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| 2 | /* @(#)s_copysign.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 | |
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| 14 | /* |
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| 15 | FUNCTION |
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| 16 | <<copysign>>, <<copysignf>>---sign of <[y]>, magnitude of <[x]> |
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| 17 | |
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| 18 | INDEX |
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| 19 | copysign |
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| 20 | INDEX |
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| 21 | copysignf |
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| 22 | |
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| 23 | SYNOPSIS |
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| 24 | #include <math.h> |
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| 25 | double copysign (double <[x]>, double <[y]>); |
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| 26 | float copysignf (float <[x]>, float <[y]>); |
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| 27 | |
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| 28 | DESCRIPTION |
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| 29 | <<copysign>> constructs a number with the magnitude (absolute value) |
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| 30 | of its first argument, <[x]>, and the sign of its second argument, |
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| 31 | <[y]>. |
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| 32 | |
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| 33 | <<copysignf>> does the same thing; the two functions differ only in |
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| 34 | the type of their arguments and result. |
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| 35 | |
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| 36 | RETURNS |
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| 37 | <<copysign>> returns a <<double>> with the magnitude of |
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| 38 | <[x]> and the sign of <[y]>. |
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| 39 | <<copysignf>> returns a <<float>> with the magnitude of |
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| 40 | <[x]> and the sign of <[y]>. |
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| 41 | |
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| 42 | PORTABILITY |
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| 43 | <<copysign>> is not required by either ANSI C or the System V Interface |
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| 44 | Definition (Issue 2). |
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| 45 | |
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| 46 | */ |
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| 47 | |
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| 48 | /* |
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| 49 | * copysign(double x, double y) |
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| 50 | * copysign(x,y) returns a value with the magnitude of x and |
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| 51 | * with the sign bit of y. |
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| 52 | */ |
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| 53 | |
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| 54 | #include "fdlibm.h" |
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| 55 | |
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| 56 | #ifndef _DOUBLE_IS_32BITS |
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| 57 | |
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| 58 | #ifdef __STDC__ |
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| 59 | double copysign(double x, double y) |
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| 60 | #else |
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| 61 | double copysign(x,y) |
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| 62 | double x,y; |
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| 63 | #endif |
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| 64 | { |
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| 65 | __uint32_t hx,hy; |
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| 66 | GET_HIGH_WORD(hx,x); |
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| 67 | GET_HIGH_WORD(hy,y); |
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| 68 | SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000)); |
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| 69 | return x; |
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| 70 | } |
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| 71 | |
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| 72 | #endif /* _DOUBLE_IS_32BITS */ |
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