1 /*
   2  * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OPTO_GRAPHKIT_HPP
  26 #define SHARE_OPTO_GRAPHKIT_HPP
  27 
  28 #include "ci/ciEnv.hpp"
  29 #include "ci/ciMethodData.hpp"
  30 #include "gc/shared/c2/barrierSetC2.hpp"
  31 #include "opto/addnode.hpp"
  32 #include "opto/callnode.hpp"
  33 #include "opto/cfgnode.hpp"
  34 #include "opto/compile.hpp"
  35 #include "opto/divnode.hpp"
  36 #include "opto/mulnode.hpp"
  37 #include "opto/phaseX.hpp"
  38 #include "opto/subnode.hpp"
  39 #include "opto/type.hpp"
  40 #include "runtime/deoptimization.hpp"
  41 
  42 class BarrierSetC2;
  43 class FastLockNode;
  44 class FastUnlockNode;
  45 class IdealKit;
  46 class LibraryCallKit;
  47 class Parse;
  48 class RootNode;
  49 
  50 //-----------------------------------------------------------------------------
  51 //----------------------------GraphKit-----------------------------------------
  52 // Toolkit for building the common sorts of subgraphs.
  53 // Does not know about bytecode parsing or type-flow results.
  54 // It is able to create graphs implementing the semantics of most
  55 // or all bytecodes, so that it can expand intrinsics and calls.
  56 // It may depend on JVMState structure, but it must not depend
  57 // on specific bytecode streams.
  58 class GraphKit : public Phase {
  59   friend class PreserveJVMState;
  60 
  61  protected:
  62   ciEnv*            _env;       // Compilation environment
  63   PhaseGVN         &_gvn;       // Some optimizations while parsing
  64   SafePointNode*    _map;       // Parser map from JVM to Nodes
  65   SafePointNode*    _exceptions;// Parser map(s) for exception state(s)
  66   int               _bci;       // JVM Bytecode Pointer
  67   ciMethod*         _method;    // JVM Current Method
  68   BarrierSetC2*     _barrier_set;
  69 
  70  private:
  71   int               _sp;        // JVM Expression Stack Pointer; don't modify directly!
  72 
  73  private:
  74   SafePointNode*     map_not_null() const {
  75     assert(_map != NULL, "must call stopped() to test for reset compiler map");
  76     return _map;
  77   }
  78 
  79  public:
  80   GraphKit();                   // empty constructor
  81   GraphKit(JVMState* jvms);     // the JVM state on which to operate
  82 
  83 #ifdef ASSERT
  84   ~GraphKit() {
  85     assert(!has_exceptions(), "user must call transfer_exceptions_into_jvms");
  86   }
  87 #endif
  88 
  89   virtual Parse*          is_Parse()          const { return NULL; }
  90   virtual LibraryCallKit* is_LibraryCallKit() const { return NULL; }
  91 
  92   ciEnv*        env()               const { return _env; }
  93   PhaseGVN&     gvn()               const { return _gvn; }
  94   void*         barrier_set_state() const { return C->barrier_set_state(); }
  95 
  96   void record_for_igvn(Node* n) const { C->record_for_igvn(n); }  // delegate to Compile
  97 
  98   // Handy well-known nodes:
  99   Node*         null()          const { return zerocon(T_OBJECT); }
 100   Node*         top()           const { return C->top(); }
 101   RootNode*     root()          const { return C->root(); }
 102 
 103   // Create or find a constant node
 104   Node* intcon(jint con)        const { return _gvn.intcon(con); }
 105   Node* longcon(jlong con)      const { return _gvn.longcon(con); }
 106   Node* makecon(const Type *t)  const { return _gvn.makecon(t); }
 107   Node* zerocon(BasicType bt)   const { return _gvn.zerocon(bt); }
 108   // (See also macro MakeConX in type.hpp, which uses intcon or longcon.)
 109 
 110   jint  find_int_con(Node* n, jint value_if_unknown) {
 111     return _gvn.find_int_con(n, value_if_unknown);
 112   }
 113   jlong find_long_con(Node* n, jlong value_if_unknown) {
 114     return _gvn.find_long_con(n, value_if_unknown);
 115   }
 116   // (See also macro find_intptr_t_con in type.hpp, which uses one of these.)
 117 
 118   // JVM State accessors:
 119   // Parser mapping from JVM indices into Nodes.
 120   // Low slots are accessed by the StartNode::enum.
 121   // Then come the locals at StartNode::Parms to StartNode::Parms+max_locals();
 122   // Then come JVM stack slots.
 123   // Finally come the monitors, if any.
 124   // See layout accessors in class JVMState.
 125 
 126   SafePointNode*     map()      const { return _map; }
 127   bool               has_exceptions() const { return _exceptions != NULL; }
 128   JVMState*          jvms()     const { return map_not_null()->_jvms; }
 129   int                sp()       const { return _sp; }
 130   int                bci()      const { return _bci; }
 131   Bytecodes::Code    java_bc()  const;
 132   ciMethod*          method()   const { return _method; }
 133 
 134   void set_jvms(JVMState* jvms)       { set_map(jvms->map());
 135                                         assert(jvms == this->jvms(), "sanity");
 136                                         _sp = jvms->sp();
 137                                         _bci = jvms->bci();
 138                                         _method = jvms->has_method() ? jvms->method() : NULL; }
 139   void set_map(SafePointNode* m)      { _map = m; debug_only(verify_map()); }
 140   void set_sp(int sp)                 { assert(sp >= 0, "sp must be non-negative: %d", sp); _sp = sp; }
 141   void clean_stack(int from_sp); // clear garbage beyond from_sp to top
 142 
 143   void inc_sp(int i)                  { set_sp(sp() + i); }
 144   void dec_sp(int i)                  { set_sp(sp() - i); }
 145   void set_bci(int bci)               { _bci = bci; }
 146 
 147   // Make sure jvms has current bci & sp.
