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- /*
- NetWinder Floating Point Emulator
- (c) Rebel.COM, 1998,1999
- (c) Philip Blundell, 1999, 2001
- 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"
- #include "fpa11.inl"
- #include "fpmodule.h"
- #include "fpmodule.inl"
- #include "softfloat.h"
- unsigned int PerformFLT(const unsigned int opcode);
- unsigned int PerformFIX(const unsigned int opcode);
- static unsigned int PerformComparison(const unsigned int opcode);
- unsigned int EmulateCPRT(const unsigned int opcode)
- {
- if (opcode & 0x800000) {
- /* This is some variant of a comparison (PerformComparison
- will sort out which one). Since most of the other CPRT
- instructions are oddball cases of some sort or other it
- makes sense to pull this out into a fast path. */
- return PerformComparison(opcode);
- }
- /* Hint to GCC that we'd like a jump table rather than a load of CMPs */
- switch ((opcode & 0x700000) >> 20) {
- case FLT_CODE >> 20:
- return PerformFLT(opcode);
- break;
- case FIX_CODE >> 20:
- return PerformFIX(opcode);
- break;
- case WFS_CODE >> 20:
- writeFPSR(readRegister(getRd(opcode)));
- break;
- case RFS_CODE >> 20:
- writeRegister(getRd(opcode), readFPSR());
- break;
- default:
- return 0;
- }
- return 1;
- }
- unsigned int PerformFLT(const unsigned int opcode)
- {
- FPA11 *fpa11 = GET_FPA11();
- struct roundingData roundData;
- roundData.mode = SetRoundingMode(opcode);
- roundData.precision = SetRoundingPrecision(opcode);
- roundData.exception = 0;
- switch (opcode & MASK_ROUNDING_PRECISION) {
- case ROUND_SINGLE:
- {
- fpa11->fType[getFn(opcode)] = typeSingle;
- fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(&roundData, readRegister(getRd(opcode)));
- }
- break;
- case ROUND_DOUBLE:
- {
- fpa11->fType[getFn(opcode)] = typeDouble;
- fpa11->fpreg[getFn(opcode)].fDouble = int32_to_float64(readRegister(getRd(opcode)));
- }
- break;
- #ifdef CONFIG_FPE_NWFPE_XP
- case ROUND_EXTENDED:
- {
- fpa11->fType[getFn(opcode)] = typeExtended;
- fpa11->fpreg[getFn(opcode)].fExtended = int32_to_floatx80(readRegister(getRd(opcode)));
- }
- break;
- #endif
- default:
- return 0;
- }
- if (roundData.exception)
- float_raise(roundData.exception);
- return 1;
- }
- unsigned int PerformFIX(const unsigned int opcode)
- {
- FPA11 *fpa11 = GET_FPA11();
- unsigned int Fn = getFm(opcode);
- struct roundingData roundData;
- roundData.mode = SetRoundingMode(opcode);
- roundData.precision = SetRoundingPrecision(opcode);
- roundData.exception = 0;
- switch (fpa11->fType[Fn]) {
- case typeSingle:
- {
- writeRegister(getRd(opcode), float32_to_int32(&roundData, fpa11->fpreg[Fn].fSingle));
- }
- break;
- case typeDouble:
- {
- writeRegister(getRd(opcode), float64_to_int32(&roundData, fpa11->fpreg[Fn].fDouble));
- }
- break;
- #ifdef CONFIG_FPE_NWFPE_XP
- case typeExtended:
- {
- writeRegister(getRd(opcode), floatx80_to_int32(&roundData, fpa11->fpreg[Fn].fExtended));
- }
- break;
- #endif
- default:
- return 0;
- }
- if (roundData.exception)
- float_raise(roundData.exception);
- return 1;
- }
- /* This instruction sets the flags N, Z, C, V in the FPSR. */
- static unsigned int PerformComparison(const unsigned int opcode)
- {
- FPA11 *fpa11 = GET_FPA11();
- unsigned int Fn = getFn(opcode), Fm = getFm(opcode);
- int e_flag = opcode & 0x400000; /* 1 if CxFE */
- int n_flag = opcode & 0x200000; /* 1 if CNxx */
- unsigned int flags = 0;
- #ifdef CONFIG_FPE_NWFPE_XP
- floatx80 rFn, rFm;
- /* Check for unordered condition and convert all operands to 80-bit
- format.
- ?? Might be some mileage in avoiding this conversion if possible.
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