File: /usr/src/linux/arch/i386/math-emu/load_store.c
1 /*---------------------------------------------------------------------------+
2 | load_store.c |
3 | |
4 | This file contains most of the code to interpret the FPU instructions |
5 | which load and store from user memory. |
6 | |
7 | Copyright (C) 1992,1993,1994,1997 |
8 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
9 | Australia. E-mail billm@suburbia.net |
10 | |
11 | |
12 +---------------------------------------------------------------------------*/
13
14 /*---------------------------------------------------------------------------+
15 | Note: |
16 | The file contains code which accesses user memory. |
17 | Emulator static data may change when user memory is accessed, due to |
18 | other processes using the emulator while swapping is in progress. |
19 +---------------------------------------------------------------------------*/
20
21 #include <asm/uaccess.h>
22
23 #include "fpu_system.h"
24 #include "exception.h"
25 #include "fpu_emu.h"
26 #include "status_w.h"
27 #include "control_w.h"
28
29
30 #define _NONE_ 0 /* st0_ptr etc not needed */
31 #define _REG0_ 1 /* Will be storing st(0) */
32 #define _PUSH_ 3 /* Need to check for space to push onto stack */
33 #define _null_ 4 /* Function illegal or not implemented */
34
35 #define pop_0() { FPU_settag0(TAG_Empty); top++; }
36
37
38 static u_char const type_table[32] = {
39 _PUSH_, _PUSH_, _PUSH_, _PUSH_,
40 _null_, _null_, _null_, _null_,
41 _REG0_, _REG0_, _REG0_, _REG0_,
42 _REG0_, _REG0_, _REG0_, _REG0_,
43 _NONE_, _null_, _NONE_, _PUSH_,
44 _NONE_, _PUSH_, _null_, _PUSH_,
45 _NONE_, _null_, _NONE_, _REG0_,
46 _NONE_, _REG0_, _NONE_, _REG0_
47 };
48
49 u_char const data_sizes_16[32] = {
50 4, 4, 8, 2, 0, 0, 0, 0,
51 4, 4, 8, 2, 4, 4, 8, 2,
52 14, 0, 94, 10, 2, 10, 0, 8,
53 14, 0, 94, 10, 2, 10, 2, 8
54 };
55
56 u_char const data_sizes_32[32] = {
57 4, 4, 8, 2, 0, 0, 0, 0,
58 4, 4, 8, 2, 4, 4, 8, 2,
59 28, 0,108, 10, 2, 10, 0, 8,
60 28, 0,108, 10, 2, 10, 2, 8
61 };
62
63 int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
64 void *data_address)
65 {
66 FPU_REG loaded_data;
67 FPU_REG *st0_ptr;
68 u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */
69 u_char loaded_tag;
70
71 st0_ptr = NULL; /* Initialized just to stop compiler warnings. */
72
73 if ( addr_modes.default_mode & PROTECTED )
74 {
75 if ( addr_modes.default_mode == SEG32 )
76 {
77 if ( access_limit < data_sizes_32[type] )
78 math_abort(FPU_info,SIGSEGV);
79 }
80 else if ( addr_modes.default_mode == PM16 )
81 {
82 if ( access_limit < data_sizes_16[type] )
83 math_abort(FPU_info,SIGSEGV);
84 }
85 #ifdef PARANOID
86 else
87 EXCEPTION(EX_INTERNAL|0x140);
88 #endif /* PARANOID */
89 }
90
91 switch ( type_table[type] )
92 {
93 case _NONE_:
94 break;
95 case _REG0_:
96 st0_ptr = &st(0); /* Some of these instructions pop after
97 storing */
98 st0_tag = FPU_gettag0();
99 break;
100 case _PUSH_:
101 {
102 if ( FPU_gettagi(-1) != TAG_Empty )
103 { FPU_stack_overflow(); return 0; }
104 top--;
105 st0_ptr = &st(0);
106 }
107 break;
108 case _null_:
109 FPU_illegal();
110 return 0;
111 #ifdef PARANOID
112 default:
113 EXCEPTION(EX_INTERNAL|0x141);
114 return 0;
115 #endif /* PARANOID */
116 }
117
118 switch ( type )
119 {
120 case 000: /* fld m32real */
121 clear_C1();
122 loaded_tag = FPU_load_single((float *)data_address, &loaded_data);
123 if ( (loaded_tag == TAG_Special)
124 && isNaN(&loaded_data)
125 && (real_1op_NaN(&loaded_data) < 0) )
126 {
127 top++;
128 break;
129 }
130 FPU_copy_to_reg0(&loaded_data, loaded_tag);
131 break;
132 case 001: /* fild m32int */
133 clear_C1();
134 loaded_tag = FPU_load_int32((long *)data_address, &loaded_data);
135 FPU_copy_to_reg0(&loaded_data, loaded_tag);
136 break;
137 case 002: /* fld m64real */
138 clear_C1();
139 loaded_tag = FPU_load_double((double *)data_address, &loaded_data);
140 if ( (loaded_tag == TAG_Special)
141 && isNaN(&loaded_data)
142 && (real_1op_NaN(&loaded_data) < 0) )
143 {
144 top++;
145 break;
146 }
147 FPU_copy_to_reg0(&loaded_data, loaded_tag);
148 break;
149 case 003: /* fild m16int */
150 clear_C1();
