1 /*
   2  * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_OPTO_CALLGENERATOR_HPP
  26 #define SHARE_OPTO_CALLGENERATOR_HPP
  27 
  28 #include "compiler/compileBroker.hpp"
  29 #include "opto/callnode.hpp"
  30 #include "opto/compile.hpp"
  31 #include "opto/type.hpp"
  32 #include "runtime/deoptimization.hpp"
  33 
  34 //---------------------------CallGenerator-------------------------------------
  35 // The subclasses of this class handle generation of ideal nodes for
  36 // call sites and method entry points.
  37 
  38 class CallGenerator : public ResourceObj {
  39  public:
  40   enum {
  41     xxxunusedxxx
  42   };
  43 
  44  private:
  45   ciMethod*             _method;                // The method being called.
  46 
  47  protected:
  48   CallGenerator(ciMethod* method) : _method(method) {}
  49 
  50  public:
  51   // Accessors
  52   ciMethod*          method() const             { return _method; }
  53 
  54   // is_inline: At least some code implementing the method is copied here.
  55   virtual bool      is_inline() const           { return false; }
  56   // is_intrinsic: There's a method-specific way of generating the inline code.
  57   virtual bool      is_intrinsic() const        { return false; }
  58   // is_parse: Bytecodes implementing the specific method are copied here.
  59   virtual bool      is_parse() const            { return false; }
  60   // is_virtual: The call uses the receiver type to select or check the method.
  61   virtual bool      is_virtual() const          { return false; }
  62   // is_deferred: The decision whether to inline or not is deferred.
  63   virtual bool      is_deferred() const         { return false; }
  64   // is_predicated: Uses an explicit check (predicate).
  65   virtual bool      is_predicated() const       { return false; }
  66   virtual int       predicates_count() const    { return 0; }
  67   // is_trap: Does not return to the caller.  (E.g., uncommon trap.)
  68   virtual bool      is_trap() const             { return false; }
  69   // does_virtual_dispatch: Should try inlining as normal method first.
  70   virtual bool      does_virtual_dispatch() const     { return false; }
  71 
  72   // is_late_inline: supports conversion of call into an inline
  73   virtual bool      is_late_inline() const      { return false; }
  74   // same but for method handle calls
  75   virtual bool      is_mh_late_inline() const   { return false; }
  76   virtual bool      is_string_late_inline() const{ return false; }
  77 
  78   // for method handle calls: have we tried inlinining the call already?
  79   virtual bool      already_attempted() const   { ShouldNotReachHere(); return false; }
  80 
  81   // Replace the call with an inline version of the code
  82   virtual void do_late_inline() { ShouldNotReachHere(); }
  83 
  84   virtual CallStaticJavaNode* call_node() const { ShouldNotReachHere(); return NULL; }
  85 
  86   virtual void set_unique_id(jlong id)          { fatal("unique id only for late inlines"); };
  87   virtual jlong unique_id() const               { fatal("unique id only for late inlines"); return 0; };
  88 
  89   // Note:  It is possible for a CG to be both inline and virtual.
  90   // (The hashCode intrinsic does a vtable check and an inlined fast path.)
  91 
  92   // Utilities:
  93   const TypeFunc*   tf() const;
  94 
  95   // The given jvms has state and arguments for a call to my method.
  96   // Edges after jvms->argoff() carry all (pre-popped) argument values.
  97   //
  98   // Update the map with state and return values (if any) and return it.
  99   // The return values (0, 1, or 2) must be pushed on the map's stack,
 100   // and the sp of the jvms incremented accordingly.
 101   //
 102   // The jvms is returned on success.  Alternatively, a copy of the
 103   // given jvms, suitably updated, may be returned, in which case the
 104   // caller should discard the original jvms.
 105   //
 106   // The non-Parm edges of the returned map will contain updated global state,
 107   // and one or two edges before jvms->sp() will carry any return values.
 108   // Other map edges may contain locals or monitors, and should not
 109   // be changed in meaning.
 110   //
 111   // If the call traps, the returned map must have a control edge of top.
 112   // If the call can throw, the returned map must report has_exceptions().
 113   //
 114   // If the result is NULL, it means that this CallGenerator was unable
 115   // to handle the given call, and another CallGenerator should be consulted.
 116   virtual JVMState* generate(JVMState* jvms) = 0;
 117 
 118   // How to generate a call site that is inlined:
 119   static CallGenerator* for_inline(ciMethod* m, float expected_uses = -1);
 120   // How to generate code for an on-stack replacement handler.
