Source/JavaScriptCore/dfg/DFGDoesGC.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2014-2019 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 "DFGDoesGC.h"

 #if ENABLE(DFG_JIT)

 #include "DFGClobberize.h"
 #include "DFGGraph.h"
 #include "DFGNode.h"
 #include "Operations.h"

 namespace JSC { namespace DFG {

 bool doesGC(Graph& graph, Node* node)
 {
     if (clobbersHeap(graph, node))
         return true;

     // Now consider nodes that don't clobber the world but that still may GC. This includes all
     // nodes. By default, we should assume every node can GC and return true. This includes the
     // world-clobbering nodes. We should only return false if we have proven that the node cannot
     // GC. Typical examples of how a node can GC is if the code emitted for the node does any of the
     // following:
     //     1. Allocates any objects.
     //     2. Resolves a rope string, which allocates a string.
     //     3. Produces a string (which allocates the string) except when we can prove that
     //        the string will always be one of the pre-allcoated SmallStrings.
     //     4. Triggers a structure transition (which can allocate a new structure)
     //        unless it is a known transition between previously allocated structures
     //        such as between Array types.
     //     5. Calls to a JS function, which can execute arbitrary code including allocating objects.
     //     6. Calls operations that uses DeferGC, because it may GC in its destructor.

     switch (node->op()) {
     case JSConstant:
     case DoubleConstant:
     case Int52Constant:
     case LazyJSConstant:
     case Identity:
     case IdentityWithProfile:
     case GetCallee:
     case SetCallee:
     case GetArgumentCountIncludingThis:
     case SetArgumentCountIncludingThis:
     case GetRestLength:
     case GetLocal:
     case SetLocal:
     case MovHint:
     case InitializeEntrypointArguments:
     case ZombieHint:
     case ExitOK:
     case Phantom:
     case Upsilon:
     case Phi:
     case Flush:
     case PhantomLocal:
     case SetArgumentDefinitely:
     case SetArgumentMaybe:
     case ArithBitNot:
     case ArithBitAnd:
     case ArithBitOr:
     case ArithBitXor:
     case ArithBitLShift:
     case ArithBitRShift:
     case BitURShift:
     case ValueToInt32:
     case UInt32ToNumber:
     case DoubleAsInt32:
     case ArithAdd:
     case ArithClz32:
     case ArithSub:
     case ArithNegate:
     case ArithMul:
     case ArithIMul:
     case ArithDiv:
     case ArithMod:
     case ArithAbs:
     case ArithMin:
     case ArithMax:
     case ArithPow:
     case ArithSqrt:
     case ArithRandom:
     case ArithRound:
     case ArithFloor:
     case ArithCeil:
     case ArithTrunc:
     case ArithFRound:
     case ArithUnary:
     case CheckStructure:
     case CheckStructureOrEmpty:
     case CheckStructureImmediate:
     case GetExecutable:
     case GetButterfly:
     case CheckSubClass:
     case CheckArray:
     case GetScope:
     case SkipScope:
     case GetGlobalObject:
     case GetGlobalThis:
     case GetClosureVar:
     case PutClosureVar:
     case GetInternalField:
     case PutInternalField:
     case GetRegExpObjectLastIndex:
     case SetRegExpObjectLastIndex:
