Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 class FastLockNode;

 class FastUnlockNode;

 class IdealKit;

 class Parse;

 class RootNode;

 //-----------------------------------------------------------------------------

 //----------------------------GraphKit-----------------------------------------

 // Toolkit for building the common sorts of subgraphs.

 // Does not know about bytecode parsing or type-flow results.

 // It is able to create graphs implementing the semantics of most

 // or all bytecodes, so that it can expand intrinsics and calls.

 // It may depend on JVMState structure, but it must not depend

 // on specific bytecode streams.

 class GraphKit : public Phase {

   friend class PreserveJVMState;

  protected:

   ciEnv*            _env;       // Compilation environment

   PhaseGVN         &_gvn;       // Some optimizations while parsing

   SafePointNode*    _map;       // Parser map from JVM to Nodes

   SafePointNode*    _exceptions;// Parser map(s) for exception state(s)

   int               _sp;        // JVM Expression Stack Pointer

   int               _bci;       // JVM Bytecode Pointer

   ciMethod*         _method;    // JVM Current Method

  private:

   SafePointNode*     map_not_null() const {

     assert(_map != NULL, "must call stopped() to test for reset compiler map");

     return _map;

   }

  public:

   GraphKit();                   // empty constructor

   GraphKit(JVMState* jvms);     // the JVM state on which to operate

 #ifdef ASSERT

   ~GraphKit() {

     assert(!has_exceptions(), "user must call transfer_exceptions_into_jvms");

   }

 #endif

   virtual Parse* is_Parse() const { return NULL; }

   ciEnv*        env()           const { return _env; }

   PhaseGVN&     gvn()           const { return _gvn; }

   void record_for_igvn(Node* n) const { C->record_for_igvn(n); }  // delegate to Compile

   // Handy well-known nodes:

   Node*         null()          const { return zerocon(T_OBJECT); }

   Node*         top()           const { return C->top(); }

   RootNode*     root()          const { return C->root(); }

   // Create or find a constant node

   Node* intcon(jint con)        const { return _gvn.intcon(con); }

   Node* longcon(jlong con)      const { return _gvn.longcon(con); }

   Node* makecon(const Type *t)  const { return _gvn.makecon(t); }

   Node* zerocon(BasicType bt)   const { return _gvn.zerocon(bt); }

   // (See also macro MakeConX in type.hpp, which uses intcon or longcon.)

   jint  find_int_con(Node* n, jint value_if_unknown) {

     return _gvn.find_int_con(n, value_if_unknown);

   }

   jlong find_long_con(Node* n, jlong value_if_unknown) {

     return _gvn.find_long_con(n, value_if_unknown);

   }

   // (See also macro find_intptr_t_con in type.hpp, which uses one of these.)

   // JVM State accessors:

   // Parser mapping from JVM indices into Nodes.

   // Low slots are accessed by the StartNode::enum.

   // Then come the locals at StartNode::Parms to StartNode::Parms+max_locals();

   // Then come JVM stack slots.

   // Finally come the monitors, if any.

   // See layout accessors in class JVMState.

   SafePointNode*     map()      const { return _map; }

   bool               has_exceptions() const { return _exceptions != NULL; }

   JVMState*          jvms()     const { return map_not_null()->_jvms; }

   int                sp()       const { return _sp; }

   int                bci()      const { return _bci; }

   Bytecodes::Code    java_bc()  const;

   ciMethod*          method()   const { return _method; }

   void set_jvms(JVMState* jvms)       { set_map(jvms->map());

                                         assert(jvms == this->jvms(), "sanity");

                                         _sp = jvms->sp();

                                         _bci = jvms->bci();

                                         _method = jvms->has_method() ? jvms->method() : NULL; }

   void set_map(SafePointNode* m)      { _map = m; debug_only(verify_map()); }

   void set_sp(int i)                  { assert(i >= 0, "must be non-negative"); _sp = i; }

   void clean_stack(int from_sp); // clear garbage beyond from_sp to top

   void inc_sp(int i)                  { set_sp(sp() + i); }

   void set_bci(int bci)               { _bci = bci; }

   // Make sure jvms has current bci & sp.

   JVMState* sync_jvms()     const;

 #ifdef ASSERT

   // Make sure JVMS has an updated copy of bci and sp.

