chromium/third_party/angle/src/compiler/translator/tree_ops/SimplifyLoopConditions.cpp

//
// Copyright 2016 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.
//
// SimplifyLoopConditions is an AST traverser that converts loop conditions and loop expressions
// to regular statements inside the loop. This way further transformations that generate statements
// from loop conditions and loop expressions work correctly.
//

#include "compiler/translator/tree_ops/SimplifyLoopConditions.h"

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

namespace sh
{

namespace
{

struct LoopInfo
{ … };

class SimplifyLoopConditionsTraverser : public TLValueTrackingTraverser
{ … };

SimplifyLoopConditionsTraverser::SimplifyLoopConditionsTraverser(
    const IntermNodePatternMatcher *conditionsToSimplify,
    TSymbolTable *symbolTable)
    : … { … }

// If we're inside a loop initialization, condition, or expression, we check for expressions that
// should be moved out of the loop condition or expression. If one is found, the loop is
// transformed.
// If we're not inside loop initialization, condition, or expression, we only need to traverse nodes
// that may contain loops.

bool SimplifyLoopConditionsTraverser::visitUnary(Visit visit, TIntermUnary *node)
{ … }

bool SimplifyLoopConditionsTraverser::visitBinary(Visit visit, TIntermBinary *node)
{ … }

bool SimplifyLoopConditionsTraverser::visitAggregate(Visit visit, TIntermAggregate *node)
{ … }

bool SimplifyLoopConditionsTraverser::visitTernary(Visit visit, TIntermTernary *node)
{ … }

bool SimplifyLoopConditionsTraverser::visitDeclaration(Visit visit, TIntermDeclaration *node)
{ … }

bool SimplifyLoopConditionsTraverser::visitBranch(Visit visit, TIntermBranch *node)
{ … }

static TIntermBlock *CreateFromBody(TIntermLoop *node, bool *bodyEndsInBranchOut)
{ … }

void SimplifyLoopConditionsTraverser::traverseLoop(TIntermLoop *node)
{ … }

}  // namespace

bool SimplifyLoopConditions(TCompiler *compiler, TIntermNode *root, TSymbolTable *symbolTable)
{ … }

bool SimplifyLoopConditions(TCompiler *compiler,
                            TIntermNode *root,
                            unsigned int conditionsToSimplifyMask,
                            TSymbolTable *symbolTable)
{ … }

}  // namespace sh