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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /*---------------------------------------------------------------------------+ |
3 | | fpu_emu.h | | |
4 | | | | |
5 | | Copyright (C) 1992,1993,1994,1997 | | |
6 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | | |
7 | | Australia. E-mail billm@suburbia.net | | |
8 | | | | |
9 | +---------------------------------------------------------------------------*/ | |
10 | ||
1da177e4 LT |
11 | #ifndef _FPU_EMU_H_ |
12 | #define _FPU_EMU_H_ | |
13 | ||
14 | /* | |
15 | * Define PECULIAR_486 to get a closer approximation to 80486 behaviour, | |
16 | * rather than behaviour which appears to be cleaner. | |
17 | * This is a matter of opinion: for all I know, the 80486 may simply | |
18 | * be complying with the IEEE spec. Maybe one day I'll get to see the | |
19 | * spec... | |
20 | */ | |
21 | #define PECULIAR_486 | |
22 | ||
23 | #ifdef __ASSEMBLY__ | |
24 | #include "fpu_asm.h" | |
25 | #define Const(x) $##x | |
26 | #else | |
27 | #define Const(x) x | |
28 | #endif | |
29 | ||
30 | #define EXP_BIAS Const(0) | |
3d0d14f9 IM |
31 | #define EXP_OVER Const(0x4000) /* smallest invalid large exponent */ |
32 | #define EXP_UNDER Const(-0x3fff) /* largest invalid small exponent */ | |
33 | #define EXP_WAY_UNDER Const(-0x6000) /* Below the smallest denormal, but | |
34 | still a 16 bit nr. */ | |
1da177e4 LT |
35 | #define EXP_Infinity EXP_OVER |
36 | #define EXP_NaN EXP_OVER | |
37 | ||
38 | #define EXTENDED_Ebias Const(0x3fff) | |
3d0d14f9 | 39 | #define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */ |
1da177e4 LT |
40 | |
41 | #define SIGN_POS Const(0) | |
42 | #define SIGN_NEG Const(0x80) | |
43 | ||
44 | #define SIGN_Positive Const(0) | |
45 | #define SIGN_Negative Const(0x8000) | |
46 | ||
1da177e4 LT |
47 | /* Keep the order TAG_Valid, TAG_Zero, TW_Denormal */ |
48 | /* The following fold to 2 (Special) in the Tag Word */ | |
3d0d14f9 | 49 | #define TW_Denormal Const(4) /* De-normal */ |
1da177e4 LT |
50 | #define TW_Infinity Const(5) /* + or - infinity */ |
51 | #define TW_NaN Const(6) /* Not a Number */ | |
52 | #define TW_Unsupported Const(7) /* Not supported by an 80486 */ | |
53 | ||
54 | #define TAG_Valid Const(0) /* valid */ | |
55 | #define TAG_Zero Const(1) /* zero */ | |
56 | #define TAG_Special Const(2) /* De-normal, + or - infinity, | |
57 | or Not a Number */ | |
58 | #define TAG_Empty Const(3) /* empty */ | |
d606f88f | 59 | #define TAG_Error Const(0x80) /* probably need to abort */ |
1da177e4 LT |
60 | |
61 | #define LOADED_DATA Const(10101) /* Special st() number to identify | |
62 | loaded data (not on stack). */ | |
63 | ||
64 | /* A few flags (must be >= 0x10). */ | |
65 | #define REV 0x10 | |
66 | #define DEST_RM 0x20 | |
67 | #define LOADED 0x40 | |
68 | ||
3d0d14f9 | 69 | #define FPU_Exception Const(0x80000000) /* Added to tag returns. */ |
1da177e4 LT |
70 | |
71 | #ifndef __ASSEMBLY__ | |
72 | ||
73 | #include "fpu_system.h" | |
74 | ||
decb4c41 | 75 | #include <uapi/asm/sigcontext.h> /* for struct _fpstate */ |
1da177e4 LT |
