text: /*
   * Copyright (c) 1998, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   *
   */
  
  #include "precompiled.hpp"
  #include "classfile/systemDictionary.hpp"
  #include "compiler/compileLog.hpp"
  #include "oops/objArrayKlass.hpp"
  #include "opto/addnode.hpp"
  #include "opto/memnode.hpp"
  #include "opto/mulnode.hpp"
  #include "opto/parse.hpp"
  #include "opto/rootnode.hpp"
  #include "opto/runtime.hpp"
  #include "runtime/sharedRuntime.hpp"
  
  //------------------------------make_dtrace_method_entry_exit ----------------
  // Dtrace -- record entry or exit of a method if compiled with dtrace support
  void GraphKit::make_dtrace_method_entry_exit(ciMethod* method, bool is_entry) {
    const TypeFunc *call_type    = OptoRuntime::dtrace_method_entry_exit_Type();
    address         call_address = is_entry ? CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry) :
                                              CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit);
    const char     *call_name    = is_entry ? "dtrace_method_entry" : "dtrace_method_exit";
  
    // Get base of thread-local storage area
    Node* thread = _gvn.transform( new ThreadLocalNode() );
  
    // Get method
    const TypePtr* method_type = TypeMetadataPtr::make(method);
    Node *method_node = _gvn.transform(ConNode::make(method_type));
  
    kill_dead_locals();
  
    // For some reason, this call reads only raw memory.
    const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
    make_runtime_call(RC_LEAF | RC_NARROW_MEM,
                      call_type, call_address,
                      call_name, raw_adr_type,
                      thread, method_node);
  }
  
  
  //=============================================================================
  //------------------------------do_checkcast-----------------------------------
  void Parse::do_checkcast() {
    bool will_link;
    ciKlass* klass = iter().get_klass(will_link);
  
    Node *obj = peek();
  
    // Throw uncommon trap if class is not loaded or the value we are casting
    // _from_ is not loaded, and value is not null.  If the value _is_ NULL,
    // then the checkcast does nothing.
    const TypeOopPtr *tp = _gvn.type(obj)->isa_oopptr();
    if (!will_link || (tp && tp->klass() && !tp->klass()->is_loaded())) {
      if (C->log() != NULL) {
        if (!will_link) {
          C->log()->elem("assert_null reason='checkcast' klass='%d'",
                         C->log()->identify(klass));
        }
        if (tp && tp->klass() && !tp->klass()->is_loaded()) {
          // %%% Cannot happen?
          C->log()->elem("assert_null reason='checkcast source' klass='%d'",
                         C->log()->identify(tp->klass()));
        }
      }
      null_assert(obj);
      assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
      if (!stopped()) {
        profile_null_checkcast();
      }
      return;
    }
  
    Node *res = gen_checkcast(obj, makecon(TypeKlassPtr::make(klass)) );
  
    // Pop from stack AFTER gen_checkcast because it can uncommon trap and
    // the debug info has to be correct.
    pop();
    push(res);
  }
  
  
  //------------------------------do_instanceof----------------------------------
  void Parse::do_instanceof() {
    if (stopped())  return;
    // We would like to return false if class is not loaded, emitting a
    // dependency, but Java requires instanceof to load its operand.
  
    // Throw uncommon trap if class is not loaded
    bool will_link;
    ciKlass* klass = iter().get_klass(will_link);
  
    if (!will_link) {
      if (C->log() != NULL) {
        C->log()->elem("assert_null reason='instanceof' klass='%d'",
                       C->log()->identify(klass));
      }
      null_assert(peek());
      assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
      if (!stopped()) {
        // The object is now known to be null.
        // Shortcut the effect of gen_instanceof and return "false" directly.
        pop();                   // pop the null
        push(_gvn.intcon(0));    // push false answer
      }
      return;
    }
  
    // Push the bool result back on stack
    Node* res = gen_instanceof(peek(), makecon(TypeKlassPtr::make(klass)), true);
  
    // Pop from stack AFTER gen_instanceof because it can uncommon trap.
    pop();
    push(res);
  }
  
  //------------------------------array_store_check------------------------------
  // pull array from stack and check that the store is valid
  void Parse::array_store_check() {
  
