void AbstractValue::checkConsistency() const
{
if (!(m_type & SpecCell)) {
ASSERT(m_currentKnownStructure.isClear());
ASSERT(m_futurePossibleStructure.isClear());
ASSERT(!m_arrayModes);
}
if (isClear())
ASSERT(!m_value);
if (!!m_value)
ASSERT(mergeSpeculations(m_type, speculationFromValue(m_value)) == m_type);
// Note that it's possible for a prediction like (Final, []). This really means that
// the value is bottom and that any code that uses the value is unreachable. But
// we don't want to get pedantic about this as it would only increase the computational
// complexity of the code.
}
void AbstractValue::checkConsistency() const
{
if (!(m_type & SpecCell)) {
ASSERT(m_structure.isClear());
ASSERT(!m_arrayModes);
}
if (isClear())
ASSERT(!m_value);
if (!!m_value) {
SpeculatedType type = m_type;
// This relaxes the assertion below a bit, since we don't know the representation of the
// node.
if (type & SpecInt52)
type |= SpecInt52AsDouble;
ASSERT(mergeSpeculations(type, speculationFromValue(m_value)) == type);
}
// Note that it's possible for a prediction like (Final, []). This really means that
// the value is bottom and that any code that uses the value is unreachable. But
// we don't want to get pedantic about this as it would only increase the computational
// complexity of the code.
}
void propagate(Node& node)
{
if (!node.shouldGenerate())
return;
NodeType op = node.op();
NodeFlags flags = node.flags() & NodeBackPropMask;
#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
dataLog(" %s @%u: %s ", Graph::opName(op), m_compileIndex, nodeFlagsAsString(flags));
#endif
bool changed = false;
switch (op) {
case JSConstant:
case WeakJSConstant: {
changed |= setPrediction(speculationFromValue(m_graph.valueOfJSConstant(m_compileIndex)));
break;
}
case GetLocal: {
VariableAccessData* variableAccessData = node.variableAccessData();
SpeculatedType prediction = variableAccessData->prediction();
if (prediction)
changed |= mergePrediction(prediction);
changed |= variableAccessData->mergeFlags(flags);
break;
}
case SetLocal: {
VariableAccessData* variableAccessData = node.variableAccessData();
changed |= variableAccessData->predict(m_graph[node.child1()].prediction());
changed |= m_graph[node.child1()].mergeFlags(variableAccessData->flags());
break;
}
case Flush: {
// Make sure that the analysis knows that flushed locals escape.
VariableAccessData* variableAccessData = node.variableAccessData();
changed |= variableAccessData->mergeFlags(NodeUsedAsValue);
break;
}
case BitAnd:
case BitOr:
case BitXor:
case BitRShift:
case BitLShift:
case BitURShift: {
changed |= setPrediction(SpecInt32);
flags |= NodeUsedAsInt;
flags &= ~(NodeUsedAsNumber | NodeNeedsNegZero);
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ValueToInt32: {
changed |= setPrediction(SpecInt32);
flags |= NodeUsedAsInt;
flags &= ~(NodeUsedAsNumber | NodeNeedsNegZero);
changed |= m_graph[node.child1()].mergeFlags(flags);
break;
}
case ArrayPop: {
changed |= mergePrediction(node.getHeapPrediction());
changed |= mergeDefaultFlags(node);
break;
}
case ArrayPush: {
changed |= mergePrediction(node.getHeapPrediction());
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
changed |= m_graph[node.child2()].mergeFlags(NodeUsedAsValue);
break;
}
case RegExpExec:
case RegExpTest: {
changed |= mergePrediction(node.getHeapPrediction());
changed |= mergeDefaultFlags(node);
break;
}
case StringCharCodeAt: {
changed |= mergePrediction(SpecInt32);
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
changed |= m_graph[node.child2()].mergeFlags(NodeUsedAsNumber | NodeUsedAsInt);
break;
}
case ArithMod: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (isInt32Speculation(mergeSpeculations(left, right))
&& nodeCanSpeculateInteger(node.arithNodeFlags()))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(SpecDouble);
}
flags |= NodeUsedAsValue;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case UInt32ToNumber: {
if (nodeCanSpeculateInteger(node.arithNodeFlags()))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(SpecNumber);
changed |= m_graph[node.child1()].mergeFlags(flags);
break;
}
case ValueAdd: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (isNumberSpeculation(left) && isNumberSpeculation(right)) {
if (m_graph.addShouldSpeculateInteger(node))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(speculatedDoubleTypeForPredictions(left, right));
} else if (!(left & SpecNumber) || !(right & SpecNumber)) {
// left or right is definitely something other than a number.
