mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 00:21:59 +00:00
50a23e6eec
The patch below updates broken web addresses in the arch directory. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Randy Dunlap <rdunlap@xenotime.net> Reviewed-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/* IEEE754 floating point arithmetic
|
|
* double precision: common utilities
|
|
*/
|
|
/*
|
|
* MIPS floating point support
|
|
* Copyright (C) 1994-2000 Algorithmics Ltd.
|
|
*
|
|
* ########################################################################
|
|
*
|
|
* 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"
|
|
|
|
s64 ieee754dp_tlong(ieee754dp x)
|
|
{
|
|
COMPXDP;
|
|
|
|
CLEARCX;
|
|
|
|
EXPLODEXDP;
|
|
FLUSHXDP;
|
|
|
|
switch (xc) {
|
|
case IEEE754_CLASS_SNAN:
|
|
case IEEE754_CLASS_QNAN:
|
|
case IEEE754_CLASS_INF:
|
|
SETCX(IEEE754_INVALID_OPERATION);
|
|
return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
|
|
case IEEE754_CLASS_ZERO:
|
|
return 0;
|
|
case IEEE754_CLASS_DNORM:
|
|
case IEEE754_CLASS_NORM:
|
|
break;
|
|
}
|
|
if (xe >= 63) {
|
|
/* look for valid corner case */
|
|
if (xe == 63 && xs && xm == DP_HIDDEN_BIT)
|
|
return -0x8000000000000000LL;
|
|
/* Set invalid. We will only use overflow for floating
|
|
point overflow */
|
|
SETCX(IEEE754_INVALID_OPERATION);
|
|
return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
|
|
}
|
|
/* oh gawd */
|
|
if (xe > DP_MBITS) {
|
|
xm <<= xe - DP_MBITS;
|
|
} else if (xe < DP_MBITS) {
|
|
u64 residue;
|
|
int round;
|
|
int sticky;
|
|
int odd;
|
|
|
|
if (xe < -1) {
|
|
residue = xm;
|
|
round = 0;
|
|
sticky = residue != 0;
|
|
xm = 0;
|
|
} else {
|
|
/* Shifting a u64 64 times does not work,
|
|
* so we do it in two steps. Be aware that xe
|
|
* may be -1 */
|
|
residue = xm << (xe + 1);
|
|
residue <<= 63 - DP_MBITS;
|
|
round = (residue >> 63) != 0;
|
|
sticky = (residue << 1) != 0;
|
|
xm >>= DP_MBITS - xe;
|
|
}
|
|
odd = (xm & 0x1) != 0x0;
|
|
switch (ieee754_csr.rm) {
|
|
case IEEE754_RN:
|
|
if (round && (sticky || odd))
|
|
xm++;
|
|
break;
|
|
case IEEE754_RZ:
|
|
break;
|
|
case IEEE754_RU: /* toward +Infinity */
|
|
if ((round || sticky) && !xs)
|
|
xm++;
|
|
break;
|
|
case IEEE754_RD: /* toward -Infinity */
|
|
if ((round || sticky) && xs)
|
|
xm++;
|
|
break;
|
|
}
|
|
if ((xm >> 63) != 0) {
|
|
/* This can happen after rounding */
|
|
SETCX(IEEE754_INVALID_OPERATION);
|
|
return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
|
|
}
|
|
if (round || sticky)
|
|
SETCX(IEEE754_INEXACT);
|
|
}
|
|
if (xs)
|
|
return -xm;
|
|
else
|
|
return xm;
|
|
}
|
|
|
|
|
|
u64 ieee754dp_tulong(ieee754dp x)
|
|
{
|
|
ieee754dp hb = ieee754dp_1e63();
|
|
|
|
/* what if x < 0 ?? */
|
|
if (ieee754dp_lt(x, hb))
|
|
return (u64) ieee754dp_tlong(x);
|
|
|
|
return (u64) ieee754dp_tlong(ieee754dp_sub(x, hb)) |
|
|
(1ULL << 63);
|
|
}
|