[444] | 1 | |
---|
| 2 | /* @(#)s_copysign.c 5.1 93/09/24 */ |
---|
| 3 | /* |
---|
| 4 | * ==================================================== |
---|
| 5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
---|
| 6 | * |
---|
| 7 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
---|
| 8 | * Permission to use, copy, modify, and distribute this |
---|
| 9 | * software is freely granted, provided that this notice |
---|
| 10 | * is preserved. |
---|
| 11 | * ==================================================== |
---|
| 12 | */ |
---|
| 13 | |
---|
| 14 | /* |
---|
| 15 | FUNCTION |
---|
| 16 | <<copysign>>, <<copysignf>>---sign of <[y]>, magnitude of <[x]> |
---|
| 17 | |
---|
| 18 | INDEX |
---|
| 19 | copysign |
---|
| 20 | INDEX |
---|
| 21 | copysignf |
---|
| 22 | |
---|
| 23 | SYNOPSIS |
---|
| 24 | #include <math.h> |
---|
| 25 | double copysign (double <[x]>, double <[y]>); |
---|
| 26 | float copysignf (float <[x]>, float <[y]>); |
---|
| 27 | |
---|
| 28 | DESCRIPTION |
---|
| 29 | <<copysign>> constructs a number with the magnitude (absolute value) |
---|
| 30 | of its first argument, <[x]>, and the sign of its second argument, |
---|
| 31 | <[y]>. |
---|
| 32 | |
---|
| 33 | <<copysignf>> does the same thing; the two functions differ only in |
---|
| 34 | the type of their arguments and result. |
---|
| 35 | |
---|
| 36 | RETURNS |
---|
| 37 | <<copysign>> returns a <<double>> with the magnitude of |
---|
| 38 | <[x]> and the sign of <[y]>. |
---|
| 39 | <<copysignf>> returns a <<float>> with the magnitude of |
---|
| 40 | <[x]> and the sign of <[y]>. |
---|
| 41 | |
---|
| 42 | PORTABILITY |
---|
| 43 | <<copysign>> is not required by either ANSI C or the System V Interface |
---|
| 44 | Definition (Issue 2). |
---|
| 45 | |
---|
| 46 | */ |
---|
| 47 | |
---|
| 48 | /* |
---|
| 49 | * copysign(double x, double y) |
---|
| 50 | * copysign(x,y) returns a value with the magnitude of x and |
---|
| 51 | * with the sign bit of y. |
---|
| 52 | */ |
---|
| 53 | |
---|
| 54 | #include "fdlibm.h" |
---|
| 55 | |
---|
| 56 | #ifndef _DOUBLE_IS_32BITS |
---|
| 57 | |
---|
| 58 | #ifdef __STDC__ |
---|
| 59 | double copysign(double x, double y) |
---|
| 60 | #else |
---|
| 61 | double copysign(x,y) |
---|
| 62 | double x,y; |
---|
| 63 | #endif |
---|
| 64 | { |
---|
| 65 | __uint32_t hx,hy; |
---|
| 66 | GET_HIGH_WORD(hx,x); |
---|
| 67 | GET_HIGH_WORD(hy,y); |
---|
| 68 | SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000)); |
---|
| 69 | return x; |
---|
| 70 | } |
---|
| 71 | |
---|
| 72 | #endif /* _DOUBLE_IS_32BITS */ |
---|