1 /*
  2  * Copyright (c) 2001, 2026, 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.
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 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/inlinetypenode.hpp"
 37 #include "opto/mulnode.hpp"
 38 #include "opto/phaseX.hpp"
 39 #include "opto/subnode.hpp"
 40 #include "opto/type.hpp"
 41 #include "runtime/deoptimization.hpp"
 42 
 43 class BarrierSetC2;
 44 class FastLockNode;
 45 class FastUnlockNode;
 46 class IdealKit;
 47 class LibraryCallKit;
 48 class Parse;
 49 class RootNode;
 50 
 51 //-----------------------------------------------------------------------------
 52 //----------------------------GraphKit-----------------------------------------
 53 // Toolkit for building the common sorts of subgraphs.
 54 // Does not know about bytecode parsing or type-flow results.
 55 // It is able to create graphs implementing the semantics of most
 56 // or all bytecodes, so that it can expand intrinsics and calls.
 57 // It may depend on JVMState structure, but it must not depend
 58 // on specific bytecode streams.
 59 class GraphKit : public Phase {
 60   friend class PreserveJVMState;
 61 
 62  protected:
 63   ciEnv*            _env;       // Compilation environment
 64   PhaseGVN         &_gvn;       // Some optimizations while parsing
 65   SafePointNode*    _map;       // Parser map from JVM to Nodes
 66   SafePointNode*    _exceptions;// Parser map(s) for exception state(s)
 67   int               _bci;       // JVM Bytecode Pointer
 68   ciMethod*         _method;    // JVM Current Method
 69   BarrierSetC2*     _barrier_set;
 70 #ifdef ASSERT
 71   uint              _worklist_size;
 72 #endif
 73 
 74  private:
 75   int               _sp;        // JVM Expression Stack Pointer; don't modify directly!
 76 
 77  private:
 78   SafePointNode*     map_not_null() const {
 79     assert(_map != nullptr, "must call stopped() to test for reset compiler map");
 80     return _map;
 81   }
 82 
 83  public:
 84   GraphKit();                   // empty constructor
 85   GraphKit(JVMState* jvms, PhaseGVN* gvn = nullptr);     // the JVM state on which to operate
 86 
 87   // Create a GraphKit from a debug state, useful for various kinds of macro expansion
 88   GraphKit(const SafePointNode* sft, PhaseIterGVN& igvn);
 89 
 90 #ifdef ASSERT
 91   ~GraphKit() {
 92     assert(failing_internal() || !has_exceptions(),
 93            "unless compilation failed, user must call transfer_exceptions_into_jvms");
 94   }
 95 #endif
 96 
 97   virtual Parse*          is_Parse()          const { return nullptr; }
 98   virtual LibraryCallKit* is_LibraryCallKit() const { return nullptr; }
 99 
100   ciEnv*        env()               const { return _env; }
101   PhaseGVN&     gvn()               const { return _gvn; }
102   void*         barrier_set_state() const { return C->barrier_set_state(); }
103 
104   void record_for_igvn(Node* n) const { _gvn.record_for_igvn(n); }
105   void remove_for_igvn(Node* n) const { C->remove_for_igvn(n); }
106 
107   // Handy well-known nodes:
108   Node*         null()          const { return zerocon(T_OBJECT); }
109   Node*         top()           const { return C->top(); }
110   RootNode*     root()          const { return C->root(); }
111 
112   // Create or find a constant node
113   Node* intcon(jint con)        const { return _gvn.intcon(con); }
114   Node* longcon(jlong con)      const { return _gvn.longcon(con); }
115   Node* integercon(jlong con, BasicType bt)   const {
116     if (bt == T_INT) {
117       return intcon(checked_cast<jint>(con));
118     }
119     assert(bt == T_LONG, "basic type not an int or long");
120     return longcon(con);
121   }
122   Node* makecon(const Type *t)  const { return _gvn.makecon(t); }
123   Node* zerocon(BasicType bt)   const { return _gvn.zerocon(bt); }
124   // (See also macro MakeConX in type.hpp, which uses intcon or longcon.)
125 
126   jint  find_int_con(Node* n, jint value_if_unknown) {
127     return _gvn.find_int_con(n, value_if_unknown);
128   }
129   jlong find_long_con(Node* n, jlong value_if_unknown) {
130     return _gvn.find_long_con(n, value_if_unknown);
131   }
132   // (See also macro find_intptr_t_con in type.hpp, which uses one of these.)
133 
134   // JVM State accessors:
135   // Parser mapping from JVM indices into Nodes.
136   // Low slots are accessed by the StartNode::enum.
137   // Then come the locals at StartNode::Parms to StartNode::Parms+max_locals();
138   // Then come JVM stack slots.
139   // Finally come the monitors, if any.
140   // See layout accessors in class JVMState.
141 
142   SafePointNode*     map()      const { return _map; }
143   bool               has_exceptions() const { return _exceptions != nullptr; }
144   JVMState*          jvms()     const { return map_not_null()->_jvms; }
145   int                sp()       const { return _sp; }
146   int                bci()      const { return _bci; }
147   Bytecodes::Code    java_bc()  const;
148   ciMethod*          method()   const { return _method; }
149 
150   void set_jvms(JVMState* jvms)       { set_map(jvms->map());
151                                         assert(jvms == this->jvms(), "sanity");
152                                         _sp = jvms->sp();
153                                         _bci = jvms->bci();
154                                         _method = jvms->has_method() ? jvms->method() : nullptr; }
155   void set_map(SafePointNode* m)      { _map = m; DEBUG_ONLY(verify_map()); }
156   void set_sp(int sp)                 { assert(sp >= 0, "sp must be non-negative: %d", sp); _sp = sp; }
157   void clean_stack(int from_sp); // clear garbage beyond from_sp to top
158 
159   void inc_sp(int i)                  { set_sp(sp() + i); }
160   void dec_sp(int i)                  { set_sp(sp() - i); }
161   void set_bci(int bci)               { _bci = bci; }
162 
163   // Make sure jvms has current bci & sp.