   // Also sanity-check method, depth, and monitor depth.

   bool jvms_in_sync() const;

   // Make sure the map looks OK.

   void verify_map() const;

   // Make sure a proposed exception state looks OK.

   static void verify_exception_state(SafePointNode* ex_map);

 #endif

   // Clone the existing map state.  (Implements PreserveJVMState.)

   SafePointNode* clone_map();

   // Set the map to a clone of the given one.

   void set_map_clone(SafePointNode* m);

   // Tell if the compilation is failing.

   bool failing() const { return C->failing(); }

   // Set _map to NULL, signalling a stop to further bytecode execution.

   // Preserve the map intact for future use, and return it back to the caller.

   SafePointNode* stop() { SafePointNode* m = map(); set_map(NULL); return m; }

   // Stop, but first smash the map's inputs to NULL, to mark it dead.

   void stop_and_kill_map();

   // Tell if _map is NULL, or control is top.

   bool stopped();

   // Tell if this method or any caller method has exception handlers.

   bool has_ex_handler();

   // Save an exception without blowing stack contents or other JVM state.

   // (The extra pointer is stuck with add_req on the map, beyond the JVMS.)

   static void set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop);

   // Recover a saved exception from its map.

   static Node* saved_ex_oop(SafePointNode* ex_map);

   // Recover a saved exception from its map, and remove it from the map.

   static Node* clear_saved_ex_oop(SafePointNode* ex_map);

 #ifdef ASSERT

   // Recover a saved exception from its map, and remove it from the map.

   static bool has_saved_ex_oop(SafePointNode* ex_map);

 #endif

   // Push an exception in the canonical position for handlers (stack(0)).

   void push_ex_oop(Node* ex_oop) {

     ensure_stack(1);  // ensure room to push the exception

     set_stack(0, ex_oop);

     set_sp(1);

     clean_stack(1);

   }

   // Detach and return an exception state.

   SafePointNode* pop_exception_state() {

     SafePointNode* ex_map = _exceptions;

     if (ex_map != NULL) {

       _exceptions = ex_map->next_exception();

       ex_map->set_next_exception(NULL);

       debug_only(verify_exception_state(ex_map));

     }

     return ex_map;

   }

   // Add an exception, using the given JVM state, without commoning.

   void push_exception_state(SafePointNode* ex_map) {

     debug_only(verify_exception_state(ex_map));

     ex_map->set_next_exception(_exceptions);

     _exceptions = ex_map;

   }

   // Turn the current JVM state into an exception state, appending the ex_oop.

   SafePointNode* make_exception_state(Node* ex_oop);

   // Add an exception, using the given JVM state.

   // Combine all exceptions with a common exception type into a single state.

   // (This is done via combine_exception_states.)

   void add_exception_state(SafePointNode* ex_map);

   // Combine all exceptions of any sort whatever into a single master state.

   SafePointNode* combine_and_pop_all_exception_states() {

     if (_exceptions == NULL)  return NULL;

     SafePointNode* phi_map = pop_exception_state();

     SafePointNode* ex_map;

     while ((ex_map = pop_exception_state()) != NULL) {

       combine_exception_states(ex_map, phi_map);

     }

     return phi_map;

   }

   // Combine the two exception states, building phis as necessary.

   // The second argument is updated to include contributions from the first.

   void combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map);

   // Reset the map to the given state.  If there are any half-finished phis

   // in it (created by combine_exception_states), transform them now.

   // Returns the exception oop.  (Caller must call push_ex_oop if required.)

   Node* use_exception_state(SafePointNode* ex_map);

   // Collect exceptions from a given JVM state into my exception list.

   void add_exception_states_from(JVMState* jvms);

   // Collect all raised exceptions into the current JVM state.

   // Clear the current exception list and map, returns the combined states.

   JVMState* transfer_exceptions_into_jvms();

   // Helper to throw a built-in exception.

   // Range checks take the offending index.

   // Cast and array store checks take the offending class.

   // Others do not take the optional argument.

