| 1 | /* @(#)s_isnan.c 5.1 93/09/24 */ |
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| 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 | |
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| 13 | /* |
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| 14 | * isnan(x) returns 1 is x is nan, else 0; |
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| 15 | * no branching! |
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| 16 | */ |
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| 17 | |
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| 18 | #include <math.h> |
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| 19 | #include <math_private.h> |
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| 20 | #include <ldbl-classify-compat.h> |
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| 21 | #include <shlib-compat.h> |
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| 22 | #include <stdint.h> |
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| 23 | |
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| 24 | int |
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| 25 | __isnan (double x) |
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| 26 | { |
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| 27 | int64_t hx; |
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| 28 | EXTRACT_WORDS64 (hx, x); |
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| 29 | hx &= UINT64_C (0x7fffffffffffffff); |
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| 30 | hx = UINT64_C (0x7ff0000000000000) - hx; |
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| 31 | return (int)(((uint64_t)hx)>>63); |
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| 32 | } |
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| 33 | hidden_def (__isnan) |
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| 34 | weak_alias (__isnan, isnan) |
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| 35 | #ifdef NO_LONG_DOUBLE |
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| 36 | # if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23) |
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| 37 | compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0); |
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| 38 | # endif |
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| 39 | weak_alias (__isnan, isnanl) |
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| 40 | #endif |
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| 41 | |
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