164   JVMState* sync_jvms() const;
165   JVMState* sync_jvms_for_reexecute();
166 
167 #ifdef ASSERT
168   // Make sure JVMS has an updated copy of bci and sp.
169   // Also sanity-check method, depth, and monitor depth.
170   bool jvms_in_sync() const;
171 
172   // Make sure the map looks OK.
173   void verify_map() const;
174 
175   // Make sure a proposed exception state looks OK.
176   static void verify_exception_state(SafePointNode* ex_map);
177 #endif
178 
179   // Clone the existing map state.  (Implements PreserveJVMState.)
180   SafePointNode* clone_map();
181 
182   // Reverses the work done by clone_map(). Should only be used when the node returned by
183   // clone_map() is ultimately not used. Calling Node::destruct directly in the previously
184   // mentioned circumstance instead of this method may result in use-after-free.
185   void destruct_map_clone(SafePointNode* sfp);
186 
187   // Set the map to a clone of the given one.
188   void set_map_clone(SafePointNode* m);
189 
190   // Tell if the compilation is failing.
191   bool failing() const { return C->failing(); }
192   bool failing_internal() const { return C->failing_internal(); }
193 
194   // Set _map to null, signalling a stop to further bytecode execution.
195   // Preserve the map intact for future use, and return it back to the caller.
196   SafePointNode* stop() { SafePointNode* m = map(); set_map(nullptr); return m; }
197 
198   // Stop, but first smash the map's inputs to null, to mark it dead.
199   void stop_and_kill_map();
200 
201   // Tell if _map is null, or control is top.
202   bool stopped();
203 
204   // Tell if this method or any caller method has exception handlers.
205   bool has_exception_handler();
206 
207   // Save an exception without blowing stack contents or other JVM state.
208   // (The extra pointer is stuck with add_req on the map, beyond the JVMS.)
209   static void set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop);
210 
211   // Recover a saved exception from its map.
212   static Node* saved_ex_oop(SafePointNode* ex_map);
213 
214   // Recover a saved exception from its map, and remove it from the map.
215   static Node* clear_saved_ex_oop(SafePointNode* ex_map);
216 
217 #ifdef ASSERT
218   // Recover a saved exception from its map, and remove it from the map.
219   static bool has_saved_ex_oop(SafePointNode* ex_map);
220 #endif
221 
222   // Push an exception in the canonical position for handlers (stack(0)).
223   void push_ex_oop(Node* ex_oop) {
224     ensure_stack(1);  // ensure room to push the exception
225     set_stack(0, ex_oop);
226     set_sp(1);
227     clean_stack(1);
228   }
229 
230   // Detach and return an exception state.
231   SafePointNode* pop_exception_state() {
232     SafePointNode* ex_map = _exceptions;
233     if (ex_map != nullptr) {
234       _exceptions = ex_map->next_exception();
235       ex_map->set_next_exception(nullptr);
236       DEBUG_ONLY(verify_exception_state(ex_map));
237     }
238     return ex_map;
239   }
240 
241   // Add an exception, using the given JVM state, without commoning.
242   void push_exception_state(SafePointNode* ex_map) {
243     DEBUG_ONLY(verify_exception_state(ex_map));
244     ex_map->set_next_exception(_exceptions);
245     _exceptions = ex_map;
246   }
247 
248   // Turn the current JVM state into an exception state, appending the ex_oop.
249   SafePointNode* make_exception_state(Node* ex_oop);
250 
251   // Add an exception, using the given JVM state.
252   // Combine all exceptions with a common exception type into a single state.
253   // (This is done via combine_exception_states.)
254   void add_exception_state(SafePointNode* ex_map);
255 
256   // Combine all exceptions of any sort whatever into a single master state.
257   SafePointNode* combine_and_pop_all_exception_states() {
258     if (_exceptions == nullptr)  return nullptr;
259     SafePointNode* phi_map = pop_exception_state();
260     SafePointNode* ex_map;
261     while ((ex_map = pop_exception_state()) != nullptr) {
262       combine_exception_states(ex_map, phi_map);
263     }
264     return phi_map;
265   }
266 
267   // Combine the two exception states, building phis as necessary.
268   // The second argument is updated to include contributions from the first.
269   void combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map);
270 
271   // Reset the map to the given state.  If there are any half-finished phis
272   // in it (created by combine_exception_states), transform them now.
273   // Returns the exception oop.  (Caller must call push_ex_oop if required.)
274   Node* use_exception_state(SafePointNode* ex_map);
275 
276   // Collect exceptions from a given JVM state into my exception list.
277   void add_exception_states_from(JVMState* jvms);
278 
279   // Collect all raised exceptions into the current JVM state.
280   // Clear the current exception list and map, returns the combined states.
281   JVMState* transfer_exceptions_into_jvms();
282 
283   // Helper to throw a built-in exception.
284   // The JVMS must allow the bytecode to be re-executed via an uncommon trap.
