RewriteAtomicFunctionExpressions.cpp

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Author : Stuart Morgan
Date : 2019-08-14 12:25:12
Hash : 9d737966
Message : Standardize copyright notices to project style For all "ANGLE Project" copyrights, standardize to the format specified by the style guide. Changes: - "Copyright (c)" and "Copyright(c)" changed to just "Copyright". - Removed the second half of date ranges ("Y1Y1-Y2Y2"->"Y1Y1"). - Fixed a small number of files that had no copyright date using the initial commit year from the version control history. - Fixed one instance of copyright being "The ANGLE Project" rather than "The ANGLE Project Authors" These changes are applied both to the copyright of source file, and where applicable to copyright statements that are generated by templates. BUG=angleproject:3811 Change-Id: I973dd65e4ef9deeba232d5be74c768256a0eb2e5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1754397 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>

src/compiler/translator/tree_ops/RewriteAtomicFunctionExpressions.cpp

//
// Copyright 2018 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.
//
// Implementation of the function RewriteAtomicFunctionExpressions.
// See the header for more details.

#include "RewriteAtomicFunctionExpressions.h"

#include "compiler/translator/tree_util/IntermNodePatternMatcher.h"
#include "compiler/translator/tree_util/IntermNode_util.h"
#include "compiler/translator/tree_util/IntermTraverse.h"
#include "compiler/translator/util.h"

namespace sh
{
namespace
{
// Traverser that simplifies all the atomic function expressions into the ones that can be directly
// translated into HLSL.
//
// case 1 (only for atomicExchange and atomicCompSwap):
//  original:
//      atomicExchange(counter, newValue);
//  new:
//      tempValue = atomicExchange(counter, newValue);
//
// case 2 (atomic function, temporary variable required):
//  original:
//      value = atomicAdd(counter, 1) * otherValue;
//      someArray[atomicAdd(counter, 1)] = someOtherValue;
//  new:
//      value = ((tempValue = atomicAdd(counter, 1)), tempValue) * otherValue;
//      someArray[((tempValue = atomicAdd(counter, 1)), tempValue)] = someOtherValue;
//
// case 3 (atomic function used directly initialize a variable):
//  original:
//      int value = atomicAdd(counter, 1);
//  new:
//      tempValue = atomicAdd(counter, 1);
//      int value = tempValue;
//
class RewriteAtomicFunctionExpressionsTraverser : public TIntermTraverser
{
  public:
    RewriteAtomicFunctionExpressionsTraverser(TSymbolTable *symbolTable, int shaderVersion);

    bool visitAggregate(Visit visit, TIntermAggregate *node) override;
    bool visitBlock(Visit visit, TIntermBlock *node) override;

  private:
    static bool IsAtomicExchangeOrCompSwapNoReturnValue(TIntermAggregate *node,
                                                        TIntermNode *parentNode);
    static bool IsAtomicFunctionInsideExpression(TIntermAggregate *node, TIntermNode *parentNode);

    void rewriteAtomicFunctionCallNode(TIntermAggregate *oldAtomicFunctionNode);

    const TVariable *getTempVariable(const TType *type);

    int mShaderVersion;
    TIntermSequence mTempVariables;
};

RewriteAtomicFunctionExpressionsTraverser::RewriteAtomicFunctionExpressionsTraverser(
    TSymbolTable *symbolTable,
    int shaderVersion)
    : TIntermTraverser(false, false, true, symbolTable), mShaderVersion(shaderVersion)
{}

void RewriteAtomicFunctionExpressionsTraverser::rewriteAtomicFunctionCallNode(
    TIntermAggregate *oldAtomicFunctionNode)
{
    ASSERT(oldAtomicFunctionNode);

    const TVariable *returnVariable = getTempVariable(&oldAtomicFunctionNode->getType());

