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- /*
- 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/compiler.h>
- #include <linux/string.h>
- #include <asm/system.h>
- /* 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;
- }
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