src/math/scalbnl.c

   1 #include "libm.h"
   2
   3 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4 long double scalbnl(long double x, int n)
   5 {
   6         return scalbn(x, n);
   7 }
   8 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
   9 long double scalbnl(long double x, int n)
  10 {
  11         union ldshape u;
  12
  13         if (n > 16383) {
  14                 x *= 0x1p16383L;
  15                 n -= 16383;
  16                 if (n > 16383) {
  17                         x *= 0x1p16383L;
  18                         n -= 16383;
  19                         if (n > 16383)
  20                                 n = 16383;
  21                 }
  22         } else if (n < -16382) {
  23                 x *= 0x1p-16382L * 0x1p113L;
  24                 n += 16382 - 113;
  25                 if (n < -16382) {
  26                         x *= 0x1p-16382L * 0x1p113L;
  27                         n += 16382 - 113;
  28                         if (n < -16382)
  29                                 n = -16382;
  30                 }
  31         }
  32         u.f = 1.0;
  33         u.i.se = 0x3fff + n;
  34         return x * u.f;
  35 }
  36 #endif