 148   JVMState* sync_jvms() const;
 149   JVMState* sync_jvms_for_reexecute();
 150 
 151 #ifdef ASSERT
 152   // Make sure JVMS has an updated copy of bci and sp.
 153   // Also sanity-check method, depth, and monitor depth.
 154   bool jvms_in_sync() const;
 155 
 156   // Make sure the map looks OK.
 157   void verify_map() const;
 158 
 159   // Make sure a proposed exception state looks OK.
 160   static void verify_exception_state(SafePointNode* ex_map);
 161 #endif
 162 
 163   // Clone the existing map state.  (Implements PreserveJVMState.)
 164   SafePointNode* clone_map();
 165 
 166   // Set the map to a clone of the given one.
 167   void set_map_clone(SafePointNode* m);
 168 
 169   // Tell if the compilation is failing.
 170   bool failing() const { return C->failing(); }
 171 
 172   // Set _map to NULL, signalling a stop to further bytecode execution.
 173   // Preserve the map intact for future use, and return it back to the caller.
 174   SafePointNode* stop() { SafePointNode* m = map(); set_map(NULL); return m; }
 175 
 176   // Stop, but first smash the map's inputs to NULL, to mark it dead.
 177   void stop_and_kill_map();
 178 
 179   // Tell if _map is NULL, or control is top.
 180   bool stopped();
 181 
 182   // Tell if this method or any caller method has exception handlers.
 183   bool has_ex_handler();
 184 
 185   // Save an exception without blowing stack contents or other JVM state.
 186   // (The extra pointer is stuck with add_req on the map, beyond the JVMS.)
 187   static void set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop);
 188 
 189   // Recover a saved exception from its map.
 190   static Node* saved_ex_oop(SafePointNode* ex_map);
 191 
 192   // Recover a saved exception from its map, and remove it from the map.
 193   static Node* clear_saved_ex_oop(SafePointNode* ex_map);
 194 
 195 #ifdef ASSERT
 196   // Recover a saved exception from its map, and remove it from the map.
 197   static bool has_saved_ex_oop(SafePointNode* ex_map);
 198 #endif
 199 
 200   // Push an exception in the canonical position for handlers (stack(0)).
 201   void push_ex_oop(Node* ex_oop) {
 202     ensure_stack(1);  // ensure room to push the exception
 203     set_stack(0, ex_oop);
 204     set_sp(1);
 205     clean_stack(1);
 206   }
 207 
 208   // Detach and return an exception state.
 209   SafePointNode* pop_exception_state() {
 210     SafePointNode* ex_map = _exceptions;
 211     if (ex_map != NULL) {
 212       _exceptions = ex_map->next_exception();
 213       ex_map->set_next_exception(NULL);
 214       debug_only(verify_exception_state(ex_map));
 215     }
 216     return ex_map;
 217   }
 218 
 219   // Add an exception, using the given JVM state, without commoning.
 220   void push_exception_state(SafePointNode* ex_map) {
 221     debug_only(verify_exception_state(ex_map));
 222     ex_map->set_next_exception(_exceptions);
 223     _exceptions = ex_map;
 224   }
 225 
 226   // Turn the current JVM state into an exception state, appending the ex_oop.
 227   SafePointNode* make_exception_state(Node* ex_oop);
 228 
 229   // Add an exception, using the given JVM state.
 230   // Combine all exceptions with a common exception type into a single state.
 231   // (This is done via combine_exception_states.)
 232   void add_exception_state(SafePointNode* ex_map);
 233 
 234   // Combine all exceptions of any sort whatever into a single master state.
 235   SafePointNode* combine_and_pop_all_exception_states() {
 236     if (_exceptions == NULL)  return NULL;
 237     SafePointNode* phi_map = pop_exception_state();
 238     SafePointNode* ex_map;
 239     while ((ex_map = pop_exception_state()) != NULL) {
 240       combine_exception_states(ex_map, phi_map);
 241     }
 242     return phi_map;
 243   }
 244 
 245   // Combine the two exception states, building phis as necessary.
 246   // The second argument is updated to include contributions from the first.
 247   void combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map);
 248 
 249   // Reset the map to the given state.  If there are any half-finished phis
 250   // in it (created by combine_exception_states), transform them now.
 251   // Returns the exception oop.  (Caller must call push_ex_oop if required.)
 252   Node* use_exception_state(SafePointNode* ex_map);
 253 
 254   // Collect exceptions from a given JVM state into my exception list.
 255   void add_exception_states_from(JVMState* jvms);
 256 
 257   // Collect all raised exceptions into the current JVM state.
 258   // Clear the current exception list and map, returns the combined states.
 259   JVMState* transfer_exceptions_into_jvms();
 260 
 261   // Helper to throw a built-in exception.
 262   // Range checks take the offending index.
 263   // Cast and array store checks take the offending class.
 264   // Others do not take the optional argument.
 265   // The JVMS must allow the bytecode to be re-executed
 266   // via an uncommon trap.
