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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 | |||
572 | cejka | 137 | if (expdiff>24) { |
138 | goto done; |
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139 | }; |
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140 | |||
542 | cejka | 141 | mant2>>=expdiff; |
142 | mant1+=mant2; |
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143 | done: |
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563 | cejka | 144 | if (mant1&0x40000000) { |
145 | ++exp1; |
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146 | mant1>>=1; |
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147 | }; |
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148 | |||
149 | //rounding - if first bit after mantisa is set then round up |
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150 | mant1+=0x20; |
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151 | |||
542 | cejka | 152 | a.parts.exp=exp1; |
153 | a.parts.mantisa=mant1>>6; |
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154 | return a; |
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155 | }; |
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156 | |||
563 | cejka | 157 | /** Substract two float32 numbers with same signs |
158 | */ |
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542 | cejka | 159 | float32 subFloat32(float32 a, float32 b) |
160 | { |
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161 | |||
162 | |||
163 | }; |
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164 | |||
165 | inline int isFloat32NaN(float32 f) |
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166 | { /* NaN : exp = 0xff and nonzero mantisa */ |
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563 | cejka | 167 | return ((f.parts.exp==0xFF)&&(f.parts.mantisa)); |
542 | cejka | 168 | }; |
169 | |||
170 | inline int isFloat32SigNaN(float32 f) |
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171 | { /* SigNaN : exp = 0xff mantisa = 1xxxxx..x (binary), where at least one x is nonzero */ |
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563 | cejka | 172 | return ((f.parts.exp==0xFF)&&(f.parts.mantisa>0x400000)); |
542 | cejka | 173 | }; |
174 |