void treatRootBlock(BasicBlock* block, InsertionSet& insertionSet)
{
Operands<VariableAccessData*> initialAccessData(block->variablesAtTail.numberOfArguments(), block->variablesAtTail.numberOfLocals(), nullptr);
Operands<Node*> initialAccessNodes(block->variablesAtTail.numberOfArguments(), block->variablesAtTail.numberOfLocals(), nullptr);
for (unsigned i = 0; i < block->size(); i++) {
Node* node = block->at(i);
if (!node->hasVariableAccessData(m_graph))
continue;
VirtualRegister operand = node->local();
if (initialAccessData.operand(operand))
continue;
DFG_ASSERT(m_graph, node, node->op() != SetLocal); // We should have inserted a Flush before this!
initialAccessData.operand(operand) = node->variableAccessData();
initialAccessNodes.operand(operand) = node;
}
// We want every Flush to be able to reach backwards to
// a SetLocal. Doing this in the root block achieves this goal.
NodeOrigin origin = block->at(0)->origin;
Node* undefined = insertionSet.insertConstant(0, origin, jsUndefined());
for (unsigned i = 0; i < block->variablesAtTail.numberOfLocals(); i++) {
VirtualRegister operand = virtualRegisterForLocal(i);
VariableAccessData* accessData;
DFG_ASSERT(m_graph, nullptr, initialAccessNodes.operand(operand)->op() == Flush); // We should have inserted a Flush before any SetLocal/SetArgument for the local that we are analyzing now.
accessData = initialAccessData.operand(operand);
DFG_ASSERT(m_graph, nullptr, accessData);
insertionSet.insertNode(0, SpecNone,
SetLocal, origin, OpInfo(accessData), Edge(undefined));
}
}
void treatRegularBlock(BasicBlock* block, InsertionSet& insertionSet)
{
Operands<VariableAccessData*> currentBlockAccessData(block->variablesAtTail.numberOfArguments(), block->variablesAtTail.numberOfLocals(), nullptr);
// Insert a Flush before every SetLocal to properly pattern the graph such that
// any range between SetLocal and Flush has access to the local on the stack.
{
for (unsigned i = 0; i < block->size(); i++) {
Node* node = block->at(i);
bool isPrimordialSetArgument = node->op() == SetArgument && node->local().isArgument() && node == m_graph.m_arguments[node->local().toArgument()];
if (node->op() == SetLocal || (node->op() == SetArgument && !isPrimordialSetArgument)) {
VirtualRegister operand = node->local();
VariableAccessData* flushAccessData = currentBlockAccessData.operand(operand);
if (!flushAccessData)
flushAccessData = newVariableAccessData(operand);
insertionSet.insertNode(i, SpecNone,
Flush, node->origin, OpInfo(flushAccessData));
}
if (node->hasVariableAccessData(m_graph))
currentBlockAccessData.operand(node->local()) = node->variableAccessData();
}
}
// Flush everything at the end of the block.
{
NodeOrigin origin = block->at(block->size() - 1)->origin;
auto insertFlushAtEnd = [&] (VirtualRegister operand) {
VariableAccessData* accessData = currentBlockAccessData.operand(operand);
if (!accessData)
accessData = newVariableAccessData(operand);
currentBlockAccessData.operand(operand) = accessData;
insertionSet.insertNode(block->size(), SpecNone,
Flush, origin, OpInfo(accessData));
};
for (unsigned i = 0; i < block->variablesAtTail.numberOfLocals(); i++)
insertFlushAtEnd(virtualRegisterForLocal(i));
for (unsigned i = 0; i < block->variablesAtTail.numberOfArguments(); i++)
insertFlushAtEnd(virtualRegisterForArgument(i));
}
}
void insertInferredTypeCheck(
InsertionSet& insertionSet, unsigned nodeIndex, NodeOrigin origin, Node* baseNode,
const InferredType::Descriptor& type)
{
insertionSet.graph().registerInferredType(type);
switch (type.kind()) {
case InferredType::Bottom:
insertionSet.insertNode(nodeIndex, SpecNone, ForceOSRExit, origin);
return;
case InferredType::Boolean:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, BooleanUse));
return;
case InferredType::Other:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, OtherUse));
return;
case InferredType::Int32:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, Int32Use));
return;
case InferredType::Number:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, NumberUse));
return;
case InferredType::String:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, StringUse));
return;
case InferredType::Symbol:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, SymbolUse));
return;
case InferredType::ObjectWithStructure:
insertionSet.insertNode(
nodeIndex, SpecNone, CheckStructure, origin,
OpInfo(insertionSet.graph().addStructureSet(type.structure())),
