glibc/sysdeps/libm-ieee754/s_tanhl.c
Ulrich Drepper c57abfa735 Update.
1997-03-20 01:49  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/libm-ieee754/s_tanhl.c (__tanhl): Correct handling of
	-inf.

	* Makeconfig: (rpath-link): Add math/ directory.
	(math-objdir): New variable.
	(link-extra-lib): Define to special version when
	$(common-objpfx)!=$(objpfx) to allow libraries outside
	$(common-objpfx) be linked to the application.

	* math/Makefile: Add rules to build and run test programs.
	* math/libm-test.c (_GNU_SOURCE): Define only if still undefined.
	(check_equal): Correct check for error.
	(ceil_test): Fix typo.
	(log_test): Fix typo.
	(floor_test): Fix typo.
	(pow_test): Fix typos.
	(log10_test): Allow slight incorrectness for `log10(e)'.
	(modf_test): New functions to test `modf' et.al.
	(hypot_test): Rewrite test completely.
	Patch partly by Andreas Jaeger.
	* math/test-double.h (__NO_MATH_INLINES): Define only if not
	already defined.
	* math/test-float.h: Likewise.
	* math/test-logdouble.h: Likewise.

	* setjmp/setjmp.h: Change references of ANSI C to ISO C.
	* setjmp/tst-setjmp.c: Correct and extend test suite.
	* sysdeps/i386/__longjmp.S: Update copyright.
	* sysdeps/i386/bsd-_setjmp.S: Correct fatal bug in jump to
	`__sigsetjmp' in PIC code.
	* sysdeps/i386/bsd-setjmp.S: Likewise.

	* sysdeps/libm-i387/e_pow.S: Correct recognition of mantissa
	overflow.
	* sysdeps/libm-i387/e_powf.S: Likewise.
	* sysdeps/libm-i387/s_expm1.S: Handle x == +-0 as a special
	case since expm1(-0) == -0.
	* sysdeps/libm-i387/s_expm1f.S: Likewise.
	* sysdeps/libm-i387/s_expm1l.S: Likewise.
	* sysdeps/libm-ieee754/s_modf.c: Optimize code by avoiding unneeded
	access to FP number.
	* sysdeps/libm-ieee754/s_modff.c: Likewise.
	* sysdeps/libm-ieee754/s_modfl.c: Correct former completely bogus
	code.  It never worked correctly.
	* sysdeps/libm-ieee754/s_tanh.c: Handle x == +-0 as a special
	case since tanh(-0) == -0.
	* sysdeps/libm-ieee754/s_tanhf.c: Likewise.

1997-03-19 21:13  Ulrich Drepper  <drepper@cygnus.com>

	* stdlib/strtod.c (STRTOL): Use wchar_t as type for `decimal' and
	`thousands' to support systems with sizeof(wchar_t) !=
	sizeof(wint_t).  Blargh.

	* sysdeps/unix/sysv/linux/socketbits.h: Remove definition of
	SOL_IP, SOL_TCP, SOL_UDP, and SOL_IPX as they are defined in
	appropriate headers.

	* sysdeps/unix/sysv/linux/writev.c: Don't use MAX_IOVEC.  Test for
	UIO_FASTIOV and set to 8 if not available.
	* sysdeps/unix/sysv/linux/readv.c: Likewise.
	Patch by HJ Lu.

	* sysdeps/unix/sysv/linux/xstat.c: Include <kernel_stat.h>, not
	"kernel_stat.h".
	* sysdeps/unix/sysv/linux/lxstat.c: Likewise.
	* sysdeps/unix/sysv/linux/fxstat.c: Likewise.
	Reported by fabsoft@fabsoft2.zarm.uni-bremen.de.
1997-03-20 02:20:57 +00:00

96 lines
2.4 KiB
C

/* s_tanhl.c -- long double version of s_tanh.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, drepper@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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/* tanhl(x)
* Return the Hyperbolic Tangent of x
*
* Method :
* x -x
* e - e
* 0. tanhl(x) is defined to be -----------
* x -x
* e + e
* 1. reduce x to non-negative by tanhl(-x) = -tanhl(x).
* 2. 0 <= x <= 2**-55 : tanhl(x) := x*(one+x)
* -t
* 2**-55 < x <= 1 : tanhl(x) := -----; t = expm1l(-2x)
* t + 2
* 2
* 1 <= x <= 23.0 : tanhl(x) := 1- ----- ; t=expm1l(2x)
* t + 2
* 23.0 < x <= INF : tanhl(x) := 1.
*
* Special cases:
* tanhl(NaN) is NaN;
* only tanhl(0)=0 is exact for finite argument.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double one=1.0, two=2.0, tiny = 1.0e-4900L;
#else
static long double one=1.0, two=2.0, tiny = 1.0e-4900L;
#endif
#ifdef __STDC__
long double __tanhl(long double x)
#else
long double __tanhl(x)
long double x;
#endif
{
long double t,z;
int32_t se;
u_int32_t j0,j1,ix;
/* High word of |x|. */
GET_LDOUBLE_WORDS(se,j0,j1,x);
ix = se&0x7fff;
/* x is INF or NaN */
if(ix==0x7fff) {
/* for NaN it's not important which branch: tanhl(NaN) = NaN */
if (se&0x8000) return one/x-one; /* tanhl(-inf)= -1; */
else return one/x+one; /* tanhl(+inf)=+1 */
}
/* |x| < 23 */
if (ix < 0x4003 || (ix == 0x4003 && j0 < 0xb8000000u)) {/* |x|<23 */
if ((ix|j0|j1) == 0)
return x; /* x == +- 0 */
if (ix<0x3fc8) /* |x|<2**-55 */
return x*(one+x); /* tanh(small) = small */
if (ix>=0x3fff) { /* |x|>=1 */
t = __expm1l(two*fabsl(x));
z = one - two/(t+two);
} else {
t = __expm1l(-two*fabsl(x));
z= -t/(t+two);
}
/* |x| > 23, return +-1 */
} else {
z = one - tiny; /* raised inexact flag */
}
return (se>0x7fff)? -z: z;
}
weak_alias (__tanhl, tanhl)