[b5440cf] | 1 | /*
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| 2 | * Copyright (C) 2005 Josef Cejka
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | #include<sftypes.h>
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| 30 | #include<arithmetic.h>
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[cf4a823] | 31 | #include<comparison.h>
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[b5440cf] | 32 |
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| 33 | /** Add two Float32 numbers with same signs
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| 34 | */
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| 35 | float32 addFloat32(float32 a, float32 b)
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| 36 | {
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| 37 | int expdiff;
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| 38 | __u32 exp1,exp2,mant1,mant2;
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| 39 |
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| 40 | expdiff=a.parts.exp - b.parts.exp;
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| 41 | if (expdiff<0) {
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| 42 | if (isFloat32NaN(b)) {
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| 43 | //TODO: fix SigNaN
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| 44 | if (isFloat32SigNaN(b)) {
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| 45 | };
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[3af72dc] | 46 |
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[b5440cf] | 47 | return b;
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| 48 | };
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| 49 |
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| 50 | if (b.parts.exp==0xFF) {
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| 51 | return b;
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| 52 | }
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| 53 |
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| 54 | mant1=b.parts.mantisa;
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| 55 | exp1=b.parts.exp;
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| 56 | mant2=a.parts.mantisa;
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| 57 | exp2=a.parts.exp;
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| 58 | expdiff*=-1;
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| 59 | } else {
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| 60 | if (isFloat32NaN(a)) {
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| 61 | //TODO: fix SigNaN
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| 62 | if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) {
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| 63 | };
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| 64 | return a;
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| 65 | };
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| 66 |
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| 67 | if (a.parts.exp==0xFF) {
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| 68 | return a;
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| 69 | }
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| 70 |
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| 71 | mant1=a.parts.mantisa;
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| 72 | exp1=a.parts.exp;
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| 73 | mant2=b.parts.mantisa;
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| 74 | exp2=b.parts.exp;
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| 75 | };
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| 76 |
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| 77 | if (exp1==0) {
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| 78 | //both are denormalized
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| 79 | mant1+=mant2;
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| 80 | if (mant1&0xF00000) {
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| 81 | a.parts.exp=1;
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| 82 | };
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| 83 | a.parts.mantisa=mant1;
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| 84 | return a;
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| 85 | };
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| 86 |
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| 87 | // create some space for rounding
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| 88 | mant1<<=6;
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| 89 | mant2<<=6;
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| 90 |
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| 91 | mant1|=0x20000000; //add hidden bit
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| 92 |
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| 93 |
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| 94 | if (exp2==0) {
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| 95 | --expdiff;
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| 96 | } else {
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| 97 | mant2|=0x20000000; //hidden bit
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| 98 | };
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| 99 |
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| 100 | if (expdiff>24) {
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| 101 | goto done;
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| 102 | };
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| 103 |
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| 104 | mant2>>=expdiff;
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| 105 | mant1+=mant2;
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| 106 | done:
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| 107 | if (mant1&0x40000000) {
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| 108 | ++exp1;
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| 109 | mant1>>=1;
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| 110 | };
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| 111 |
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| 112 | //rounding - if first bit after mantisa is set then round up
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| 113 | mant1+=0x20;
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| 114 |
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[75a23abf] | 115 | if (mant1&0x40000000) {
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| 116 | ++exp1;
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| 117 | mant1>>=1;
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| 118 | };
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| 119 |
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[b5440cf] | 120 | a.parts.exp=exp1;
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[75a23abf] | 121 | a.parts.mantisa = ((mant1&(~0x20000000))>>6); /*Clear hidden bit and shift */
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[b5440cf] | 122 | return a;
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| 123 | };
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| 124 |
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[75a23abf] | 125 | /** Subtract two float32 numbers with same signs
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[b5440cf] | 126 | */
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| 127 | float32 subFloat32(float32 a, float32 b)
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| 128 | {
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[75a23abf] | 129 | int expdiff;
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| 130 | __u32 exp1,exp2,mant1,mant2;
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| 131 | float32 result;
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| 132 |
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| 133 | result.f = 0;
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| 134 |
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| 135 | expdiff=a.parts.exp - b.parts.exp;
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| 136 | if ((expdiff<0)||((expdiff==0)&&(a.parts.mantisa<b.parts.mantisa))) {
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| 137 | if (isFloat32NaN(b)) {
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| 138 | //TODO: fix SigNaN
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| 139 | if (isFloat32SigNaN(b)) {
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| 140 | };
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| 141 | return b;
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| 142 | };
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| 143 |
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| 144 | if (b.parts.exp==0xFF) {
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| 145 | b.parts.sign=!b.parts.sign; /* num -(+-inf) = -+inf */
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| 146 | return b;
