C++ SafePointNode::set_req方法代码示例

//.........这里部分代码省略.........
    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();
  }

  if (results == 1) { // Only one path
    kit.set_jvms(result_jvms[0]);
    return kit.transfer_exceptions_into_jvms();
  }

  // Merge all paths.
  kit.C->set_has_split_ifs(true); // Has chance for split-if optimization
  RegionNode* region = new (kit.C) RegionNode(results + 1);
  Node* iophi = PhiNode::make(region, kit.i_o(), Type::ABIO);
  for (int i = 0; i < results; i++) {
    JVMState* jvms = result_jvms[i];
    int path = i + 1;
    SafePointNode* map = jvms->map();
    region->init_req(path, map->control());
    iophi->set_req(path, map->i_o());
    if (i == 0) {
      kit.set_jvms(jvms);
    } else {
      kit.merge_memory(map->merged_memory(), region, path);
    }
  }
  kit.set_control(gvn.transform(region));
  kit.set_i_o(gvn.transform(iophi));
  // Transform new memory Phis.
  for (MergeMemStream mms(kit.merged_memory()); mms.next_non_empty();) {
    Node* phi = mms.memory();
    if (phi->is_Phi() && phi->in(0) == region) {
      mms.set_memory(gvn.transform(phi));
    }
  }

  // Merge debug info.
  Node** ins = NEW_RESOURCE_ARRAY(Node*, results);
  uint tos = kit.jvms()->stkoff() + kit.sp();
  Node* map = kit.map();
  uint limit = map->req();
  for (uint i = TypeFunc::Parms; i < limit; i++) {
    // Skip unused stack slots; fast forward to monoff();
    if (i == tos) {
      i = kit.jvms()->monoff();
      if( i >= limit ) break;
    }
    Node* n = map->in(i);
    ins[0] = n;
    const Type* t = gvn.type(n);
    bool needs_phi = false;
    for (int j = 1; j < results; j++) {
      JVMState* jvms = result_jvms[j];
      Node* jmap = jvms->map();
      Node* m = NULL;
      if (jmap->req() > i) {
        m = jmap->in(i);
        if (m != n) {
          needs_phi = true;
          t = t->meet_speculative(gvn.type(m));
        }
      }
      ins[j] = m;
    }
    if (needs_phi) {
      Node* phi = PhiNode::make(region, n, t);
      for (int j = 1; j < results; j++) {
        phi->set_req(j + 1, ins[j]);
      }
      map->set_req(i, gvn.transform(phi));
    }
  }

  return kit.transfer_exceptions_into_jvms();
}

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);
}