view src/share/vm/opto/graphKit.cpp @ 2352:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents 9dc311b8473e
children 92add02409c9
line wrap: on
line source
/*
 * Copyright (c) 2001, 2011, 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 "compiler/compileLog.hpp"
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/heapRegion.hpp"
#include "gc_interface/collectedHeap.hpp"
#include "memory/barrierSet.hpp"
#include "memory/cardTableModRefBS.hpp"
#include "opto/addnode.hpp"
#include "opto/graphKit.hpp"
#include "opto/idealKit.hpp"
#include "opto/locknode.hpp"
#include "opto/machnode.hpp"
#include "opto/parse.hpp"
#include "opto/rootnode.hpp"
#include "opto/runtime.hpp"
#include "runtime/deoptimization.hpp"
#include "runtime/sharedRuntime.hpp"

//----------------------------GraphKit-----------------------------------------
// Main utility constructor.
GraphKit::GraphKit(JVMState* jvms)
  : Phase(Phase::Parser),
    _env(C->env()),
    _gvn(*C->initial_gvn())
{
  _exceptions = jvms->map()->next_exception();
  if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  set_jvms(jvms);
}

// Private constructor for parser.
GraphKit::GraphKit()
  : Phase(Phase::Parser),
    _env(C->env()),
    _gvn(*C->initial_gvn())
{
  _exceptions = NULL;
  set_map(NULL);
  debug_only(_sp = -99);
  debug_only(set_bci(-99));
}



//---------------------------clean_stack---------------------------------------
// Clear away rubbish from the stack area of the JVM state.
// This destroys any arguments that may be waiting on the stack.
void GraphKit::clean_stack(int from_sp) {
  SafePointNode* map      = this->map();
  JVMState*      jvms     = this->jvms();
  int            stk_size = jvms->stk_size();
  int            stkoff   = jvms->stkoff();
  Node*          top      = this->top();
  for (int i = from_sp; i < stk_size; i++) {
    if (map->in(stkoff + i) != top) {
      map->set_req(stkoff + i, top);
    }
  }
}


//--------------------------------sync_jvms-----------------------------------
// Make sure our current jvms agrees with our parse state.
JVMState* GraphKit::sync_jvms() const {
  JVMState* jvms = this->jvms();
  jvms->set_bci(bci());       // Record the new bci in the JVMState
  jvms->set_sp(sp());         // Record the new sp in the JVMState
  assert(jvms_in_sync(), "jvms is now in sync");
  return jvms;
}

#ifdef ASSERT
bool GraphKit::jvms_in_sync() const {
  Parse* parse = is_Parse();
  if (parse == NULL) {
    if (bci() !=      jvms()->bci())          return false;
    if (sp()  != (int)jvms()->sp())           return false;
    return true;
  }
  if (jvms()->method() != parse->method())    return false;
  if (jvms()->bci()    != parse->bci())       return false;
  int jvms_sp = jvms()->sp();
  if (jvms_sp          != parse->sp())        return false;
  int jvms_depth = jvms()->depth();
  if (jvms_depth       != parse->depth())     return false;
  return true;
}

// Local helper checks for special internal merge points
// used to accumulate and merge exception states.
// They are marked by the region's in(0) edge being the map itself.
// Such merge points must never "escape" into the parser at large,
// until they have been handed to gvn.transform.
static bool is_hidden_merge(Node* reg) {
  if (reg == NULL)  return false;
  if (reg->is_Phi()) {
    reg = reg->in(0);
    if (reg == NULL)  return false;
  }
  return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
}

void GraphKit::verify_map() const {
  if (map() == NULL)  return;  // null map is OK
  assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
  assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
  assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
}

void GraphKit::verify_exception_state(SafePointNode* ex_map) {
  assert(ex_map->next_exception() == NULL, "not already part of a chain");
  assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
}
#endif

//---------------------------stop_and_kill_map---------------------------------
// Set _map to NULL, signalling a stop to further bytecode execution.
// First smash the current map's control to a constant, to mark it dead.
void GraphKit::stop_and_kill_map() {
  SafePointNode* dead_map = stop();
  if (dead_map != NULL) {
    dead_map->disconnect_inputs(NULL); // Mark the map as killed.
    assert(dead_map->is_killed(), "must be so marked");
  }
}


//--------------------------------stopped--------------------------------------
// Tell if _map is NULL, or control is top.
bool GraphKit::stopped() {
  if (map() == NULL)           return true;
  else if (control() == top()) return true;
  else                         return false;
}


//-----------------------------has_ex_handler----------------------------------
// Tell if this method or any caller method has exception handlers.
bool GraphKit::has_ex_handler() {
  for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
    if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
      return true;
    }
  }
  return false;
}

//------------------------------save_ex_oop------------------------------------
// Save an exception without blowing stack contents or other JVM state.
void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
  assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
  ex_map->add_req(ex_oop);
  debug_only(verify_exception_state(ex_map));
}

inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
  assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
  Node* ex_oop = ex_map->in(ex_map->req()-1);
  if (clear_it)  ex_map->del_req(ex_map->req()-1);
  return ex_oop;
}

//-----------------------------saved_ex_oop------------------------------------
// Recover a saved exception from its map.
Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
  return common_saved_ex_oop(ex_map, false);
}

//--------------------------clear_saved_ex_oop---------------------------------
// Erase a previously saved exception from its map.
Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
  return common_saved_ex_oop(ex_map, true);
}

#ifdef ASSERT
//---------------------------has_saved_ex_oop----------------------------------
// Erase a previously saved exception from its map.
bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
  return ex_map->req() == ex_map->jvms()->endoff()+1;
}
#endif

//-------------------------make_exception_state--------------------------------
// Turn the current JVM state into an exception state, appending the ex_oop.
SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
  sync_jvms();
  SafePointNode* ex_map = stop();  // do not manipulate this map any more
  set_saved_ex_oop(ex_map, ex_oop);
  return ex_map;
}


//--------------------------add_exception_state--------------------------------
// Add an exception to my list of exceptions.
void GraphKit::add_exception_state(SafePointNode* ex_map) {
  if (ex_map == NULL || ex_map->control() == top()) {
    return;
  }
#ifdef ASSERT
  verify_exception_state(ex_map);
  if (has_exceptions()) {
    assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
  }
#endif

  // If there is already an exception of exactly this type, merge with it.
  // In particular, null-checks and other low-level exceptions common up here.
  Node*       ex_oop  = saved_ex_oop(ex_map);
  const Type* ex_type = _gvn.type(ex_oop);
  if (ex_oop == top()) {
    // No action needed.
    return;
  }
  assert(ex_type->isa_instptr(), "exception must be an instance");
  for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
    const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
    // We check sp also because call bytecodes can generate exceptions
    // both before and after arguments are popped!
    if (ex_type2 == ex_type
        && e2->_jvms->sp() == ex_map->_jvms->sp()) {
      combine_exception_states(ex_map, e2);
      return;
    }
  }

  // No pre-existing exception of the same type.  Chain it on the list.
  push_exception_state(ex_map);
}

//-----------------------add_exception_states_from-----------------------------
void GraphKit::add_exception_states_from(JVMState* jvms) {
  SafePointNode* ex_map = jvms->map()->next_exception();
  if (ex_map != NULL) {
    jvms->map()->set_next_exception(NULL);
    for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
      next_map = ex_map->next_exception();
      ex_map->set_next_exception(NULL);
      add_exception_state(ex_map);
    }
  }
}

//-----------------------transfer_exceptions_into_jvms-------------------------
JVMState* GraphKit::transfer_exceptions_into_jvms() {
  if (map() == NULL) {
    // We need a JVMS to carry the exceptions, but the map has gone away.
    // Create a scratch JVMS, cloned from any of the exception states...
    if (has_exceptions()) {
      _map = _exceptions;
      _map = clone_map();
      _map->set_next_exception(NULL);
      clear_saved_ex_oop(_map);
      debug_only(verify_map());
    } else {
      // ...or created from scratch
      JVMState* jvms = new (C) JVMState(_method, NULL);
      jvms->set_bci(_bci);
      jvms->set_sp(_sp);
      jvms->set_map(new (C, TypeFunc::Parms) SafePointNode(TypeFunc::Parms, jvms));
      set_jvms(jvms);
      for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
      set_all_memory(top());
      while (map()->req() < jvms->endoff())  map()->add_req(top());
    }
    // (This is a kludge, in case you didn't notice.)
    set_control(top());
  }
  JVMState* jvms = sync_jvms();
  assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
  jvms->map()->set_next_exception(_exceptions);
  _exceptions = NULL;   // done with this set of exceptions
  return jvms;
}

static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
  assert(is_hidden_merge(dstphi), "must be a special merge node");
  assert(is_hidden_merge(srcphi), "must be a special merge node");
  uint limit = srcphi->req();
  for (uint i = PhiNode::Input; i < limit; i++) {
    dstphi->add_req(srcphi->in(i));
  }
}
static inline void add_one_req(Node* dstphi, Node* src) {
  assert(is_hidden_merge(dstphi), "must be a special merge node");
  assert(!is_hidden_merge(src), "must not be a special merge node");
  dstphi->add_req(src);
}

//-----------------------combine_exception_states------------------------------
// This helper function combines exception states by building phis on a
// specially marked state-merging region.  These regions and phis are
// untransformed, and can build up gradually.  The region is marked by
// having a control input of its exception map, rather than NULL.  Such
// regions do not appear except in this function, and in use_exception_state.
void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
  if (failing())  return;  // dying anyway...
  JVMState* ex_jvms = ex_map->_jvms;
  assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
  assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
  assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
  assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
  assert(ex_map->req() == phi_map->req(), "matching maps");
  uint tos = ex_jvms->stkoff() + ex_jvms->sp();
  Node*         hidden_merge_mark = root();
  Node*         region  = phi_map->control();
  MergeMemNode* phi_mem = phi_map->merged_memory();
  MergeMemNode* ex_mem  = ex_map->merged_memory();
  if (region->in(0) != hidden_merge_mark) {
    // The control input is not (yet) a specially-marked region in phi_map.
    // Make it so, and build some phis.
    region = new (C, 2) RegionNode(2);
    _gvn.set_type(region, Type::CONTROL);
    region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
    region->init_req(1, phi_map->control());
    phi_map->set_control(region);
    Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
    record_for_igvn(io_phi);
    _gvn.set_type(io_phi, Type::ABIO);
    phi_map->set_i_o(io_phi);
    for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
      Node* m = mms.memory();
      Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
      record_for_igvn(m_phi);
      _gvn.set_type(m_phi, Type::MEMORY);
      mms.set_memory(m_phi);
    }
  }

  // Either or both of phi_map and ex_map might already be converted into phis.
  Node* ex_control = ex_map->control();
  // if there is special marking on ex_map also, we add multiple edges from src
  bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
  // how wide was the destination phi_map, originally?
  uint orig_width = region->req();

  if (add_multiple) {
    add_n_reqs(region, ex_control);
    add_n_reqs(phi_map->i_o(), ex_map->i_o());
  } else {
    // ex_map has no merges, so we just add single edges everywhere
    add_one_req(region, ex_control);
    add_one_req(phi_map->i_o(), ex_map->i_o());
  }
  for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
    if (mms.is_empty()) {
      // get a copy of the base memory, and patch some inputs into it
      const TypePtr* adr_type = mms.adr_type(C);
      Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
      assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
      mms.set_memory(phi);
      // Prepare to append interesting stuff onto the newly sliced phi:
      while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
    }
    // Append stuff from ex_map:
    if (add_multiple) {
      add_n_reqs(mms.memory(), mms.memory2());
    } else {
      add_one_req(mms.memory(), mms.memory2());
    }
  }
  uint limit = ex_map->req();
  for (uint i = TypeFunc::Parms; i < limit; i++) {
    // Skip everything in the JVMS after tos.  (The ex_oop follows.)
    if (i == tos)  i = ex_jvms->monoff();
    Node* src = ex_map->in(i);
    Node* dst = phi_map->in(i);
    if (src != dst) {
      PhiNode* phi;
      if (dst->in(0) != region) {
        dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
        record_for_igvn(phi);
        _gvn.set_type(phi, phi->type());
        phi_map->set_req(i, dst);
        // Prepare to append interesting stuff onto the new phi:
        while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
      } else {
        assert(dst->is_Phi(), "nobody else uses a hidden region");
        phi = (PhiNode*)dst;
      }
      if (add_multiple && src->in(0) == ex_control) {
        // Both are phis.
        add_n_reqs(dst, src);
      } else {
        while (dst->req() < region->req())  add_one_req(dst, src);
      }
      const Type* srctype = _gvn.type(src);
      if (phi->type() != srctype) {
        const Type* dsttype = phi->type()->meet(srctype);
        if (phi->type() != dsttype) {
          phi->set_type(dsttype);
          _gvn.set_type(phi, dsttype);
        }
      }
    }
  }
}

//--------------------------use_exception_state--------------------------------
Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
  if (failing()) { stop(); return top(); }
  Node* region = phi_map->control();
  Node* hidden_merge_mark = root();
  assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
  Node* ex_oop = clear_saved_ex_oop(phi_map);
  if (region->in(0) == hidden_merge_mark) {
    // Special marking for internal ex-states.  Process the phis now.
    region->set_req(0, region);  // now it's an ordinary region
    set_jvms(phi_map->jvms());   // ...so now we can use it as a map
    // Note: Setting the jvms also sets the bci and sp.
    set_control(_gvn.transform(region));
    uint tos = jvms()->stkoff() + sp();
    for (uint i = 1; i < tos; i++) {
      Node* x = phi_map->in(i);
      if (x->in(0) == region) {
        assert(x->is_Phi(), "expected a special phi");
        phi_map->set_req(i, _gvn.transform(x));
      }
    }
    for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
      Node* x = mms.memory();
      if (x->in(0) == region) {
        assert(x->is_Phi(), "nobody else uses a hidden region");
        mms.set_memory(_gvn.transform(x));
      }
    }
    if (ex_oop->in(0) == region) {
      assert(ex_oop->is_Phi(), "expected a special phi");
      ex_oop = _gvn.transform(ex_oop);
    }
  } else {
    set_jvms(phi_map->jvms());
  }

  assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
  assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
  return ex_oop;
}

//---------------------------------java_bc-------------------------------------
Bytecodes::Code GraphKit::java_bc() const {
  ciMethod* method = this->method();
  int       bci    = this->bci();
  if (method != NULL && bci != InvocationEntryBci)
    return method->java_code_at_bci(bci);
  else
    return Bytecodes::_illegal;
}

void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
                                                          bool must_throw) {
    // if the exception capability is set, then we will generate code
    // to check the JavaThread.should_post_on_exceptions flag to see
    // if we actually need to report exception events (for this
    // thread).  If we don't need to report exception events, we will
    // take the normal fast path provided by add_exception_events.  If
    // exception event reporting is enabled for this thread, we will
    // take the uncommon_trap in the BuildCutout below.