285   void builtin_throw(Deoptimization::DeoptReason reason);
286   void builtin_throw(Deoptimization::DeoptReason reason,
287                      ciInstance* exception_object,
288                      bool allow_too_many_traps);
289   bool builtin_throw_too_many_traps(Deoptimization::DeoptReason reason,
290                                     ciInstance* exception_object);
291  private:
292   bool is_builtin_throw_hot(Deoptimization::DeoptReason reason);
293   ciInstance* builtin_throw_exception(Deoptimization::DeoptReason reason) const;
294 
295  public:
296 
297   // Helper to check the JavaThread::_should_post_on_exceptions flag
298   // and branch to an uncommon_trap if it is true (with the specified reason and must_throw)
299   void uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
300                                                   bool must_throw) ;
301 
302   // Helper Functions for adding debug information
303   void kill_dead_locals();
304 #ifdef ASSERT
305   bool dead_locals_are_killed();
306 #endif
307   // The call may deoptimize.  Supply required JVM state as debug info.
308   // If must_throw is true, the call is guaranteed not to return normally.
309   void add_safepoint_edges(SafePointNode* call,
310                            bool must_throw = false);
311 
312   // How many stack inputs does the current BC consume?
313   // And, how does the stack change after the bytecode?
314   // Returns false if unknown.
315   bool compute_stack_effects(int& inputs, int& depth);
316 
317   // Add a fixed offset to a pointer
318   Node* basic_plus_adr(Node* base, Node* ptr, intptr_t offset) {
319     return basic_plus_adr(base, ptr, MakeConX(offset));
320   }
321   Node* basic_plus_adr(Node* base, intptr_t offset) {
322     return basic_plus_adr(base, base, MakeConX(offset));
323   }
324   // Add a variable offset to a pointer
325   Node* basic_plus_adr(Node* base, Node* offset) {
326     return basic_plus_adr(base, base, offset);
327   }
328   Node* basic_plus_adr(Node* base, Node* ptr, Node* offset);
329 
330   Node* off_heap_plus_addr(Node* ptr, intptr_t offset) {
331     return basic_plus_adr(top(), ptr, MakeConX(offset));
332   }
333 
334   Node* off_heap_plus_addr(Node* ptr, Node* offset) {
335     return basic_plus_adr(top(), ptr, offset);
336   }
337 
338   // Some convenient shortcuts for common nodes
339   Node* IfTrue(IfNode* iff)                   { return _gvn.transform(new IfTrueNode(iff));      }
340   Node* IfFalse(IfNode* iff)                  { return _gvn.transform(new IfFalseNode(iff));     }
341 
342   Node* AddI(Node* l, Node* r)                { return _gvn.transform(new AddINode(l, r));       }
343   Node* SubI(Node* l, Node* r)                { return _gvn.transform(new SubINode(l, r));       }
344   Node* MulI(Node* l, Node* r)                { return _gvn.transform(new MulINode(l, r));       }
345   Node* DivI(Node* ctl, Node* l, Node* r)     { return _gvn.transform(new DivINode(ctl, l, r));  }
346 
347   Node* AndI(Node* l, Node* r)                { return _gvn.transform(new AndINode(l, r));       }
348   Node* OrI(Node* l, Node* r)                 { return _gvn.transform(new OrINode(l, r));        }
349   Node* XorI(Node* l, Node* r)                { return _gvn.transform(new XorINode(l, r));       }
350 
351   Node* MaxI(Node* l, Node* r)                { return _gvn.transform(new MaxINode(l, r));       }
352   Node* MinI(Node* l, Node* r)                { return _gvn.transform(new MinINode(l, r));       }
353 
354   Node* LShiftI(Node* l, Node* r)             { return _gvn.transform(new LShiftINode(l, r));    }
355   Node* RShiftI(Node* l, Node* r)             { return _gvn.transform(new RShiftINode(l, r));    }
356   Node* URShiftI(Node* l, Node* r)            { return _gvn.transform(new URShiftINode(l, r));   }
357 
358   Node* CmpI(Node* l, Node* r)                { return _gvn.transform(new CmpINode(l, r));       }
359   Node* CmpL(Node* l, Node* r)                { return _gvn.transform(new CmpLNode(l, r));       }
360   Node* CmpP(Node* l, Node* r)                { return _gvn.transform(new CmpPNode(l, r));       }
361   Node* Bool(Node* cmp, BoolTest::mask relop) { return _gvn.transform(new BoolNode(cmp, relop)); }
362 
363   Node* AddP(Node* b, Node* a, Node* o)       { return _gvn.transform(AddPNode::make_with_base(b, a, o)); }
364 
365   // Convert between int and long, and size_t.
366   // (See macros ConvI2X, etc., in type.hpp for ConvI2X, etc.)
367   Node* ConvI2L(Node* offset);
368   Node* ConvI2UL(Node* offset);
369   Node* ConvL2I(Node* offset);
370   // Find out the klass of an object.
371   Node* load_object_klass(Node* object);
372   // Find out the length of an array.
373   Node* load_array_length(Node* array);
374   // Cast array allocation's length as narrow as possible.
375   // If replace_length_in_map is true, replace length with CastIINode in map.
376   // This method is invoked after creating/moving ArrayAllocationNode or in load_array_length
377   Node* array_ideal_length(AllocateArrayNode* alloc,
378                            const TypeOopPtr* oop_type,
379                            bool replace_length_in_map);
380 
381 
382   // Helper function to do a null pointer check or ZERO check based on type.
