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/*
* Copyright (C) 2013-2019 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 "DFGWatchpointCollectionPhase.h"
#if ENABLE(DFG_JIT)
#include "DFGGraph.h"
#include "DFGPhase.h"
#include "JSCJSValueInlines.h"
// FIXME: Remove this phase entirely by moving the addLazily() calls into either the backend or
// into the phase that performs the optimization. Moving the calls into the backend makes the most
// sense when the intermediate phases don't need to know that the watchpoint was set. Moving the
// calls earlier usually only makes sense if the node's only purpose was to convey the need for
// the watchpoint (like VarInjectionWatchpoint). But, it can also make sense if the fact that the
// watchpoint was set enables other optimizations.
// https://bugs.webkit.org/show_bug.cgi?id=144669
namespace JSC { namespace DFG {
class WatchpointCollectionPhase : public Phase {
static constexpr bool verbose = false;
public:
WatchpointCollectionPhase(Graph& graph)
: Phase(graph, "watchpoint collection")
{
}
bool run()
{
for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
BasicBlock* block = m_graph.block(blockIndex);
if (!block)
continue;
for (unsigned nodeIndex = block->size(); nodeIndex--;) {
m_node = block->at(nodeIndex);
handle();
}
}
return true;
}
private:
void handle()
{
switch (m_node->op()) {
case TypeOfIsUndefined:
handleMasqueradesAsUndefined();
break;
case CompareEq:
if (m_node->isBinaryUseKind(ObjectUse)
|| (m_node->child1().useKind() == ObjectUse && m_node->child2().useKind() == ObjectOrOtherUse)
|| (m_node->child1().useKind() == ObjectOrOtherUse && m_node->child2().useKind() == ObjectUse)
|| (m_node->child1().useKind() == KnownOtherUse || m_node->child2().useKind() == KnownOtherUse))
handleMasqueradesAsUndefined();
break;
case ToBoolean:
case LogicalNot:
case Branch:
switch (m_node->child1().useKind()) {
case ObjectOrOtherUse:
case UntypedUse:
handleMasqueradesAsUndefined();
break;
default:
break;
}
break;
default:
break;
}
}
void handleMasqueradesAsUndefined()
{
if (m_graph.masqueradesAsUndefinedWatchpointIsStillValid(m_node->origin.semantic))
addLazily(globalObject()->masqueradesAsUndefinedWatchpoint());
}
void addLazily(WatchpointSet* set)
{
m_graph.watchpoints().addLazily(set);
}
JSGlobalObject* globalObject()
{
return m_graph.globalObjectFor(m_node->origin.semantic);
}
Node* m_node;
};
bool performWatchpointCollection(Graph& graph)
{
return runPhase<WatchpointCollectionPhase>(graph);
}
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)