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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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 */
28
 
29
#include<sftypes.h>
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#include<add.h>
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#include<comparison.h>
32
 
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/** Add two Float32 numbers with same signs
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 */
35
float32 addFloat32(float32 a, float32 b)
36
{
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	int expdiff;
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	__u32 exp1, exp2,mant1, mant2;
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732 cejka 40
	expdiff = a.parts.exp - b.parts.exp;
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	if (expdiff < 0) {
731 cejka 42
		if (isFloat32NaN(b)) {
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			//TODO: fix SigNaN
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			if (isFloat32SigNaN(b)) {
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			};
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47
			return b;
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		};
49
 
732 cejka 50
		if (b.parts.exp == FLOAT32_MAX_EXPONENT) { 
731 cejka 51
			return b;
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		}
53
 
732 cejka 54
		mant1 = b.parts.mantisa;
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		exp1 = b.parts.exp;
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		mant2 = a.parts.mantisa;
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		exp2 = a.parts.exp;
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		expdiff *= -1;
731 cejka 59
	} else {
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		if (isFloat32NaN(a)) {
61
			//TODO: fix SigNaN
732 cejka 62
			if (isFloat32SigNaN(a) || isFloat32SigNaN(b)) {
731 cejka 63
			};
64
			return a;
65
		};
66
 
732 cejka 67
		if (a.parts.exp == FLOAT32_MAX_EXPONENT) { 
731 cejka 68
			return a;
69
		}
70
 
732 cejka 71
		mant1 = a.parts.mantisa;
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		exp1 = a.parts.exp;
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		mant2 = b.parts.mantisa;
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		exp2 = b.parts.exp;
731 cejka 75
	};
76
 
77
	if (exp1 == 0) {
78
		/* both are denormalized */
79
		mant1 += mant2;
80
		if (mant1 & FLOAT32_HIDDEN_BIT_MASK ) {
81
			/* result is not denormalized */
82
			a.parts.exp = 1;
83
		};
84
		a.parts.mantisa = mant1;
85
		return a;
86
	};
87
 
88
	mant1 |= FLOAT32_HIDDEN_BIT_MASK; //add hidden bit
89
 
90
	if (exp2 == 0) {
91
		/* second operand is denormalized */
92
		--expdiff;	
93
	} else {
94
		/* add hidden bit to second operand */
95
		mant2 |= FLOAT32_HIDDEN_BIT_MASK; 
96
	};
97
 
98
	/* create some space for rounding */
99
	mant1 <<= 6;
100
	mant2 <<= 6;
101
 
732 cejka 102
	if (expdiff > (FLOAT32_MANTISA_SIZE + 1) ) {
731 cejka 103
	     goto done;	
104
	     };
105
 
732 cejka 106
	mant2 >>= expdiff;
107
	mant1 += mant2;
731 cejka 108
done:
732 cejka 109
	if (mant1 & (FLOAT32_HIDDEN_BIT_MASK << 7) ) {
731 cejka 110
		++exp1;
111
		mant1 >>= 1;
112
	};
113
 
114
	/* rounding - if first bit after mantisa is set then round up */
115
	mant1 += (0x1 << 5);
116
 
732 cejka 117
	if (mant1 & (FLOAT32_HIDDEN_BIT_MASK << 7)) { 
731 cejka 118
		++exp1;
732 cejka 119
		mant1 >>= 1;
731 cejka 120
	};
121
 
122
	a.parts.exp = exp1;
123
 
124
	/*Clear hidden bit and shift */
732 cejka 125
	a.parts.mantisa = ((mant1 >> 6) & (~FLOAT32_HIDDEN_BIT_MASK)) ; 
731 cejka 126
	return a;
127
}
128
 
129
 
130
/** Add two Float64 numbers with same signs
131
 */
132
float64 addFloat64(float64 a, float64 b)
133
{
134
	int expdiff;
734 cejka 135
	__u32 exp1, exp2;
136
	__u64 mant1, mant2;
731 cejka 137
 
732 cejka 138
	expdiff = a.parts.exp - b.parts.exp;
139
	if (expdiff < 0) {
731 cejka 140
		if (isFloat64NaN(b)) {
141
			//TODO: fix SigNaN
142
			if (isFloat64SigNaN(b)) {
143
			};
144
 
145
			return b;
146
		};
147
 
148
		/* b is infinity and a not */	
732 cejka 149
		if (b.parts.exp == FLOAT64_MAX_EXPONENT ) { 
731 cejka 150
			return b;
151
		}
152
 
732 cejka 153
		mant1 = b.parts.mantisa;
154
		exp1 = b.parts.exp;
155
		mant2 = a.parts.mantisa;
156
		exp2 = a.parts.exp;
157
		expdiff *= -1;
731 cejka 158
	} else {
159
		if (isFloat64NaN(a)) {
160
			//TODO: fix SigNaN
732 cejka 161
			if (isFloat64SigNaN(a) || isFloat64SigNaN(b)) {
731 cejka 162
			};
163
			return a;
164
		};
165
 
166
		/* a is infinity and b not */
732 cejka 167
		if (a.parts.exp == FLOAT64_MAX_EXPONENT ) { 
731 cejka 168
			return a;
169
		}
170
 
171
		mant1 = a.parts.mantisa;
172
		exp1 = a.parts.exp;
173
		mant2 = b.parts.mantisa;
174
		exp2 = b.parts.exp;
175
	};
176
 
177
	if (exp1 == 0) {
178
		/* both are denormalized */
179
		mant1 += mant2;
180
		if (mant1 & FLOAT64_HIDDEN_BIT_MASK) { 
181
			/* result is not denormalized */
182
			a.parts.exp = 1;
183
		};
184
		a.parts.mantisa = mant1;
185
		return a;
186
	};
187
 
188
	/* add hidden bit - mant1 is sure not denormalized */
189
	mant1 |= FLOAT64_HIDDEN_BIT_MASK;
190
 
191
	/* second operand ... */
192
	if (exp2 == 0) {
193
		/* ... is denormalized */
194
		--expdiff;	
195
	} else {
196
		/* is not denormalized */
197
		mant2 |= FLOAT64_HIDDEN_BIT_MASK;
198
	};
199
 
200
	/* create some space for rounding */
201
	mant1 <<= 6;
202
	mant2 <<= 6;
203
 
732 cejka 204
	if (expdiff > (FLOAT64_MANTISA_SIZE + 1) ) {
731 cejka 205
	     goto done;	
206
	     };
207
 
208
	mant2 >>= expdiff;
209
	mant1 += mant2;
210
done:
732 cejka 211
	if (mant1 & (FLOAT64_HIDDEN_BIT_MASK << 7) ) {
731 cejka 212
		++exp1;
213
		mant1 >>= 1;
214
	};
215
 
216
	/* rounding - if first bit after mantisa is set then round up */
217
	mant1 += (0x1 << 5); 
218
 
732 cejka 219
	if (mant1 & (FLOAT64_HIDDEN_BIT_MASK << 7)) { 
731 cejka 220
		++exp1;
732 cejka 221
		mant1 >>= 1;
731 cejka 222
	};
223
 
224
	a.parts.exp = exp1;
225
	/*Clear hidden bit and shift */
732 cejka 226
	a.parts.mantisa = ( (mant1 >> 6 ) & (~FLOAT64_HIDDEN_BIT_MASK));
731 cejka 227
	return a;
228
}
229
 
230