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Diffstat (limited to 'arch/arm/nwfpe/fpa11.c')
-rw-r--r-- | arch/arm/nwfpe/fpa11.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/arm/nwfpe/fpa11.c b/arch/arm/nwfpe/fpa11.c new file mode 100644 index 000000000000..bf61696865ec --- /dev/null +++ b/arch/arm/nwfpe/fpa11.c @@ -0,0 +1,143 @@ +/* + NetWinder Floating Point Emulator + (c) Rebel.COM, 1998,1999 + (c) Philip Blundell, 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 "fpmodule.h" +#include "fpmodule.inl" + +#include <linux/config.h> +#include <linux/compiler.h> +#include <linux/string.h> +#include <asm/system.h> + +/* forward declarations */ +unsigned int EmulateCPDO(const unsigned int); +unsigned int EmulateCPDT(const unsigned int); +unsigned int EmulateCPRT(const unsigned int); + +/* Reset the FPA11 chip. Called to initialize and reset the emulator. */ +static void resetFPA11(void) +{ + int i; + FPA11 *fpa11 = GET_FPA11(); + + /* initialize the register type array */ + for (i = 0; i <= 7; i++) { + fpa11->fType[i] = typeNone; + } + + /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */ + fpa11->fpsr = FP_EMULATOR | BIT_AC; +} + +void SetRoundingMode(const unsigned int opcode) +{ + switch (opcode & MASK_ROUNDING_MODE) { + default: + case ROUND_TO_NEAREST: + float_rounding_mode = float_round_nearest_even; + break; + + case ROUND_TO_PLUS_INFINITY: + float_rounding_mode = float_round_up; + break; + + case ROUND_TO_MINUS_INFINITY: + float_rounding_mode = float_round_down; + break; + + case ROUND_TO_ZERO: + float_rounding_mode = float_round_to_zero; + break; + } +} + +void SetRoundingPrecision(const unsigned int opcode) +{ +#ifdef CONFIG_FPE_NWFPE_XP + switch (opcode & MASK_ROUNDING_PRECISION) { + case ROUND_SINGLE: + floatx80_rounding_precision = 32; + break; + + case ROUND_DOUBLE: + floatx80_rounding_precision = 64; + break; + + case ROUND_EXTENDED: + floatx80_rounding_precision = 80; + break; + + default: + floatx80_rounding_precision = 80; + } +#endif +} + +void nwfpe_init_fpa(union fp_state *fp) +{ + FPA11 *fpa11 = (FPA11 *)fp; +#ifdef NWFPE_DEBUG + printk("NWFPE: setting up state.\n"); +#endif + memset(fpa11, 0, sizeof(FPA11)); + resetFPA11(); + SetRoundingMode(ROUND_TO_NEAREST); + SetRoundingPrecision(ROUND_EXTENDED); + fpa11->initflag = 1; +} + +/* Emulate the instruction in the opcode. */ +unsigned int EmulateAll(unsigned int opcode) +{ + unsigned int code; + +#ifdef NWFPE_DEBUG + printk("NWFPE: emulating opcode %08x\n", opcode); +#endif + code = opcode & 0x00000f00; + if (code == 0x00000100 || code == 0x00000200) { + /* For coprocessor 1 or 2 (FPA11) */ + code = opcode & 0x0e000000; + if (code == 0x0e000000) { + if (opcode & 0x00000010) { + /* Emulate conversion opcodes. */ + /* Emulate register transfer opcodes. */ + /* Emulate comparison opcodes. */ + return EmulateCPRT(opcode); + } else { + /* Emulate monadic arithmetic opcodes. */ + /* Emulate dyadic arithmetic opcodes. */ + return EmulateCPDO(opcode); + } + } else if (code == 0x0c000000) { + /* Emulate load/store opcodes. */ + /* Emulate load/store multiple opcodes. */ + return EmulateCPDT(opcode); + } + } + + /* Invalid instruction detected. Return FALSE. */ + return 0; +} |