 267   void builtin_throw(Deoptimization::DeoptReason reason, Node* arg = NULL);
 268 
 269   // Helper to check the JavaThread::_should_post_on_exceptions flag
 270   // and branch to an uncommon_trap if it is true (with the specified reason and must_throw)
 271   void uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 272                                                   bool must_throw) ;
 273 
 274   // Helper Functions for adding debug information
 275   void kill_dead_locals();
 276 #ifdef ASSERT
 277   bool dead_locals_are_killed();
 278 #endif
 279   // The call may deoptimize.  Supply required JVM state as debug info.
 280   // If must_throw is true, the call is guaranteed not to return normally.
 281   void add_safepoint_edges(SafePointNode* call,
 282                            bool must_throw = false);
 283 
 284   // How many stack inputs does the current BC consume?
 285   // And, how does the stack change after the bytecode?
 286   // Returns false if unknown.
 287   bool compute_stack_effects(int& inputs, int& depth);
 288 
 289   // Add a fixed offset to a pointer
 290   Node* basic_plus_adr(Node* base, Node* ptr, intptr_t offset) {
 291     return basic_plus_adr(base, ptr, MakeConX(offset));
 292   }
 293   Node* basic_plus_adr(Node* base, intptr_t offset) {
 294     return basic_plus_adr(base, base, MakeConX(offset));
 295   }
 296   // Add a variable offset to a pointer
 297   Node* basic_plus_adr(Node* base, Node* offset) {
 298     return basic_plus_adr(base, base, offset);
 299   }
 300   Node* basic_plus_adr(Node* base, Node* ptr, Node* offset);
 301 
 302 
 303   // Some convenient shortcuts for common nodes
 304   Node* IfTrue(IfNode* iff)                   { return _gvn.transform(new IfTrueNode(iff));      }
 305   Node* IfFalse(IfNode* iff)                  { return _gvn.transform(new IfFalseNode(iff));     }
 306 
 307   Node* AddI(Node* l, Node* r)                { return _gvn.transform(new AddINode(l, r));       }
 308   Node* SubI(Node* l, Node* r)                { return _gvn.transform(new SubINode(l, r));       }
 309   Node* MulI(Node* l, Node* r)                { return _gvn.transform(new MulINode(l, r));       }
 310   Node* DivI(Node* ctl, Node* l, Node* r)     { return _gvn.transform(new DivINode(ctl, l, r));  }
 311 
 312   Node* AndI(Node* l, Node* r)                { return _gvn.transform(new AndINode(l, r));       }
 313   Node* OrI(Node* l, Node* r)                 { return _gvn.transform(new OrINode(l, r));        }
 314   Node* XorI(Node* l, Node* r)                { return _gvn.transform(new XorINode(l, r));       }
 315 
 316   Node* MaxI(Node* l, Node* r)                { return _gvn.transform(new MaxINode(l, r));       }
 317   Node* MinI(Node* l, Node* r)                { return _gvn.transform(new MinINode(l, r));       }
 318 
 319   Node* LShiftI(Node* l, Node* r)             { return _gvn.transform(new LShiftINode(l, r));    }
 320   Node* RShiftI(Node* l, Node* r)             { return _gvn.transform(new RShiftINode(l, r));    }
 321   Node* URShiftI(Node* l, Node* r)            { return _gvn.transform(new URShiftINode(l, r));   }
 322 
 323   Node* CmpI(Node* l, Node* r)                { return _gvn.transform(new CmpINode(l, r));       }
 324   Node* CmpL(Node* l, Node* r)                { return _gvn.transform(new CmpLNode(l, r));       }
 325   Node* CmpP(Node* l, Node* r)                { return _gvn.transform(new CmpPNode(l, r));       }
 326   Node* Bool(Node* cmp, BoolTest::mask relop) { return _gvn.transform(new BoolNode(cmp, relop)); }
 327 
 328   Node* AddP(Node* b, Node* a, Node* o)       { return _gvn.transform(new AddPNode(b, a, o));    }
 329 
 330   // Convert between int and long, and size_t.
 331   // (See macros ConvI2X, etc., in type.hpp for ConvI2X, etc.)
 332   Node* ConvI2L(Node* offset);
 333   Node* ConvI2UL(Node* offset);
 334   Node* ConvL2I(Node* offset);
 335   // Find out the klass of an object.
 336   Node* load_object_klass(Node* object);
 337   // Find out the length of an array.
 338   Node* load_array_length(Node* array);
 339 
 340 
 341   // Helper function to do a NULL pointer check or ZERO check based on type.
 342   // Throw an exception if a given value is null.
 343   // Return the value cast to not-null.
 344   // Be clever about equivalent dominating null checks.
 345   Node* null_check_common(Node* value, BasicType type,
 346                           bool assert_null = false,
 347                           Node* *null_control = NULL,
 348                           bool speculative = false);
 349   Node* null_check(Node* value, BasicType type = T_OBJECT) {
 350     return null_check_common(value, type, false, NULL, !_gvn.type(value)->speculative_maybe_null());
 351   }
 352   Node* null_check_receiver() {
 353     assert(argument(0)->bottom_type()->isa_ptr(), "must be");
 354     return null_check(argument(0));
 355   }
 356   Node* zero_check_int(Node* value) {
 357     assert(value->bottom_type()->basic_type() == T_INT,
 358            "wrong type: %s", type2name(value->bottom_type()->basic_type()));
 359     return null_check_common(value, T_INT);
 360   }
 361   Node* zero_check_long(Node* value) {
 362     assert(value->bottom_type()->basic_type() == T_LONG,
 363            "wrong type: %s", type2name(value->bottom_type()->basic_type()));
 364     return null_check_common(value, T_LONG);
 365   }
 366   // Throw an uncommon trap if a given value is __not__ null.
