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//
// Copyright 2002 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 "compiler/translator/tree_ops/apple/UnfoldShortCircuitAST.h"
#include "compiler/translator/IntermNode.h"
#include "compiler/translator/tree_util/IntermNode_util.h"
#include "compiler/translator/tree_util/IntermTraverse.h"
namespace sh
{
namespace
{
// "x || y" is equivalent to "x ? true : y".
TIntermTernary *UnfoldOR(TIntermTyped *x, TIntermTyped *y)
{
return new TIntermTernary(x, CreateBoolNode(true), y);
}
// "x && y" is equivalent to "x ? y : false".
TIntermTernary *UnfoldAND(TIntermTyped *x, TIntermTyped *y)
{
return new TIntermTernary(x, y, CreateBoolNode(false));
}
// This traverser identifies all the short circuit binary nodes that need to
// be replaced, and creates the corresponding replacement nodes. However,
// the actual replacements happen after the traverse through updateTree().
class UnfoldShortCircuitASTTraverser : public TIntermTraverser
{
public:
UnfoldShortCircuitASTTraverser() : TIntermTraverser(true, false, false) {}
bool visitBinary(Visit visit, TIntermBinary *) override;
};
bool UnfoldShortCircuitASTTraverser::visitBinary(Visit visit, TIntermBinary *node)
{
TIntermTernary *replacement = nullptr;
switch (node->getOp())
{
case EOpLogicalOr:
replacement = UnfoldOR(node->getLeft(), node->getRight());
break;
case EOpLogicalAnd:
replacement = UnfoldAND(node->getLeft(), node->getRight());
break;
default:
break;
}
if (replacement)
{
queueReplacement(replacement, OriginalNode::IS_DROPPED);
}
return true;
}
} // anonymous namespace
bool UnfoldShortCircuitAST(TCompiler *compiler, TIntermBlock *root)
{
UnfoldShortCircuitASTTraverser traverser;
root->traverse(&traverser);
return traverser.updateTree(compiler, root);
}
} // namespace sh
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