changed |= mergePrediction(SpecString);
} else
changed |= mergePrediction(SpecString | SpecInt32 | SpecDouble);
}
if (isNotNegZero(node.child1().index()) || isNotNegZero(node.child2().index()))
flags &= ~NodeNeedsNegZero;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ArithAdd: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (m_graph.addShouldSpeculateInteger(node))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(speculatedDoubleTypeForPredictions(left, right));
}
if (isNotNegZero(node.child1().index()) || isNotNegZero(node.child2().index()))
flags &= ~NodeNeedsNegZero;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ArithSub: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (m_graph.addShouldSpeculateInteger(node))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(speculatedDoubleTypeForPredictions(left, right));
}
if (isNotZero(node.child1().index()) || isNotZero(node.child2().index()))
flags &= ~NodeNeedsNegZero;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ArithNegate:
if (m_graph[node.child1()].prediction()) {
if (m_graph.negateShouldSpeculateInteger(node))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(speculatedDoubleTypeForPrediction(m_graph[node.child1()].prediction()));
}
changed |= m_graph[node.child1()].mergeFlags(flags);
break;
case ArithMin:
case ArithMax: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (isInt32Speculation(mergeSpeculations(left, right))
&& nodeCanSpeculateInteger(node.arithNodeFlags()))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(speculatedDoubleTypeForPredictions(left, right));
}
flags |= NodeUsedAsNumber;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ArithMul: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (m_graph.mulShouldSpeculateInteger(node))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(speculatedDoubleTypeForPredictions(left, right));
}
// As soon as a multiply happens, we can easily end up in the part
// of the double domain where the point at which you do truncation
// can change the outcome. So, ArithMul always checks for overflow
// no matter what, and always forces its inputs to check as well.
flags |= NodeUsedAsNumber | NodeNeedsNegZero;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ArithDiv: {
SpeculatedType left = m_graph[node.child1()].prediction();
SpeculatedType right = m_graph[node.child2()].prediction();
if (left && right) {
if (isInt32Speculation(mergeSpeculations(left, right))
&& nodeCanSpeculateInteger(node.arithNodeFlags()))
changed |= mergePrediction(SpecInt32);
else
changed |= mergePrediction(SpecDouble);
}
// As soon as a multiply happens, we can easily end up in the part
// of the double domain where the point at which you do truncation
// can change the outcome. So, ArithMul always checks for overflow
// no matter what, and always forces its inputs to check as well.
