Last change
on this file since 577 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:
1.2 KB
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1 | |
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2 | /* @(#)z_fabs.c 1.0 98/08/13 */ |
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3 | |
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4 | /* |
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5 | FUNCTION |
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6 | <<fabs>>, <<fabsf>>---absolute value (magnitude) |
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7 | INDEX |
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8 | fabs |
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9 | INDEX |
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10 | fabsf |
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11 | |
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12 | SYNOPSIS |
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13 | #include <math.h> |
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14 | double fabs(double <[x]>); |
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15 | float fabsf(float <[x]>); |
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16 | |
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17 | DESCRIPTION |
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18 | <<fabs>> and <<fabsf>> calculate |
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19 | @tex |
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20 | $|x|$, |
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21 | @end tex |
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22 | the absolute value (magnitude) of the argument <[x]>, by direct |
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23 | manipulation of the bit representation of <[x]>. |
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24 | |
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25 | RETURNS |
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26 | The calculated value is returned. |
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27 | |
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28 | PORTABILITY |
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29 | <<fabs>> is ANSI. |
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30 | <<fabsf>> is an extension. |
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31 | |
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32 | */ |
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33 | |
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34 | /****************************************************************** |
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35 | * Floating-Point Absolute Value |
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36 | * |
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37 | * Input: |
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38 | * x - floating-point number |
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39 | * |
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40 | * Output: |
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41 | * absolute value of x |
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42 | * |
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43 | * Description: |
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44 | * fabs computes the absolute value of a floating point number. |
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45 | * |
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46 | *****************************************************************/ |
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47 | |
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48 | #include "fdlibm.h" |
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49 | #include "zmath.h" |
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50 | |
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51 | #ifndef _DOUBLE_IS_32BITS |
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52 | |
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53 | double |
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54 | fabs (double x) |
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55 | { |
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56 | switch (numtest (x)) |
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57 | { |
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58 | case NAN: |
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59 | errno = EDOM; |
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60 | return (x); |
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61 | case INF: |
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62 | errno = ERANGE; |
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63 | return (x); |
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64 | case 0: |
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65 | return (0.0); |
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66 | default: |
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67 | return (x < 0.0 ? -x : x); |
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68 | } |
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69 | } |
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70 | |
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71 | #endif /* _DOUBLE_IS_32BITS */ |
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