/* $NetBSD: fpu_hyperb.c,v 1.17 2016/12/05 15:31:01 isaki Exp $ */

/* $NetBSD: fpu_hyperb.c,v 1.17 2016/12/05 15:31:01 isaki Exp $ */

/*
* Copyright (c) 1995 Ken Nakata
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)fpu_hyperb.c 10/24/95
*/

/*
* Copyright (c) 2011 Tetsuya Isaki. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fpu_hyperb.c,v 1.17 2016/12/05 15:31:01 isaki Exp $");

#include <machine/ieee.h>

#include "fpu_emulate.h"

/*
* fpu_hyperb.c: defines the following functions
*
* fpu_atanh(), fpu_cosh(), fpu_sinh(), and fpu_tanh()
*/

/*
* 1 1 + x
* atanh(x) = ---*log(-------)
* 2 1 - x
*/
struct fpn *
fpu_atanh(struct fpemu *fe)
{
struct fpn x;
struct fpn t;
struct fpn *r;

if (ISNAN(&fe->fe_f2))
return &fe->fe_f2;
if (ISINF(&fe->fe_f2))
return fpu_newnan(fe);

/* if x is +0/-0, return +0/-0 */
if (ISZERO(&fe->fe_f2))
return &fe->fe_f2;

/*
* -INF if x == -1
* +INF if x == 1
*/
r = &fe->fe_f2;
if (r->fp_exp == 0 && r->fp_mant[0] == FP_1 &&
r->fp_mant[1] == 0 && r->fp_mant[2] == 0) {
r->fp_class = FPC_INF;
return r;
}

/* NAN if |x| > 1 */
if (fe->fe_f2.fp_exp >= 0)
return fpu_newnan(fe);

CPYFPN(&x, &fe->fe_f2);

/* t := 1 - x */
fpu_const(&fe->fe_f1, FPU_CONST_1);
fe->fe_f2.fp_sign = !fe->fe_f2.fp_sign;
r = fpu_add(fe);
CPYFPN(&t, r);

/* r := 1 + x */
fpu_const(&fe->fe_f1, FPU_CONST_1);
CPYFPN(&fe->fe_f2, &x);
r = fpu_add(fe);

/* (1-x)/(1+x) */
CPYFPN(&fe->fe_f1, r);
CPYFPN(&fe->fe_f2, &t);
r = fpu_div(fe);

/* log((1-x)/(1+x)) */
CPYFPN(&fe->fe_f2, r);
r = fpu_logn(fe);

/* r /= 2 */
r->fp_exp--;

return r;
}

/*
* exp(x) + exp(-x)
* cosh(x) = ------------------
* 2
*/
struct fpn *
fpu_cosh(struct fpemu *fe)
{
struct fpn x, *fp;

if (ISNAN(&fe->fe_f2))
return &fe->fe_f2;

if (ISINF(&fe->fe_f2)) {
fe->fe_f2.fp_sign = 0;
return &fe->fe_f2;
}

/* if x is +0/-0, return 1 */ /* XXX is this necessary? */
if (ISZERO(&fe->fe_f2)) {
fpu_const(&fe->fe_f2, FPU_CONST_1);
return &fe->fe_f2;
}

fp = fpu_etox(fe);
CPYFPN(&x, fp);

fpu_const(&fe->fe_f1, FPU_CONST_1);
CPYFPN(&fe->fe_f2, fp);
fp = fpu_div(fe);

CPYFPN(&fe->fe_f1, fp);
CPYFPN(&fe->fe_f2, &x);
fp = fpu_add(fe);

fp->fp_exp--;

return fp;
}

/*
* exp(x) - exp(-x)
* sinh(x) = ------------------
* 2
*/
struct fpn *
fpu_sinh(struct fpemu *fe)
{
struct fpn x, *fp;

if (ISNAN(&fe->fe_f2))
return &fe->fe_f2;
if (ISINF(&fe->fe_f2))
return &fe->fe_f2;

/* if x is +0/-0, return +0/-0 */
if (ISZERO(&fe->fe_f2))
return &fe->fe_f2;

fp = fpu_etox(fe);
CPYFPN(&x, fp);

fpu_const(&fe->fe_f1, FPU_CONST_1);
CPYFPN(&fe->fe_f2, fp);
fp = fpu_div(fe);

fp->fp_sign = 1;
CPYFPN(&fe->fe_f1, fp);
CPYFPN(&fe->fe_f2, &x);
fp = fpu_add(fe);

fp->fp_exp--;

return fp;
}

/*
* sinh(x)
* tanh(x) = ---------
* cosh(x)
*/
struct fpn *
fpu_tanh(struct fpemu *fe)
{
struct fpn x;
struct fpn s;
struct fpn *r;
int sign;

if (ISNAN(&fe->fe_f2))
return &fe->fe_f2;

/* if x is +0/-0, return +0/-0 */
if (ISZERO(&fe->fe_f2))
return &fe->fe_f2;

if (ISINF(&fe->fe_f2)) {
sign = fe->fe_f2.fp_sign;
fpu_const(&fe->fe_f2, FPU_CONST_1);
fe->fe_f2.fp_sign = sign;
return &fe->fe_f2;
}

CPYFPN(&x, &fe->fe_f2);

/* sinh(x) */
CPYFPN(&fe->fe_f2, &x);
r = fpu_sinh(fe);
CPYFPN(&s, r);

/* cosh(x) */
CPYFPN(&fe->fe_f2, &x);
r = fpu_cosh(fe);
CPYFPN(&fe->fe_f2, r);

CPYFPN(&fe->fe_f1, &s);
r = fpu_div(fe);

return r;
}