libm/powerpc/classic/s_copysign.c

   1 /*******************************************************************************
   2 *                                                                              *
   3 *      File sign.c,                                                            *
   4 *      Functions copysign and __signbitd.                                                    *
   5 *      For PowerPC based machines.                                             *
   6 *                                                                              *
   7 *      Copyright © 1991, 2001 Apple Computer, Inc.  All rights reserved.       *
   8 *                                                                              *
   9 *      Written by Ali Sazegari, started on June 1991.                          *
  10 *                                                                              *
  11 *      August    26 1991: no CFront Version 1.1d17 warnings.                   *
  12 *      September 06 1991: passes the test suite with invalid raised on         *
  13 *                         signaling nans.  sane rom code behaves the same.     *
  14 *      September 24 1992: took the Ò#include support.hÓ out.                   *
  15 *      Dcember   02 1992: PowerPC port.                                        *
  16 *      July      20 1994: __fabs added                                         *
  17 *      July      21 1994: deleted unnecessary functions: neg, COPYSIGNnew,     *
  18 *                         and SIGNNUMnew.                                      *
  19 *        April     11 2001: first port to os x using gcc.                                *
  20 *                                 removed fabs and deffered to gcc for direct          *
  21 *                                 instruction generation.                                        *
  22 *                                                                              *
  23 *******************************************************************************/
  24
  25 #include <math.h>
  26 #include "../fp_private.h"
  27
  28 /*******************************************************************************
  29 *                                                                              *
  30 *     Function copysign.                                                       *
  31 *     Implementation of copysign for the PowerPC.                              *
  32 *                                                                              *
  33 ********************************************************************************
  34 *     Note: The order of the operands in this function is reversed from that   *
  35 *     suggested in the IEEE standard 754.                                      *
  36 *******************************************************************************/
  37
  38 libm_hidden_proto(copysign)
  39 double copysign ( double arg2, double arg1 )
  40       {
  41       union
  42             {
  43             dHexParts hex;
  44             double dbl;
  45             } x, y;
  46
  47 /*******************************************************************************
  48 *     No need to flush NaNs out.                                               *
  49 *******************************************************************************/
  50
  51       x.dbl = arg1;
  52       y.dbl = arg2;
  53
  54       y.hex.high = y.hex.high & 0x7FFFFFFF;
  55       y.hex.high = ( y.hex.high | ( x.hex.high & dSgnMask ) );
  56
  57       return y.dbl;
  58       }
  59 libm_hidden_def(copysign)