jdk8-mips64-public/hotspot: src/share/vm/opto/graphKit.cpp@c1c199dde5c9 (annotated)

src/share/vm/opto/graphKit.cpp@c1c199dde5c9 (annotated)

src/share/vm/opto/graphKit.cpp

Wed, 03 Jun 2015 14:22:57 +0200

author: roland
date: Wed, 03 Jun 2015 14:22:57 +0200
changeset 7859: c1c199dde5c9
parent 7858: 55d07ec5bde4
child 7994: 04ff2f6cd0eb
child 8285: 535618ab1c04
permissions: -rw-r--r--

8077504: Unsafe load can loose control dependency and cause crash
Summary: Node::depends_only_on_test() should return false for Unsafe loads
Reviewed-by: kvn, adinn

 /*
  * Copyright (c) 2001, 2015, 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;
 }
 //--------------------------------sync_jvms_for_reexecute---------------------
 // Make sure our current jvms agrees with our parse state.  This version
 // uses the reexecute_sp for reexecuting bytecodes.
 JVMState* GraphKit::sync_jvms_for_reexecute() {
   JVMState* jvms = this->jvms();
   jvms->set_bci(bci());          // Record the new bci in the JVMState
   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
   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, C); // 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) 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_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
   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) 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 = dst->as_Phi();
       }
       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_speculative(srctype);
         if (phi->type() != dsttype) {
           phi->set_type(dsttype);
           _gvn.set_type(phi, dsttype);
         }
       }
     }
   }
   phi_map->merge_replaced_nodes_with(ex_map);
 }
 //--------------------------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) 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, MemNode::unordered);
     // Test the should_post_on_exceptions_flag vs. 0
     Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) );
     Node* tst = _gvn.transform( new (C) 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());
       // Conservatively release stores of object references.
       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
       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.
   assert(!Deoptimization::reason_is_speculate(reason), "unsupported");
   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
   if (treat_throw_as_hot
       && (method()->method_data()->trap_recompiled_at(bci(), NULL)
           || 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) IfTrueNode(iff) ));
   inner_map->set_control(kit->gvn().transform( new (kit->C) 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.
   // If the bytecode needs to be reexecuted we need to put
   // the arguments back on the stack.
   const bool should_reexecute = jvms()->should_reexecute();
   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
   // undefined if the bci is different.  This is normal for Parse but it
   // should not happen for LibraryCallKit because only one bci is processed.
   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
          "in LibraryCallKit the reexecute bit should not change");
   // 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 ignored_will_link;
       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
       int      size  = field->type()->size();
       bool is_get = (depth >= 0), is_static = (depth & 1);
       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 ignored_will_link;
       ciSignature* declared_signature = NULL;
       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
       assert(declared_signature != NULL, "cannot be null");
       inputs   = declared_signature->arg_size_for_bc(code);
       int size = declared_signature->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) 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((jlong) offset_con);
   }
   return _gvn.transform( new (C) ConvI2LNode(offset));
 }
 Node* GraphKit::ConvI2UL(Node* offset) {
   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
   if (offset_con != (juint) Type::OffsetBot) {
     return longcon((julong) offset_con);
   }
   Node* conv = _gvn.transform( new (C) ConvI2LNode(offset));
   Node* mask = _gvn.transform( ConLNode::make(C, (julong) max_juint) );
   return _gvn.transform( new (C) AndLNode(conv, mask) );
 }
 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) 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, NULL, 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) 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) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
     case T_INT    : chk = new (C) 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->remove_speculative()) {
           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
           explicit_null_checks_elided++;
           return value;           // Elided null check quickly!
         }
       }
       chk = new (C) CmpPNode( value, null() );
       break;
     }
     default:
       fatal(err_msg_res("unexpected type: %s", type2name(type)));
   }
   assert(chk != NULL, "sanity check");
   chk = _gvn.transform(chk);
   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
   BoolNode *btst = new (C) 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) IfFalseNode(iff));
     set_control(      _gvn.transform( new (C) 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_speculative(TypePtr::NOTNULL);
   // Object is already not-null?
   if( t == t_not_null ) return obj;
   Node *cast = new (C) 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) {
   if (old == neww) {
     return;
   }
   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.