    // first must access the should_post_on_exceptions_flag in this thread's JavaThread
    Node* jthread = _gvn.transform(new (C, 1) ThreadLocalNode());
    Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
    Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, false);

    // Test the should_post_on_exceptions_flag vs. 0
    Node* chk = _gvn.transform( new (C, 3) CmpINode(should_post_flag, intcon(0)) );
    Node* tst = _gvn.transform( new (C, 2) BoolNode(chk, BoolTest::eq) );

    // Branch to slow_path if should_post_on_exceptions_flag was true
    { BuildCutout unless(this, tst, PROB_MAX);
      // Do not try anything fancy if we're notifying the VM on every throw.
      // Cf. case Bytecodes::_athrow in parse2.cpp.
      uncommon_trap(reason, Deoptimization::Action_none,
                    (ciKlass*)NULL, (char*)NULL, must_throw);
    }

}

//------------------------------builtin_throw----------------------------------
void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
  bool must_throw = true;

  if (env()->jvmti_can_post_on_exceptions()) {
    // check if we must post exception events, take uncommon trap if so
    uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
    // here if should_post_on_exceptions is false
    // continue on with the normal codegen
  }

  // If this particular condition has not yet happened at this
  // bytecode, then use the uncommon trap mechanism, and allow for
  // a future recompilation if several traps occur here.
  // If the throw is hot, try to use a more complicated inline mechanism
  // which keeps execution inside the compiled code.
  bool treat_throw_as_hot = false;
  ciMethodData* md = method()->method_data();

  if (ProfileTraps) {
    if (too_many_traps(reason)) {
      treat_throw_as_hot = true;
    }
    // (If there is no MDO at all, assume it is early in
    // execution, and that any deopts are part of the
    // startup transient, and don't need to be remembered.)

    // Also, if there is a local exception handler, treat all throws
    // as hot if there has been at least one in this method.
    if (C->trap_count(reason) != 0
        && method()->method_data()->trap_count(reason) != 0
        && has_ex_handler()) {
        treat_throw_as_hot = true;
    }
  }

  // If this throw happens frequently, an uncommon trap might cause
  // a performance pothole.  If there is a local exception handler,
  // and if this particular bytecode appears to be deoptimizing often,
  // let us handle the throw inline, with a preconstructed instance.
  // Note:   If the deopt count has blown up, the uncommon trap
  // runtime is going to flush this nmethod, not matter what.
  if (treat_throw_as_hot
      && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
    // If the throw is local, we use a pre-existing instance and
    // punt on the backtrace.  This would lead to a missing backtrace
    // (a repeat of 4292742) if the backtrace object is ever asked
    // for its backtrace.
    // Fixing this remaining case of 4292742 requires some flavor of
    // escape analysis.  Leave that for the future.
    ciInstance* ex_obj = NULL;
    switch (reason) {
    case Deoptimization::Reason_null_check:
      ex_obj = env()->NullPointerException_instance();
      break;
    case Deoptimization::Reason_div0_check:
      ex_obj = env()->ArithmeticException_instance();
      break;
    case Deoptimization::Reason_range_check:
      ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
      break;
    case Deoptimization::Reason_class_check:
      if (java_bc() == Bytecodes::_aastore) {
        ex_obj = env()->ArrayStoreException_instance();
      } else {
        ex_obj = env()->ClassCastException_instance();
      }
      break;
    }
    if (failing()) { stop(); return; }  // exception allocation might fail
    if (ex_obj != NULL) {
      // Cheat with a preallocated exception object.
      if (C->log() != NULL)
        C->log()->elem("hot_throw preallocated='1' reason='%s'",
                       Deoptimization::trap_reason_name(reason));
      const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
      Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );

      // Clear the detail message of the preallocated exception object.
      // Weblogic sometimes mutates the detail message of exceptions
      // using reflection.
      int offset = java_lang_Throwable::get_detailMessage_offset();
      const TypePtr* adr_typ = ex_con->add_offset(offset);

      Node *adr = basic_plus_adr(ex_node, ex_node, offset);
      const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
      Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT);

      add_exception_state(make_exception_state(ex_node));
      return;
    }
  }

  // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
  // It won't be much cheaper than bailing to the interp., since we'll
  // have to pass up all the debug-info, and the runtime will have to
  // create the stack trace.

  // Usual case:  Bail to interpreter.
  // Reserve the right to recompile if we haven't seen anything yet.

  Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
  if (treat_throw_as_hot
      && (method()->method_data()->trap_recompiled_at(bci())
          || C->too_many_traps(reason))) {
    // We cannot afford to take more traps here.  Suffer in the interpreter.
    if (C->log() != NULL)
      C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
                     Deoptimization::trap_reason_name(reason),
                     C->trap_count(reason));
    action = Deoptimization::Action_none;
  }

  // "must_throw" prunes the JVM state to include only the stack, if there
  // are no local exception handlers.  This should cut down on register
  // allocation time and code size, by drastically reducing the number
  // of in-edges on the call to the uncommon trap.

  uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
}


//----------------------------PreserveJVMState---------------------------------
PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
  debug_only(kit->verify_map());
  _kit    = kit;
  _map    = kit->map();   // preserve the map
  _sp     = kit->sp();
  kit->set_map(clone_map ? kit->clone_map() : NULL);
#ifdef ASSERT
  _bci    = kit->bci();
  Parse* parser = kit->is_Parse();
  int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
  _block  = block;
#endif
}
PreserveJVMState::~PreserveJVMState() {
  GraphKit* kit = _kit;
#ifdef ASSERT
  assert(kit->bci() == _bci, "bci must not shift");
  Parse* parser = kit->is_Parse();
  int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
  assert(block == _block,    "block must not shift");
#endif
  kit->set_map(_map);
  kit->set_sp(_sp);
}


//-----------------------------BuildCutout-------------------------------------
BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
  : PreserveJVMState(kit)
{
  assert(p->is_Con() || p->is_Bool(), "test must be a bool");
  SafePointNode* outer_map = _map;   // preserved map is caller's
  SafePointNode* inner_map = kit->map();
  IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
  outer_map->set_control(kit->gvn().transform( new (kit->C, 1) IfTrueNode(iff) ));
  inner_map->set_control(kit->gvn().transform( new (kit->C, 1) IfFalseNode(iff) ));
}
BuildCutout::~BuildCutout() {
  GraphKit* kit = _kit;
  assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
}

//---------------------------PreserveReexecuteState----------------------------
PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
  assert(!kit->stopped(), "must call stopped() before");
  _kit    =    kit;
  _sp     =    kit->sp();
  _reexecute = kit->jvms()->_reexecute;
}
PreserveReexecuteState::~PreserveReexecuteState() {
  if (_kit->stopped()) return;
  _kit->jvms()->_reexecute = _reexecute;
  _kit->set_sp(_sp);
}

//------------------------------clone_map--------------------------------------
// Implementation of PreserveJVMState
//
// Only clone_map(...) here. If this function is only used in the
// PreserveJVMState class we may want to get rid of this extra
// function eventually and do it all there.

SafePointNode* GraphKit::clone_map() {
  if (map() == NULL)  return NULL;

  // Clone the memory edge first
  Node* mem = MergeMemNode::make(C, map()->memory());
  gvn().set_type_bottom(mem);

  SafePointNode *clonemap = (SafePointNode*)map()->clone();
  JVMState* jvms = this->jvms();
  JVMState* clonejvms = jvms->clone_shallow(C);
  clonemap->set_memory(mem);
  clonemap->set_jvms(clonejvms);
  clonejvms->set_map(clonemap);
  record_for_igvn(clonemap);
  gvn().set_type_bottom(clonemap);
  return clonemap;
}


//-----------------------------set_map_clone-----------------------------------
void GraphKit::set_map_clone(SafePointNode* m) {
  _map = m;
  _map = clone_map();
  _map->set_next_exception(NULL);
  debug_only(verify_map());
}


//----------------------------kill_dead_locals---------------------------------
// Detect any locals which are known to be dead, and force them to top.
void GraphKit::kill_dead_locals() {
  // Consult the liveness information for the locals.  If any
  // of them are unused, then they can be replaced by top().  This
  // should help register allocation time and cut down on the size
  // of the deoptimization information.

  // This call is made from many of the bytecode handling
  // subroutines called from the Big Switch in do_one_bytecode.
  // Every bytecode which might include a slow path is responsible
  // for killing its dead locals.  The more consistent we
  // are about killing deads, the fewer useless phis will be
  // constructed for them at various merge points.

  // bci can be -1 (InvocationEntryBci).  We return the entry
  // liveness for the method.

  if (method() == NULL || method()->code_size() == 0) {
    // We are building a graph for a call to a native method.
    // All locals are live.
    return;
  }

  ResourceMark rm;

  // Consult the liveness information for the locals.  If any
  // of them are unused, then they can be replaced by top().  This
  // should help register allocation time and cut down on the size
  // of the deoptimization information.
  MethodLivenessResult live_locals = method()->liveness_at_bci(bci());

  int len = (int)live_locals.size();
  assert(len <= jvms()->loc_size(), "too many live locals");
  for (int local = 0; local < len; local++) {
    if (!live_locals.at(local)) {
      set_local(local, top());
    }
  }
}

#ifdef ASSERT
//-------------------------dead_locals_are_killed------------------------------
// Return true if all dead locals are set to top in the map.
// Used to assert "clean" debug info at various points.
bool GraphKit::dead_locals_are_killed() {
  if (method() == NULL || method()->code_size() == 0) {
    // No locals need to be dead, so all is as it should be.
    return true;
  }

  // Make sure somebody called kill_dead_locals upstream.
  ResourceMark rm;
  for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
    if (jvms->loc_size() == 0)  continue;  // no locals to consult
    SafePointNode* map = jvms->map();
    ciMethod* method = jvms->method();
    int       bci    = jvms->bci();
    if (jvms == this->jvms()) {
      bci = this->bci();  // it might not yet be synched
    }
    MethodLivenessResult live_locals = method->liveness_at_bci(bci);
    int len = (int)live_locals.size();
    if (!live_locals.is_valid() || len == 0)
      // This method is trivial, or is poisoned by a breakpoint.
      return true;
    assert(len == jvms->loc_size(), "live map consistent with locals map");
    for (int local = 0; local < len; local++) {
      if (!live_locals.at(local) && map->local(jvms, local) != top()) {
        if (PrintMiscellaneous && (Verbose || WizardMode)) {
          tty->print_cr("Zombie local %d: ", local);
          jvms->dump();
        }
        return false;
      }
    }
  }
  return true;
}

#endif //ASSERT

// Helper function for enforcing certain bytecodes to reexecute if
// deoptimization happens
static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
  ciMethod* cur_method = jvms->method();
  int       cur_bci   = jvms->bci();
  if (cur_method != NULL && cur_bci != InvocationEntryBci) {
    Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
    return Interpreter::bytecode_should_reexecute(code) ||
           is_anewarray && code == Bytecodes::_multianewarray;
    // Reexecute _multianewarray bytecode which was replaced with
    // sequence of [a]newarray. See Parse::do_multianewarray().
    //
    // Note: interpreter should not have it set since this optimization
    // is limited by dimensions and guarded by flag so in some cases
    // multianewarray() runtime calls will be generated and
    // the bytecode should not be reexecutes (stack will not be reset).
  } else
    return false;
}

// Helper function for adding JVMState and debug information to node
void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
  // Add the safepoint edges to the call (or other safepoint).

  // Make sure dead locals are set to top.  This
  // should help register allocation time and cut down on the size
  // of the deoptimization information.
  assert(dead_locals_are_killed(), "garbage in debug info before safepoint");

  // Walk the inline list to fill in the correct set of JVMState's
  // Also fill in the associated edges for each JVMState.

  JVMState* youngest_jvms = sync_jvms();

  // If we are guaranteed to throw, we can prune everything but the
  // input to the current bytecode.
  bool can_prune_locals = false;
  uint stack_slots_not_pruned = 0;
  int inputs = 0, depth = 0;
  if (must_throw) {
    assert(method() == youngest_jvms->method(), "sanity");
    if (compute_stack_effects(inputs, depth)) {
      can_prune_locals = true;
      stack_slots_not_pruned = inputs;
    }
  }

  if (env()->jvmti_can_access_local_variables()) {
    // At any safepoint, this method can get breakpointed, which would
    // then require an immediate deoptimization.
    can_prune_locals = false;  // do not prune locals
    stack_slots_not_pruned = 0;
  }

  // do not scribble on the input jvms
  JVMState* out_jvms = youngest_jvms->clone_deep(C);
  call->set_jvms(out_jvms); // Start jvms list for call node

  // For a known set of bytecodes, the interpreter should reexecute them if
  // deoptimization happens. We set the reexecute state for them here
  if (out_jvms->is_reexecute_undefined() && //don't change if already specified
      should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
    out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
  }

  // Presize the call:
  debug_only(uint non_debug_edges = call->req());
  call->add_req_batch(top(), youngest_jvms->debug_depth());
  assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");

  // Set up edges so that the call looks like this:
  //  Call [state:] ctl io mem fptr retadr
  //       [parms:] parm0 ... parmN
  //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
  //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
  //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
  // Note that caller debug info precedes callee debug info.

  // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
  uint debug_ptr = call->req();

  // Loop over the map input edges associated with jvms, add them
  // to the call node, & reset all offsets to match call node array.
  for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
    uint debug_end   = debug_ptr;
    uint debug_start = debug_ptr - in_jvms->debug_size();
    debug_ptr = debug_start;  // back up the ptr

    uint p = debug_start;  // walks forward in [debug_start, debug_end)
    uint j, k, l;
    SafePointNode* in_map = in_jvms->map();
    out_jvms->set_map(call);

    if (can_prune_locals) {
      assert(in_jvms->method() == out_jvms->method(), "sanity");
      // If the current throw can reach an exception handler in this JVMS,
      // then we must keep everything live that can reach that handler.
      // As a quick and dirty approximation, we look for any handlers at all.
      if (in_jvms->method()->has_exception_handlers()) {
        can_prune_locals = false;
      }
    }

    // Add the Locals
    k = in_jvms->locoff();
    l = in_jvms->loc_size();
    out_jvms->set_locoff(p);
    if (!can_prune_locals) {
      for (j = 0; j < l; j++)
        call->set_req(p++, in_map->in(k+j));
    } else {
      p += l;  // already set to top above by add_req_batch
    }

    // Add the Expression Stack
    k = in_jvms->stkoff();
    l = in_jvms->sp();
    out_jvms->set_stkoff(p);
    if (!can_prune_locals) {
      for (j = 0; j < l; j++)
        call->set_req(p++, in_map->in(k+j));
    } else if (can_prune_locals && stack_slots_not_pruned != 0) {
      // Divide stack into {S0,...,S1}, where S0 is set to top.
      uint s1 = stack_slots_not_pruned;
      stack_slots_not_pruned = 0;  // for next iteration
      if (s1 > l)  s1 = l;
      uint s0 = l - s1;
      p += s0;  // skip the tops preinstalled by add_req_batch
      for (j = s0; j < l; j++)
        call->set_req(p++, in_map->in(k+j));
    } else {
      p += l;  // already set to top above by add_req_batch
    }

    // Add the Monitors
    k = in_jvms->monoff();
    l = in_jvms->mon_size();
    out_jvms->set_monoff(p);
    for (j = 0; j < l; j++)
      call->set_req(p++, in_map->in(k+j));

    // Copy any scalar object fields.
    k = in_jvms->scloff();
    l = in_jvms->scl_size();
    out_jvms->set_scloff(p);
    for (j = 0; j < l; j++)
      call->set_req(p++, in_map->in(k+j));

