source: asp3_tinet_ecnl_rx/trunk/musl-1.1.18/src/math/coshf.c@ 337

Last change on this file since 337 was 337, checked in by coas-nagasima, 6 years ago

ASP3版ECNLを追加
  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/x-csrc;charset=UTF-8
File size: 492 bytes
Line 
1#include "libm.h"
2
3float coshf(float x)
4{
5 union {float f; uint32_t i;} u = {.f = x};
6 uint32_t w;
7 float t;
8
9 /* |x| */
10 u.i &= 0x7fffffff;
11 x = u.f;
12 w = u.i;
13
14 /* |x| < log(2) */
15 if (w < 0x3f317217) {
16 if (w < 0x3f800000 - (12<<23)) {
17 FORCE_EVAL(x + 0x1p120f);
18 return 1;
19 }
20 t = expm1f(x);
21 return 1 + t*t/(2*(1+t));
22 }
23
24 /* |x| < log(FLT_MAX) */
25 if (w < 0x42b17217) {
26 t = expf(x);
27 return 0.5f*(t + 1/t);
28 }
29
30 /* |x| > log(FLT_MAX) or nan */
31 t = __expo2f(x);
32 return t;
33}
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