   // don't let inconsistent types from profiling escape this
   // method
   const Type* told = _gvn.type(old);
   const Type* tnew = _gvn.type(neww);
   if (!tnew->higher_equal(told)) {
     return;
   }
   map()->record_replaced_node(old, neww);
 }
 //=============================================================================
 //--------------------------------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) 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,
                           MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency, 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, mo, control_dependency);
   } else if (require_atomic_access && bt == T_DOUBLE) {
     ld = LoadDNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo, control_dependency);
   } else {
     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency);
   }
   ld = _gvn.transform(ld);
   if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
     // Improve graph before escape analysis and boxing elimination.
     record_for_igvn(ld);
   }
   return ld;
 }
 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
                                 int adr_idx,
                                 MemNode::MemOrd mo,
                                 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, mo);
   } else if (require_atomic_access && bt == T_DOUBLE) {
     st = StoreDNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo);
   } else {
     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
   }
   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();
   }
 }
 bool GraphKit::can_move_pre_barrier() const {
   BarrierSet* bs = Universe::heap()->barrier_set();
   switch (bs->kind()) {
     case BarrierSet::G1SATBCT:
     case BarrierSet::G1SATBCTLogging:
       return true; // Can move it if no safepoint
     case BarrierSet::CardTableModRef:
     case BarrierSet::CardTableExtension:
     case BarrierSet::ModRef:
       return true; // There is no pre-barrier
     case BarrierSet::Other:
     default      :
       ShouldNotReachHere();
   }
   return false;
 }
 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,
                           MemNode::MemOrd mo) {
   // Transformation of a value which could be NULL pointer (CastPP #NULL)
   // could be delayed during Parse (for example, in adjust_map_after_if()).
   // Execute transformation here to avoid barrier generation in such case.
   if (_gvn.type(val) == TypePtr::NULL_PTR)
     val = _gvn.makecon(TypePtr::NULL_PTR);
   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, mo);
   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,
                              MemNode::MemOrd mo) {
   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, mo);
 }
 //-------------------------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) ConvI2LNode(idx, lidxtype) );
 #endif
   Node* scale = _gvn.transform( new (C) 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, MemNode::unordered);
   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) ProjNode(call, TypeFunc::Control)));
   set_i_o(    _gvn.transform(new (C) 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) 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) ProjNode(call, TypeFunc::I_O) ));
     set_all_memory(_gvn.transform( new (C) 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) 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) 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, bool do_replaced_nodes) {
   JVMState* ejvms = NULL;
   if (has_exceptions()) {
     ejvms = transfer_exceptions_into_jvms();
   }
   ReplacedNodes replaced_nodes = map()->replaced_nodes();
   ReplacedNodes replaced_nodes_exception;
   Node* ex_ctl = top();
   SafePointNode* final_state = stop();
   // Find all the needed outputs of this call
   CallProjections callprojs;
   call->extract_projections(&callprojs, true);
   Node* init_mem = call->in(TypeFunc::Memory);
   Node* final_mem = final_state->in(TypeFunc::Memory);
   Node* final_ctl = final_state->in(TypeFunc::Control);
   Node* final_io = final_state->in(TypeFunc::I_O);
   // Replace all the old call edges with the edges from the inlining result
   if (callprojs.fallthrough_catchproj != NULL) {
     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
   }
   if (callprojs.fallthrough_memproj != NULL) {
     if (final_mem->is_MergeMem()) {
       // Parser's exits MergeMem was not transformed but may be optimized
       final_mem = _gvn.transform(final_mem);
     }
     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
   }
   if (callprojs.fallthrough_ioproj != NULL) {
     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
   }
   // 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
     if (callprojs.catchall_catchproj != NULL) {
       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
     }
     if (callprojs.catchall_memproj != NULL) {
       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
     }
     if (callprojs.catchall_ioproj != NULL) {
       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();
     replaced_nodes_exception = ex_map->replaced_nodes();
     Node* ex_oop = ekit.use_exception_state(ex_map);
     if (callprojs.catchall_catchproj != NULL) {
       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
       ex_ctl = ekit.control();
     }
     if (callprojs.catchall_memproj != NULL) {
       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
     }
     if (callprojs.catchall_ioproj != NULL) {
       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);
   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());
     }
   }
   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
     replaced_nodes.apply(C, final_ctl);
   }
   if (!ex_ctl->is_top() && do_replaced_nodes) {
     replaced_nodes_exception.apply(C, ex_ctl);
   }
 }
 //------------------------------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, MemNode::unordered);
   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
 }
 //------------------------------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.