     case RecordRegExpCachedResult:
     case GetGlobalVar:
     case GetGlobalLexicalVariable:
     case PutGlobalVariable:
     case CheckCell:
     case CheckNotEmpty:
     case AssertNotEmpty:
     case CheckStringIdent:
     case CompareBelow:
     case CompareBelowEq:
     case CompareEqPtr:
     case ProfileControlFlow:
     case OverridesHasInstance:
     case IsEmpty:
     case IsUndefined:
     case IsUndefinedOrNull:
     case IsBoolean:
     case IsNumber:
     case NumberIsInteger:
     case IsObject:
     case IsObjectOrNull:
     case IsFunction:
     case IsCellWithType:
     case IsTypedArrayView:
     case TypeOf:
     case LogicalNot:
     case Jump:
     case Branch:
     case EntrySwitch:
     case CountExecution:
     case SuperSamplerBegin:
     case SuperSamplerEnd:
     case CPUIntrinsic:
     case NormalizeMapKey:
     case GetMapBucketHead:
     case GetMapBucketNext:
     case LoadKeyFromMapBucket:
     case LoadValueFromMapBucket:
     case ExtractValueFromWeakMapGet:
     case WeakMapGet:
     case WeakSetAdd:
     case WeakMapSet:
     case Unreachable:
     case ExtractOSREntryLocal:
     case ExtractCatchLocal:
     case ClearCatchLocals:
     case LoopHint:
     case StoreBarrier:
     case FencedStoreBarrier:
     case InvalidationPoint:
     case NotifyWrite:
     case CheckInBounds:
     case ConstantStoragePointer:
     case Check:
     case CheckVarargs:
     case CheckTypeInfoFlags:
     case MultiGetByOffset:
     case ValueRep:
     case DoubleRep:
     case Int52Rep:
     case GetGetter:
     case GetSetter:
     case GetArrayLength:
     case GetVectorLength:
     case StringCharCodeAt:
     case StringCodePointAt:
     case GetTypedArrayByteOffset:
     case GetPrototypeOf:
     case PutStructure:
     case GetByOffset:
     case GetGetterSetterByOffset:
     case GetEnumerableLength:
     case FiatInt52:
     case BooleanToNumber:
     case CheckBadCell:
     case BottomValue:
     case PhantomNewObject:
     case PhantomNewFunction:
     case PhantomNewGeneratorFunction:
     case PhantomNewAsyncFunction:
     case PhantomNewAsyncGeneratorFunction:
     case PhantomCreateActivation:
     case PhantomDirectArguments:
     case PhantomCreateRest:
     case PhantomNewArrayWithSpread:
     case PhantomNewArrayBuffer:
     case PhantomSpread:
     case PhantomClonedArguments:
     case PhantomNewRegexp:
     case GetMyArgumentByVal:
     case GetMyArgumentByValOutOfBounds:
     case ForwardVarargs:
     case PutHint:
     case KillStack:
     case GetStack:
     case GetFromArguments:
     case GetArgument:
     case LogShadowChickenPrologue:
     case LogShadowChickenTail:
     case NukeStructureAndSetButterfly:
     case AtomicsAdd:
     case AtomicsAnd:
     case AtomicsCompareExchange:
     case AtomicsExchange:
     case AtomicsLoad:
     case AtomicsOr:
     case AtomicsStore:
     case AtomicsSub:
     case AtomicsXor:
     case AtomicsIsLockFree:
     case MatchStructure:
     case FilterCallLinkStatus:
     case FilterGetByIdStatus:
     case FilterPutByIdStatus:
     case FilterInByIdStatus:
     case DateGetInt32OrNaN:
     case DateGetTime:
     case DataViewGetInt:
     case DataViewGetFloat:
     case DataViewSet:
         return false;

