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/*
* Copyright (C) 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 "DFGClobbersExitState.h"
#if ENABLE(DFG_JIT)
#include "ButterflyInlines.h"
#include "DFGClobberize.h"
#include "DFGNode.h"
namespace JSC { namespace DFG {
bool clobbersExitState(Graph& graph, Node* node)
{
// There are certain nodes whose effect on the exit state has nothing to do with what they
// normally clobber.
switch (node->op()) {
case InitializeEntrypointArguments:
case MovHint:
case ZombieHint:
case PutHint:
case KillStack:
return true;
case SetLocal:
case PutStack:
// These nodes write to the stack, but they may only do so after we have already had a MovHint
// for the exact same value and the same stack location. Hence, they have no further effect on
// exit state.
return false;
case ArrayifyToStructure:
case Arrayify:
case NewObject:
case NewGenerator:
case NewAsyncGenerator:
case NewInternalFieldObject:
case NewRegExp:
case NewMap:
case NewSet:
case NewStringObject:
case NewBoundFunction:
case PhantomNewObject:
case MaterializeNewObject:
case PhantomNewFunction:
case PhantomNewGeneratorFunction:
case PhantomNewAsyncGeneratorFunction:
case PhantomNewAsyncFunction:
case PhantomNewInternalFieldObject:
case MaterializeNewInternalFieldObject:
case PhantomCreateActivation:
case MaterializeCreateActivation:
case PhantomNewRegExp:
case CountExecution:
case SuperSamplerBegin:
case SuperSamplerEnd:
case StoreBarrier:
case FencedStoreBarrier:
case AllocatePropertyStorage:
case ReallocatePropertyStorage:
case FilterCallLinkStatus:
case FilterGetByStatus:
case FilterPutByStatus:
case FilterInByStatus:
case FilterDeleteByStatus:
case FilterCheckPrivateBrandStatus:
case FilterSetPrivateBrandStatus:
case TryGetById:
// These do clobber memory, but nothing that is observable. It may be nice to separate the
// heaps into those that are observable and those that aren't, but we don't do that right now.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=148440
return false;
case NewRegExpUntyped:
return !(node->child1().useKind() == StringUse && node->child2().useKind() == StringUse);
case CreateActivation:
// Like above, but with the activation allocation caveat.
return node->castOperand<SymbolTable*>()->singleton().isStillValid();
case NewFunction:
case NewGeneratorFunction:
case NewAsyncGeneratorFunction:
case NewAsyncFunction:
// Like above, but with the JSFunction allocation caveat.
return node->castOperand<FunctionExecutable*>()->singleton().isStillValid();
default:
// For all other nodes, we just care about whether they write to something other than SideState.
bool result = false;
clobberize(
graph, node, NoOpClobberize(),
[&] (const AbstractHeap& heap) {
// There shouldn't be such a thing as a strict subtype of SideState or HeapObjectCount.
// That's what allows us to use a fast != check, below.
ASSERT(!heap.isStrictSubtypeOf(SideState) && !heap.isStrictSubtypeOf(HeapObjectCount));
if (heap != SideState && heap != HeapObjectCount)
result = true;
},
NoOpClobberize());
return result;
}
}
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
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