src/lib/intmath/cmp.h

   1 /* Copyright (c) 2003-2004, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2021, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 /**
   7  * \file cmp.h
   8  *
   9  * \brief Macro definitions for MIN, MAX, and CLAMP.
  10  **/
  11
  12 #ifndef TOR_INTMATH_CMP_H
  13 #define TOR_INTMATH_CMP_H
  14
  15 /** Macros for MIN/MAX.  Never use these when the arguments could have
  16  * side-effects.
  17  * {With GCC extensions we could probably define a safer MIN/MAX.  But
  18  * depending on that safety would be dangerous, since not every platform
  19  * has it.}
  20  **/
  21 #ifndef MAX
  22 #define MAX(a,b) ( ((a)<(b)) ? (b) : (a) )
  23 #endif
  24 #ifndef MIN
  25 #define MIN(a,b) ( ((a)>(b)) ? (b) : (a) )
  26 #endif
  27
  28 /* Return <b>v</b> if it's between <b>min</b> and <b>max</b>.  Otherwise
  29  * return <b>min</b> if <b>v</b> is smaller than <b>min</b>, or <b>max</b> if
  30  * <b>b</b> is larger than <b>max</b>.
  31  *
  32  * Requires that <b>min</b> is no more than <b>max</b>. May evaluate any of
  33  * its arguments more than once! */
  34 #define CLAMP(min,v,max)                        \
  35   ( ((v) < (min)) ? (min) :                     \
  36     ((v) > (max)) ? (max) :                     \
  37     (v) )
  38
  39 /** Give the absolute value of <b>x</b>, independent of its type. */
  40 #define ABS(x) ( ((x)<0) ? -(x) : (x) )
  41
  42 #endif /* !defined(TOR_INTMATH_CMP_H) */