 367   // Return the value cast to null, and be clever about dominating checks.
 368   Node* null_assert(Node* value, BasicType type = T_OBJECT) {
 369     return null_check_common(value, type, true, NULL, _gvn.type(value)->speculative_always_null());
 370   }
 371 
 372   // Check if value is null and abort if it is
 373   Node* must_be_not_null(Node* value, bool do_replace_in_map);
 374 
 375   // Null check oop.  Return null-path control into (*null_control).
 376   // Return a cast-not-null node which depends on the not-null control.
 377   // If never_see_null, use an uncommon trap (*null_control sees a top).
 378   // The cast is not valid along the null path; keep a copy of the original.
 379   // If safe_for_replace, then we can replace the value with the cast
 380   // in the parsing map (the cast is guaranteed to dominate the map)
 381   Node* null_check_oop(Node* value, Node* *null_control,
 382                        bool never_see_null = false,
 383                        bool safe_for_replace = false,
 384                        bool speculative = false);
 385 
 386   // Check the null_seen bit.
 387   bool seems_never_null(Node* obj, ciProfileData* data, bool& speculating);
 388 
 389   void guard_klass_being_initialized(Node* klass);
 390   void guard_init_thread(Node* klass);
 391 
 392   void clinit_barrier(ciInstanceKlass* ik, ciMethod* context);
 393 
 394   // Check for unique class for receiver at call
 395   ciKlass* profile_has_unique_klass() {
 396     ciCallProfile profile = method()->call_profile_at_bci(bci());
 397     if (profile.count() >= 0 &&         // no cast failures here
 398         profile.has_receiver(0) &&
 399         profile.morphism() == 1) {
 400       return profile.receiver(0);
 401     }
 402     return NULL;
 403   }
 404 
 405   // record type from profiling with the type system
 406   Node* record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind);
 407   void record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc);
 408   void record_profiled_parameters_for_speculation();
 409   void record_profiled_return_for_speculation();
 410   Node* record_profiled_receiver_for_speculation(Node* n);
 411 
 412   // Use the type profile to narrow an object type.
 413   Node* maybe_cast_profiled_receiver(Node* not_null_obj,
 414                                      ciKlass* require_klass,
 415                                      ciKlass* spec,
 416                                      bool safe_for_replace);
 417 
 418   // Cast obj to type and emit guard unless we had too many traps here already
 419   Node* maybe_cast_profiled_obj(Node* obj,
 420                                 ciKlass* type,
 421                                 bool not_null = false);
 422 
 423   // Cast obj to not-null on this path
 424   Node* cast_not_null(Node* obj, bool do_replace_in_map = true);
 425   // Replace all occurrences of one node by another.
 426   void replace_in_map(Node* old, Node* neww);
 427 
 428   void  push(Node* n)     { map_not_null();        _map->set_stack(_map->_jvms,   _sp++        , n); }
 429   Node* pop()             { map_not_null(); return _map->stack(    _map->_jvms, --_sp             ); }
 430   Node* peek(int off = 0) { map_not_null(); return _map->stack(    _map->_jvms,   _sp - off - 1   ); }
 431 
 432   void push_pair(Node* ldval) {
 433     push(ldval);
 434     push(top());  // the halfword is merely a placeholder
 435   }
 436   void push_pair_local(int i) {
 437     // longs are stored in locals in "push" order
 438     push(  local(i+0) );  // the real value
 439     assert(local(i+1) == top(), "");
 440     push(top());  // halfword placeholder
 441   }
 442   Node* pop_pair() {
 443     // the second half is pushed last & popped first; it contains exactly nothing
 444     Node* halfword = pop();
 445     assert(halfword == top(), "");
 446     // the long bits are pushed first & popped last:
 447     return pop();
 448   }
 449   void set_pair_local(int i, Node* lval) {
 450     // longs are stored in locals as a value/half pair (like doubles)
 451     set_local(i+0, lval);
 452     set_local(i+1, top());
 453   }
 454 
 455   // Push the node, which may be zero, one, or two words.
 456   void push_node(BasicType n_type, Node* n) {
 457     int n_size = type2size[n_type];
 458     if      (n_size == 1)  push(      n );  // T_INT, ...
