C++ SafePointNode类代码示例

void LateInlineCallGenerator::do_late_inline() {
  // Can't inline it
  CallStaticJavaNode* call = call_node();
  if (call == NULL || call->outcnt() == 0 ||
      call->in(0) == NULL || call->in(0)->is_top()) {
    return;
  }

  const TypeTuple *r = call->tf()->domain();
  for (int i1 = 0; i1 < method()->arg_size(); i1++) {
    if (call->in(TypeFunc::Parms + i1)->is_top() && r->field_at(TypeFunc::Parms + i1) != Type::HALF) {
      assert(Compile::current()->inlining_incrementally(), "shouldn't happen during parsing");
      return;
    }
  }

  if (call->in(TypeFunc::Memory)->is_top()) {
    assert(Compile::current()->inlining_incrementally(), "shouldn't happen during parsing");
    return;
  }

  Compile* C = Compile::current();
  // Remove inlined methods from Compiler's lists.
  if (call->is_macro()) {
    C->remove_macro_node(call);
  }

  // Make a clone of the JVMState that appropriate to use for driving a parse
  JVMState* old_jvms = call->jvms();
  JVMState* jvms = old_jvms->clone_shallow(C);
  uint size = call->req();
  SafePointNode* map = new (C) SafePointNode(size, jvms);
  for (uint i1 = 0; i1 < size; i1++) {
    map->init_req(i1, call->in(i1));
  }

  // Make sure the state is a MergeMem for parsing.
  if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
    Node* mem = MergeMemNode::make(C, map->in(TypeFunc::Memory));
    C->initial_gvn()->set_type_bottom(mem);
    map->set_req(TypeFunc::Memory, mem);
  }

  uint nargs = method()->arg_size();
  // blow away old call arguments
  Node* top = C->top();
  for (uint i1 = 0; i1 < nargs; i1++) {
    map->set_req(TypeFunc::Parms + i1, top);
  }
  jvms->set_map(map);

  // Make enough space in the expression stack to transfer
  // the incoming arguments and return value.
  map->ensure_stack(jvms, jvms->method()->max_stack());
  for (uint i1 = 0; i1 < nargs; i1++) {
    map->set_argument(jvms, i1, call->in(TypeFunc::Parms + i1));
  }

  // This check is done here because for_method_handle_inline() method
  // needs jvms for inlined state.
  if (!do_late_inline_check(jvms)) {
    map->disconnect_inputs(NULL, C);
    return;
  }

  C->print_inlining_insert(this);

  CompileLog* log = C->log();
  if (log != NULL) {
    log->head("late_inline method='%d'", log->identify(method()));
    JVMState* p = jvms;
    while (p != NULL) {
      log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
      p = p->caller();
    }
    log->tail("late_inline");
  }

  // Setup default node notes to be picked up by the inlining
  Node_Notes* old_nn = C->default_node_notes();
  if (old_nn != NULL) {
    Node_Notes* entry_nn = old_nn->clone(C);
    entry_nn->set_jvms(jvms);
    C->set_default_node_notes(entry_nn);
  }

  // Now perform the inling using the synthesized JVMState
  JVMState* new_jvms = _inline_cg->generate(jvms, NULL);
  if (new_jvms == NULL)  return;  // no change
  if (C->failing())      return;

  // Capture any exceptional control flow
  GraphKit kit(new_jvms);

  // Find the result object
  Node* result = C->top();
  int   result_size = method()->return_type()->size();
  if (result_size != 0 && !kit.stopped()) {
    result = (result_size == 1) ? kit.pop() : kit.pop_pair();
  }
//.........这里部分代码省略.........

void LateInlineCallGenerator::do_late_inline() {
  // Can't inline it
  if (call_node() == NULL || call_node()->outcnt() == 0 ||
      call_node()->in(0) == NULL || call_node()->in(0)->is_top())
    return;

  CallStaticJavaNode* call = call_node();

  // Make a clone of the JVMState that appropriate to use for driving a parse
  Compile* C = Compile::current();
  JVMState* jvms     = call->jvms()->clone_shallow(C);
  uint size = call->req();
  SafePointNode* map = new (C, size) SafePointNode(size, jvms);
  for (uint i1 = 0; i1 < size; i1++) {
    map->init_req(i1, call->in(i1));
  }

  // Make sure the state is a MergeMem for parsing.
  if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
    map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
  }

  // Make enough space for the expression stack and transfer the incoming arguments
  int nargs    = method()->arg_size();
  jvms->set_map(map);
  map->ensure_stack(jvms, jvms->method()->max_stack());
  if (nargs > 0) {
    for (int i1 = 0; i1 < nargs; i1++) {
      map->set_req(i1 + jvms->argoff(), call->in(TypeFunc::Parms + i1));
    }
  }

  CompileLog* log = C->log();
  if (log != NULL) {
    log->head("late_inline method='%d'", log->identify(method()));
    JVMState* p = jvms;
    while (p != NULL) {
      log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
      p = p->caller();
    }
    log->tail("late_inline");
  }

  // Setup default node notes to be picked up by the inlining
  Node_Notes* old_nn = C->default_node_notes();
  if (old_nn != NULL) {
    Node_Notes* entry_nn = old_nn->clone(C);
    entry_nn->set_jvms(jvms);
    C->set_default_node_notes(entry_nn);
  }

  // Now perform the inling using the synthesized JVMState
  JVMState* new_jvms = _inline_cg->generate(jvms);
  if (new_jvms == NULL)  return;  // no change
  if (C->failing())      return;