383   // Throw an exception if a given value is null.
384   // Return the value cast to not-null.
385   // Be clever about equivalent dominating null checks.
386   Node* null_check_common(Node* value, BasicType type,
387                           bool assert_null = false,
388                           Node* *null_control = nullptr,
389                           bool speculative = false,
390                           bool null_marker_check = false);
391   Node* null_check(Node* value, BasicType type = T_OBJECT) {
392     return null_check_common(value, type, false, nullptr, !_gvn.type(value)->speculative_maybe_null());
393   }
394   Node* null_check_receiver() {
395     return null_check(argument(0));
396   }
397   Node* zero_check_int(Node* value) {
398     assert(value->bottom_type()->basic_type() == T_INT,
399            "wrong type: %s", type2name(value->bottom_type()->basic_type()));
400     return null_check_common(value, T_INT);
401   }
402   Node* zero_check_long(Node* value) {
403     assert(value->bottom_type()->basic_type() == T_LONG,
404            "wrong type: %s", type2name(value->bottom_type()->basic_type()));
405     return null_check_common(value, T_LONG);
406   }
407   // Throw an uncommon trap if a given value is __not__ null.
408   // Return the value cast to null, and be clever about dominating checks.
409   Node* null_assert(Node* value, BasicType type = T_OBJECT) {
410     return null_check_common(value, type, true, nullptr, _gvn.type(value)->speculative_always_null());
411   }
412 
413   // Check if value is null and abort if it is
414   Node* must_be_not_null(Node* value, bool do_replace_in_map);
415 
416   // Null check oop.  Return null-path control into (*null_control).
417   // Return a cast-not-null node which depends on the not-null control.
418   // If never_see_null, use an uncommon trap (*null_control sees a top).
419   // The cast is not valid along the null path; keep a copy of the original.
420   // If safe_for_replace, then we can replace the value with the cast
421   // in the parsing map (the cast is guaranteed to dominate the map)
422   Node* null_check_oop(Node* value, Node* *null_control,
423                        bool never_see_null = false,
424                        bool safe_for_replace = false,
425                        bool speculative = false);
426 
427   // Check the null_seen bit.
428   bool seems_never_null(Node* obj, ciProfileData* data, bool& speculating);
429 
430   void guard_klass_being_initialized(Node* klass);
431   void guard_init_thread(Node* klass);
432 
433   void clinit_barrier(ciInstanceKlass* ik, ciMethod* context);
434 
435   // Check for unique class for receiver at call
436   ciKlass* profile_has_unique_klass() {
437     ciCallProfile profile = method()->call_profile_at_bci(bci());
438     if (profile.count() >= 0 &&         // no cast failures here
439         profile.has_receiver(0) &&
440         profile.morphism() == 1) {
441       return profile.receiver(0);
442     }
443     return nullptr;
444   }
445 
446   // record type from profiling with the type system
447   Node* record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind);
448   void record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc);
449   void record_profiled_parameters_for_speculation();
450   void record_profiled_return_for_speculation();
451   Node* record_profiled_receiver_for_speculation(Node* n);
452 
453   // Use the type profile to narrow an object type.
454   Node* maybe_cast_profiled_receiver(Node* not_null_obj,
455                                      const TypeKlassPtr* require_klass,
456                                      ciKlass* spec,
457                                      bool safe_for_replace);
458 
459   // Cast obj to type and emit guard unless we had too many traps here already
460   Node* maybe_cast_profiled_obj(Node* obj,
461                                 ciKlass* type,
462                                 bool not_null = false);
463 
464   // Cast obj to not-null on this path
465   Node* cast_not_null(Node* obj, bool do_replace_in_map = true);
466   // Replace all occurrences of one node by another.
467   void replace_in_map(Node* old, Node* neww);
468 
469   Node* maybe_narrow_object_type(Node* obj, ciKlass* type, bool maybe_larval);
470 
471   void  push(Node* n)     { map_not_null();        _map->set_stack(_map->_jvms,   _sp++        , n); }
472   Node* pop()             { map_not_null(); return _map->stack(    _map->_jvms, --_sp             ); }
473   Node* peek(int off = 0) { map_not_null(); return _map->stack(    _map->_jvms,   _sp - off - 1   ); }
474 
475   void push_pair(Node* ldval) {
476     push(ldval);
477     push(top());  // the halfword is merely a placeholder
478   }
479   void push_pair_local(int i) {
480     // longs are stored in locals in "push" order
481     push(  local(i+0) );  // the real value
482     assert(local(i+1) == top(), "");
483     push(top());  // halfword placeholder
484   }
485   Node* pop_pair() {
486     // the second half is pushed last & popped first; it contains exactly nothing
487     Node* halfword = pop();
488     assert(halfword == top(), "");
489     // the long bits are pushed first & popped last:
490     return pop();
491   }
492   void set_pair_local(int i, Node* lval) {
493     // longs are stored in locals as a value/half pair (like doubles)
494     set_local(i+0, lval);
495     set_local(i+1, top());
496   }
497 
498   // Push the node, which may be zero, one, or two words.
499   void push_node(BasicType n_type, Node* n) {
500     int n_size = type2size[n_type];
501     if      (n_size == 1)  push(      n );  // T_INT, ...