    // Shorthand access to array store elements without popping them.
    Node *obj = peek(0);
    Node *idx = peek(1);
    Node *ary = peek(2);
  
    if (_gvn.type(obj) == TypePtr::NULL_PTR) {
      // There's never a type check on null values.
      // This cutout lets us avoid the uncommon_trap(Reason_array_check)
      // below, which turns into a performance liability if the
      // gen_checkcast folds up completely.
      return;
    }
  
    // Extract the array klass type
    int klass_offset = oopDesc::klass_offset_in_bytes();
    Node* p = basic_plus_adr( ary, ary, klass_offset );
    // p's type is array-of-OOPS plus klass_offset
    Node* array_klass = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS));
    // Get the array klass
    const TypeKlassPtr *tak = _gvn.type(array_klass)->is_klassptr();
  
    // The type of array_klass is usually INexact array-of-oop.  Heroically
    // cast array_klass to EXACT array and uncommon-trap if the cast fails.
    // Make constant out of the inexact array klass, but use it only if the cast
    // succeeds.
    bool always_see_exact_class = false;
    if (MonomorphicArrayCheck
        && !too_many_traps(Deoptimization::Reason_array_check)
        && !tak->klass_is_exact()
        && tak != TypeKlassPtr::OBJECT) {
        // Regarding the fourth condition in the if-statement from above:
        //
        // If the compiler has determined that the type of array 'ary' (represented
        // by 'array_klass') is java/lang/Object, the compiler must not assume that
        // the array 'ary' is monomorphic.
        //
        // If 'ary' were of type java/lang/Object, this arraystore would have to fail,
        // because it is not possible to perform a arraystore into an object that is not
        // a "proper" array.
        //
        // Therefore, let's obtain at runtime the type of 'ary' and check if we can still
        // successfully perform the store.
        //
        // The implementation reasons for the condition are the following:
        //
        // java/lang/Object is the superclass of all arrays, but it is represented by the VM
        // as an InstanceKlass. The checks generated by gen_checkcast() (see below) expect
        // 'array_klass' to be ObjArrayKlass, which can result in invalid memory accesses.
        //
        // See issue JDK-8057622 for details.
  
      always_see_exact_class = true;
      // (If no MDO at all, hope for the best, until a trap actually occurs.)
  
      // Make a constant out of the inexact array klass
      const TypeKlassPtr *extak = tak->cast_to_exactness(true)->is_klassptr();
      Node* con = makecon(extak);
      Node* cmp = _gvn.transform(new CmpPNode( array_klass, con ));
      Node* bol = _gvn.transform(new BoolNode( cmp, BoolTest::eq ));
      Node* ctrl= control();
      { BuildCutout unless(this, bol, PROB_MAX);
        uncommon_trap(Deoptimization::Reason_array_check,
                      Deoptimization::Action_maybe_recompile,
                      tak->klass());
      }
      if (stopped()) {          // MUST uncommon-trap?
        set_control(ctrl);      // Then Don't Do It, just fall into the normal checking
      } else {                  // Cast array klass to exactness:
        // Use the exact constant value we know it is.
        replace_in_map(array_klass,con);
        CompileLog* log = C->log();
        if (log != NULL) {
          log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'",
                    log->identify(tak->klass()));
        }
        array_klass = con;      // Use cast value moving forward
      }
    }
  
    // Come here for polymorphic array klasses
  
    // Extract the array element class
    int element_klass_offset = in_bytes(ObjArrayKlass::element_klass_offset());
    Node *p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset);
    // We are allowed to use the constant type only if cast succeeded. If always_see_exact_class is true,
    // we must set a control edge from the IfTrue node created by the uncommon_trap above to the
    // LoadKlassNode.
    Node* a_e_klass = _gvn.transform(LoadKlassNode::make(_gvn, always_see_exact_class ? control() : NULL,
                                                         immutable_memory(), p2, tak));
  
    // Check (the hard way) and throw if not a subklass.
    // Result is ignored, we just need the CFG effects.
    gen_checkcast(obj, a_e_klass);
  }
  
  
  //------------------------------do_new-----------------------------------------
  void Parse::do_new() {
    kill_dead_locals();
  
    bool will_link;
    ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass();
    assert(will_link, "_new: typeflow responsibility");
  
