0,0 → 1,63 |
/* ef_sinh.c -- float version of e_sinh.c. |
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
*/ |
|
/* |
* ==================================================== |
* 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 "fdlibm.h" |
|
#ifdef __STDC__ |
static const float one = 1.0, shuge = 1.0e37; |
#else |
static float one = 1.0, shuge = 1.0e37; |
#endif |
|
#ifdef __STDC__ |
float __ieee754_sinhf(float x) |
#else |
float __ieee754_sinhf(x) |
float x; |
#endif |
{ |
float t,w,h; |
__int32_t ix,jx; |
|
GET_FLOAT_WORD(jx,x); |
ix = jx&0x7fffffff; |
|
/* x is INF or NaN */ |
if(!FLT_UWORD_IS_FINITE(ix)) return x+x; |
|
h = 0.5; |
if (jx<0) h = -h; |
/* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ |
if (ix < 0x41b00000) { /* |x|<22 */ |
if (ix<0x31800000) /* |x|<2**-28 */ |
if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ |
t = expm1f(fabsf(x)); |
if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one)); |
return h*(t+t/(t+one)); |
} |
|
/* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ |
if (ix<=FLT_UWORD_LOG_MAX) return h*__ieee754_expf(fabsf(x)); |
|
/* |x| in [log(maxdouble), overflowthresold] */ |
if (ix<=FLT_UWORD_LOG_2MAX) { |
w = __ieee754_expf((float)0.5*fabsf(x)); |
t = h*w; |
return t*w; |
} |
|
/* |x| > overflowthresold, sinh(x) overflow */ |
return x*shuge; |
} |