[deliverable/linux.git] / arch / arm / nwfpe / fpa11.c

/*
    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;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	NetWinder Floating Point Emulator
	3	(c) Rebel.COM, 1998,1999
	4	(c) Philip Blundell, 2001
	5
	6	Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
	7
	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 2 of the License, or
	11	(at your option) any later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program; if not, write to the Free Software
	20	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	21	*/
	22
	23	#include "fpa11.h"
	24	#include "fpopcode.h"
	25
	26	#include "fpmodule.h"
	27	#include "fpmodule.inl"
	28
1da177e4 LT	29	#include <linux/compiler.h>
	30	#include <linux/string.h>
	31	#include <asm/system.h>
	32
1da177e4 LT	33	/* Reset the FPA11 chip. Called to initialize and reset the emulator. */
	34	static void resetFPA11(void)
	35	{
	36	int i;
	37	FPA11 *fpa11 = GET_FPA11();
	38
	39	/* initialize the register type array */
	40	for (i = 0; i <= 7; i++) {
	41	fpa11->fType[i] = typeNone;
	42	}
	43
	44	/* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
	45	fpa11->fpsr = FP_EMULATOR \| BIT_AC;
	46	}
	47
f148af25	48	int8 SetRoundingMode(const unsigned int opcode)
1da177e4 LT	49	{
	50	switch (opcode & MASK_ROUNDING_MODE) {
	51	default:
	52	case ROUND_TO_NEAREST:
f148af25	53	return float_round_nearest_even;
1da177e4 LT	54
1da177e4 LT	55	case ROUND_TO_PLUS_INFINITY:
f148af25	56	return float_round_up;
1da177e4 LT	57
1da177e4 LT	58	case ROUND_TO_MINUS_INFINITY:
f148af25	59	return float_round_down;
1da177e4 LT	60
1da177e4 LT	61	case ROUND_TO_ZERO:
f148af25	62	return float_round_to_zero;
1da177e4 LT	63	}
	64	}
	65
f148af25	66	int8 SetRoundingPrecision(const unsigned int opcode)
1da177e4 LT	67	{
	68	#ifdef CONFIG_FPE_NWFPE_XP
	69	switch (opcode & MASK_ROUNDING_PRECISION) {
	70	case ROUND_SINGLE:
f148af25	71	return 32;
1da177e4 LT	72
1da177e4 LT	73	case ROUND_DOUBLE:
f148af25	74	return 64;
1da177e4 LT	75
1da177e4 LT	76	case ROUND_EXTENDED:
f148af25	77	return 80;
1da177e4 LT	78
1da177e4 LT	79	default:
f148af25	80	return 80;
1da177e4 LT	81	}
1da177e4 LT	82	#endif
f148af25	83	return 80;
1da177e4 LT	84	}
	85
	86	void nwfpe_init_fpa(union fp_state *fp)
	87	{
	88	FPA11 fpa11 = (FPA11 )fp;
	89	#ifdef NWFPE_DEBUG
	90	printk("NWFPE: setting up state.\n");
	91	#endif
	92	memset(fpa11, 0, sizeof(FPA11));
	93	resetFPA11();
1da177e4 LT	94	fpa11->initflag = 1;
	95	}
	96
	97	/* Emulate the instruction in the opcode. */
	98	unsigned int EmulateAll(unsigned int opcode)
	99	{
	100	unsigned int code;
	101
	102	#ifdef NWFPE_DEBUG
	103	printk("NWFPE: emulating opcode %08x\n", opcode);
	104	#endif
	105	code = opcode & 0x00000f00;
	106	if (code == 0x00000100 \|\| code == 0x00000200) {
	107	/* For coprocessor 1 or 2 (FPA11) */
	108	code = opcode & 0x0e000000;
	109	if (code == 0x0e000000) {
	110	if (opcode & 0x00000010) {
	111	/* Emulate conversion opcodes. */
	112	/* Emulate register transfer opcodes. */
	113	/* Emulate comparison opcodes. */
	114	return EmulateCPRT(opcode);
	115	} else {
	116	/* Emulate monadic arithmetic opcodes. */
	117	/* Emulate dyadic arithmetic opcodes. */
	118	return EmulateCPDO(opcode);
	119	}
	120	} else if (code == 0x0c000000) {
	121	/* Emulate load/store opcodes. */
	122	/* Emulate load/store multiple opcodes. */
	123	return EmulateCPDT(opcode);
	124	}
	125	}
	126
	127	/* Invalid instruction detected. Return FALSE. */
	128	return 0;
	129	}