    // Should throw an InstantiationError?
    if (klass->is_abstract() || klass->is_interface() ||
        klass->name() == ciSymbol::java_lang_Class() ||
        iter().is_unresolved_klass()) {
      uncommon_trap(Deoptimization::Reason_unhandled,
                    Deoptimization::Action_none,
                    klass);
      return;
    }
  
    if (C->needs_clinit_barrier(klass, method())) {
      clinit_barrier(klass, method());
      if (stopped())  return;
    }
  
    Node* kls = makecon(TypeKlassPtr::make(klass));
    Node* obj = new_instance(kls);
  
    // Push resultant oop onto stack
    push(obj);
  
    // Keep track of whether opportunities exist for StringBuilder
    // optimizations.
    if (OptimizeStringConcat &&
        (klass == C->env()->StringBuilder_klass() ||
         klass == C->env()->StringBuffer_klass())) {
      C->set_has_stringbuilder(true);
    }
  
    // Keep track of boxed values for EliminateAutoBox optimizations.
    if (C->eliminate_boxing() && klass->is_box_klass()) {
      C->set_has_boxed_value(true);
    }
  }
  
  #ifndef PRODUCT
  //------------------------------dump_map_adr_mem-------------------------------
  // Debug dump of the mapping from address types to MergeMemNode indices.
  void Parse::dump_map_adr_mem() const {
    tty->print_cr("--- Mapping from address types to memory Nodes ---");
    MergeMemNode *mem = map() == NULL ? NULL : (map()->memory()->is_MergeMem() ?
                                        map()->memory()->as_MergeMem() : NULL);
    for (uint i = 0; i < (uint)C->num_alias_types(); i++) {
      C->alias_type(i)->print_on(tty);
      tty->print("\t");
      // Node mapping, if any
      if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) {
        mem->in(i)->dump();
      } else {
        tty->cr();
      }
    }
  }
  
  #endif
  
  
  //=============================================================================
  //
  // parser methods for profiling
  
  
  //----------------------test_counter_against_threshold ------------------------
  void Parse::test_counter_against_threshold(Node* cnt, int limit) {
    // Test the counter against the limit and uncommon trap if greater.
  
    // This code is largely copied from the range check code in
    // array_addressing()
  
    // Test invocation count vs threshold
    Node *threshold = makecon(TypeInt::make(limit));
    Node *chk   = _gvn.transform( new CmpUNode( cnt, threshold) );
    BoolTest::mask btest = BoolTest::lt;
    Node *tst   = _gvn.transform( new BoolNode( chk, btest) );
    // Branch to failure if threshold exceeded
    { BuildCutout unless(this, tst, PROB_ALWAYS);
      uncommon_trap(Deoptimization::Reason_age,
                    Deoptimization::Action_maybe_recompile);
    }
  }
  
  //----------------------increment_and_test_invocation_counter-------------------
  void Parse::increment_and_test_invocation_counter(int limit) {
    if (!count_invocations()) return;
  
    // Get the Method* node.
    ciMethod* m = method();
    MethodCounters* counters_adr = m->ensure_method_counters();
    if (counters_adr == NULL) {
      C->record_failure("method counters allocation failed");
      return;
    }
  
    Node* ctrl = control();
    const TypePtr* adr_type = TypeRawPtr::make((address) counters_adr);
    Node *counters_node = makecon(adr_type);
    Node* adr_iic_node = basic_plus_adr(counters_node, counters_node,
      MethodCounters::interpreter_invocation_counter_offset_in_bytes());
    Node* cnt = make_load(ctrl, adr_iic_node, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
  
    test_counter_against_threshold(cnt, limit);
  
    // Add one to the counter and store
    Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
    store_to_memory(ctrl, adr_iic_node, incr, T_INT, adr_type, MemNode::unordered);
  }
  
  //----------------------------method_data_addressing---------------------------
  Node* Parse::method_data_addressing(ciMethodData* md, ciProfileData* data, ByteSize counter_offset, Node* idx, uint stride) {
    // Get offset within MethodData* of the data array
    ByteSize data_offset = MethodData::data_offset();
  
    // Get cell offset of the ProfileData within data array
    int cell_offset = md->dp_to_di(data->dp());
  
