regress/lib/libm/round/round.c

   1 /* $NetBSD$ */
   2
   3 #include <math.h>
   4
   5 /*
   6  * This tests for a bug in the initial implementation where precision
   7  * was lost in an internal substraction, leading to rounding
   8  * into the wrong direction.
   9  */
  10
  11 /* 0.5 - EPSILON */
  12 #define VAL 0x0.7ffffffffffffcp0
  13 #define VALF 0x0.7fffff8p0
  14
  15 int main()
  16 {
  17         double a = VAL, b, c;
  18         float af = VALF, bf, cf;
  19
  20         b = round(a);
  21         bf = roundf(af);
  22         c = round(-a);
  23         cf = roundf(-af);
  24         return (b != 0 || bf != 0 || c != 0 || cf != 0);
  25 }