502     else if (n_size == 2)  push_pair( n );  // T_DOUBLE, T_LONG
503     else                   { assert(n_size == 0, "must be T_VOID"); }
504   }
505 
506   Node* pop_node(BasicType n_type) {
507     int n_size = type2size[n_type];
508     if      (n_size == 1)  return pop();
509     else if (n_size == 2)  return pop_pair();
510     else                   return nullptr;
511   }
512 
513   Node* control()               const { return map_not_null()->control(); }
514   Node* i_o()                   const { return map_not_null()->i_o(); }
515   Node* returnadr()             const { return map_not_null()->returnadr(); }
516   Node* frameptr()              const { return map_not_null()->frameptr(); }
517   Node* local(uint idx)         const { map_not_null(); return _map->local(      _map->_jvms, idx); }
518   Node* stack(uint idx)         const { map_not_null(); return _map->stack(      _map->_jvms, idx); }
519   Node* argument(uint idx)      const { map_not_null(); return _map->argument(   _map->_jvms, idx); }
520   Node* monitor_box(uint idx)   const { map_not_null(); return _map->monitor_box(_map->_jvms, idx); }
521   Node* monitor_obj(uint idx)   const { map_not_null(); return _map->monitor_obj(_map->_jvms, idx); }
522 
523   void set_control  (Node* c)         { map_not_null()->set_control(c); }
524   void set_i_o      (Node* c)         { map_not_null()->set_i_o(c); }
525   void set_local(uint idx, Node* c)   { map_not_null(); _map->set_local(   _map->_jvms, idx, c); }
526   void set_stack(uint idx, Node* c)   { map_not_null(); _map->set_stack(   _map->_jvms, idx, c); }
527   void set_argument(uint idx, Node* c){ map_not_null(); _map->set_argument(_map->_jvms, idx, c); }
528   void ensure_stack(uint stk_size)    { map_not_null(); _map->ensure_stack(_map->_jvms, stk_size); }
529 
530   // Access unaliased memory
531   Node* memory(uint alias_idx);
532   Node* memory(const TypePtr *tp) { return memory(C->get_alias_index(tp)); }
533   Node* memory(Node* adr) { return memory(_gvn.type(adr)->is_ptr()); }
534 
535   // Access immutable memory
536   Node* immutable_memory() { return C->immutable_memory(); }
537 
538   // Set unaliased memory
539   void set_memory(Node* c, uint alias_idx) { merged_memory()->set_memory_at(alias_idx, c); }
540   void set_memory(Node* c, const TypePtr *tp) { set_memory(c,C->get_alias_index(tp)); }
541   void set_memory(Node* c, Node* adr) { set_memory(c,_gvn.type(adr)->is_ptr()); }
542 
543   // Get the entire memory state (probably a MergeMemNode), and reset it
544   // (The resetting prevents somebody from using the dangling Node pointer.)
545   Node* reset_memory();
546 
547   // Get the entire memory state, asserted to be a MergeMemNode.
548   MergeMemNode* merged_memory() {
549     Node* mem = map_not_null()->memory();
550     assert(mem->is_MergeMem(), "parse memory is always pre-split");
551     return mem->as_MergeMem();
552   }
553 
554   // Set the entire memory state; produce a new MergeMemNode.
555   void set_all_memory(Node* newmem);
556 
557   // Create a memory projection from the call, then set_all_memory.
558   void set_all_memory_call(Node* call, bool separate_io_proj = false);
559 
560   // Create a LoadNode, reading from the parser's memory state.
561   // (Note:  require_atomic_access is useful only with T_LONG.)
562   //
563   // We choose the unordered semantics by default because we have
564   // adapted the `do_put_xxx' and `do_get_xxx' procedures for the case
565   // of volatile fields.
566   Node* make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
567                   MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency = LoadNode::DependsOnlyOnTest,
568                   bool require_atomic_access = false, bool unaligned = false,
569                   bool mismatched = false, bool unsafe = false, uint8_t barrier_data = 0);
570 
571   // Create & transform a StoreNode and store the effect into the
572   // parser's memory state.
573   //
574   // We must ensure that stores of object references will be visible
575   // only after the object's initialization. So the clients of this
576   // procedure must indicate that the store requires `release'
577   // semantics, if the stored value is an object reference that might
578   // point to a new object and may become externally visible.
579   // Return the new StoreXNode
580   Node* store_to_memory(Node* ctl, Node* adr, Node* val, BasicType bt,
581                         MemNode::MemOrd,
582                         bool require_atomic_access = false,
583                         bool unaligned = false,
584                         bool mismatched = false,
585                         bool unsafe = false,
586                         int barrier_data = 0);
587 
588   // Perform decorated accesses
589 
590   Node* access_store_at(Node* obj,   // containing obj
591                         Node* adr,   // actual address to store val at
592                         const TypePtr* adr_type,
593                         Node* val,
594                         const Type* val_type,
595                         BasicType bt,
596                         DecoratorSet decorators,
597                         bool safe_for_replace = true,
598                         const InlineTypeNode* vt = nullptr);
599 
600   Node* access_load_at(Node* obj,   // containing obj
601                        Node* adr,   // actual address to load val at
602                        const TypePtr* adr_type,
603                        const Type* val_type,
604                        BasicType bt,
605                        DecoratorSet decorators,
606                        Node* ctl = nullptr);
607 
608   Node* access_load(Node* adr,   // actual address to load val at
609                     const Type* val_type,
610                     BasicType bt,
611                     DecoratorSet decorators);
612 
613   Node* access_atomic_cmpxchg_val_at(Node* obj,
614                                      Node* adr,
615                                      const TypePtr* adr_type,
616                                      int alias_idx,
617                                      Node* expected_val,
618                                      Node* new_val,
619                                      const Type* value_type,
620                                      BasicType bt,
621                                      DecoratorSet decorators);
622 
623   Node* access_atomic_cmpxchg_bool_at(Node* obj,
624                                       Node* adr,
625                                       const TypePtr* adr_type,
626                                       int alias_idx,
627                                       Node* expected_val,
628                                       Node* new_val,
629                                       const Type* value_type,
630                                       BasicType bt,
631                                       DecoratorSet decorators);
632 
633   Node* access_atomic_xchg_at(Node* obj,
634                               Node* adr,
635                               const TypePtr* adr_type,
636                               int alias_idx,
637                               Node* new_val,
638                               const Type* value_type,
639                               BasicType bt,
640                               DecoratorSet decorators);
641 
642   Node* access_atomic_add_at(Node* obj,
643                              Node* adr,
644                              const TypePtr* adr_type,
645                              int alias_idx,
646                              Node* new_val,
647                              const Type* value_type,
648                              BasicType bt,
649                              DecoratorSet decorators);
650 
651   void access_clone(Node* src, Node* dst, Node* size, bool is_array);
652 
653   // Return addressing for an array element.
