xref: /openbmc/qemu/linux-user/arm/nwfpe/fpsr.h (revision ffe98631)
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, see <http://www.gnu.org/licenses/>.
19 */
20 
21 #ifndef FPSR_H
22 #define FPSR_H
23 
24 /*
25 The FPSR is a 32 bit register consisting of 4 parts, each exactly
26 one byte.
27 
28 	SYSTEM ID
29 	EXCEPTION TRAP ENABLE BYTE
30 	SYSTEM CONTROL BYTE
31 	CUMULATIVE EXCEPTION FLAGS BYTE
32 
33 The FPCR is a 32 bit register consisting of bit flags.
34 */
35 
36 /* SYSTEM ID
37 ------------
38 Note: the system id byte is read only  */
39 
40 typedef unsigned int FPSR;  /* type for floating point status register */
41 typedef unsigned int FPCR;  /* type for floating point control register */
42 
43 #define MASK_SYSID		0xff000000
44 #define BIT_HARDWARE		0x80000000
45 #define FP_EMULATOR		0x01000000	/* System ID for emulator */
46 #define FP_ACCELERATOR		0x81000000	/* System ID for FPA11 */
47 
48 /* EXCEPTION TRAP ENABLE BYTE
49 ----------------------------- */
50 
51 #define MASK_TRAP_ENABLE	0x00ff0000
52 #define MASK_TRAP_ENABLE_STRICT	0x001f0000
53 #define BIT_IXE		0x00100000   /* inexact exception enable */
54 #define BIT_UFE		0x00080000   /* underflow exception enable */
55 #define BIT_OFE		0x00040000   /* overflow exception enable */
56 #define BIT_DZE		0x00020000   /* divide by zero exception enable */
57 #define BIT_IOE		0x00010000   /* invalid operation exception enable */
58 
59 /* SYSTEM CONTROL BYTE
60 ---------------------- */
61 
62 #define MASK_SYSTEM_CONTROL	0x0000ff00
63 #define MASK_TRAP_STRICT	0x00001f00
64 
65 #define BIT_AC	0x00001000	/* use alternative C-flag definition
66 				   for compares */
67 #define BIT_EP	0x00000800	/* use expanded packed decimal format */
68 #define BIT_SO	0x00000400	/* select synchronous operation of FPA */
69 #define BIT_NE	0x00000200	/* NaN exception bit */
70 #define BIT_ND	0x00000100	/* no denormalized numbers bit */
71 
72 /* CUMULATIVE EXCEPTION FLAGS BYTE
73 ---------------------------------- */
74 
75 #define MASK_EXCEPTION_FLAGS		0x000000ff
76 #define MASK_EXCEPTION_FLAGS_STRICT	0x0000001f
77 
78 #define BIT_IXC		0x00000010	/* inexact exception flag */
79 #define BIT_UFC		0x00000008	/* underflow exception flag */
80 #define BIT_OFC		0x00000004	/* overfloat exception flag */
81 #define BIT_DZC		0x00000002	/* divide by zero exception flag */
82 #define BIT_IOC		0x00000001	/* invalid operation exception flag */
83 
84 /* Floating Point Control Register
85 ----------------------------------*/
86 
87 #define BIT_RU		0x80000000	/* rounded up bit */
88 #define BIT_IE		0x10000000	/* inexact bit */
89 #define BIT_MO		0x08000000	/* mantissa overflow bit */
90 #define BIT_EO		0x04000000	/* exponent overflow bit */
91 #define BIT_SB		0x00000800	/* store bounce */
92 #define BIT_AB		0x00000400	/* arithmetic bounce */
93 #define BIT_RE		0x00000200	/* rounding exception */
94 #define BIT_DA		0x00000100	/* disable FPA */
95 
96 #define MASK_OP		0x00f08010	/* AU operation code */
97 #define MASK_PR		0x00080080	/* AU precision */
98 #define MASK_S1		0x00070000	/* AU source register 1 */
99 #define MASK_S2		0x00000007	/* AU source register 2 */
100 #define MASK_DS		0x00007000	/* AU destination register */
101 #define MASK_RM		0x00000060	/* AU rounding mode */
102 #define MASK_ALU	0x9cfff2ff	/* only ALU can write these bits */
103 #define MASK_RESET	0x00000d00	/* bits set on reset, all others cleared */
104 #define MASK_WFC	MASK_RESET
105 #define MASK_RFC	~MASK_RESET
106 
107 #endif
108