 #if !ASSERT_DISABLED
     case ArrayPush:
     case ArrayPop:
     case PushWithScope:
     case CreateActivation:
     case CreateDirectArguments:
     case CreateScopedArguments:
     case CreateClonedArguments:
     case Call:
     case CallEval:
     case CallForwardVarargs:
     case CallObjectConstructor:
     case CallVarargs:
     case CheckTierUpAndOSREnter:
     case CheckTierUpAtReturn:
     case CheckTierUpInLoop:
     case Construct:
     case ConstructForwardVarargs:
     case ConstructVarargs:
     case DefineDataProperty:
     case DefineAccessorProperty:
     case DeleteById:
     case DeleteByVal:
     case DirectCall:
     case DirectConstruct:
     case DirectTailCall:
     case DirectTailCallInlinedCaller:
     case ForceOSRExit:
     case GetById:
     case GetByIdDirect:
     case GetByIdDirectFlush:
     case GetByIdFlush:
     case GetByIdWithThis:
     case GetByValWithThis:
     case GetDirectPname:
     case GetDynamicVar:
     case GetMapBucket:
     case HasGenericProperty:
     case HasIndexedProperty:
     case HasOwnProperty:
     case HasStructureProperty:
     case InById:
     case InByVal:
     case InstanceOf:
     case InstanceOfCustom:
     case LoadVarargs:
     case NumberToStringWithRadix:
     case NumberToStringWithValidRadixConstant:
     case ProfileType:
     case PutById:
     case PutByIdDirect:
     case PutByIdFlush:
     case PutByIdWithThis:
     case PutByOffset:
     case PutByValWithThis:
     case PutDynamicVar:
     case PutGetterById:
     case PutGetterByVal:
     case PutGetterSetterById:
     case PutSetterById:
     case PutSetterByVal:
     case PutStack:
     case PutToArguments:
     case RegExpExec:
     case RegExpExecNonGlobalOrSticky:
     case RegExpMatchFast:
     case RegExpMatchFastGlobal:
     case RegExpTest:
     case ResolveScope:
     case ResolveScopeForHoistingFuncDeclInEval:
     case Return:
     case StringCharAt:
     case TailCall:
     case TailCallForwardVarargs:
     case TailCallForwardVarargsInlinedCaller:
     case TailCallInlinedCaller:
     case TailCallVarargs:
     case TailCallVarargsInlinedCaller:
     case Throw:
     case ToNumber:
     case ToObject:
     case ToPrimitive:
     case ToThis:
     case TryGetById:
     case CreateThis:
     case CreatePromise:
     case CreateGenerator:
     case CreateAsyncGenerator:
     case ObjectCreate:
     case ObjectKeys:
     case AllocatePropertyStorage:
     case ReallocatePropertyStorage:
     case Arrayify:
     case ArrayifyToStructure:
     case NewObject:
     case NewPromise:
     case NewGenerator:
     case NewAsyncGenerator:
     case NewArray:
     case NewArrayWithSpread:
     case Spread:
     case NewArrayWithSize:
     case NewArrayBuffer:
     case NewRegexp:
     case NewStringObject:
     case NewSymbol:
     case MakeRope:
     case NewFunction:
     case NewGeneratorFunction:
     case NewAsyncGeneratorFunction:
     case NewAsyncFunction:
     case NewTypedArray:
     case ThrowStaticError:
     case GetPropertyEnumerator:
     case GetEnumeratorStructurePname:
     case GetEnumeratorGenericPname:
     case ToIndexString:
     case MaterializeNewObject:
     case MaterializeCreateActivation:
     case SetFunctionName:
     case StrCat:
     case StringReplace:
     case StringReplaceRegExp:
     case StringSlice:
     case StringValueOf:
     case CreateRest:
     case ToLowerCase:
     case CallDOMGetter:
     case CallDOM:
     case ArraySlice:
     case ArrayIndexOf:
     case ParseInt: // We might resolve a rope even though we don't clobber anything.
     case SetAdd:
     case MapSet:
     case ValueBitAnd:
     case ValueBitOr:
     case ValueBitXor:
     case ValueBitLShift:
     case ValueBitRShift:
     case ValueAdd:
     case ValueSub:
     case ValueMul:
     case ValueDiv:
     case ValueMod:
     case ValuePow:
     case ValueBitNot:
     case ValueNegate:
 #else
     // See comment at the top for why be default for all nodes should be to
     // return true.
     default:
 #endif
         return true;

     case CallStringConstructor:
     case ToString:
         switch (node->child1().useKind()) {
         case StringObjectUse:
         case StringOrStringObjectUse:
             return false;
         default:
             break;
         }
         return true;

     case CheckTraps:
         // FIXME: https://bugs.webkit.org/show_bug.cgi?id=194323
         ASSERT(Options::usePollingTraps());
         return true;