    // Finish the new jvms.
    out_jvms->set_endoff(p);

    assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
    assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
    assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
    assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
    assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
    assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");

    // Update the two tail pointers in parallel.
    out_jvms = out_jvms->caller();
    in_jvms  = in_jvms->caller();
  }

  assert(debug_ptr == non_debug_edges, "debug info must fit exactly");

  // Test the correctness of JVMState::debug_xxx accessors:
  assert(call->jvms()->debug_start() == non_debug_edges, "");
  assert(call->jvms()->debug_end()   == call->req(), "");
  assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
}

bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
  Bytecodes::Code code = java_bc();
  if (code == Bytecodes::_wide) {
    code = method()->java_code_at_bci(bci() + 1);
  }

  BasicType rtype = T_ILLEGAL;
  int       rsize = 0;

  if (code != Bytecodes::_illegal) {
    depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
    rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
    if (rtype < T_CONFLICT)
      rsize = type2size[rtype];
  }

  switch (code) {
  case Bytecodes::_illegal:
    return false;

  case Bytecodes::_ldc:
  case Bytecodes::_ldc_w:
  case Bytecodes::_ldc2_w:
    inputs = 0;
    break;

  case Bytecodes::_dup:         inputs = 1;  break;
  case Bytecodes::_dup_x1:      inputs = 2;  break;
  case Bytecodes::_dup_x2:      inputs = 3;  break;
  case Bytecodes::_dup2:        inputs = 2;  break;
  case Bytecodes::_dup2_x1:     inputs = 3;  break;
  case Bytecodes::_dup2_x2:     inputs = 4;  break;
  case Bytecodes::_swap:        inputs = 2;  break;
  case Bytecodes::_arraylength: inputs = 1;  break;

  case Bytecodes::_getstatic:
  case Bytecodes::_putstatic:
  case Bytecodes::_getfield:
  case Bytecodes::_putfield:
    {
      bool is_get = (depth >= 0), is_static = (depth & 1);
      bool ignore;
      ciBytecodeStream iter(method());
      iter.reset_to_bci(bci());
      iter.next();
      ciField* field = iter.get_field(ignore);
      int      size  = field->type()->size();
      inputs  = (is_static ? 0 : 1);
      if (is_get) {
        depth = size - inputs;
      } else {
        inputs += size;        // putxxx pops the value from the stack
        depth = - inputs;
      }
    }
    break;

  case Bytecodes::_invokevirtual:
  case Bytecodes::_invokespecial:
  case Bytecodes::_invokestatic:
  case Bytecodes::_invokedynamic:
  case Bytecodes::_invokeinterface:
    {
      bool ignore;
      ciBytecodeStream iter(method());
      iter.reset_to_bci(bci());
      iter.next();
      ciMethod* method = iter.get_method(ignore);
      inputs = method->arg_size_no_receiver();
      // Add a receiver argument, maybe:
      if (code != Bytecodes::_invokestatic &&
          code != Bytecodes::_invokedynamic)
        inputs += 1;
      // (Do not use ciMethod::arg_size(), because
      // it might be an unloaded method, which doesn't
      // know whether it is static or not.)
      int size = method->return_type()->size();
      depth = size - inputs;
    }
    break;

  case Bytecodes::_multianewarray:
    {
      ciBytecodeStream iter(method());
      iter.reset_to_bci(bci());
      iter.next();
      inputs = iter.get_dimensions();
      assert(rsize == 1, "");
      depth = rsize - inputs;
    }
    break;

  case Bytecodes::_ireturn:
  case Bytecodes::_lreturn:
  case Bytecodes::_freturn:
  case Bytecodes::_dreturn:
  case Bytecodes::_areturn:
    assert(rsize = -depth, "");
    inputs = rsize;
    break;

  case Bytecodes::_jsr:
  case Bytecodes::_jsr_w:
    inputs = 0;
    depth  = 1;                  // S.B. depth=1, not zero
    break;

  default:
    // bytecode produces a typed result
    inputs = rsize - depth;
    assert(inputs >= 0, "");
    break;
  }

#ifdef ASSERT
  // spot check
  int outputs = depth + inputs;
  assert(outputs >= 0, "sanity");
  switch (code) {
  case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
  case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
  case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
  case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
  case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
  }
#endif //ASSERT

  return true;
}



//------------------------------basic_plus_adr---------------------------------
Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
  // short-circuit a common case
  if (offset == intcon(0))  return ptr;
  return _gvn.transform( new (C, 4) AddPNode(base, ptr, offset) );
}

Node* GraphKit::ConvI2L(Node* offset) {
  // short-circuit a common case
  jint offset_con = find_int_con(offset, Type::OffsetBot);
  if (offset_con != Type::OffsetBot) {
    return longcon((long) offset_con);
  }
  return _gvn.transform( new (C, 2) ConvI2LNode(offset));
}
Node* GraphKit::ConvL2I(Node* offset) {
  // short-circuit a common case
  jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
  if (offset_con != (jlong)Type::OffsetBot) {
    return intcon((int) offset_con);
  }
  return _gvn.transform( new (C, 2) ConvL2INode(offset));
}

//-------------------------load_object_klass-----------------------------------
Node* GraphKit::load_object_klass(Node* obj) {
  // Special-case a fresh allocation to avoid building nodes:
  Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
  if (akls != NULL)  return akls;
  Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
  return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) );
}

//-------------------------load_array_length-----------------------------------
Node* GraphKit::load_array_length(Node* array) {
  // Special-case a fresh allocation to avoid building nodes:
  AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
  Node *alen;
  if (alloc == NULL) {
    Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
    alen = _gvn.transform( new (C, 3) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
  } else {
    alen = alloc->Ideal_length();
    Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
    if (ccast != alen) {
      alen = _gvn.transform(ccast);
    }
  }
  return alen;
}

//------------------------------do_null_check----------------------------------
// Helper function to do a NULL pointer check.  Returned value is
// the incoming address with NULL casted away.  You are allowed to use the
// not-null value only if you are control dependent on the test.
extern int explicit_null_checks_inserted,
           explicit_null_checks_elided;
Node* GraphKit::null_check_common(Node* value, BasicType type,
                                  // optional arguments for variations:
                                  bool assert_null,
                                  Node* *null_control) {
  assert(!assert_null || null_control == NULL, "not both at once");
  if (stopped())  return top();
  if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
    // For some performance testing, we may wish to suppress null checking.
    value = cast_not_null(value);   // Make it appear to be non-null (4962416).
    return value;
  }
  explicit_null_checks_inserted++;

  // Construct NULL check
  Node *chk = NULL;
  switch(type) {
    case T_LONG   : chk = new (C, 3) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
    case T_INT    : chk = new (C, 3) CmpINode( value, _gvn.intcon(0)); break;
    case T_ARRAY  : // fall through
      type = T_OBJECT;  // simplify further tests
    case T_OBJECT : {
      const Type *t = _gvn.type( value );

      const TypeOopPtr* tp = t->isa_oopptr();
      if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
          // Only for do_null_check, not any of its siblings:
          && !assert_null && null_control == NULL) {
        // Usually, any field access or invocation on an unloaded oop type
        // will simply fail to link, since the statically linked class is
        // likely also to be unloaded.  However, in -Xcomp mode, sometimes
        // the static class is loaded but the sharper oop type is not.
        // Rather than checking for this obscure case in lots of places,
        // we simply observe that a null check on an unloaded class
        // will always be followed by a nonsense operation, so we
        // can just issue the uncommon trap here.
        // Our access to the unloaded class will only be correct
        // after it has been loaded and initialized, which requires
        // a trip through the interpreter.
#ifndef PRODUCT
        if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
#endif
        uncommon_trap(Deoptimization::Reason_unloaded,
                      Deoptimization::Action_reinterpret,
                      tp->klass(), "!loaded");
        return top();
      }

      if (assert_null) {
        // See if the type is contained in NULL_PTR.
        // If so, then the value is already null.
        if (t->higher_equal(TypePtr::NULL_PTR)) {
          explicit_null_checks_elided++;
          return value;           // Elided null assert quickly!
        }
      } else {
        // See if mixing in the NULL pointer changes type.
        // If so, then the NULL pointer was not allowed in the original
        // type.  In other words, "value" was not-null.
        if (t->meet(TypePtr::NULL_PTR) != t) {
          // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
          explicit_null_checks_elided++;
          return value;           // Elided null check quickly!
        }
      }
      chk = new (C, 3) CmpPNode( value, null() );
      break;
    }

    default      : ShouldNotReachHere();
  }
  assert(chk != NULL, "sanity check");
  chk = _gvn.transform(chk);

  BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
  BoolNode *btst = new (C, 2) BoolNode( chk, btest);
  Node   *tst = _gvn.transform( btst );

  //-----------
  // if peephole optimizations occurred, a prior test existed.
  // If a prior test existed, maybe it dominates as we can avoid this test.
  if (tst != btst && type == T_OBJECT) {
    // At this point we want to scan up the CFG to see if we can
    // find an identical test (and so avoid this test altogether).
    Node *cfg = control();
    int depth = 0;
    while( depth < 16 ) {       // Limit search depth for speed
      if( cfg->Opcode() == Op_IfTrue &&
          cfg->in(0)->in(1) == tst ) {
        // Found prior test.  Use "cast_not_null" to construct an identical
        // CastPP (and hence hash to) as already exists for the prior test.
        // Return that casted value.
        if (assert_null) {
          replace_in_map(value, null());
          return null();  // do not issue the redundant test
        }
        Node *oldcontrol = control();
        set_control(cfg);
        Node *res = cast_not_null(value);
        set_control(oldcontrol);
        explicit_null_checks_elided++;
        return res;
      }
      cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
      if (cfg == NULL)  break;  // Quit at region nodes
      depth++;
    }
  }

  //-----------
  // Branch to failure if null
  float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
  Deoptimization::DeoptReason reason;
  if (assert_null)
    reason = Deoptimization::Reason_null_assert;
  else if (type == T_OBJECT)
    reason = Deoptimization::Reason_null_check;
  else
    reason = Deoptimization::Reason_div0_check;

  // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
  // ciMethodData::has_trap_at will return a conservative -1 if any
  // must-be-null assertion has failed.  This could cause performance
  // problems for a method after its first do_null_assert failure.
  // Consider using 'Reason_class_check' instead?

  // To cause an implicit null check, we set the not-null probability
  // to the maximum (PROB_MAX).  For an explicit check the probability
  // is set to a smaller value.
  if (null_control != NULL || too_many_traps(reason)) {
    // probability is less likely
    ok_prob =  PROB_LIKELY_MAG(3);
  } else if (!assert_null &&
             (ImplicitNullCheckThreshold > 0) &&
             method() != NULL &&
             (method()->method_data()->trap_count(reason)
              >= (uint)ImplicitNullCheckThreshold)) {
    ok_prob =  PROB_LIKELY_MAG(3);
  }

  if (null_control != NULL) {
    IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
    Node* null_true = _gvn.transform( new (C, 1) IfFalseNode(iff));
    set_control(      _gvn.transform( new (C, 1) IfTrueNode(iff)));
    if (null_true == top())
      explicit_null_checks_elided++;
    (*null_control) = null_true;
  } else {
    BuildCutout unless(this, tst, ok_prob);
    // Check for optimizer eliding test at parse time
    if (stopped()) {
      // Failure not possible; do not bother making uncommon trap.
      explicit_null_checks_elided++;
    } else if (assert_null) {
      uncommon_trap(reason,
                    Deoptimization::Action_make_not_entrant,
                    NULL, "assert_null");
    } else {
      replace_in_map(value, zerocon(type));
      builtin_throw(reason);
    }
  }

  // Must throw exception, fall-thru not possible?
  if (stopped()) {
    return top();               // No result
  }

  if (assert_null) {
    // Cast obj to null on this path.
    replace_in_map(value, zerocon(type));
    return zerocon(type);
  }

  // Cast obj to not-null on this path, if there is no null_control.
  // (If there is a null_control, a non-null value may come back to haunt us.)
  if (type == T_OBJECT) {
    Node* cast = cast_not_null(value, false);
    if (null_control == NULL || (*null_control) == top())
      replace_in_map(value, cast);
    value = cast;
  }

  return value;
}


//------------------------------cast_not_null----------------------------------
// Cast obj to not-null on this path
Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
  const Type *t = _gvn.type(obj);
  const Type *t_not_null = t->join(TypePtr::NOTNULL);
  // Object is already not-null?
  if( t == t_not_null ) return obj;

  Node *cast = new (C, 2) CastPPNode(obj,t_not_null);
  cast->init_req(0, control());
  cast = _gvn.transform( cast );

  // Scan for instances of 'obj' in the current JVM mapping.
  // These instances are known to be not-null after the test.
  if (do_replace_in_map)
    replace_in_map(obj, cast);

  return cast;                  // Return casted value
}


//--------------------------replace_in_map-------------------------------------
void GraphKit::replace_in_map(Node* old, Node* neww) {
  this->map()->replace_edge(old, neww);

  // Note: This operation potentially replaces any edge
  // on the map.  This includes locals, stack, and monitors
  // of the current (innermost) JVM state.

