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731 cejka 1
/*
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 * Copyright (C) 2005 Josef Cejka
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#include<sftypes.h>
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#include<add.h>
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#include<comparison.h>
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/** Add two Float32 numbers with same signs
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 */
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float32 addFloat32(float32 a, float32 b)
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{
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    int expdiff;
804 cejka 38
    __u32 exp1, exp2,frac1, frac2;
731 cejka 39
 
732 cejka 40
    expdiff = a.parts.exp - b.parts.exp;
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    if (expdiff < 0) {
731 cejka 42
        if (isFloat32NaN(b)) {
804 cejka 43
            /* TODO: fix SigNaN */
731 cejka 44
            if (isFloat32SigNaN(b)) {
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            };
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            return b;
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        };
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732 cejka 50
        if (b.parts.exp == FLOAT32_MAX_EXPONENT) {
731 cejka 51
            return b;
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        }
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804 cejka 54
        frac1 = b.parts.fraction;
732 cejka 55
        exp1 = b.parts.exp;
804 cejka 56
        frac2 = a.parts.fraction;
732 cejka 57
        exp2 = a.parts.exp;
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        expdiff *= -1;
731 cejka 59
    } else {
804 cejka 60
        if ((isFloat32NaN(a)) || (isFloat32NaN(b))) {
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            /* TODO: fix SigNaN */
732 cejka 62
            if (isFloat32SigNaN(a) || isFloat32SigNaN(b)) {
731 cejka 63
            };
804 cejka 64
            return (isFloat32NaN(a)?a:b);
731 cejka 65
        };
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732 cejka 67
        if (a.parts.exp == FLOAT32_MAX_EXPONENT) {
731 cejka 68
            return a;
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        }
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804 cejka 71
        frac1 = a.parts.fraction;
732 cejka 72
        exp1 = a.parts.exp;
804 cejka 73
        frac2 = b.parts.fraction;
732 cejka 74
        exp2 = b.parts.exp;
731 cejka 75
    };
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77
    if (exp1 == 0) {
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        /* both are denormalized */
804 cejka 79
        frac1 += frac2;
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        if (frac1 & FLOAT32_HIDDEN_BIT_MASK ) {
731 cejka 81
            /* result is not denormalized */
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            a.parts.exp = 1;
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        };
804 cejka 84
        a.parts.fraction = frac1;
731 cejka 85
        return a;
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    };
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804 cejka 88
    frac1 |= FLOAT32_HIDDEN_BIT_MASK; /* add hidden bit */
731 cejka 89
 
90
    if (exp2 == 0) {
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        /* second operand is denormalized */
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        --expdiff; 
93
    } else {
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        /* add hidden bit to second operand */
804 cejka 95
        frac2 |= FLOAT32_HIDDEN_BIT_MASK;
731 cejka 96
    };
97
 
98
    /* create some space for rounding */
804 cejka 99
    frac1 <<= 6;
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    frac2 <<= 6;
731 cejka 101
 
804 cejka 102
    if (expdiff < (FLOAT32_FRACTION_SIZE + 2) ) {
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        frac2 >>= expdiff;
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        frac1 += frac2;
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        };
731 cejka 106
 
804 cejka 107
    if (frac1 & (FLOAT32_HIDDEN_BIT_MASK << 7) ) {
731 cejka 108
        ++exp1;
804 cejka 109
        frac1 >>= 1;
731 cejka 110
    };
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804 cejka 112
    /* rounding - if first bit after fraction is set then round up */
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    frac1 += (0x1 << 5);
731 cejka 114
 
804 cejka 115
    if (frac1 & (FLOAT32_HIDDEN_BIT_MASK << 7)) {
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        /* rounding overflow */
731 cejka 117
        ++exp1;
804 cejka 118
        frac1 >>= 1;
731 cejka 119
    };
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804 cejka 121
    if ((a.parts.exp == FLOAT32_MAX_EXPONENT ) || (a.parts.exp < exp1)) {
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            /* overflow - set infinity as result */
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            a.parts.exp = FLOAT32_MAX_EXPONENT;
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            a.parts.fraction = 0;
125
            return a;
126
            }
127
 
731 cejka 128
    a.parts.exp = exp1;
129
 
130
    /*Clear hidden bit and shift */
804 cejka 131
    a.parts.fraction = ((frac1 >> 6) & (~FLOAT32_HIDDEN_BIT_MASK)) ;
731 cejka 132
    return a;
133
}
134
 
