1 /*
   2  * Copyright (c) 2001, 2015, 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_VM_OPTO_GRAPHKIT_HPP
  26 #define SHARE_VM_OPTO_GRAPHKIT_HPP
  27 
  28 #include "ci/ciEnv.hpp"
  29 #include "ci/ciMethodData.hpp"
  30 #include "opto/addnode.hpp"
  31 #include "opto/callnode.hpp"
  32 #include "opto/cfgnode.hpp"
  33 #include "opto/compile.hpp"
  34 #include "opto/divnode.hpp"
  35 #include "opto/mulnode.hpp"
  36 #include "opto/phaseX.hpp"
  37 #include "opto/subnode.hpp"
  38 #include "opto/type.hpp"
  39 #include "runtime/deoptimization.hpp"
  40 
  41 class FastLockNode;
  42 class FastUnlockNode;
  43 class IdealKit;
  44 class LibraryCallKit;
  45 class Parse;
  46 class RootNode;
  47 
  48 //-----------------------------------------------------------------------------
  49 //----------------------------GraphKit-----------------------------------------
  50 // Toolkit for building the common sorts of subgraphs.
  51 // Does not know about bytecode parsing or type-flow results.
  52 // It is able to create graphs implementing the semantics of most
  53 // or all bytecodes, so that it can expand intrinsics and calls.
  54 // It may depend on JVMState structure, but it must not depend
  55 // on specific bytecode streams.
  56 class GraphKit : public Phase {
  57   friend class PreserveJVMState;
  58 
  59  protected:
  60   ciEnv*            _env;       // Compilation environment
  61   PhaseGVN         &_gvn;       // Some optimizations while parsing
  62   SafePointNode*    _map;       // Parser map from JVM to Nodes
  63   SafePointNode*    _exceptions;// Parser map(s) for exception state(s)
  64   int               _bci;       // JVM Bytecode Pointer
  65   ciMethod*         _method;    // JVM Current Method
  66 #ifdef ASSERT
  67   uint              _worklist_size;
  68 #endif
  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, PhaseGVN* gvn = NULL);     // 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     // During incremental inlining, the Node_Array of the C->for_igvn() worklist and the IGVN
  87     // worklist are shared but the _in_worklist VectorSet is not. To avoid inconsistencies,
  88     // we should not add nodes to the _for_igvn worklist when using IGVN for the GraphKit.
  89     assert((_gvn.is_IterGVN() == NULL) || (_gvn.C->for_igvn()->size() == _worklist_size),
  90            "GraphKit should not modify _for_igvn worklist after parsing");
  91   }
  92 #endif
  93 
  94   virtual Parse*          is_Parse()          const { return NULL; }
  95   virtual LibraryCallKit* is_LibraryCallKit() const { return NULL; }
  96 
  97   ciEnv*        env()           const { return _env; }
  98   PhaseGVN&     gvn()           const { return _gvn; }
  99 
 100   void record_for_igvn(Node* n) const { _gvn.record_for_igvn(n); }
 101 
 102   // Handy well-known nodes:
 103   Node*         null()          const { return zerocon(T_OBJECT); }
 104   Node*         top()           const { return C->top(); }
 105   RootNode*     root()          const { return C->root(); }
 106 
 107   // Create or find a constant node
 108   Node* intcon(jint con)        const { return _gvn.intcon(con); }
 109   Node* longcon(jlong con)      const { return _gvn.longcon(con); }
 110   Node* makecon(const Type *t)  const { return _gvn.makecon(t); }
 111   Node* zerocon(BasicType bt)   const { return _gvn.zerocon(bt); }
 112   // (See also macro MakeConX in type.hpp, which uses intcon or longcon.)
 113 
 114   // Helper for byte_map_base
 115   Node* byte_map_base_node();
 116 
 117   jint  find_int_con(Node* n, jint value_if_unknown) {
 118     return _gvn.find_int_con(n, value_if_unknown);
 119   }
 120   jlong find_long_con(Node* n, jlong value_if_unknown) {
 121     return _gvn.find_long_con(n, value_if_unknown);
 122   }
 123   // (See also macro find_intptr_t_con in type.hpp, which uses one of these.)
 124 
 125   // JVM State accessors:
 126   // Parser mapping from JVM indices into Nodes.
 127   // Low slots are accessed by the StartNode::enum.
 128   // Then come the locals at StartNode::Parms to StartNode::Parms+max_locals();
 129   // Then come JVM stack slots.
 130   // Finally come the monitors, if any.
 131   // See layout accessors in class JVMState.
 132 
 133   SafePointNode*     map()      const { return _map; }
 134   bool               has_exceptions() const { return _exceptions != NULL; }
 135   JVMState*          jvms()     const { return map_not_null()->_jvms; }
 136   int                sp()       const { return _sp; }
 137   int                bci()      const { return _bci; }
 138   Bytecodes::Code    java_bc()  const;
 139   ciMethod*          method()   const { return _method; }
 140 
 141   void set_jvms(JVMState* jvms)       { set_map(jvms->map());
 142                                         assert(jvms == this->jvms(), "sanity");
 143                                         _sp = jvms->sp();
 144                                         _bci = jvms->bci();
 145                                         _method = jvms->has_method() ? jvms->method() : NULL; }
 146   void set_map(SafePointNode* m)      { _map = m; debug_only(verify_map()); }
 147   void set_sp(int sp)                 { assert(sp >= 0, "sp must be non-negative: %d", sp); _sp = sp; }
 148   void clean_stack(int from_sp); // clear garbage beyond from_sp to top
 149 
 150   void inc_sp(int i)                  { set_sp(sp() + i); }
 151   void dec_sp(int i)                  { set_sp(sp() - i); }
 152   void set_bci(int bci)               { _bci = bci; }
 153 
 154   // Make sure jvms has current bci & sp.