   // The JVMS must allow the bytecode to be re-executed

   // via an uncommon trap.

   void builtin_throw(Deoptimization::DeoptReason reason, Node* arg = NULL);

   // Helper Functions for adding debug information

   void kill_dead_locals();

 #ifdef ASSERT

   bool dead_locals_are_killed();

 #endif

   // The call may deoptimize.  Supply required JVM state as debug info.

   // If must_throw is true, the call is guaranteed not to return normally.

   void add_safepoint_edges(SafePointNode* call,

                            bool must_throw = false);

   // How many stack inputs does the current BC consume?

   // And, how does the stack change after the bytecode?

   // Returns false if unknown.

   bool compute_stack_effects(int& inputs, int& depth);

   // Add a fixed offset to a pointer

   Node* basic_plus_adr(Node* base, Node* ptr, intptr_t offset) {

     return basic_plus_adr(base, ptr, MakeConX(offset));

   }

   Node* basic_plus_adr(Node* base, intptr_t offset) {

     return basic_plus_adr(base, base, MakeConX(offset));

   }

   // Add a variable offset to a pointer

   Node* basic_plus_adr(Node* base, Node* offset) {

     return basic_plus_adr(base, base, offset);

   }

   Node* basic_plus_adr(Node* base, Node* ptr, Node* offset);

   // Convert between int and long, and size_t.

   // (See macros ConvI2X, etc., in type.hpp for ConvI2X, etc.)

   Node* ConvI2L(Node* offset);

   Node* ConvL2I(Node* offset);

   // Find out the klass of an object.

   Node* load_object_klass(Node* object);

   // Find out the length of an array.

   Node* load_array_length(Node* array);

   // Helper function to do a NULL pointer check or ZERO check based on type.

   Node* null_check_common(Node* value, BasicType type,

                           bool assert_null, Node* *null_control);

   // Throw an exception if a given value is null.

   // Return the value cast to not-null.

   // Be clever about equivalent dominating null checks.

   Node* do_null_check(Node* value, BasicType type) {

     return null_check_common(value, type, false, NULL);

   }

   // Throw an uncommon trap if a given value is __not__ null.

   // Return the value cast to null, and be clever about dominating checks.

   Node* do_null_assert(Node* value, BasicType type) {

     return null_check_common(value, type, true, NULL);

   }

   // Null check oop.  Return null-path control into (*null_control).

   // Return a cast-not-null node which depends on the not-null control.

   // If never_see_null, use an uncommon trap (*null_control sees a top).

   // The cast is not valid along the null path; keep a copy of the original.

   Node* null_check_oop(Node* value, Node* *null_control,

                        bool never_see_null = false);

   // Cast obj to not-null on this path

   Node* cast_not_null(Node* obj, bool do_replace_in_map = true);

   // Replace all occurrences of one node by another.

   void replace_in_map(Node* old, Node* neww);

   void push(Node* n)    { map_not_null(); _map->set_stack(_map->_jvms,_sp++,n); }

   Node* pop()           { map_not_null(); return _map->stack(_map->_jvms,--_sp); }

   Node* peek(int off=0) { map_not_null(); return _map->stack(_map->_jvms, _sp - off - 1); }

   void push_pair(Node* ldval) {

     push(ldval);

     push(top());  // the halfword is merely a placeholder

   }

   void push_pair_local(int i) {

     // longs are stored in locals in "push" order

     push(  local(i+0) );  // the real value

     assert(local(i+1) == top(), "");

     push(top());  // halfword placeholder

   }

   Node* pop_pair() {

     // the second half is pushed last & popped first; it contains exactly nothing

     Node* halfword = pop();

     assert(halfword == top(), "");

     // the long bits are pushed first & popped last:

     return pop();

   }

   void set_pair_local(int i, Node* lval) {

     // longs are stored in locals as a value/half pair (like doubles)

     set_local(i+0, lval);

     set_local(i+1, top());

   }

   // Push the node, which may be zero, one, or two words.

   void push_node(BasicType n_type, Node* n) {

     int n_size = type2size[n_type];

     if      (n_size == 1)  push(      n );  // T_INT, ...

     else if (n_size == 2)  push_pair( n );  // T_DOUBLE, T_LONG

     else                   { assert(n_size == 0, "must be T_VOID"); }

   }

   Node* pop_node(BasicType n_type) {

     int n_size = type2size[n_type];

     if      (n_size == 1)  return pop();

     else if (n_size == 2)  return pop_pair();

     else                   return NULL;