    TIntermBinary *rewrittenNode = new TIntermBinary(
        TOperator::EOpAssign, CreateTempSymbolNode(returnVariable), oldAtomicFunctionNode);

    auto *parentNode = getParentNode();

    auto *parentBinary = parentNode->getAsBinaryNode();
    if (parentBinary && parentBinary->getOp() == EOpInitialize)
    {
        insertStatementInParentBlock(rewrittenNode);
        queueReplacement(CreateTempSymbolNode(returnVariable), OriginalNode::IS_DROPPED);
    }
    else
    {
        // As all atomic function assignment will be converted to the last argument of an
        // interlocked function, if we need the return value, assignment needs to be wrapped with
        // the comma operator and the temporary variables.
        if (!parentNode->getAsBlock())
        {
            rewrittenNode = TIntermBinary::CreateComma(
                rewrittenNode, new TIntermSymbol(returnVariable), mShaderVersion);
        }

        queueReplacement(rewrittenNode, OriginalNode::IS_DROPPED);
    }
}

const TVariable *RewriteAtomicFunctionExpressionsTraverser::getTempVariable(const TType *type)
{
    TIntermDeclaration *variableDeclaration;
    TVariable *returnVariable =
        DeclareTempVariable(mSymbolTable, type, EvqTemporary, &variableDeclaration);
    mTempVariables.push_back(variableDeclaration);
    return returnVariable;
}

bool RewriteAtomicFunctionExpressionsTraverser::IsAtomicExchangeOrCompSwapNoReturnValue(
    TIntermAggregate *node,
    TIntermNode *parentNode)
{
    ASSERT(node);
    return (node->getOp() == EOpAtomicExchange || node->getOp() == EOpAtomicCompSwap) &&
           parentNode && parentNode->getAsBlock();
}

bool RewriteAtomicFunctionExpressionsTraverser::IsAtomicFunctionInsideExpression(
    TIntermAggregate *node,
    TIntermNode *parentNode)
{
    ASSERT(node);
    // We only need to handle atomic functions with a parent that it is not block nodes. If the
    // parent node is block, it means that the atomic function is not inside an expression.
    if (!IsAtomicFunction(node->getOp()) || parentNode->getAsBlock())
    {
        return false;
    }

    auto *parentAsBinary = parentNode->getAsBinaryNode();
    // Assignments are handled in OutputHLSL
    return !parentAsBinary || parentAsBinary->getOp() != EOpAssign;
}

bool RewriteAtomicFunctionExpressionsTraverser::visitAggregate(Visit visit, TIntermAggregate *node)
{
    ASSERT(visit == PostVisit);
    // Skip atomic memory functions for SSBO. They will be processed in the OutputHLSL traverser.
    if (IsAtomicFunction(node->getOp()) &&
        IsInShaderStorageBlock((*node->getSequence())[0]->getAsTyped()))
    {
        return false;
    }

    TIntermNode *parentNode = getParentNode();
    if (IsAtomicExchangeOrCompSwapNoReturnValue(node, parentNode) ||
        IsAtomicFunctionInsideExpression(node, parentNode))
    {
        rewriteAtomicFunctionCallNode(node);
    }

    return true;
}

bool RewriteAtomicFunctionExpressionsTraverser::visitBlock(Visit visit, TIntermBlock *node)
{
    ASSERT(visit == PostVisit);

    if (!mTempVariables.empty() && getParentNode()->getAsFunctionDefinition())
    {
        insertStatementsInBlockAtPosition(node, 0, mTempVariables, TIntermSequence());
        mTempVariables.clear();
    }

    return true;
}

}  // anonymous namespace

void RewriteAtomicFunctionExpressions(TIntermNode *root,
                                      TSymbolTable *symbolTable,
                                      int shaderVersion)
{
    RewriteAtomicFunctionExpressionsTraverser traverser(symbolTable, shaderVersion);
    traverser.traverse(root);
    traverser.updateTree();
}
}  // namespace sh

kc3-lang/angle/src/compiler/translator/tree_ops/RewriteAtomicFunctionExpressions.cpp

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kc3-lang/angle /src/compiler/translator/tree_ops/RewriteAtomicFunctionExpressions.cpp