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1 | /*- |
2 | * Copyright (c) 1990 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * William Jolitz. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. All advertising materials mentioning features or use of this software | |
17 | * must display the following acknowledgement: | |
18 | * This product includes software developed by the University of | |
19 | * California, Berkeley and its contributors. | |
20 | * 4. Neither the name of the University nor the names of its contributors | |
21 | * may be used to endorse or promote products derived from this software | |
22 | * without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
35 | * | |
db11a0e0 RG |
36 | * from: @(#)npx.h 5.3 (Berkeley) 1/18/91 |
37 | * $Id$ | |
15637ed4 RG |
38 | */ |
39 | ||
40 | /* | |
41 | * 287/387 NPX Coprocessor Data Structures and Constants | |
42 | * W. Jolitz 1/90 | |
43 | */ | |
44 | ||
45 | #ifndef ___NPX87___ | |
46 | #define ___NPX87___ | |
47 | ||
48 | /* Environment information of floating point unit */ | |
49 | struct env87 { | |
50 | long en_cw; /* control word (16bits) */ | |
51 | long en_sw; /* status word (16bits) */ | |
52 | long en_tw; /* tag word (16bits) */ | |
53 | long en_fip; /* floating point instruction pointer */ | |
54 | u_short en_fcs; /* floating code segment selector */ | |
55 | u_short en_opcode; /* opcode last executed (11 bits ) */ | |
56 | long en_foo; /* floating operand offset */ | |
57 | long en_fos; /* floating operand segment selector */ | |
58 | }; | |
59 | ||
60 | /* Contents of each floating point accumulator */ | |
61 | struct fpacc87 { | |
62 | #ifdef dontdef /* too unportable */ | |
63 | u_long fp_mantlo; /* mantissa low (31:0) */ | |
64 | u_long fp_manthi; /* mantissa high (63:32) */ | |
65 | int fp_exp:15; /* exponent */ | |
66 | int fp_sgn:1; /* mantissa sign */ | |
67 | #else | |
68 | u_char fp_bytes[10]; | |
69 | #endif | |
70 | }; | |
71 | ||
72 | /* Floating point context */ | |
73 | struct save87 { | |
74 | struct env87 sv_env; /* floating point control/status */ | |
75 | struct fpacc87 sv_ac[8]; /* accumulator contents, 0-7 */ | |
76 | #ifndef dontdef | |
77 | u_long sv_ex_sw; /* status word for last exception (was pad) */ | |
78 | u_long sv_ex_tw; /* tag word for last exception (was pad) */ | |
79 | u_char sv_pad[8 * 2 - 2 * 4]; /* bogus historical padding */ | |
80 | #endif | |
81 | }; | |
82 | ||
83 | /* Cyrix EMC memory - mapped coprocessor context switch information */ | |
84 | struct emcsts { | |
85 | long em_msw; /* memory mapped status register when swtched */ | |
86 | long em_tar; /* memory mapped temp A register when swtched */ | |
87 | long em_dl; /* memory mapped D low register when swtched */ | |
88 | }; | |
89 | ||
90 | /* Intel prefers long real (53 bit) precision */ | |
91 | #define __iBCS_NPXCW__ 0x262 | |
92 | /* wfj prefers temporary real (64 bit) precision */ | |
93 | #define __386BSD_NPXCW__ 0x362 | |
94 | /* | |
95 | * bde prefers 53 bit precision and all exceptions masked. | |
96 | * | |
97 | * The standard control word from finit is 0x37F, giving: | |
98 | * | |
99 | * round to nearest | |
100 | * 64-bit precision | |
101 | * all exceptions masked. | |
102 | * | |
103 | * Now I want: | |
104 | * | |
105 | * affine mode for 287's (if they work at all) (1 in bitfield 1<<12) | |
106 | * 53-bit precision (2 in bitfield 3<<8) | |
107 | * overflow exception unmasked (0 in bitfield 1<<3) | |
108 | * zero divide exception unmasked (0 in bitfield 1<<2) | |
109 | * invalid-operand exception unmasked (0 in bitfield 1<<0). | |
110 | * | |
111 | * 64-bit precision often gives bad results with high level languages | |
112 | * because it makes the results of calculations depend on whether | |
113 | * intermediate values are stored in memory or in FPU registers. | |
114 | * | |
115 | * The "Intel" and wfj control words have: | |
116 | * | |
117 | * underflow exception unmasked (0 in bitfield 1<<4) | |
118 | * | |
119 | * but that causes an unexpected exception in the test program 'paranoia' | |
120 | * and makes denormals useless (DBL_MIN / 2 underflows). It doesn't make | |
121 | * a lot of sense to trap underflow without trapping denormals. | |
122 | * | |
123 | * Later I will want the IEEE default of all exceptions masked. See the | |
124 | * 0.0 math manpage for why this is better. The 0.1 math manpage is empty. | |
125 | */ | |
126 | #define __BDE_NPXCW__ 0x1272 | |
127 | #define __BETTER_BDE_NPXCW__ 0x127f | |
128 | ||
129 | #ifdef __BROKEN_NPXCW__ | |
130 | #ifdef __386BSD__ | |
131 | #define __INITIAL_NPXCW__ __386BSD_NPXCW__ | |
132 | #else | |
133 | #define __INITIAL_NPXCW__ __iBCS_NPXCW__ | |
134 | #endif | |
135 | #else | |
136 | #define __INITIAL_NPXCW__ __BDE_NPXCW__ | |
137 | #endif | |
138 | ||
139 | #endif ___NPX87___ |