   }

   Node* control()               const { return map_not_null()->control(); }

   Node* i_o()                   const { return map_not_null()->i_o(); }

   Node* returnadr()             const { return map_not_null()->returnadr(); }

   Node* frameptr()              const { return map_not_null()->frameptr(); }

   Node* local(uint idx)         const { map_not_null(); return _map->local(      _map->_jvms, idx); }

   Node* stack(uint idx)         const { map_not_null(); return _map->stack(      _map->_jvms, idx); }

   Node* argument(uint idx)      const { map_not_null(); return _map->argument(   _map->_jvms, idx); }

   Node* monitor_box(uint idx)   const { map_not_null(); return _map->monitor_box(_map->_jvms, idx); }

   Node* monitor_obj(uint idx)   const { map_not_null(); return _map->monitor_obj(_map->_jvms, idx); }

   void set_control  (Node* c)         { map_not_null()->set_control(c); }

   void set_i_o      (Node* c)         { map_not_null()->set_i_o(c); }

   void set_local(uint idx, Node* c)   { map_not_null(); _map->set_local(   _map->_jvms, idx, c); }

   void set_stack(uint idx, Node* c)   { map_not_null(); _map->set_stack(   _map->_jvms, idx, c); }

   void set_argument(uint idx, Node* c){ map_not_null(); _map->set_argument(_map->_jvms, idx, c); }

   void ensure_stack(uint stk_size)    { map_not_null(); _map->ensure_stack(_map->_jvms, stk_size); }

   // Access unaliased memory

   Node* memory(uint alias_idx);

   Node* memory(const TypePtr *tp) { return memory(C->get_alias_index(tp)); }

   Node* memory(Node* adr) { return memory(_gvn.type(adr)->is_ptr()); }

   // Access immutable memory

   Node* immutable_memory() { return C->immutable_memory(); }

   // Set unaliased memory

   void set_memory(Node* c, uint alias_idx) { merged_memory()->set_memory_at(alias_idx, c); }

   void set_memory(Node* c, const TypePtr *tp) { set_memory(c,C->get_alias_index(tp)); }

   void set_memory(Node* c, Node* adr) { set_memory(c,_gvn.type(adr)->is_ptr()); }

   // Get the entire memory state (probably a MergeMemNode), and reset it

   // (The resetting prevents somebody from using the dangling Node pointer.)

   Node* reset_memory();

   // Get the entire memory state, asserted to be a MergeMemNode.

   MergeMemNode* merged_memory() {

     Node* mem = map_not_null()->memory();

     assert(mem->is_MergeMem(), "parse memory is always pre-split");

     return mem->as_MergeMem();

   }

   // Set the entire memory state; produce a new MergeMemNode.

   void set_all_memory(Node* newmem);

   // Create a memory projection from the call, then set_all_memory.

   void set_all_memory_call(Node* call);

   // Create a LoadNode, reading from the parser's memory state.

   // (Note:  require_atomic_access is useful only with T_LONG.)

   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,

                   bool require_atomic_access = false) {

     // This version computes alias_index from bottom_type

     return make_load(ctl, adr, t, bt, adr->bottom_type()->is_ptr(),

                      require_atomic_access);

   }

   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, const TypePtr* adr_type, bool require_atomic_access = false) {

     // This version computes alias_index from an address type

     assert(adr_type != NULL, "use other make_load factory");

     return make_load(ctl, adr, t, bt, C->get_alias_index(adr_type),

                      require_atomic_access);

   }

   // This is the base version which is given an alias index.

   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, int adr_idx, bool require_atomic_access = false);

   // Create & transform a StoreNode and store the effect into the

   // parser's memory state.

   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,

                         const TypePtr* adr_type,

                         bool require_atomic_access = false) {

     // This version computes alias_index from an address type

     assert(adr_type != NULL, "use other store_to_memory factory");

     return store_to_memory(ctl, adr, val, bt,

                            C->get_alias_index(adr_type),

                            require_atomic_access);

   }

   // This is the base version which is given alias index

   // Return the new StoreXNode

   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,

                         int adr_idx,

                         bool require_atomic_access = false);

   // All in one pre-barrier, store, post_barrier

   // Insert a write-barrier'd store.  This is to let generational GC

   // work; we have to flag all oop-stores before the next GC point.

