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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*---------------------------------------------------------------------------+
2 | fpu_emu.h |
3 | |
4 | Copyright (C) 1992,1993,1994,1997 |
5 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
6 | Australia. E-mail billm@suburbia.net |
7 | |
8 +---------------------------------------------------------------------------*/
9
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#ifndef _FPU_EMU_H_
11#define _FPU_EMU_H_
12
13/*
14 * Define PECULIAR_486 to get a closer approximation to 80486 behaviour,
15 * rather than behaviour which appears to be cleaner.
16 * This is a matter of opinion: for all I know, the 80486 may simply
17 * be complying with the IEEE spec. Maybe one day I'll get to see the
18 * spec...
19 */
20#define PECULIAR_486
21
22#ifdef __ASSEMBLY__
23#include "fpu_asm.h"
24#define Const(x) $##x
25#else
26#define Const(x) x
27#endif
28
29#define EXP_BIAS Const(0)
Ingo Molnar3d0d14f2008-01-30 13:30:11 +010030#define EXP_OVER Const(0x4000) /* smallest invalid large exponent */
31#define EXP_UNDER Const(-0x3fff) /* largest invalid small exponent */
32#define EXP_WAY_UNDER Const(-0x6000) /* Below the smallest denormal, but
33 still a 16 bit nr. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#define EXP_Infinity EXP_OVER
35#define EXP_NaN EXP_OVER
36
37#define EXTENDED_Ebias Const(0x3fff)
Ingo Molnar3d0d14f2008-01-30 13:30:11 +010038#define EXTENDED_Emin (-0x3ffe) /* smallest valid exponent */
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#define SIGN_POS Const(0)
41#define SIGN_NEG Const(0x80)
42
43#define SIGN_Positive Const(0)
44#define SIGN_Negative Const(0x8000)
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046/* Keep the order TAG_Valid, TAG_Zero, TW_Denormal */
47/* The following fold to 2 (Special) in the Tag Word */
Ingo Molnar3d0d14f2008-01-30 13:30:11 +010048#define TW_Denormal Const(4) /* De-normal */
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#define TW_Infinity Const(5) /* + or - infinity */
50#define TW_NaN Const(6) /* Not a Number */
51#define TW_Unsupported Const(7) /* Not supported by an 80486 */
52
53#define TAG_Valid Const(0) /* valid */
54#define TAG_Zero Const(1) /* zero */
55#define TAG_Special Const(2) /* De-normal, + or - infinity,
56 or Not a Number */
57#define TAG_Empty Const(3) /* empty */
Randy Dunlapd606f882006-12-07 02:14:00 +010058#define TAG_Error Const(0x80) /* probably need to abort */
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60#define LOADED_DATA Const(10101) /* Special st() number to identify
61 loaded data (not on stack). */
62
63/* A few flags (must be >= 0x10). */
64#define REV 0x10
65#define DEST_RM 0x20
66#define LOADED 0x40
67
Ingo Molnar3d0d14f2008-01-30 13:30:11 +010068#define FPU_Exception Const(0x80000000) /* Added to tag returns. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70#ifndef __ASSEMBLY__
71
72#include "fpu_system.h"
73
Ingo Molnar3d0d14f2008-01-30 13:30:11 +010074#include <asm/sigcontext.h> /* for struct _fpstate */
Linus Torvalds1da177e2005-04-16 15:20:36 -070075#include <asm/math_emu.h>
76#include <linux/linkage.h>
77
78/*
79#define RE_ENTRANT_CHECKING
80 */
81
82#ifdef RE_ENTRANT_CHECKING
83extern u_char emulating;
84# define RE_ENTRANT_CHECK_OFF emulating = 0
85# define RE_ENTRANT_CHECK_ON emulating = 1
86#else
87# define RE_ENTRANT_CHECK_OFF
88# define RE_ENTRANT_CHECK_ON
89#endif /* RE_ENTRANT_CHECKING */
90
91#define FWAIT_OPCODE 0x9b
92#define OP_SIZE_PREFIX 0x66
93#define ADDR_SIZE_PREFIX 0x67
94#define PREFIX_CS 0x2e
95#define PREFIX_DS 0x3e
96#define PREFIX_ES 0x26
97#define PREFIX_SS 0x36
98#define PREFIX_FS 0x64
99#define PREFIX_GS 0x65
100#define PREFIX_REPE 0xf3
101#define PREFIX_REPNE 0xf2
102#define PREFIX_LOCK 0xf0
103#define PREFIX_CS_ 1
104#define PREFIX_DS_ 2
105#define PREFIX_ES_ 3
106#define PREFIX_FS_ 4
107#define PREFIX_GS_ 5
108#define PREFIX_SS_ 6
109#define PREFIX_DEFAULT 7
110
111struct address {
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100112 unsigned int offset;
113 unsigned int selector:16;
114 unsigned int opcode:11;
115 unsigned int empty:5;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116};
117struct fpu__reg {
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100118 unsigned sigl;
119 unsigned sigh;
120 short exp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121};
122
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100123typedef void (*FUNC) (void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124typedef struct fpu__reg FPU_REG;
Ingo Molnare8d591d2008-01-30 13:30:12 +0100125typedef void (*FUNC_ST0) (FPU_REG *st0_ptr, u_char st0_tag);
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100126typedef struct {
127 u_char address_size, operand_size, segment;
128} overrides;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129/* This structure is 32 bits: */
