newlib/winsup/cygwin/math/tanhl.c

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/**
* This file has no copyright assigned and is placed in the Public Domain.
* This file is part of the mingw-w64 runtime package.
* No warranty is given; refer to the file DISCLAIMER.PD within this package.
*/
#include "cephes_mconf.h"
#ifndef _SET_ERRNO
#define _SET_ERRNO(x)
#endif
#ifdef UNK
static uLD P[] = {
{ { -6.8473739392677100872869E-5L } },
{ { -9.5658283111794641589011E-1L } },
{ { -8.4053568599672284488465E1L } },
{ { -1.3080425704712825945553E3L } }
};
static uLD Q[] = {
{ { 9.6259501838840336946872E1L } },
{ { 1.8218117903645559060232E3L } },
{ { 3.9241277114138477845780E3L } }
};
#endif
#ifdef IBMPC
static uLD P[] = {
{ { 0xd2a4,0x1b0c,0x8f15,0x8f99,0xbff1, 0, 0, 0 } },
{ { 0x5959,0x9111,0x9cc7,0xf4e2,0xbffe, 0, 0, 0 } },
{ { 0xb576,0xef5e,0x6d57,0xa81b,0xc005, 0, 0, 0 } },
{ { 0xe3be,0xbfbd,0x5cbc,0xa381,0xc009, 0, 0, 0 } }
};
static uLD Q[] = {
{ { 0x687f,0xce24,0xdd6c,0xc084,0x4005, 0, 0, 0 } },
{ { 0x3793,0xc95f,0xfa2f,0xe3b9,0x4009, 0, 0, 0 } },
{ { 0xd5a2,0x1f9c,0x0b1b,0xf542,0x400a, 0, 0, 0 } }
};
#endif
#ifdef MIEEE
static uLD P[] = {
{ { 0xbff10000,0x8f998f15,0x1b0cd2a4, 0 } },
{ { 0xbffe0000,0xf4e29cc7,0x91115959, 0 } },
{ { 0xc0050000,0xa81b6d57,0xef5eb576, 0 } },
{ { 0xc0090000,0xa3815cbc,0xbfbde3be, 0 } }
};
static uLD Q[] = {
{ { 0x40050000,0xc084dd6c,0xce24687f, 0 } },
{ { 0x40090000,0xe3b9fa2f,0xc95f3793, 0 } },
{ { 0x400a0000,0xf5420b1b,0x1f9cd5a2, 0 } }
};
#endif
long double tanhl(long double x)
{
long double s, z;
#ifdef MINUSZERO
if (x == 0.0L)
return (x);
#endif
if (isnanl(x))
{
_SET_ERRNO (EDOM);
return x;
}
z = fabsl(x);
if (z > 0.5L * MAXLOGL)
{
_SET_ERRNO (ERANGE);
if (x > 0)
return (1.0L);
else
return (-1.0L);
}
if (z >= 0.625L)
{
s = expl(2.0*z);
z = 1.0L - 2.0/(s + 1.0L);
if (x < 0)
z = -z;
}
else
{
s = x * x;
z = polevll( s, P, 3 )/p1evll(s, Q, 3);
z = x * s * z;
z = x + z;
}
return (z);
}