fpu_hyperb.c revision 1.9
1 /* $NetBSD: fpu_hyperb.c,v 1.9 2013/04/19 13:31:11 isaki Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Ken Nakata 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the author nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)fpu_hyperb.c 10/24/95 32 */ 33 34 /* 35 * Copyright (c) 2011 Tetsuya Isaki. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 46 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 47 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 48 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 49 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 50 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 51 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 52 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 53 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 54 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 56 * SUCH DAMAGE. 57 */ 58 59 #include <sys/cdefs.h> 60 __KERNEL_RCSID(0, "$NetBSD: fpu_hyperb.c,v 1.9 2013/04/19 13:31:11 isaki Exp $"); 61 62 #include "fpu_emulate.h" 63 64 /* 65 * fpu_hyperb.c: defines the following functions 66 * 67 * fpu_atanh(), fpu_cosh(), fpu_sinh(), and fpu_tanh() 68 */ 69 70 struct fpn * 71 fpu_atanh(struct fpemu *fe) 72 { 73 /* stub */ 74 return &fe->fe_f2; 75 } 76 77 /* 78 * taylor expansion used by sinh(), cosh(). 79 */ 80 static struct fpn * 81 __fpu_sinhcosh_taylor(struct fpemu *fe, struct fpn *s0, uint32_t f) 82 { 83 struct fpn res; 84 struct fpn x2; 85 struct fpn *s1; 86 struct fpn *r; 87 int sign; 88 uint32_t k; 89 90 /* x2 := x * x */ 91 CPYFPN(&fe->fe_f1, &fe->fe_f2); 92 r = fpu_mul(fe); 93 CPYFPN(&x2, r); 94 95 /* res := s0 */ 96 CPYFPN(&res, s0); 97 98 sign = 1; /* sign := (-1)^n */ 99 100 for (;;) { 101 /* (f1 :=) s0 * x^2 */ 102 CPYFPN(&fe->fe_f1, s0); 103 CPYFPN(&fe->fe_f2, &x2); 104 r = fpu_mul(fe); 105 CPYFPN(&fe->fe_f1, r); 106 107 /* 108 * for sin(), s1 := s0 * x^2 / (2n+1)2n 109 * for cos(), s1 := s0 * x^2 / 2n(2n-1) 110 */ 111 k = f * (f + 1); 112 fpu_explode(fe, &fe->fe_f2, FTYPE_LNG, &k); 113 s1 = fpu_div(fe); 114 115 /* break if s1 is enough small */ 116 if (ISZERO(s1)) 117 break; 118 if (res.fp_exp - s1->fp_exp >= FP_NMANT) 119 break; 120 121 /* s0 := s1 for next loop */ 122 CPYFPN(s0, s1); 123 124 /* res += s1 */ 125 CPYFPN(&fe->fe_f2, s1); 126 CPYFPN(&fe->fe_f1, &res); 127 r = fpu_add(fe); 128 CPYFPN(&res, r); 129 130 f += 2; 131 sign ^= 1; 132 } 133 134 CPYFPN(&fe->fe_f2, &res); 135 return &fe->fe_f2; 136 } 137 138 struct fpn * 139 fpu_cosh(struct fpemu *fe) 140 { 141 struct fpn s0; 142 struct fpn *r; 143 144 if (ISNAN(&fe->fe_f2)) 145 return &fe->fe_f2; 146 147 if (ISINF(&fe->fe_f2)) { 148 fe->fe_f2.fp_sign = 0; 149 return &fe->fe_f2; 150 } 151 152 fpu_const(&s0, FPU_CONST_1); 153 r = __fpu_sinhcosh_taylor(fe, &s0, 1); 154 CPYFPN(&fe->fe_f2, r); 155 156 return &fe->fe_f2; 157 } 158 159 struct fpn * 160 fpu_sinh(struct fpemu *fe) 161 { 162 struct fpn s0; 163 struct fpn *r; 164 165 if (ISNAN(&fe->fe_f2)) 166 return &fe->fe_f2; 167 if (ISINF(&fe->fe_f2)) 168 return &fe->fe_f2; 169 170 CPYFPN(&s0, &fe->fe_f2); 171 r = __fpu_sinhcosh_taylor(fe, &s0, 2); 172 CPYFPN(&fe->fe_f2, r); 173 174 return &fe->fe_f2; 175 } 176 177 struct fpn * 178 fpu_tanh(struct fpemu *fe) 179 { 180 struct fpn x; 181 struct fpn s; 182 struct fpn *r; 183 int sign; 184 185 if (ISNAN(&fe->fe_f2)) 186 return &fe->fe_f2; 187 188 if (ISINF(&fe->fe_f2)) { 189 sign = fe->fe_f2.fp_sign; 190 fpu_const(&fe->fe_f2, FPU_CONST_1); 191 fe->fe_f2.fp_sign = sign; 192 return &fe->fe_f2; 193 } 194 195 CPYFPN(&x, &fe->fe_f2); 196 197 /* sinh(x) */ 198 CPYFPN(&fe->fe_f2, &x); 199 r = fpu_sinh(fe); 200 CPYFPN(&s, r); 201 202 /* cosh(x) */ 203 CPYFPN(&fe->fe_f2, &x); 204 r = fpu_cosh(fe); 205 CPYFPN(&fe->fe_f2, r); 206 207 CPYFPN(&fe->fe_f1, &s); 208 r = fpu_div(fe); 209 210 CPYFPN(&fe->fe_f2, r); 211 212 return &fe->fe_f2; 213 } 214
Indexes created Mon Sep 29 21:09:56 GMT 2025