Markos Chandras | 4e9561b | 2015-08-13 09:56:35 +0200 | [diff] [blame] | 1 | /* |
| 2 | * IEEE754 floating point arithmetic |
| 3 | * single precision: MIN{,A}.f |
| 4 | * MIN : Scalar Floating-Point Minimum |
| 5 | * MINA: Scalar Floating-Point argument with Minimum Absolute Value |
| 6 | * |
| 7 | * MIN.S : FPR[fd] = minNum(FPR[fs],FPR[ft]) |
| 8 | * MINA.S: FPR[fd] = maxNumMag(FPR[fs],FPR[ft]) |
| 9 | * |
| 10 | * MIPS floating point support |
| 11 | * Copyright (C) 2015 Imagination Technologies, Ltd. |
| 12 | * Author: Markos Chandras <markos.chandras@imgtec.com> |
| 13 | * |
| 14 | * This program is free software; you can distribute it and/or modify it |
| 15 | * under the terms of the GNU General Public License as published by the |
| 16 | * Free Software Foundation; version 2 of the License. |
| 17 | */ |
| 18 | |
| 19 | #include "ieee754sp.h" |
| 20 | |
| 21 | union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y) |
| 22 | { |
| 23 | COMPXSP; |
| 24 | COMPYSP; |
| 25 | |
| 26 | EXPLODEXSP; |
| 27 | EXPLODEYSP; |
| 28 | |
| 29 | FLUSHXSP; |
| 30 | FLUSHYSP; |
| 31 | |
| 32 | ieee754_clearcx(); |
| 33 | |
| 34 | switch (CLPAIR(xc, yc)) { |
| 35 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): |
| 36 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): |
| 37 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): |
| 38 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): |
| 39 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): |
| 40 | return ieee754sp_nanxcpt(y); |
| 41 | |
| 42 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): |
| 43 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): |
| 44 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): |
| 45 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): |
| 46 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): |
| 47 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): |
| 48 | return ieee754sp_nanxcpt(x); |
| 49 | |
Aleksandar Markovic | b234149 | 2017-07-27 18:08:48 +0200 | [diff] [blame^] | 50 | /* |
| 51 | * Quiet NaN handling |
| 52 | */ |
| 53 | |
| 54 | /* |
| 55 | * The case of both inputs quiet NaNs |
| 56 | */ |
| 57 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN): |
| 58 | return x; |
| 59 | |
| 60 | /* |
| 61 | * The cases of exactly one input quiet NaN (numbers |
| 62 | * are here preferred as returned values to NaNs) |
| 63 | */ |
Markos Chandras | 4e9561b | 2015-08-13 09:56:35 +0200 | [diff] [blame] | 64 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): |
| 65 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): |
| 66 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN): |
| 67 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN): |
| 68 | return x; |
| 69 | |
Markos Chandras | 4e9561b | 2015-08-13 09:56:35 +0200 | [diff] [blame] | 70 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO): |
| 71 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM): |
| 72 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM): |
| 73 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF): |
| 74 | return y; |
| 75 | |
| 76 | /* |
| 77 | * Infinity and zero handling |
| 78 | */ |
| 79 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): |
| 80 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM): |
| 81 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): |
| 82 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): |
| 83 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): |
| 84 | return xs ? x : y; |
| 85 | |
| 86 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): |
| 87 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF): |
| 88 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): |
| 89 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): |
| 90 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): |
| 91 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): |
| 92 | return ys ? y : x; |
| 93 | |
| 94 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): |
| 95 | if (xs == ys) |
| 96 | return x; |
| 97 | return ieee754sp_zero(1); |
| 98 | |
| 99 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): |
| 100 | SPDNORMX; |
| 101 | |
| 102 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): |
| 103 | SPDNORMY; |
| 104 | break; |
| 105 | |
| 106 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM): |
| 107 | SPDNORMX; |
| 108 | } |
| 109 | |
| 110 | /* Finally get to do some computation */ |
| 111 | |
| 112 | assert(xm & SP_HIDDEN_BIT); |