 155   JVMState* sync_jvms() const;
 156   JVMState* sync_jvms_for_reexecute();
 157 
 158 #ifdef ASSERT
 159   // Make sure JVMS has an updated copy of bci and sp.
 160   // Also sanity-check method, depth, and monitor depth.
 161   bool jvms_in_sync() const;
 162 
 163   // Make sure the map looks OK.
 164   void verify_map() const;
 165 
 166   // Make sure a proposed exception state looks OK.
 167   static void verify_exception_state(SafePointNode* ex_map);
 168 #endif
 169 
 170   // Clone the existing map state.  (Implements PreserveJVMState.)
 171   SafePointNode* clone_map();
 172 
 173   // Set the map to a clone of the given one.
 174   void set_map_clone(SafePointNode* m);
 175 
 176   // Tell if the compilation is failing.
 177   bool failing() const { return C->failing(); }
 178 
 179   // Set _map to NULL, signalling a stop to further bytecode execution.
 180   // Preserve the map intact for future use, and return it back to the caller.
 181   SafePointNode* stop() { SafePointNode* m = map(); set_map(NULL); return m; }
 182 
 183   // Stop, but first smash the map's inputs to NULL, to mark it dead.
 184   void stop_and_kill_map();
 185 
 186   // Tell if _map is NULL, or control is top.
 187   bool stopped();
 188 
 189   // Tell if this method or any caller method has exception handlers.
 190   bool has_ex_handler();
 191 
 192   // Save an exception without blowing stack contents or other JVM state.
 193   // (The extra pointer is stuck with add_req on the map, beyond the JVMS.)
 194   static void set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop);
 195 
 196   // Recover a saved exception from its map.
 197   static Node* saved_ex_oop(SafePointNode* ex_map);
 198 
 199   // Recover a saved exception from its map, and remove it from the map.
 200   static Node* clear_saved_ex_oop(SafePointNode* ex_map);
 201 
 202 #ifdef ASSERT
 203   // Recover a saved exception from its map, and remove it from the map.
 204   static bool has_saved_ex_oop(SafePointNode* ex_map);
 205 #endif
 206 
 207   // Push an exception in the canonical position for handlers (stack(0)).
 208   void push_ex_oop(Node* ex_oop) {
 209     ensure_stack(1);  // ensure room to push the exception
 210     set_stack(0, ex_oop);
 211     set_sp(1);
 212     clean_stack(1);
 213   }
 214 
 215   // Detach and return an exception state.
 216   SafePointNode* pop_exception_state() {
 217     SafePointNode* ex_map = _exceptions;
 218     if (ex_map != NULL) {
 219       _exceptions = ex_map->next_exception();
 220       ex_map->set_next_exception(NULL);
 221       debug_only(verify_exception_state(ex_map));
 222     }
 223     return ex_map;
 224   }
 225 
 226   // Add an exception, using the given JVM state, without commoning.
 227   void push_exception_state(SafePointNode* ex_map) {
 228     debug_only(verify_exception_state(ex_map));
 229     ex_map->set_next_exception(_exceptions);
 230     _exceptions = ex_map;
 231   }
 232 
 233   // Turn the current JVM state into an exception state, appending the ex_oop.
 234   SafePointNode* make_exception_state(Node* ex_oop);
 235 
 236   // Add an exception, using the given JVM state.
 237   // Combine all exceptions with a common exception type into a single state.
 238   // (This is done via combine_exception_states.)
 239   void add_exception_state(SafePointNode* ex_map);
 240 
 241   // Combine all exceptions of any sort whatever into a single master state.
 242   SafePointNode* combine_and_pop_all_exception_states() {
 243     if (_exceptions == NULL)  return NULL;
 244     SafePointNode* phi_map = pop_exception_state();
 245     SafePointNode* ex_map;
 246     while ((ex_map = pop_exception_state()) != NULL) {
 247       combine_exception_states(ex_map, phi_map);
 248     }
 249     return phi_map;
 250   }
 251 
 252   // Combine the two exception states, building phis as necessary.
 253   // The second argument is updated to include contributions from the first.
 254   void combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map);
 255 
 256   // Reset the map to the given state.  If there are any half-finished phis
 257   // in it (created by combine_exception_states), transform them now.
 258   // Returns the exception oop.  (Caller must call push_ex_oop if required.)
 259   Node* use_exception_state(SafePointNode* ex_map);
 260 
 261   // Collect exceptions from a given JVM state into my exception list.
 262   void add_exception_states_from(JVMState* jvms);
 263 
 264   // Collect all raised exceptions into the current JVM state.
 265   // Clear the current exception list and map, returns the combined states.
 266   JVMState* transfer_exceptions_into_jvms();
 267 
 268   // Helper to throw a built-in exception.
 269   // Range checks take the offending index.
 270   // Cast and array store checks take the offending class.
 271   // Others do not take the optional argument.
 272   // The JVMS must allow the bytecode to be re-executed
 273   // via an uncommon trap.
 274   void builtin_throw(Deoptimization::DeoptReason reason, Node* arg = NULL);
 275 
 276   // Helper to check the JavaThread::_should_post_on_exceptions flag
 277   // and branch to an uncommon_trap if it is true (with the specified reason and must_throw)
 278   void uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 279                                                   bool must_throw) ;
 280 
 281   // Helper Functions for adding debug information
 282   void kill_dead_locals();
 283 #ifdef ASSERT
 284   bool dead_locals_are_killed();
 285 #endif
 286   // The call may deoptimize.  Supply required JVM state as debug info.
