jdk8-mips64-public/hotspot: src/share/vm/ci/ciConstant.hpp@edb5ab0f3fe5

8001107: @Stable annotation for constant folding of lazily evaluated variables
Reviewed-by: rbackman, twisti, kvn
Contributed-by: john.r.rose@oracle.com, vladimir.x.ivanov@oracle.com

     1 /*

     2  * Copyright (c) 1999, 2011, 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  */

    25 #ifndef SHARE_VM_CI_CICONSTANT_HPP

    26 #define SHARE_VM_CI_CICONSTANT_HPP

    28 #include "ci/ciClassList.hpp"

    29 #include "ci/ciNullObject.hpp"

    31 // ciConstant

    32 //

    33 // This class represents a constant value.

    34 class ciConstant VALUE_OBJ_CLASS_SPEC {

    35   friend class VMStructs;

    36 private:

    37   friend class ciEnv;

    38   friend class ciField;

    40   BasicType _type;

    41   union {

    42     jint      _int;

    43     jlong     _long;

    44     jfloat    _float;

    45     jdouble   _double;

    46     ciObject* _object;

    47   } _value;

    49 public:

    51   ciConstant() {

    52     _type = T_ILLEGAL; _value._long = -1;

    53   }

    54   ciConstant(BasicType type, jint value) {

    55     assert(type != T_LONG && type != T_DOUBLE && type != T_FLOAT,

    56            "using the wrong ciConstant constructor");

    57     _type = type; _value._int = value;

    58   }

    59   ciConstant(jlong value) {

    60     _type = T_LONG; _value._long = value;

    61   }

    62   ciConstant(jfloat value) {

    63     _type = T_FLOAT; _value._float = value;

    64   }

    65   ciConstant(jdouble value) {

    66     _type = T_DOUBLE; _value._double = value;

    67   }

    68   ciConstant(BasicType type, ciObject* p) {

    69     _type = type; _value._object = p;

    70   }

    72   BasicType basic_type() const { return _type; }

    74   jboolean  as_boolean() {

    75     assert(basic_type() == T_BOOLEAN, "wrong type");

    76     return (jboolean)_value._int;

    77   }

    78   jchar     as_char() {

    79     assert(basic_type() == T_CHAR, "wrong type");

    80     return (jchar)_value._int;

    81   }

    82   jbyte     as_byte() {

    83     assert(basic_type() == T_BYTE, "wrong type");

    84     return (jbyte)_value._int;

    85   }

    86   jshort    as_short() {

    87     assert(basic_type() == T_SHORT, "wrong type");

    88     return (jshort)_value._int;

    89   }

    90   jint      as_int() {

    91     assert(basic_type() == T_BOOLEAN || basic_type() == T_CHAR  ||

    92            basic_type() == T_BYTE    || basic_type() == T_SHORT ||

    93            basic_type() == T_INT, "wrong type");

    94     return _value._int;

    95   }

    96   jlong     as_long() {

    97     assert(basic_type() == T_LONG, "wrong type");

    98     return _value._long;

    99   }

   100   jfloat    as_float() {

   101     assert(basic_type() == T_FLOAT, "wrong type");

   102     return _value._float;

   103   }

   104   jdouble   as_double() {

   105     assert(basic_type() == T_DOUBLE, "wrong type");

   106     return _value._double;

   107   }

   108   ciObject* as_object() const {

   109     assert(basic_type() == T_OBJECT || basic_type() == T_ARRAY, "wrong type");

   110     return _value._object;

   111   }

   113   bool      is_null_or_zero() const {

   114     if (!is_java_primitive(basic_type())) {

   115       return as_object()->is_null_object();

   116     } else if (type2size[basic_type()] == 1) {

   117       // treat float bits as int, to avoid comparison with -0 and NaN

   118       return (_value._int == 0);

   119     } else if (type2size[basic_type()] == 2) {

   120       // treat double bits as long, to avoid comparison with -0 and NaN

   121       return (_value._long == 0);

   122     } else {

   123       return false;

   124     }

   125   }

   127   // Debugging output

   128   void print();

   129 };

   131 #endif // SHARE_VM_CI_CICONSTANT_HPP

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/ci/ciConstant.hpp@edb5ab0f3fe5

src/share/vm/ci/ciConstant.hpp