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| 535 | cejka | 1 | |
| 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 | |||
| 30 | #include<softfloat.h> |
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| 31 | |||
| 563 | cejka | 32 | float32 addFloat32(float32 a, float32 b); |
| 33 | float32 subFloat32(float32 a, float32 b); |
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| 34 | inline int isFloat32NaN(float32 f); |
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| 35 | inline int isFloat32SigNaN(float32 f); |
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| 542 | cejka | 36 | |
| 37 | float __addsf3(float a, float b) |
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| 38 | { |
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| 39 | float32 fa, fb; |
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| 563 | cejka | 40 | fa.f=a; |
| 41 | fb.f=b; |
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| 42 | if (fa.parts.sign!=fb.parts.sign) return subFloat32(fa,fb).f; |
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| 43 | return addFloat32(fa,fb).f; |
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| 542 | cejka | 44 | }; |
| 45 | |||
| 46 | float __subsf3(float a, float b) |
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| 47 | { |
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| 48 | float32 fa, fb; |
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| 563 | cejka | 49 | fa.f=a; |
| 50 | fb.f=b; |
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| 51 | if (fa.parts.sign!=fb.parts.sign) return addFloat32(fa,fb).f; |
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| 52 | return subFloat32(fa,fb).f; |
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| 542 | cejka | 53 | }; |
| 54 | |||
| 55 | float __negsf2(float a) |
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| 56 | { |
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| 57 | float32 fa; |
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| 58 | fa.f=a; |
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| 59 | fa.parts.sign=!fa.parts.sign; |
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| 60 | return fa.f; |
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| 61 | }; |
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| 62 | |||
| 63 | double __negdf2(double a) |
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| 64 | { |
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| 65 | float64 fa; |
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| 563 | cejka | 66 | fa.d=a; |
| 542 | cejka | 67 | fa.parts.sign=!fa.parts.sign; |
| 563 | cejka | 68 | return fa.d; |
| 542 | cejka | 69 | }; |
| 70 | |||
| 563 | cejka | 71 | /** Add two Float32 numbers with same signs |
| 72 | */ |
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| 542 | cejka | 73 | float32 addFloat32(float32 a, float32 b) |
| 74 | { |
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| 563 | cejka | 75 | int expdiff; |
| 542 | cejka | 76 | __u32 exp1,exp2,mant1,mant2; |
| 77 | |||
| 78 | expdiff=a.parts.exp - b.parts.exp; |
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| 79 | if (expdiff<0) { |
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| 563 | cejka | 80 | if (isFloat32NaN(b)) { |
| 81 | //TODO: fix SigNaN |
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| 82 | if (isFloat32SigNaN(b)) { |
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| 83 | }; |
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| 84 | return b; |
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| 542 | cejka | 85 | }; |
| 563 | cejka | 86 | |
| 87 | if (b.parts.exp==0xFF) { |
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| 88 | return b; |
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| 89 | } |
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| 90 | |||
| 542 | cejka | 91 | mant1=b.parts.mantisa; |
| 92 | exp1=b.parts.exp; |
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| 93 | mant2=a.parts.mantisa; |
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| 94 | exp2=a.parts.exp; |
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| 95 | expdiff*=-1; |
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| 96 | } else { |
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| 563 | cejka | 97 | if (isFloat32NaN(a)) { |
| 98 | //TODO: fix SigNaN |
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| 99 | if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) { |
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| 100 | }; |
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| 101 | return a; |
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| 542 | cejka | 102 | }; |
| 563 | cejka | 103 | |
| 104 | if (a.parts.exp==0xFF) { |
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| 105 | return a; |
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| 106 | } |
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| 107 | |||
| 542 | cejka | 108 | mant1=a.parts.mantisa; |
| 109 | exp1=a.parts.exp; |
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| 110 | mant2=b.parts.mantisa; |
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| 111 | exp2=b.parts.exp; |
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| 112 | }; |
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| 563 | cejka | 113 | |
| 114 | if (exp1==0) { |
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| 115 | //both are denormalized |
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| 116 | mant1+=mant2; |
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| 117 | if (mant1&0xF00000) { |
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| 118 | a.parts.exp=1; |
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| 119 | }; |
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| 120 | a.parts.mantisa=mant1; |
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| 121 | return a; |
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| 122 | }; |
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| 123 | |||
| 542 | cejka | 124 | // create some space for rounding |
| 125 | mant1<<=6; |
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| 126 | mant2<<=6; |
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| 127 | |||
| 563 | cejka | 128 | mant1|=0x20000000; //add hidden bit |
| 542 | cejka | 129 | |
| 563 | cejka | 130 | |
| 542 | cejka | 131 | if (exp2==0) { |
| 132 | --expdiff; |
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| 133 | } else { |
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| 134 | mant2|=0x20000000; //hidden bit |
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| 135 | }; |
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| 136 | |||
| 137 | mant2>>=expdiff; |
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| 138 | mant1+=mant2; |
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| 139 | done: |
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| 563 | cejka | 140 | if (mant1&0x40000000) { |
| 141 | ++exp1; |
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| 142 | mant1>>=1; |
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| 143 | }; |
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| 144 | |||
| 145 | //rounding - if first bit after mantisa is set then round up |
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| 146 | mant1+=0x20; |
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| 147 | |||
| 542 | cejka | 148 | a.parts.exp=exp1; |
| 149 | a.parts.mantisa=mant1>>6; |
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| 150 | return a; |
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| 151 | }; |
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| 152 | |||
| 563 | cejka | 153 | /** Substract two float32 numbers with same signs |
| 154 | */ |
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| 542 | cejka | 155 | float32 subFloat32(float32 a, float32 b) |
| 156 | { |
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| 157 | |||
| 158 | |||
| 159 | }; |
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| 160 | |||
| 161 | inline int isFloat32NaN(float32 f) |
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| 162 | { /* NaN : exp = 0xff and nonzero mantisa */ |
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| 563 | cejka | 163 | return ((f.parts.exp==0xFF)&&(f.parts.mantisa)); |
| 542 | cejka | 164 | }; |
| 165 | |||
| 166 | inline int isFloat32SigNaN(float32 f) |
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| 167 | { /* SigNaN : exp = 0xff mantisa = 1xxxxx..x (binary), where at least one x is nonzero */ |
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| 563 | cejka | 168 | return ((f.parts.exp==0xFF)&&(f.parts.mantisa>0x400000)); |
| 542 | cejka | 169 | }; |
| 170 |