 287   // If must_throw is true, the call is guaranteed not to return normally.
 288   void add_safepoint_edges(SafePointNode* call,
 289                            bool must_throw = false);
 290 
 291   // How many stack inputs does the current BC consume?
 292   // And, how does the stack change after the bytecode?
 293   // Returns false if unknown.
 294   bool compute_stack_effects(int& inputs, int& depth);
 295 
 296   // Add a fixed offset to a pointer
 297   Node* basic_plus_adr(Node* base, Node* ptr, intptr_t offset) {
 298     return basic_plus_adr(base, ptr, MakeConX(offset));
 299   }
 300   Node* basic_plus_adr(Node* base, intptr_t offset) {
 301     return basic_plus_adr(base, base, MakeConX(offset));
 302   }
 303   // Add a variable offset to a pointer
 304   Node* basic_plus_adr(Node* base, Node* offset) {
 305     return basic_plus_adr(base, base, offset);
 306   }
 307   Node* basic_plus_adr(Node* base, Node* ptr, Node* offset);
 308 
 309 
 310   // Some convenient shortcuts for common nodes
 311   Node* IfTrue(IfNode* iff)                   { return _gvn.transform(new IfTrueNode(iff));      }
 312   Node* IfFalse(IfNode* iff)                  { return _gvn.transform(new IfFalseNode(iff));     }
 313 
 314   Node* AddI(Node* l, Node* r)                { return _gvn.transform(new AddINode(l, r));       }
 315   Node* SubI(Node* l, Node* r)                { return _gvn.transform(new SubINode(l, r));       }
 316   Node* MulI(Node* l, Node* r)                { return _gvn.transform(new MulINode(l, r));       }
 317   Node* DivI(Node* ctl, Node* l, Node* r)     { return _gvn.transform(new DivINode(ctl, l, r));  }
 318 
 319   Node* AndI(Node* l, Node* r)                { return _gvn.transform(new AndINode(l, r));       }
 320   Node* OrI(Node* l, Node* r)                 { return _gvn.transform(new OrINode(l, r));        }
 321   Node* XorI(Node* l, Node* r)                { return _gvn.transform(new XorINode(l, r));       }
 322 
 323   Node* MaxI(Node* l, Node* r)                { return _gvn.transform(new MaxINode(l, r));       }
 324   Node* MinI(Node* l, Node* r)                { return _gvn.transform(new MinINode(l, r));       }
 325 
 326   Node* LShiftI(Node* l, Node* r)             { return _gvn.transform(new LShiftINode(l, r));    }
 327   Node* RShiftI(Node* l, Node* r)             { return _gvn.transform(new RShiftINode(l, r));    }
 328   Node* URShiftI(Node* l, Node* r)            { return _gvn.transform(new URShiftINode(l, r));   }
 329 
 330   Node* CmpI(Node* l, Node* r)                { return _gvn.transform(new CmpINode(l, r));       }
 331   Node* CmpL(Node* l, Node* r)                { return _gvn.transform(new CmpLNode(l, r));       }
 332   Node* CmpP(Node* l, Node* r)                { return _gvn.transform(new CmpPNode(l, r));       }
 333   Node* Bool(Node* cmp, BoolTest::mask relop) { return _gvn.transform(new BoolNode(cmp, relop)); }
 334 
 335   Node* AddP(Node* b, Node* a, Node* o)       { return _gvn.transform(new AddPNode(b, a, o));    }
 336 
 337   // Convert between int and long, and size_t.
 338   // (See macros ConvI2X, etc., in type.hpp for ConvI2X, etc.)
 339   Node* ConvI2L(Node* offset);
 340   Node* ConvI2UL(Node* offset);
 341   Node* ConvL2I(Node* offset);
 342   // Find out the klass of an object.
 343   Node* load_object_klass(Node* object);
 344   // Find out the length of an array.
 345   Node* load_array_length(Node* array);
 346 
 347 
 348   // Helper function to do a NULL pointer check or ZERO check based on type.
 349   // Throw an exception if a given value is null.
 350   // Return the value cast to not-null.
 351   // Be clever about equivalent dominating null checks.
 352   Node* null_check_common(Node* value, BasicType type,
 353                           bool assert_null = false,
 354                           Node* *null_control = NULL,
 355                           bool speculative = false);
 356   Node* null_check(Node* value, BasicType type = T_OBJECT) {
 357     return null_check_common(value, type, false, NULL, !_gvn.type(value)->speculative_maybe_null());
 358   }
 359   Node* null_check_receiver() {
 360     assert(argument(0)->bottom_type()->isa_ptr(), "must be");
 361     return null_check(argument(0));
 362   }
 363   Node* zero_check_int(Node* value) {
 364     assert(value->bottom_type()->basic_type() == T_INT,
 365            "wrong type: %s", type2name(value->bottom_type()->basic_type()));
 366     return null_check_common(value, T_INT);
 367   }
 368   Node* zero_check_long(Node* value) {
 369     assert(value->bottom_type()->basic_type() == T_LONG,
 370            "wrong type: %s", type2name(value->bottom_type()->basic_type()));
 371     return null_check_common(value, T_LONG);
 372   }
 373   // Throw an uncommon trap if a given value is __not__ null.
 374   // Return the value cast to null, and be clever about dominating checks.
