xref: /openbmc/linux/arch/arm/nwfpe/fpsr.h (revision 9cfc5c90)
1 /*
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 /*
26 The FPSR is a 32 bit register consisting of 4 parts, each exactly
27 one byte.
28 
29 	SYSTEM ID
30 	EXCEPTION TRAP ENABLE BYTE
31 	SYSTEM CONTROL BYTE
32 	CUMULATIVE EXCEPTION FLAGS BYTE
33 
34 The FPCR is a 32 bit register consisting of bit flags.
35 */
36 
37 /* SYSTEM ID
38 ------------
39 Note: the system id byte is read only  */
40 
41 typedef unsigned int FPSR;	/* type for floating point status register */
42 typedef 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
109