| 113 | assert(ym & SP_HIDDEN_BIT); |
| 114 | |
| 115 | /* Compare signs */ |
| 116 | if (xs > ys) |
| 117 | return x; |
| 118 | else if (xs < ys) |
| 119 | return y; |
| 120 | |
| 121 | /* Compare exponent */ |
| 122 | if (xe > ye) |
| 123 | return y; |
| 124 | else if (xe < ye) |
| 125 | return x; |
| 126 | |
| 127 | /* Compare mantissa */ |
| 128 | if (xm <= ym) |
| 129 | return x; |
| 130 | return y; |
| 131 | } |
| 132 | |
| 133 | union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y) |
| 134 | { |
| 135 | COMPXSP; |
| 136 | COMPYSP; |
| 137 | |
| 138 | EXPLODEXSP; |
| 139 | EXPLODEYSP; |
| 140 | |
| 141 | FLUSHXSP; |
| 142 | FLUSHYSP; |
| 143 | |
| 144 | ieee754_clearcx(); |
| 145 | |
| 146 | switch (CLPAIR(xc, yc)) { |
| 147 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN): |
| 148 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN): |
| 149 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN): |
| 150 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN): |
| 151 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN): |
| 152 | return ieee754sp_nanxcpt(y); |
| 153 | |
| 154 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN): |
| 155 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN): |
| 156 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO): |
| 157 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM): |
| 158 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM): |
| 159 | case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF): |
| 160 | return ieee754sp_nanxcpt(x); |
| 161 | |
Aleksandar Markovic | b234149 | 2017-07-27 18:08:48 +0200 | [diff] [blame^] | 162 | /* |
| 163 | * Quiet NaN handling |
| 164 | */ |
| 165 | |
| 166 | /* |
| 167 | * The case of both inputs quiet NaNs |
| 168 | */ |
| 169 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN): |
| 170 | return x; |
| 171 | |
| 172 | /* |
| 173 | * The cases of exactly one input quiet NaN (numbers |
| 174 | * are here preferred as returned values to NaNs) |
| 175 | */ |
Markos Chandras | 4e9561b | 2015-08-13 09:56:35 +0200 | [diff] [blame] | 176 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN): |
| 177 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN): |
| 178 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN): |
| 179 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN): |
| 180 | return x; |
| 181 | |
Markos Chandras | 4e9561b | 2015-08-13 09:56:35 +0200 | [diff] [blame] | 182 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO): |
| 183 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM): |
| 184 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM): |
| 185 | case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF): |
| 186 | return y; |
| 187 | |
| 188 | /* |
| 189 | * Infinity and zero handling |
| 190 | */ |
| 191 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO): |
| 192 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM): |
| 193 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM): |
| 194 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO): |
| 195 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO): |
| 196 | return x; |
| 197 | |
| 198 | case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF): |
| 199 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF): |
| 200 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF): |
| 201 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF): |
| 202 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM): |
| 203 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM): |
| 204 | return y; |
| 205 | |
| 206 | case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO): |
| 207 | if (xs == ys) |
| 208 | return x; |
| 209 | return ieee754sp_zero(1); |
| 210 | |
| 211 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM): |
| 212 | SPDNORMX; |
| 213 | |
| 214 | case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM): |
| 215 | SPDNORMY; |
| 216 | break; |
| 217 | |
| 218 | case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM): |
| 219 | SPDNORMX; |
| 220 | } |
| 221 | |
| 222 | /* Finally get to do some computation */ |
| 223 | |
| 224 | assert(xm & SP_HIDDEN_BIT); |
| 225 | assert(ym & SP_HIDDEN_BIT); |
| 226 | |
| 227 | /* Compare exponent */ |
| 228 | if (xe > ye) |
| 229 | return y; |
| 230 | else if (xe < ye) |
| 231 | return x; |
| 232 | |
| 233 | /* Compare mantissa */ |
| 234 | if (xm <= ym) |
| 235 | return x; |
| 236 | return y; |
| 237 | } |