  // We can consider replacing in caller maps.
  // The idea would be that an inlined function's null checks
  // can be shared with the entire inlining tree.
  // The expense of doing this is that the PreserveJVMState class
  // would have to preserve caller states too, with a deep copy.
}



//=============================================================================
//--------------------------------memory---------------------------------------
Node* GraphKit::memory(uint alias_idx) {
  MergeMemNode* mem = merged_memory();
  Node* p = mem->memory_at(alias_idx);
  _gvn.set_type(p, Type::MEMORY);  // must be mapped
  return p;
}

//-----------------------------reset_memory------------------------------------
Node* GraphKit::reset_memory() {
  Node* mem = map()->memory();
  // do not use this node for any more parsing!
  debug_only( map()->set_memory((Node*)NULL) );
  return _gvn.transform( mem );
}

//------------------------------set_all_memory---------------------------------
void GraphKit::set_all_memory(Node* newmem) {
  Node* mergemem = MergeMemNode::make(C, newmem);
  gvn().set_type_bottom(mergemem);
  map()->set_memory(mergemem);
}

//------------------------------set_all_memory_call----------------------------
void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
  Node* newmem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory, separate_io_proj) );
  set_all_memory(newmem);
}

//=============================================================================
//
// parser factory methods for MemNodes
//
// These are layered on top of the factory methods in LoadNode and StoreNode,
// and integrate with the parser's memory state and _gvn engine.
//

// factory methods in "int adr_idx"
Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
                          int adr_idx,
                          bool require_atomic_access) {
  assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
  const TypePtr* adr_type = NULL; // debug-mode-only argument
  debug_only(adr_type = C->get_adr_type(adr_idx));
  Node* mem = memory(adr_idx);
  Node* ld;
  if (require_atomic_access && bt == T_LONG) {
    ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t);
  } else {
    ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt);
  }
  return _gvn.transform(ld);
}

Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
                                int adr_idx,
                                bool require_atomic_access) {
  assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
  const TypePtr* adr_type = NULL;
  debug_only(adr_type = C->get_adr_type(adr_idx));
  Node *mem = memory(adr_idx);
  Node* st;
  if (require_atomic_access && bt == T_LONG) {
    st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val);
  } else {
    st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt);
  }
  st = _gvn.transform(st);
  set_memory(st, adr_idx);
  // Back-to-back stores can only remove intermediate store with DU info
  // so push on worklist for optimizer.
  if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
    record_for_igvn(st);

  return st;
}


void GraphKit::pre_barrier(bool do_load,
                           Node* ctl,
                           Node* obj,
                           Node* adr,
                           uint  adr_idx,
                           Node* val,
                           const TypeOopPtr* val_type,
                           Node* pre_val,
                           BasicType bt) {

  BarrierSet* bs = Universe::heap()->barrier_set();
  set_control(ctl);
  switch (bs->kind()) {
    case BarrierSet::G1SATBCT:
    case BarrierSet::G1SATBCTLogging:
      g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
      break;

    case BarrierSet::CardTableModRef:
    case BarrierSet::CardTableExtension:
    case BarrierSet::ModRef:
      break;

    case BarrierSet::Other:
    default      :
      ShouldNotReachHere();

  }
}

void GraphKit::post_barrier(Node* ctl,
                            Node* store,
                            Node* obj,
                            Node* adr,
                            uint  adr_idx,
                            Node* val,
                            BasicType bt,
                            bool use_precise) {
  BarrierSet* bs = Universe::heap()->barrier_set();
  set_control(ctl);
  switch (bs->kind()) {
    case BarrierSet::G1SATBCT:
    case BarrierSet::G1SATBCTLogging:
      g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
      break;

    case BarrierSet::CardTableModRef:
    case BarrierSet::CardTableExtension:
      write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
      break;

    case BarrierSet::ModRef:
      break;

    case BarrierSet::Other:
    default      :
      ShouldNotReachHere();

  }
}

Node* GraphKit::store_oop(Node* ctl,
                          Node* obj,
                          Node* adr,
                          const TypePtr* adr_type,
                          Node* val,
                          const TypeOopPtr* val_type,
                          BasicType bt,
                          bool use_precise) {

  set_control(ctl);
  if (stopped()) return top(); // Dead path ?

  assert(bt == T_OBJECT, "sanity");
  assert(val != NULL, "not dead path");
  uint adr_idx = C->get_alias_index(adr_type);
  assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );

  pre_barrier(true /* do_load */,
              control(), obj, adr, adr_idx, val, val_type,
              NULL /* pre_val */,
              bt);

  Node* store = store_to_memory(control(), adr, val, bt, adr_idx);
  post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
  return store;
}

// Could be an array or object we don't know at compile time (unsafe ref.)
Node* GraphKit::store_oop_to_unknown(Node* ctl,
                             Node* obj,   // containing obj
                             Node* adr,  // actual adress to store val at
                             const TypePtr* adr_type,
                             Node* val,
                             BasicType bt) {
  Compile::AliasType* at = C->alias_type(adr_type);
  const TypeOopPtr* val_type = NULL;
  if (adr_type->isa_instptr()) {
    if (at->field() != NULL) {
      // known field.  This code is a copy of the do_put_xxx logic.
      ciField* field = at->field();
      if (!field->type()->is_loaded()) {
        val_type = TypeInstPtr::BOTTOM;
      } else {
        val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
      }
    }
  } else if (adr_type->isa_aryptr()) {
    val_type = adr_type->is_aryptr()->elem()->make_oopptr();
  }
  if (val_type == NULL) {
    val_type = TypeInstPtr::BOTTOM;
  }
  return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true);
}


//-------------------------array_element_address-------------------------
Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
                                      const TypeInt* sizetype) {
  uint shift  = exact_log2(type2aelembytes(elembt));
  uint header = arrayOopDesc::base_offset_in_bytes(elembt);

  // short-circuit a common case (saves lots of confusing waste motion)
  jint idx_con = find_int_con(idx, -1);
  if (idx_con >= 0) {
    intptr_t offset = header + ((intptr_t)idx_con << shift);
    return basic_plus_adr(ary, offset);
  }

  // must be correct type for alignment purposes
  Node* base  = basic_plus_adr(ary, header);
#ifdef _LP64
  // The scaled index operand to AddP must be a clean 64-bit value.
  // Java allows a 32-bit int to be incremented to a negative
  // value, which appears in a 64-bit register as a large
  // positive number.  Using that large positive number as an
  // operand in pointer arithmetic has bad consequences.
  // On the other hand, 32-bit overflow is rare, and the possibility
  // can often be excluded, if we annotate the ConvI2L node with
  // a type assertion that its value is known to be a small positive
  // number.  (The prior range check has ensured this.)
  // This assertion is used by ConvI2LNode::Ideal.
  int index_max = max_jint - 1;  // array size is max_jint, index is one less
  if (sizetype != NULL)  index_max = sizetype->_hi - 1;
  const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
  idx = _gvn.transform( new (C, 2) ConvI2LNode(idx, lidxtype) );
#endif
  Node* scale = _gvn.transform( new (C, 3) LShiftXNode(idx, intcon(shift)) );
  return basic_plus_adr(ary, base, scale);
}

//-------------------------load_array_element-------------------------
Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
  const Type* elemtype = arytype->elem();
  BasicType elembt = elemtype->array_element_basic_type();
  Node* adr = array_element_address(ary, idx, elembt, arytype->size());
  Node* ld = make_load(ctl, adr, elemtype, elembt, arytype);
  return ld;
}

//-------------------------set_arguments_for_java_call-------------------------
// Arguments (pre-popped from the stack) are taken from the JVMS.
void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
  // Add the call arguments:
  uint nargs = call->method()->arg_size();
  for (uint i = 0; i < nargs; i++) {
    Node* arg = argument(i);
    call->init_req(i + TypeFunc::Parms, arg);
  }
}

//---------------------------set_edges_for_java_call---------------------------
// Connect a newly created call into the current JVMS.
// A return value node (if any) is returned from set_edges_for_java_call.
void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {

  // Add the predefined inputs:
  call->init_req( TypeFunc::Control, control() );
  call->init_req( TypeFunc::I_O    , i_o() );
  call->init_req( TypeFunc::Memory , reset_memory() );
  call->init_req( TypeFunc::FramePtr, frameptr() );
  call->init_req( TypeFunc::ReturnAdr, top() );

  add_safepoint_edges(call, must_throw);

  Node* xcall = _gvn.transform(call);

  if (xcall == top()) {
    set_control(top());
    return;
  }
  assert(xcall == call, "call identity is stable");

  // Re-use the current map to produce the result.

  set_control(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Control)));
  set_i_o(    _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
  set_all_memory_call(xcall, separate_io_proj);

  //return xcall;   // no need, caller already has it
}

Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
  if (stopped())  return top();  // maybe the call folded up?

  // Capture the return value, if any.
  Node* ret;
  if (call->method() == NULL ||
      call->method()->return_type()->basic_type() == T_VOID)
        ret = top();
  else  ret = _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Parms));

  // Note:  Since any out-of-line call can produce an exception,
  // we always insert an I_O projection from the call into the result.

  make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);

  if (separate_io_proj) {
    // The caller requested separate projections be used by the fall
    // through and exceptional paths, so replace the projections for
    // the fall through path.
    set_i_o(_gvn.transform( new (C, 1) ProjNode(call, TypeFunc::I_O) ));
    set_all_memory(_gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) ));
  }
  return ret;
}

//--------------------set_predefined_input_for_runtime_call--------------------
// Reading and setting the memory state is way conservative here.
// The real problem is that I am not doing real Type analysis on memory,
// so I cannot distinguish card mark stores from other stores.  Across a GC
// point the Store Barrier and the card mark memory has to agree.  I cannot
// have a card mark store and its barrier split across the GC point from
// either above or below.  Here I get that to happen by reading ALL of memory.
// A better answer would be to separate out card marks from other memory.
// For now, return the input memory state, so that it can be reused
// after the call, if this call has restricted memory effects.
Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
  // Set fixed predefined input arguments
  Node* memory = reset_memory();
  call->init_req( TypeFunc::Control,   control()  );
  call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
  call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
  call->init_req( TypeFunc::FramePtr,  frameptr() );
  call->init_req( TypeFunc::ReturnAdr, top()      );
  return memory;
}

//-------------------set_predefined_output_for_runtime_call--------------------
// Set control and memory (not i_o) from the call.
// If keep_mem is not NULL, use it for the output state,
// except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
// If hook_mem is NULL, this call produces no memory effects at all.
// If hook_mem is a Java-visible memory slice (such as arraycopy operands),
// then only that memory slice is taken from the call.
// In the last case, we must put an appropriate memory barrier before
// the call, so as to create the correct anti-dependencies on loads
// preceding the call.
void GraphKit::set_predefined_output_for_runtime_call(Node* call,
                                                      Node* keep_mem,
                                                      const TypePtr* hook_mem) {
  // no i/o
  set_control(_gvn.transform( new (C, 1) ProjNode(call,TypeFunc::Control) ));
  if (keep_mem) {
    // First clone the existing memory state
    set_all_memory(keep_mem);
    if (hook_mem != NULL) {
      // Make memory for the call
      Node* mem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) );
      // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
      // We also use hook_mem to extract specific effects from arraycopy stubs.
      set_memory(mem, hook_mem);
    }
    // ...else the call has NO memory effects.

    // Make sure the call advertises its memory effects precisely.
    // This lets us build accurate anti-dependences in gcm.cpp.
    assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
           "call node must be constructed correctly");
  } else {
    assert(hook_mem == NULL, "");
    // This is not a "slow path" call; all memory comes from the call.
    set_all_memory_call(call);
  }
}


// Replace the call with the current state of the kit.
void GraphKit::replace_call(CallNode* call, Node* result) {
  JVMState* ejvms = NULL;
  if (has_exceptions()) {
    ejvms = transfer_exceptions_into_jvms();
  }

  SafePointNode* final_state = stop();

  // Find all the needed outputs of this call
  CallProjections callprojs;
  call->extract_projections(&callprojs, true);

  // Replace all the old call edges with the edges from the inlining result
  C->gvn_replace_by(callprojs.fallthrough_catchproj, final_state->in(TypeFunc::Control));
  C->gvn_replace_by(callprojs.fallthrough_memproj,   final_state->in(TypeFunc::Memory));
  C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_state->in(TypeFunc::I_O));
  Node* final_mem = final_state->in(TypeFunc::Memory);

  // Replace the result with the new result if it exists and is used
  if (callprojs.resproj != NULL && result != NULL) {
    C->gvn_replace_by(callprojs.resproj, result);
  }

  if (ejvms == NULL) {
    // No exception edges to simply kill off those paths
    C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
    C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
    C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());

    // Replace the old exception object with top
    if (callprojs.exobj != NULL) {
      C->gvn_replace_by(callprojs.exobj, C->top());
    }
  } else {
    GraphKit ekit(ejvms);

    // Load my combined exception state into the kit, with all phis transformed:
    SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();

    Node* ex_oop = ekit.use_exception_state(ex_map);

    C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
    C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
    C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());

    // Replace the old exception object with the newly created one
    if (callprojs.exobj != NULL) {
      C->gvn_replace_by(callprojs.exobj, ex_oop);
    }
  }

  // Disconnect the call from the graph
  call->disconnect_inputs(NULL);
  C->gvn_replace_by(call, C->top());

  // Clean up any MergeMems that feed other MergeMems since the
  // optimizer doesn't like that.
  if (final_mem->is_MergeMem()) {
    Node_List wl;
    for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
      Node* m = i.get();
      if (m->is_MergeMem() && !wl.contains(m)) {
        wl.push(m);
      }
    }
    while (wl.size()  > 0) {
      _gvn.transform(wl.pop());
    }
  }
}


//------------------------------increment_counter------------------------------
// for statistics: increment a VM counter by 1

void GraphKit::increment_counter(address counter_addr) {
  Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
  increment_counter(adr1);
}

void GraphKit::increment_counter(Node* counter_addr) {
  int adr_type = Compile::AliasIdxRaw;
  Node* ctrl = control();
  Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type);
  Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1)));
  store_to_memory( ctrl, counter_addr, incr, T_INT, adr_type );
}


//------------------------------uncommon_trap----------------------------------
// Bail out to the interpreter in mid-method.  Implemented by calling the
// uncommon_trap blob.  This helper function inserts a runtime call with the
// right debug info.
void GraphKit::uncommon_trap(int trap_request,
                             ciKlass* klass, const char* comment,
                             bool must_throw,
                             bool keep_exact_action) {
  if (failing())  stop();
  if (stopped())  return; // trap reachable?

  // Note:  If ProfileTraps is true, and if a deopt. actually
  // occurs here, the runtime will make sure an MDO exists.  There is
  // no need to call method()->ensure_method_data() at this point.

#ifdef ASSERT
  if (!must_throw) {
    // Make sure the stack has at least enough depth to execute
    // the current bytecode.
    int inputs, ignore;
    if (compute_stack_effects(inputs, ignore)) {
      assert(sp() >= inputs, "must have enough JVMS stack to execute");
      // It is a frequent error in library_call.cpp to issue an
      // uncommon trap with the _sp value already popped.
    }
  }
#endif

  Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
  Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);

  switch (action) {
  case Deoptimization::Action_maybe_recompile:
  case Deoptimization::Action_reinterpret:
    // Temporary fix for 6529811 to allow virtual calls to be sure they
    // get the chance to go from mono->bi->mega
    if (!keep_exact_action &&
        Deoptimization::trap_request_index(trap_request) < 0 &&
        too_many_recompiles(reason)) {
      // This BCI is causing too many recompilations.
      action = Deoptimization::Action_none;
      trap_request = Deoptimization::make_trap_request(reason, action);
    } else {
      C->set_trap_can_recompile(true);
    }
    break;
  case Deoptimization::Action_make_not_entrant:
    C->set_trap_can_recompile(true);
    break;
#ifdef ASSERT
  case Deoptimization::Action_none:
  case Deoptimization::Action_make_not_compilable:
    break;
  default:
    assert(false, "bad action");
#endif
  }

  if (TraceOptoParse) {
    char buf[100];
    tty->print_cr("Uncommon trap %s at bci:%d",
                  Deoptimization::format_trap_request(buf, sizeof(buf),
                                                      trap_request), bci());
  }

  CompileLog* log = C->log();
  if (log != NULL) {
    int kid = (klass == NULL)? -1: log->identify(klass);
    log->begin_elem("uncommon_trap bci='%d'", bci());
    char buf[100];
    log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
                                                          trap_request));
    if (kid >= 0)         log->print(" klass='%d'", kid);
    if (comment != NULL)  log->print(" comment='%s'", comment);
    log->end_elem();
  }

  // Make sure any guarding test views this path as very unlikely
  Node *i0 = control()->in(0);
  if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
    IfNode *iff = i0->as_If();
    float f = iff->_prob;   // Get prob
    if (control()->Opcode() == Op_IfTrue) {
      if (f > PROB_UNLIKELY_MAG(4))
        iff->_prob = PROB_MIN;
    } else {
      if (f < PROB_LIKELY_MAG(4))
        iff->_prob = PROB_MAX;
    }
  }

  // Clear out dead values from the debug info.
  kill_dead_locals();

  // Now insert the uncommon trap subroutine call
  address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
  const TypePtr* no_memory_effects = NULL;
  // Pass the index of the class to be loaded
  Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
                                 (must_throw ? RC_MUST_THROW : 0),
                                 OptoRuntime::uncommon_trap_Type(),
                                 call_addr, "uncommon_trap", no_memory_effects,
                                 intcon(trap_request));
  assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
         "must extract request correctly from the graph");
  assert(trap_request != 0, "zero value reserved by uncommon_trap_request");

  call->set_req(TypeFunc::ReturnAdr, returnadr());
  // The debug info is the only real input to this call.