76 | #include <asm/math_emu.h> |
77 | #include <linux/linkage.h> | |
78 | ||
79 | /* | |
80 | #define RE_ENTRANT_CHECKING | |
81 | */ | |
82 | ||
83 | #ifdef RE_ENTRANT_CHECKING | |
84 | extern u_char emulating; | |
85 | # define RE_ENTRANT_CHECK_OFF emulating = 0 | |
86 | # define RE_ENTRANT_CHECK_ON emulating = 1 | |
87 | #else | |
88 | # define RE_ENTRANT_CHECK_OFF | |
89 | # define RE_ENTRANT_CHECK_ON | |
90 | #endif /* RE_ENTRANT_CHECKING */ | |
91 | ||
92 | #define FWAIT_OPCODE 0x9b | |
93 | #define OP_SIZE_PREFIX 0x66 | |
94 | #define ADDR_SIZE_PREFIX 0x67 | |
95 | #define PREFIX_CS 0x2e | |
96 | #define PREFIX_DS 0x3e | |
97 | #define PREFIX_ES 0x26 | |
98 | #define PREFIX_SS 0x36 | |
99 | #define PREFIX_FS 0x64 | |
100 | #define PREFIX_GS 0x65 | |
101 | #define PREFIX_REPE 0xf3 | |
102 | #define PREFIX_REPNE 0xf2 | |
103 | #define PREFIX_LOCK 0xf0 | |
104 | #define PREFIX_CS_ 1 | |
105 | #define PREFIX_DS_ 2 | |
106 | #define PREFIX_ES_ 3 | |
107 | #define PREFIX_FS_ 4 | |
108 | #define PREFIX_GS_ 5 | |
109 | #define PREFIX_SS_ 6 | |
110 | #define PREFIX_DEFAULT 7 | |
111 | ||
112 | struct address { | |
3d0d14f9 IM |
113 | unsigned int offset; |
114 | unsigned int selector:16; | |
115 | unsigned int opcode:11; | |
116 | unsigned int empty:5; | |
1da177e4 LT |
117 | }; |
118 | struct fpu__reg { | |
3d0d14f9 IM |
119 | unsigned sigl; |
120 | unsigned sigh; | |
121 | short exp; | |
1da177e4 LT |
122 | }; |
123 | ||
3d0d14f9 | 124 | typedef void (*FUNC) (void); |
1da177e4 | 125 | typedef struct fpu__reg FPU_REG; |
e8d591dc | 126 | typedef void (*FUNC_ST0) (FPU_REG *st0_ptr, u_char st0_tag); |
3d0d14f9 IM |
127 | typedef struct { |
128 | u_char address_size, operand_size, segment; | |
129 | } overrides; | |
1da177e4 | 130 | /* This structure is 32 bits: */ |
3d0d14f9 IM |
131 | typedef struct { |
132 | overrides override; | |
133 | u_char default_mode; | |
134 | } fpu_addr_modes; | |
1da177e4 LT |
135 | /* PROTECTED has a restricted meaning in the emulator; it is used |
136 | to signal that the emulator needs to do special things to ensure | |
137 | that protection is respected in a segmented model. */ | |
138 | #define PROTECTED 4 | |
3d0d14f9 | 139 | #define SIXTEEN 1 /* We rely upon this being 1 (true) */ |
1da177e4 LT |
140 | #define VM86 SIXTEEN |
141 | #define PM16 (SIXTEEN | PROTECTED) | |
142 | #define SEG32 PROTECTED | |
143 | extern u_char const data_sizes_16[32]; | |
144 | ||
145 | #define register_base ((u_char *) registers ) | |
146 | #define fpu_register(x) ( * ((FPU_REG *)( register_base + 10 * (x & 7) )) ) | |
147 | #define st(x) ( * ((FPU_REG *)( register_base + 10 * ((top+x) & 7) )) ) | |
148 | ||
149 | #define STACK_OVERFLOW (FPU_stackoverflow(&st_new_ptr)) | |
150 | #define NOT_EMPTY(i) (!FPU_empty_i(i)) | |
151 | ||
152 | #define NOT_EMPTY_ST0 (st0_tag ^ TAG_Empty) | |
153 | ||
154 | #define poppop() { FPU_pop(); FPU_pop(); } | |
155 | ||
156 | /* push() does not affect the tags */ | |
157 | #define push() { top--; } | |
158 | ||
159 | #define signbyte(a) (((u_char *)(a))[9]) | |
160 | #define getsign(a) (signbyte(a) & 0x80) | |
