glibc/sysdeps/ieee754/ldbl-128/e_acoshl.c
Ulrich Drepper 4dbb64174c Update.
2001-07-06  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/unix/sysv/linux/i386/sigaction.c (RESTORE2): Put asm
	explicitly into .text section.

2001-04-16  Jes Sorensen  <jes@linuxcare.com>

	* sysdeps/unix/sysv/linux/ia64/bits/sigcontext.h (struct sigcontext):
	Add 16 longwords reserved for future use to match changes in the
	kernel.

2001-07-03  Jes Sorensen  <jes@trained-monkey.org>

	* sysdeps/ia64/strncpy.S: Call strnlen() when determining the
	string length rather than strlen(). Solves the performance problem
	of doing strlen on a 5MB string when strncpy was called with a
	length argument of 5 bytes.

2001-07-02  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela): Handle
	R_SPARC_UA16 and R_SPARC_UA32.
	* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_rela): Likewise.

2001-07-01  Stephen L Moshier  <moshier@mediaone.net>

	* sysdeps/ieee754/ldbl-96/e_acoshl.c (__ieee754_acoshl):
	acosh(x) = ln(2x) if x > 2^30.
	* sysdeps/ieee754/ldbl-128/e_acoshl.c (__ieee754_acoshl):
	acosh(x) = ln(2x) if x > 2^54.

	* sysdeps/hppa/dl-machine.h (elf_machine_rela): Handle relocs
2001-07-07 22:59:32 +00:00

69 lines
1.8 KiB
C

/* e_acoshl.c -- long double version of e_acosh.c.
* Conversion to long double by Jakub Jelinek, jj@ultra.linux.cz.
*/
/*
* ====================================================
* 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_acoshl(x)
* Method :
* Based on
* acoshl(x) = logl [ x + sqrtl(x*x-1) ]
* we have
* acoshl(x) := logl(x)+ln2, if x is large; else
* acoshl(x) := logl(2x-1/(sqrtl(x*x-1)+x)) if x>2; else
* acoshl(x) := log1pl(t+sqrtl(2.0*t+t*t)); where t=x-1.
*
* Special cases:
* acoshl(x) is NaN with signal if x<1.
* acoshl(NaN) is NaN without signal.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double
#else
static long double
#endif
one = 1.0,
ln2 = 0.6931471805599453094172321214581766L;
#ifdef __STDC__
long double __ieee754_acoshl(long double x)
#else
long double __ieee754_acoshl(x)
long double x;
#endif
{
long double t;
u_int64_t lx;
int64_t hx;
GET_LDOUBLE_WORDS64(hx,lx,x);
if(hx<0x3fff000000000000LL) { /* x < 1 */
return (x-x)/(x-x);
} else if(hx >=0x4035000000000000LL) { /* x > 2**54 */
if(hx >=0x7fff000000000000LL) { /* x is inf of NaN */
return x+x;
} else
return __ieee754_logl(x)+ln2; /* acoshl(huge)=logl(2x) */
} else if(((hx-0x3fff000000000000LL)|lx)==0) {
return 0.0L; /* acosh(1) = 0 */
} else if (hx > 0x4000000000000000LL) { /* 2**28 > x > 2 */
t=x*x;
return __ieee754_logl(2.0L*x-one/(x+__ieee754_sqrtl(t-one)));
} else { /* 1<x<2 */
t = x-one;
return __log1pl(t+__sqrtl(2.0L*t+t*t));
}
}