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| Rev | Author | Line No. | Line |
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| 4349 | Serge | 1 | /* @(#)w_gamma.c 5.1 93/09/24 */ |
| 2 | /* |
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| 3 | * ==================================================== |
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| 4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 5 | * |
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| 6 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 7 | * Permission to use, copy, modify, and distribute this |
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| 8 | * software is freely granted, provided that this notice |
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| 9 | * is preserved. |
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| 10 | * ==================================================== |
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| 11 | */ |
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| 12 | |||
| 13 | /* double gamma(double x) |
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| 14 | * Return the logarithm of the Gamma function of x or the Gamma function of x, |
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| 15 | * depending on the library mode. |
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| 16 | */ |
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| 17 | |||
| 18 | #include "fdlibm.h" |
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| 19 | |||
| 20 | #ifndef _DOUBLE_IS_32BITS |
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| 21 | |||
| 22 | #ifdef __STDC__ |
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| 23 | double tgamma(double x) |
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| 24 | #else |
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| 25 | double tgamma(x) |
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| 26 | double x; |
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| 27 | #endif |
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| 28 | { |
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| 29 | double y; |
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| 30 | int local_signgam; |
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| 31 | y = __ieee754_gamma_r(x,&local_signgam); |
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| 32 | if (local_signgam < 0) y = -y; |
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| 33 | #ifdef _IEEE_LIBM |
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| 34 | return y; |
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| 35 | #else |
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| 36 | if(_LIB_VERSION == _IEEE_) return y; |
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| 37 | |||
| 38 | if(!finite(y)&&finite(x)) { |
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| 39 | if(floor(x)==x&&x<=0.0) |
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| 40 | return __kernel_standard(x,x,41); /* tgamma pole */ |
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| 41 | else |
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| 42 | return __kernel_standard(x,x,40); /* tgamma overflow */ |
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| 43 | } |
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| 44 | return y; |
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| 45 | #endif |
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| 46 | } |
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| 47 | |||
| 48 | #endif /* defined(_DOUBLE_IS_32BITS) */ |