fusl/src/math/scalbnl.c

#include "libm.h"

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double scalbnl(long double x, int n) {
  return scalbn(x, n);
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
long double scalbnl(long double x, int n) {
  union ldshape u;

  if (n > 16383) {
    x *= 0x1p16383L;
    n -= 16383;
    if (n > 16383) {
      x *= 0x1p16383L;
      n -= 16383;
      if (n > 16383)
        n = 16383;
    }
  } else if (n < -16382) {
    x *= 0x1p-16382L;
    n += 16382;
    if (n < -16382) {
      x *= 0x1p-16382L;
      n += 16382;
      if (n < -16382)
        n = -16382;
    }
  }
  u.f = 1.0;
  u.i.se = 0x3fff + n;
  return x * u.f;
}
#endif