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
29#include <linux/compiler.h>
30#include <linux/string.h>
31
32/* Reset the FPA11 chip.  Called to initialize and reset the emulator. */
33static void resetFPA11(void)
34{
35	int i;
36	FPA11 *fpa11 = GET_FPA11();
37
38	/* initialize the register type array */
39	for (i = 0; i <= 7; i++) {
40		fpa11->fType[i] = typeNone;
41	}
42
43	/* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
44	fpa11->fpsr = FP_EMULATOR | BIT_AC;
45}
46
47int8 SetRoundingMode(const unsigned int opcode)
48{
49	switch (opcode & MASK_ROUNDING_MODE) {
50	default:
51	case ROUND_TO_NEAREST:
52		return float_round_nearest_even;
53
54	case ROUND_TO_PLUS_INFINITY:
55		return float_round_up;
56
57	case ROUND_TO_MINUS_INFINITY:
58		return float_round_down;
59
60	case ROUND_TO_ZERO:
61		return float_round_to_zero;
62	}
63}
64
65int8 SetRoundingPrecision(const unsigned int opcode)
66{
67#ifdef CONFIG_FPE_NWFPE_XP
68	switch (opcode & MASK_ROUNDING_PRECISION) {
69	case ROUND_SINGLE:
70		return 32;
71
72	case ROUND_DOUBLE:
73		return 64;
74
75	case ROUND_EXTENDED:
76		return 80;
77
78	default:
79		return 80;
80	}
81#endif
82	return 80;
83}
84
85void nwfpe_init_fpa(union fp_state *fp)
86{
87	FPA11 *fpa11 = (FPA11 *)fp;
88#ifdef NWFPE_DEBUG
89	printk("NWFPE: setting up state.\n");
90#endif
91 	memset(fpa11, 0, sizeof(FPA11));
92	resetFPA11();
93	fpa11->initflag = 1;
94}
95
96/* Emulate the instruction in the opcode. */
97unsigned int EmulateAll(unsigned int opcode)
98{
99	unsigned int code;
100
101#ifdef NWFPE_DEBUG
102	printk("NWFPE: emulating opcode %08x\n", opcode);
103#endif
104	code = opcode & 0x00000f00;
105	if (code == 0x00000100 || code == 0x00000200) {
106		/* For coprocessor 1 or 2 (FPA11) */
107		code = opcode & 0x0e000000;
108		if (code == 0x0e000000) {
109			if (opcode & 0x00000010) {
110				/* Emulate conversion opcodes. */
111				/* Emulate register transfer opcodes. */
112				/* Emulate comparison opcodes. */
113				return EmulateCPRT(opcode);
114			} else {
115				/* Emulate monadic arithmetic opcodes. */
116				/* Emulate dyadic arithmetic opcodes. */
117				return EmulateCPDO(opcode);
118			}
119		} else if (code == 0x0c000000) {
120			/* Emulate load/store opcodes. */
121			/* Emulate load/store multiple opcodes. */
122			return EmulateCPDT(opcode);
123		}
124	}
125
126	/* Invalid instruction detected.  Return FALSE. */
127	return 0;
128}
129