654   Node* array_element_address(Node* ary, Node* idx, BasicType elembt,
655                               // Optional constraint on the array size:
656                               const TypeInt* sizetype = nullptr,
657                               // Optional control dependency (for example, on range check)
658                               Node* ctrl = nullptr);
659   Node* cast_to_flat_array(Node* array, ciInlineKlass* elem_vk);
660   Node* cast_to_flat_array_exact(Node* array, ciInlineKlass* elem_vk, bool is_null_free, bool is_atomic);
661 
662   // Return a load of array element at idx.
663   Node* load_array_element(Node* ary, Node* idx, const TypeAryPtr* arytype, bool set_ctrl);
664 
665   //---------------- Dtrace support --------------------
666   void make_dtrace_method_entry_exit(ciMethod* method, bool is_entry);
667   void make_dtrace_method_entry(ciMethod* method) {
668     make_dtrace_method_entry_exit(method, true);
669   }
670   void make_dtrace_method_exit(ciMethod* method) {
671     make_dtrace_method_entry_exit(method, false);
672   }
673 
674   //--------------- stub generation -------------------
675  public:
676   void gen_stub(address C_function,
677                 const char *name,
678                 int is_fancy_jump,
679                 bool pass_tls,
680                 bool return_pc);
681 
682   //---------- help for generating calls --------------
683 
684   // Do a null check on the receiver as it would happen before the call to
685   // callee (with all arguments still on the stack).
686   Node* null_check_receiver_before_call(ciMethod* callee) {
687     assert(!callee->is_static(), "must be a virtual method");
688     // Callsite signature can be different from actual method being called (i.e _linkTo* sites).
689     // Use callsite signature always.
690     ciMethod* declared_method = method()->get_method_at_bci(bci());
691     const int nargs = declared_method->arg_size();
692     inc_sp(nargs);
693     Node* n = null_check_receiver();
694     dec_sp(nargs);
695     return n;
696   }
697 
698   // Fill in argument edges for the call from argument(0), argument(1), ...
699   // (The next step is to call set_edges_for_java_call.)
700   void  set_arguments_for_java_call(CallJavaNode* call, bool is_late_inline = false);
701 
702   // Fill in non-argument edges for the call.
703   // Transform the call, and update the basics: control, i_o, memory.
704   // (The next step is usually to call set_results_for_java_call.)
705   void set_edges_for_java_call(CallJavaNode* call,
706                                bool must_throw = false, bool separate_io_proj = false);
707 
708   // Finish up a java call that was started by set_edges_for_java_call.
709   // Call add_exception on any throw arising from the call.
710   // Return the call result (transformed).
711   Node* set_results_for_java_call(CallJavaNode* call, bool separate_io_proj = false, bool deoptimize = false);
712 
713   // Similar to set_edges_for_java_call, but simplified for runtime calls.
714   void  set_predefined_output_for_runtime_call(Node* call) {
715     set_predefined_output_for_runtime_call(call, nullptr, nullptr);
716   }
717   void  set_predefined_output_for_runtime_call(Node* call,
718                                                Node* keep_mem,
719                                                const TypePtr* hook_mem);
720   Node* set_predefined_input_for_runtime_call(SafePointNode* call, Node* narrow_mem = nullptr);
721 
722   // Replace the call with the current state of the kit.  Requires
723   // that the call was generated with separate io_projs so that
724   // exceptional control flow can be handled properly.
725   void replace_call(CallNode* call, Node* result, bool do_replaced_nodes = false, bool do_asserts = true);
726 
727   // helper functions for statistics
728   void increment_counter(address counter_addr);   // increment a debug counter
729   void increment_counter(Node*   counter_addr);   // increment a debug counter
730 
731   void halt(Node* ctrl, Node* frameptr, const char* reason, bool generate_code_in_product = true);
732 
733   // Bail out to the interpreter right now
734   // The optional klass is the one causing the trap.
735   // The optional reason is debug information written to the compile log.
736   // Optional must_throw is the same as with add_safepoint_edges.
737   Node* uncommon_trap(int trap_request,
738                      ciKlass* klass = nullptr, const char* reason_string = nullptr,
739                      bool must_throw = false, bool keep_exact_action = false);
740 
741   // Shorthand, to avoid saying "Deoptimization::" so many times.
