/* $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; }
