darling-JavaScriptCore/dfg/DFGUnificationPhase.cpp
2017-08-12 09:48:01 -07:00

95 lines
3.6 KiB
C++

/*
* Copyright (C) 2013, 2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "DFGUnificationPhase.h"
#if ENABLE(DFG_JIT)
#include "DFGBasicBlockInlines.h"
#include "DFGGraph.h"
#include "DFGPhase.h"
#include "JSCInlines.h"
namespace JSC { namespace DFG {
class UnificationPhase : public Phase {
public:
UnificationPhase(Graph& graph)
: Phase(graph, "unification")
{
}
bool run()
{
ASSERT(m_graph.m_form == ThreadedCPS);
ASSERT(m_graph.m_unificationState == LocallyUnified);
// Ensure that all Phi functions are unified.
for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
BasicBlock* block = m_graph.block(blockIndex);
if (!block)
continue;
ASSERT(block->isReachable);
for (unsigned phiIndex = block->phis.size(); phiIndex--;) {
Node* phi = block->phis[phiIndex];
for (unsigned childIdx = 0; childIdx < AdjacencyList::Size; ++childIdx) {
if (!phi->children.child(childIdx))
break;
// FIXME: Consider reversing the order of this unification, since the other
// order will reveal more bugs. https://bugs.webkit.org/show_bug.cgi?id=154368
phi->variableAccessData()->unify(phi->children.child(childIdx)->variableAccessData());
}
}
}
// Ensure that all predictions are fixed up based on the unification.
for (unsigned i = 0; i < m_graph.m_variableAccessData.size(); ++i) {
VariableAccessData* data = &m_graph.m_variableAccessData[i];
data->find()->predict(data->nonUnifiedPrediction());
data->find()->mergeStructureCheckHoistingFailed(data->structureCheckHoistingFailed());
data->find()->mergeCheckArrayHoistingFailed(data->checkArrayHoistingFailed());
data->find()->mergeShouldNeverUnbox(data->shouldNeverUnbox());
data->find()->mergeIsLoadedFrom(data->isLoadedFrom());
data->find()->mergeIsProfitableToUnbox(data->isProfitableToUnbox());
}
m_graph.m_unificationState = GloballyUnified;
return true;
}
};
bool performUnification(Graph& graph)
{
return runPhase<UnificationPhase>(graph);
}
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)