Move powerpc specific optimizations (courtesy of apple) to powerpc

subdir.  Put together a theoretical framework for adding arch specific
optimizations.  Havn't tried this yet but it looks correct...
 -Erik

1 files changed, 56 insertions, 0 deletions

diff --git a/libm/powerpc/sign.c b/libm/powerpc/sign.c
new file mode 100644
index 000000000..0bf2f3829
--- /dev/null
+++ b/libm/powerpc/sign.c
@@ -0,0 +1,56 @@
+/*******************************************************************************
+*                                                                              *
+*      File sign.c,                                                            *
+*      Functions copysign and __signbitd.					             *
+*      For PowerPC based machines.                                             *
+*                                                                              *
+*      Copyright © 1991, 2001 Apple Computer, Inc.  All rights reserved.       *
+*                                                                              *
+*      Written by Ali Sazegari, started on June 1991.                          *
+*                                                                              *
+*      August    26 1991: no CFront Version 1.1d17 warnings.                   *
+*      September 06 1991: passes the test suite with invalid raised on         *
+*                         signaling nans.  sane rom code behaves the same.     *
+*      September 24 1992: took the ̉#include support.hÓ out.                   *
+*      Dcember   02 1992: PowerPC port.                                        *
+*      July      20 1994: __fabs added                                         *
+*      July      21 1994: deleted unnecessary functions: neg, COPYSIGNnew,     *
+*                         and SIGNNUMnew.                                      *
+*	 April     11 2001: first port to os x using gcc.				 *
+*				  removed fabs and deffered to gcc for direct          *
+*				  instruction generation.					 *
+*                                                                              *
+*******************************************************************************/
+
+#include "fp_private.h"
+
+/*******************************************************************************
+*                                                                              *
+*     Function copysign.                                                       *
+*     Implementation of copysign for the PowerPC.                              *
+*                                                                              *
+********************************************************************************
+*     Note: The order of the operands in this function is reversed from that   *
+*     suggested in the IEEE standard 754.                                      *
+*******************************************************************************/
+
+double copysign ( double arg2, double arg1 )
+      {
+      union
+            {
+            dHexParts hex;
+            double dbl;
+            } x, y;
+
+/*******************************************************************************
+*     No need to flush NaNs out.                                               *
+*******************************************************************************/
+      
+      x.dbl = arg1;
+      y.dbl = arg2;
+      
+      y.hex.high = y.hex.high & 0x7FFFFFFF;
+      y.hex.high = ( y.hex.high | ( x.hex.high & dSgnMask ) );
+      
+      return y.dbl;
+      }