   // Set the stack pointer to the right value for reexecution:
   set_sp(reexecute_sp());
 #ifdef ASSERT
   if (!must_throw) {
     // Make sure the stack has at least enough depth to execute
     // the current bytecode.
     int inputs, ignored_depth;
     if (compute_stack_effects(inputs, ignored_depth)) {
       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
              Bytecodes::name(java_bc()), sp(), inputs));
     }
   }
 #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.
       if (C->log() != NULL) {
         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
                 Deoptimization::trap_reason_name(reason),
                 Deoptimization::trap_action_name(action));
       }
       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:
     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
     break;
 #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) 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);
     }
   }
 }
 /**
  * Record profiling data exact_kls for Node n with the type system so
  * that it can propagate it (speculation)
  *
  * @param n          node that the type applies to
  * @param exact_kls  type from profiling
  *
  * @return           node with improved type
  */
 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls) {
   const Type* current_type = _gvn.type(n);
   assert(UseTypeSpeculation, "type speculation must be on");
   const TypeOopPtr* speculative = current_type->speculative();
   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
     const TypeOopPtr* xtype = tklass->as_instance_type();
     assert(xtype->klass_is_exact(), "Should be exact");
     // record the new speculative type's depth
     speculative = xtype->with_inline_depth(jvms()->depth());
   }
   if (speculative != current_type->speculative()) {
     // Build a type with a speculative type (what we think we know
     // about the type but will need a guard when we use it)
     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
     // We're changing the type, we need a new CheckCast node to carry
     // the new type. The new type depends on the control: what
     // profiling tells us is only valid from here as far as we can
     // tell.
     Node* cast = new(C) CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
     cast = _gvn.transform(cast);
     replace_in_map(n, cast);
     n = cast;
   }
   return n;
 }
 /**
  * Record profiling data from receiver profiling at an invoke with the
  * type system so that it can propagate it (speculation)
  *
  * @param n  receiver node
  *
  * @return   node with improved type
  */
 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
   if (!UseTypeSpeculation) {
     return n;
   }
   ciKlass* exact_kls = profile_has_unique_klass();
   return record_profile_for_speculation(n, exact_kls);
 }
 /**
  * Record profiling data from argument profiling at an invoke with the
  * type system so that it can propagate it (speculation)
  *
  * @param dest_method  target method for the call
  * @param bc           what invoke bytecode is this?