 121   static CallGenerator* for_osr(ciMethod* m, int osr_bci);
 122 
 123   // How to generate vanilla out-of-line call sites:
 124   static CallGenerator* for_direct_call(ciMethod* m, bool separate_io_projs = false);   // static, special
 125   static CallGenerator* for_virtual_call(ciMethod* m, int vtable_index);  // virtual, interface
 126 
 127   static CallGenerator* for_method_handle_call(  JVMState* jvms, ciMethod* caller, ciMethod* callee, bool delayed_forbidden);
 128   static CallGenerator* for_method_handle_inline(JVMState* jvms, ciMethod* caller, ciMethod* callee, bool& input_not_const);
 129 
 130   // How to generate a replace a direct call with an inline version
 131   static CallGenerator* for_late_inline(ciMethod* m, CallGenerator* inline_cg);
 132   static CallGenerator* for_mh_late_inline(ciMethod* caller, ciMethod* callee, bool input_not_const);
 133   static CallGenerator* for_string_late_inline(ciMethod* m, CallGenerator* inline_cg);
 134   static CallGenerator* for_boxing_late_inline(ciMethod* m, CallGenerator* inline_cg);
 135 
 136   // How to make a call but defer the decision whether to inline or not.
 137   static CallGenerator* for_warm_call(WarmCallInfo* ci,
 138                                       CallGenerator* if_cold,
 139                                       CallGenerator* if_hot);
 140 
 141   // How to make a call that optimistically assumes a receiver type:
 142   static CallGenerator* for_predicted_call(ciKlass* predicted_receiver,
 143                                            CallGenerator* if_missed,
 144                                            CallGenerator* if_hit,
 145                                            float hit_prob);
 146 
 147   static CallGenerator* for_guarded_call(ciKlass* predicted_receiver,
 148                                          CallGenerator* if_missed,
 149                                          CallGenerator* if_hit);
 150 
 151   // How to make a call that optimistically assumes a MethodHandle target:
 152   static CallGenerator* for_predicted_dynamic_call(ciMethodHandle* predicted_method_handle,
 153                                                    CallGenerator* if_missed,
 154                                                    CallGenerator* if_hit,
 155                                                    float hit_prob);
 156 
 157   // How to make a call that gives up and goes back to the interpreter:
 158   static CallGenerator* for_uncommon_trap(ciMethod* m,
 159                                           Deoptimization::DeoptReason reason,
 160                                           Deoptimization::DeoptAction action);
 161 
 162   // Registry for intrinsics:
 163   static CallGenerator* for_intrinsic(ciMethod* m);
 164   static void register_intrinsic(ciMethod* m, CallGenerator* cg);
 165   static CallGenerator* for_predicated_intrinsic(CallGenerator* intrinsic,
 166                                                  CallGenerator* cg);
 167   virtual Node* generate_predicate(JVMState* jvms, int predicate) { return NULL; };
 168 
 169   virtual void print_inlining_late(const char* msg) { ShouldNotReachHere(); }
 170 
 171   static void print_inlining(Compile* C, ciMethod* callee, int inline_level, int bci, const char* msg) {
 172     if (C->print_inlining()) {
 173       C->print_inlining(callee, inline_level, bci, msg);
 174     }
 175   }
 176 
 177   static void print_inlining_failure(Compile* C, ciMethod* callee, int inline_level, int bci, const char* msg) {
 178     print_inlining(C, callee, inline_level, bci, msg);
 179     C->log_inline_failure(msg);
 180   }
 181 
 182   static bool is_inlined_method_handle_intrinsic(JVMState* jvms, ciMethod* m);
 183   static bool is_inlined_method_handle_intrinsic(ciMethod* caller, int bci, ciMethod* m);
 184   static bool is_inlined_method_handle_intrinsic(ciMethod* symbolic_info, ciMethod* m);
 185 };
 186 
 187 
 188 //------------------------InlineCallGenerator----------------------------------
 189 class InlineCallGenerator : public CallGenerator {
 190  protected:
 191   InlineCallGenerator(ciMethod* method) : CallGenerator(method) {}
 192 
 193  public:
 194   virtual bool      is_inline() const           { return true; }
 195 };
 196 
 197 
 198 //---------------------------WarmCallInfo--------------------------------------
 199 // A struct to collect information about a given call site.
 200 // Helps sort call sites into "hot", "medium", and "cold".
 201 // Participates in the queueing of "medium" call sites for possible inlining.
 202 class WarmCallInfo : public ResourceObj {
 203  private:
 204 
 205   CallNode*     _call;   // The CallNode which may be inlined.
 206   CallGenerator* _hot_cg;// CG for expanding the call node
 207 
 208   // These are the metrics we use to evaluate call sites:
 209 
 210   float         _count;  // How often do we expect to reach this site?
 211   float         _profit; // How much time do we expect to save by inlining?
 212   float         _work;   // How long do we expect the average call to take?
 213   float         _size;   // How big do we expect the inlined code to be?
 214 
 215   float         _heat;   // Combined score inducing total order on call sites.
 216   WarmCallInfo* _next;   // Next cooler call info in pending queue.
 217 
 218   // Count is the number of times this call site is expected to be executed.
 219   // Large count is favorable for inlining, because the extra compilation
 220   // work will be amortized more completely.
 221 
 222   // Profit is a rough measure of the amount of time we expect to save
 223   // per execution of this site if we inline it.  (1.0 == call overhead)
 224   // Large profit favors inlining.  Negative profit disables inlining.
 225 
 226   // Work is a rough measure of the amount of time a typical out-of-line
 227   // call from this site is expected to take.  (1.0 == call, no-op, return)
 228   // Small work is somewhat favorable for inlining, since methods with
 229   // short "hot" traces are more likely to inline smoothly.
