunctionId::FunctionId(TOperator op,
                                                const TType *param1,
                                                const TType *param2,
                                                const TType *param3)
    : mOp(op), mParam1(param1), mParam2(param2), mParam3(param3)
{
}

bool BuiltInFunctionEmulator::FunctionId::operator==(
    const BuiltInFunctionEmulator::FunctionId &other) const
{
    return (mOp == other.mOp && *mParam1 == *other.mParam1 && *mParam2 == *other.mParam2 &&
            *mParam3 == *other.mParam3);
}

bool BuiltInFunctionEmulator::FunctionId::operator<(
    const BuiltInFunctionEmulator::FunctionId &other) const
{
    if (mOp != other.mOp)
        return mOp < other.mOp;
    if (*mParam1 != *other.mParam1)
        return *mParam1 < *other.mParam1;
    if (*mParam2 != *other.mParam2)
        return *mParam2 < *other.mParam2;
    if (*mParam3 != *other.mParam3)
        return *mParam3 < *other.mParam3;
    return false;  // all fields are equal
}

BuiltInFunctionEmulator::FunctionId BuiltInFunctionEmulator::FunctionId::getCopy() const
{
    return FunctionId(mOp, new TType(*mParam1), new TType(*mParam2), new TType(*mParam3));
}

}  // namespace sh

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

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