1 | /* |
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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 | |
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12 | #include "fdlibm.h" |
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13 | |
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14 | #ifdef __STDC__ |
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15 | float truncf(float x) |
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16 | #else |
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17 | float truncf(x) |
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18 | float x; |
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19 | #endif |
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20 | { |
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21 | __int32_t signbit, w, exponent_less_127; |
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22 | |
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23 | GET_FLOAT_WORD(w,x); |
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24 | |
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25 | /* Extract sign bit. */ |
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26 | signbit = w & 0x80000000; |
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27 | |
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28 | /* Extract exponent field. */ |
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29 | exponent_less_127 = ((w & 0x7f800000) >> 23) - 127; |
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30 | |
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31 | if (exponent_less_127 < 23) |
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32 | { |
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33 | if (exponent_less_127 < 0) |
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34 | { |
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35 | /* -1 < x < 1, so result is +0 or -0. */ |
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36 | SET_FLOAT_WORD(x, signbit); |
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37 | } |
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38 | else |
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39 | { |
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40 | SET_FLOAT_WORD(x, signbit | (w & ~(0x007fffff >> exponent_less_127))); |
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41 | } |
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42 | } |
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43 | else |
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44 | { |
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45 | if (exponent_less_127 == 255) |
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46 | /* x is NaN or infinite. */ |
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47 | return x + x; |
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48 | |
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49 | /* All bits in the fraction field are relevant. */ |
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50 | } |
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51 | return x; |
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52 | } |
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53 | |
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54 | #ifdef _DOUBLE_IS_32BITS |
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55 | |
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56 | #ifdef __STDC__ |
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57 | double trunc(double x) |
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58 | #else |
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59 | double trunc(x) |
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60 | double x; |
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61 | #endif |
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62 | { |
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63 | return (double) truncf((float) x); |
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64 | } |
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65 | |
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66 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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