flags |= NodeUsedAsNumber | NodeNeedsNegZero;
changed |= m_graph[node.child1()].mergeFlags(flags);
changed |= m_graph[node.child2()].mergeFlags(flags);
break;
}
case ArithSqrt: {
changed |= setPrediction(SpecDouble);
changed |= m_graph[node.child1()].mergeFlags(flags | NodeUsedAsValue);
break;
}
case ArithAbs: {
SpeculatedType child = m_graph[node.child1()].prediction();
if (nodeCanSpeculateInteger(node.arithNodeFlags()))
changed |= mergePrediction(child);
else
changed |= setPrediction(speculatedDoubleTypeForPrediction(child));
flags &= ~NodeNeedsNegZero;
changed |= m_graph[node.child1()].mergeFlags(flags);
break;
}
case LogicalNot:
case CompareLess:
case CompareLessEq:
case CompareGreater:
case CompareGreaterEq:
case CompareEq:
case CompareStrictEq:
case InstanceOf:
case IsUndefined:
case IsBoolean:
case IsNumber:
case IsString:
case IsObject:
case IsFunction: {
changed |= setPrediction(SpecBoolean);
changed |= mergeDefaultFlags(node);
break;
}
case GetById: {
changed |= mergePrediction(node.getHeapPrediction());
changed |= mergeDefaultFlags(node);
break;
}
case GetByIdFlush:
changed |= mergePrediction(node.getHeapPrediction());
changed |= mergeDefaultFlags(node);
break;
case GetByVal: {
if (m_graph[node.child1()].shouldSpeculateFloat32Array()
|| m_graph[node.child1()].shouldSpeculateFloat64Array())
changed |= mergePrediction(SpecDouble);
else
changed |= mergePrediction(node.getHeapPrediction());
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
changed |= m_graph[node.child2()].mergeFlags(NodeUsedAsNumber | NodeUsedAsInt);
break;
}
case GetMyArgumentByValSafe: {
changed |= mergePrediction(node.getHeapPrediction());
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsNumber | NodeUsedAsInt);
break;
}
case GetMyArgumentsLengthSafe: {
changed |= setPrediction(SpecInt32);
break;
}
case GetScopeRegisters:
case GetButterfly:
case GetIndexedPropertyStorage:
case AllocatePropertyStorage:
case ReallocatePropertyStorage: {
changed |= setPrediction(SpecOther);
changed |= mergeDefaultFlags(node);
break;
}
case GetByOffset: {
changed |= mergePrediction(node.getHeapPrediction());
changed |= mergeDefaultFlags(node);
break;
}
case Call:
case Construct: {
changed |= mergePrediction(node.getHeapPrediction());
for (unsigned childIdx = node.firstChild();
childIdx < node.firstChild() + node.numChildren();
++childIdx) {
Edge edge = m_graph.m_varArgChildren[childIdx];
changed |= m_graph[edge].mergeFlags(NodeUsedAsValue);
}
break;
}
case ConvertThis: {
SpeculatedType prediction = m_graph[node.child1()].prediction();
if (prediction) {
if (prediction & ~SpecObjectMask) {
prediction &= SpecObjectMask;
prediction = mergeSpeculations(prediction, SpecObjectOther);
}
changed |= mergePrediction(prediction);
}
changed |= mergeDefaultFlags(node);
break;
}
case GetGlobalVar: {
changed |= mergePrediction(node.getHeapPrediction());
break;
}
case PutGlobalVar:
case PutGlobalVarCheck: {
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
break;
}
case GetScopedVar:
case Resolve:
case ResolveBase:
case ResolveBaseStrictPut:
case ResolveGlobal: {
SpeculatedType prediction = node.getHeapPrediction();
changed |= mergePrediction(prediction);
break;
}
case GetScope: {
changed |= setPrediction(SpecCellOther);
break;
}
case GetCallee: {
changed |= setPrediction(SpecFunction);
break;
}
case CreateThis:
case NewObject: {
changed |= setPrediction(SpecFinalObject);
changed |= mergeDefaultFlags(node);
break;
}
case NewArray: {
changed |= setPrediction(SpecArray);
for (unsigned childIdx = node.firstChild();
childIdx < node.firstChild() + node.numChildren();
++childIdx) {
Edge edge = m_graph.m_varArgChildren[childIdx];
changed |= m_graph[edge].mergeFlags(NodeUsedAsValue);
}
break;
}
case NewArrayWithSize: {
changed |= setPrediction(SpecArray);
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsNumber | NodeUsedAsInt);
break;
}
case NewArrayBuffer: {
changed |= setPrediction(SpecArray);
break;
}
case NewRegexp: {
changed |= setPrediction(SpecObjectOther);
break;
}
case StringCharAt: {
changed |= setPrediction(SpecString);
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
changed |= m_graph[node.child2()].mergeFlags(NodeUsedAsNumber | NodeUsedAsInt);
break;
}
case StrCat: {
changed |= setPrediction(SpecString);
for (unsigned childIdx = node.firstChild();
childIdx < node.firstChild() + node.numChildren();
++childIdx)
changed |= m_graph[m_graph.m_varArgChildren[childIdx]].mergeFlags(NodeUsedAsNumber);
break;
}
case ToPrimitive: {
SpeculatedType child = m_graph[node.child1()].prediction();
if (child) {
if (isObjectSpeculation(child)) {
// I'd love to fold this case into the case below, but I can't, because
// removing SpecObjectMask from something that only has an object
// prediction and nothing else means we have an ill-formed SpeculatedType
// (strong predict-none). This should be killed once we remove all traces
// of static (aka weak) predictions.