 459     else if (n_size == 2)  push_pair( n );  // T_DOUBLE, T_LONG
 460     else                   { assert(n_size == 0, "must be T_VOID"); }
 461   }
 462 
 463   Node* pop_node(BasicType n_type) {
 464     int n_size = type2size[n_type];
 465     if      (n_size == 1)  return pop();
 466     else if (n_size == 2)  return pop_pair();
 467     else                   return NULL;
 468   }
 469 
 470   Node* control()               const { return map_not_null()->control(); }
 471   Node* i_o()                   const { return map_not_null()->i_o(); }
 472   Node* returnadr()             const { return map_not_null()->returnadr(); }
 473   Node* frameptr()              const { return map_not_null()->frameptr(); }
 474   Node* local(uint idx)         const { map_not_null(); return _map->local(      _map->_jvms, idx); }
 475   Node* stack(uint idx)         const { map_not_null(); return _map->stack(      _map->_jvms, idx); }
 476   Node* argument(uint idx)      const { map_not_null(); return _map->argument(   _map->_jvms, idx); }
 477   Node* monitor_box(uint idx)   const { map_not_null(); return _map->monitor_box(_map->_jvms, idx); }
 478   Node* monitor_obj(uint idx)   const { map_not_null(); return _map->monitor_obj(_map->_jvms, idx); }
 479 
 480   void set_control  (Node* c)         { map_not_null()->set_control(c); }
 481   void set_i_o      (Node* c)         { map_not_null()->set_i_o(c); }
 482   void set_local(uint idx, Node* c)   { map_not_null(); _map->set_local(   _map->_jvms, idx, c); }
 483   void set_stack(uint idx, Node* c)   { map_not_null(); _map->set_stack(   _map->_jvms, idx, c); }
 484   void set_argument(uint idx, Node* c){ map_not_null(); _map->set_argument(_map->_jvms, idx, c); }
 485   void ensure_stack(uint stk_size)    { map_not_null(); _map->ensure_stack(_map->_jvms, stk_size); }
 486 
 487   // Access unaliased memory
 488   Node* memory(uint alias_idx);
 489   Node* memory(const TypePtr *tp) { return memory(C->get_alias_index(tp)); }
 490   Node* memory(Node* adr) { return memory(_gvn.type(adr)->is_ptr()); }
 491 
 492   // Access immutable memory
 493   Node* immutable_memory() { return C->immutable_memory(); }
 494 
 495   // Set unaliased memory
 496   void set_memory(Node* c, uint alias_idx) { merged_memory()->set_memory_at(alias_idx, c); }
 497   void set_memory(Node* c, const TypePtr *tp) { set_memory(c,C->get_alias_index(tp)); }
 498   void set_memory(Node* c, Node* adr) { set_memory(c,_gvn.type(adr)->is_ptr()); }
 499 
 500   // Get the entire memory state (probably a MergeMemNode), and reset it
 501   // (The resetting prevents somebody from using the dangling Node pointer.)
 502   Node* reset_memory();
 503 
 504   // Get the entire memory state, asserted to be a MergeMemNode.
 505   MergeMemNode* merged_memory() {
 506     Node* mem = map_not_null()->memory();
 507     assert(mem->is_MergeMem(), "parse memory is always pre-split");
 508     return mem->as_MergeMem();
 509   }
 510 
 511   // Set the entire memory state; produce a new MergeMemNode.
 512   void set_all_memory(Node* newmem);
 513 
 514   // Create a memory projection from the call, then set_all_memory.
 515   void set_all_memory_call(Node* call, bool separate_io_proj = false);
 516 
 517   // Create a LoadNode, reading from the parser's memory state.
 518   // (Note:  require_atomic_access is useful only with T_LONG.)
 519   //
 520   // We choose the unordered semantics by default because we have
 521   // adapted the `do_put_xxx' and `do_get_xxx' procedures for the case
 522   // of volatile fields.
 523   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
 524                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
 525                   bool require_atomic_access = false, bool unaligned = false,
 526                   bool mismatched = false, bool unsafe = false) {
 527     // This version computes alias_index from bottom_type
 528     return make_load(ctl, adr, t, bt, adr->bottom_type()->is_ptr(),
 529                      mo, control_dependency, require_atomic_access,
 530                      unaligned, mismatched, unsafe);
 531   }
 532   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, const TypePtr* adr_type,
 533                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
 534                   bool require_atomic_access = false, bool unaligned = false,
 535                   bool mismatched = false, bool unsafe = false) {
 536     // This version computes alias_index from an address type
 537     assert(adr_type != NULL, "use other make_load factory");
 538     return make_load(ctl, adr, t, bt, C->get_alias_index(adr_type),
 539                      mo, control_dependency, require_atomic_access,
 540                      unaligned, mismatched, unsafe);
 541   }
 542   // This is the base version which is given an alias index.
 543   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, int adr_idx,
 544                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
 545                   bool require_atomic_access = false, bool unaligned = false,
 546                   bool mismatched = false, bool unsafe = false);
 547 
 548   // Create & transform a StoreNode and store the effect into the
 549   // parser's memory state.
 550   //
 551   // We must ensure that stores of object references will be visible
 552   // only after the object's initialization. So the clients of this
 553   // procedure must indicate that the store requires `release'
 554   // semantics, if the stored value is an object reference that might
 555   // point to a new object and may become externally visible.