135
 
136
/** Add two Float64 numbers with same signs
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 */
138
float64 addFloat64(float64 a, float64 b)
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{
140
    int expdiff;
734 cejka 141
    __u32 exp1, exp2;
804 cejka 142
    __u64 frac1, frac2;
731 cejka 143
 
732 cejka 144
    expdiff = a.parts.exp - b.parts.exp;
145
    if (expdiff < 0) {
731 cejka 146
        if (isFloat64NaN(b)) {
804 cejka 147
            /* TODO: fix SigNaN */
731 cejka 148
            if (isFloat64SigNaN(b)) {
149
            };
150
 
151
            return b;
152
        };
153
 
154
        /* b is infinity and a not */  
732 cejka 155
        if (b.parts.exp == FLOAT64_MAX_EXPONENT ) {
731 cejka 156
            return b;
157
        }
158
 
804 cejka 159
        frac1 = b.parts.fraction;
732 cejka 160
        exp1 = b.parts.exp;
804 cejka 161
        frac2 = a.parts.fraction;
732 cejka 162
        exp2 = a.parts.exp;
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        expdiff *= -1;
731 cejka 164
    } else {
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        if (isFloat64NaN(a)) {
804 cejka 166
            /* TODO: fix SigNaN */
732 cejka 167
            if (isFloat64SigNaN(a) || isFloat64SigNaN(b)) {
731 cejka 168
            };
169
            return a;
170
        };
171
 
172
        /* a is infinity and b not */
732 cejka 173
        if (a.parts.exp == FLOAT64_MAX_EXPONENT ) {
731 cejka 174
            return a;
175
        }
176
 
804 cejka 177
        frac1 = a.parts.fraction;
731 cejka 178
        exp1 = a.parts.exp;
804 cejka 179
        frac2 = b.parts.fraction;
731 cejka 180
        exp2 = b.parts.exp;
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    };
182
 
183
    if (exp1 == 0) {
184
        /* both are denormalized */
804 cejka 185
        frac1 += frac2;
186
        if (frac1 & FLOAT64_HIDDEN_BIT_MASK) {
731 cejka 187
            /* result is not denormalized */
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            a.parts.exp = 1;
189
        };
804 cejka 190
        a.parts.fraction = frac1;
731 cejka 191
        return a;
192
    };
193
 
804 cejka 194
    /* add hidden bit - frac1 is sure not denormalized */
195
    frac1 |= FLOAT64_HIDDEN_BIT_MASK;
731 cejka 196
 
197
    /* second operand ... */
198
    if (exp2 == 0) {
199
        /* ... is denormalized */
200
        --expdiff; 
201
    } else {
202
        /* is not denormalized */
804 cejka 203
        frac2 |= FLOAT64_HIDDEN_BIT_MASK;
731 cejka 204
    };
205
 
206
    /* create some space for rounding */
804 cejka 207
    frac1 <<= 6;
208
    frac2 <<= 6;
731 cejka 209
 
804 cejka 210
    if (expdiff < (FLOAT64_FRACTION_SIZE + 2) ) {
211
        frac2 >>= expdiff;
212
        frac1 += frac2;
213
        };
731 cejka 214
 
804 cejka 215
    if (frac1 & (FLOAT64_HIDDEN_BIT_MASK << 7) ) {
731 cejka 216
        ++exp1;
804 cejka 217
        frac1 >>= 1;
731 cejka 218
    };
219
 
804 cejka 220
    /* rounding - if first bit after fraction is set then round up */
221
    frac1 += (0x1 << 5);
731 cejka 222
 
804 cejka 223
    if (frac1 & (FLOAT64_HIDDEN_BIT_MASK << 7)) {
224
        /* rounding overflow */
731 cejka 225
        ++exp1;
804 cejka 226
        frac1 >>= 1;
731 cejka 227
    };
228
 
804 cejka 229
    if ((a.parts.exp == FLOAT64_MAX_EXPONENT ) || (a.parts.exp < exp1)) {
230
            /* overflow - set infinity as result */
231
            a.parts.exp = FLOAT64_MAX_EXPONENT;
232
            a.parts.fraction = 0;
233
            return a;
234
            }
235
 
731 cejka 236
    a.parts.exp = exp1;
237
    /*Clear hidden bit and shift */
804 cejka 238
    a.parts.fraction = ( (frac1 >> 6 ) & (~FLOAT64_HIDDEN_BIT_MASK));
731 cejka 239
    return a;
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}
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