     case CompareEq:
     case CompareLess:
     case CompareLessEq:
     case CompareGreater:
     case CompareGreaterEq:
         if (node->isBinaryUseKind(Int32Use)
 #if USE(JSVALUE64)
             || node->isBinaryUseKind(Int52RepUse)
 #endif
             || node->isBinaryUseKind(DoubleRepUse)
             || node->isBinaryUseKind(StringIdentUse)
             )
             return false;
         if (node->op() == CompareEq) {
             if (node->isBinaryUseKind(BooleanUse)
                 || node->isBinaryUseKind(SymbolUse)
                 || node->isBinaryUseKind(ObjectUse)
                 || node->isBinaryUseKind(ObjectUse, ObjectOrOtherUse) || node->isBinaryUseKind(ObjectOrOtherUse, ObjectUse))
                 return false;
         }
         return true;

     case CompareStrictEq:
         if (node->isBinaryUseKind(BooleanUse)
             || node->isBinaryUseKind(Int32Use)
 #if USE(JSVALUE64)
             || node->isBinaryUseKind(Int52RepUse)
 #endif
             || node->isBinaryUseKind(DoubleRepUse)
             || node->isBinaryUseKind(SymbolUse)
             || node->isBinaryUseKind(SymbolUse, UntypedUse)
             || node->isBinaryUseKind(UntypedUse, SymbolUse)
             || node->isBinaryUseKind(StringIdentUse)
             || node->isBinaryUseKind(ObjectUse, UntypedUse) || node->isBinaryUseKind(UntypedUse, ObjectUse)
             || node->isBinaryUseKind(ObjectUse)
             || node->isBinaryUseKind(MiscUse, UntypedUse) || node->isBinaryUseKind(UntypedUse, MiscUse)
             || node->isBinaryUseKind(StringIdentUse, NotStringVarUse) || node->isBinaryUseKind(NotStringVarUse, StringIdentUse))
             return false;
         return true;

     case GetIndexedPropertyStorage:
     case GetByVal:
         if (node->arrayMode().type() == Array::String)
             return true;
         return false;

     case PutByValDirect:
     case PutByVal:
     case PutByValAlias:
         if (!graph.m_plan.isFTL()) {
             switch (node->arrayMode().modeForPut().type()) {
             case Array::Int8Array:
             case Array::Int16Array:
             case Array::Int32Array:
             case Array::Uint8Array:
             case Array::Uint8ClampedArray:
             case Array::Uint16Array:
             case Array::Uint32Array:
                 return true;
             default:
                 break;
             }
         }
         return false;

     case MapHash:
         switch (node->child1().useKind()) {
         case BooleanUse:
         case Int32Use:
         case SymbolUse:
         case ObjectUse:
             return false;
         default:
             // We might resolve a rope.
             return true;
         }

     case MultiPutByOffset:
         return node->multiPutByOffsetData().reallocatesStorage();

     case SameValue:
         if (node->isBinaryUseKind(DoubleRepUse))
             return false;
         return true;

     case StringFromCharCode:
         // FIXME: Should we constant fold this case?
         // https://bugs.webkit.org/show_bug.cgi?id=194308
         if (node->child1()->isInt32Constant() && (node->child1()->asUInt32() <= maxSingleCharacterString))
             return false;
         return true;

     case Switch:
         switch (node->switchData()->kind) {
         case SwitchCell:
             ASSERT(graph.m_plan.isFTL());
             FALLTHROUGH;
         case SwitchImm:
             return false;
         case SwitchChar:
             return true;
         case SwitchString:
             if (node->child1().useKind() == StringIdentUse)
                 return false;
             ASSERT(node->child1().useKind() == StringUse || node->child1().useKind() == UntypedUse);
             return true;
         }
         RELEASE_ASSERT_NOT_REACHED();

     case LastNodeType:
         RELEASE_ASSERT_NOT_REACHED();
     }

     RELEASE_ASSERT_NOT_REACHED();
 }

 } } // namespace JSC::DFG

 #endif // ENABLE(DFG_JIT)
	/*
	* Copyright (C) 2014-2019 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 "DFGDoesGC.h"