 375   Node* null_assert(Node* value, BasicType type = T_OBJECT) {
 376     return null_check_common(value, type, true, NULL, _gvn.type(value)->speculative_always_null());
 377   }
 378 
 379   // Check if value is null and abort if it is
 380   Node* must_be_not_null(Node* value, bool do_replace_in_map);
 381 
 382   // Null check oop.  Return null-path control into (*null_control).
 383   // Return a cast-not-null node which depends on the not-null control.
 384   // If never_see_null, use an uncommon trap (*null_control sees a top).
 385   // The cast is not valid along the null path; keep a copy of the original.
 386   // If safe_for_replace, then we can replace the value with the cast
 387   // in the parsing map (the cast is guaranteed to dominate the map)
 388   Node* null_check_oop(Node* value, Node* *null_control,
 389                        bool never_see_null = false,
 390                        bool safe_for_replace = false,
 391                        bool speculative = false);
 392 
 393   // Check the null_seen bit.
 394   bool seems_never_null(Node* obj, ciProfileData* data, bool& speculating);
 395 
 396   // Check for unique class for receiver at call
 397   ciKlass* profile_has_unique_klass() {
 398     ciCallProfile profile = method()->call_profile_at_bci(bci());
 399     if (profile.count() >= 0 &&         // no cast failures here
 400         profile.has_receiver(0) &&
 401         profile.morphism() == 1) {
 402       return profile.receiver(0);
 403     }
 404     return NULL;
 405   }
 406 
 407   // record type from profiling with the type system
 408   Node* record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind);
 409   void record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc);
 410   void record_profiled_parameters_for_speculation();
 411   void record_profiled_return_for_speculation();
 412   Node* record_profiled_receiver_for_speculation(Node* n);
 413 
 414   // Use the type profile to narrow an object type.
 415   Node* maybe_cast_profiled_receiver(Node* not_null_obj,
 416                                      ciKlass* require_klass,
 417                                      ciKlass* spec,
 418                                      bool safe_for_replace);
 419 
 420   // Cast obj to type and emit guard unless we had too many traps here already
 421   Node* maybe_cast_profiled_obj(Node* obj,
 422                                 ciKlass* type,
 423                                 bool not_null = false);
 424 
 425   // Cast obj to not-null on this path
 426   Node* cast_not_null(Node* obj, bool do_replace_in_map = true);
 427   // Replace all occurrences of one node by another.
 428   void replace_in_map(Node* old, Node* neww);
 429 
 430   void  push(Node* n)     { map_not_null();        _map->set_stack(_map->_jvms,   _sp++        , n); }
 431   Node* pop()             { map_not_null(); return _map->stack(    _map->_jvms, --_sp             ); }
 432   Node* peek(int off = 0) { map_not_null(); return _map->stack(    _map->_jvms,   _sp - off - 1   ); }
 433 
 434   void push_pair(Node* ldval) {
 435     push(ldval);
 436     push(top());  // the halfword is merely a placeholder
 437   }
 438   void push_pair_local(int i) {
 439     // longs are stored in locals in "push" order
 440     push(  local(i+0) );  // the real value
 441     assert(local(i+1) == top(), "");
 442     push(top());  // halfword placeholder
 443   }
 444   Node* pop_pair() {
 445     // the second half is pushed last & popped first; it contains exactly nothing
 446     Node* halfword = pop();
 447     assert(halfword == top(), "");
 448     // the long bits are pushed first & popped last:
 449     return pop();
 450   }
 451   void set_pair_local(int i, Node* lval) {
 452     // longs are stored in locals as a value/half pair (like doubles)
 453     set_local(i+0, lval);
 454     set_local(i+1, top());
 455   }
 456 
 457   // Push the node, which may be zero, one, or two words.
 458   void push_node(BasicType n_type, Node* n) {
 459     int n_size = type2size[n_type];
 460     if      (n_size == 1)  push(      n );  // T_INT, ...
 461     else if (n_size == 2)  push_pair( n );  // T_DOUBLE, T_LONG
 462     else                   { assert(n_size == 0, "must be T_VOID"); }
 463   }
 464 
 465   Node* pop_node(BasicType n_type) {
 466     int n_size = type2size[n_type];
 467     if      (n_size == 1)  return pop();
 468     else if (n_size == 2)  return pop_pair();
 469     else                   return NULL;
 470   }
 471 
 472   Node* control()               const { return map_not_null()->control(); }
 473   Node* i_o()                   const { return map_not_null()->i_o(); }
 474   Node* returnadr()             const { return map_not_null()->returnadr(); }
 475   Node* frameptr()              const { return map_not_null()->frameptr(); }
 476   Node* local(uint idx)         const { map_not_null(); return _map->local(      _map->_jvms, idx); }
 477   Node* stack(uint idx)         const { map_not_null(); return _map->stack(      _map->_jvms, idx); }
 478   Node* argument(uint idx)      const { map_not_null(); return _map->argument(   _map->_jvms, idx); }
 479   Node* monitor_box(uint idx)   const { map_not_null(); return _map->monitor_box(_map->_jvms, idx); }
 480   Node* monitor_obj(uint idx)   const { map_not_null(); return _map->monitor_obj(_map->_jvms, idx); }
 481 
 482   void set_control  (Node* c)         { map_not_null()->set_control(c); }
 483   void set_i_o      (Node* c)         { map_not_null()->set_i_o(c); }
 484   void set_local(uint idx, Node* c)   { map_not_null(); _map->set_local(   _map->_jvms, idx, c); }
 485   void set_stack(uint idx, Node* c)   { map_not_null(); _map->set_stack(   _map->_jvms, idx, c); }
 486   void set_argument(uint idx, Node* c){ map_not_null(); _map->set_argument(_map->_jvms, idx, c); }
 487   void ensure_stack(uint stk_size)    { map_not_null(); _map->ensure_stack(_map->_jvms, stk_size); }
 488 
 489   // Access unaliased memory
 490   Node* memory(uint alias_idx);
 491   Node* memory(const TypePtr *tp) { return memory(C->get_alias_index(tp)); }
 492   Node* memory(Node* adr) { return memory(_gvn.type(adr)->is_ptr()); }
 493 
 494   // Access immutable memory
 495   Node* immutable_memory() { return C->immutable_memory(); }
 496 
 497   // Set unaliased memory
 498   void set_memory(Node* c, uint alias_idx) { merged_memory()->set_memory_at(alias_idx, c); }
 499   void set_memory(Node* c, const TypePtr *tp) { set_memory(c,C->get_alias_index(tp)); }
 500   void set_memory(Node* c, Node* adr) { set_memory(c,_gvn.type(adr)->is_ptr()); }
 501 
 502   // Get the entire memory state (probably a MergeMemNode), and reset it
 503   // (The resetting prevents somebody from using the dangling Node pointer.)