 556   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,
 557                         const TypePtr* adr_type,
 558                         MemNode::MemOrd mo,
 559                         bool require_atomic_access = false,
 560                         bool unaligned = false,
 561                         bool mismatched = false,
 562                         bool unsafe = false) {
 563     // This version computes alias_index from an address type
 564     assert(adr_type != NULL, "use other store_to_memory factory");
 565     return store_to_memory(ctl, adr, val, bt,
 566                            C->get_alias_index(adr_type),
 567                            mo, require_atomic_access,
 568                            unaligned, mismatched, unsafe);
 569   }
 570   // This is the base version which is given alias index
 571   // Return the new StoreXNode
 572   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,
 573                         int adr_idx,
 574                         MemNode::MemOrd,
 575                         bool require_atomic_access = false,
 576                         bool unaligned = false,
 577                         bool mismatched = false,
 578                         bool unsafe = false);
 579 
 580   // Perform decorated accesses
 581 
 582   Node* access_store_at(Node* obj,   // containing obj
 583                         Node* adr,   // actual adress to store val at
 584                         const TypePtr* adr_type,
 585                         Node* val,
 586                         const Type* val_type,
 587                         BasicType bt,
 588                         DecoratorSet decorators);
 589 
 590   Node* access_load_at(Node* obj,   // containing obj
 591                        Node* adr,   // actual adress to load val at
 592                        const TypePtr* adr_type,
 593                        const Type* val_type,
 594                        BasicType bt,
 595                        DecoratorSet decorators);
 596 
 597   Node* access_load(Node* adr,   // actual adress to load val at
 598                     const Type* val_type,
 599                     BasicType bt,
 600                     DecoratorSet decorators);
 601 
 602   Node* access_atomic_cmpxchg_val_at(Node* obj,
 603                                      Node* adr,
 604                                      const TypePtr* adr_type,
 605                                      int alias_idx,
 606                                      Node* expected_val,
 607                                      Node* new_val,
 608                                      const Type* value_type,
 609                                      BasicType bt,
 610                                      DecoratorSet decorators);
 611 
 612   Node* access_atomic_cmpxchg_bool_at(Node* obj,
 613                                       Node* adr,
 614                                       const TypePtr* adr_type,
 615                                       int alias_idx,
 616                                       Node* expected_val,
 617                                       Node* new_val,
 618                                       const Type* value_type,
 619                                       BasicType bt,
 620                                       DecoratorSet decorators);
 621 
 622   Node* access_atomic_xchg_at(Node* obj,
 623                               Node* adr,
 624                               const TypePtr* adr_type,
 625                               int alias_idx,
 626                               Node* new_val,
 627                               const Type* value_type,
 628                               BasicType bt,
 629                               DecoratorSet decorators);
 630 
 631   Node* access_atomic_add_at(Node* obj,
 632                              Node* adr,
 633                              const TypePtr* adr_type,
 634                              int alias_idx,
 635                              Node* new_val,
 636                              const Type* value_type,
 637                              BasicType bt,
 638                              DecoratorSet decorators);
 639 
 640   void access_clone(Node* src, Node* dst, Node* size, bool is_array);
 641 
 642   Node* access_resolve(Node* n, DecoratorSet decorators);
 643 
 644   // Return addressing for an array element.
 645   Node* array_element_address(Node* ary, Node* idx, BasicType elembt,
 646                               // Optional constraint on the array size:
 647                               const TypeInt* sizetype = NULL,
 648                               // Optional control dependency (for example, on range check)
 649                               Node* ctrl = NULL);
 650 
 651   // Return a load of array element at idx.
 652   Node* load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype);
 653 
 654   //---------------- Dtrace support --------------------
 655   void make_dtrace_method_entry_exit(ciMethod* method, bool is_entry);
 656   void make_dtrace_method_entry(ciMethod* method) {
 657     make_dtrace_method_entry_exit(method, true);
 658   }
 659   void make_dtrace_method_exit(ciMethod* method) {
 660     make_dtrace_method_entry_exit(method, false);
 661   }
 662 
 663   //--------------- stub generation -------------------
 664  public:
 665   void gen_stub(address C_function,
 666                 const char *name,
 667                 int is_fancy_jump,
 668                 bool pass_tls,
 669                 bool return_pc);
 670 
 671   //---------- help for generating calls --------------
 672 
 673   // Do a null check on the receiver as it would happen before the call to
 674   // callee (with all arguments still on the stack).
 675   Node* null_check_receiver_before_call(ciMethod* callee) {
 676     assert(!callee->is_static(), "must be a virtual method");
 677     // Callsite signature can be different from actual method being called (i.e _linkTo* sites).
 678     // Use callsite signature always.
 679     ciMethod* declared_method = method()->get_method_at_bci(bci());
 680     const int nargs = declared_method->arg_size();
 681     inc_sp(nargs);
 682     Node* n = null_check_receiver();
 683     dec_sp(nargs);
 684     return n;
 685   }
 686 
 687   // Fill in argument edges for the call from argument(0), argument(1), ...
 688   // (The next step is to call set_edges_for_java_call.)
 689   void  set_arguments_for_java_call(CallJavaNode* call);
 690 
 691   // Fill in non-argument edges for the call.
 692   // Transform the call, and update the basics: control, i_o, memory.
 693   // (The next step is usually to call set_results_for_java_call.)
 694   void set_edges_for_java_call(CallJavaNode* call,
 695                                bool must_throw = false, bool separate_io_proj = false);
 696 
 697   // Finish up a java call that was started by set_edges_for_java_call.
 698   // Call add_exception on any throw arising from the call.
 699   // Return the call result (transformed).
 700   Node* set_results_for_java_call(CallJavaNode* call, bool separate_io_proj = false, bool deoptimize = false);
 701 
 702   // Similar to set_edges_for_java_call, but simplified for runtime calls.
 703   void  set_predefined_output_for_runtime_call(Node* call) {
 704     set_predefined_output_for_runtime_call(call, NULL, NULL);
 705   }
 706   void  set_predefined_output_for_runtime_call(Node* call,
 707                                                Node* keep_mem,
 708                                                const TypePtr* hook_mem);
 709   Node* set_predefined_input_for_runtime_call(SafePointNode* call, Node* narrow_mem = NULL);
 710 
 711   // Replace the call with the current state of the kit.  Requires
 712   // that the call was generated with separate io_projs so that
 713   // exceptional control flow can be handled properly.