	#if ENABLE(DFG_JIT)

	#include "DFGClobberize.h"
	#include "DFGGraph.h"
	#include "DFGNode.h"
	#include "Operations.h"

	namespace JSC { namespace DFG {

	bool doesGC(Graph& graph, Node* node)
	{
	if (clobbersHeap(graph, node))
	return true;

	// Now consider nodes that don't clobber the world but that still may GC. This includes all
	// nodes. By default, we should assume every node can GC and return true. This includes the
	// world-clobbering nodes. We should only return false if we have proven that the node cannot
	// GC. Typical examples of how a node can GC is if the code emitted for the node does any of the
	// following:
	// 1. Allocates any objects.
	// 2. Resolves a rope string, which allocates a string.
	// 3. Produces a string (which allocates the string) except when we can prove that
	// the string will always be one of the pre-allcoated SmallStrings.
	// 4. Triggers a structure transition (which can allocate a new structure)
	// unless it is a known transition between previously allocated structures
	// such as between Array types.
	// 5. Calls to a JS function, which can execute arbitrary code including allocating objects.
	// 6. Calls operations that uses DeferGC, because it may GC in its destructor.

	switch (node->op()) {
	case JSConstant:
	case DoubleConstant:
	case Int52Constant:
	case LazyJSConstant:
	case Identity:
	case IdentityWithProfile:
	case GetCallee:
	case SetCallee:
	case GetArgumentCountIncludingThis:
	case SetArgumentCountIncludingThis:
	case GetRestLength:
	case GetLocal:
	case SetLocal:
	case MovHint:
	case InitializeEntrypointArguments:
	case ZombieHint:
	case ExitOK:
	case Phantom:
	case Upsilon:
	case Phi:
	case Flush:
	case PhantomLocal:
	case SetArgumentDefinitely:
	case SetArgumentMaybe:
	case ArithBitNot:
	case ArithBitAnd:
	case ArithBitOr:
	case ArithBitXor:
	case ArithBitLShift:
	case ArithBitRShift:
	case BitURShift:
	case ValueToInt32:
	case UInt32ToNumber:
	case DoubleAsInt32:
	case ArithAdd:
	case ArithClz32:
	case ArithSub:
	case ArithNegate:
	case ArithMul:
	case ArithIMul:
	case ArithDiv:
	case ArithMod:
	case ArithAbs:
	case ArithMin:
	case ArithMax:
	case ArithPow:
	case ArithSqrt:
	case ArithRandom:
	case ArithRound:
	case ArithFloor:
	case ArithCeil:
	case ArithTrunc:
	case ArithFRound:
	case ArithUnary:
	case CheckStructure:
	case CheckStructureOrEmpty:
	case CheckStructureImmediate:
	case GetExecutable:
	case GetButterfly:
	case CheckSubClass:
	case CheckArray:
	case GetScope:
	case SkipScope:
	case GetGlobalObject:
	case GetGlobalThis:
	case GetClosureVar:
	case PutClosureVar:
	case GetInternalField:
	case PutInternalField:
	case GetRegExpObjectLastIndex:
	case SetRegExpObjectLastIndex:
	case RecordRegExpCachedResult:
	case GetGlobalVar:
	case GetGlobalLexicalVariable:
	case PutGlobalVariable:
	case CheckCell:
	case CheckNotEmpty:
	case AssertNotEmpty:
	case CheckStringIdent:
	case CompareBelow:
	case CompareBelowEq:
	case CompareEqPtr:
	case ProfileControlFlow:
	case OverridesHasInstance:
	case IsEmpty:
	case IsUndefined:
	case IsUndefinedOrNull:
	case IsBoolean:
	case IsNumber:
	case NumberIsInteger:
	case IsObject:
	case IsObjectOrNull:
	case IsFunction:
	case IsCellWithType:
	case IsTypedArrayView:
	case TypeOf:
	case LogicalNot:
	case Jump:
	case Branch:
	case EntrySwitch:
	case CountExecution:
	case SuperSamplerBegin:
	case SuperSamplerEnd:
	case CPUIntrinsic:
	case NormalizeMapKey:
	case GetMapBucketHead:
	case GetMapBucketNext:
	case LoadKeyFromMapBucket:
	case LoadValueFromMapBucket:
	case ExtractValueFromWeakMapGet:
	case WeakMapGet:
	case WeakSetAdd:
	case WeakMapSet:
	case Unreachable:
	case ExtractOSREntryLocal:
	case ExtractCatchLocal:
	case ClearCatchLocals:
	case LoopHint:
	case StoreBarrier:
	case FencedStoreBarrier:
	case InvalidationPoint:
	case NotifyWrite:
	case CheckInBounds:
	case ConstantStoragePointer:
	case Check:
	case CheckVarargs:
	case CheckTypeInfoFlags:
	case MultiGetByOffset:
	case ValueRep:
	case DoubleRep:
	case Int52Rep:
	case GetGetter:
	case GetSetter:
	case GetArrayLength:
	case GetVectorLength:
	case StringCharCodeAt:
	case StringCodePointAt:
	case GetTypedArrayByteOffset:
	case GetPrototypeOf:
	case PutStructure:
	case GetByOffset:
	case GetGetterSetterByOffset:
	case GetEnumerableLength:
	case FiatInt52:
	case BooleanToNumber:
	case CheckBadCell:
	case BottomValue:
	case PhantomNewObject:
	case PhantomNewFunction:
	case PhantomNewGeneratorFunction:
	case PhantomNewAsyncFunction:
	case PhantomNewAsyncGeneratorFunction:
	case PhantomCreateActivation:
	case PhantomDirectArguments:
	case PhantomCreateRest:
	case PhantomNewArrayWithSpread:
	case PhantomNewArrayBuffer:
	case PhantomSpread:
	case PhantomClonedArguments:
	case PhantomNewRegexp:
	case GetMyArgumentByVal:
	case GetMyArgumentByValOutOfBounds:
	case ForwardVarargs:
	case PutHint:
	case KillStack:
	case GetStack:
	case GetFromArguments:
	case GetArgument:
	case LogShadowChickenPrologue:
	case LogShadowChickenTail:
	case NukeStructureAndSetButterfly:
	case AtomicsAdd:
	case AtomicsAnd:
	case AtomicsCompareExchange:
	case AtomicsExchange:
	case AtomicsLoad:
	case AtomicsOr:
	case AtomicsStore:
	case AtomicsSub:
	case AtomicsXor:
	case AtomicsIsLockFree:
	case MatchStructure:
	case FilterCallLinkStatus:
	case FilterGetByIdStatus:
	case FilterPutByIdStatus:
	case FilterInByIdStatus:
	case DateGetInt32OrNaN:
	case DateGetTime:
	case DataViewGetInt:
	case DataViewGetFloat:
	case DataViewSet:
	return false;

