mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 12:11:10 +00:00
0ac5ae2335
libm is now somewhat integrated with gcc's -ffinite-math-only option and lots of the wrapper functions have been optimized.
64 lines
1.6 KiB
C
64 lines
1.6 KiB
C
/* e_coshf.c -- float version of e_cosh.c.
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
|
* Optimizations by Ulrich Drepper <drepper@gmail.com>, 2011
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*/
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
static const float huge = 1.0e30;
|
|
static const float one = 1.0, half=0.5;
|
|
|
|
float
|
|
__ieee754_coshf (float x)
|
|
{
|
|
float t,w;
|
|
int32_t ix;
|
|
|
|
GET_FLOAT_WORD(ix,x);
|
|
ix &= 0x7fffffff;
|
|
|
|
/* |x| in [0,22] */
|
|
if (ix < 0x41b00000) {
|
|
/* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
|
|
if(ix<0x3eb17218) {
|
|
t = __expm1f(fabsf(x));
|
|
w = one+t;
|
|
if (ix<0x24000000) return w; /* cosh(tiny) = 1 */
|
|
return one+(t*t)/(w+w);
|
|
}
|
|
|
|
/* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
|
|
t = __ieee754_expf(fabsf(x));
|
|
return half*t+half/t;
|
|
}
|
|
|
|
/* |x| in [22, log(maxdouble)] return half*exp(|x|) */
|
|
if (ix < 0x42b17180) return half*__ieee754_expf(fabsf(x));
|
|
|
|
/* |x| in [log(maxdouble), overflowthresold] */
|
|
if (ix<=0x42b2d4fc) {
|
|
w = __ieee754_expf(half*fabsf(x));
|
|
t = half*w;
|
|
return t*w;
|
|
}
|
|
|
|
/* x is INF or NaN */
|
|
if(ix>=0x7f800000) return x*x;
|
|
|
|
/* |x| > overflowthresold, cosh(x) overflow */
|
|
return huge*huge;
|
|
}
|
|
strong_alias (__ieee754_coshf, __coshf_finite)
|