 714   void replace_call(CallNode* call, Node* result, bool do_replaced_nodes = false);
 715 
 716   // helper functions for statistics
 717   void increment_counter(address counter_addr);   // increment a debug counter
 718   void increment_counter(Node*   counter_addr);   // increment a debug counter
 719 
 720   // Bail out to the interpreter right now
 721   // The optional klass is the one causing the trap.
 722   // The optional reason is debug information written to the compile log.
 723   // Optional must_throw is the same as with add_safepoint_edges.
 724   void uncommon_trap(int trap_request,
 725                      ciKlass* klass = NULL, const char* reason_string = NULL,
 726                      bool must_throw = false, bool keep_exact_action = false);
 727 
 728   // Shorthand, to avoid saying "Deoptimization::" so many times.
 729   void uncommon_trap(Deoptimization::DeoptReason reason,
 730                      Deoptimization::DeoptAction action,
 731                      ciKlass* klass = NULL, const char* reason_string = NULL,
 732                      bool must_throw = false, bool keep_exact_action = false) {
 733     uncommon_trap(Deoptimization::make_trap_request(reason, action),
 734                   klass, reason_string, must_throw, keep_exact_action);
 735   }
 736 
 737   // Bail out to the interpreter and keep exact action (avoid switching to Action_none).
 738   void uncommon_trap_exact(Deoptimization::DeoptReason reason,
 739                            Deoptimization::DeoptAction action,
 740                            ciKlass* klass = NULL, const char* reason_string = NULL,
 741                            bool must_throw = false) {
 742     uncommon_trap(Deoptimization::make_trap_request(reason, action),
 743                   klass, reason_string, must_throw, /*keep_exact_action=*/true);
 744   }
 745 
 746   // SP when bytecode needs to be reexecuted.
 747   virtual int reexecute_sp() { return sp(); }
 748 
 749   // Report if there were too many traps at the current method and bci.
 750   // Report if a trap was recorded, and/or PerMethodTrapLimit was exceeded.
 751   // If there is no MDO at all, report no trap unless told to assume it.
 752   bool too_many_traps(Deoptimization::DeoptReason reason) {
 753     return C->too_many_traps(method(), bci(), reason);
 754   }
 755 
 756   // Report if there were too many recompiles at the current method and bci.
 757   bool too_many_recompiles(Deoptimization::DeoptReason reason) {
 758     return C->too_many_recompiles(method(), bci(), reason);
 759   }
 760 
 761   bool too_many_traps_or_recompiles(Deoptimization::DeoptReason reason) {
 762       return C->too_many_traps_or_recompiles(method(), bci(), reason);
 763   }
 764 
 765   // Returns the object (if any) which was created the moment before.
 766   Node* just_allocated_object(Node* current_control);
 767 
 768   // Sync Ideal and Graph kits.
 769   void sync_kit(IdealKit& ideal);
 770   void final_sync(IdealKit& ideal);
 771 
 772   public:
 773   // Helper function to round double arguments before a call
 774   void round_double_arguments(ciMethod* dest_method);
 775   void round_double_result(ciMethod* dest_method);
 776 
 777   // rounding for strict float precision conformance
 778   Node* precision_rounding(Node* n);
 779 
 780   // rounding for strict double precision conformance
 781   Node* dprecision_rounding(Node* n);
 782 
 783   // rounding for non-strict double stores
 784   Node* dstore_rounding(Node* n);
 785 
 786   // Helper functions for fast/slow path codes
 787   Node* opt_iff(Node* region, Node* iff);
 788   Node* make_runtime_call(int flags,
 789                           const TypeFunc* call_type, address call_addr,
 790                           const char* call_name,
 791                           const TypePtr* adr_type, // NULL if no memory effects
 792                           Node* parm0 = NULL, Node* parm1 = NULL,
 793                           Node* parm2 = NULL, Node* parm3 = NULL,
 794                           Node* parm4 = NULL, Node* parm5 = NULL,
 795                           Node* parm6 = NULL, Node* parm7 = NULL);
 796   enum {  // flag values for make_runtime_call
 797     RC_NO_FP = 1,               // CallLeafNoFPNode
 798     RC_NO_IO = 2,               // do not hook IO edges
 799     RC_NO_LEAF = 4,             // CallStaticJavaNode
 800     RC_MUST_THROW = 8,          // flag passed to add_safepoint_edges
 801     RC_NARROW_MEM = 16,         // input memory is same as output
 802     RC_UNCOMMON = 32,           // freq. expected to be like uncommon trap
 803     RC_LEAF = 0                 // null value:  no flags set
 804   };
 805 
 806   // merge in all memory slices from new_mem, along the given path
 807   void merge_memory(Node* new_mem, Node* region, int new_path);
 808   void make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize = false);
 809 
 810   // Helper functions to build synchronizations
 811   int next_monitor();
 812   Node* insert_mem_bar(int opcode, Node* precedent = NULL);
 813   Node* insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent = NULL);
 814   void insert_store_load_for_barrier();
 815   // Optional 'precedent' is appended as an extra edge, to force ordering.
 816   FastLockNode* shared_lock(Node* obj);
 817   void shared_unlock(Node* box, Node* obj);
 818 
 819   // helper functions for the fast path/slow path idioms
 820   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, Klass* ex_klass, Node* slow_result);
 821 
 822   // Generate an instance-of idiom.  Used by both the instance-of bytecode
 823   // and the reflective instance-of call.