742   Node* uncommon_trap(Deoptimization::DeoptReason reason,
743                      Deoptimization::DeoptAction action,
744                      ciKlass* klass = nullptr, const char* reason_string = nullptr,
745                      bool must_throw = false, bool keep_exact_action = false) {
746     return uncommon_trap(Deoptimization::make_trap_request(reason, action),
747                   klass, reason_string, must_throw, keep_exact_action);
748   }
749 
750   // Bail out to the interpreter and keep exact action (avoid switching to Action_none).
751   Node* uncommon_trap_exact(Deoptimization::DeoptReason reason,
752                            Deoptimization::DeoptAction action,
753                            ciKlass* klass = nullptr, const char* reason_string = nullptr,
754                            bool must_throw = false) {
755     return uncommon_trap(Deoptimization::make_trap_request(reason, action),
756                   klass, reason_string, must_throw, /*keep_exact_action=*/true);
757   }
758 
759   // SP when bytecode needs to be reexecuted.
760   virtual int reexecute_sp() { return sp(); }
761 
762   // Report if there were too many traps at the current method and bci.
763   // Report if a trap was recorded, and/or PerMethodTrapLimit was exceeded.
764   // If there is no MDO at all, report no trap unless told to assume it.
765   bool too_many_traps(Deoptimization::DeoptReason reason) {
766     return C->too_many_traps(method(), bci(), reason);
767   }
768 
769   // Report if there were too many recompiles at the current method and bci.
770   bool too_many_recompiles(Deoptimization::DeoptReason reason) {
771     return C->too_many_recompiles(method(), bci(), reason);
772   }
773 
774   bool too_many_traps_or_recompiles(Deoptimization::DeoptReason reason) {
775       return C->too_many_traps_or_recompiles(method(), bci(), reason);
776   }
777 
778   // Returns the object (if any) which was created the moment before.
779   Node* just_allocated_object(Node* current_control);
780 
781   // Sync Ideal and Graph kits.
782   void sync_kit(IdealKit& ideal);
783   void final_sync(IdealKit& ideal);
784 
785   public:
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 = nullptr, Node* parm1 = nullptr,
793                           Node* parm2 = nullptr, Node* parm3 = nullptr,
794                           Node* parm4 = nullptr, Node* parm5 = nullptr,
795                           Node* parm6 = nullptr, Node* parm7 = nullptr);
796 
797   Node* sign_extend_byte(Node* in);
798   Node* sign_extend_short(Node* in);
799 
800   enum {  // flag values for make_runtime_call
801     RC_NO_FP = 1,               // CallLeafNoFPNode
802     RC_NO_IO = 2,               // do not hook IO edges
803     RC_NO_LEAF = 4,             // CallStaticJavaNode
804     RC_MUST_THROW = 8,          // flag passed to add_safepoint_edges
805     RC_NARROW_MEM = 16,         // input memory is same as output
806     RC_UNCOMMON = 32,           // freq. expected to be like uncommon trap
807     RC_VECTOR = 64,             // CallLeafVectorNode
808     RC_PURE = 128,              // CallLeaf is pure
809     RC_LEAF = 0                 // null value:  no flags set
810   };
811 
812   // merge in all memory slices from new_mem, along the given path
813   void merge_memory(Node* new_mem, Node* region, int new_path);
814   void make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize = false);
815 
816   // Helper functions to build synchronizations
817   int next_monitor();
818   Node* insert_mem_bar(int opcode, Node* precedent = nullptr);
819   Node* insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent = nullptr);
820   // Optional 'precedent' is appended as an extra edge, to force ordering.
821   FastLockNode* shared_lock(Node* obj);
822   void shared_unlock(Node* box, Node* obj);
823 
824   // helper functions for the fast path/slow path idioms
825   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);
826 
827   // Generate an instance-of idiom.  Used by both the instance-of bytecode
828   // and the reflective instance-of call.
829   Node* gen_instanceof(Node *subobj, Node* superkls, bool safe_for_replace = false);
830 
831   // Generate a check-cast idiom.  Used by both the check-cast bytecode
832   // and the array-store bytecode
833   Node* gen_checkcast(Node *subobj, Node* superkls, Node** failure_control = nullptr,
834                       SafePointNode** new_cast_failure_map = nullptr, bool null_free = false,
835                       bool maybe_larval = false);
836 
837   // Inline types
838   Node* mark_word_test(Node* obj, uintptr_t mask_val, bool eq, bool check_lock = true);
839   Node* inline_type_test(Node* obj, bool is_inline = true);
840   Node* flat_array_test(Node* array_or_klass, bool flat = true);
841   Node* null_free_array_test(Node* array, bool null_free = true);
842   Node* null_free_atomic_array_test(Node* array, ciInlineKlass* vk);
843   Node* inline_array_null_guard(Node* ary, Node* val, int nargs, bool safe_for_replace = false);
844 
845   Node* gen_subtype_check(Node* obj, Node* superklass);
846 
847   // Exact type check used for predicted calls and casts.
848   // Rewrites (*casted_receiver) to be casted to the stronger type.
849   // (Caller is responsible for doing replace_in_map.)
850   Node* type_check_receiver(Node* receiver, ciKlass* klass, float prob,
851                             Node* *casted_receiver);
852   Node* type_check(Node* recv_klass, const TypeKlassPtr* tklass, float prob);
853 
854   // Inexact type check used for predicted calls.