   //

   // It comes in 3 flavors of store to an object, array, or unknown.

   // We use precise card marks for arrays to avoid scanning the entire

   // array. We use imprecise for object. We use precise for unknown

   // since we don't know if we have an array or and object or even

   // where the object starts.

   //

   // If val==NULL, it is taken to be a completely unknown value. QQQ

   Node* store_oop_to_object(Node* ctl,

                             Node* obj,   // containing obj

                             Node* adr,  // actual adress to store val at

                             const TypePtr* adr_type,

                             Node* val,

                             const Type* val_type,

                             BasicType bt);

   Node* store_oop_to_array(Node* ctl,

                            Node* obj,   // containing obj

                            Node* adr,  // actual adress to store val at

                            const TypePtr* adr_type,

                            Node* val,

                            const Type* val_type,

                            BasicType bt);

   // Could be an array or object we don't know at compile time (unsafe ref.)

   Node* store_oop_to_unknown(Node* ctl,

                              Node* obj,   // containing obj

                              Node* adr,  // actual adress to store val at

                              const TypePtr* adr_type,

                              Node* val,

                              const Type* val_type,

                              BasicType bt);

   // For the few case where the barriers need special help

   void pre_barrier(Node* ctl, Node* obj, Node* adr, uint adr_idx,

                    Node* val, const Type* val_type, BasicType bt);

   void post_barrier(Node* ctl, Node* store, Node* obj, Node* adr, uint adr_idx,

                     Node* val, BasicType bt, bool use_precise);

   // Return addressing for an array element.

   Node* array_element_address(Node* ary, Node* idx, BasicType elembt,

                               // Optional constraint on the array size:

                               const TypeInt* sizetype = NULL);

   // Return a load of array element at idx.

   Node* load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype);

   // CMS card-marks have an input from the corresponding oop_store

   void  cms_card_mark(Node* ctl, Node* adr, Node* val, Node* oop_store);

   //---------------- Dtrace support --------------------

   void make_dtrace_method_entry_exit(ciMethod* method, bool is_entry);

   void make_dtrace_method_entry(ciMethod* method) {

     make_dtrace_method_entry_exit(method, true);

   }

   void make_dtrace_method_exit(ciMethod* method) {

     make_dtrace_method_entry_exit(method, false);

   }

   //--------------- stub generation -------------------

  public:

   void gen_stub(address C_function,

                 const char *name,

                 int is_fancy_jump,

                 bool pass_tls,

                 bool return_pc);

   //---------- help for generating calls --------------

   // Do a null check on the receiver, which is in argument(0).

   Node* null_check_receiver(ciMethod* callee) {

     assert(!callee->is_static(), "must be a virtual method");

     int nargs = 1 + callee->signature()->size();

     // Null check on self without removing any arguments.  The argument

     // null check technically happens in the wrong place, which can lead to

     // invalid stack traces when the primitive is inlined into a method

     // which handles NullPointerExceptions.

     Node* receiver = argument(0);

     _sp += nargs;

     receiver = do_null_check(receiver, T_OBJECT);

     _sp -= nargs;

     return receiver;

   }

   // Fill in argument edges for the call from argument(0), argument(1), ...

   // (The next step is to call set_edges_for_java_call.)

   void  set_arguments_for_java_call(CallJavaNode* call);

   // Fill in non-argument edges for the call.

   // Transform the call, and update the basics: control, i_o, memory.

   // (The next step is usually to call set_results_for_java_call.)

   void set_edges_for_java_call(CallJavaNode* call,

                                bool must_throw = false);

   // Finish up a java call that was started by set_edges_for_java_call.

   // Call add_exception on any throw arising from the call.

   // Return the call result (transformed).

