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Rev | Author | Line No. | Line |
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4349 | Serge | 1 | /* sf_floor.c -- float version of s_floor.c. |
2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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3 | */ |
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4 | |||
5 | /* |
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6 | * ==================================================== |
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7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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8 | * |
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9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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10 | * Permission to use, copy, modify, and distribute this |
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11 | * software is freely granted, provided that this notice |
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12 | * is preserved. |
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13 | * ==================================================== |
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14 | */ |
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15 | |||
16 | /* |
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17 | * floorf(x) |
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18 | * Return x rounded toward -inf to integral value |
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19 | * Method: |
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20 | * Bit twiddling. |
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21 | * Exception: |
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22 | * Inexact flag raised if x not equal to floorf(x). |
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23 | */ |
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24 | |||
25 | #include "fdlibm.h" |
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26 | |||
27 | #ifdef __STDC__ |
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28 | static const float huge = 1.0e30; |
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29 | #else |
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30 | static float huge = 1.0e30; |
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31 | #endif |
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32 | |||
33 | #ifdef __STDC__ |
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34 | float floorf(float x) |
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35 | #else |
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36 | float floorf(x) |
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37 | float x; |
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38 | #endif |
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39 | { |
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40 | __int32_t i0,j0; |
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41 | __uint32_t i,ix; |
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42 | GET_FLOAT_WORD(i0,x); |
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43 | ix = (i0&0x7fffffff); |
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44 | j0 = (ix>>23)-0x7f; |
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45 | if(j0<23) { |
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46 | if(j0<0) { /* raise inexact if x != 0 */ |
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47 | if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */ |
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48 | if(i0>=0) {i0=0;} |
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49 | else if(!FLT_UWORD_IS_ZERO(ix)) |
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50 | { i0=0xbf800000;} |
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51 | } |
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52 | } else { |
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53 | i = (0x007fffff)>>j0; |
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54 | if((i0&i)==0) return x; /* x is integral */ |
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55 | if(huge+x>(float)0.0) { /* raise inexact flag */ |
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56 | if(i0<0) i0 += (0x00800000)>>j0; |
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57 | i0 &= (~i); |
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58 | } |
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59 | } |
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60 | } else { |
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61 | if(!FLT_UWORD_IS_FINITE(ix)) return x+x; /* inf or NaN */ |
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62 | else return x; /* x is integral */ |
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63 | } |
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64 | SET_FLOAT_WORD(x,i0); |
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65 | return x; |
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66 | } |
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67 | |||
68 | #ifdef _DOUBLE_IS_32BITS |
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69 | |||
70 | #ifdef __STDC__ |
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71 | double floor(double x) |
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72 | #else |
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73 | double floor(x) |
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74 | double x; |
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75 | #endif |
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76 | { |
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77 | return (double) floorf((float) x); |
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78 | } |
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79 | |||
80 | #endif /* defined(_DOUBLE_IS_32BITS) */0)>1>0)>23)> |