1 /*
   2  * Copyright (c) 1997, 2020, 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
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  24 
  25 #ifndef SHARE_CODE_PCDESC_HPP
  26 #define SHARE_CODE_PCDESC_HPP
  27 
  28 
  29 // PcDescs map a physical PC (given as offset from start of nmethod) to
  30 // the corresponding source scope and byte code index.
  31 
  32 class CompiledMethod;
  33 
  34 class PcDesc {
  35   friend class VMStructs;
  36  private:
  37   int _pc_offset;           // offset from start of nmethod
  38   int _scope_decode_offset; // offset for scope in nmethod
  39   int _obj_decode_offset;
  40 
  41   enum {
  42     PCDESC_reexecute               = 1 << 0,
  43     PCDESC_is_method_handle_invoke = 1 << 1,
  44     PCDESC_return_oop              = 1 << 2,
  45     PCDESC_rethrow_exception       = 1 << 3,
  46     PCDESC_not_global_escape_in_scope = 1 << 4,
  47     PCDESC_arg_escape              = 1 << 5
  48   };
  49 
  50   int _flags;
  51 
  52   void set_flag(int mask, bool z) {
  53     _flags = z ? (_flags | mask) : (_flags & ~mask);
  54   }
  55 
  56  public:
  57   int pc_offset() const           { return _pc_offset;   }
  58   int scope_decode_offset() const { return _scope_decode_offset; }
  59   int obj_decode_offset() const   { return _obj_decode_offset; }
  60 
  61   void set_pc_offset(int x)           { _pc_offset           = x; }
  62   void set_scope_decode_offset(int x) { _scope_decode_offset = x; }
  63   void set_obj_decode_offset(int x)   { _obj_decode_offset   = x; }
  64 
  65   // Constructor (only used for static in nmethod.cpp)
  66   // Also used by ScopeDesc::sender()]
  67   PcDesc(int pc_offset, int scope_decode_offset, int obj_decode_offset);
  68 
  69   enum {
  70     // upper and lower exclusive limits real offsets:
  71     lower_offset_limit = -1,
  72     upper_offset_limit = (unsigned int)-1 >> 1
  73   };
  74 
  75   // Flags
  76   bool     rethrow_exception()              const { return (_flags & PCDESC_rethrow_exception) != 0; }
  77   void set_rethrow_exception(bool z)              { set_flag(PCDESC_rethrow_exception, z); }
  78   bool     should_reexecute()              const { return (_flags & PCDESC_reexecute) != 0; }
  79   void set_should_reexecute(bool z)              { set_flag(PCDESC_reexecute, z); }
  80 
  81   // Does pd refer to the same information as pd?
  82   bool is_same_info(const PcDesc* pd) {
  83     return _scope_decode_offset == pd->_scope_decode_offset &&
  84       _obj_decode_offset == pd->_obj_decode_offset &&
  85       _flags == pd->_flags;
  86   }
  87 
  88   bool     is_method_handle_invoke()       const { return (_flags & PCDESC_is_method_handle_invoke) != 0;     }
  89   void set_is_method_handle_invoke(bool z)       { set_flag(PCDESC_is_method_handle_invoke, z); }
  90 
  91   bool     return_oop()                    const { return (_flags & PCDESC_return_oop) != 0;     }
  92   void set_return_oop(bool z)                    { set_flag(PCDESC_return_oop, z); }
  93 
  94   // Indicates if there are objects in scope that, based on escape analysis, are local to the
  95   // compiled method or local to the current thread.
  96   bool     not_global_escape_in_scope()    const { return (_flags & PCDESC_not_global_escape_in_scope) != 0; }
  97   void set_not_global_escape_in_scope(bool z)    { set_flag(PCDESC_not_global_escape_in_scope, z); }
  98 
  99   // Indicates if this pc descriptor is at a call site where objects that do not escape the
 100   // current thread are passed as arguments.
 101   bool     arg_escape()                    const { return (_flags & PCDESC_arg_escape) != 0; }
 102   void set_arg_escape(bool z)                    { set_flag(PCDESC_arg_escape, z); }
 103 
 104   // Returns the real pc
 105   address real_pc(const CompiledMethod* code) const;
 106 
 107   void print(CompiledMethod* code) { print_on(tty, code); }
 108   void print_on(outputStream* st, CompiledMethod* code);
 109   bool verify(CompiledMethod* code);
 110 };
 111 
 112 #endif // SHARE_CODE_PCDESC_HPP