changed |= mergePrediction(SpecString);
} else if (child & SpecObjectMask) {
// Objects get turned into strings. So if the input has hints of objectness,
// the output will have hinsts of stringiness.
changed |= mergePrediction(
mergeSpeculations(child & ~SpecObjectMask, SpecString));
} else
changed |= mergePrediction(child);
}
changed |= m_graph[node.child1()].mergeFlags(flags);
break;
}
case CreateActivation: {
changed |= setPrediction(SpecObjectOther);
break;
}
case CreateArguments: {
// At this stage we don't try to predict whether the arguments are ours or
// someone else's. We could, but we don't, yet.
changed |= setPrediction(SpecArguments);
break;
}
case NewFunction:
case NewFunctionNoCheck:
case NewFunctionExpression: {
changed |= setPrediction(SpecFunction);
break;
}
case PutByValAlias:
case GetArrayLength:
case Int32ToDouble:
case DoubleAsInt32:
case GetLocalUnlinked:
case GetMyArgumentsLength:
case GetMyArgumentByVal:
case PhantomPutStructure:
case PhantomArguments:
case CheckArray:
case Arrayify: {
// This node should never be visible at this stage of compilation. It is
// inserted by fixup(), which follows this phase.
ASSERT_NOT_REACHED();
break;
}
case PutByVal:
changed |= m_graph[m_graph.varArgChild(node, 0)].mergeFlags(NodeUsedAsValue);
changed |= m_graph[m_graph.varArgChild(node, 1)].mergeFlags(NodeUsedAsNumber | NodeUsedAsInt);
changed |= m_graph[m_graph.varArgChild(node, 2)].mergeFlags(NodeUsedAsValue);
break;
case PutScopedVar:
case Return:
case Throw:
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
break;
case PutById:
case PutByIdDirect:
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
changed |= m_graph[node.child2()].mergeFlags(NodeUsedAsValue);
break;
case PutByOffset:
changed |= m_graph[node.child1()].mergeFlags(NodeUsedAsValue);
changed |= m_graph[node.child3()].mergeFlags(NodeUsedAsValue);
break;
case Phi:
break;
#ifndef NDEBUG
// These get ignored because they don't return anything.
case DFG::Jump:
case Branch:
case Breakpoint:
case CheckHasInstance:
case ThrowReferenceError:
case ForceOSRExit:
case SetArgument:
case CheckStructure:
case ForwardCheckStructure:
case StructureTransitionWatchpoint:
case ForwardStructureTransitionWatchpoint:
case CheckFunction:
case PutStructure:
case TearOffActivation:
case TearOffArguments:
case CheckNumber:
case CheckArgumentsNotCreated:
case GlobalVarWatchpoint:
case GarbageValue:
changed |= mergeDefaultFlags(node);
break;
// These gets ignored because it doesn't do anything.
case Phantom:
case InlineStart:
case Nop:
break;
case LastNodeType:
ASSERT_NOT_REACHED();
break;
#else
default:
changed |= mergeDefaultFlags(node);
break;
#endif
}
#if DFG_ENABLE(DEBUG_PROPAGATION_VERBOSE)
dataLog("%s\n", speculationToString(m_graph[m_compileIndex].prediction()));
#endif
m_changed |= changed;
}
SpeculatedType speculatedDoubleTypeForPredictions(SpeculatedType left, SpeculatedType right)
{
return speculatedDoubleTypeForPrediction(mergeSpeculations(left, right));
}