151 loaded_tag = FPU_load_int16((short *)data_address, &loaded_data);
152 FPU_copy_to_reg0(&loaded_data, loaded_tag);
153 break;
154 case 010: /* fst m32real */
155 clear_C1();
156 FPU_store_single(st0_ptr, st0_tag, (float *)data_address);
157 break;
158 case 011: /* fist m32int */
159 clear_C1();
160 FPU_store_int32(st0_ptr, st0_tag, (long *)data_address);
161 break;
162 case 012: /* fst m64real */
163 clear_C1();
164 FPU_store_double(st0_ptr, st0_tag, (double *)data_address);
165 break;
166 case 013: /* fist m16int */
167 clear_C1();
168 FPU_store_int16(st0_ptr, st0_tag, (short *)data_address);
169 break;
170 case 014: /* fstp m32real */
171 clear_C1();
172 if ( FPU_store_single(st0_ptr, st0_tag, (float *)data_address) )
173 pop_0(); /* pop only if the number was actually stored
174 (see the 80486 manual p16-28) */
175 break;
176 case 015: /* fistp m32int */
177 clear_C1();
178 if ( FPU_store_int32(st0_ptr, st0_tag, (long *)data_address) )
179 pop_0(); /* pop only if the number was actually stored
180 (see the 80486 manual p16-28) */
181 break;
182 case 016: /* fstp m64real */
183 clear_C1();
184 if ( FPU_store_double(st0_ptr, st0_tag, (double *)data_address) )
185 pop_0(); /* pop only if the number was actually stored
186 (see the 80486 manual p16-28) */
187 break;
188 case 017: /* fistp m16int */
189 clear_C1();
190 if ( FPU_store_int16(st0_ptr, st0_tag, (short *)data_address) )
191 pop_0(); /* pop only if the number was actually stored
192 (see the 80486 manual p16-28) */
193 break;
194 case 020: /* fldenv m14/28byte */
195 fldenv(addr_modes, (u_char *)data_address);
196 /* Ensure that the values just loaded are not changed by
197 fix-up operations. */
198 return 1;
199 case 022: /* frstor m94/108byte */
200 frstor(addr_modes, (u_char *)data_address);
201 /* Ensure that the values just loaded are not changed by
202 fix-up operations. */
203 return 1;
204 case 023: /* fbld m80dec */
205 clear_C1();
206 loaded_tag = FPU_load_bcd((u_char *)data_address);
207 FPU_settag0(loaded_tag);
208 break;
209 case 024: /* fldcw */
210 RE_ENTRANT_CHECK_OFF;
211 FPU_verify_area(VERIFY_READ, data_address, 2);
212 FPU_get_user(control_word, (unsigned short *) data_address);
213 RE_ENTRANT_CHECK_ON;
214 if ( partial_status & ~control_word & CW_Exceptions )
215 partial_status |= (SW_Summary | SW_Backward);
216 else
217 partial_status &= ~(SW_Summary | SW_Backward);
218 #ifdef PECULIAR_486
219 control_word |= 0x40; /* An 80486 appears to always set this bit */
220 #endif /* PECULIAR_486 */
221 return 1;
222 case 025: /* fld m80real */
223 clear_C1();
224 loaded_tag = FPU_load_extended((long double *)data_address, 0);
225 FPU_settag0(loaded_tag);
226 break;
227 case 027: /* fild m64int */
228 clear_C1();
229 loaded_tag = FPU_load_int64((long long *)data_address);
230 FPU_settag0(loaded_tag);
231 break;
232 case 030: /* fstenv m14/28byte */
233 fstenv(addr_modes, (u_char *)data_address);
234 return 1;
235 case 032: /* fsave */
236 fsave(addr_modes, (u_char *)data_address);
237 return 1;
238 case 033: /* fbstp m80dec */
239 clear_C1();
240 if ( FPU_store_bcd(st0_ptr, st0_tag, (u_char *)data_address) )
241 pop_0(); /* pop only if the number was actually stored
242 (see the 80486 manual p16-28) */
243 break;
244 case 034: /* fstcw m16int */
245 RE_ENTRANT_CHECK_OFF;
246 FPU_verify_area(VERIFY_WRITE,data_address,2);
247 FPU_put_user(control_word, (unsigned short *) data_address);
248 RE_ENTRANT_CHECK_ON;
249 return 1;
250 case 035: /* fstp m80real */
251 clear_C1();
252 if ( FPU_store_extended(st0_ptr, st0_tag, (long double *)data_address) )
253 pop_0(); /* pop only if the number was actually stored
254 (see the 80486 manual p16-28) */
255 break;
256 case 036: /* fstsw m2byte */
257 RE_ENTRANT_CHECK_OFF;
258 FPU_verify_area(VERIFY_WRITE,data_address,2);
259 FPU_put_user(status_word(),(unsigned short *) data_address);
260 RE_ENTRANT_CHECK_ON;
261 return 1;
262 case 037: /* fistp m64int */
263 clear_C1();
264 if ( FPU_store_int64(st0_ptr, st0_tag, (long long *)data_address) )
265 pop_0(); /* pop only if the number was actually stored
266 (see the 80486 manual p16-28) */
267 break;
268 }
269 return 0;
270 }
271