118 строки
3.5 KiB
C
118 строки
3.5 KiB
C
|
/*
|
||
|
|
NetWinder Floating Point Emulator
|
||
|
|
(c) Rebel.COM, 1998,1999
|
||
|
|
|
||
|
|
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
|
||
|
|
|
||
|
|
This program is free software; you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation; either version 2 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
This program is distributed in the hope that 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "fpa11.h"
|
||
|
|
#include "fpopcode.h"
|
||
|
|
|
||
|
|
unsigned int SingleCPDO(const unsigned int opcode);
|
||
|
|
unsigned int DoubleCPDO(const unsigned int opcode);
|
||
|
|
unsigned int ExtendedCPDO(const unsigned int opcode);
|
||
|
|
|
||
|
|
unsigned int EmulateCPDO(const unsigned int opcode)
|
||
|
|
{
|
||
|
|
FPA11 *fpa11 = GET_FPA11();
|
||
|
|
unsigned int Fd, nType, nDest, nRc = 1;
|
||
|
|
|
||
|
|
//printk("EmulateCPDO(0x%08x)\n",opcode);
|
||
|
|
|
||
|
|
/* Get the destination size. If not valid let Linux perform
|
||
|
|
an invalid instruction trap. */
|
||
|
|
nDest = getDestinationSize(opcode);
|
||
|
|
if (typeNone == nDest) return 0;
|
||
|
|
|
||
|
|
SetRoundingMode(opcode);
|
||
|
|
|
||
|
|
/* Compare the size of the operands in Fn and Fm.
|
||
|
|
Choose the largest size and perform operations in that size,
|
||
|
|
in order to make use of all the precision of the operands.
|
||
|
|
If Fm is a constant, we just grab a constant of a size
|
||
|
|
matching the size of the operand in Fn. */
|
||
|
|
if (MONADIC_INSTRUCTION(opcode))
|
||
|
|
nType = nDest;
|
||
|
|
else
|
||
|
|
nType = fpa11->fType[getFn(opcode)];
|
||
|
|
|
||
|
|
if (!CONSTANT_FM(opcode))
|
||
|
|
{
|
||
|
|
register unsigned int Fm = getFm(opcode);
|
||
|
|
if (nType < fpa11->fType[Fm])
|
||
|
|
{
|
||
|
|
nType = fpa11->fType[Fm];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
switch (nType)
|
||
|
|
{
|
||
|
|
case typeSingle : nRc = SingleCPDO(opcode); break;
|
||
|
|
case typeDouble : nRc = DoubleCPDO(opcode); break;
|
||
|
|
case typeExtended : nRc = ExtendedCPDO(opcode); break;
|
||
|
|
default : nRc = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* If the operation succeeded, check to see if the result in the
|
||
|
|
destination register is the correct size. If not force it
|
||
|
|
to be. */
|
||
|
|
Fd = getFd(opcode);
|
||
|
|
nType = fpa11->fType[Fd];
|
||
|
|
if ((0 != nRc) && (nDest != nType))
|
||
|
|
{
|
||
|
|
switch (nDest)
|
||
|
|
{
|
||
|
|
case typeSingle:
|
||
|
|
{
|
||
|
|
if (typeDouble == nType)
|
||
|
|
fpa11->fpreg[Fd].fSingle =
|
||
|
|
float64_to_float32(fpa11->fpreg[Fd].fDouble);
|
||
|
|
else
|
||
|
|
fpa11->fpreg[Fd].fSingle =
|
||
|
|
floatx80_to_float32(fpa11->fpreg[Fd].fExtended);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case typeDouble:
|
||
|
|
{
|
||
|
|
if (typeSingle == nType)
|
||
|
|
fpa11->fpreg[Fd].fDouble =
|
||
|
|
float32_to_float64(fpa11->fpreg[Fd].fSingle);
|
||
|
|
else
|
||
|
|
fpa11->fpreg[Fd].fDouble =
|
||
|
|
floatx80_to_float64(fpa11->fpreg[Fd].fExtended);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case typeExtended:
|
||
|
|
{
|
||
|
|
if (typeSingle == nType)
|
||
|
|
fpa11->fpreg[Fd].fExtended =
|
||
|
|
float32_to_floatx80(fpa11->fpreg[Fd].fSingle);
|
||
|
|
else
|
||
|
|
fpa11->fpreg[Fd].fExtended =
|
||
|
|
float64_to_floatx80(fpa11->fpreg[Fd].fDouble);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
fpa11->fType[Fd] = nDest;
|
||
|
|
}
|
||
|
|
|
||
|
|
return nRc;
|
||
|
|
}
|