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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/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;
}
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