 230 
 231   // Size is the number of graph nodes we expect this method to produce,
 232   // not counting the inlining of any further warm calls it may include.
 233   // Small size favors inlining, since small methods are more likely to
 234   // inline smoothly.  The size is estimated by examining the native code
 235   // if available.  The method bytecodes are also examined, assuming
 236   // empirically observed node counts for each kind of bytecode.
 237 
 238   // Heat is the combined "goodness" of a site's inlining.  If we were
 239   // omniscient, it would be the difference of two sums of future execution
 240   // times of code emitted for this site (amortized across multiple sites if
 241   // sharing applies).  The two sums are for versions of this call site with
 242   // and without inlining.
 243 
 244   // We approximate this mythical quantity by playing with averages,
 245   // rough estimates, and assumptions that history repeats itself.
 246   // The basic formula count * profit is heuristically adjusted
 247   // by looking at the expected compilation and execution times of
 248   // of the inlined call.
 249 
 250   // Note:  Some of these metrics may not be present in the final product,
 251   // but exist in development builds to experiment with inline policy tuning.
 252 
 253   // This heuristic framework does not model well the very significant
 254   // effects of multiple-level inlining.  It is possible to see no immediate
 255   // profit from inlining X->Y, but to get great profit from a subsequent
 256   // inlining X->Y->Z.
 257 
 258   // This framework does not take well into account the problem of N**2 code
 259   // size in a clique of mutually inlinable methods.
 260 
 261   WarmCallInfo*  next() const          { return _next; }
 262   void       set_next(WarmCallInfo* n) { _next = n; }
 263 
 264   static WarmCallInfo _always_hot;
 265   static WarmCallInfo _always_cold;
 266 
 267   // Constructor intitialization of always_hot and always_cold
 268   WarmCallInfo(float c, float p, float w, float s) {
 269     _call = NULL;
 270     _hot_cg = NULL;
 271     _next = NULL;
 272     _count = c;
 273     _profit = p;
 274     _work = w;
 275     _size = s;
 276     _heat = 0;
 277   }
 278 
 279  public:
 280   // Because WarmInfo objects live over the entire lifetime of the
 281   // Compile object, they are allocated into the comp_arena, which
 282   // does not get resource marked or reset during the compile process
 283   void *operator new( size_t x, Compile* C ) throw() { return C->comp_arena()->Amalloc(x); }
 284   void operator delete( void * ) { } // fast deallocation
 285 
 286   static WarmCallInfo* always_hot();
 287   static WarmCallInfo* always_cold();
 288 
 289   WarmCallInfo() {
 290     _call = NULL;
 291     _hot_cg = NULL;
 292     _next = NULL;
 293     _count = _profit = _work = _size = _heat = 0;
 294   }
 295 
 296   CallNode* call() const { return _call; }
 297   float count()    const { return _count; }
 298   float size()     const { return _size; }
 299   float work()     const { return _work; }
 300   float profit()   const { return _profit; }
 301   float heat()     const { return _heat; }
 302 
 303   void set_count(float x)     { _count = x; }
 304   void set_size(float x)      { _size = x; }
 305   void set_work(float x)      { _work = x; }
 306   void set_profit(float x)    { _profit = x; }
 307   void set_heat(float x)      { _heat = x; }
 308 
 309   // Load initial heuristics from profiles, etc.
 310   // The heuristics can be tweaked further by the caller.
 311   void init(JVMState* call_site, ciMethod* call_method, ciCallProfile& profile, float prof_factor);
 312 
 313   static float MAX_VALUE() { return +1.0e10; }
 314   static float MIN_VALUE() { return -1.0e10; }
 315 
 316   float compute_heat() const;
 317 
 318   void set_call(CallNode* call)      { _call = call; }
 319   void set_hot_cg(CallGenerator* cg) { _hot_cg = cg; }
 320 
 321   // Do not queue very hot or very cold calls.
 322   // Make very cold ones out of line immediately.
 323   // Inline very hot ones immediately.
 324   // These queries apply various tunable limits
 325   // to the above metrics in a systematic way.
 326   // Test for coldness before testing for hotness.
 327   bool is_cold() const;
 328   bool is_hot() const;
 329 
 330   // Force a warm call to be hot.  This worklists the call node for inlining.
 331   void make_hot();
 332 
 333   // Force a warm call to be cold.  This worklists the call node for out-of-lining.
 334   void make_cold();
 335 
 336   // A reproducible total ordering, in which heat is the major key.
 337   bool warmer_than(WarmCallInfo* that);
 338 
 339   // List management.  These methods are called with the list head,
 340   // and return the new list head, inserting or removing the receiver.
 341   WarmCallInfo* insert_into(WarmCallInfo* head);
 342   WarmCallInfo* remove_from(WarmCallInfo* head);
 343 
 344 #ifndef PRODUCT
 345   void print() const;
 346   void print_all() const;
 347   int count_all() const;
 348 #endif
 349 };
 350 
 351 #endif // SHARE_OPTO_CALLGENERATOR_HPP