1 /*
   2  * Copyright (c) 1999, 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_CI_CICONSTANT_HPP
  26 #define SHARE_CI_CICONSTANT_HPP
  27 
  28 #include "ci/ciClassList.hpp"
  29 #include "ci/ciNullObject.hpp"
  30 
  31 // ciConstant
  32 //
  33 // This class represents a constant value.
  34 class ciConstant {
  35   friend class VMStructs;
  36 private:
  37   friend class ciEnv;
  38   friend class ciField;
  39 
  40   BasicType _type;
  41   union {
  42     jint      _int;
  43     jlong     _long;
  44     jfloat    _float;
  45     jdouble   _double;
  46     ciObject* _object;
  47   } _value;
  48 
  49 public:
  50 
  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   }
  71 
  72   BasicType basic_type() const { return _type; }
  73 
  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   }
 112 
 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   }
 126 
 127   bool is_valid() const {
 128     return basic_type() != T_ILLEGAL;
 129   }
 130   // Debugging output
 131   void print();
 132 };
 133 
 134 #endif // SHARE_CI_CICONSTANT_HPP