kernel_optimize_test/arch/mips/math-emu/dp_simple.c
Nigel Stephens cea2be4443 MIPS: Fix abs.[sd] and neg.[sd] emulation for NaN operands
This patch ensures that the sign bit is always updated for NaN operands.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-11-02 12:00:05 +01:00

86 lines
1.8 KiB
C

/* IEEE754 floating point arithmetic
* double precision: common utilities
*/
/*
* MIPS floating point support
* Copyright (C) 1994-2000 Algorithmics Ltd.
* http://www.algor.co.uk
*
* ########################################################################
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* ########################################################################
*/
#include "ieee754dp.h"
int ieee754dp_finite(ieee754dp x)
{
return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
}
ieee754dp ieee754dp_copysign(ieee754dp x, ieee754dp y)
{
CLEARCX;
DPSIGN(x) = DPSIGN(y);
return x;
}
ieee754dp ieee754dp_neg(ieee754dp x)
{
COMPXDP;
EXPLODEXDP;
CLEARCX;
FLUSHXDP;
/*
* Invert the sign ALWAYS to prevent an endless recursion on
* pow() in libc.
*/
/* quick fix up */
DPSIGN(x) ^= 1;
if (xc == IEEE754_CLASS_SNAN) {
ieee754dp y = ieee754dp_indef();
SETCX(IEEE754_INVALID_OPERATION);
DPSIGN(y) = DPSIGN(x);
return ieee754dp_nanxcpt(y, "neg");
}
return x;
}
ieee754dp ieee754dp_abs(ieee754dp x)
{
COMPXDP;
EXPLODEXDP;
CLEARCX;
FLUSHXDP;
/* Clear sign ALWAYS, irrespective of NaN */
DPSIGN(x) = 0;
if (xc == IEEE754_CLASS_SNAN) {
return ieee754dp_nanxcpt(ieee754dp_indef(), "abs");
}
return x;
}