  */
 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
   if (!UseTypeSpeculation) {
     return;
   }
   const TypeFunc* tf    = TypeFunc::make(dest_method);
   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
       ciKlass* better_type = method()->argument_profiled_type(bci(), i);
       if (better_type != NULL) {
         record_profile_for_speculation(argument(j), better_type);
       }
       i++;
     }
   }
 }
 /**
  * Record profiling data from parameter profiling at an invoke with
  * the type system so that it can propagate it (speculation)
  */
 void GraphKit::record_profiled_parameters_for_speculation() {
   if (!UseTypeSpeculation) {
     return;
   }
   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
     if (_gvn.type(local(i))->isa_oopptr()) {
       ciKlass* better_type = method()->parameter_profiled_type(j);
       if (better_type != NULL) {
         record_profile_for_speculation(local(i), better_type);
       }
       j++;
     }
   }
 }
 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) 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) 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) 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, bool safe_for_replace) {
   // 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
   }
   if ((*null_control) == top() && safe_for_replace) {
     replace_in_map(value, cast);
   }
   // 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) 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) 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
   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) CallStaticJavaNode(call_type, call_addr, call_name,
                                            bci(), adr_type);
   } else if (flags & RC_NO_FP) {
     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
   } else {
     call = new(C) 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) 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 (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
         if (mms.is_empty()) {
           // clone base memory Phi's inputs for this memory slice
           assert(old_slice == mms.base_memory(), "sanity");
           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
           _gvn.set_type(phi, Type::MEMORY);
           for (uint i = 1; i < phi->req(); i++) {
             phi->init_req(i, old_slice->in(i));
           }
         } else {
           phi = old_slice->as_Phi(); // Phi was generated already
         }
       } 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(phi);
     }
   }
 }
 //------------------------------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, bool deoptimize) {
   if (stopped())  return;
   // Make a catch node with just two handlers:  fall-through and catch-all
   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
   { PreserveJVMState pjvms(this);
     set_control(excp);
     set_i_o(i_o);
     if (excp != top()) {
       if (deoptimize) {
         // Deoptimize if an exception is caught. Don't construct exception state in this case.
         uncommon_trap(Deoptimization::Reason_unhandled,
                       Deoptimization::Action_none);
       } else {
         // 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) 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) CmpPNode(subklass, superklass) );
         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
         return       _gvn.transform( new(C) 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, in_bytes(Klass::super_check_offset_offset()) );
   Node *chk_off = _gvn.transform(new (C) LoadINode(NULL, memory(p1), p1, _gvn.type(p1)->is_ptr(),
                                                    TypeInt::INT, MemNode::unordered));
   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
   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) 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, NULL, 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) CmpPNode( superklass, nkls ) );
   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
   set_control(    _gvn.transform( new (C) 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) RegionNode(4);
   record_for_igvn(r_ok_subtype);
   RegionNode *r_not_subtype = new (C) 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) CmpINode( chk_off, cacheoff ) );
   Node *bol2 = _gvn.transform( new (C) 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) IfTrueNode (iff2) ) );
   set_control(                _gvn.transform( new (C) 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) CmpPNode( subklass, superklass ) );
   Node *bol3 = _gvn.transform( new (C) 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) IfTrueNode ( iff3 ) ) );
   set_control(               _gvn.transform( new (C) 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) PartialSubtypeCheckNode(control(), subklass, superklass) );
   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
   Node *bol4 = _gvn.transform( new (C) 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) IfTrueNode (iff4) ) );
   r_ok_subtype ->init_req(3, _gvn.transform( new (C) 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) CmpPNode(recv_klass, want_klass) );
   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
   Node* fail = _gvn.transform( new(C) 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) 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,
                                              ciKlass* require_klass,
                                              ciKlass* spec_klass,
                                              bool safe_for_replace) {
   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
   Deoptimization::DeoptReason reason = spec_klass == NULL ? Deoptimization::Reason_class_check : Deoptimization::Reason_speculate_class_check;
   // Make sure we haven't already deoptimized from this tactic.
   if (too_many_traps(reason) || too_many_recompiles(reason))
     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...)
