| 0,0 → 1,29 |
|---|
| /* |
| * Written 2005 by Gregory W. Chicares <chicares@cox.net>. |
| * Adapted to float by 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 exp() 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" |
| |
| float expm1f (float x) |
| { |
| if (fabsf(x) < LOGE2L) |
| { |
| x *= LOG2EL; |
| __asm__("f2xm1" : "=t" (x) : "0" (x)); |
| return x; |
| } |
| else |
| return expf(x) - 1.0F; |
| } |