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| 147 | }
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| 148 |
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| 149 | result.parts.sign = !a.parts.sign;
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| 150 |
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| 151 | mant1=b.parts.mantisa;
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| 152 | exp1=b.parts.exp;
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| 153 | mant2=a.parts.mantisa;
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| 154 | exp2=a.parts.exp;
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| 155 | expdiff*=-1;
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| 156 | } else {
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| 157 | if (isFloat32NaN(a)) {
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| 158 | //TODO: fix SigNaN
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| 159 | if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) {
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| 160 | };
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| 161 | return a;
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| 162 | };
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| 163 |
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| 164 | if (a.parts.exp==0xFF) {
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| 165 | if (b.parts.exp==0xFF) {
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| 166 | /* inf - inf => nan */
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| 167 | //TODO: fix exception
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| 168 | result.binary = FLOAT32_NAN;
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| 169 | return result;
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| 170 | };
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| 171 | return a;
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| 172 | }
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| 173 |
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| 174 | result.parts.sign = a.parts.sign;
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| 175 |
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| 176 | mant1=a.parts.mantisa;
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| 177 | exp1=a.parts.exp;
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| 178 | mant2=b.parts.mantisa;
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| 179 | exp2=b.parts.exp;
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| 180 |
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| 181 |
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| 182 |
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| 183 | };
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| 184 |
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| 185 | if (exp1==0) {
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| 186 | //both are denormalized
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| 187 | result.parts.mantisa=mant1-mant2;
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| 188 | if (result.parts.mantisa>mant1) {
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| 189 | //TODO: underflow exception
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| 190 | return result;
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| 191 | };
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| 192 | result.parts.exp=0;
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| 193 | return result;
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| 194 | };
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| 195 |
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| 196 | // create some space for rounding
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| 197 | mant1<<=6;
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| 198 | mant2<<=6;
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| 199 |
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| 200 | mant1|=0x20000000; //add hidden bit
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| 201 |
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| 202 |
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| 203 | if (exp2==0) {
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| 204 | --expdiff;
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| 205 | } else {
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| 206 | mant2|=0x20000000; //hidden bit
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| 207 | };
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| 208 |
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| 209 | if (expdiff>24) {
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| 210 | goto done;
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| 211 | };
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| 212 |
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| 213 | mant1 = mant1-(mant2>>expdiff);
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| 214 | done:
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| 215 |
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| 216 | //TODO: find first nonzero digit and shift result and detect possibly underflow
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| 217 | while ((exp1>0)&&(!(mant1&0x20000000))) {
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| 218 | exp1--;
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| 219 | mant1 <<= 1;
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| 220 | if(mant1 == 0) {
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| 221 | /* Realy is it an underflow? ... */
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[3af72dc] | 222 | /* TODO: fix underflow */
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[75a23abf] | 223 | };
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| 224 | };
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| 225 |
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| 226 | //rounding - if first bit after mantisa is set then round up
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| 227 | mant1 += 0x20;
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| 228 |
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| 229 | if (mant1&0x40000000) {
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| 230 | ++exp1;
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| 231 | mant1>>=1;
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| 232 | };
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[b5440cf] | 233 |
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[75a23abf] | 234 | result.parts.mantisa = ((mant1&(~0x20000000))>>6); /*Clear hidden bit and shift */
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| 235 | result.parts.exp = exp1;
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[b5440cf] | 236 |
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[75a23abf] | 237 | return result;
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[b5440cf] | 238 | };
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| 239 |
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[3af72dc] | 240 | /** Multiply two 32 bit float numbers
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| 241 | *
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| 242 | */
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| 243 | float32 mulFloat32(float32 a, float32 b)
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| 244 | {
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| 245 | float32 result;
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| 246 | __u64 mant1, mant2;
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| 247 | __s32 exp;
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| 248 |
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| 249 | result.parts.sign = a.parts.sign ^ b.parts.sign;
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| 250 |
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| 251 | if ((isFloat32NaN(a))||(isFloat32NaN(b))) {
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| 252 | /* TODO: fix SigNaNs */
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| 253 | if (isFloat32SigNaN(a)) {
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| 254 | result.parts.mantisa = a.parts.mantisa;
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| 255 | result.parts.exp = a.parts.exp;
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| 256 | return result;
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| 257 | };
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| 258 | if (isFloat32SigNaN(b)) { /* TODO: fix SigNaN */
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| 259 | result.parts.mantisa = b.parts.mantisa;
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| 260 | result.parts.exp = b.parts.exp;
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| 261 | return result;
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| 262 | };