  // Halt-and-catch fire here.  The above call should never return!
  HaltNode* halt = new(C, TypeFunc::Parms) HaltNode(control(), frameptr());
  _gvn.set_type_bottom(halt);
  root()->add_req(halt);

  stop_and_kill_map();
}


//--------------------------just_allocated_object------------------------------
// Report the object that was just allocated.
// It must be the case that there are no intervening safepoints.
// We use this to determine if an object is so "fresh" that
// it does not require card marks.
Node* GraphKit::just_allocated_object(Node* current_control) {
  if (C->recent_alloc_ctl() == current_control)
    return C->recent_alloc_obj();
  return NULL;
}


void GraphKit::round_double_arguments(ciMethod* dest_method) {
  // (Note:  TypeFunc::make has a cache that makes this fast.)
  const TypeFunc* tf    = TypeFunc::make(dest_method);
  int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
  for (int j = 0; j < nargs; j++) {
    const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
    if( targ->basic_type() == T_DOUBLE ) {
      // If any parameters are doubles, they must be rounded before
      // the call, dstore_rounding does gvn.transform
      Node *arg = argument(j);
      arg = dstore_rounding(arg);
      set_argument(j, arg);
    }
  }
}

void GraphKit::round_double_result(ciMethod* dest_method) {
  // A non-strict method may return a double value which has an extended
  // exponent, but this must not be visible in a caller which is 'strict'
  // If a strict caller invokes a non-strict callee, round a double result

  BasicType result_type = dest_method->return_type()->basic_type();
  assert( method() != NULL, "must have caller context");
  if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
    // Destination method's return value is on top of stack
    // dstore_rounding() does gvn.transform
    Node *result = pop_pair();
    result = dstore_rounding(result);
    push_pair(result);
  }
}

// rounding for strict float precision conformance
Node* GraphKit::precision_rounding(Node* n) {
  return UseStrictFP && _method->flags().is_strict()
    && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
    ? _gvn.transform( new (C, 2) RoundFloatNode(0, n) )
    : n;
}

// rounding for strict double precision conformance
Node* GraphKit::dprecision_rounding(Node *n) {
  return UseStrictFP && _method->flags().is_strict()
    && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
    ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) )
    : n;
}

// rounding for non-strict double stores
Node* GraphKit::dstore_rounding(Node* n) {
  return Matcher::strict_fp_requires_explicit_rounding
    && UseSSE <= 1
    ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) )
    : n;
}

//=============================================================================
// Generate a fast path/slow path idiom.  Graph looks like:
// [foo] indicates that 'foo' is a parameter
//
//              [in]     NULL
//                 \    /
//                  CmpP
//                  Bool ne
//                   If
//                  /  \
//              True    False-<2>
//              / |
//             /  cast_not_null
//           Load  |    |   ^
//        [fast_test]   |   |
// gvn to   opt_test    |   |
//          /    \      |  <1>
//      True     False  |
//        |         \\  |
//   [slow_call]     \[fast_result]
//    Ctl   Val       \      \
//     |               \      \
//    Catch       <1>   \      \
//   /    \        ^     \      \
//  Ex    No_Ex    |      \      \
//  |       \   \  |       \ <2>  \
//  ...      \  [slow_res] |  |    \   [null_result]
//            \         \--+--+---  |  |
//             \           | /    \ | /
//              --------Region     Phi
//
//=============================================================================
// Code is structured as a series of driver functions all called 'do_XXX' that
// call a set of helper functions.  Helper functions first, then drivers.

//------------------------------null_check_oop---------------------------------
// Null check oop.  Set null-path control into Region in slot 3.
// Make a cast-not-nullness use the other not-null control.  Return cast.
Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
                               bool never_see_null) {
  // Initial NULL check taken path
  (*null_control) = top();
  Node* cast = null_check_common(value, T_OBJECT, false, null_control);

  // Generate uncommon_trap:
  if (never_see_null && (*null_control) != top()) {
    // If we see an unexpected null at a check-cast we record it and force a
    // recompile; the offending check-cast will be compiled to handle NULLs.
    // If we see more than one offending BCI, then all checkcasts in the
    // method will be compiled to handle NULLs.
    PreserveJVMState pjvms(this);
    set_control(*null_control);
    replace_in_map(value, null());
    uncommon_trap(Deoptimization::Reason_null_check,
                  Deoptimization::Action_make_not_entrant);
    (*null_control) = top();    // NULL path is dead
  }

  // Cast away null-ness on the result
  return cast;
}

//------------------------------opt_iff----------------------------------------
// Optimize the fast-check IfNode.  Set the fast-path region slot 2.
// Return slow-path control.
Node* GraphKit::opt_iff(Node* region, Node* iff) {
  IfNode *opt_iff = _gvn.transform(iff)->as_If();

  // Fast path taken; set region slot 2
  Node *fast_taken = _gvn.transform( new (C, 1) IfFalseNode(opt_iff) );
  region->init_req(2,fast_taken); // Capture fast-control

  // Fast path not-taken, i.e. slow path
  Node *slow_taken = _gvn.transform( new (C, 1) IfTrueNode(opt_iff) );
  return slow_taken;
}

//-----------------------------make_runtime_call-------------------------------
Node* GraphKit::make_runtime_call(int flags,
                                  const TypeFunc* call_type, address call_addr,
                                  const char* call_name,
                                  const TypePtr* adr_type,
                                  // The following parms are all optional.
                                  // The first NULL ends the list.
                                  Node* parm0, Node* parm1,
                                  Node* parm2, Node* parm3,
                                  Node* parm4, Node* parm5,
                                  Node* parm6, Node* parm7) {
  // Slow-path call
  int size = call_type->domain()->cnt();
  bool is_leaf = !(flags & RC_NO_LEAF);
  bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
  if (call_name == NULL) {
    assert(!is_leaf, "must supply name for leaf");
    call_name = OptoRuntime::stub_name(call_addr);
  }
  CallNode* call;
  if (!is_leaf) {
    call = new(C, size) CallStaticJavaNode(call_type, call_addr, call_name,
                                           bci(), adr_type);
  } else if (flags & RC_NO_FP) {
    call = new(C, size) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
  } else {
    call = new(C, size) CallLeafNode(call_type, call_addr, call_name, adr_type);
  }

  // The following is similar to set_edges_for_java_call,
  // except that the memory effects of the call are restricted to AliasIdxRaw.

  // Slow path call has no side-effects, uses few values
  bool wide_in  = !(flags & RC_NARROW_MEM);
  bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);

  Node* prev_mem = NULL;
  if (wide_in) {
    prev_mem = set_predefined_input_for_runtime_call(call);
  } else {
    assert(!wide_out, "narrow in => narrow out");
    Node* narrow_mem = memory(adr_type);
    prev_mem = reset_memory();
    map()->set_memory(narrow_mem);
    set_predefined_input_for_runtime_call(call);
  }

  // Hook each parm in order.  Stop looking at the first NULL.
  if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
  if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
  if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
  if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
  if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
  if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
  if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
  if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
    /* close each nested if ===> */  } } } } } } } }
  assert(call->in(call->req()-1) != NULL, "must initialize all parms");

  if (!is_leaf) {
    // Non-leaves can block and take safepoints:
    add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
  }
  // Non-leaves can throw exceptions:
  if (has_io) {
    call->set_req(TypeFunc::I_O, i_o());
  }

  if (flags & RC_UNCOMMON) {
    // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
    // (An "if" probability corresponds roughly to an unconditional count.
    // Sort of.)
    call->set_cnt(PROB_UNLIKELY_MAG(4));
  }

  Node* c = _gvn.transform(call);
  assert(c == call, "cannot disappear");

  if (wide_out) {
    // Slow path call has full side-effects.
    set_predefined_output_for_runtime_call(call);
  } else {
    // Slow path call has few side-effects, and/or sets few values.
    set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
  }

  if (has_io) {
    set_i_o(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O)));
  }
  return call;

}

//------------------------------merge_memory-----------------------------------
// Merge memory from one path into the current memory state.
void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
  for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
    Node* old_slice = mms.force_memory();
    Node* new_slice = mms.memory2();
    if (old_slice != new_slice) {
      PhiNode* phi;
      if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
        phi = new_slice->as_Phi();
        #ifdef ASSERT
        if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
          old_slice = old_slice->in(new_path);
        // Caller is responsible for ensuring that any pre-existing
        // phis are already aware of old memory.
        int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
        assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
        #endif
        mms.set_memory(phi);
      } else {
        phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
        _gvn.set_type(phi, Type::MEMORY);
        phi->set_req(new_path, new_slice);
        mms.set_memory(_gvn.transform(phi));  // assume it is complete
      }
    }
  }
}

//------------------------------make_slow_call_ex------------------------------
// Make the exception handler hookups for the slow call
void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
  if (stopped())  return;

  // Make a catch node with just two handlers:  fall-through and catch-all
  Node* i_o  = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
  Node* catc = _gvn.transform( new (C, 2) CatchNode(control(), i_o, 2) );
  Node* norm = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
  Node* excp = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );

  { PreserveJVMState pjvms(this);
    set_control(excp);
    set_i_o(i_o);

    if (excp != top()) {
      // Create an exception state also.
      // Use an exact type if the caller has specified a specific exception.
      const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
      Node*       ex_oop  = new (C, 2) CreateExNode(ex_type, control(), i_o);
      add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
    }
  }

  // Get the no-exception control from the CatchNode.
  set_control(norm);
}


//-------------------------------gen_subtype_check-----------------------------
// Generate a subtyping check.  Takes as input the subtype and supertype.
// Returns 2 values: sets the default control() to the true path and returns
// the false path.  Only reads invariant memory; sets no (visible) memory.
// The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
// but that's not exposed to the optimizer.  This call also doesn't take in an
// Object; if you wish to check an Object you need to load the Object's class
// prior to coming here.
Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
  // Fast check for identical types, perhaps identical constants.
  // The types can even be identical non-constants, in cases
  // involving Array.newInstance, Object.clone, etc.
  if (subklass == superklass)
    return top();             // false path is dead; no test needed.

  if (_gvn.type(superklass)->singleton()) {
    ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
    ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();

    // In the common case of an exact superklass, try to fold up the
    // test before generating code.  You may ask, why not just generate
    // the code and then let it fold up?  The answer is that the generated
    // code will necessarily include null checks, which do not always
    // completely fold away.  If they are also needless, then they turn
    // into a performance loss.  Example:
    //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
    // Here, the type of 'fa' is often exact, so the store check
    // of fa[1]=x will fold up, without testing the nullness of x.
    switch (static_subtype_check(superk, subk)) {
    case SSC_always_false:
      {
        Node* always_fail = control();
        set_control(top());
        return always_fail;
      }
    case SSC_always_true:
      return top();
    case SSC_easy_test:
      {
        // Just do a direct pointer compare and be done.
        Node* cmp = _gvn.transform( new(C, 3) CmpPNode(subklass, superklass) );
        Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) );
        IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
        set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) ) );
        return       _gvn.transform( new(C, 1) IfFalseNode(iff) );
      }
    case SSC_full_test:
      break;
    default:
      ShouldNotReachHere();
    }
  }

  // %%% Possible further optimization:  Even if the superklass is not exact,
  // if the subklass is the unique subtype of the superklass, the check
  // will always succeed.  We could leave a dependency behind to ensure this.

  // First load the super-klass's check-offset
  Node *p1 = basic_plus_adr( superklass, superklass, sizeof(oopDesc) + Klass::super_check_offset_offset_in_bytes() );
  Node *chk_off = _gvn.transform( new (C, 3) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) );
  int cacheoff_con = sizeof(oopDesc) + Klass::secondary_super_cache_offset_in_bytes();
  bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);

  // Load from the sub-klass's super-class display list, or a 1-word cache of
  // the secondary superclass list, or a failing value with a sentinel offset
  // if the super-klass is an interface or exceptionally deep in the Java
  // hierarchy and we have to scan the secondary superclass list the hard way.
  // Worst-case type is a little odd: NULL is allowed as a result (usually
  // klass loads can never produce a NULL).
  Node *chk_off_X = ConvI2X(chk_off);
  Node *p2 = _gvn.transform( new (C, 4) AddPNode(subklass,subklass,chk_off_X) );
  // For some types like interfaces the following loadKlass is from a 1-word
  // cache which is mutable so can't use immutable memory.  Other
  // types load from the super-class display table which is immutable.
  Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
  Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );

  // Compile speed common case: ARE a subtype and we canNOT fail
  if( superklass == nkls )
    return top();             // false path is dead; no test needed.

  // See if we get an immediate positive hit.  Happens roughly 83% of the
  // time.  Test to see if the value loaded just previously from the subklass
  // is exactly the superklass.
  Node *cmp1 = _gvn.transform( new (C, 3) CmpPNode( superklass, nkls ) );
  Node *bol1 = _gvn.transform( new (C, 2) BoolNode( cmp1, BoolTest::eq ) );
  IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
  Node *iftrue1 = _gvn.transform( new (C, 1) IfTrueNode ( iff1 ) );
  set_control(    _gvn.transform( new (C, 1) IfFalseNode( iff1 ) ) );

  // Compile speed common case: Check for being deterministic right now.  If
  // chk_off is a constant and not equal to cacheoff then we are NOT a
  // subklass.  In this case we need exactly the 1 test above and we can
  // return those results immediately.
  if (!might_be_cache) {
    Node* not_subtype_ctrl = control();
    set_control(iftrue1); // We need exactly the 1 test above
    return not_subtype_ctrl;
  }

  // Gather the various success & failures here
  RegionNode *r_ok_subtype = new (C, 4) RegionNode(4);
  record_for_igvn(r_ok_subtype);
  RegionNode *r_not_subtype = new (C, 3) RegionNode(3);
  record_for_igvn(r_not_subtype);

  r_ok_subtype->init_req(1, iftrue1);

  // Check for immediate negative hit.  Happens roughly 11% of the time (which
  // is roughly 63% of the remaining cases).  Test to see if the loaded
  // check-offset points into the subklass display list or the 1-element
  // cache.  If it points to the display (and NOT the cache) and the display
  // missed then it's not a subtype.
  Node *cacheoff = _gvn.intcon(cacheoff_con);
  Node *cmp2 = _gvn.transform( new (C, 3) CmpINode( chk_off, cacheoff ) );
  Node *bol2 = _gvn.transform( new (C, 2) BoolNode( cmp2, BoolTest::ne ) );
  IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
  r_not_subtype->init_req(1, _gvn.transform( new (C, 1) IfTrueNode (iff2) ) );
  set_control(                _gvn.transform( new (C, 1) IfFalseNode(iff2) ) );

  // Check for self.  Very rare to get here, but it is taken 1/3 the time.
  // No performance impact (too rare) but allows sharing of secondary arrays
  // which has some footprint reduction.
  Node *cmp3 = _gvn.transform( new (C, 3) CmpPNode( subklass, superklass ) );
  Node *bol3 = _gvn.transform( new (C, 2) BoolNode( cmp3, BoolTest::eq ) );
  IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
  r_ok_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode ( iff3 ) ) );
  set_control(               _gvn.transform( new (C, 1) IfFalseNode( iff3 ) ) );

  // -- Roads not taken here: --
  // We could also have chosen to perform the self-check at the beginning
  // of this code sequence, as the assembler does.  This would not pay off
  // the same way, since the optimizer, unlike the assembler, can perform
  // static type analysis to fold away many successful self-checks.
  // Non-foldable self checks work better here in second position, because
  // the initial primary superclass check subsumes a self-check for most
  // types.  An exception would be a secondary type like array-of-interface,
  // which does not appear in its own primary supertype display.
  // Finally, we could have chosen to move the self-check into the
  // PartialSubtypeCheckNode, and from there out-of-line in a platform
  // dependent manner.  But it is worthwhile to have the check here,
  // where it can be perhaps be optimized.  The cost in code space is
  // small (register compare, branch).

