| /* |
| 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; |
| } |
| |
| int8 SetRoundingMode(const unsigned int opcode) |
| { |
| switch (opcode & MASK_ROUNDING_MODE) { |
| default: |
| case ROUND_TO_NEAREST: |
| return float_round_nearest_even; |
| |
| case ROUND_TO_PLUS_INFINITY: |
| return float_round_up; |
| |
| case ROUND_TO_MINUS_INFINITY: |
| return float_round_down; |
| |
| case ROUND_TO_ZERO: |
| return float_round_to_zero; |
| } |
| } |
| |
| int8 SetRoundingPrecision(const unsigned int opcode) |
| { |
| #ifdef CONFIG_FPE_NWFPE_XP |
| switch (opcode & MASK_ROUNDING_PRECISION) { |
| case ROUND_SINGLE: |
| return 32; |
| |
| case ROUND_DOUBLE: |
| return 64; |
| |
| case ROUND_EXTENDED: |
| return 80; |
| |
| default: |
| return 80; |
| } |
| #endif |
| return 80; |
| } |
| |
| 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(); |
| 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; |
| } |