855   Node* subtype_check_receiver(Node* receiver, ciKlass* klass,
856                                Node** casted_receiver);
857 
858   // implementation of object creation
859   Node* set_output_for_allocation(AllocateNode* alloc,
860                                   const TypeOopPtr* oop_type,
861                                   bool deoptimize_on_exception=false);
862   Node* get_layout_helper(Node* klass_node, jint& constant_value);
863   Node* new_instance(Node* klass_node,
864                      Node* slow_test = nullptr,
865                      Node* *return_size_val = nullptr,
866                      bool deoptimize_on_exception = false,
867                      InlineTypeNode* inline_type_node = nullptr);
868   Node* new_array(Node* klass_node, Node* count_val, int nargs,
869                   Node* *return_size_val = nullptr,
870                   bool deoptimize_on_exception = false,
871                   Node* init_val = nullptr);
872 
873   // java.lang.String helpers
874   Node* load_String_length(Node* str, bool set_ctrl);
875   Node* load_String_value(Node* str, bool set_ctrl);
876   Node* load_String_coder(Node* str, bool set_ctrl);
877   void store_String_value(Node* str, Node* value);
878   void store_String_coder(Node* str, Node* value);
879   Node* capture_memory(const TypePtr* src_type, const TypePtr* dst_type);
880   Node* compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count);
881   void inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count);
882   void inflate_string_slow(Node* src, Node* dst, Node* start, Node* count);
883 
884   // Handy for making control flow
885   IfNode* create_and_map_if(Node* ctrl, Node* tst, float prob, float cnt) {
886     IfNode* iff = new IfNode(ctrl, tst, prob, cnt);// New IfNode's
887     _gvn.set_type(iff, iff->Value(&_gvn)); // Value may be known at parse-time
888     // Place 'if' on worklist if it will be in graph
889     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later
890     return iff;
891   }
892 
893   IfNode* create_and_xform_if(Node* ctrl, Node* tst, float prob, float cnt) {
894     IfNode* iff = new IfNode(ctrl, tst, prob, cnt);// New IfNode's
895     _gvn.transform(iff);                           // Value may be known at parse-time
896     // Place 'if' on worklist if it will be in graph
897     if (!tst->is_Con())  record_for_igvn(iff);     // Range-check and Null-check removal is later
898     return iff;
899   }
900 
901   void add_parse_predicates(int nargs = 0);
902   void add_parse_predicate(Deoptimization::DeoptReason reason, int nargs);
903 
904   Node* make_constant_from_field(ciField* field, Node* obj);
905   Node* load_mirror_from_klass(Node* klass);
906 
907   // Vector API support (implemented in vectorIntrinsics.cpp)
908   Node* box_vector(Node* in, const TypeInstPtr* vbox_type, BasicType elem_bt, int num_elem, bool deoptimize_on_exception = false);
909   Node* unbox_vector(Node* in, const TypeInstPtr* vbox_type, BasicType elem_bt, int num_elem);
910   Node* vector_shift_count(Node* cnt, int shift_op, BasicType bt, int num_elem);
911 
912   // Helper class to support reverting to a previous parsing state.
913   // When an intrinsic makes changes before bailing out, it's necessary to restore the graph
914   // as it was. See JDK-8359344 for what can happen wrong. It's also not always possible to
915   // bailout before making changes because the bailing out decision might depend on new nodes
916   // (their types, for instance).
917   //
918   // So, if an intrinsic might cause this situation, one must start by saving the state in a
919   // SavedState by constructing it, and the state will be restored on destruction. If the
920   // intrinsic is not bailing out, one need to call discard to prevent restoring the old state.
921   class SavedState : public StackObj {
922     GraphKit* _kit;
923     int _sp;
924     JVMState* _jvms;
925     SafePointNode* _map;
926     Unique_Node_List _ctrl_succ;
927     bool _discarded;
928 
929   public:
930     SavedState(GraphKit*);
931     ~SavedState();
932     void discard();
933   };
934 };
935 
936 // Helper class to support building of control flow branches. Upon
937 // creation the map and sp at bci are cloned and restored upon de-
938 // struction. Typical use:
939 //
940 // { PreserveJVMState pjvms(this);
941 //   // code of new branch
942 // }
943 // // here the JVM state at bci is established
944 
945 class PreserveJVMState: public StackObj {
946  protected:
947   GraphKit*      _kit;
948 #ifdef ASSERT
949   int            _block;  // PO of current block, if a Parse
950   int            _bci;
951 #endif
952   SafePointNode* _map;
953   uint           _sp;
954 
955  public:
956   PreserveJVMState(GraphKit* kit, bool clone_map = true);
957   ~PreserveJVMState();
958 };
959 
960 // Helper class to build cutouts of the form if (p) ; else {x...}.
961 // The code {x...} must not fall through.
962 // The kit's main flow of control is set to the "then" continuation of if(p).
963 class BuildCutout: public PreserveJVMState {
964  public:
965   BuildCutout(GraphKit* kit, Node* p, float prob, float cnt = COUNT_UNKNOWN);
966   ~BuildCutout();
967 };
968 
969 // Helper class to preserve the original _reexecute bit and _sp and restore
970 // them back
971 class PreserveReexecuteState: public StackObj {
972  protected:
973   GraphKit*                 _kit;
974   uint                      _sp;
975   JVMState::ReexecuteState  _reexecute;
976 
977  public:
978   PreserveReexecuteState(GraphKit* kit);
979   ~PreserveReexecuteState();
980 };
981 
982 #endif // SHARE_OPTO_GRAPHKIT_HPP