5623452a | 161 | #define setsign(a,b) { if ((b) != 0) signbyte(a) |= 0x80; else signbyte(a) &= 0x7f; } |
1da177e4 LT |
162 | #define copysign(a,b) { if (getsign(a)) signbyte(b) |= 0x80; \ |
163 | else signbyte(b) &= 0x7f; } | |
164 | #define changesign(a) { signbyte(a) ^= 0x80; } | |
165 | #define setpositive(a) { signbyte(a) &= 0x7f; } | |
166 | #define setnegative(a) { signbyte(a) |= 0x80; } | |
167 | #define signpositive(a) ( (signbyte(a) & 0x80) == 0 ) | |
168 | #define signnegative(a) (signbyte(a) & 0x80) | |
169 | ||
e8d591dc | 170 | static inline void reg_copy(FPU_REG const *x, FPU_REG *y) |
1da177e4 | 171 | { |
3d0d14f9 IM |
172 | *(short *)&(y->exp) = *(const short *)&(x->exp); |
173 | *(long long *)&(y->sigl) = *(const long long *)&(x->sigl); | |
1da177e4 LT |
174 | } |
175 | ||
176 | #define exponent(x) (((*(short *)&((x)->exp)) & 0x7fff) - EXTENDED_Ebias) | |
177 | #define setexponentpos(x,y) { (*(short *)&((x)->exp)) = \ | |
178 | ((y) + EXTENDED_Ebias) & 0x7fff; } | |
179 | #define exponent16(x) (*(short *)&((x)->exp)) | |
180 | #define setexponent16(x,y) { (*(short *)&((x)->exp)) = (y); } | |
181 | #define addexponent(x,y) { (*(short *)&((x)->exp)) += (y); } | |
182 | #define stdexp(x) { (*(short *)&((x)->exp)) += EXTENDED_Ebias; } | |
183 | ||
184 | #define isdenormal(ptr) (exponent(ptr) == EXP_BIAS+EXP_UNDER) | |
185 | ||
186 | #define significand(x) ( ((unsigned long long *)&((x)->sigl))[0] ) | |
187 | ||
1da177e4 LT |
188 | /*----- Prototypes for functions written in assembler -----*/ |
189 | /* extern void reg_move(FPU_REG *a, FPU_REG *b); */ | |
190 | ||
e8d591dc IM |
191 | asmlinkage int FPU_normalize(FPU_REG *x); |
192 | asmlinkage int FPU_normalize_nuo(FPU_REG *x); | |
1da177e4 | 193 | asmlinkage int FPU_u_sub(FPU_REG const *arg1, FPU_REG const *arg2, |
3d0d14f9 | 194 | FPU_REG * answ, unsigned int control_w, u_char sign, |
1da177e4 LT |
195 | int expa, int expb); |
196 | asmlinkage int FPU_u_mul(FPU_REG const *arg1, FPU_REG const *arg2, | |
3d0d14f9 | 197 | FPU_REG * answ, unsigned int control_w, u_char sign, |
1da177e4 LT |
198 | int expon); |
199 | asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2, | |
3d0d14f9 | 200 | FPU_REG * answ, unsigned int control_w, u_char sign); |
1da177e4 | 201 | asmlinkage int FPU_u_add(FPU_REG const *arg1, FPU_REG const *arg2, |
3d0d14f9 | 202 | FPU_REG * answ, unsigned int control_w, u_char sign, |
1da177e4 | 203 | int expa, int expb); |
e8d591dc | 204 | asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2, |
1da177e4 | 205 | unsigned int control_w, u_char sign); |
3d0d14f9 IM |
206 | asmlinkage unsigned FPU_shrx(void *l, unsigned x); |
207 | asmlinkage unsigned FPU_shrxs(void *v, unsigned x); | |
1da177e4 | 208 | asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y); |
e8d591dc | 209 | asmlinkage int FPU_round(FPU_REG *arg, unsigned int extent, int dummy, |
1da177e4 LT |
210 | unsigned int control_w, u_char sign); |
211 | ||
212 | #ifndef MAKING_PROTO | |
213 | #include "fpu_proto.h" | |
214 | #endif | |
215 | ||
216 | #endif /* __ASSEMBLY__ */ | |
217 | ||
218 | #endif /* _FPU_EMU_H_ */ |