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| 2 | /*
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| 3 | * Copyright (C) 2005 Josef Cejka
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| 4 | * All rights reserved.
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| 5 | *
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| 6 | * Redistribution and use in source and binary forms, with or without
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| 7 | * modification, are permitted provided that the following conditions
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| 8 | * are met:
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| 9 | *
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| 10 | * - Redistributions of source code must retain the above copyright
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| 11 | * notice, this list of conditions and the following disclaimer.
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| 12 | * - Redistributions in binary form must reproduce the above copyright
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| 13 | * notice, this list of conditions and the following disclaimer in the
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| 14 | * documentation and/or other materials provided with the distribution.
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| 15 | * - The name of the author may not be used to endorse or promote products
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| 16 | * derived from this software without specific prior written permission.
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| 17 | *
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| 18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 28 | */
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| 29 |
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| 30 | #include<softfloat.h>
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| 31 |
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| 32 |
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| 33 | float __addsf3(float a, float b)
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| 34 | {
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| 35 | float32 fa, fb;
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| 36 | a.f=a;
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| 37 | b.f=b;
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| 38 | if (a.parts.sign!=b.parts.sign) return subFloat32(a,b).f;
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| 39 | return addFloat32(a,b).f;
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| 40 | };
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| 41 |
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| 42 | float __subsf3(float a, float b)
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| 43 | {
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| 44 | float32 fa, fb;
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| 45 | a.f=a;
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| 46 | b.f=b;
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| 47 | if (a.parts.sign!=b.parts.sign) return addFloat32(a,b).f;
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| 48 | return subFloat32(a,b).f;
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| 49 | };
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| 50 |
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| 51 | float __negsf2(float a)
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| 52 | {
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| 53 | float32 fa;
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| 54 | fa.f=a;
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| 55 | fa.parts.sign=!fa.parts.sign;
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| 56 | return fa.f;
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| 57 | };
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| 58 |
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| 59 | double __negdf2(double a)
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| 60 | {
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| 61 | float64 fa;
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| 62 | fa.f=a;
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| 63 | fa.parts.sign=!fa.parts.sign;
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| 64 | return fa.f;
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| 65 | };
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| 66 |
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| 67 | float32 addFloat32(float32 a, float32 b)
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| 68 | {
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| 69 | __u32 expdiff;
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| 70 | __u32 exp1,exp2,mant1,mant2;
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| 71 |
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| 72 | expdiff=a.parts.exp - b.parts.exp;
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| 73 | if (expdiff<0) {
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| 74 | if (isFloat32NaN(a)) {
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| 75 | //TODO: fix it
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| 76 | return a;
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| 77 | };
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| 78 |
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| 79 | mant1=b.parts.mantisa;
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| 80 | exp1=b.parts.exp;
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| 81 | mant2=a.parts.mantisa;
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| 82 | exp2=a.parts.exp;
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| 83 | expdiff*=-1;
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| 84 | } else {
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| 85 | if (isFloat32NaN(b)) {
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| 86 | //TODO: fix it
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| 87 | return b;
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| 88 | };
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| 89 | mant1=a.parts.mantisa;
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| 90 | exp1=a.parts.exp;
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| 91 | mant2=b.parts.mantisa;
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| 92 | exp2=b.parts.exp;
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| 93 | };
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| 94 |
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| 95 | // create some space for rounding
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| 96 | mant1<<=6;
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| 97 | mant2<<=6;
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| 98 |
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| 99 | if (exp1!=0) {
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| 100 | mant1|=0x20000000; //add hidden bit
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| 101 | };
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| 102 |
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| 103 | if (exp2==0) {
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| 104 | --expdiff;
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| 105 | } else {
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| 106 | mant2|=0x20000000; //hidden bit
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| 107 | };
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| 108 |
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| 109 |
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| 110 | if (expdiff>24) {
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| 111 | goto done;
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| 112 | };
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| 113 |
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| 114 | mant2>>=expdiff;
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| 115 | mant1+=mant2;
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| 116 | done:
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| 117 | //TODO: round mant1
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| 118 | a.parts.exp=exp1;
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| 119 | a.parts.mantisa=mant1>>6;
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| 120 | return a;
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| 121 | };
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| 122 |
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| 123 | float32 subFloat32(float32 a, float32 b)
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| 124 | {
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| 125 |
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| 126 |
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| 127 | };
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| 128 |
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| 129 | inline int isFloat32NaN(float32 f)
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| 130 | { /* NaN : exp = 0xff and nonzero mantisa */
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| 131 | float32 fa;
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| 132 | fa.f=f;
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| 133 | return ((fa.parts.exp==0xFF)&&(fa.parts.mantisa));
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| 134 | };
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| 135 |
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| 136 | inline int isFloat32SigNaN(float32 f)
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| 137 | { /* SigNaN : exp = 0xff mantisa = 1xxxxx..x (binary), where at least one x is nonzero */
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| 138 | float32 fa;
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| 139 | fa.f=f;
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| 140 | return ((fa.parts.exp==0xFF)&&(fa.parts.mantisa>0x400000));
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| 141 | };
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| 142 |
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