   // If we have a speculative type use it instead of profiling (which
   // may not help us)
   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
   if (exact_kls != NULL) {// no cast failures here
     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 or
       // the speculative type, 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_exact(reason, Deoptimization::Action_maybe_recompile);
       }
       if (safe_for_replace) {
         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;
 }
 /**
  * Cast obj to type and emit guard unless we had too many traps here
  * already
  *
  * @param obj       node being casted
  * @param type      type to cast the node to
  * @param not_null  true if we know node cannot be null
  */
 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
                                         ciKlass* type,
                                         bool not_null) {
   // type == NULL if profiling tells us this object is always null
   if (type != NULL) {
     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_null_check;
     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
         !too_many_traps(class_reason) && !too_many_recompiles(class_reason)) {
       Node* not_null_obj = NULL;
       // not_null is true if we know the object is not null and
       // there's no need for a null check
       if (!not_null) {
         Node* null_ctl = top();
         not_null_obj = null_check_oop(obj, &null_ctl, true, true);
         assert(null_ctl->is_top(), "no null control here");
       } else {
         not_null_obj = obj;
       }
       Node* exact_obj = not_null_obj;
       ciKlass* exact_kls = type;
       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
                                             &exact_obj);
       {
         PreserveJVMState pjvms(this);
         set_control(slow_ctl);
         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
       }
       replace_in_map(not_null_obj, exact_obj);
       obj = exact_obj;
     }
   } else {
     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
       Node* exact_obj = null_assert(obj);
       replace_in_map(obj, exact_obj);
       obj = exact_obj;
     }
   }
   return obj;
 }
 //-------------------------------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, bool safe_for_replace) {
   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) RegionNode(PATH_LIMIT);
   Node*       phi    = new(C) 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, safe_for_replace);
   // 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);
   }
   // Do we know the type check always succeed?
   bool known_statically = false;
   if (_gvn.type(superklass)->singleton()) {
     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
     if (subk != NULL && subk->is_loaded()) {
       int static_res = static_subtype_check(superk, subk);
       known_statically = (static_res == SSC_always_true || static_res == SSC_always_false);
     }
   }
   if (known_statically && UseTypeSpeculation) {
     // If we know the type check always succeeds then we don't use the
     // profiling data at this bytecode. Don't lose it, feed it to the
     // type system as a speculative type.
     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
   } else {
     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
     // We may not have profiling here or it may not help us. If we
     // have a speculative type use it to perform an exact cast.
     ciKlass* spec_obj_type = obj_type->speculative_type();
     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
       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:
         // If we know the type check always succeed then we don't use
         // the profiling data at this bytecode. Don't lose it, feed it
         // to the type system as a speculative type.
         return record_profiled_receiver_for_speculation(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 null_assert(obj);
       }
     }
   }
   ciProfileData* data = NULL;
   bool safe_for_replace = false;
   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());
     safe_for_replace = true;
   }
   // Make the merge point
   enum { _obj_path = 1, _null_path, PATH_LIMIT };
   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
   Node*       phi    = new (C) 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, safe_for_replace);
   // 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 (tk->klass_is_exact()) {
     // The following optimization tries to statically cast the speculative type of the object
     // (for example obtained during profiling) to the type of the superklass and then do a
     // dynamic check that the type of the object is what we expect. To work correctly
     // for checkcast and aastore the type of superklass should be exact.
     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
     // We may not have profiling here or it may not help us. If we have
     // a speculative type use it to perform an exact cast.
     ciKlass* spec_obj_type = obj_type->speculative_type();
     if (spec_obj_type != NULL ||
         (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, tk->klass(), spec_obj_type, safe_for_replace);
       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_speculative(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) 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) 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) ProjNode(membar, TypeFunc::Control)));
   if (alias_idx == Compile::AliasIdxBot) {
     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
   } else {
     set_memory(_gvn.transform(new (C) 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) BoxLockNode(next_monitor()));
   Node* mem = reset_memory();
   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
     // Create the counters for this fast lock.
     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
   }
   // Create the rtm counters for this fast lock if needed.
   flock->create_rtm_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) 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_MemBarAcquireLock);
   // 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_MemBarReleaseLock);
   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
   UnlockNode *unlock = new (C) UnlockNode(C, tf);
 #ifdef ASSERT
   unlock->set_dbg_jvms(sync_jvms());
 #endif
   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, in_bytes(Klass::layout_helper_offset()));
   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
 }
 // 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 deoptimize_on_exception) {
   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) ProjNode(allocx, TypeFunc::Control) ) );
   // create memory projection for i_o
   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
   // create a memory projection as for the normal control path
   Node* malloc = _gvn.transform(new (C) 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) ProjNode(allocx, TypeFunc::I_O, false) ) );
   Node* rawoop = _gvn.transform( new (C) 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");
   {
     // 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) 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 'return_size_val', report the the total object size to the caller.