 824   Node* gen_instanceof(Node *subobj, Node* superkls, bool safe_for_replace = false);
 825 
 826   // Generate a check-cast idiom.  Used by both the check-cast bytecode
 827   // and the array-store bytecode
 828   Node* gen_checkcast( Node *subobj, Node* superkls,
 829                        Node* *failure_control = NULL );
 830 
 831   Node* gen_subtype_check(Node* subklass, Node* superklass) {
 832     MergeMemNode* mem = merged_memory();
 833     Node* ctrl = control();
 834     Node* n = Phase::gen_subtype_check(subklass, superklass, &ctrl, mem, &_gvn);
 835     set_control(ctrl);
 836     return n;
 837   }
 838 
 839   // Exact type check used for predicted calls and casts.
 840   // Rewrites (*casted_receiver) to be casted to the stronger type.
 841   // (Caller is responsible for doing replace_in_map.)
 842   Node* type_check_receiver(Node* receiver, ciKlass* klass, float prob,
 843                             Node* *casted_receiver);
 844 
 845   // Inexact type check used for predicted calls.
 846   Node* subtype_check_receiver(Node* receiver, ciKlass* klass,
 847                                Node** casted_receiver);
 848 
 849   // implementation of object creation
 850   Node* set_output_for_allocation(AllocateNode* alloc,
 851                                   const TypeOopPtr* oop_type,
 852                                   bool deoptimize_on_exception=false);
 853   Node* get_layout_helper(Node* klass_node, jint& constant_value);
 854   Node* new_instance(Node* klass_node,
 855                      Node* slow_test = NULL,
 856                      Node* *return_size_val = NULL,
 857                      bool deoptimize_on_exception = false);
 858   Node* new_array(Node* klass_node, Node* count_val, int nargs,
 859                   Node* *return_size_val = NULL,
 860                   bool deoptimize_on_exception = false);
 861 
 862   // java.lang.String helpers
 863   Node* load_String_length(Node* str, bool set_ctrl);
 864   Node* load_String_value(Node* str, bool set_ctrl);
 865   Node* load_String_coder(Node* str, bool set_ctrl);
 866   void store_String_value(Node* str, Node* value);
 867   void store_String_coder(Node* str, Node* value);
 868   Node* capture_memory(const TypePtr* src_type, const TypePtr* dst_type);
 869   Node* compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count);
 870   void inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count);
 871   void inflate_string_slow(Node* src, Node* dst, Node* start, Node* count);
 872 
 873   // Handy for making control flow
 874   IfNode* create_and_map_if(Node* ctrl, Node* tst, float prob, float cnt) {
 875     IfNode* iff = new IfNode(ctrl, tst, prob, cnt);// New IfNode's
 876     _gvn.set_type(iff, iff->Value(&_gvn)); // Value may be known at parse-time
 877     // Place 'if' on worklist if it will be in graph
 878     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later
 879     return iff;
 880   }
 881 
 882   IfNode* create_and_xform_if(Node* ctrl, Node* tst, float prob, float cnt) {
 883     IfNode* iff = new IfNode(ctrl, tst, prob, cnt);// New IfNode's
 884     _gvn.transform(iff);                           // Value may be known at parse-time
 885     // Place 'if' on worklist if it will be in graph
 886     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later
 887     return iff;
 888   }
 889 
 890   // Insert a loop predicate into the graph
 891   void add_predicate(int nargs = 0);
 892   void add_predicate_impl(Deoptimization::DeoptReason reason, int nargs);
 893 
 894   Node* make_constant_from_field(ciField* field, Node* obj);
 895 };
 896 
 897 // Helper class to support building of control flow branches. Upon
 898 // creation the map and sp at bci are cloned and restored upon de-
 899 // struction. Typical use:
 900 //
 901 // { PreserveJVMState pjvms(this);
 902 //   // code of new branch
 903 // }
 904 // // here the JVM state at bci is established
 905 
 906 class PreserveJVMState: public StackObj {
 907  protected:
 908   GraphKit*      _kit;
 909 #ifdef ASSERT
 910   int            _block;  // PO of current block, if a Parse
 911   int            _bci;
 912 #endif
 913   SafePointNode* _map;
 914   uint           _sp;
 915 
 916  public:
 917   PreserveJVMState(GraphKit* kit, bool clone_map = true);
 918   ~PreserveJVMState();
 919 };
 920 
 921 // Helper class to build cutouts of the form if (p) ; else {x...}.
 922 // The code {x...} must not fall through.
 923 // The kit's main flow of control is set to the "then" continuation of if(p).
 924 class BuildCutout: public PreserveJVMState {
 925  public:
 926   BuildCutout(GraphKit* kit, Node* p, float prob, float cnt = COUNT_UNKNOWN);
 927   ~BuildCutout();
 928 };
 929 
 930 // Helper class to preserve the original _reexecute bit and _sp and restore
 931 // them back
 932 class PreserveReexecuteState: public StackObj {
 933  protected:
 934   GraphKit*                 _kit;
 935   uint                      _sp;
 936   JVMState::ReexecuteState  _reexecute;
 937 
 938  public:
 939   PreserveReexecuteState(GraphKit* kit);
 940   ~PreserveReexecuteState();
 941 };
 942 
 943 #endif // SHARE_OPTO_GRAPHKIT_HPP