Rev 660 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 647 | cejka | 1 | /* |
| 2 | * Copyright (C) 2005 Josef Cejka |
||
| 3 | * All rights reserved. |
||
| 4 | * |
||
| 5 | * Redistribution and use in source and binary forms, with or without |
||
| 6 | * modification, are permitted provided that the following conditions |
||
| 7 | * are met: |
||
| 8 | * |
||
| 9 | * - Redistributions of source code must retain the above copyright |
||
| 10 | * notice, this list of conditions and the following disclaimer. |
||
| 11 | * - Redistributions in binary form must reproduce the above copyright |
||
| 12 | * notice, this list of conditions and the following disclaimer in the |
||
| 13 | * documentation and/or other materials provided with the distribution. |
||
| 14 | * - The name of the author may not be used to endorse or promote products |
||
| 15 | * derived from this software without specific prior written permission. |
||
| 16 | * |
||
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
||
| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
||
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
||
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
||
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
||
| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
||
| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
||
| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
||
| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
||
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||
| 27 | */ |
||
| 28 | |||
| 29 | #include<sftypes.h> |
||
| 30 | #include<arithmetic.h> |
||
| 660 | cejka | 31 | #include<comparison.h> |
| 647 | cejka | 32 | |
| 33 | /** Add two Float32 numbers with same signs |
||
| 34 | */ |
||
| 35 | float32 addFloat32(float32 a, float32 b) |
||
| 36 | { |
||
| 37 | int expdiff; |
||
| 38 | __u32 exp1,exp2,mant1,mant2; |
||
| 39 | |||
| 40 | expdiff=a.parts.exp - b.parts.exp; |
||
| 41 | if (expdiff<0) { |
||
| 42 | if (isFloat32NaN(b)) { |
||
| 43 | //TODO: fix SigNaN |
||
| 44 | if (isFloat32SigNaN(b)) { |
||
| 45 | }; |
||
| 46 | return b; |
||
| 47 | }; |
||
| 48 | |||
| 49 | if (b.parts.exp==0xFF) { |
||
| 50 | return b; |
||
| 51 | } |
||
| 52 | |||
| 53 | mant1=b.parts.mantisa; |
||
| 54 | exp1=b.parts.exp; |
||
| 55 | mant2=a.parts.mantisa; |
||
| 56 | exp2=a.parts.exp; |
||
| 57 | expdiff*=-1; |
||
| 58 | } else { |
||
| 59 | if (isFloat32NaN(a)) { |
||
| 60 | //TODO: fix SigNaN |
||
| 61 | if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) { |
||
| 62 | }; |
||
| 63 | return a; |
||
| 64 | }; |
||
| 65 | |||
| 66 | if (a.parts.exp==0xFF) { |
||
| 67 | return a; |
||
| 68 | } |
||
| 69 | |||
| 70 | mant1=a.parts.mantisa; |
||
| 71 | exp1=a.parts.exp; |
||
| 72 | mant2=b.parts.mantisa; |
||
| 73 | exp2=b.parts.exp; |
||
| 74 | }; |
||
| 75 | |||
| 76 | if (exp1==0) { |
||
| 77 | //both are denormalized |
||
| 78 | mant1+=mant2; |
||
| 79 | if (mant1&0xF00000) { |
||
| 80 | a.parts.exp=1; |
||
| 81 | }; |
||
| 82 | a.parts.mantisa=mant1; |
||
| 83 | return a; |
||
| 84 | }; |
||
| 85 | |||
| 86 | // create some space for rounding |
||
| 87 | mant1<<=6; |
||
| 88 | mant2<<=6; |
||
| 89 | |||
| 90 | mant1|=0x20000000; //add hidden bit |
||
| 91 | |||
| 92 | |||
| 93 | if (exp2==0) { |
||
| 94 | --expdiff; |
||
| 95 | } else { |
||
| 96 | mant2|=0x20000000; //hidden bit |
||
| 97 | }; |
||
| 98 | |||
| 99 | if (expdiff>24) { |
||
| 100 | goto done; |
||
| 101 | }; |
||
| 102 | |||
| 103 | mant2>>=expdiff; |
||
| 104 | mant1+=mant2; |
||
| 105 | done: |
||
| 106 | if (mant1&0x40000000) { |
||
| 107 | ++exp1; |
||
| 108 | mant1>>=1; |
||
| 109 | }; |
||
| 110 | |||
| 111 | //rounding - if first bit after mantisa is set then round up |
||
| 112 | mant1+=0x20; |