Edge(baseNode, CellUse));
return;
case InferredType::ObjectWithStructureOrOther:
insertionSet.insertNode(
nodeIndex, SpecNone, CheckStructure, origin,
OpInfo(insertionSet.graph().addStructureSet(type.structure())),
Edge(baseNode, CellOrOtherUse));
return;
case InferredType::Object:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, ObjectUse));
return;
case InferredType::ObjectOrOther:
insertionSet.insertNode(nodeIndex, SpecNone, Check, origin, Edge(baseNode, ObjectOrOtherUse));
return;
case InferredType::Top:
return;
}
DFG_CRASH(insertionSet.graph(), baseNode, "Bad inferred type");
}
void handleBlockForTryCatch(BasicBlock* block, InsertionSet& insertionSet)
{
HandlerInfo* currentExceptionHandler = nullptr;
FastBitVector liveAtCatchHead;
liveAtCatchHead.resize(m_graph.block(0)->variablesAtTail.numberOfLocals());
HandlerInfo* cachedHandlerResult;
CodeOrigin cachedCodeOrigin;
auto catchHandler = [&] (CodeOrigin origin) -> HandlerInfo* {
ASSERT(origin);
if (origin == cachedCodeOrigin)
return cachedHandlerResult;
unsigned bytecodeIndexToCheck = origin.bytecodeIndex;
cachedCodeOrigin = origin;
while (1) {
InlineCallFrame* inlineCallFrame = origin.inlineCallFrame;
CodeBlock* codeBlock = m_graph.baselineCodeBlockFor(inlineCallFrame);
if (HandlerInfo* handler = codeBlock->handlerForBytecodeOffset(bytecodeIndexToCheck)) {
liveAtCatchHead.clearAll();
unsigned catchBytecodeIndex = handler->target;
m_graph.forAllLocalsLiveInBytecode(CodeOrigin(catchBytecodeIndex, inlineCallFrame), [&] (VirtualRegister operand) {
liveAtCatchHead[operand.toLocal()] = true;
});
cachedHandlerResult = handler;
break;
}
if (!inlineCallFrame) {
cachedHandlerResult = nullptr;
break;
}
bytecodeIndexToCheck = inlineCallFrame->directCaller.bytecodeIndex;
origin = inlineCallFrame->directCaller;
}
return cachedHandlerResult;
};
Operands<VariableAccessData*> currentBlockAccessData(block->variablesAtTail.numberOfArguments(), block->variablesAtTail.numberOfLocals(), nullptr);
HashSet<InlineCallFrame*> seenInlineCallFrames;
auto flushEverything = [&] (NodeOrigin origin, unsigned index) {
RELEASE_ASSERT(currentExceptionHandler);
auto flush = [&] (VirtualRegister operand, bool alwaysInsert) {
if ((operand.isLocal() && liveAtCatchHead[operand.toLocal()])
|| operand.isArgument()
|| alwaysInsert) {
ASSERT(isValidFlushLocation(block, index, operand));
VariableAccessData* accessData = currentBlockAccessData.operand(operand);
if (!accessData)
accessData = newVariableAccessData(operand);
currentBlockAccessData.operand(operand) = accessData;
insertionSet.insertNode(index, SpecNone,
Flush, origin, OpInfo(accessData));
}
};
for (unsigned local = 0; local < block->variablesAtTail.numberOfLocals(); local++)
flush(virtualRegisterForLocal(local), false);
for (InlineCallFrame* inlineCallFrame : seenInlineCallFrames)
flush(VirtualRegister(inlineCallFrame->stackOffset + CallFrame::thisArgumentOffset()), true);
flush(VirtualRegister(CallFrame::thisArgumentOffset()), true);
seenInlineCallFrames.clear();
};
for (unsigned nodeIndex = 0; nodeIndex < block->size(); nodeIndex++) {
Node* node = block->at(nodeIndex);
{
HandlerInfo* newHandler = catchHandler(node->origin.semantic);
if (newHandler != currentExceptionHandler && currentExceptionHandler)
flushEverything(node->origin, nodeIndex);
currentExceptionHandler = newHandler;
}
if (currentExceptionHandler && (node->op() == SetLocal || node->op() == SetArgument)) {
InlineCallFrame* inlineCallFrame = node->origin.semantic.inlineCallFrame;
if (inlineCallFrame)
seenInlineCallFrames.add(inlineCallFrame);
VirtualRegister operand = node->local();
int stackOffset = inlineCallFrame ? inlineCallFrame->stackOffset : 0;
if ((operand.isLocal() && liveAtCatchHead[operand.toLocal()])
|| operand.isArgument()
|| (operand.offset() == stackOffset + CallFrame::thisArgumentOffset())) {
ASSERT(isValidFlushLocation(block, nodeIndex, operand));
VariableAccessData* variableAccessData = currentBlockAccessData.operand(operand);
if (!variableAccessData)
variableAccessData = newVariableAccessData(operand);
insertionSet.insertNode(nodeIndex, SpecNone,
Flush, node->origin, OpInfo(variableAccessData));
}
}
if (node->accessesStack(m_graph))
currentBlockAccessData.operand(node->local()) = node->variableAccessData();
}
if (currentExceptionHandler) {
NodeOrigin origin = block->at(block->size() - 1)->origin;
flushEverything(origin, block->size());
}
}