 504   Node* reset_memory();
 505 
 506   // Get the entire memory state, asserted to be a MergeMemNode.
 507   MergeMemNode* merged_memory() {
 508     Node* mem = map_not_null()->memory();
 509     assert(mem->is_MergeMem(), "parse memory is always pre-split");
 510     return mem->as_MergeMem();
 511   }
 512 
 513   // Set the entire memory state; produce a new MergeMemNode.
 514   void set_all_memory(Node* newmem);
 515 
 516   // Create a memory projection from the call, then set_all_memory.
 517   void set_all_memory_call(Node* call, bool separate_io_proj = false);
 518 
 519   // Create a LoadNode, reading from the parser's memory state.
 520   // (Note:  require_atomic_access is useful only with T_LONG.)
 521   //
 522   // We choose the unordered semantics by default because we have
 523   // adapted the `do_put_xxx' and `do_get_xxx' procedures for the case
 524   // of volatile fields.
 525   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
 526                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
 527                   bool require_atomic_access = false, bool unaligned = false,
 528                   bool mismatched = false) {
 529     // This version computes alias_index from bottom_type
 530     return make_load(ctl, adr, t, bt, adr->bottom_type()->is_ptr(),
 531                      mo, control_dependency, require_atomic_access,
 532                      unaligned, mismatched);
 533   }
 534   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, const TypePtr* adr_type,
 535                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
 536                   bool require_atomic_access = false, bool unaligned = false,
 537                   bool mismatched = false) {
 538     // This version computes alias_index from an address type
 539     assert(adr_type != NULL, "use other make_load factory");
 540     return make_load(ctl, adr, t, bt, C->get_alias_index(adr_type),
 541                      mo, control_dependency, require_atomic_access,
 542                      unaligned, mismatched);
 543   }
 544   // This is the base version which is given an alias index.
 545   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, int adr_idx,
 546                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
 547                   bool require_atomic_access = false, bool unaligned = false,
 548                   bool mismatched = false);
 549 
 550   // Create & transform a StoreNode and store the effect into the
 551   // parser's memory state.
 552   //
 553   // We must ensure that stores of object references will be visible
 554   // only after the object's initialization. So the clients of this
 555   // procedure must indicate that the store requires `release'
 556   // semantics, if the stored value is an object reference that might
 557   // point to a new object and may become externally visible.
 558   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,
 559                         const TypePtr* adr_type,
 560                         MemNode::MemOrd mo,
 561                         bool require_atomic_access = false,
 562                         bool unaligned = false,
 563                         bool mismatched = false) {
 564     // This version computes alias_index from an address type
 565     assert(adr_type != NULL, "use other store_to_memory factory");
 566     return store_to_memory(ctl, adr, val, bt,
 567                            C->get_alias_index(adr_type),
 568                            mo, require_atomic_access,
 569                            unaligned, mismatched);
 570   }
 571   // This is the base version which is given alias index
 572   // Return the new StoreXNode
 573   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,
 574                         int adr_idx,
 575                         MemNode::MemOrd,
 576                         bool require_atomic_access = false,
 577                         bool unaligned = false,
 578                         bool mismatched = false);
 579 
 580 
 581   // All in one pre-barrier, store, post_barrier
 582   // Insert a write-barrier'd store.  This is to let generational GC
 583   // work; we have to flag all oop-stores before the next GC point.
 584   //
 585   // It comes in 3 flavors of store to an object, array, or unknown.
 586   // We use precise card marks for arrays to avoid scanning the entire
 587   // array. We use imprecise for object. We use precise for unknown
 588   // since we don't know if we have an array or and object or even
 589   // where the object starts.
 590   //
 591   // If val==NULL, it is taken to be a completely unknown value. QQQ
 592 
 593   Node* store_oop(Node* ctl,
 594                   Node* obj,   // containing obj
 595                   Node* adr,   // actual adress to store val at
 596                   const TypePtr* adr_type,
 597                   Node* val,
 598                   const TypeOopPtr* val_type,
 599                   BasicType bt,
 600                   bool use_precise,
 601                   MemNode::MemOrd mo,
 602                   bool mismatched = false);
 603 
 604   Node* store_oop_to_object(Node* ctl,
 605                             Node* obj,   // containing obj
 606                             Node* adr,   // actual adress to store val at
 607                             const TypePtr* adr_type,
 608                             Node* val,
 609                             const TypeOopPtr* val_type,
 610                             BasicType bt,
 611                             MemNode::MemOrd mo) {
 612     return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, false, mo);
 613   }
 614 
 615   Node* store_oop_to_array(Node* ctl,
 616                            Node* obj,   // containing obj
 617                            Node* adr,   // actual adress to store val at
 618                            const TypePtr* adr_type,
 619                            Node* val,
 620                            const TypeOopPtr* val_type,
 621                            BasicType bt,
 622                            MemNode::MemOrd mo) {
 623     return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo);
 624   }
 625 
 626   // Could be an array or object we don't know at compile time (unsafe ref.)