 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
 Node* GraphKit::new_instance(Node* klass_node,
                              Node* extra_slow_test,
                              Node* *return_size_val,
                              bool deoptimize_on_exception) {
   // 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) AndINode(layout_val, bit) );
     if (extra_slow_test != intcon(0)) {
       initial_slow_test = _gvn.transform( new (C) 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) 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(C, AllocateNode::alloc_type(Type::TOP),
                            control(), mem, i_o(),
                            size, klass_node,
                            initial_slow_test);
   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
 }
 //-------------------------------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
                           Node* *return_size_val,
                           bool deoptimize_on_exception) {
   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) CmpINode(layout_val, intcon(layout_con)) );
     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
     { BuildCutout unless(this, bol_lh, PROB_MAX);
       inc_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) CmpUNode( length, intcon( fast_size_limit ) ) );
   Node* initial_slow_test = _gvn.transform( new (C) 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) URShiftINode(layout_val, hss) );
     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
     Node* mask  = intcon(round_mask);
     header_size = _gvn.transform( new(C) 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) 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) LShiftXNode(lengthx, elem_shift) );
   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
   if (round_mask != 0) {
     Node* mask = MakeConX(~round_mask);
     size       = _gvn.transform( new(C) 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(C, AllocateArrayNode::alloc_type(TypeInt::INT),
                                 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, deoptimize_on_exception);
   // 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 only one raw-to-oop cast
     ptr = ptr->in(1);
     if (ptr == NULL) return NULL;
   }
   // Return NULL for allocations with several casts:
   //   j.l.reflect.Array.newInstance(jobject, jint)
   //   Object.clone()
   // to keep more precise type from last cast.
   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) Opaque1Node(C, cont));
   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
   C->add_predicate_opaq(opq);
   {
     PreserveJVMState pjvms(this);
     set_control(iffalse);
     inc_sp(nargs);
     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
   }
   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
   set_control(iftrue);
 }
 //------------------------------add_predicate---------------------------------
 void GraphKit::add_predicate(int nargs) {
   if (UseLoopPredicate) {
     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
   }
   // loop's limit check predicate should be near the loop.
   if (LoopLimitCheck) {
     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
   }
 }
 //----------------------------- store barriers ----------------------------
 #define __ ideal.
 void GraphKit::sync_kit(IdealKit& ideal) {
   set_all_memory(__ merged_memory());
   set_i_o(__ i_o());
   set_control(__ ctrl());
 }
 void GraphKit::final_sync(IdealKit& ideal) {
   // Final sync IdealKit and graphKit.
   sync_kit(ideal);
 }
 // 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;
   }
   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(this, 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;
   Node*   zero = __ ConI(0); // Dirty card value
   BasicType bt = T_BYTE;
   if (UseCondCardMark) {
     // The classic GC reference write barrier is typically implemented
     // as a store into the global card mark table.  Unfortunately
     // unconditional stores can result in false sharing and excessive
     // coherence traffic as well as false transactional aborts.
     // UseCondCardMark enables MP "polite" conditional card mark
     // stores.  In theory we could relax the load from ctrl() to
     // no_ctrl, but that doesn't buy much latitude.
     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
     __ if_then(card_val, BoolTest::ne, zero);
   }
   // Smash zero into card
   if( !UseConcMarkSweepGC ) {
     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::release);
   } else {
     // Specialized path for CM store barrier
     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
   }
   if (UseCondCardMark) {
     __ end_if();
   }
   // Final sync IdealKit and GraphKit.
   final_sync(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");
     // Nothing to be done if pre_val is null.