   Node* set_results_for_java_call(CallJavaNode* call);

   // Similar to set_edges_for_java_call, but simplified for runtime calls.

   void  set_predefined_output_for_runtime_call(Node* call) {

     set_predefined_output_for_runtime_call(call, NULL, NULL);

   }

   void  set_predefined_output_for_runtime_call(Node* call,

                                                Node* keep_mem,

                                                const TypePtr* hook_mem);

   Node* set_predefined_input_for_runtime_call(SafePointNode* call);

   // helper functions for statistics

   void increment_counter(address counter_addr);   // increment a debug counter

   void increment_counter(Node*   counter_addr);   // increment a debug counter

   // Bail out to the interpreter right now

   // The optional klass is the one causing the trap.

   // The optional reason is debug information written to the compile log.

   // Optional must_throw is the same as with add_safepoint_edges.

   void uncommon_trap(int trap_request,

                      ciKlass* klass = NULL, const char* reason_string = NULL,

                      bool must_throw = false, bool keep_exact_action = false);

   // Shorthand, to avoid saying "Deoptimization::" so many times.

   void uncommon_trap(Deoptimization::DeoptReason reason,

                      Deoptimization::DeoptAction action,

                      ciKlass* klass = NULL, const char* reason_string = NULL,

                      bool must_throw = false, bool keep_exact_action = false) {

     uncommon_trap(Deoptimization::make_trap_request(reason, action),

                   klass, reason_string, must_throw, keep_exact_action);

   }

   // Report if there were too many traps at the current method and bci.

   // Report if a trap was recorded, and/or PerMethodTrapLimit was exceeded.

   // If there is no MDO at all, report no trap unless told to assume it.

   bool too_many_traps(Deoptimization::DeoptReason reason) {

     return C->too_many_traps(method(), bci(), reason);

   }

   // Report if there were too many recompiles at the current method and bci.

   bool too_many_recompiles(Deoptimization::DeoptReason reason) {

     return C->too_many_recompiles(method(), bci(), reason);

   }

   // vanilla/CMS post barrier

   void write_barrier_post(Node *store, Node* obj, Node* adr, Node* val, bool use_precise);

   // Returns the object (if any) which was created the moment before.

   Node* just_allocated_object(Node* current_control);

   static bool use_ReduceInitialCardMarks() {

     return (ReduceInitialCardMarks

             && Universe::heap()->can_elide_tlab_store_barriers());

   }

   // G1 pre/post barriers

   void g1_write_barrier_pre(Node* obj,

                             Node* adr,

                             uint alias_idx,

                             Node* val,

                             const Type* val_type,

                             BasicType bt);

   void g1_write_barrier_post(Node* store,

                              Node* obj,

                              Node* adr,

                              uint alias_idx,

                              Node* val,

                              BasicType bt,

                              bool use_precise);

   // Helper function for g1

   private:

   void g1_mark_card(IdealKit* ideal, Node* card_adr, Node* store,  Node* index, Node* index_adr,

                     Node* buffer, const TypeFunc* tf);

   public:

   // Helper function to round double arguments before a call

   void round_double_arguments(ciMethod* dest_method);

   void round_double_result(ciMethod* dest_method);

   // rounding for strict float precision conformance

   Node* precision_rounding(Node* n);

   // rounding for strict double precision conformance

   Node* dprecision_rounding(Node* n);

   // rounding for non-strict double stores

   Node* dstore_rounding(Node* n);

   // Helper functions for fast/slow path codes

   Node* opt_iff(Node* region, Node* iff);

   Node* make_runtime_call(int flags,

                           const TypeFunc* call_type, address call_addr,

                           const char* call_name,

                           const TypePtr* adr_type, // NULL if no memory effects

                           Node* parm0 = NULL, Node* parm1 = NULL,

                           Node* parm2 = NULL, Node* parm3 = NULL,

                           Node* parm4 = NULL, Node* parm5 = NULL,

                           Node* parm6 = NULL, Node* parm7 = NULL);

   enum {  // flag values for make_runtime_call

     RC_NO_FP = 1,               // CallLeafNoFPNode

     RC_NO_IO = 2,               // do not hook IO edges

     RC_NO_LEAF = 4,             // CallStaticJavaNode

     RC_MUST_THROW = 8,          // flag passed to add_safepoint_edges

     RC_NARROW_MEM = 16,         // input memory is same as output

     RC_UNCOMMON = 32,           // freq. expected to be like uncommon trap

     RC_LEAF = 0                 // null value:  no flags set

   };

   // merge in all memory slices from new_mem, along the given path

   void merge_memory(Node* new_mem, Node* region, int new_path);

   void make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj);

   // Helper functions to build synchronizations

   int next_monitor();

   Node* insert_mem_bar(int opcode, Node* precedent = NULL);

   Node* insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent = NULL);

   // Optional 'precedent' is appended as an extra edge, to force ordering.

