src/math/floorl.c

   1 #include "libm.h"
   2
   3 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4 long double floorl(long double x)
   5 {
   6         return floor(x);
   7 }
   8 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
   9 #if LDBL_MANT_DIG == 64
  10 #define TOINT 0x1p63
  11 #elif LDBL_MANT_DIG == 113
  12 #define TOINT 0x1p112
  13 #endif
  14 long double floorl(long double x)
  15 {
  16         union ldshape u = {x};
  17         int e = u.i.se & 0x7fff;
  18         long double y;
  19
  20         if (e >= 0x3fff+LDBL_MANT_DIG-1 || x == 0)
  21                 return x;
  22         /* y = int(x) - x, where int(x) is an integer neighbor of x */
  23         if (u.i.se >> 15)
  24                 y = x - TOINT + TOINT - x;
  25         else
  26                 y = x + TOINT - TOINT - x;
  27         /* special case because of non-nearest rounding modes */
  28         if (e <= 0x3fff-1) {
  29                 FORCE_EVAL(y);
  30                 return u.i.se >> 15 ? -1 : 0;
  31         }
  32         if (y > 0)
  33                 return x + y - 1;
  34         return x + y;
  35 }
  36 #endif