    // Add in counter_offset, the # of bytes into the ProfileData of counter or flag
    int offset = in_bytes(data_offset) + cell_offset + in_bytes(counter_offset);
  
    const TypePtr* adr_type = TypeMetadataPtr::make(md);
    Node* mdo = makecon(adr_type);
    Node* ptr = basic_plus_adr(mdo, mdo, offset);
  
    if (stride != 0) {
      Node* str = _gvn.MakeConX(stride);
      Node* scale = _gvn.transform( new MulXNode( idx, str ) );
      ptr   = _gvn.transform( new AddPNode( mdo, ptr, scale ) );
    }
  
    return ptr;
  }
  
  //--------------------------increment_md_counter_at----------------------------
  void Parse::increment_md_counter_at(ciMethodData* md, ciProfileData* data, ByteSize counter_offset, Node* idx, uint stride) {
    Node* adr_node = method_data_addressing(md, data, counter_offset, idx, stride);
  
    const TypePtr* adr_type = _gvn.type(adr_node)->is_ptr();
    Node* cnt  = make_load(NULL, adr_node, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
    Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(DataLayout::counter_increment)));
    store_to_memory(NULL, adr_node, incr, T_INT, adr_type, MemNode::unordered);
  }
  
  //--------------------------test_for_osr_md_counter_at-------------------------
  void Parse::test_for_osr_md_counter_at(ciMethodData* md, ciProfileData* data, ByteSize counter_offset, int limit) {
    Node* adr_node = method_data_addressing(md, data, counter_offset);
  
    const TypePtr* adr_type = _gvn.type(adr_node)->is_ptr();
    Node* cnt  = make_load(NULL, adr_node, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
  
    test_counter_against_threshold(cnt, limit);
  }
  
  //-------------------------------set_md_flag_at--------------------------------
  void Parse::set_md_flag_at(ciMethodData* md, ciProfileData* data, int flag_constant) {
    Node* adr_node = method_data_addressing(md, data, DataLayout::flags_offset());
  
    const TypePtr* adr_type = _gvn.type(adr_node)->is_ptr();
    Node* flags = make_load(NULL, adr_node, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
    Node* incr = _gvn.transform(new OrINode(flags, _gvn.intcon(flag_constant)));
    store_to_memory(NULL, adr_node, incr, T_INT, adr_type, MemNode::unordered);
  }
  
  //----------------------------profile_taken_branch-----------------------------
  void Parse::profile_taken_branch(int target_bci, bool force_update) {
    // This is a potential osr_site if we have a backedge.
    int cur_bci = bci();
    bool osr_site =
      (target_bci <= cur_bci) && count_invocations() && UseOnStackReplacement;
  
    // If we are going to OSR, restart at the target bytecode.
    set_bci(target_bci);
  
    // To do: factor out the the limit calculations below. These duplicate
    // the similar limit calculations in the interpreter.
  
    if (method_data_update() || force_update) {
      ciMethodData* md = method()->method_data();
      assert(md != NULL, "expected valid ciMethodData");
      ciProfileData* data = md->bci_to_data(cur_bci);
      assert(data != NULL && data->is_JumpData(), "need JumpData for taken branch");
      increment_md_counter_at(md, data, JumpData::taken_offset());
    }
  
    // In the new tiered system this is all we need to do. In the old
    // (c2 based) tiered sytem we must do the code below.
  #ifndef TIERED
    if (method_data_update()) {
      ciMethodData* md = method()->method_data();
      if (osr_site) {
        ciProfileData* data = md->bci_to_data(cur_bci);
        assert(data != NULL && data->is_JumpData(), "need JumpData for taken branch");
        int limit = (int)((int64_t)CompileThreshold
                     * (OnStackReplacePercentage - InterpreterProfilePercentage) / 100);
        test_for_osr_md_counter_at(md, data, JumpData::taken_offset(), limit);
      }
    } else {
      // With method data update off, use the invocation counter to trigger an
      // OSR compilation, as done in the interpreter.
      if (osr_site) {
        int limit = (int)((int64_t)CompileThreshold * OnStackReplacePercentage / 100);
        increment_and_test_invocation_counter(limit);
      }
    }
  #endif // TIERED
  
    // Restore the original bytecode.
    set_bci(cur_bci);
  }
  
  //--------------------------profile_not_taken_branch---------------------------
  void Parse::profile_not_taken_branch(bool force_update) {
  
    if (method_data_update() || force_update) {
      ciMethodData* md = method()->method_data();
      assert(md != NULL, "expected valid ciMethodData");
      ciProfileData* data = md->bci_to_data(bci());
      assert(data != NULL && data->is_BranchData(), "need BranchData for not taken branch");
      increment_md_counter_at(md, data, BranchData::not_taken_offset());
    }
  
