diff options
Diffstat (limited to 'arch/arm/nwfpe/fpa11.c')
| -rw-r--r-- | arch/arm/nwfpe/fpa11.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/arch/arm/nwfpe/fpa11.c b/arch/arm/nwfpe/fpa11.c new file mode 100644 index 000000000..506821ca8 --- /dev/null +++ b/arch/arm/nwfpe/fpa11.c @@ -0,0 +1,206 @@ +/* + NetWinder Floating Point Emulator + (c) Corel Computer Corporation, 1998 + + Direct questions, comments to Scott Bambrough <scottb@corelcomputer.com> + + 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 "config.h" +#include "fpa11.h" +#include "milieu.h" +#include "fpopcode.h" + +#include "fpmodule.h" +#include "fpmodule.inl" + +/* forward declarations */ +unsigned int EmulateCPDO(const unsigned int); +unsigned int EmulateCPDT(const unsigned int); +unsigned int EmulateCPRT(const unsigned int); + +/* Emulator registers */ +FPA11 *fpa11; + +/* Reset the FPA11 chip. Called to initialize and reset the emulator. */ +void resetFPA11(void) +{ + int i; + /* initialize the registers */ + for (i=0;i<=7;i++) + { + fpa11->fpreg[i].fType = typeNone; + } + + /* FPSR: set system id to FP_EMULATOR, clear all other bits */ + fpa11->fpsr = FP_EMULATOR; + + /* FPCR: set SB, AB and DA bits, clear all others */ +#if MAINTAIN_FPCR + fpa11->fpcr = MASK_RESET; +#endif +} + +void SetRoundingMode(const unsigned int opcode) +{ +#if MAINTAIN_FPCR + fpa11->fpcr &= ~MASK_ROUNDING_MODE; +#endif + switch (opcode & MASK_ROUNDING_MODE) + { + default: + case ROUND_TO_NEAREST: + float_rounding_mode = float_round_nearest_even; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_TO_NEAREST; +#endif + break; + + case ROUND_TO_PLUS_INFINITY: + float_rounding_mode = float_round_up; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_TO_PLUS_INFINITY; +#endif + break; + + case ROUND_TO_MINUS_INFINITY: + float_rounding_mode = float_round_down; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_TO_MINUS_INFINITY; +#endif + break; + + case ROUND_TO_ZERO: + float_rounding_mode = float_round_to_zero; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_TO_ZERO; +#endif + break; + } +} + +void SetRoundingPrecision(const unsigned int opcode) +{ +#if MAINTAIN_FPCR + fpa11->fpcr &= ~MASK_ROUNDING_PRECISION; +#endif + switch (opcode & MASK_ROUNDING_PRECISION) + { + case ROUND_SINGLE: + floatx80_rounding_precision = 32; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_SINGLE; +#endif + break; + + case ROUND_DOUBLE: + floatx80_rounding_precision = 64; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_DOUBLE; +#endif + break; + + case ROUND_EXTENDED: + floatx80_rounding_precision = 80; +#if MAINTAIN_FPCR + fpa11->fpcr |= ROUND_EXTENDED; +#endif + break; + + default: floatx80_rounding_precision = 80; + } +} + +/* Emulate the instruction in the opcode. */ +unsigned int EmulateAll(unsigned int opcode) +{ + unsigned int nRc = 0; + + if (fpa11->initflag == 0) /* good place for __builtin_expect */ + { + resetFPA11(); + SetRoundingMode(ROUND_TO_NEAREST); + SetRoundingPrecision(ROUND_EXTENDED); + fpa11->initflag = 1; + } + + if (TEST_OPCODE(opcode,MASK_CPRT)) + { + /* Emulate conversion opcodes. */ + /* Emulate register transfer opcodes. */ + /* Emulate comparison opcodes. */ + nRc = EmulateCPRT(opcode); + } + else if (TEST_OPCODE(opcode,MASK_CPDO)) + { + /* Emulate monadic arithmetic opcodes. */ + /* Emulate dyadic arithmetic opcodes. */ + nRc = EmulateCPDO(opcode); + } + else if (TEST_OPCODE(opcode,MASK_CPDT)) + { + /* Emulate load/store opcodes. */ + /* Emulate load/store multiple opcodes. */ + nRc = EmulateCPDT(opcode); + } + else + { + /* Invalid instruction detected. Return FALSE. */ + nRc = 0; + } + + return(nRc); +} + +#if 0 +unsigned int EmulateAll1(unsigned int opcode) +{ + switch ((opcode >> 24) & 0xf) + { + case 0xc: + case 0xd: + if ((opcode >> 20) & 0x1) + { + switch ((opcode >> 8) & 0xf) + { + case 0x1: return PerformLDF(opcode); break; + case 0x2: return PerformLFM(opcode); break; + default: return 0; + } + } + else + { + switch ((opcode >> 8) & 0xf) + { + case 0x1: return PerformSTF(opcode); break; + case 0x2: return PerformSFM(opcode); break; + default: return 0; + } + } + break; + + case 0xe: + if (opcode & 0x10) + return EmulateCPDO(opcode); + else + return EmulateCPRT(opcode); + break; + + default: return 0; + } +} +#endif + |