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| 263 | /* set NaN as result */
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| 264 | result.parts.mantisa = 0x1;
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| 265 | result.parts.exp = 0xFF;
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| 266 | return result;
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| 267 | };
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| 268 |
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| 269 | if (isFloat32Infinity(a)) {
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| 270 | if (isFloat32Zero(b)) {
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| 271 | /* FIXME: zero * infinity */
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| 272 | result.parts.mantisa = 0x1;
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| 273 | result.parts.exp = 0xFF;
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| 274 | return result;
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| 275 | }
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| 276 | result.parts.mantisa = a.parts.mantisa;
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| 277 | result.parts.exp = a.parts.exp;
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| 278 | return result;
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| 279 | }
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| 280 |
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| 281 | if (isFloat32Infinity(b)) {
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| 282 | if (isFloat32Zero(a)) {
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| 283 | /* FIXME: zero * infinity */
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| 284 | result.parts.mantisa = 0x1;
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| 285 | result.parts.exp = 0xFF;
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| 286 | return result;
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| 287 | }
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| 288 | result.parts.mantisa = b.parts.mantisa;
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| 289 | result.parts.exp = b.parts.exp;
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| 290 | return result;
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| 291 | }
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| 292 |
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| 293 | /* exp is signed so we can easy detect underflow */
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| 294 | exp = a.parts.exp + b.parts.exp;
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| 295 | exp -= FLOAT32_BIAS;
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| 296 |
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| 297 | if (exp >= 0xFF ) {
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| 298 | /* FIXME: overflow */
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| 299 | /* set infinity as result */
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| 300 | result.parts.mantisa = 0x0;
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| 301 | result.parts.exp = 0xFF;
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| 302 | return result;
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| 303 | };
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| 304 |
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| 305 | if (exp < 0) {
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| 306 | /* FIXME: underflow */
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| 307 | /* return signed zero */
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| 308 | result.parts.mantisa = 0x0;
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| 309 | result.parts.exp = 0x0;
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| 310 | return result;
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| 311 | };
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| 312 |
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| 313 | mant1 = a.parts.mantisa;
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| 314 | if (a.parts.exp>0) {
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| 315 | mant1 |= 0x800000;
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| 316 | } else {
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| 317 | ++exp;
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| 318 | };
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| 319 |
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| 320 | mant2 = b.parts.mantisa;
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| 321 | if (b.parts.exp>0) {
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| 322 | mant2 |= 0x800000;
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| 323 | } else {
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| 324 | ++exp;
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| 325 | };
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| 326 |
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| 327 | mant1 <<= 1; /* one bit space for rounding */
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| 328 |
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| 329 | mant1 = mant1 * mant2;
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| 330 | /* round and return */
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| 331 |
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| 332 | while ((exp < 0xFF )&&(mant1 > 0x1FFFFFF )) { /* 0xFFFFFF is 23 bits of mantisa + one more for hidden bit (all shifted 1 bit left)*/
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| 333 | ++exp;
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| 334 | mant1 >>= 1;
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| 335 | };
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| 336 |
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| 337 | /* rounding */
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| 338 | //++mant1; /* FIXME: not works - without it is ok */
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| 339 | mant1 >>= 1; /* shift off rounding space */
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| 340 |
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| 341 | if ((exp < 0xFF )&&(mant1 > 0xFFFFFF )) {
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| 342 | ++exp;
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| 343 | mant1 >>= 1;
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| 344 | };
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| 345 |
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| 346 | if (exp >= 0xFF ) {
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| 347 | /* TODO: fix overflow */
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| 348 | /* return infinity*/
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| 349 | result.parts.exp = 0xFF;
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| 350 | result.parts.mantisa = 0x0;
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| 351 | return result;
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| 352 | }
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| 353 |
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| 354 | exp -= FLOAT32_MANTISA_SIZE;
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| 355 |
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| 356 | if (exp <= FLOAT32_MANTISA_SIZE) {
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| 357 | /* denormalized number */
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| 358 | mant1 >>= 1; /* denormalize */
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| 359 | while ((mant1 > 0) && (exp < 0)) {
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| 360 | mant1 >>= 1;
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| 361 | ++exp;
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| 362 | };
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| 363 | if (mant1 == 0) {
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| 364 | /* FIXME : underflow */
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| 365 | result.parts.exp = 0;
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| 366 | result.parts.mantisa = 0;
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| 367 | return result;
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| 368 | };
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| 369 | };
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| 370 | result.parts.exp = exp;
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| 371 | result.parts.mantisa = mant1 & 0x7FFFFF;
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| 372 |
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| 373 | return result;
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| 374 |
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| 375 | };
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| 376 |
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| 377 |
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