     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
     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(this, true);
   Node* tls = __ thread(); // ThreadLocalStorage
   Node* no_ctrl = NULL;
   Node* no_base = __ top();
   Node* zero  = __ ConI(0);
   Node* zeroX = __ ConX(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, unlikely); {
     BasicType index_bt = TypeX_X->basic_type();
     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
     if (do_load) {
       // load original value
       // alias_idx correct??
       pre_val = __ load(__ 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, zeroX, likely); {
         // decrement the index
         Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
         // Now get the buffer location we will log the previous value into and store it
         Node *log_addr = __ AddP(no_base, buffer, next_index);
         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
         // update the index
         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
       } __ 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.
   final_sync(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* zeroX = __ ConX(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, zeroX); {
     Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
     Node* log_addr = __ AddP(no_base, buffer, next_index);
     // Order, see storeCM.
     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
   } __ 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(this, true);
   Node* tls = __ thread(); // ThreadLocalStorage
   Node* no_base = __ top();
   float likely  = PROB_LIKELY(0.999);
   float unlikely  = PROB_UNLIKELY(0.999);
   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
   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, TypeX_X, TypeX_X->basic_type(), 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, young_card); {
           sync_kit(ideal);
           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
           insert_mem_bar(Op_MemBarVolatile, oop_store);
           __ sync_kit(this);
           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
           } __ end_if();
         } __ 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.
   final_sync(ideal);
 }
 #undef __
 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
   if (java_lang_String::has_offset_field()) {
     int offset_offset = java_lang_String::offset_offset_in_bytes();
     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
                                                        false, NULL, 0);
     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
     int offset_field_idx = C->get_alias_index(offset_field_type);
     return make_load(ctrl,
                      basic_plus_adr(str, str, offset_offset),
                      TypeInt::INT, T_INT, offset_field_idx, MemNode::unordered);
   } else {
     return intcon(0);
   }
 }
 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
   if (java_lang_String::has_count_field()) {
     int count_offset = java_lang_String::count_offset_in_bytes();
     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
                                                        false, NULL, 0);
     const TypePtr* count_field_type = string_type->add_offset(count_offset);
     int count_field_idx = C->get_alias_index(count_field_type);
     return make_load(ctrl,
                      basic_plus_adr(str, str, count_offset),
                      TypeInt::INT, T_INT, count_field_idx, MemNode::unordered);
   } else {
     return load_array_length(load_String_value(ctrl, str));
   }
 }
 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
   int value_offset = java_lang_String::value_offset_in_bytes();
   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
                                                      false, NULL, 0);
   const TypePtr* value_field_type = string_type->add_offset(value_offset);
   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
   int value_field_idx = C->get_alias_index(value_field_type);
   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
   // String.value field is known to be @Stable.
   if (UseImplicitStableValues) {
     load = cast_array_to_stable(load, value_type);
   }
   return load;
 }
 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
   int offset_offset = java_lang_String::offset_offset_in_bytes();
   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
                                                      false, NULL, 0);
   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
   int offset_field_idx = C->get_alias_index(offset_field_type);
   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
                   value, T_INT, offset_field_idx, MemNode::unordered);
 }
 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
   int value_offset = java_lang_String::value_offset_in_bytes();
   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
                                                      false, NULL, 0);
   const TypePtr* value_field_type = string_type->add_offset(value_offset);
   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
       value, TypeAryPtr::CHARS, T_OBJECT, MemNode::unordered);
 }
 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
   int count_offset = java_lang_String::count_offset_in_bytes();
   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
                                                      false, NULL, 0);
   const TypePtr* count_field_type = string_type->add_offset(count_offset);
   int count_field_idx = C->get_alias_index(count_field_type);
   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
                   value, T_INT, count_field_idx, MemNode::unordered);
 }
 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
   // assumption of CCP analysis.
   return _gvn.transform(new(C) CastPPNode(ary, ary_type->cast_to_stable(true)));
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/graphKit.cpp@c1c199dde5c9 (annotated)

src/share/vm/opto/graphKit.cpp