cosmopolitan/libc/math/scalbnl.c

37 lines
679 B
C

#include "libc/math/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 * 0x1p113L;
n += 16382 - 113;
if (n < -16382) {
x *= 0x1p-16382L * 0x1p113L;
n += 16382 - 113;
if (n < -16382)
n = -16382;
}
}
u.f = 1.0;
u.i.se = 0x3fff + n;
return x * u.f;
}
#endif