1 /*

     2  * Copyright 1997-2005 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 class StackValue : public ResourceObj {

    26  private:

    27   BasicType _type;

    28   intptr_t  _i; // Blank java stack slot value

    29   Handle    _o; // Java stack slot value interpreted as a Handle

    30  public:

    31 

    32   StackValue(intptr_t value) {

    33     _type  = T_INT;

    34     _i     = value;

    35   }

    36 

    37   StackValue(Handle value) {

    38     _type    = T_OBJECT;

    39     _o       = value;

    40   }

    41 

    42   StackValue() {

    43     _type   = T_CONFLICT;

    44     _i      = 0;

    45   }

    46 

    47   // Only used during deopt- preserve object type.

    48   StackValue(intptr_t o, BasicType t) {

    49     assert(t == T_OBJECT, "should not be used");

    50     _type   = t;

    51     _i      = o;

    52   }

    53 

    54   Handle get_obj() const {

    55     assert(type() == T_OBJECT, "type check");

    56     return _o;

    57   }

    58 

    59   void set_obj(Handle value) {

    60     assert(type() == T_OBJECT, "type check");

    61     _o = value;

    62   }

    63 

    64   intptr_t get_int() const {

    65     assert(type() == T_INT, "type check");

    66     return _i;

    67   }

    68 

    69   // For special case in deopt.

    70   intptr_t get_int(BasicType t) const {

    71     assert(t == T_OBJECT && type() == T_OBJECT, "type check");

    72     return _i;

    73   }

    74 

    75   void set_int(intptr_t value) {

    76     assert(type() == T_INT, "type check");

    77     _i = value;

    78   }

    79 

    80   BasicType type() const { return  _type; }

    81 

    82   bool equal(StackValue *value) {

    83     if (_type != value->_type) return false;

    84     if (_type == T_OBJECT)

    85       return (_o == value->_o);

    86     else {

    87       assert(_type == T_INT, "sanity check");

    88       // [phh] compare only low addressed portions of intptr_t slots

    89       return (*(int *)&_i == *(int *)&value->_i);

    90     }

    91   }

    92 

    93   static StackValue* create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);

    94   static BasicLock*  resolve_monitor_lock(const frame* fr, Location location);

    95 

    96 #ifndef PRODUCT

    97  public:

    98   // Printing

    99   void print_on(outputStream* st) const;

   100 #endif

   101 };