mdw@git.distorted.org.uk Git - mLib/blob - utils/maths.h

   1 /* -*-c-*-
   2  *
   3  * Mathematical utilities
   4  *
   5  * (c) 2023 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU Library General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  20  * License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib.  If not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  25  * USA.
  26  */
  27
  28 #ifndef MLIB_MATHS_H
  29 #define MLIB_MATHS_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <math.h>
  38
  39 /*----- Macros provided ---------------------------------------------------*/
  40
  41 /* --- @NANP@ --- *
  42  *
  43  * Arguments:   @floatish x@ = a floating-point number (evaluated multiple
  44  *                      times)
  45  *
  46  * Returns:     Nonzero if @x@ is not-a-number.
  47  */
  48
  49 #ifdef isnan
  50 #  define NANP(x) isnan(x)
  51 #else
  52 #  define NANP(x) (!((x) == (x)))
  53 #endif
  54
  55 /* --- @INFP@ --- *
  56  *
  57  * Arguments:   @floatish x@ = a floating-point number (evaluated multiple
  58  *                      times)
  59  *
  60  * Returns:     Nonzero if @x@ is infinite.
  61  */
  62
  63 #ifdef isinf
  64 #  define INFP(x) isinf(x)
  65 #else
  66 #  define INFP(x) ((x) > LDBL_MAX || (x) < -LDBL_MAX)
  67 #endif
  68
  69 /* --- @NEGP@ --- *
  70  *
  71  * Arguments:   @floatish x@ = a floating-point number (evaluated multiple
  72  *                      times)
  73  *
  74  * Returns:     Nonzero if @x@ is negative.  This won't give the right answer
  75  *              for negative zero unless the system provides explicit
  76  *              support.
  77  */
  78
  79 #ifdef signbit
  80 #  define NEGP(x) signbit(x)
  81 #else
  82 #  define NEGP(x) ((x) < 0)
  83 #endif
  84
  85 /*----- That's all, folks -------------------------------------------------*/
  86
  87 #ifdef __cplusplus
  88   }
  89 #endif
  90
  91 #endif