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c57abfa735
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.
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/* @(#)s_tanh.c 5.1 93/09/24 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: s_tanh.c,v 1.7 1995/05/10 20:48:22 jtc Exp $";
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#endif
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/* Tanh(x)
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* Return the Hyperbolic Tangent of x
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*
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* Method :
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* x -x
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* e - e
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* 0. tanh(x) is defined to be -----------
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* x -x
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* e + e
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* 1. reduce x to non-negative by tanh(-x) = -tanh(x).
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* 2. 0 <= x <= 2**-55 : tanh(x) := x*(one+x)
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* -t
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* 2**-55 < x <= 1 : tanh(x) := -----; t = expm1(-2x)
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* t + 2
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* 2
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* 1 <= x <= 22.0 : tanh(x) := 1- ----- ; t=expm1(2x)
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* t + 2
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* 22.0 < x <= INF : tanh(x) := 1.
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*
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* Special cases:
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* tanh(NaN) is NaN;
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* only tanh(0)=0 is exact for finite argument.
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*/
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const double one=1.0, two=2.0, tiny = 1.0e-300;
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#else
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static double one=1.0, two=2.0, tiny = 1.0e-300;
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#endif
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#ifdef __STDC__
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double __tanh(double x)
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#else
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double __tanh(x)
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double x;
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#endif
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{
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double t,z;
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int32_t jx,ix,lx;
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/* High word of |x|. */
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EXTRACT_WORDS(jx,lx,x);
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ix = jx&0x7fffffff;
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/* x is INF or NaN */
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if(ix>=0x7ff00000) {
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if (jx>=0) return one/x+one; /* tanh(+-inf)=+-1 */
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else return one/x-one; /* tanh(NaN) = NaN */
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}
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/* |x| < 22 */
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if (ix < 0x40360000) { /* |x|<22 */
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if ((ix | lx) == 0)
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return x; /* x == +-0 */
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if (ix<0x3c800000) /* |x|<2**-55 */
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return x*(one+x); /* tanh(small) = small */
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if (ix>=0x3ff00000) { /* |x|>=1 */
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t = __expm1(two*fabs(x));
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z = one - two/(t+two);
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} else {
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t = __expm1(-two*fabs(x));
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z= -t/(t+two);
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}
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/* |x| > 22, return +-1 */
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} else {
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z = one - tiny; /* raised inexact flag */
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}
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return (jx>=0)? z: -z;
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}
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weak_alias (__tanh, tanh)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__tanh, __tanhl)
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weak_alias (__tanh, tanhl)
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#endif
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