1 /*
   2  * Copyright (c) 1999, 2006, 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 // ciCallProfile
  26 //
  27 // This class is used to determine the frequently called method
  28 // at some call site
  29 class ciCallProfile : StackObj {
  30 private:
  31   // Fields are initialized directly by ciMethod::call_profile_at_bci.
  32   friend class ciMethod;
  33 
  34   enum { MorphismLimit = 2 }; // Max call site's morphism we care about
  35   int  _limit;                // number of receivers have been determined
  36   int  _morphism;             // determined call site's morphism
  37   int  _count;                // # times has this call been executed
  38   int  _receiver_count[MorphismLimit + 1]; // # times receivers have been seen
  39   ciMethod* _method[MorphismLimit + 1];    // receivers methods
  40   ciKlass*  _receiver[MorphismLimit + 1];  // receivers (exact)
  41 
  42   ciCallProfile() {
  43     _limit = 0;
  44     _morphism    = 0;
  45     _count = -1;
  46     _receiver_count[0] = -1;
  47     _method[0]   = NULL;
  48     _receiver[0] = NULL;
  49   }
  50 
  51   void add_receiver(ciKlass* receiver, int receiver_count);
  52 
  53 public:
  54   // Note:  The following predicates return false for invalid profiles:
  55   bool      has_receiver(int i) { return _limit > i; }
  56   int       morphism()          { return _morphism; }
  57 
  58   int       count()             { return _count; }
  59   int       receiver_count(int i)  {
  60     assert(i < _limit, "out of Call Profile MorphismLimit");
  61     return _receiver_count[i];
  62   }
  63   float     receiver_prob(int i)  {
  64     assert(i < _limit, "out of Call Profile MorphismLimit");
  65     return (float)_receiver_count[i]/(float)_count;
  66   }
  67   ciMethod* method(int i)          {
  68     assert(i < _limit, "out of Call Profile MorphismLimit");
  69     return _method[i];
  70   }
  71   ciKlass*  receiver(int i)        {
  72     assert(i < _limit, "out of Call Profile MorphismLimit");
  73     return _receiver[i];
  74   }
  75 };