 627   Node* store_oop_to_unknown(Node* ctl,
 628                              Node* obj,   // containing obj
 629                              Node* adr,   // actual adress to store val at
 630                              const TypePtr* adr_type,
 631                              Node* val,
 632                              BasicType bt,
 633                              MemNode::MemOrd mo,
 634                              bool mismatched = false);
 635 
 636   // For the few case where the barriers need special help
 637   void pre_barrier(bool do_load, Node* ctl,
 638                    Node* obj, Node* adr, uint adr_idx, Node* val, const TypeOopPtr* val_type,
 639                    Node* pre_val,
 640                    BasicType bt);
 641 
 642   void post_barrier(Node* ctl, Node* store, Node* obj, Node* adr, uint adr_idx,
 643                     Node* val, BasicType bt, bool use_precise);
 644 
 645   // Return addressing for an array element.
 646   Node* array_element_address(Node* ary, Node* idx, BasicType elembt,
 647                               // Optional constraint on the array size:
 648                               const TypeInt* sizetype = NULL,
 649                               // Optional control dependency (for example, on range check)
 650                               Node* ctrl = NULL);
 651 
 652   // Return a load of array element at idx.
 653   Node* load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype);
 654 
 655   //---------------- Dtrace support --------------------
 656   void make_dtrace_method_entry_exit(ciMethod* method, bool is_entry);
 657   void make_dtrace_method_entry(ciMethod* method) {
 658     make_dtrace_method_entry_exit(method, true);
 659   }
 660   void make_dtrace_method_exit(ciMethod* method) {
 661     make_dtrace_method_entry_exit(method, false);
 662   }
 663 
 664   //--------------- stub generation -------------------
 665  public:
 666   void gen_stub(address C_function,
 667                 const char *name,
 668                 int is_fancy_jump,
 669                 bool pass_tls,
 670                 bool return_pc);
 671 
 672   //---------- help for generating calls --------------
 673 
 674   // Do a null check on the receiver as it would happen before the call to
 675   // callee (with all arguments still on the stack).
 676   Node* null_check_receiver_before_call(ciMethod* callee) {
 677     assert(!callee->is_static(), "must be a virtual method");
 678     // Callsite signature can be different from actual method being called (i.e _linkTo* sites).
 679     // Use callsite signature always.
 680     ciMethod* declared_method = method()->get_method_at_bci(bci());
 681     const int nargs = declared_method->arg_size();
 682     inc_sp(nargs);
 683     Node* n = null_check_receiver();
 684     dec_sp(nargs);
 685     return n;
 686   }
 687 
 688   // Fill in argument edges for the call from argument(0), argument(1), ...
 689   // (The next step is to call set_edges_for_java_call.)
 690   void  set_arguments_for_java_call(CallJavaNode* call);
 691 
 692   // Fill in non-argument edges for the call.
 693   // Transform the call, and update the basics: control, i_o, memory.
 694   // (The next step is usually to call set_results_for_java_call.)
 695   void set_edges_for_java_call(CallJavaNode* call,
 696                                bool must_throw = false, bool separate_io_proj = false);
 697 
 698   // Finish up a java call that was started by set_edges_for_java_call.
 699   // Call add_exception on any throw arising from the call.
 700   // Return the call result (transformed).
 701   Node* set_results_for_java_call(CallJavaNode* call, bool separate_io_proj = false);
 702 
 703   // Similar to set_edges_for_java_call, but simplified for runtime calls.
 704   void  set_predefined_output_for_runtime_call(Node* call) {
 705     set_predefined_output_for_runtime_call(call, NULL, NULL);
 706   }
 707   void  set_predefined_output_for_runtime_call(Node* call,
 708                                                Node* keep_mem,
 709                                                const TypePtr* hook_mem);
 710   Node* set_predefined_input_for_runtime_call(SafePointNode* call);
 711 
 712   // Replace the call with the current state of the kit.  Requires
 713   // that the call was generated with separate io_projs so that
 714   // exceptional control flow can be handled properly.
 715   void replace_call(CallNode* call, Node* result, bool do_replaced_nodes = false);
 716 
 717   // helper functions for statistics
 718   void increment_counter(address counter_addr);   // increment a debug counter
 719   void increment_counter(Node*   counter_addr);   // increment a debug counter
 720 
 721   // Bail out to the interpreter right now
 722   // The optional klass is the one causing the trap.
 723   // The optional reason is debug information written to the compile log.
 724   // Optional must_throw is the same as with add_safepoint_edges.
 725   void uncommon_trap(int trap_request,
 726                      ciKlass* klass = NULL, const char* reason_string = NULL,
 727                      bool must_throw = false, bool keep_exact_action = false);
 728 
 729   // Shorthand, to avoid saying "Deoptimization::" so many times.
 730   void uncommon_trap(Deoptimization::DeoptReason reason,
 731                      Deoptimization::DeoptAction action,
 732                      ciKlass* klass = NULL, const char* reason_string = NULL,
 733                      bool must_throw = false, bool keep_exact_action = false) {
 734     uncommon_trap(Deoptimization::make_trap_request(reason, action),
 735                   klass, reason_string, must_throw, keep_exact_action);
 736   }
 737 
 738   // Bail out to the interpreter and keep exact action (avoid switching to Action_none).