  // Capture any exceptional control flow
  GraphKit kit(new_jvms);

  // Find the result object
  Node* result = C->top();
  int   result_size = method()->return_type()->size();
  if (result_size != 0 && !kit.stopped()) {
    result = (result_size == 1) ? kit.pop() : kit.pop_pair();
  }

  kit.replace_call(call, result);
}

JVMState* PredicatedIntrinsicGenerator::generate(JVMState* jvms) {
  // The code we want to generate here is:
  //    if (receiver == NULL)
  //        uncommon_Trap
  //    if (predicate(0))
  //        do_intrinsic(0)
  //    else
  //    if (predicate(1))
  //        do_intrinsic(1)
  //    ...
  //    else
  //        do_java_comp

  GraphKit kit(jvms);
  PhaseGVN& gvn = kit.gvn();

  CompileLog* log = kit.C->log();
  if (log != NULL) {
    log->elem("predicated_intrinsic bci='%d' method='%d'",
              jvms->bci(), log->identify(method()));
  }

  if (!method()->is_static()) {
    // We need an explicit receiver null_check before checking its type in predicate.
    // We share a map with the caller, so his JVMS gets adjusted.
    Node* receiver = kit.null_check_receiver_before_call(method());
    if (kit.stopped()) {
      return kit.transfer_exceptions_into_jvms();
    }
  }

  int n_predicates = _intrinsic->predicates_count();
  assert(n_predicates > 0, "sanity");

  JVMState** result_jvms = NEW_RESOURCE_ARRAY(JVMState*, (n_predicates+1));

  // Region for normal compilation code if intrinsic failed.
  Node* slow_region = new (kit.C) RegionNode(1);

  int results = 0;
  for (int predicate = 0; (predicate < n_predicates) && !kit.stopped(); predicate++) {
#ifdef ASSERT
    JVMState* old_jvms = kit.jvms();
    SafePointNode* old_map = kit.map();
    Node* old_io  = old_map->i_o();
    Node* old_mem = old_map->memory();
    Node* old_exc = old_map->next_exception();
#endif
    Node* else_ctrl = _intrinsic->generate_predicate(kit.sync_jvms(), predicate);
#ifdef ASSERT
    // Assert(no_new_memory && no_new_io && no_new_exceptions) after generate_predicate.
    assert(old_jvms == kit.jvms(), "generate_predicate should not change jvm state");
    SafePointNode* new_map = kit.map();
    assert(old_io  == new_map->i_o(), "generate_predicate should not change i_o");
    assert(old_mem == new_map->memory(), "generate_predicate should not change memory");
    assert(old_exc == new_map->next_exception(), "generate_predicate should not add exceptions");
#endif
    if (!kit.stopped()) {
      PreserveJVMState pjvms(&kit);
      // Generate intrinsic code:
      JVMState* new_jvms = _intrinsic->generate(kit.sync_jvms());
      if (new_jvms == NULL) {
        // Intrinsic failed, use normal compilation path for this predicate.
        slow_region->add_req(kit.control());
      } else {
        kit.add_exception_states_from(new_jvms);
        kit.set_jvms(new_jvms);
        if (!kit.stopped()) {
          result_jvms[results++] = kit.jvms();
        }
      }
    }
    if (else_ctrl == NULL) {
      else_ctrl = kit.C->top();
    }
    kit.set_control(else_ctrl);
  }
  if (!kit.stopped()) {
    // Final 'else' after predicates.
    slow_region->add_req(kit.control());
  }
  if (slow_region->req() > 1) {
    PreserveJVMState pjvms(&kit);
    // Generate normal compilation code:
    kit.set_control(gvn.transform(slow_region));
    JVMState* new_jvms = _cg->generate(kit.sync_jvms());
    if (kit.failing())
      return NULL;  // might happen because of NodeCountInliningCutoff
    assert(new_jvms != NULL, "must be");
    kit.add_exception_states_from(new_jvms);
    kit.set_jvms(new_jvms);
    if (!kit.stopped()) {
      result_jvms[results++] = kit.jvms();
    }
  }

  if (results == 0) {
    // All paths ended in uncommon traps.
    (void) kit.stop();
    return kit.transfer_exceptions_into_jvms();
//.........这里部分代码省略.........

 void set_argument(uint idx, Node* c){ map_not_null(); _map->set_argument(_map->_jvms, idx, c); }

 void ensure_stack(uint stk_size)    { map_not_null(); _map->ensure_stack(_map->_jvms, stk_size); }

 void set_local(uint idx, Node* c)   { map_not_null(); _map->set_local(   _map->_jvms, idx, c); }

 void set_stack(uint idx, Node* c)   { map_not_null(); _map->set_stack(   _map->_jvms, idx, c); }

 Node* argument(uint idx)      const { map_not_null(); return _map->argument(   _map->_jvms, idx); }

 Node* monitor_obj(uint idx)   const { map_not_null(); return _map->monitor_obj(_map->_jvms, idx); }

 Node* stack(uint idx)         const { map_not_null(); return _map->stack(      _map->_jvms, idx); }

 Node* local(uint idx)         const { map_not_null(); return _map->local(      _map->_jvms, idx); }

 Node* peek(int off=0) { map_not_null(); return _map->stack(_map->_jvms, _sp - off - 1); }

 Node* pop()           { map_not_null(); return _map->stack(_map->_jvms,--_sp); }

 void push(Node* n)    { map_not_null(); _map->set_stack(_map->_jvms,_sp++,n); }