JVMState* PredictedIntrinsicGenerator::generate(JVMState* jvms, Parse* parent_parser) {
  GraphKit kit(jvms);
  PhaseGVN& gvn = kit.gvn();

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

  Node* slow_ctl = _intrinsic->generate_predicate(kit.sync_jvms());
  if (kit.failing())
    return NULL;  // might happen because of NodeCountInliningCutoff

  SafePointNode* slow_map = NULL;
  JVMState* slow_jvms;
  if (slow_ctl != NULL) {
    PreserveJVMState pjvms(&kit);
    kit.set_control(slow_ctl);
    if (!kit.stopped()) {
      slow_jvms = _cg->generate(kit.sync_jvms(), parent_parser);
      if (kit.failing())
        return NULL;  // might happen because of NodeCountInliningCutoff
      assert(slow_jvms != NULL, "must be");
      kit.add_exception_states_from(slow_jvms);
      kit.set_map(slow_jvms->map());
      if (!kit.stopped())
        slow_map = kit.stop();
    }
  }

  if (kit.stopped()) {
    // Predicate is always false.
    kit.set_jvms(slow_jvms);
    return kit.transfer_exceptions_into_jvms();
  }

  // Generate intrinsic code:
  JVMState* new_jvms = _intrinsic->generate(kit.sync_jvms(), parent_parser);
  if (new_jvms == NULL) {
    // Intrinsic failed, so use slow code or make a direct call.
    if (slow_map == NULL) {
      CallGenerator* cg = CallGenerator::for_direct_call(method());
      new_jvms = cg->generate(kit.sync_jvms(), parent_parser);
    } else {
      kit.set_jvms(slow_jvms);
      return kit.transfer_exceptions_into_jvms();
    }
  }
  kit.add_exception_states_from(new_jvms);
  kit.set_jvms(new_jvms);

  // Need to merge slow and fast?
  if (slow_map == NULL) {
    // The fast path is the only path remaining.
    return kit.transfer_exceptions_into_jvms();
  }

  if (kit.stopped()) {
    // Intrinsic method threw an exception, so it's just the slow path after all.
    kit.set_jvms(slow_jvms);
    return kit.transfer_exceptions_into_jvms();
  }

  // Finish the diamond.
  kit.C->set_has_split_ifs(true); // Has chance for split-if optimization
  RegionNode* region = new (kit.C) RegionNode(3);
  region->init_req(1, kit.control());
  region->init_req(2, slow_map->control());
  kit.set_control(gvn.transform(region));
  Node* iophi = PhiNode::make(region, kit.i_o(), Type::ABIO);
  iophi->set_req(2, slow_map->i_o());
  kit.set_i_o(gvn.transform(iophi));
  kit.merge_memory(slow_map->merged_memory(), region, 2);
  uint tos = kit.jvms()->stkoff() + kit.sp();
  uint limit = slow_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* m = kit.map()->in(i);
    Node* n = slow_map->in(i);
    if (m != n) {
      const Type* t = gvn.type(m)->meet(gvn.type(n));
      Node* phi = PhiNode::make(region, m, t);
      phi->set_req(2, n);
      kit.map()->set_req(i, gvn.transform(phi));
    }
  }
  return kit.transfer_exceptions_into_jvms();
}
Beispiel #2
0
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();
  }

  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();
}