ACE/ace/OS_NS_math.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file   OS_NS_math.h
   6  *
   7  *  @author Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
   8  *  @author Jesper S. M|ller<stophph@diku.dk>
   9  *  @author and a cast of thousands...
  10  *
  11  *  Originally in OS.h.
  12  */
  13 //=============================================================================
  14
  15 #ifndef ACE_OS_NS_MATH_H
  16 # define ACE_OS_NS_MATH_H
  17
  18 # include /**/ "ace/pre.h"
  19
  20 # include "ace/config-all.h"
  21
  22 # if !defined (ACE_LACKS_PRAGMA_ONCE)
  23 #  pragma once
  24 # endif /* ACE_LACKS_PRAGMA_ONCE */
  25
  26 #include "ace/os_include/os_math.h"
  27
  28 #include /**/ "ace/ACE_export.h"
  29
  30 #if defined (ACE_EXPORT_MACRO)
  31 #  undef ACE_EXPORT_MACRO
  32 #endif
  33 #define ACE_EXPORT_MACRO ACE_Export
  34
  35
  36 /*
  37  * We inline and undef some functions that may be implemented
  38  * as macros on some platforms. This way macro definitions will
  39  * be usable later as there is no way to save the macro definition
  40  * using the pre-processor.
  41  */
  42 inline double ace_log2_helper (double x)
  43 {
  44 #if defined (log2)
  45   return log2 (x);
  46 #undef log2
  47 #else
  48 #  if !defined (ACE_LACKS_LOG2)
  49   return ACE_STD_NAMESPACE::log2 (x);
  50 #  else
  51   /*
  52     ==================================================================
  53
  54                 log (x)
  55                    k
  56       log (x) = -------
  57          b      log (b)
  58                    k
  59
  60     meaning the binary logarithm of x using the natural logarithm, for
  61     example, is:
  62
  63
  64                 log (x)
  65                    e
  66       log (x) = -------
  67          2      log (2)
  68                    e
  69
  70     ==================================================================
  71    */
  72
  73   // Precomputed value of 1/log(2.0).  Saves an expensive division and
  74   // computing log(2.0) in each call.
  75   double const _1_ln2 = 1.442695040888963407359924681002;
  76
  77   return log (x) * _1_ln2;
  78 #  endif /* !ACE_LACKS_LOG2 */
  79 #endif /* defined (log2) */
  80 }
  81
  82
  83 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  84
  85 namespace ACE_OS
  86 {
  87   /// This method computes the largest integral value not greater than x.
  88   template <typename T>
  89   inline
  90   T floor (T x)
  91   {
  92     return ACE_STD_NAMESPACE::floor (x);
  93   }
  94
  95 #if defined (ACE_HAS_WINCE)
  96   /// Windows CE has an intrinsic floor for float
  97   template <>
  98   inline
  99   float floor (float x)
 100   {
 101     return ACE_STD_NAMESPACE::floorf (x);
 102   }
 103 #endif
 104
 105   /// This method computes the smallest integral value not less than x.
 106   template <typename T>
 107   inline
 108   T ceil (T x)
 109   {
 110     return ACE_STD_NAMESPACE::ceil (x);
 111   }
 112
 113 #if defined (ACE_HAS_WINCE)
 114   /// Windows CE has an intrinsic ceil for float
 115   template <>
 116   inline
 117   float ceil (float x)
 118   {
 119     return ACE_STD_NAMESPACE::ceilf (x);
 120   }
 121 #endif
 122
 123   /// This method computes the base-2 logarithm of x.
 124   ACE_NAMESPACE_INLINE_FUNCTION
 125   double log2 (double x);
 126
 127 } /* namespace ACE_OS */
 128
 129 ACE_END_VERSIONED_NAMESPACE_DECL
 130
 131 # if defined (ACE_HAS_INLINED_OSCALLS)
 132 #   if defined (ACE_INLINE)
 133 #     undef ACE_INLINE
 134 #   endif /* ACE_INLINE */
 135 #   define ACE_INLINE inline
 136 #   include "ace/OS_NS_math.inl"
 137 # endif /* ACE_HAS_INLINED_OSCALLS */
 138
 139 # include /**/ "ace/post.h"
 140 #endif /* ACE_OS_NS_MATH_H */