PATCH RFA: Fix simulator handling of floating point absolute value

[Ian Lance Taylor <ian@airs.com>]

The common simulator routine sim_fpu_abs is used by MIPS, MN10300,
SH64, and perhaps some CGEN generated simulators (it is called by
cgen-accfp.c).  On most, and perhaps all, hardware, a floating point
absolute value instruction simply clears the sign bit.  However,
sim_fpu_abs does not clear the sign bit when given a NaN.  For MIPS,
this causes the gcc test gcc.c-torture/execute/ieee/copysign1.c to
fail.

This patch changes sim_fpu_abs to always clear the sign bit of the
argument.  It does not otherwise change the behaviour.  This, plus
another patch I am about to sign, fixes the gcc copysign1 test for
MIPS.

OK for mainline?

Ian


2005-07-07  Ian Lance Taylor  <ian@airs.com>

	* sim-fpu.c (sim_fpu_abs): Always clear the sign bit.


Index: common/sim-fpu.c
===================================================================
RCS file: /cvs/src/src/sim/common/sim-fpu.c,v
retrieving revision 1.8
diff -p -u -r1.8 sim-fpu.c
--- common/sim-fpu.c	22 Jun 2003 13:36:26 -0000	1.8
+++ common/sim-fpu.c	8 Jul 2005 05:05:12 -0000
@@ -1733,19 +1744,13 @@ INLINE_SIM_FPU (int)
 sim_fpu_abs (sim_fpu *f,
 	     const sim_fpu *r)
 {
+  *f = *r;
+  f->sign = 0;
   if (sim_fpu_is_snan (r))
     {
-      *f = *r;
       f->class = sim_fpu_class_qnan;
       return sim_fpu_status_invalid_snan;
     }
-  if (sim_fpu_is_qnan (r))
-    {
-      *f = *r;
-      return 0;
-    }
-  *f = *r;
-  f->sign = 0;
   return 0;
 }