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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 NetWinder Floating Point Emulator
3 (c) Rebel.com, 1998-1999
4
5 Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20*/
21
22#ifndef __FPSR_H__
23#define __FPSR_H__
24
25/*
26The FPSR is a 32 bit register consisting of 4 parts, each exactly
27one byte.
28
29 SYSTEM ID
30 EXCEPTION TRAP ENABLE BYTE
31 SYSTEM CONTROL BYTE
32 CUMULATIVE EXCEPTION FLAGS BYTE
33
34The FPCR is a 32 bit register consisting of bit flags.
35*/
36
37/* SYSTEM ID
38------------
39Note: the system id byte is read only */
40
41typedef unsigned int FPSR; /* type for floating point status register */
42typedef unsigned int FPCR; /* type for floating point control register */
43
44#define MASK_SYSID 0xff000000
45#define BIT_HARDWARE 0x80000000
46#define FP_EMULATOR 0x01000000 /* System ID for emulator */
47#define FP_ACCELERATOR 0x81000000 /* System ID for FPA11 */
48
49/* EXCEPTION TRAP ENABLE BYTE
50----------------------------- */
51
52#define MASK_TRAP_ENABLE 0x00ff0000
53#define MASK_TRAP_ENABLE_STRICT 0x001f0000
54#define BIT_IXE 0x00100000 /* inexact exception enable */
55#define BIT_UFE 0x00080000 /* underflow exception enable */
56#define BIT_OFE 0x00040000 /* overflow exception enable */
57#define BIT_DZE 0x00020000 /* divide by zero exception enable */
58#define BIT_IOE 0x00010000 /* invalid operation exception enable */
59
60/* SYSTEM CONTROL BYTE
61---------------------- */
62
63#define MASK_SYSTEM_CONTROL 0x0000ff00
64#define MASK_TRAP_STRICT 0x00001f00
65
66#define BIT_AC 0x00001000 /* use alternative C-flag definition
67 for compares */
68#define BIT_EP 0x00000800 /* use expanded packed decimal format */
69#define BIT_SO 0x00000400 /* select synchronous operation of FPA */
70#define BIT_NE 0x00000200 /* NaN exception bit */
71#define BIT_ND 0x00000100 /* no denormalized numbers bit */
72
73/* CUMULATIVE EXCEPTION FLAGS BYTE
74---------------------------------- */
75
76#define MASK_EXCEPTION_FLAGS 0x000000ff
77#define MASK_EXCEPTION_FLAGS_STRICT 0x0000001f
78
79#define BIT_IXC 0x00000010 /* inexact exception flag */
80#define BIT_UFC 0x00000008 /* underflow exception flag */
81#define BIT_OFC 0x00000004 /* overfloat exception flag */
82#define BIT_DZC 0x00000002 /* divide by zero exception flag */
83#define BIT_IOC 0x00000001 /* invalid operation exception flag */
84
85/* Floating Point Control Register
86----------------------------------*/
87
88#define BIT_RU 0x80000000 /* rounded up bit */
89#define BIT_IE 0x10000000 /* inexact bit */
90#define BIT_MO 0x08000000 /* mantissa overflow bit */
91#define BIT_EO 0x04000000 /* exponent overflow bit */
92#define BIT_SB 0x00000800 /* store bounce */
93#define BIT_AB 0x00000400 /* arithmetic bounce */
94#define BIT_RE 0x00000200 /* rounding exception */
95#define BIT_DA 0x00000100 /* disable FPA */
96
97#define MASK_OP 0x00f08010 /* AU operation code */
98#define MASK_PR 0x00080080 /* AU precision */
99#define MASK_S1 0x00070000 /* AU source register 1 */
100#define MASK_S2 0x00000007 /* AU source register 2 */
101#define MASK_DS 0x00007000 /* AU destination register */
102#define MASK_RM 0x00000060 /* AU rounding mode */
103#define MASK_ALU 0x9cfff2ff /* only ALU can write these bits */
104#define MASK_RESET 0x00000d00 /* bits set on reset, all others cleared */
105#define MASK_WFC MASK_RESET
106#define MASK_RFC ~MASK_RESET
107
108#endif