  // Now do a linear scan of the secondary super-klass array.  Again, no real
  // performance impact (too rare) but it's gotta be done.
  // Since the code is rarely used, there is no penalty for moving it
  // out of line, and it can only improve I-cache density.
  // The decision to inline or out-of-line this final check is platform
  // dependent, and is found in the AD file definition of PartialSubtypeCheck.
  Node* psc = _gvn.transform(
    new (C, 3) PartialSubtypeCheckNode(control(), subklass, superklass) );

  Node *cmp4 = _gvn.transform( new (C, 3) CmpPNode( psc, null() ) );
  Node *bol4 = _gvn.transform( new (C, 2) BoolNode( cmp4, BoolTest::ne ) );
  IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
  r_not_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode (iff4) ) );
  r_ok_subtype ->init_req(3, _gvn.transform( new (C, 1) IfFalseNode(iff4) ) );

  // Return false path; set default control to true path.
  set_control( _gvn.transform(r_ok_subtype) );
  return _gvn.transform(r_not_subtype);
}

//----------------------------static_subtype_check-----------------------------
// Shortcut important common cases when superklass is exact:
// (0) superklass is java.lang.Object (can occur in reflective code)
// (1) subklass is already limited to a subtype of superklass => always ok
// (2) subklass does not overlap with superklass => always fail
// (3) superklass has NO subtypes and we can check with a simple compare.
int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
  if (StressReflectiveCode) {
    return SSC_full_test;       // Let caller generate the general case.
  }

  if (superk == env()->Object_klass()) {
    return SSC_always_true;     // (0) this test cannot fail
  }

  ciType* superelem = superk;
  if (superelem->is_array_klass())
    superelem = superelem->as_array_klass()->base_element_type();

  if (!subk->is_interface()) {  // cannot trust static interface types yet
    if (subk->is_subtype_of(superk)) {
      return SSC_always_true;   // (1) false path dead; no dynamic test needed
    }
    if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
        !superk->is_subtype_of(subk)) {
      return SSC_always_false;
    }
  }

  // If casting to an instance klass, it must have no subtypes
  if (superk->is_interface()) {
    // Cannot trust interfaces yet.
    // %%% S.B. superk->nof_implementors() == 1
  } else if (superelem->is_instance_klass()) {
    ciInstanceKlass* ik = superelem->as_instance_klass();
    if (!ik->has_subklass() && !ik->is_interface()) {
      if (!ik->is_final()) {
        // Add a dependency if there is a chance of a later subclass.
        C->dependencies()->assert_leaf_type(ik);
      }
      return SSC_easy_test;     // (3) caller can do a simple ptr comparison
    }
  } else {
    // A primitive array type has no subtypes.
    return SSC_easy_test;       // (3) caller can do a simple ptr comparison
  }

  return SSC_full_test;
}

// Profile-driven exact type check:
Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
                                    float prob,
                                    Node* *casted_receiver) {
  const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
  Node* recv_klass = load_object_klass(receiver);
  Node* want_klass = makecon(tklass);
  Node* cmp = _gvn.transform( new(C, 3) CmpPNode(recv_klass, want_klass) );
  Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) );
  IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
  set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) ));
  Node* fail = _gvn.transform( new(C, 1) IfFalseNode(iff) );

  const TypeOopPtr* recv_xtype = tklass->as_instance_type();
  assert(recv_xtype->klass_is_exact(), "");

  // Subsume downstream occurrences of receiver with a cast to
  // recv_xtype, since now we know what the type will be.
  Node* cast = new(C, 2) CheckCastPPNode(control(), receiver, recv_xtype);
  (*casted_receiver) = _gvn.transform(cast);
  // (User must make the replace_in_map call.)

  return fail;
}


//------------------------------seems_never_null-------------------------------
// Use null_seen information if it is available from the profile.
// If we see an unexpected null at a type check we record it and force a
// recompile; the offending check will be recompiled to handle NULLs.
// If we see several offending BCIs, then all checks in the
// method will be recompiled.
bool GraphKit::seems_never_null(Node* obj, ciProfileData* data) {
  if (UncommonNullCast               // Cutout for this technique
      && obj != null()               // And not the -Xcomp stupid case?
      && !too_many_traps(Deoptimization::Reason_null_check)
      ) {
    if (data == NULL)
      // Edge case:  no mature data.  Be optimistic here.
      return true;
    // If the profile has not seen a null, assume it won't happen.
    assert(java_bc() == Bytecodes::_checkcast ||
           java_bc() == Bytecodes::_instanceof ||
           java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
    return !data->as_BitData()->null_seen();
  }
  return false;
}

//------------------------maybe_cast_profiled_receiver-------------------------
// If the profile has seen exactly one type, narrow to exactly that type.
// Subsequent type checks will always fold up.
Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
                                             ciProfileData* data,
                                             ciKlass* require_klass) {
  if (!UseTypeProfile || !TypeProfileCasts) return NULL;
  if (data == NULL)  return NULL;

  // Make sure we haven't already deoptimized from this tactic.
  if (too_many_traps(Deoptimization::Reason_class_check))
    return NULL;

  // (No, this isn't a call, but it's enough like a virtual call
  // to use the same ciMethod accessor to get the profile info...)
  ciCallProfile profile = method()->call_profile_at_bci(bci());
  if (profile.count() >= 0 &&         // no cast failures here
      profile.has_receiver(0) &&
      profile.morphism() == 1) {
    ciKlass* exact_kls = profile.receiver(0);
    if (require_klass == NULL ||
        static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
      // If we narrow the type to match what the type profile sees,
      // we can then remove the rest of the cast.
      // This is a win, even if the exact_kls is very specific,
      // because downstream operations, such as method calls,
      // will often benefit from the sharper type.
      Node* exact_obj = not_null_obj; // will get updated in place...
      Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
                                            &exact_obj);
      { PreserveJVMState pjvms(this);
        set_control(slow_ctl);
        uncommon_trap(Deoptimization::Reason_class_check,
                      Deoptimization::Action_maybe_recompile);
      }
      replace_in_map(not_null_obj, exact_obj);
      return exact_obj;
    }
    // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
  }

  return NULL;
}


//-------------------------------gen_instanceof--------------------------------
// Generate an instance-of idiom.  Used by both the instance-of bytecode
// and the reflective instance-of call.
Node* GraphKit::gen_instanceof(Node* obj, Node* superklass) {
  kill_dead_locals();           // Benefit all the uncommon traps
  assert( !stopped(), "dead parse path should be checked in callers" );
  assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
         "must check for not-null not-dead klass in callers");

  // Make the merge point
  enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
  RegionNode* region = new(C, PATH_LIMIT) RegionNode(PATH_LIMIT);
  Node*       phi    = new(C, PATH_LIMIT) PhiNode(region, TypeInt::BOOL);
  C->set_has_split_ifs(true); // Has chance for split-if optimization

  ciProfileData* data = NULL;
  if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
    data = method()->method_data()->bci_to_data(bci());
  }
  bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
                         && seems_never_null(obj, data));

  // Null check; get casted pointer; set region slot 3
  Node* null_ctl = top();
  Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);

  // If not_null_obj is dead, only null-path is taken
  if (stopped()) {              // Doing instance-of on a NULL?
    set_control(null_ctl);
    return intcon(0);
  }
  region->init_req(_null_path, null_ctl);
  phi   ->init_req(_null_path, intcon(0)); // Set null path value
  if (null_ctl == top()) {
    // Do this eagerly, so that pattern matches like is_diamond_phi
    // will work even during parsing.
    assert(_null_path == PATH_LIMIT-1, "delete last");
    region->del_req(_null_path);
    phi   ->del_req(_null_path);
  }

  if (ProfileDynamicTypes && data != NULL) {
    Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, NULL);
    if (stopped()) {            // Profile disagrees with this path.
      set_control(null_ctl);    // Null is the only remaining possibility.
      return intcon(0);
    }
    if (cast_obj != NULL)
      not_null_obj = cast_obj;
  }

  // Load the object's klass
  Node* obj_klass = load_object_klass(not_null_obj);

  // Generate the subtype check
  Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);

  // Plug in the success path to the general merge in slot 1.
  region->init_req(_obj_path, control());
  phi   ->init_req(_obj_path, intcon(1));

  // Plug in the failing path to the general merge in slot 2.
  region->init_req(_fail_path, not_subtype_ctrl);
  phi   ->init_req(_fail_path, intcon(0));

  // Return final merged results
  set_control( _gvn.transform(region) );
  record_for_igvn(region);
  return _gvn.transform(phi);
}

//-------------------------------gen_checkcast---------------------------------
// Generate a checkcast idiom.  Used by both the checkcast bytecode and the
// array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
// uncommon-trap paths work.  Adjust stack after this call.
// If failure_control is supplied and not null, it is filled in with
// the control edge for the cast failure.  Otherwise, an appropriate
// uncommon trap or exception is thrown.
Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
                              Node* *failure_control) {
  kill_dead_locals();           // Benefit all the uncommon traps
  const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
  const Type *toop = TypeOopPtr::make_from_klass(tk->klass());

  // Fast cutout:  Check the case that the cast is vacuously true.
  // This detects the common cases where the test will short-circuit
  // away completely.  We do this before we perform the null check,
  // because if the test is going to turn into zero code, we don't
  // want a residual null check left around.  (Causes a slowdown,
  // for example, in some objArray manipulations, such as a[i]=a[j].)
  if (tk->singleton()) {
    const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
    if (objtp != NULL && objtp->klass() != NULL) {
      switch (static_subtype_check(tk->klass(), objtp->klass())) {
      case SSC_always_true:
        return obj;
      case SSC_always_false:
        // It needs a null check because a null will *pass* the cast check.
        // A non-null value will always produce an exception.
        return do_null_assert(obj, T_OBJECT);
      }
    }
  }

  ciProfileData* data = NULL;
  if (failure_control == NULL) {        // use MDO in regular case only
    assert(java_bc() == Bytecodes::_aastore ||
           java_bc() == Bytecodes::_checkcast,
           "interpreter profiles type checks only for these BCs");
    data = method()->method_data()->bci_to_data(bci());
  }

  // Make the merge point
  enum { _obj_path = 1, _null_path, PATH_LIMIT };
  RegionNode* region = new (C, PATH_LIMIT) RegionNode(PATH_LIMIT);
  Node*       phi    = new (C, PATH_LIMIT) PhiNode(region, toop);
  C->set_has_split_ifs(true); // Has chance for split-if optimization

  // Use null-cast information if it is available
  bool never_see_null = ((failure_control == NULL)  // regular case only
                         && seems_never_null(obj, data));

  // Null check; get casted pointer; set region slot 3
  Node* null_ctl = top();
  Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null);

  // If not_null_obj is dead, only null-path is taken
  if (stopped()) {              // Doing instance-of on a NULL?
    set_control(null_ctl);
    return null();
  }
  region->init_req(_null_path, null_ctl);
  phi   ->init_req(_null_path, null());  // Set null path value
  if (null_ctl == top()) {
    // Do this eagerly, so that pattern matches like is_diamond_phi
    // will work even during parsing.
    assert(_null_path == PATH_LIMIT-1, "delete last");
    region->del_req(_null_path);
    phi   ->del_req(_null_path);
  }

  Node* cast_obj = NULL;
  if (data != NULL &&
      // Counter has never been decremented (due to cast failure).
      // ...This is a reasonable thing to expect.  It is true of
      // all casts inserted by javac to implement generic types.
      data->as_CounterData()->count() >= 0) {
    cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, tk->klass());
    if (cast_obj != NULL) {
      if (failure_control != NULL) // failure is now impossible
        (*failure_control) = top();
      // adjust the type of the phi to the exact klass:
      phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR));
    }
  }

  if (cast_obj == NULL) {
    // Load the object's klass
    Node* obj_klass = load_object_klass(not_null_obj);

    // Generate the subtype check
    Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );

    // Plug in success path into the merge
    cast_obj = _gvn.transform(new (C, 2) CheckCastPPNode(control(),
                                                         not_null_obj, toop));
    // Failure path ends in uncommon trap (or may be dead - failure impossible)
    if (failure_control == NULL) {
      if (not_subtype_ctrl != top()) { // If failure is possible
        PreserveJVMState pjvms(this);
        set_control(not_subtype_ctrl);
        builtin_throw(Deoptimization::Reason_class_check, obj_klass);
      }
    } else {
      (*failure_control) = not_subtype_ctrl;
    }
  }

  region->init_req(_obj_path, control());
  phi   ->init_req(_obj_path, cast_obj);

  // A merge of NULL or Casted-NotNull obj
  Node* res = _gvn.transform(phi);

  // Note I do NOT always 'replace_in_map(obj,result)' here.
  //  if( tk->klass()->can_be_primary_super()  )
    // This means that if I successfully store an Object into an array-of-String
    // I 'forget' that the Object is really now known to be a String.  I have to
    // do this because we don't have true union types for interfaces - if I store
    // a Baz into an array-of-Interface and then tell the optimizer it's an
    // Interface, I forget that it's also a Baz and cannot do Baz-like field
    // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
  //  replace_in_map( obj, res );

  // Return final merged results
  set_control( _gvn.transform(region) );
  record_for_igvn(region);
  return res;
}

//------------------------------next_monitor-----------------------------------
// What number should be given to the next monitor?
int GraphKit::next_monitor() {
  int current = jvms()->monitor_depth()* C->sync_stack_slots();
  int next = current + C->sync_stack_slots();
  // Keep the toplevel high water mark current:
  if (C->fixed_slots() < next)  C->set_fixed_slots(next);
  return current;
}

//------------------------------insert_mem_bar---------------------------------
// Memory barrier to avoid floating things around
// The membar serves as a pinch point between both control and all memory slices.
Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
  MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
  mb->init_req(TypeFunc::Control, control());
  mb->init_req(TypeFunc::Memory,  reset_memory());
  Node* membar = _gvn.transform(mb);
  set_control(_gvn.transform(new (C, 1) ProjNode(membar,TypeFunc::Control) ));
  set_all_memory_call(membar);
  return membar;
}

//-------------------------insert_mem_bar_volatile----------------------------
// Memory barrier to avoid floating things around
// The membar serves as a pinch point between both control and memory(alias_idx).
// If you want to make a pinch point on all memory slices, do not use this
// function (even with AliasIdxBot); use insert_mem_bar() instead.
Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
  // When Parse::do_put_xxx updates a volatile field, it appends a series
  // of MemBarVolatile nodes, one for *each* volatile field alias category.
  // The first membar is on the same memory slice as the field store opcode.
  // This forces the membar to follow the store.  (Bug 6500685 broke this.)
  // All the other membars (for other volatile slices, including AliasIdxBot,
  // which stands for all unknown volatile slices) are control-dependent
  // on the first membar.  This prevents later volatile loads or stores
  // from sliding up past the just-emitted store.

  MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
  mb->set_req(TypeFunc::Control,control());
  if (alias_idx == Compile::AliasIdxBot) {
    mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
  } else {
    assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
    mb->set_req(TypeFunc::Memory, memory(alias_idx));
  }
  Node* membar = _gvn.transform(mb);
  set_control(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Control)));
  if (alias_idx == Compile::AliasIdxBot) {
    merged_memory()->set_base_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory)));
  } else {
    set_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory)),alias_idx);
  }
  return membar;
}

//------------------------------shared_lock------------------------------------
// Emit locking code.
FastLockNode* GraphKit::shared_lock(Node* obj) {
  // bci is either a monitorenter bc or InvocationEntryBci
  // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
  assert(SynchronizationEntryBCI == InvocationEntryBci, "");

  if( !GenerateSynchronizationCode )
    return NULL;                // Not locking things?
  if (stopped())                // Dead monitor?
    return NULL;

  assert(dead_locals_are_killed(), "should kill locals before sync. point");

  // Box the stack location
  Node* box = _gvn.transform(new (C, 1) BoxLockNode(next_monitor()));
  Node* mem = reset_memory();

  FastLockNode * flock = _gvn.transform(new (C, 3) FastLockNode(0, obj, box) )->as_FastLock();
  if (PrintPreciseBiasedLockingStatistics) {
    // Create the counters for this fast lock.
    flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
  }
  // Add monitor to debug info for the slow path.  If we block inside the
  // slow path and de-opt, we need the monitor hanging around
  map()->push_monitor( flock );

  const TypeFunc *tf = LockNode::lock_type();
  LockNode *lock = new (C, tf->domain()->cnt()) LockNode(C, tf);

  lock->init_req( TypeFunc::Control, control() );
  lock->init_req( TypeFunc::Memory , mem );
  lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  lock->init_req( TypeFunc::FramePtr, frameptr() );
  lock->init_req( TypeFunc::ReturnAdr, top() );

  lock->init_req(TypeFunc::Parms + 0, obj);
  lock->init_req(TypeFunc::Parms + 1, box);
  lock->init_req(TypeFunc::Parms + 2, flock);
  add_safepoint_edges(lock);

  lock = _gvn.transform( lock )->as_Lock();

  // lock has no side-effects, sets few values
  set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);

  insert_mem_bar(Op_MemBarAcquire);

  // Add this to the worklist so that the lock can be eliminated
  record_for_igvn(lock);

#ifndef PRODUCT
  if (PrintLockStatistics) {
    // Update the counter for this lock.  Don't bother using an atomic
    // operation since we don't require absolute accuracy.
    lock->create_lock_counter(map()->jvms());
    increment_counter(lock->counter()->addr());
  }
#endif

  return flock;
}


//------------------------------shared_unlock----------------------------------
// Emit unlocking code.
void GraphKit::shared_unlock(Node* box, Node* obj) {
  // bci is either a monitorenter bc or InvocationEntryBci
  // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
  assert(SynchronizationEntryBCI == InvocationEntryBci, "");

  if( !GenerateSynchronizationCode )
    return;
  if (stopped()) {               // Dead monitor?
    map()->pop_monitor();        // Kill monitor from debug info
    return;
  }

  // Memory barrier to avoid floating things down past the locked region
  insert_mem_bar(Op_MemBarRelease);

  const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
  UnlockNode *unlock = new (C, tf->domain()->cnt()) UnlockNode(C, tf);
  uint raw_idx = Compile::AliasIdxRaw;
  unlock->init_req( TypeFunc::Control, control() );
  unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
  unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
  unlock->init_req( TypeFunc::FramePtr, frameptr() );
  unlock->init_req( TypeFunc::ReturnAdr, top() );

  unlock->init_req(TypeFunc::Parms + 0, obj);
  unlock->init_req(TypeFunc::Parms + 1, box);
  unlock = _gvn.transform(unlock)->as_Unlock();

  Node* mem = reset_memory();

  // unlock has no side-effects, sets few values
  set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);

  // Kill monitor from debug info
  map()->pop_monitor( );
}

//-------------------------------get_layout_helper-----------------------------
// If the given klass is a constant or known to be an array,
// fetch the constant layout helper value into constant_value
// and return (Node*)NULL.  Otherwise, load the non-constant
// layout helper value, and return the node which represents it.
// This two-faced routine is useful because allocation sites
// almost always feature constant types.
Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
  const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
  if (!StressReflectiveCode && inst_klass != NULL) {
    ciKlass* klass = inst_klass->klass();
    bool    xklass = inst_klass->klass_is_exact();
    if (xklass || klass->is_array_klass()) {
      jint lhelper = klass->layout_helper();
      if (lhelper != Klass::_lh_neutral_value) {
        constant_value = lhelper;
        return (Node*) NULL;
      }
    }
  }
  constant_value = Klass::_lh_neutral_value;  // put in a known value
  Node* lhp = basic_plus_adr(klass_node, klass_node, Klass::layout_helper_offset_in_bytes() + sizeof(oopDesc));
  return make_load(NULL, lhp, TypeInt::INT, T_INT);
}

// We just put in an allocate/initialize with a big raw-memory effect.
// Hook selected additional alias categories on the initialization.
static void hook_memory_on_init(GraphKit& kit, int alias_idx,
                                MergeMemNode* init_in_merge,
                                Node* init_out_raw) {
  DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
  assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");

  Node* prevmem = kit.memory(alias_idx);
  init_in_merge->set_memory_at(alias_idx, prevmem);
  kit.set_memory(init_out_raw, alias_idx);
}

//---------------------------set_output_for_allocation-------------------------
Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
                                          const TypeOopPtr* oop_type,
                                          bool raw_mem_only) {
  int rawidx = Compile::AliasIdxRaw;
  alloc->set_req( TypeFunc::FramePtr, frameptr() );
  add_safepoint_edges(alloc);
  Node* allocx = _gvn.transform(alloc);
  set_control( _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Control) ) );
  // create memory projection for i_o
  set_memory ( _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
  make_slow_call_ex(allocx, env()->OutOfMemoryError_klass(), true);

  // create a memory projection as for the normal control path
  Node* malloc = _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Memory));
  set_memory(malloc, rawidx);

  // a normal slow-call doesn't change i_o, but an allocation does
  // we create a separate i_o projection for the normal control path
  set_i_o(_gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::I_O, false) ) );
  Node* rawoop = _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Parms) );

  // put in an initialization barrier
  InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
                                                 rawoop)->as_Initialize();
  assert(alloc->initialization() == init,  "2-way macro link must work");
  assert(init ->allocation()     == alloc, "2-way macro link must work");
  if (ReduceFieldZeroing && !raw_mem_only) {
    // Extract memory strands which may participate in the new object's
    // initialization, and source them from the new InitializeNode.
    // This will allow us to observe initializations when they occur,
    // and link them properly (as a group) to the InitializeNode.
    assert(init->in(InitializeNode::Memory) == malloc, "");
    MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
    init->set_req(InitializeNode::Memory, minit_in);
    record_for_igvn(minit_in); // fold it up later, if possible
    Node* minit_out = memory(rawidx);
    assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
    if (oop_type->isa_aryptr()) {
      const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
      int            elemidx  = C->get_alias_index(telemref);
      hook_memory_on_init(*this, elemidx, minit_in, minit_out);
    } else if (oop_type->isa_instptr()) {
      ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
      for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
        ciField* field = ik->nonstatic_field_at(i);
        if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
          continue;  // do not bother to track really large numbers of fields
        // Find (or create) the alias category for this field:
        int fieldidx = C->alias_type(field)->index();
        hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
      }
    }
  }

  // Cast raw oop to the real thing...
  Node* javaoop = new (C, 2) CheckCastPPNode(control(), rawoop, oop_type);
  javaoop = _gvn.transform(javaoop);
  C->set_recent_alloc(control(), javaoop);
  assert(just_allocated_object(control()) == javaoop, "just allocated");

#ifdef ASSERT
  { // Verify that the AllocateNode::Ideal_allocation recognizers work:
    assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
           "Ideal_allocation works");
    assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
           "Ideal_allocation works");
    if (alloc->is_AllocateArray()) {
      assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
             "Ideal_allocation works");
      assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
             "Ideal_allocation works");
    } else {
      assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
    }
  }
#endif //ASSERT

  return javaoop;
}

//---------------------------new_instance--------------------------------------
// This routine takes a klass_node which may be constant (for a static type)
// or may be non-constant (for reflective code).  It will work equally well
// for either, and the graph will fold nicely if the optimizer later reduces
// the type to a constant.
// The optional arguments are for specialized use by intrinsics:
//  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
//  - If 'raw_mem_only', do not cast the result to an oop.
//  - If 'return_size_val', report the the total object size to the caller.
Node* GraphKit::new_instance(Node* klass_node,
                             Node* extra_slow_test,
                             bool raw_mem_only, // affect only raw memory
                             Node* *return_size_val) {
  // Compute size in doublewords
  // The size is always an integral number of doublewords, represented
  // as a positive bytewise size stored in the klass's layout_helper.
  // The layout_helper also encodes (in a low bit) the need for a slow path.
  jint  layout_con = Klass::_lh_neutral_value;
  Node* layout_val = get_layout_helper(klass_node, layout_con);
  int   layout_is_con = (layout_val == NULL);

  if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
  // Generate the initial go-slow test.  It's either ALWAYS (return a
  // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
  // case) a computed value derived from the layout_helper.
  Node* initial_slow_test = NULL;
  if (layout_is_con) {
    assert(!StressReflectiveCode, "stress mode does not use these paths");
    bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
    initial_slow_test = must_go_slow? intcon(1): extra_slow_test;

  } else {   // reflective case
    // This reflective path is used by Unsafe.allocateInstance.
    // (It may be stress-tested by specifying StressReflectiveCode.)
    // Basically, we want to get into the VM is there's an illegal argument.
    Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
    initial_slow_test = _gvn.transform( new (C, 3) AndINode(layout_val, bit) );
    if (extra_slow_test != intcon(0)) {
      initial_slow_test = _gvn.transform( new (C, 3) OrINode(initial_slow_test, extra_slow_test) );
    }
    // (Macro-expander will further convert this to a Bool, if necessary.)
  }

  // Find the size in bytes.  This is easy; it's the layout_helper.
  // The size value must be valid even if the slow path is taken.
  Node* size = NULL;
  if (layout_is_con) {
    size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
  } else {   // reflective case
    // This reflective path is used by clone and Unsafe.allocateInstance.
    size = ConvI2X(layout_val);

    // Clear the low bits to extract layout_helper_size_in_bytes:
    assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
    Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
    size = _gvn.transform( new (C, 3) AndXNode(size, mask) );
  }
  if (return_size_val != NULL) {
    (*return_size_val) = size;
  }

  // This is a precise notnull oop of the klass.
  // (Actually, it need not be precise if this is a reflective allocation.)
  // It's what we cast the result to.
  const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
  if (!tklass)  tklass = TypeKlassPtr::OBJECT;
  const TypeOopPtr* oop_type = tklass->as_instance_type();

  // Now generate allocation code

  // The entire memory state is needed for slow path of the allocation
  // since GC and deoptimization can happened.
  Node *mem = reset_memory();
  set_all_memory(mem); // Create new memory state

  AllocateNode* alloc
    = new (C, AllocateNode::ParmLimit)
        AllocateNode(C, AllocateNode::alloc_type(),
                     control(), mem, i_o(),
                     size, klass_node,
                     initial_slow_test);

  return set_output_for_allocation(alloc, oop_type, raw_mem_only);
}

//-------------------------------new_array-------------------------------------
// helper for both newarray and anewarray
// The 'length' parameter is (obviously) the length of the array.
// See comments on new_instance for the meaning of the other arguments.
Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
                          Node* length,         // number of array elements
                          int   nargs,          // number of arguments to push back for uncommon trap
                          bool raw_mem_only,    // affect only raw memory
                          Node* *return_size_val) {
  jint  layout_con = Klass::_lh_neutral_value;
  Node* layout_val = get_layout_helper(klass_node, layout_con);
  int   layout_is_con = (layout_val == NULL);

  if (!layout_is_con && !StressReflectiveCode &&
      !too_many_traps(Deoptimization::Reason_class_check)) {
    // This is a reflective array creation site.
    // Optimistically assume that it is a subtype of Object[],
    // so that we can fold up all the address arithmetic.
    layout_con = Klass::array_layout_helper(T_OBJECT);
    Node* cmp_lh = _gvn.transform( new(C, 3) CmpINode(layout_val, intcon(layout_con)) );
    Node* bol_lh = _gvn.transform( new(C, 2) BoolNode(cmp_lh, BoolTest::eq) );
    { BuildCutout unless(this, bol_lh, PROB_MAX);
      _sp += nargs;
      uncommon_trap(Deoptimization::Reason_class_check,
                    Deoptimization::Action_maybe_recompile);
    }
    layout_val = NULL;
    layout_is_con = true;
  }

  // Generate the initial go-slow test.  Make sure we do not overflow
  // if length is huge (near 2Gig) or negative!  We do not need
  // exact double-words here, just a close approximation of needed
  // double-words.  We can't add any offset or rounding bits, lest we
  // take a size -1 of bytes and make it positive.  Use an unsigned
  // compare, so negative sizes look hugely positive.
  int fast_size_limit = FastAllocateSizeLimit;
  if (layout_is_con) {
    assert(!StressReflectiveCode, "stress mode does not use these paths");
    // Increase the size limit if we have exact knowledge of array type.
    int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
    fast_size_limit <<= (LogBytesPerLong - log2_esize);
  }

  Node* initial_slow_cmp  = _gvn.transform( new (C, 3) CmpUNode( length, intcon( fast_size_limit ) ) );
  Node* initial_slow_test = _gvn.transform( new (C, 2) BoolNode( initial_slow_cmp, BoolTest::gt ) );
  if (initial_slow_test->is_Bool()) {
    // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
    initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
  }

  // --- Size Computation ---
  // array_size = round_to_heap(array_header + (length << elem_shift));
  // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
  // and round_to(x, y) == ((x + y-1) & ~(y-1))
  // The rounding mask is strength-reduced, if possible.
  int round_mask = MinObjAlignmentInBytes - 1;
  Node* header_size = NULL;
  int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  // (T_BYTE has the weakest alignment and size restrictions...)
  if (layout_is_con) {
    int       hsize  = Klass::layout_helper_header_size(layout_con);
    int       eshift = Klass::layout_helper_log2_element_size(layout_con);
    BasicType etype  = Klass::layout_helper_element_type(layout_con);
    if ((round_mask & ~right_n_bits(eshift)) == 0)
      round_mask = 0;  // strength-reduce it if it goes away completely
    assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
    assert(header_size_min <= hsize, "generic minimum is smallest");
    header_size_min = hsize;
    header_size = intcon(hsize + round_mask);
  } else {
    Node* hss   = intcon(Klass::_lh_header_size_shift);
    Node* hsm   = intcon(Klass::_lh_header_size_mask);
    Node* hsize = _gvn.transform( new(C, 3) URShiftINode(layout_val, hss) );
    hsize       = _gvn.transform( new(C, 3) AndINode(hsize, hsm) );
    Node* mask  = intcon(round_mask);
    header_size = _gvn.transform( new(C, 3) AddINode(hsize, mask) );
  }

