void JITCompiler::noticeOSREntry(BasicBlock& basicBlock, JITCompiler::Label blockHead, LinkBuffer& linkBuffer) { // OSR entry is not allowed into blocks deemed unreachable by control flow analysis. if (!basicBlock.intersectionOfCFAHasVisited) return; OSREntryData* entry = m_jitCode->appendOSREntryData(basicBlock.bytecodeBegin, linkBuffer.offsetOf(blockHead)); entry->m_expectedValues = basicBlock.intersectionOfPastValuesAtHead; // Fix the expected values: in our protocol, a dead variable will have an expected // value of (None, []). But the old JIT may stash some values there. So we really // need (Top, TOP). for (size_t argument = 0; argument < basicBlock.variablesAtHead.numberOfArguments(); ++argument) { Node* node = basicBlock.variablesAtHead.argument(argument); if (!node || !node->shouldGenerate()) entry->m_expectedValues.argument(argument).makeHeapTop(); } for (size_t local = 0; local < basicBlock.variablesAtHead.numberOfLocals(); ++local) { Node* node = basicBlock.variablesAtHead.local(local); if (!node || !node->shouldGenerate()) entry->m_expectedValues.local(local).makeHeapTop(); else { VariableAccessData* variable = node->variableAccessData(); entry->m_machineStackUsed.set(variable->machineLocal().toLocal()); switch (variable->flushFormat()) { case FlushedDouble: entry->m_localsForcedDouble.set(local); break; case FlushedInt52: entry->m_localsForcedMachineInt.set(local); break; default: break; } if (variable->local() != variable->machineLocal()) { entry->m_reshufflings.append( OSREntryReshuffling( variable->local().offset(), variable->machineLocal().offset())); } } } entry->m_reshufflings.shrinkToFit(); }
bool run() { // This enumerates the locals that we actually care about and packs them. So for example // if we use local 1, 3, 4, 5, 7, then we remap them: 1->0, 3->1, 4->2, 5->3, 7->4. We // treat a variable as being "used" if there exists an access to it (SetLocal, GetLocal, // Flush, PhantomLocal). BitVector usedLocals; // Collect those variables that are used from IR. bool hasNodesThatNeedFixup = false; for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) { BasicBlock* block = m_graph.block(blockIndex); if (!block) continue; for (unsigned nodeIndex = block->size(); nodeIndex--;) { Node* node = block->at(nodeIndex); switch (node->op()) { case GetLocal: case SetLocal: case Flush: case PhantomLocal: { VariableAccessData* variable = node->variableAccessData(); if (variable->local().isArgument()) break; usedLocals.set(variable->local().toLocal()); break; } case GetLocalUnlinked: { VirtualRegister operand = node->unlinkedLocal(); if (operand.isArgument()) break; usedLocals.set(operand.toLocal()); hasNodesThatNeedFixup = true; break; } case LoadVarargs: case ForwardVarargs: { LoadVarargsData* data = node->loadVarargsData(); if (data->count.isLocal()) usedLocals.set(data->count.toLocal()); if (data->start.isLocal()) { // This part really relies on the contiguity of stack layout // assignments. ASSERT(VirtualRegister(data->start.offset() + data->limit - 1).isLocal()); for (unsigned i = data->limit; i--;) usedLocals.set(VirtualRegister(data->start.offset() + i).toLocal()); } // the else case shouldn't happen. hasNodesThatNeedFixup = true; break; } case PutStack: case GetStack: { StackAccessData* stack = node->stackAccessData(); if (stack->local.isArgument()) break; usedLocals.set(stack->local.toLocal()); break; } default: break; } } } for (InlineCallFrameSet::iterator iter = m_graph.m_plan.inlineCallFrames->begin(); !!iter; ++iter) { InlineCallFrame* inlineCallFrame = *iter; if (inlineCallFrame->isVarargs()) { usedLocals.set(VirtualRegister( JSStack::ArgumentCount + inlineCallFrame->stackOffset).toLocal()); } for (unsigned argument = inlineCallFrame->arguments.size(); argument-- > 1;) { usedLocals.set(VirtualRegister( virtualRegisterForArgument(argument).offset() + inlineCallFrame->stackOffset).toLocal()); } } Vector<unsigned> allocation(usedLocals.size()); m_graph.m_nextMachineLocal = 0; for (unsigned i = 0; i < usedLocals.size(); ++i) { if (!usedLocals.get(i)) { allocation[i] = UINT_MAX; continue; } allocation[i] = m_graph.m_nextMachineLocal++; } for (unsigned i = m_graph.m_variableAccessData.size(); i--;) { VariableAccessData* variable = &m_graph.m_variableAccessData[i]; if (!variable->isRoot()) continue; if (variable->local().isArgument()) { variable->machineLocal() = variable->local(); continue; } size_t local = variable->local().toLocal(); if (local >= allocation.size()) continue; if (allocation[local] == UINT_MAX) continue; variable->machineLocal() = assign(allocation, variable->local()); } for (StackAccessData* data : m_graph.m_stackAccessData) { if (!data->local.isLocal()) { data->machineLocal = data->local; continue; } if (static_cast<size_t>(data->local.toLocal()) >= allocation.size()) continue; if (allocation[data->local.toLocal()] == UINT_MAX) continue; data->machineLocal = assign(allocation, data->local); } // This register is never valid for DFG code blocks. codeBlock()->setActivationRegister(VirtualRegister()); if (LIKELY(!m_graph.hasDebuggerEnabled())) codeBlock()->setScopeRegister(VirtualRegister()); else codeBlock()->setScopeRegister(assign(allocation, codeBlock()->scopeRegister())); for (unsigned i = m_graph.m_inlineVariableData.size(); i--;) { InlineVariableData data = m_graph.m_inlineVariableData[i]; InlineCallFrame* inlineCallFrame = data.inlineCallFrame; if (inlineCallFrame->isVarargs()) { inlineCallFrame->argumentCountRegister = assign( allocation, VirtualRegister(inlineCallFrame->stackOffset + JSStack::ArgumentCount)); } for (unsigned argument = inlineCallFrame->arguments.size(); argument-- > 1;) { ArgumentPosition& position = m_graph.m_argumentPositions[ data.argumentPositionStart + argument]; VariableAccessData* variable = position.someVariable(); ValueSource source; if (!variable) source = ValueSource(SourceIsDead); else { source = ValueSource::forFlushFormat( variable->machineLocal(), variable->flushFormat()); } inlineCallFrame->arguments[argument] = source.valueRecovery(); } RELEASE_ASSERT(inlineCallFrame->isClosureCall == !!data.calleeVariable); if (inlineCallFrame->isClosureCall) { VariableAccessData* variable = data.calleeVariable->find(); ValueSource source = ValueSource::forFlushFormat( variable->machineLocal(), variable->flushFormat()); inlineCallFrame->calleeRecovery = source.valueRecovery(); } else RELEASE_ASSERT(inlineCallFrame->calleeRecovery.isConstant()); } // Fix GetLocalUnlinked's variable references. if (hasNodesThatNeedFixup) { for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) { BasicBlock* block = m_graph.block(blockIndex); if (!block) continue; for (unsigned nodeIndex = block->size(); nodeIndex--;) { Node* node = block->at(nodeIndex); switch (node->op()) { case GetLocalUnlinked: { node->setUnlinkedMachineLocal(assign(allocation, node->unlinkedLocal())); break; } case LoadVarargs: case ForwardVarargs: { LoadVarargsData* data = node->loadVarargsData(); data->machineCount = assign(allocation, data->count); data->machineStart = assign(allocation, data->start); break; } default: break; } } } } return true; }
bool run() { SharedSymbolTable* symbolTable = codeBlock()->symbolTable(); // This enumerates the locals that we actually care about and packs them. So for example // if we use local 1, 3, 4, 5, 7, then we remap them: 1->0, 3->1, 4->2, 5->3, 7->4. We // treat a variable as being "used" if there exists an access to it (SetLocal, GetLocal, // Flush, PhantomLocal). BitVector usedLocals; // Collect those variables that are used from IR. bool hasGetLocalUnlinked = false; for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) { BasicBlock* block = m_graph.block(blockIndex); if (!block) continue; for (unsigned nodeIndex = block->size(); nodeIndex--;) { Node* node = block->at(nodeIndex); switch (node->op()) { case GetLocal: case SetLocal: case Flush: case PhantomLocal: { VariableAccessData* variable = node->variableAccessData(); if (variable->local().isArgument()) break; usedLocals.set(variable->local().toLocal()); break; } case GetLocalUnlinked: { VirtualRegister operand = node->unlinkedLocal(); if (operand.isArgument()) break; usedLocals.set(operand.toLocal()); hasGetLocalUnlinked = true; break; } default: break; } } } // Ensure that captured variables and captured inline arguments are pinned down. // They should have been because of flushes, except that the flushes can be optimized // away. if (symbolTable) { for (int i = symbolTable->captureStart(); i > symbolTable->captureEnd(); i--) usedLocals.set(VirtualRegister(i).toLocal()); } if (codeBlock()->usesArguments()) { usedLocals.set(codeBlock()->argumentsRegister().toLocal()); usedLocals.set(unmodifiedArgumentsRegister(codeBlock()->argumentsRegister()).toLocal()); } if (codeBlock()->uncheckedActivationRegister().isValid()) usedLocals.set(codeBlock()->activationRegister().toLocal()); for (InlineCallFrameSet::iterator iter = m_graph.m_inlineCallFrames->begin(); !!iter; ++iter) { InlineCallFrame* inlineCallFrame = *iter; if (!inlineCallFrame->executable->usesArguments()) continue; VirtualRegister argumentsRegister = m_graph.argumentsRegisterFor(inlineCallFrame); usedLocals.set(argumentsRegister.toLocal()); usedLocals.set(unmodifiedArgumentsRegister(argumentsRegister).toLocal()); for (unsigned argument = inlineCallFrame->arguments.size(); argument-- > 1;) { usedLocals.set(VirtualRegister( virtualRegisterForArgument(argument).offset() + inlineCallFrame->stackOffset).toLocal()); } } Vector<unsigned> allocation(usedLocals.size()); m_graph.m_nextMachineLocal = 0; for (unsigned i = 0; i < usedLocals.size(); ++i) { if (!usedLocals.get(i)) { allocation[i] = UINT_MAX; continue; } allocation[i] = m_graph.m_nextMachineLocal++; } for (unsigned i = m_graph.m_variableAccessData.size(); i--;) { VariableAccessData* variable = &m_graph.m_variableAccessData[i]; if (!variable->isRoot()) continue; if (variable->local().isArgument()) { variable->machineLocal() = variable->local(); continue; } size_t local = variable->local().toLocal(); if (local >= allocation.size()) continue; if (allocation[local] == UINT_MAX) continue; variable->machineLocal() = virtualRegisterForLocal( allocation[variable->local().toLocal()]); } if (codeBlock()->usesArguments()) { VirtualRegister argumentsRegister = virtualRegisterForLocal( allocation[codeBlock()->argumentsRegister().toLocal()]); RELEASE_ASSERT( virtualRegisterForLocal(allocation[ unmodifiedArgumentsRegister( codeBlock()->argumentsRegister()).toLocal()]) == unmodifiedArgumentsRegister(argumentsRegister)); codeBlock()->setArgumentsRegister(argumentsRegister); } if (codeBlock()->uncheckedActivationRegister().isValid()) { codeBlock()->setActivationRegister( virtualRegisterForLocal(allocation[codeBlock()->activationRegister().toLocal()])); } for (unsigned i = m_graph.m_inlineVariableData.size(); i--;) { InlineVariableData data = m_graph.m_inlineVariableData[i]; InlineCallFrame* inlineCallFrame = data.inlineCallFrame; if (inlineCallFrame->executable->usesArguments()) { inlineCallFrame->argumentsRegister = virtualRegisterForLocal( allocation[m_graph.argumentsRegisterFor(inlineCallFrame).toLocal()]); RELEASE_ASSERT( virtualRegisterForLocal(allocation[unmodifiedArgumentsRegister( m_graph.argumentsRegisterFor(inlineCallFrame)).toLocal()]) == unmodifiedArgumentsRegister(inlineCallFrame->argumentsRegister)); } for (unsigned argument = inlineCallFrame->arguments.size(); argument-- > 1;) { ArgumentPosition& position = m_graph.m_argumentPositions[ data.argumentPositionStart + argument]; VariableAccessData* variable = position.someVariable(); ValueSource source; if (!variable) source = ValueSource(SourceIsDead); else { source = ValueSource::forFlushFormat( variable->machineLocal(), variable->flushFormat()); } inlineCallFrame->arguments[argument] = source.valueRecovery(); } RELEASE_ASSERT(inlineCallFrame->isClosureCall == !!data.calleeVariable); if (inlineCallFrame->isClosureCall) { ValueSource source = ValueSource::forFlushFormat( data.calleeVariable->machineLocal(), data.calleeVariable->flushFormat()); inlineCallFrame->calleeRecovery = source.valueRecovery(); } else RELEASE_ASSERT(inlineCallFrame->calleeRecovery.isConstant()); } if (symbolTable) { if (symbolTable->captureCount()) { unsigned captureStartLocal = allocation[ VirtualRegister(codeBlock()->symbolTable()->captureStart()).toLocal()]; ASSERT(captureStartLocal != UINT_MAX); m_graph.m_machineCaptureStart = virtualRegisterForLocal(captureStartLocal).offset(); } else m_graph.m_machineCaptureStart = virtualRegisterForLocal(0).offset(); // This is an abomination. If we had captured an argument then the argument ends // up being "slow", meaning that loads of the argument go through an extra lookup // table. if (const SlowArgument* slowArguments = symbolTable->slowArguments()) { auto newSlowArguments = std::make_unique<SlowArgument[]>( symbolTable->parameterCount()); for (size_t i = symbolTable->parameterCount(); i--;) { newSlowArguments[i] = slowArguments[i]; VirtualRegister reg = VirtualRegister(slowArguments[i].index); if (reg.isLocal()) newSlowArguments[i].index = virtualRegisterForLocal(allocation[reg.toLocal()]).offset(); } m_graph.m_slowArguments = std::move(newSlowArguments); } } // Fix GetLocalUnlinked's variable references. if (hasGetLocalUnlinked) { for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) { BasicBlock* block = m_graph.block(blockIndex); if (!block) continue; for (unsigned nodeIndex = block->size(); nodeIndex--;) { Node* node = block->at(nodeIndex); switch (node->op()) { case GetLocalUnlinked: { VirtualRegister operand = node->unlinkedLocal(); if (operand.isLocal()) operand = virtualRegisterForLocal(allocation[operand.toLocal()]); node->setUnlinkedMachineLocal(operand); break; } default: break; } } } } return true; }