	#if !ASSERT_DISABLED
	case ArrayPush:
	case ArrayPop:
	case PushWithScope:
	case CreateActivation:
	case CreateDirectArguments:
	case CreateScopedArguments:
	case CreateClonedArguments:
	case Call:
	case CallEval:
	case CallForwardVarargs:
	case CallObjectConstructor:
	case CallVarargs:
	case CheckTierUpAndOSREnter:
	case CheckTierUpAtReturn:
	case CheckTierUpInLoop:
	case Construct:
	case ConstructForwardVarargs:
	case ConstructVarargs:
	case DefineDataProperty:
	case DefineAccessorProperty:
	case DeleteById:
	case DeleteByVal:
	case DirectCall:
	case DirectConstruct:
	case DirectTailCall:
	case DirectTailCallInlinedCaller:
	case ForceOSRExit:
	case GetById:
	case GetByIdDirect:
	case GetByIdDirectFlush:
	case GetByIdFlush:
	case GetByIdWithThis:
	case GetByValWithThis:
	case GetDirectPname:
	case GetDynamicVar:
	case GetMapBucket:
	case HasGenericProperty:
	case HasIndexedProperty:
	case HasOwnProperty:
	case HasStructureProperty:
	case InById:
	case InByVal:
	case InstanceOf:
	case InstanceOfCustom:
	case LoadVarargs:
	case NumberToStringWithRadix:
	case NumberToStringWithValidRadixConstant:
	case ProfileType:
	case PutById:
	case PutByIdDirect:
	case PutByIdFlush:
	case PutByIdWithThis:
	case PutByOffset:
	case PutByValWithThis:
	case PutDynamicVar:
	case PutGetterById:
	case PutGetterByVal:
	case PutGetterSetterById:
	case PutSetterById:
	case PutSetterByVal:
	case PutStack:
	case PutToArguments:
	case RegExpExec:
	case RegExpExecNonGlobalOrSticky:
	case RegExpMatchFast:
	case RegExpMatchFastGlobal:
	case RegExpTest:
	case ResolveScope:
	case ResolveScopeForHoistingFuncDeclInEval:
	case Return:
	case StringCharAt:
	case TailCall:
	case TailCallForwardVarargs:
	case TailCallForwardVarargsInlinedCaller:
	case TailCallInlinedCaller:
	case TailCallVarargs:
	case TailCallVarargsInlinedCaller:
	case Throw:
	case ToNumber:
	case ToObject:
	case ToPrimitive:
	case ToThis:
	case TryGetById:
	case CreateThis:
	case CreatePromise:
	case CreateGenerator:
	case CreateAsyncGenerator:
	case ObjectCreate:
	case ObjectKeys:
	case AllocatePropertyStorage:
	case ReallocatePropertyStorage:
	case Arrayify:
	case ArrayifyToStructure:
	case NewObject:
	case NewPromise:
	case NewGenerator:
	case NewAsyncGenerator:
	case NewArray:
	case NewArrayWithSpread:
	case Spread:
	case NewArrayWithSize:
	case NewArrayBuffer:
	case NewRegexp:
	case NewStringObject:
	case NewSymbol:
	case MakeRope:
	case NewFunction:
	case NewGeneratorFunction:
	case NewAsyncGeneratorFunction:
	case NewAsyncFunction:
	case NewTypedArray:
	case ThrowStaticError:
	case GetPropertyEnumerator:
	case GetEnumeratorStructurePname:
	case GetEnumeratorGenericPname:
	case ToIndexString:
	case MaterializeNewObject:
	case MaterializeCreateActivation:
	case SetFunctionName:
	case StrCat:
	case StringReplace:
	case StringReplaceRegExp:
	case StringSlice:
	case StringValueOf:
	case CreateRest:
	case ToLowerCase:
	case CallDOMGetter:
	case CallDOM:
	case ArraySlice:
	case ArrayIndexOf:
	case ParseInt: // We might resolve a rope even though we don't clobber anything.
	case SetAdd:
	case MapSet:
	case ValueBitAnd:
	case ValueBitOr:
	case ValueBitXor:
	case ValueBitLShift:
	case ValueBitRShift:
	case ValueAdd:
	case ValueSub:
	case ValueMul:
	case ValueDiv:
	case ValueMod:
	case ValuePow:
	case ValueBitNot:
	case ValueNegate:
	#else
	// See comment at the top for why be default for all nodes should be to
	// return true.
	default:
	#endif
	return true;

	case CallStringConstructor:
	case ToString:
	switch (node->child1().useKind()) {
	case StringObjectUse:
	case StringOrStringObjectUse:
	return false;
	default:
	break;
	}
	return true;

	case CheckTraps:
	// FIXME: https://bugs.webkit.org/show_bug.cgi?id=194323
	ASSERT(Options::usePollingTraps());
	return true;

