/*
* Written 2005 by Gregory W. Chicares <chicares@cox.net> with
* help from Danny Smith. dannysmith@users.sourceforge.net>.
* Public domain.
*
* F2XM1's input is constrained to (-1, +1), so the domain of
* 'x * LOG2EL' is (-LOGE2L, +LOGE2L). Outside that domain,
* delegating to expl() handles C99 7.12.6.3/2 range errors.
*
* Constants from moshier.net, file cephes/ldouble/constl.c,
* are used instead of M_LN2 and M_LOG2E, which would not be
* visible with 'gcc std=c99'. The use of these extended precision
* constants also allows gcc to replace them with x87 opcodes.
*/
#include <math.h> /* expl() */
#include "cephes_mconf.h"
long double expm1l (long double x)
{
if (fabsl(x) < LOGE2L)
{
x *= LOG2EL;
__asm__("f2xm1" : "=t" (x) : "0" (x));
return x;
}
else
return expl(x) - 1.0L;
}