Last change
on this file since 559 was
444,
checked in by satin@…, 6 years ago
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add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
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File size:
1.1 KB
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Rev | Line | |
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[444] | 1 | |
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| 2 | /* @(#)z_numtest.c 1.0 98/08/13 */ |
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| 3 | /****************************************************************** |
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| 4 | * Numtest |
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| 5 | * |
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| 6 | * Input: |
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| 7 | * x - pointer to a floating point value |
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| 8 | * |
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| 9 | * Output: |
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| 10 | * An integer that indicates what kind of number was passed in: |
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| 11 | * NUM = 3 - a finite value |
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| 12 | * NAN = 2 - not a number |
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| 13 | * INF = 1 - an infinite value |
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| 14 | * 0 - zero |
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| 15 | * |
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| 16 | * Description: |
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| 17 | * This routine returns an integer that indicates the character- |
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| 18 | * istics of the number that was passed in. |
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| 19 | * |
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| 20 | *****************************************************************/ |
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| 21 | |
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| 22 | #include "fdlibm.h" |
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| 23 | #include "zmath.h" |
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| 24 | |
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| 25 | #ifndef _DOUBLE_IS_32BITS |
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| 26 | |
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| 27 | int |
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| 28 | numtest (double x) |
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| 29 | { |
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| 30 | __uint32_t hx, lx; |
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| 31 | int exp; |
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| 32 | |
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| 33 | EXTRACT_WORDS (hx, lx, x); |
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| 34 | |
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| 35 | exp = (hx & 0x7ff00000) >> 20; |
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| 36 | |
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| 37 | /* Check for a zero input. */ |
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| 38 | if (x == 0.0) |
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| 39 | { |
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| 40 | return (0); |
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| 41 | } |
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| 42 | |
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| 43 | /* Check for not a number or infinity. */ |
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| 44 | if (exp == 0x7ff) |
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| 45 | { |
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| 46 | if(hx & 0xf0000 || lx) |
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| 47 | return (NAN); |
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| 48 | else |
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| 49 | return (INF); |
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| 50 | } |
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| 51 | |
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| 52 | /* Otherwise it's a finite value. */ |
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| 53 | else |
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| 54 | return (NUM); |
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| 55 | } |
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| 56 | |
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| 57 | #endif /* _DOUBLE_IS_32BITS */ |
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