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2 | /* @(#)w_fmod.c 5.1 93/09/24 */
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3 | /*
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4 | * ====================================================
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5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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6 | *
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7 | * Developed at SunPro, a Sun Microsystems, Inc. business.
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8 | * Permission to use, copy, modify, and distribute this
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9 | * software is freely granted, provided that this notice
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10 | * is preserved.
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11 | * ====================================================
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12 | */
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13 |
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14 | /*
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15 | FUNCTION
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16 | <<fmod>>, <<fmodf>>---floating-point remainder (modulo)
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17 |
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18 | INDEX
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19 | fmod
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20 | INDEX
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21 | fmodf
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22 |
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23 | ANSI_SYNOPSIS
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24 | #include <math.h>
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25 | double fmod(double <[x]>, double <[y]>)
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26 | float fmodf(float <[x]>, float <[y]>)
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27 |
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28 | TRAD_SYNOPSIS
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29 | #include <math.h>
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30 | double fmod(<[x]>, <[y]>)
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31 | double (<[x]>, <[y]>);
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32 |
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33 | float fmodf(<[x]>, <[y]>)
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34 | float (<[x]>, <[y]>);
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35 |
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36 | DESCRIPTION
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37 | The <<fmod>> and <<fmodf>> functions compute the floating-point
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38 | remainder of <[x]>/<[y]> (<[x]> modulo <[y]>).
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39 |
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40 | RETURNS
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41 | The <<fmod>> function returns the value
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42 | @ifinfo
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43 | <[x]>-<[i]>*<[y]>,
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44 | @end ifinfo
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45 | @tex
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46 | $x-i\times y$,
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47 | @end tex
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48 | for the largest integer <[i]> such that, if <[y]> is nonzero, the
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49 | result has the same sign as <[x]> and magnitude less than the
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50 | magnitude of <[y]>.
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51 |
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52 | <<fmod(<[x]>,0)>> returns NaN, and sets <<errno>> to <<EDOM>>.
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53 |
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54 | You can modify error treatment for these functions using <<matherr>>.
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55 |
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56 | PORTABILITY
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57 | <<fmod>> is ANSI C. <<fmodf>> is an extension.
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58 | */
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59 |
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60 | /*
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61 | * wrapper fmod(x,y)
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62 | */
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63 |
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64 | #include "fdlibm.h"
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65 | #include <errno.h>
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66 |
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67 | #ifndef _DOUBLE_IS_32BITS
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68 |
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69 | #ifdef __STDC__
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70 | double fmod(double x, double y) /* wrapper fmod */
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71 | #else
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72 | double fmod(x,y) /* wrapper fmod */
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73 | double x,y;
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74 | #endif
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75 | {
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76 | #ifdef _IEEE_LIBM
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77 | return __ieee754_fmod(x,y);
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78 | #else
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79 | double z;
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80 | struct exception exc;
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81 | z = __ieee754_fmod(x,y);
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82 | if(_LIB_VERSION == _IEEE_ ||isnan(y)||isnan(x)) return z;
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83 | if(y==0.0) {
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84 | /* fmod(x,0) */
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85 | exc.type = DOMAIN;
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86 | exc.name = "fmod";
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87 | exc.arg1 = x;
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88 | exc.arg2 = y;
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89 | exc.err = 0;
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90 | if (_LIB_VERSION == _SVID_)
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91 | exc.retval = x;
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92 | else
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93 | exc.retval = 0.0/0.0;
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94 | if (_LIB_VERSION == _POSIX_)
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95 | errno = EDOM;
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96 | else if (!matherr(&exc)) {
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97 | errno = EDOM;
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98 | }
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99 | if (exc.err != 0)
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100 | errno = exc.err;
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101 | return exc.retval;
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102 | } else
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103 | return z;
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104 | #endif
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105 | }
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106 |
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107 | #endif /* defined(_DOUBLE_IS_32BITS) */
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