||
| 113 | |||
| 661 | cejka | 114 | if (mant1&0x40000000) { |
| 115 | ++exp1; |
||
| 116 | mant1>>=1; |
||
| 117 | }; |
||
| 118 | |||
| 647 | cejka | 119 | a.parts.exp=exp1; |
| 661 | cejka | 120 | a.parts.mantisa = ((mant1&(~0x20000000))>>6); /*Clear hidden bit and shift */ |
| 647 | cejka | 121 | return a; |
| 122 | }; |
||
| 123 | |||
| 661 | cejka | 124 | /** Subtract two float32 numbers with same signs |
| 647 | cejka | 125 | */ |
| 126 | float32 subFloat32(float32 a, float32 b) |
||
| 127 | { |
||
| 661 | cejka | 128 | int expdiff; |
| 129 | __u32 exp1,exp2,mant1,mant2; |
||
| 130 | float32 result; |
||
| 131 | |||
| 132 | result.f = 0; |
||
| 647 | cejka | 133 | |
| 661 | cejka | 134 | expdiff=a.parts.exp - b.parts.exp; |
| 135 | if ((expdiff<0)||((expdiff==0)&&(a.parts.mantisa<b.parts.mantisa))) { |
||
| 136 | if (isFloat32NaN(b)) { |
||
| 137 | //TODO: fix SigNaN |
||
| 138 | if (isFloat32SigNaN(b)) { |
||
| 139 | }; |
||
| 140 | return b; |
||
| 141 | }; |
||
| 142 | |||
| 143 | if (b.parts.exp==0xFF) { |
||
| 144 | b.parts.sign=!b.parts.sign; /* num -(+-inf) = -+inf */ |
||
| 145 | return b; |
||
| 146 | } |
||
| 147 | |||
| 148 | result.parts.sign = !a.parts.sign; |
||
| 149 | |||
| 150 | mant1=b.parts.mantisa; |
||
| 151 | exp1=b.parts.exp; |
||
| 152 | mant2=a.parts.mantisa; |
||
| 153 | exp2=a.parts.exp; |
||
| 154 | expdiff*=-1; |
||
| 155 | } else { |
||
| 156 | if (isFloat32NaN(a)) { |
||
| 157 | //TODO: fix SigNaN |
||
| 158 | if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) { |
||
| 159 | }; |
||
| 160 | return a; |
||
| 161 | }; |
||
| 162 | |||
| 163 | if (a.parts.exp==0xFF) { |
||
| 164 | if (b.parts.exp==0xFF) { |
||
| 165 | /* inf - inf => nan */ |
||
| 166 | //TODO: fix exception |
||
| 167 | result.binary = FLOAT32_NAN; |
||
| 168 | return result; |
||
| 169 | }; |
||
| 170 | return a; |
||
| 171 | } |
||
| 172 | |||
| 173 | result.parts.sign = a.parts.sign; |
||
| 174 | |||
| 175 | mant1=a.parts.mantisa; |
||
| 176 | exp1=a.parts.exp; |
||
| 177 | mant2=b.parts.mantisa; |
||
| 178 | exp2=b.parts.exp; |
||
| 179 | |||
| 180 | |||
| 181 | |||
| 182 | }; |
||
| 647 | cejka | 183 | |
| 661 | cejka | 184 | if (exp1==0) { |
| 185 | //both are denormalized |
||
| 186 | result.parts.mantisa=mant1-mant2; |
||
| 187 | if (result.parts.mantisa>mant1) { |
||
| 188 | //TODO: underflow exception |
||
| 189 | return result; |
||
| 190 | }; |
||
| 191 | result.parts.exp=0; |
||
| 192 | return result; |
||
| 193 | }; |
||
| 194 | |||
| 195 | // create some space for rounding |
||
| 196 | mant1<<=6; |
||
| 197 | mant2<<=6; |
||
| 198 | |||
| 199 | mant1|=0x20000000; //add hidden bit |
||
| 200 | |||
| 201 | |||
| 202 | if (exp2==0) { |
||
| 203 | --expdiff; |
||
| 204 | } else { |
||
| 205 | mant2|=0x20000000; //hidden bit |
||
| 206 | }; |
||
| 207 | |||
| 208 | if (expdiff>24) { |
||
| 209 | goto done; |
||
| 210 | }; |
||
| 211 | |||
| 212 | mant1 = mant1-(mant2>>expdiff); |
||
| 213 | done: |
||
| 214 | |||
| 215 | //TODO: find first nonzero digit and shift result and detect possibly underflow |
||
| 216 | while ((exp1>0)&&(!(mant1&0x20000000))) { |
||
| 217 | exp1--; |
||
| 218 | mant1 <<= 1; |
||
| 219 | if(mant1 == 0) { |
||
| 220 | /* Realy is it an underflow? ... */ |
||
| 221 | //TODO: fix underflow |
||
| 222 | }; |
||
| 223 | }; |
||
| 224 | |||
| 225 | //rounding - if first bit after mantisa is set then round up |
||
| 226 | mant1 += 0x20; |
||
| 227 | |||
| 228 | if (mant1&0x40000000) { |
||
| 229 | ++exp1; |
||
| 230 | mant1>>=1; |
||
| 231 | }; |
||
| 232 | |||
| 233 | result.parts.mantisa = ((mant1&(~0x20000000))>>6); /*Clear hidden bit and shift */ |
||
| 234 | result.parts.exp = exp1; |
||
| 235 | |||
| 236 | return result; |
||
| 647 | cejka | 237 | }; |
| 238 |