 739   void uncommon_trap_exact(Deoptimization::DeoptReason reason,
 740                            Deoptimization::DeoptAction action,
 741                            ciKlass* klass = NULL, const char* reason_string = NULL,
 742                            bool must_throw = false) {
 743     uncommon_trap(Deoptimization::make_trap_request(reason, action),
 744                   klass, reason_string, must_throw, /*keep_exact_action=*/true);
 745   }
 746 
 747   // SP when bytecode needs to be reexecuted.
 748   virtual int reexecute_sp() { return sp(); }
 749 
 750   // Report if there were too many traps at the current method and bci.
 751   // Report if a trap was recorded, and/or PerMethodTrapLimit was exceeded.
 752   // If there is no MDO at all, report no trap unless told to assume it.
 753   bool too_many_traps(Deoptimization::DeoptReason reason) {
 754     return C->too_many_traps(method(), bci(), reason);
 755   }
 756 
 757   // Report if there were too many recompiles at the current method and bci.
 758   bool too_many_recompiles(Deoptimization::DeoptReason reason) {
 759     return C->too_many_recompiles(method(), bci(), reason);
 760   }
 761 
 762   // Returns the object (if any) which was created the moment before.
 763   Node* just_allocated_object(Node* current_control);
 764 
 765   static bool use_ReduceInitialCardMarks() {
 766     return (ReduceInitialCardMarks
 767             && Universe::heap()->can_elide_tlab_store_barriers());
 768   }
 769 
 770   // Sync Ideal and Graph kits.
 771   void sync_kit(IdealKit& ideal);
 772   void final_sync(IdealKit& ideal);
 773 
 774   // vanilla/CMS post barrier
 775   void write_barrier_post(Node *store, Node* obj,
 776                           Node* adr,  uint adr_idx, Node* val, bool use_precise);
 777 
 778   // Allow reordering of pre-barrier with oop store and/or post-barrier.
 779   // Used for load_store operations which loads old value.
 780   bool can_move_pre_barrier() const;
 781 
 782   // G1 pre/post barriers
 783   void g1_write_barrier_pre(bool do_load,
 784                             Node* obj,
 785                             Node* adr,
 786                             uint alias_idx,
 787                             Node* val,
 788                             const TypeOopPtr* val_type,
 789                             Node* pre_val,
 790                             BasicType bt);
 791 
 792   void g1_write_barrier_post(Node* store,
 793                              Node* obj,
 794                              Node* adr,
 795                              uint alias_idx,
 796                              Node* val,
 797                              BasicType bt,
 798                              bool use_precise);
 799   // Helper function for g1
 800   private:
 801   void g1_mark_card(IdealKit& ideal, Node* card_adr, Node* store, uint oop_alias_idx,
 802                     Node* index, Node* index_adr,
 803                     Node* buffer, const TypeFunc* tf);
 804 
 805   bool g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr, BasicType bt, uint adr_idx);
 806 
 807   bool g1_can_remove_post_barrier(PhaseTransform* phase, Node* store, Node* adr);
 808 
 809   public:
 810   // Helper function to round double arguments before a call
 811   void round_double_arguments(ciMethod* dest_method);
 812   void round_double_result(ciMethod* dest_method);
 813 
 814   // rounding for strict float precision conformance
 815   Node* precision_rounding(Node* n);
 816 
 817   // rounding for strict double precision conformance
 818   Node* dprecision_rounding(Node* n);
 819 
 820   // rounding for non-strict double stores
 821   Node* dstore_rounding(Node* n);
 822 
 823   // Helper functions for fast/slow path codes
 824   Node* opt_iff(Node* region, Node* iff);
 825   Node* make_runtime_call(int flags,
 826                           const TypeFunc* call_type, address call_addr,
 827                           const char* call_name,
 828                           const TypePtr* adr_type, // NULL if no memory effects
 829                           Node* parm0 = NULL, Node* parm1 = NULL,
 830                           Node* parm2 = NULL, Node* parm3 = NULL,
 831                           Node* parm4 = NULL, Node* parm5 = NULL,
 832                           Node* parm6 = NULL, Node* parm7 = NULL);
 833   enum {  // flag values for make_runtime_call
 834     RC_NO_FP = 1,               // CallLeafNoFPNode
 835     RC_NO_IO = 2,               // do not hook IO edges
 836     RC_NO_LEAF = 4,             // CallStaticJavaNode
 837     RC_MUST_THROW = 8,          // flag passed to add_safepoint_edges
 838     RC_NARROW_MEM = 16,         // input memory is same as output
 839     RC_UNCOMMON = 32,           // freq. expected to be like uncommon trap
 840     RC_LEAF = 0                 // null value:  no flags set
 841   };
 842 
 843   // merge in all memory slices from new_mem, along the given path
 844   void merge_memory(Node* new_mem, Node* region, int new_path);
 845   void make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize = false);
 846 
 847   // Helper functions to build synchronizations
 848   int next_monitor();
 849   Node* insert_mem_bar(int opcode, Node* precedent = NULL);
 850   Node* insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent = NULL);
 851   // Optional 'precedent' is appended as an extra edge, to force ordering.
 852   FastLockNode* shared_lock(Node* obj);
 853   void shared_unlock(Node* box, Node* obj);
 854 
 855   // helper functions for the fast path/slow path idioms
 856   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);
 857 
 858   // Generate an instance-of idiom.  Used by both the instance-of bytecode
 859   // and the reflective instance-of call.
