void LocalOSRAvailabilityCalculator::executeNode(Node* node)
{
    switch (node->op()) {
    case SetLocal: {
        VariableAccessData* variable = node->variableAccessData();
        m_availability.operand(variable->local()) =
            Availability(node->child1().node(), variable->flushedAt());
        break;
    }

    case GetArgument: {
        VariableAccessData* variable = node->variableAccessData();
        m_availability.operand(variable->local()) =
            Availability(node, variable->flushedAt());
        break;
    }

    case MovHint: {
        m_availability.operand(node->unlinkedLocal()) =
            Availability(node->child1().node());
        break;
    }

    case ZombieHint: {
        m_availability.operand(node->unlinkedLocal()) =
            Availability::unavailable();
        break;
    }

    default:
        break;
    }
}
void LocalOSRAvailabilityCalculator::executeNode(Node* node)
{
    switch (node->op()) {
    case PutLocal: {
        VariableAccessData* variable = node->variableAccessData();
        m_availability.m_locals.operand(variable->local()).setFlush(variable->flushedAt());
        break;
    }
        
    case KillLocal: {
        m_availability.m_locals.operand(node->unlinkedLocal()).setFlush(FlushedAt(ConflictingFlush));
        break;
    }

    case GetLocal: {
        VariableAccessData* variable = node->variableAccessData();
        m_availability.m_locals.operand(variable->local()) =
            Availability(node, variable->flushedAt());
        break;
    }

    case MovHint: {
        m_availability.m_locals.operand(node->unlinkedLocal()).setNode(node->child1().node());
        break;
    }

    case ZombieHint: {
        m_availability.m_locals.operand(node->unlinkedLocal()).setNodeUnavailable();
        break;
    }
        
    case LoadVarargs: {
        LoadVarargsData* data = node->loadVarargsData();
        m_availability.m_locals.operand(data->count) =
            Availability(FlushedAt(FlushedInt32, data->machineCount));
        for (unsigned i = data->limit; i--;) {
            m_availability.m_locals.operand(VirtualRegister(data->start.offset() + i)) =
                Availability(FlushedAt(FlushedJSValue, VirtualRegister(data->machineStart.offset() + i)));
        }
        break;
    }
        
    default:
        break;
    }
    
    promoteHeapAccess(
        node,
        [&] (PromotedHeapLocation location, Edge value) {
            m_availability.m_heap.set(location, Availability(value.node()));
        },
        [&] (PromotedHeapLocation) { });
}
void LocalOSRAvailabilityCalculator::executeNode(Node* node)
{
    switch (node->op()) {
    case SetLocal: {
        VariableAccessData* variable = node->variableAccessData();
        m_availability.m_locals.operand(variable->local()) =
            Availability(node->child1().node(), variable->flushedAt());
        break;
    }

    case GetArgument: {
        VariableAccessData* variable = node->variableAccessData();
        m_availability.m_locals.operand(variable->local()) =
            Availability(node, variable->flushedAt());
        break;
    }

    case MovHint: {
        m_availability.m_locals.operand(node->unlinkedLocal()) =
            Availability(node->child1().node());
        break;
    }

    case ZombieHint: {
        m_availability.m_locals.operand(node->unlinkedLocal()) =
            Availability::unavailable();
        break;
    }
        
    default:
        break;
    }
    
    promoteHeapAccess(
        node,
        [&] (PromotedHeapLocation location, Edge value) {
            m_availability.m_heap.set(location, Availability(value.node()));
        },
        [&] (PromotedHeapLocation) { });
}
 bool run()
 {
     ASSERT(m_graph.m_form == SSA);
     
     for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
         BasicBlock* block = m_graph.block(blockIndex);
         if (!block)
             continue;
         block->ssa->availabilityAtHead.fill(Availability());
         block->ssa->availabilityAtTail.fill(Availability());
     }
     
     BasicBlock* root = m_graph.block(0);
     for (unsigned argument = root->ssa->availabilityAtHead.numberOfArguments(); argument--;) {
         root->ssa->availabilityAtHead.argument(argument) =
             Availability::unavailable().withFlush(
                 FlushedAt(FlushedJSValue, virtualRegisterForArgument(argument)));
     }
     for (unsigned local = root->ssa->availabilityAtHead.numberOfLocals(); local--;)
         root->ssa->availabilityAtHead.local(local) = Availability::unavailable();
     
     if (m_graph.m_plan.mode == FTLForOSREntryMode) {
         for (unsigned local = m_graph.m_profiledBlock->m_numCalleeRegisters; local--;) {
             root->ssa->availabilityAtHead.local(local) =
                 Availability::unavailable().withFlush(
                     FlushedAt(FlushedJSValue, virtualRegisterForLocal(local)));
         }
     }
     
     // This could be made more efficient by processing blocks in reverse postorder.
     Operands<Availability> availability;
     bool changed;
     do {
         changed = false;
         
         for (BlockIndex blockIndex = 0; blockIndex < m_graph.numBlocks(); ++blockIndex) {
             BasicBlock* block = m_graph.block(blockIndex);
             if (!block)
                 continue;
             
             availability = block->ssa->availabilityAtHead;
             
             for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
                 Node* node = block->at(nodeIndex);
                 
                 switch (node->op()) {
                 case SetLocal: {
                     VariableAccessData* variable = node->variableAccessData();
                     availability.operand(variable->local()) =
                         Availability(node->child1().node(), variable->flushedAt());
                     break;
                 }
                     
                 case GetArgument: {
                     VariableAccessData* variable = node->variableAccessData();
                     availability.operand(variable->local()) =
                         Availability(node, variable->flushedAt());
                     break;
                 }
                     
                 case MovHint:
                 case MovHintAndCheck: {
                     VariableAccessData* variable = node->variableAccessData();
                     availability.operand(variable->local()) =
                         Availability(node->child1().node());
                     break;
                 }
                     
                 case ZombieHint: {
                     VariableAccessData* variable = node->variableAccessData();
                     availability.operand(variable->local()) = Availability::unavailable();
                     break;
                 }
                     
                 default:
                     break;
                 }
             }
             
             if (availability == block->ssa->availabilityAtTail)
                 continue;
             
             block->ssa->availabilityAtTail = availability;
             changed = true;
             
             for (unsigned successorIndex = block->numSuccessors(); successorIndex--;) {
                 BasicBlock* successor = block->successor(successorIndex);
                 for (unsigned i = availability.size(); i--;) {
                     successor->ssa->availabilityAtHead[i] = availability[i].merge(
                         successor->ssa->availabilityAtHead[i]);
                 }
             }
         }
     } while (changed);
     
     return true;
 }