  Node* elem_shift = NULL;
  if (layout_is_con) {
    int eshift = Klass::layout_helper_log2_element_size(layout_con);
    if (eshift != 0)
      elem_shift = intcon(eshift);
  } else {
    // There is no need to mask or shift this value.
    // The semantics of LShiftINode include an implicit mask to 0x1F.
    assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
    elem_shift = layout_val;
  }

  // Transition to native address size for all offset calculations:
  Node* lengthx = ConvI2X(length);
  Node* headerx = ConvI2X(header_size);
#ifdef _LP64
  { const TypeLong* tllen = _gvn.find_long_type(lengthx);
    if (tllen != NULL && tllen->_lo < 0) {
      // Add a manual constraint to a positive range.  Cf. array_element_address.
      jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
      if (size_max > tllen->_hi)  size_max = tllen->_hi;
      const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
      lengthx = _gvn.transform( new (C, 2) ConvI2LNode(length, tlcon));
    }
  }
#endif

  // Combine header size (plus rounding) and body size.  Then round down.
  // This computation cannot overflow, because it is used only in two
  // places, one where the length is sharply limited, and the other
  // after a successful allocation.
  Node* abody = lengthx;
  if (elem_shift != NULL)
    abody     = _gvn.transform( new(C, 3) LShiftXNode(lengthx, elem_shift) );
  Node* size  = _gvn.transform( new(C, 3) AddXNode(headerx, abody) );
  if (round_mask != 0) {
    Node* mask = MakeConX(~round_mask);
    size       = _gvn.transform( new(C, 3) AndXNode(size, mask) );
  }
  // else if round_mask == 0, the size computation is self-rounding

  if (return_size_val != NULL) {
    // This is the size
    (*return_size_val) = size;
  }

  // Now generate allocation code

  // The entire memory state is needed for slow path of the allocation
  // since GC and deoptimization can happened.
  Node *mem = reset_memory();
  set_all_memory(mem); // Create new memory state

  // Create the AllocateArrayNode and its result projections
  AllocateArrayNode* alloc
    = new (C, AllocateArrayNode::ParmLimit)
        AllocateArrayNode(C, AllocateArrayNode::alloc_type(),
                          control(), mem, i_o(),
                          size, klass_node,
                          initial_slow_test,
                          length);

  // Cast to correct type.  Note that the klass_node may be constant or not,
  // and in the latter case the actual array type will be inexact also.
  // (This happens via a non-constant argument to inline_native_newArray.)
  // In any case, the value of klass_node provides the desired array type.
  const TypeInt* length_type = _gvn.find_int_type(length);
  const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
  if (ary_type->isa_aryptr() && length_type != NULL) {
    // Try to get a better type than POS for the size
    ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
  }

  Node* javaoop = set_output_for_allocation(alloc, ary_type, raw_mem_only);

  // Cast length on remaining path to be as narrow as possible
  if (map()->find_edge(length) >= 0) {
    Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
    if (ccast != length) {
      _gvn.set_type_bottom(ccast);
      record_for_igvn(ccast);
      replace_in_map(length, ccast);
    }
  }

  return javaoop;
}

// The following "Ideal_foo" functions are placed here because they recognize
// the graph shapes created by the functions immediately above.

//---------------------------Ideal_allocation----------------------------------
// Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
  if (ptr == NULL) {     // reduce dumb test in callers
    return NULL;
  }
  if (ptr->is_CheckCastPP()) {  // strip a raw-to-oop cast
    ptr = ptr->in(1);
    if (ptr == NULL)  return NULL;
  }
  if (ptr->is_Proj()) {
    Node* allo = ptr->in(0);
    if (allo != NULL && allo->is_Allocate()) {
      return allo->as_Allocate();
    }
  }
  // Report failure to match.
  return NULL;
}

// Fancy version which also strips off an offset (and reports it to caller).
AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
                                             intptr_t& offset) {
  Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
  if (base == NULL)  return NULL;
  return Ideal_allocation(base, phase);
}

// Trace Initialize <- Proj[Parm] <- Allocate
AllocateNode* InitializeNode::allocation() {
  Node* rawoop = in(InitializeNode::RawAddress);
  if (rawoop->is_Proj()) {
    Node* alloc = rawoop->in(0);
    if (alloc->is_Allocate()) {
      return alloc->as_Allocate();
    }
  }
  return NULL;
}

// Trace Allocate -> Proj[Parm] -> Initialize
InitializeNode* AllocateNode::initialization() {
  ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
  if (rawoop == NULL)  return NULL;
  for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
    Node* init = rawoop->fast_out(i);
    if (init->is_Initialize()) {
      assert(init->as_Initialize()->allocation() == this, "2-way link");
      return init->as_Initialize();
    }
  }
  return NULL;
}

//----------------------------- loop predicates ---------------------------

//------------------------------add_predicate_impl----------------------------
void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
  // Too many traps seen?
  if (too_many_traps(reason)) {
#ifdef ASSERT
    if (TraceLoopPredicate) {
      int tc = C->trap_count(reason);
      tty->print("too many traps=%s tcount=%d in ",
                    Deoptimization::trap_reason_name(reason), tc);
      method()->print(); // which method has too many predicate traps
      tty->cr();
    }
#endif
    // We cannot afford to take more traps here,
    // do not generate predicate.
    return;
  }

  Node *cont    = _gvn.intcon(1);
  Node* opq     = _gvn.transform(new (C, 2) Opaque1Node(C, cont));
  Node *bol     = _gvn.transform(new (C, 2) Conv2BNode(opq));
  IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
  Node* iffalse = _gvn.transform(new (C, 1) IfFalseNode(iff));
  C->add_predicate_opaq(opq);
  {
    PreserveJVMState pjvms(this);
    set_control(iffalse);
    _sp += nargs;
    uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
  }
  Node* iftrue = _gvn.transform(new (C, 1) IfTrueNode(iff));
  set_control(iftrue);
}

//------------------------------add_predicate---------------------------------
void GraphKit::add_predicate(int nargs) {
  if (UseLoopPredicate) {
    add_predicate_impl(Deoptimization::Reason_predicate, nargs);
  }
}

//----------------------------- store barriers ----------------------------
#define __ ideal.

void GraphKit::sync_kit(IdealKit& ideal) {
  // Final sync IdealKit and graphKit.
  __ drain_delay_transform();
  set_all_memory(__ merged_memory());
  set_control(__ ctrl());
}

// vanilla/CMS post barrier
// Insert a write-barrier store.  This is to let generational GC work; we have
// to flag all oop-stores before the next GC point.
void GraphKit::write_barrier_post(Node* oop_store,
                                  Node* obj,
                                  Node* adr,
                                  uint  adr_idx,
                                  Node* val,
                                  bool use_precise) {
  // No store check needed if we're storing a NULL or an old object
  // (latter case is probably a string constant). The concurrent
  // mark sweep garbage collector, however, needs to have all nonNull
  // oop updates flagged via card-marks.
  if (val != NULL && val->is_Con()) {
    // must be either an oop or NULL
    const Type* t = val->bottom_type();
    if (t == TypePtr::NULL_PTR || t == Type::TOP)
      // stores of null never (?) need barriers
      return;
    ciObject* con = t->is_oopptr()->const_oop();
    if (con != NULL
        && con->is_perm()
        && Universe::heap()->can_elide_permanent_oop_store_barriers())
      // no store barrier needed, because no old-to-new ref created
      return;
  }

  if (use_ReduceInitialCardMarks()
      && obj == just_allocated_object(control())) {
    // We can skip marks on a freshly-allocated object in Eden.
    // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
    // That routine informs GC to take appropriate compensating steps,
    // upon a slow-path allocation, so as to make this card-mark
    // elision safe.
    return;
  }

  if (!use_precise) {
    // All card marks for a (non-array) instance are in one place:
    adr = obj;
  }
  // (Else it's an array (or unknown), and we want more precise card marks.)
  assert(adr != NULL, "");

  IdealKit ideal(gvn(), control(), merged_memory(), true);

  // Convert the pointer to an int prior to doing math on it
  Node* cast = __ CastPX(__ ctrl(), adr);

  // Divide by card size
  assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
         "Only one we handle so far.");
  Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );

  // Combine card table base and card offset
  Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );

  // Get the alias_index for raw card-mark memory
  int adr_type = Compile::AliasIdxRaw;
  // Smash zero into card
  Node*   zero = __ ConI(0);
  BasicType bt = T_BYTE;
  if( !UseConcMarkSweepGC ) {
    __ store(__ ctrl(), card_adr, zero, bt, adr_type);
  } else {
    // Specialized path for CM store barrier
    __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
  }

  // Final sync IdealKit and GraphKit.
  sync_kit(ideal);
}

// G1 pre/post barriers
void GraphKit::g1_write_barrier_pre(bool do_load,
                                    Node* obj,
                                    Node* adr,
                                    uint alias_idx,
                                    Node* val,
                                    const TypeOopPtr* val_type,
                                    Node* pre_val,
                                    BasicType bt) {

  // Some sanity checks
  // Note: val is unused in this routine.

  if (do_load) {
    // We need to generate the load of the previous value
    assert(obj != NULL, "must have a base");
    assert(adr != NULL, "where are loading from?");
    assert(pre_val == NULL, "loaded already?");
    assert(val_type != NULL, "need a type");
  } else {
    // In this case both val_type and alias_idx are unused.
    assert(pre_val != NULL, "must be loaded already");
    assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
  }
  assert(bt == T_OBJECT, "or we shouldn't be here");

  IdealKit ideal(gvn(), control(), merged_memory(), true);

  Node* tls = __ thread(); // ThreadLocalStorage

  Node* no_ctrl = NULL;
  Node* no_base = __ top();
  Node* zero = __ ConI(0);

  float likely  = PROB_LIKELY(0.999);
  float unlikely  = PROB_UNLIKELY(0.999);

  BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
  assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");

  // Offsets into the thread
  const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
                                          PtrQueue::byte_offset_of_active());
  const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
                                          PtrQueue::byte_offset_of_index());
  const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
                                          PtrQueue::byte_offset_of_buf());

  // Now the actual pointers into the thread
  Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
  Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
  Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));

  // Now some of the values
  Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);

  // if (!marking)
  __ if_then(marking, BoolTest::ne, zero); {
    Node* index   = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw);

    if (do_load) {
      // load original value
      // alias_idx correct??
      pre_val = __ load(no_ctrl, adr, val_type, bt, alias_idx);
    }

    // if (pre_val != NULL)
    __ if_then(pre_val, BoolTest::ne, null()); {
      Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);

      // is the queue for this thread full?
      __ if_then(index, BoolTest::ne, zero, likely); {

        // decrement the index
        Node* next_index = __ SubI(index,  __ ConI(sizeof(intptr_t)));
        Node* next_indexX = next_index;
#ifdef _LP64
        // We could refine the type for what it's worth
        // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue);
        next_indexX = _gvn.transform( new (C, 2) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) );
#endif

        // Now get the buffer location we will log the previous value into and store it
        Node *log_addr = __ AddP(no_base, buffer, next_indexX);
        __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw);
        // update the index
        __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw);

      } __ else_(); {

        // logging buffer is full, call the runtime
        const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
        __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
      } __ end_if();  // (!index)
    } __ end_if();  // (pre_val != NULL)
  } __ end_if();  // (!marking)

  // Final sync IdealKit and GraphKit.
  sync_kit(ideal);
}

//
// Update the card table and add card address to the queue
//
void GraphKit::g1_mark_card(IdealKit& ideal,
                            Node* card_adr,
                            Node* oop_store,
                            uint oop_alias_idx,
                            Node* index,
                            Node* index_adr,
                            Node* buffer,
                            const TypeFunc* tf) {

  Node* zero = __ ConI(0);
  Node* no_base = __ top();
  BasicType card_bt = T_BYTE;
  // Smash zero into card. MUST BE ORDERED WRT TO STORE
  __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);

  //  Now do the queue work
  __ if_then(index, BoolTest::ne, zero); {

    Node* next_index = __ SubI(index, __ ConI(sizeof(intptr_t)));
    Node* next_indexX = next_index;
#ifdef _LP64
    // We could refine the type for what it's worth
    // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue);
    next_indexX = _gvn.transform( new (C, 2) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) );
#endif // _LP64
    Node* log_addr = __ AddP(no_base, buffer, next_indexX);

    __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw);
    __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw);

  } __ else_(); {
    __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
  } __ end_if();

}

void GraphKit::g1_write_barrier_post(Node* oop_store,
                                     Node* obj,
                                     Node* adr,
                                     uint alias_idx,
                                     Node* val,
                                     BasicType bt,
                                     bool use_precise) {
  // If we are writing a NULL then we need no post barrier

  if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
    // Must be NULL
    const Type* t = val->bottom_type();
    assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
    // No post barrier if writing NULLx
    return;
  }

  if (!use_precise) {
    // All card marks for a (non-array) instance are in one place:
    adr = obj;
  }
  // (Else it's an array (or unknown), and we want more precise card marks.)
  assert(adr != NULL, "");

  IdealKit ideal(gvn(), control(), merged_memory(), true);

  Node* tls = __ thread(); // ThreadLocalStorage

  Node* no_base = __ top();
  float likely  = PROB_LIKELY(0.999);
  float unlikely  = PROB_UNLIKELY(0.999);
  Node* zero = __ ConI(0);
  Node* zeroX = __ ConX(0);

  // Get the alias_index for raw card-mark memory
  const TypePtr* card_type = TypeRawPtr::BOTTOM;

  const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();

  // Offsets into the thread
  const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
                                     PtrQueue::byte_offset_of_index());
  const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
                                     PtrQueue::byte_offset_of_buf());

  // Pointers into the thread

  Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
  Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));

  // Now some values
  // Use ctrl to avoid hoisting these values past a safepoint, which could
  // potentially reset these fields in the JavaThread.
  Node* index  = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw);
  Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);

  // Convert the store obj pointer to an int prior to doing math on it
  // Must use ctrl to prevent "integerized oop" existing across safepoint
  Node* cast =  __ CastPX(__ ctrl(), adr);

  // Divide pointer by card size
  Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );

  // Combine card table base and card offset
  Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );

  // If we know the value being stored does it cross regions?

  if (val != NULL) {
    // Does the store cause us to cross regions?

    // Should be able to do an unsigned compare of region_size instead of
    // and extra shift. Do we have an unsigned compare??
    // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
    Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));

    // if (xor_res == 0) same region so skip
    __ if_then(xor_res, BoolTest::ne, zeroX); {

      // No barrier if we are storing a NULL
      __ if_then(val, BoolTest::ne, null(), unlikely); {

        // Ok must mark the card if not already dirty

        // load the original value of the card
        Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);

        __ if_then(card_val, BoolTest::ne, zero); {
          g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
        } __ end_if();
      } __ end_if();
    } __ end_if();
  } else {
    // Object.clone() instrinsic uses this path.
    g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
  }

  // Final sync IdealKit and GraphKit.
  sync_kit(ideal);
}
#undef __