mirror of
git://sourceware.org/git/newlib-cygwin.git
synced 2025-01-15 11:00:04 +08:00
e0b0f63573
* libc/stdlib/mprec.c (ulp, b2d, d2b): changed a few expressions
like x << y-z to the equivalent x << (y-z).
(d2b): changed if statements with assignment to perform the
assignment prior to the if check.
* libc/reent/reent.c: included stdlib.h for "_free_r" prototype.
* libc/unix/getpass.c (getpass): moved "echo" assignment out of if.
* libc/unix/ttyname.c: included string.h for "strcpy" prototype.
* libc/unix/getcwd.c (ISDOT): added parentheses to clarify && and ||
precedence.
* libc/include/sys/unistd.h: added "vfork" prototype (for popen.c).
Added "_execve" prototype (for execl.c, execle.c, execv.c, and
execve.c).
* libc/posix/popen.c (popen): added parentheses to clarify && and ||
precedence.
* libm/math/e_cosh.c (__ieee754_cosh): changed parentheses to
clarify && and || precendence (and to remove pascalism).
* libm/math/e_sinh.c (__ieee754_sinh): Ditto.
* libm/math/s_infconst.c: added another pair of braces to all
initializers for __infinity (need three: for __infinity[1] array,
for union __dmath, and for i[2]).
94 lines
2.4 KiB
C
94 lines
2.4 KiB
C
|
|
/* @(#)e_cosh.c 5.1 93/09/24 */
|
|
/*
|
|
* ====================================================
|
|
* 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.
|
|
* ====================================================
|
|
*/
|
|
|
|
/* __ieee754_cosh(x)
|
|
* Method :
|
|
* mathematically cosh(x) if defined to be (exp(x)+exp(-x))/2
|
|
* 1. Replace x by |x| (cosh(x) = cosh(-x)).
|
|
* 2.
|
|
* [ exp(x) - 1 ]^2
|
|
* 0 <= x <= ln2/2 : cosh(x) := 1 + -------------------
|
|
* 2*exp(x)
|
|
*
|
|
* exp(x) + 1/exp(x)
|
|
* ln2/2 <= x <= 22 : cosh(x) := -------------------
|
|
* 2
|
|
* 22 <= x <= lnovft : cosh(x) := exp(x)/2
|
|
* lnovft <= x <= ln2ovft: cosh(x) := exp(x/2)/2 * exp(x/2)
|
|
* ln2ovft < x : cosh(x) := huge*huge (overflow)
|
|
*
|
|
* Special cases:
|
|
* cosh(x) is |x| if x is +INF, -INF, or NaN.
|
|
* only cosh(0)=1 is exact for finite x.
|
|
*/
|
|
|
|
#include "fdlibm.h"
|
|
|
|
#ifndef _DOUBLE_IS_32BITS
|
|
|
|
#ifdef __STDC__
|
|
static const double one = 1.0, half=0.5, huge = 1.0e300;
|
|
#else
|
|
static double one = 1.0, half=0.5, huge = 1.0e300;
|
|
#endif
|
|
|
|
#ifdef __STDC__
|
|
double __ieee754_cosh(double x)
|
|
#else
|
|
double __ieee754_cosh(x)
|
|
double x;
|
|
#endif
|
|
{
|
|
double t,w;
|
|
__int32_t ix;
|
|
__uint32_t lx;
|
|
|
|
/* High word of |x|. */
|
|
GET_HIGH_WORD(ix,x);
|
|
ix &= 0x7fffffff;
|
|
|
|
/* x is INF or NaN */
|
|
if(ix>=0x7ff00000) return x*x;
|
|
|
|
/* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
|
|
if(ix<0x3fd62e43) {
|
|
t = expm1(fabs(x));
|
|
w = one+t;
|
|
if (ix<0x3c800000) return w; /* cosh(tiny) = 1 */
|
|
return one+(t*t)/(w+w);
|
|
}
|
|
|
|
/* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
|
|
if (ix < 0x40360000) {
|
|
t = __ieee754_exp(fabs(x));
|
|
return half*t+half/t;
|
|
}
|
|
|
|
/* |x| in [22, log(maxdouble)] return half*exp(|x|) */
|
|
if (ix < 0x40862E42) return half*__ieee754_exp(fabs(x));
|
|
|
|
/* |x| in [log(maxdouble), overflowthresold] */
|
|
GET_LOW_WORD(lx,x);
|
|
if (ix<0x408633CE ||
|
|
(ix==0x408633ce && lx<=(__uint32_t)0x8fb9f87d)) {
|
|
w = __ieee754_exp(half*fabs(x));
|
|
t = half*w;
|
|
return t*w;
|
|
}
|
|
|
|
/* |x| > overflowthresold, cosh(x) overflow */
|
|
return huge*huge;
|
|
}
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|