  }
  
  //---------------------------------profile_call--------------------------------
  void Parse::profile_call(Node* receiver) {
    if (!method_data_update()) return;
  
    switch (bc()) {
    case Bytecodes::_invokevirtual:
    case Bytecodes::_invokeinterface:
      profile_receiver_type(receiver);
      break;
    case Bytecodes::_invokestatic:
    case Bytecodes::_invokedynamic:
    case Bytecodes::_invokespecial:
      profile_generic_call();
      break;
    default: fatal("unexpected call bytecode");
    }
  }
  
  //------------------------------profile_generic_call---------------------------
  void Parse::profile_generic_call() {
    assert(method_data_update(), "must be generating profile code");
  
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
    ciProfileData* data = md->bci_to_data(bci());
    assert(data != NULL && data->is_CounterData(), "need CounterData for not taken branch");
    increment_md_counter_at(md, data, CounterData::count_offset());
  }
  
  //-----------------------------profile_receiver_type---------------------------
  void Parse::profile_receiver_type(Node* receiver) {
    assert(method_data_update(), "must be generating profile code");
  
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
    ciProfileData* data = md->bci_to_data(bci());
    assert(data != NULL && data->is_ReceiverTypeData(), "need ReceiverTypeData here");
  
    // Skip if we aren't tracking receivers
    if (TypeProfileWidth < 1) {
      increment_md_counter_at(md, data, CounterData::count_offset());
      return;
    }
    ciReceiverTypeData* rdata = (ciReceiverTypeData*)data->as_ReceiverTypeData();
  
    Node* method_data = method_data_addressing(md, rdata, in_ByteSize(0));
  
    // Using an adr_type of TypePtr::BOTTOM to work around anti-dep problems.
    // A better solution might be to use TypeRawPtr::BOTTOM with RC_NARROW_MEM.
    make_runtime_call(RC_LEAF, OptoRuntime::profile_receiver_type_Type(),
                      CAST_FROM_FN_PTR(address,
                                       OptoRuntime::profile_receiver_type_C),
                      "profile_receiver_type_C",
                      TypePtr::BOTTOM,
                      method_data, receiver);
  }
  
  //---------------------------------profile_ret---------------------------------
  void Parse::profile_ret(int target_bci) {
    if (!method_data_update()) return;
  
    // Skip if we aren't tracking ret targets
    if (TypeProfileWidth < 1) return;
  
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
    ciProfileData* data = md->bci_to_data(bci());
    assert(data != NULL && data->is_RetData(), "need RetData for ret");
    ciRetData* ret_data = (ciRetData*)data->as_RetData();
  
    // Look for the target_bci is already in the table
    uint row;
    bool table_full = true;
    for (row = 0; row < ret_data->row_limit(); row++) {
      int key = ret_data->bci(row);
      table_full &= (key != RetData::no_bci);
      if (key == target_bci) break;
    }
  
    if (row >= ret_data->row_limit()) {
      // The target_bci was not found in the table.
      if (!table_full) {
        // XXX: Make slow call to update RetData
      }
      return;
    }
  
    // the target_bci is already in the table
    increment_md_counter_at(md, data, RetData::bci_count_offset(row));
  }
  
  //--------------------------profile_null_checkcast----------------------------
  void Parse::profile_null_checkcast() {
    // Set the null-seen flag, done in conjunction with the usual null check. We
    // never unset the flag, so this is a one-way switch.
    if (!method_data_update()) return;
  
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
    ciProfileData* data = md->bci_to_data(bci());
    assert(data != NULL && data->is_BitData(), "need BitData for checkcast");
    set_md_flag_at(md, data, BitData::null_seen_byte_constant());
  }
  
  //-----------------------------profile_switch_case-----------------------------
  void Parse::profile_switch_case(int table_index) {
    if (!method_data_update()) return;
  
    ciMethodData* md = method()->method_data();
    assert(md != NULL, "expected valid ciMethodData");
  
    ciProfileData* data = md->bci_to_data(bci());
    assert(data != NULL && data->is_MultiBranchData(), "need MultiBranchData for switch case");
    if (table_index >= 0) {
      increment_md_counter_at(md, data, MultiBranchData::case_count_offset(table_index));
    } else {
      increment_md_counter_at(md, data, MultiBranchData::default_count_offset());
    }
  }
  