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100130typedef struct {
131 overrides override;
132 u_char default_mode;
133} fpu_addr_modes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134/* PROTECTED has a restricted meaning in the emulator; it is used
135 to signal that the emulator needs to do special things to ensure
136 that protection is respected in a segmented model. */
137#define PROTECTED 4
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100138#define SIXTEEN 1 /* We rely upon this being 1 (true) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139#define VM86 SIXTEEN
140#define PM16 (SIXTEEN | PROTECTED)
141#define SEG32 PROTECTED
142extern u_char const data_sizes_16[32];
143
144#define register_base ((u_char *) registers )
145#define fpu_register(x) ( * ((FPU_REG *)( register_base + 10 * (x & 7) )) )
146#define st(x) ( * ((FPU_REG *)( register_base + 10 * ((top+x) & 7) )) )
147
148#define STACK_OVERFLOW (FPU_stackoverflow(&st_new_ptr))
149#define NOT_EMPTY(i) (!FPU_empty_i(i))
150
151#define NOT_EMPTY_ST0 (st0_tag ^ TAG_Empty)
152
153#define poppop() { FPU_pop(); FPU_pop(); }
154
155/* push() does not affect the tags */
156#define push() { top--; }
157
158#define signbyte(a) (((u_char *)(a))[9])
159#define getsign(a) (signbyte(a) & 0x80)
160#define setsign(a,b) { if (b) signbyte(a) |= 0x80; else signbyte(a) &= 0x7f; }
161#define copysign(a,b) { if (getsign(a)) signbyte(b) |= 0x80; \
162 else signbyte(b) &= 0x7f; }
163#define changesign(a) { signbyte(a) ^= 0x80; }
164#define setpositive(a) { signbyte(a) &= 0x7f; }
165#define setnegative(a) { signbyte(a) |= 0x80; }
166#define signpositive(a) ( (signbyte(a) & 0x80) == 0 )
167#define signnegative(a) (signbyte(a) & 0x80)
168
Ingo Molnare8d591d2008-01-30 13:30:12 +0100169static inline void reg_copy(FPU_REG const *x, FPU_REG *y)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170{
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100171 *(short *)&(y->exp) = *(const short *)&(x->exp);
172 *(long long *)&(y->sigl) = *(const long long *)&(x->sigl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173}
174
175#define exponent(x) (((*(short *)&((x)->exp)) & 0x7fff) - EXTENDED_Ebias)
176#define setexponentpos(x,y) { (*(short *)&((x)->exp)) = \
177 ((y) + EXTENDED_Ebias) & 0x7fff; }
178#define exponent16(x) (*(short *)&((x)->exp))
179#define setexponent16(x,y) { (*(short *)&((x)->exp)) = (y); }
180#define addexponent(x,y) { (*(short *)&((x)->exp)) += (y); }
181#define stdexp(x) { (*(short *)&((x)->exp)) += EXTENDED_Ebias; }
182
183#define isdenormal(ptr) (exponent(ptr) == EXP_BIAS+EXP_UNDER)
184
185#define significand(x) ( ((unsigned long long *)&((x)->sigl))[0] )
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187/*----- Prototypes for functions written in assembler -----*/
188/* extern void reg_move(FPU_REG *a, FPU_REG *b); */
189
Ingo Molnare8d591d2008-01-30 13:30:12 +0100190asmlinkage int FPU_normalize(FPU_REG *x);
191asmlinkage int FPU_normalize_nuo(FPU_REG *x);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192asmlinkage int FPU_u_sub(FPU_REG const *arg1, FPU_REG const *arg2,
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100193 FPU_REG * answ, unsigned int control_w, u_char sign,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 int expa, int expb);
195asmlinkage int FPU_u_mul(FPU_REG const *arg1, FPU_REG const *arg2,
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100196 FPU_REG * answ, unsigned int control_w, u_char sign,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 int expon);
198asmlinkage int FPU_u_div(FPU_REG const *arg1, FPU_REG const *arg2,
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100199 FPU_REG * answ, unsigned int control_w, u_char sign);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200asmlinkage int FPU_u_add(FPU_REG const *arg1, FPU_REG const *arg2,
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100201 FPU_REG * answ, unsigned int control_w, u_char sign,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 int expa, int expb);
Ingo Molnare8d591d2008-01-30 13:30:12 +0100203asmlinkage int wm_sqrt(FPU_REG *n, int dummy1, int dummy2,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 unsigned int control_w, u_char sign);
Ingo Molnar3d0d14f2008-01-30 13:30:11 +0100205asmlinkage unsigned FPU_shrx(void *l, unsigned x);
206asmlinkage unsigned FPU_shrxs(void *v, unsigned x);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207asmlinkage unsigned long FPU_div_small(unsigned long long *x, unsigned long y);
Ingo Molnare8d591d2008-01-30 13:30:12 +0100208asmlinkage int FPU_round(FPU_REG *arg, unsigned int extent, int dummy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 unsigned int control_w, u_char sign);
210
211#ifndef MAKING_PROTO
212#include "fpu_proto.h"
213#endif
214
215#endif /* __ASSEMBLY__ */
216
217#endif /* _FPU_EMU_H_ */