 860   Node* gen_instanceof(Node *subobj, Node* superkls, bool safe_for_replace = false);
 861 
 862   // Generate a check-cast idiom.  Used by both the check-cast bytecode
 863   // and the array-store bytecode
 864   Node* gen_checkcast( Node *subobj, Node* superkls,
 865                        Node* *failure_control = NULL );
 866 
 867   Node* gen_subtype_check(Node* subklass, Node* superklass) {
 868     MergeMemNode* mem = merged_memory();
 869     Node* ctrl = control();
 870     Node* n = Phase::gen_subtype_check(subklass, superklass, &ctrl, mem, &_gvn);
 871     set_control(ctrl);
 872     return n;
 873   }
 874 
 875   // Exact type check used for predicted calls and casts.
 876   // Rewrites (*casted_receiver) to be casted to the stronger type.
 877   // (Caller is responsible for doing replace_in_map.)
 878   Node* type_check_receiver(Node* receiver, ciKlass* klass, float prob,
 879                             Node* *casted_receiver);
 880   Node* type_check(Node* recv_klass, const TypeKlassPtr* tklass, float prob);
 881 
 882   // implementation of object creation
 883   Node* set_output_for_allocation(AllocateNode* alloc,
 884                                   const TypeOopPtr* oop_type,
 885                                   bool deoptimize_on_exception=false);
 886   Node* get_layout_helper(Node* klass_node, jint& constant_value);
 887   Node* new_instance(Node* klass_node,
 888                      Node* slow_test = NULL,
 889                      Node* *return_size_val = NULL,
 890                      bool deoptimize_on_exception = false,
 891                      ValueTypeBaseNode* value_node = NULL);
 892   Node* new_array(Node* klass_node, Node* count_val, int nargs,
 893                   Node* *return_size_val = NULL,
 894                   bool deoptimize_on_exception = false);

 895   void initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs);
 896 
 897   // java.lang.String helpers
 898   Node* load_String_length(Node* ctrl, Node* str);
 899   Node* load_String_value(Node* ctrl, Node* str);
 900   Node* load_String_coder(Node* ctrl, Node* str);
 901   void store_String_value(Node* ctrl, Node* str, Node* value);
 902   void store_String_coder(Node* ctrl, Node* str, Node* value);
 903   Node* capture_memory(const TypePtr* src_type, const TypePtr* dst_type);
 904   Node* compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count);
 905   void inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count);
 906   void inflate_string_slow(Node* src, Node* dst, Node* start, Node* count);
 907 
 908   // Handy for making control flow
 909   IfNode* create_and_map_if(Node* ctrl, Node* tst, float prob, float cnt) {
 910     IfNode* iff = new IfNode(ctrl, tst, prob, cnt);// New IfNode's
 911     _gvn.set_type(iff, iff->Value(&_gvn)); // Value may be known at parse-time
 912     // Place 'if' on worklist if it will be in graph
 913     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later
 914     return iff;
 915   }
 916 
 917   IfNode* create_and_xform_if(Node* ctrl, Node* tst, float prob, float cnt) {
 918     IfNode* iff = new IfNode(ctrl, tst, prob, cnt);// New IfNode's
 919     _gvn.transform(iff);                           // Value may be known at parse-time
 920     // Place 'if' on worklist if it will be in graph
 921     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later
 922     return iff;
 923   }
 924 
 925   // Insert a loop predicate into the graph
 926   void add_predicate(int nargs = 0);
 927   void add_predicate_impl(Deoptimization::DeoptReason reason, int nargs);
 928 
 929   Node* make_constant_from_field(ciField* field, Node* obj);
 930 
 931   // Produce new array node of stable type
 932   Node* cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type);
 933 };
 934 
 935 // Helper class to support building of control flow branches. Upon
 936 // creation the map and sp at bci are cloned and restored upon de-
 937 // struction. Typical use:
 938 //
 939 // { PreserveJVMState pjvms(this);
 940 //   // code of new branch
 941 // }
 942 // // here the JVM state at bci is established
 943 
 944 class PreserveJVMState: public StackObj {
 945  protected:
 946   GraphKit*      _kit;
 947 #ifdef ASSERT
 948   int            _block;  // PO of current block, if a Parse
 949   int            _bci;
 950 #endif
 951   SafePointNode* _map;
 952   uint           _sp;
 953 
 954  public:
 955   PreserveJVMState(GraphKit* kit, bool clone_map = true);
 956   ~PreserveJVMState();
 957 };
 958 
 959 // Helper class to build cutouts of the form if (p) ; else {x...}.
 960 // The code {x...} must not fall through.
 961 // The kit's main flow of control is set to the "then" continuation of if(p).
 962 class BuildCutout: public PreserveJVMState {
 963  public:
 964   BuildCutout(GraphKit* kit, Node* p, float prob, float cnt = COUNT_UNKNOWN);
 965   ~BuildCutout();
 966 };
 967 
 968 // Helper class to preserve the original _reexecute bit and _sp and restore
 969 // them back
 970 class PreserveReexecuteState: public StackObj {
 971  protected:
 972   GraphKit*                 _kit;
 973   uint                      _sp;
 974   JVMState::ReexecuteState  _reexecute;
 975 
 976  public:
 977   PreserveReexecuteState(GraphKit* kit);
 978   ~PreserveReexecuteState();
 979 };
 980 
 981 #endif // SHARE_VM_OPTO_GRAPHKIT_HPP
--- EOF ---