1 /*
   2  * Copyright (c) 2017, 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_VM_UTILITIES_TRAITS_INTEGER_HPP
  26 #define SHARE_VM_UTILITIES_TRAITS_INTEGER_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 
  30 namespace IntegerTypeImpl {
  31   template <size_t size>
  32   struct SignedType: AllStatic {};
  33 
  34   template <>
  35   struct SignedType<sizeof(int64_t)>: AllStatic {
  36     typedef int64_t type;
  37   };
  38 
  39   template <>
  40   struct SignedType<sizeof(int32_t)>: AllStatic {
  41     typedef int32_t type;
  42   };
  43 
  44   template <>
  45   struct SignedType<sizeof(int16_t)>: AllStatic {
  46     typedef int16_t type;
  47   };
  48 
  49   template <>
  50   struct SignedType<sizeof(int8_t)>: AllStatic {
  51     typedef signed char type;
  52   };
  53 
  54   template <size_t size>
  55   struct UnsignedType: AllStatic {};
  56 
  57   template <>
  58   struct UnsignedType<sizeof(uint64_t)>: AllStatic {
  59     typedef uint64_t type;
  60   };
  61 
  62   template <>
  63   struct UnsignedType<sizeof(uint32_t)>: AllStatic {
  64     typedef uint32_t type;
  65   };
  66 
  67   template <>
  68   struct UnsignedType<sizeof(uint16_t)>: AllStatic {
  69     typedef uint16_t type;
  70   };
  71 
  72   template <>
  73   struct UnsignedType<sizeof(uint8_t)>: AllStatic {
  74     typedef unsigned char type;
  75   };
  76 }
  77 
  78 template <typename T>
  79 struct IsPointerSize: AllStatic {
  80   enum {
  81     value = sizeof(T) == sizeof(void*)
  82   };
  83 };
  84 
  85 template <typename T>
  86 struct IntegerType: AllStatic {
  87   typedef typename IntegerTypeImpl::SignedType<sizeof(T)>::type signed_type;
  88   typedef typename IntegerTypeImpl::UnsignedType<sizeof(T)>::type unsigned_type;
  89 
  90   static signed_type cast_to_signed(T val) {
  91     return *(signed_type*)&val;
  92   }
  93 
  94   static T cast_from_signed(signed_type val) {
  95     return *(T*)&val;
  96   }
  97 
  98   static unsigned_type cast_to_unsigned(T val) {
  99     return *(unsigned_type*)&val;
 100   }
 101 
 102   static T cast_from_unsigned(unsigned_type val) {
 103     return *(T*)&val;
 104   }
 105 };
 106 
 107 #endif // SHARE_VM_UTILITIES_TRAITS_INTEGER_HPP