	case CompareEq:
	case CompareLess:
	case CompareLessEq:
	case CompareGreater:
	case CompareGreaterEq:
	if (node->isBinaryUseKind(Int32Use)
	#if USE(JSVALUE64)
	\|\| node->isBinaryUseKind(Int52RepUse)
	#endif
	\|\| node->isBinaryUseKind(DoubleRepUse)
	\|\| node->isBinaryUseKind(StringIdentUse)
	)
	return false;
	if (node->op() == CompareEq) {
	if (node->isBinaryUseKind(BooleanUse)
	\|\| node->isBinaryUseKind(SymbolUse)
	\|\| node->isBinaryUseKind(ObjectUse)
	\|\| node->isBinaryUseKind(ObjectUse, ObjectOrOtherUse) \|\| node->isBinaryUseKind(ObjectOrOtherUse, ObjectUse))
	return false;
	}
	return true;

	case CompareStrictEq:
	if (node->isBinaryUseKind(BooleanUse)
	\|\| node->isBinaryUseKind(Int32Use)
	#if USE(JSVALUE64)
	\|\| node->isBinaryUseKind(Int52RepUse)
	#endif
	\|\| node->isBinaryUseKind(DoubleRepUse)
	\|\| node->isBinaryUseKind(SymbolUse)
	\|\| node->isBinaryUseKind(SymbolUse, UntypedUse)
	\|\| node->isBinaryUseKind(UntypedUse, SymbolUse)
	\|\| node->isBinaryUseKind(StringIdentUse)
	\|\| node->isBinaryUseKind(ObjectUse, UntypedUse) \|\| node->isBinaryUseKind(UntypedUse, ObjectUse)
	\|\| node->isBinaryUseKind(ObjectUse)
	\|\| node->isBinaryUseKind(MiscUse, UntypedUse) \|\| node->isBinaryUseKind(UntypedUse, MiscUse)
	\|\| node->isBinaryUseKind(StringIdentUse, NotStringVarUse) \|\| node->isBinaryUseKind(NotStringVarUse, StringIdentUse))
	return false;
	return true;

	case GetIndexedPropertyStorage:
	case GetByVal:
	if (node->arrayMode().type() == Array::String)
	return true;
	return false;

	case PutByValDirect:
	case PutByVal:
	case PutByValAlias:
	if (!graph.m_plan.isFTL()) {
	switch (node->arrayMode().modeForPut().type()) {
	case Array::Int8Array:
	case Array::Int16Array:
	case Array::Int32Array:
	case Array::Uint8Array:
	case Array::Uint8ClampedArray:
	case Array::Uint16Array:
	case Array::Uint32Array:
	return true;
	default:
	break;
	}
	}
	return false;

	case MapHash:
	switch (node->child1().useKind()) {
	case BooleanUse:
	case Int32Use:
	case SymbolUse:
	case ObjectUse:
	return false;
	default:
	// We might resolve a rope.
	return true;
	}

	case MultiPutByOffset:
	return node->multiPutByOffsetData().reallocatesStorage();

	case SameValue:
	if (node->isBinaryUseKind(DoubleRepUse))
	return false;
	return true;

	case StringFromCharCode:
	// FIXME: Should we constant fold this case?
	// https://bugs.webkit.org/show_bug.cgi?id=194308
	if (node->child1()->isInt32Constant() && (node->child1()->asUInt32() <= maxSingleCharacterString))
	return false;
	return true;

	case Switch:
	switch (node->switchData()->kind) {
	case SwitchCell:
	ASSERT(graph.m_plan.isFTL());
	FALLTHROUGH;
	case SwitchImm:
	return false;
	case SwitchChar:
	return true;
	case SwitchString:
	if (node->child1().useKind() == StringIdentUse)
	return false;
	ASSERT(node->child1().useKind() == StringUse \|\| node->child1().useKind() == UntypedUse);
	return true;
	}
	RELEASE_ASSERT_NOT_REACHED();

	case LastNodeType:
	RELEASE_ASSERT_NOT_REACHED();
	}

	RELEASE_ASSERT_NOT_REACHED();
	}

	} } // namespace JSC::DFG

	#endif // ENABLE(DFG_JIT)