1 /* S_CPYSGN.C

     2  * 

     3  * Portions Copyright (c) 1993-1999 Nokia Corporation and/or its subsidiary(-ies).

     4  * All rights reserved.

     5  */

     6 

     7 

     8 /* @(#)s_copysign.c 5.1 93/09/24 */

     9 /*

    10  * ====================================================

    11  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

    12  *

    13  * Developed at SunPro, a Sun Microsystems, Inc. business.

    14  * Permission to use, copy, modify, and distribute this

    15  * software is freely granted, provided that this notice 

    16  * is preserved.

    17  * ====================================================

    18  */

    19 

    20 /*

    21 FUNCTION

    22 <<copysign>>, <<copysignf>>---sign of <[y]>, magnitude of <[x]>

    23 

    24 INDEX

    25 	copysign

    26 INDEX

    27 	copysignf

    28 

    29 ANSI_SYNOPSIS

    30 	#include <math.h>

    31 	double copysign (double <[x]>, double <[y]>);

    32 	float copysignf (float <[x]>, float <[y]>);

    33 

    34 TRAD_SYNOPSIS

    35 	#include <math.h>

    36 	double copysign (<[x]>, <[y]>)

    37 	double <[x]>;

    38 	double <[y]>;

    39 

    40 	float copysignf (<[x]>, <[y]>)

    41 	float <[x]>;

    42 	float <[y]>;

    43 

    44 DESCRIPTION

    45 <<copysign>> constructs a number with the magnitude (absolute value)

    46 of its first argument, <[x]>, and the sign of its second argument,

    47 <[y]>.

    48 

    49 <<copysignf>> does the same thing; the two functions differ only in

    50 the type of their arguments and result.

    51 

    52 RETURNS

    53 <<copysign>> returns a <<double>> with the magnitude of

    54 <[x]> and the sign of <[y]>.

    55 <<copysignf>> returns a <<float>> with the magnitude of

    56 <[x]> and the sign of <[y]>.

    57 

    58 PORTABILITY

    59 <<copysign>> is not required by either ANSI C or the System V Interface

    60 Definition (Issue 2).

    61 

    62 */

    63 

    64 /*

    65  * copysign(double x, double y)

    66  * copysign(x,y) returns a value with the magnitude of x and

    67  * with the sign bit of y.

    68  */

    69 

    70 #include "FDLIBM.H"

    71 

    72 /**

    73 Constructs a number with the magnitude (absolute value)

    74 of its first argument, x, and the sign of its second argument y.

    75 @return a value with the magnitude of x and with the sign bit of y.

    76 @param x magnitude

    77 @param y sign bit

    78 */

    79 EXPORT_C double copysign(double x, double y) __SOFTFP

    80 {

    81 	__uint32_t hx,hy;

    82 	GET_HIGH_WORD(hx,x);

    83 	GET_HIGH_WORD(hy,y);

    84 	SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000));

    85         return x;

    86 }