139 lines
3.8 KiB
C
139 lines
3.8 KiB
C
/*
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NetWinder Floating Point Emulator
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(c) Rebel.COM, 1998,1999
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(c) Philip Blundell, 2001
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Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/config.h>
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#include "fpa11.h"
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#include "fpopcode.h"
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unsigned int SingleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
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unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
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unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
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unsigned int EmulateCPDO(const unsigned int opcode)
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{
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FPA11 *fpa11 = GET_FPA11();
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FPREG *rFd;
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unsigned int nType, nDest, nRc;
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struct roundingData roundData;
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/* Get the destination size. If not valid let Linux perform
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an invalid instruction trap. */
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nDest = getDestinationSize(opcode);
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if (typeNone == nDest)
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return 0;
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roundData.mode = SetRoundingMode(opcode);
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roundData.precision = SetRoundingPrecision(opcode);
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roundData.exception = 0;
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/* Compare the size of the operands in Fn and Fm.
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Choose the largest size and perform operations in that size,
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in order to make use of all the precision of the operands.
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If Fm is a constant, we just grab a constant of a size
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matching the size of the operand in Fn. */
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if (MONADIC_INSTRUCTION(opcode))
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nType = nDest;
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else
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nType = fpa11->fType[getFn(opcode)];
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if (!CONSTANT_FM(opcode)) {
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register unsigned int Fm = getFm(opcode);
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if (nType < fpa11->fType[Fm]) {
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nType = fpa11->fType[Fm];
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}
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}
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rFd = &fpa11->fpreg[getFd(opcode)];
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switch (nType) {
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case typeSingle:
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nRc = SingleCPDO(&roundData, opcode, rFd);
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break;
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case typeDouble:
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nRc = DoubleCPDO(&roundData, opcode, rFd);
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break;
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#ifdef CONFIG_FPE_NWFPE_XP
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case typeExtended:
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nRc = ExtendedCPDO(&roundData, opcode, rFd);
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break;
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#endif
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default:
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nRc = 0;
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}
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/* The CPDO functions used to always set the destination type
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to be the same as their working size. */
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if (nRc != 0) {
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/* If the operation succeeded, check to see if the result in the
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destination register is the correct size. If not force it
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to be. */
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fpa11->fType[getFd(opcode)] = nDest;
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#ifdef CONFIG_FPE_NWFPE_XP
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if (nDest != nType) {
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switch (nDest) {
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case typeSingle:
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{
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if (typeDouble == nType)
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rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
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else
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rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended);
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}
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break;
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case typeDouble:
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{
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if (typeSingle == nType)
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rFd->fDouble = float32_to_float64(rFd->fSingle);
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else
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rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended);
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}
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break;
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case typeExtended:
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{
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if (typeSingle == nType)
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rFd->fExtended = float32_to_floatx80(rFd->fSingle);
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else
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rFd->fExtended = float64_to_floatx80(rFd->fDouble);
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}
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break;
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}
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}
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#else
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if (nDest != nType) {
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if (nDest == typeSingle)
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rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
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else
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rFd->fDouble = float32_to_float64(rFd->fSingle);
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}
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#endif
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}
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if (roundData.exception)
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float_raise(roundData.exception);
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return nRc;
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}
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