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3362 | Serge | 1 | /* |
2 | * ==================================================== |
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3 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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4 | * |
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5 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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6 | * Permission to use, copy, modify, and distribute this |
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7 | * software is freely granted, provided that this notice |
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8 | * is preserved. |
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9 | * ==================================================== |
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10 | */ |
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11 | |||
12 | #include "fdlibm.h" |
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13 | |||
14 | #ifdef __STDC__ |
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15 | float roundf(float x) |
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16 | #else |
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17 | float roundf(x) |
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18 | float x; |
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19 | #endif |
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20 | { |
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21 | __uint32_t w; |
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22 | /* Most significant word, least significant word. */ |
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23 | int exponent_less_127; |
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24 | |||
25 | GET_FLOAT_WORD(w, x); |
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26 | |||
27 | /* Extract exponent field. */ |
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28 | exponent_less_127 = (int)((w & 0x7f800000) >> 23) - 127; |
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29 | |||
30 | if (exponent_less_127 < 23) |
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31 | { |
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32 | if (exponent_less_127 < 0) |
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33 | { |
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34 | w &= 0x80000000; |
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35 | if (exponent_less_127 == -1) |
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36 | /* Result is +1.0 or -1.0. */ |
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37 | w |= ((__uint32_t)127 << 23); |
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38 | } |
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39 | else |
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40 | { |
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41 | unsigned int exponent_mask = 0x007fffff >> exponent_less_127; |
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42 | if ((w & exponent_mask) == 0) |
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43 | /* x has an integral value. */ |
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44 | return x; |
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45 | |||
46 | w += 0x00400000 >> exponent_less_127; |
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47 | w &= ~exponent_mask; |
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48 | } |
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49 | } |
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50 | else |
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51 | { |
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52 | if (exponent_less_127 == 128) |
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53 | /* x is NaN or infinite. */ |
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54 | return x + x; |
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55 | else |
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56 | return x; |
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57 | } |
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58 | SET_FLOAT_WORD(x, w); |
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59 | return x; |
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60 | } |
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61 | |||
62 | #ifdef _DOUBLE_IS_32BITS |
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63 | |||
64 | #ifdef __STDC__ |
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65 | double round(double x) |
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66 | #else |
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67 | double round(x) |
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68 | double x; |
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69 | #endif |
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70 | { |
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71 | return (double) roundf((float) x); |
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72 | } |
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73 | |||
74 | #endif /* defined(_DOUBLE_IS_32BITS) */><>>> |