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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */ |
| 2 | /* @(#)s_isnan.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 | |||
| 14 | #if defined(LIBM_SCCS) && !defined(lint) |
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| 15 | static char rcsid[] = "$Id: s_isnan.c,v 1.6 1994/08/18 23:06:54 jtc Exp $"; |
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| 16 | #endif |
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| 17 | |||
| 18 | /* |
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| 19 | * isnan(x) returns 1 is x is nan, else 0; |
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| 20 | * no branching! |
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| 21 | */ |
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| 22 | |||
| 23 | #include "math.h" |
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| 24 | #include "math_private.h" |
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| 25 | |||
| 26 | #ifdef __STDC__ |
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| 27 | int isnan(double x) |
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| 28 | #else |
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| 29 | int isnan(x) |
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| 30 | double x; |
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| 31 | #endif |
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| 32 | { |
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| 33 | int32_t hx,lx; |
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| 34 | EXTRACT_WORDS(hx,lx,x); |
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| 35 | hx &= 0x7fffffff; |
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| 36 | hx |= (u_int32_t)(lx|(-lx))>>31; |
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| 37 | hx = 0x7ff00000 - hx; |
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| 38 | return (int)((u_int32_t)(hx))>>31; |
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| 39 | } |