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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 | 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 | DESCRIPTION |
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| 29 | The <<fmod>> and <<fmodf>> functions compute the floating-point |
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| 30 | remainder of <[x]>/<[y]> (<[x]> modulo <[y]>). |
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| 31 | |
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| 32 | RETURNS |
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| 33 | The <<fmod>> function returns the value |
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| 34 | @ifnottex |
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| 35 | <[x]>-<[i]>*<[y]>, |
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| 36 | @end ifnottex |
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| 37 | @tex |
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| 38 | $x-i\times y$, |
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| 39 | @end tex |
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| 40 | for the largest integer <[i]> such that, if <[y]> is nonzero, the |
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| 41 | result has the same sign as <[x]> and magnitude less than the |
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| 42 | magnitude of <[y]>. |
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| 43 | |
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| 44 | <<fmod(<[x]>,0)>> returns NaN, and sets <<errno>> to <<EDOM>>. |
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| 45 | |
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| 46 | You can modify error treatment for these functions using <<matherr>>. |
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| 47 | |
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| 48 | PORTABILITY |
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| 49 | <<fmod>> is ANSI C. <<fmodf>> is an extension. |
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| 50 | */ |
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| 51 | |
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| 52 | /* |
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| 53 | * wrapper fmod(x,y) |
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| 54 | */ |
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| 55 | |
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| 56 | #include "fdlibm.h" |
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| 57 | #include <errno.h> |
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| 58 | |
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| 59 | #ifndef _DOUBLE_IS_32BITS |
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| 60 | |
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| 61 | #ifdef __STDC__ |
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| 62 | double fmod(double x, double y) /* wrapper fmod */ |
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| 63 | #else |
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| 64 | double fmod(x,y) /* wrapper fmod */ |
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| 65 | double x,y; |
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| 66 | #endif |
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| 67 | { |
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| 68 | #ifdef _IEEE_LIBM |
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| 69 | return __ieee754_fmod(x,y); |
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| 70 | #else |
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| 71 | double z; |
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| 72 | struct exception exc; |
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| 73 | z = __ieee754_fmod(x,y); |
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| 74 | if(_LIB_VERSION == _IEEE_ ||isnan(y)||isnan(x)) return z; |
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| 75 | if(y==0.0) { |
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| 76 | /* fmod(x,0) */ |
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| 77 | exc.type = DOMAIN; |
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| 78 | exc.name = "fmod"; |
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| 79 | exc.arg1 = x; |
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| 80 | exc.arg2 = y; |
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| 81 | exc.err = 0; |
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| 82 | if (_LIB_VERSION == _SVID_) |
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| 83 | exc.retval = x; |
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| 84 | else |
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| 85 | exc.retval = 0.0/0.0; |
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| 86 | if (_LIB_VERSION == _POSIX_) |
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| 87 | errno = EDOM; |
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| 88 | else if (!matherr(&exc)) { |
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| 89 | errno = EDOM; |
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| 90 | } |
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| 91 | if (exc.err != 0) |
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| 92 | errno = exc.err; |
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| 93 | return exc.retval; |
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| 94 | } else |
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| 95 | return z; |
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| 96 | #endif |
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| 97 | } |
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| 98 | |
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| 99 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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