   FastLockNode* shared_lock(Node* obj);

   void shared_unlock(Node* box, Node* obj);

   // helper functions for the fast path/slow path idioms

   Node* fast_and_slow(Node* in, const Type *result_type, Node* null_result, IfNode* fast_test, Node* fast_result, address slow_call, const TypeFunc *slow_call_type, Node* slow_arg, klassOop ex_klass, Node* slow_result);

   // Generate an instance-of idiom.  Used by both the instance-of bytecode

   // and the reflective instance-of call.

   Node* gen_instanceof( Node *subobj, Node* superkls );

   // Generate a check-cast idiom.  Used by both the check-cast bytecode

   // and the array-store bytecode

   Node* gen_checkcast( Node *subobj, Node* superkls,

                        Node* *failure_control = NULL );

   // 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 from constant memory taken from the

   // default memory; does not write anything.  It 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* gen_subtype_check(Node* subklass, Node* superklass);

   // Static parse-time type checking logic for gen_subtype_check:

   enum { SSC_always_false, SSC_always_true, SSC_easy_test, SSC_full_test };

   int static_subtype_check(ciKlass* superk, ciKlass* subk);

   // Exact type check used for predicted calls and casts.

   // Rewrites (*casted_receiver) to be casted to the stronger type.

   // (Caller is responsible for doing replace_in_map.)

   Node* type_check_receiver(Node* receiver, ciKlass* klass, float prob,

                             Node* *casted_receiver);

   // implementation of object creation

   Node* set_output_for_allocation(AllocateNode* alloc,

                                   const TypeOopPtr* oop_type,

                                   bool raw_mem_only);

   Node* get_layout_helper(Node* klass_node, jint& constant_value);

   Node* new_instance(Node* klass_node,

                      Node* slow_test = NULL,

                      bool raw_mem_only = false,

                      Node* *return_size_val = NULL);

   Node* new_array(Node* klass_node, Node* count_val,

                   bool raw_mem_only = false, Node* *return_size_val = NULL);

   // Handy for making control flow

   IfNode* create_and_map_if(Node* ctrl, Node* tst, float prob, float cnt) {

     IfNode* iff = new (C, 2) IfNode(ctrl, tst, prob, cnt);// New IfNode's

     _gvn.set_type(iff, iff->Value(&_gvn)); // Value may be known at parse-time

     // Place 'if' on worklist if it will be in graph

     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later

     return iff;

   }

   IfNode* create_and_xform_if(Node* ctrl, Node* tst, float prob, float cnt) {

     IfNode* iff = new (C, 2) IfNode(ctrl, tst, prob, cnt);// New IfNode's

     _gvn.transform(iff);                           // Value may be known at parse-time

     // Place 'if' on worklist if it will be in graph

     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later

     return iff;

   }

 };

 // Helper class to support building of control flow branches. Upon

 // creation the map and sp at bci are cloned and restored upon de-

 // struction. Typical use:

 //

 // { PreserveJVMState pjvms(this);

 //   // code of new branch

 // }

 // // here the JVM state at bci is established

 class PreserveJVMState: public StackObj {

  protected:

   GraphKit*      _kit;

 #ifdef ASSERT

   int            _block;  // PO of current block, if a Parse

   int            _bci;

 #endif

   SafePointNode* _map;

   uint           _sp;

  public:

   PreserveJVMState(GraphKit* kit, bool clone_map = true);

   ~PreserveJVMState();

 };

 // Helper class to build cutouts of the form if (p) ; else {x...}.

 // The code {x...} must not fall through.

 // The kit's main flow of control is set to the "then" continuation of if(p).

 class BuildCutout: public PreserveJVMState {

  public:

   BuildCutout(GraphKit* kit, Node* p, float prob, float cnt = COUNT_UNKNOWN);

   ~BuildCutout();

 };