libjava/java/lang/s_copysign.c

   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 ANSI_SYNOPSIS
  24         #include <math.h>
  25         double copysign (double <[x]>, double <[y]>);
  26         float copysignf (float <[x]>, float <[y]>);
  27
  28 TRAD_SYNOPSIS
  29         #include <math.h>
  30         double copysign (<[x]>, <[y]>)
  31         double <[x]>;
  32         double <[y]>;
  33
  34         float copysignf (<[x]>, <[y]>)
  35         float <[x]>;
  36         float <[y]>;
  37
  38 DESCRIPTION
  39 <<copysign>> constructs a number with the magnitude (absolute value)
  40 of its first argument, <[x]>, and the sign of its second argument,
  41 <[y]>.
  42
  43 <<copysignf>> does the same thing; the two functions differ only in
  44 the type of their arguments and result.
  45
  46 RETURNS
  47 <<copysign>> returns a <<double>> with the magnitude of
  48 <[x]> and the sign of <[y]>.
  49 <<copysignf>> returns a <<float>> with the magnitude of
  50 <[x]> and the sign of <[y]>.
  51
  52 PORTABILITY
  53 <<copysign>> is not required by either ANSI C or the System V Interface
  54 Definition (Issue 2).
  55
  56 */
  57
  58 /*
  59  * copysign(double x, double y)
  60  * copysign(x,y) returns a value with the magnitude of x and
  61  * with the sign bit of y.
  62  */
  63
  64 #include "fdlibm.h"
  65
  66 #ifndef _DOUBLE_IS_32BITS
  67
  68 #ifdef __STDC__
  69         double copysign(double x, double y)
  70 #else
  71         double copysign(x,y)
  72         double x,y;
  73 #endif
  74 {
  75         uint32_t hx,hy;
  76         GET_HIGH_WORD(hx,x);
  77         GET_HIGH_WORD(hy,y);
  78         SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000));
  79         return x;
  80 }
  81
  82 #endif /* _DOUBLE_IS_32BITS */