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*/
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 |
8 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
9 | Australia. E-mail apm233m@vaxc.cc.monash.edu.au |
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/segment.h>
22
23 #include "fpu_system.h"
24 #include "exception.h"
25 #include "fpu_emu.h"
26 #include "status_w.h"
27
28
29 #define _NONE_ 0 /* FPU_st0_ptr etc not needed */
30 #define _REG0_ 1 /* Will be storing st(0) */
31 #define _PUSH_ 3 /* Need to check for space to push onto stack */
32 #define _null_ 4 /* Function illegal or not implemented */
33
34 #define pop_0() { pop_ptr->tag = TW_Empty; top++; }
35
36
37 static unsigned char type_table[32] = {
38 _PUSH_, _PUSH_, _PUSH_, _PUSH_,
39 _null_, _null_, _null_, _null_,
40 _REG0_, _REG0_, _REG0_, _REG0_,
41 _REG0_, _REG0_, _REG0_, _REG0_,
42 _NONE_, _null_, _NONE_, _PUSH_,
43 _NONE_, _PUSH_, _null_, _PUSH_,
44 _NONE_, _null_, _NONE_, _REG0_,
45 _NONE_, _REG0_, _NONE_, _REG0_
46 };
47
48 void load_store_instr(char type)
/* ![[first]](../icons/n_first.png)
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*/
49 {
50 FPU_REG *pop_ptr; /* We need a version of FPU_st0_ptr which won't change. */
51
52 pop_ptr = NULL; /* Initialized just to stop compiler warnings. */
53 switch ( type_table[(int) (unsigned) type] )
54 {
55 case _NONE_:
56 break;
57 case _REG0_:
58 pop_ptr = &st(0); /* Some of these instructions pop after
59 storing */
60
61 FPU_st0_ptr = pop_ptr; /* Set the global variables. */
62 FPU_st0_tag = FPU_st0_ptr->tag;
63 break;
64 case _PUSH_:
65 {
66 pop_ptr = &st(-1);
67 if ( pop_ptr->tag != TW_Empty )
68 { stack_overflow(); return; }
69 top--;
70 }
71 break;
72 case _null_:
73 Un_impl();
74 return;
75 #ifdef PARANOID
76 default:
77 EXCEPTION(EX_INTERNAL);
78 return;
79 #endif PARANOID
80 }
81
82 switch ( type )
83 {
84 case 000: /* fld m32real */
85 reg_load_single();
86 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
87 reg_move(&FPU_loaded_data, pop_ptr);
88 break;
89 case 001: /* fild m32int */
90 reg_load_int32();
91 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
92 reg_move(&FPU_loaded_data, pop_ptr);
93 break;
94 case 002: /* fld m64real */
95 reg_load_double();
96 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
97 reg_move(&FPU_loaded_data, pop_ptr);
98 break;
99 case 003: /* fild m16int */
100 reg_load_int16();
101 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
102 reg_move(&FPU_loaded_data, pop_ptr);
103 break;
104 case 010: /* fst m32real */
105 reg_store_single();
106 break;
107 case 011: /* fist m32int */
108 reg_store_int32();
109 break;
110 case 012: /* fst m64real */
111 reg_store_double();
112 break;
113 case 013: /* fist m16int */
114 reg_store_int16();
115 break;
116 case 014: /* fstp m32real */
117 if ( reg_store_single() )
118 pop_0(); /* pop only if the number was actually stored
119 (see the 80486 manual p16-28) */
120 break;
121 case 015: /* fistp m32int */
122 if ( reg_store_int32() )
123 pop_0(); /* pop only if the number was actually stored
124 (see the 80486 manual p16-28) */
125 break;
126 case 016: /* fstp m64real */
127 if ( reg_store_double() )
128 pop_0(); /* pop only if the number was actually stored
129 (see the 80486 manual p16-28) */
130 break;
131 case 017: /* fistp m16int */
132 if ( reg_store_int16() )
133 pop_0(); /* pop only if the number was actually stored
134 (see the 80486 manual p16-28) */
135 break;
136 case 020: /* fldenv m14/28byte */
137 fldenv();
138 break;
139 case 022: /* frstor m94/108byte */
140 frstor();
141 break;
142 case 023: /* fbld m80dec */
143 reg_load_bcd();
144 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
145 reg_move(&FPU_loaded_data, pop_ptr);
146 break;
147 case 024: /* fldcw */
148 RE_ENTRANT_CHECK_OFF
149 control_word = get_fs_word((unsigned short *) FPU_data_address);
150 RE_ENTRANT_CHECK_ON
151 #ifdef NO_UNDERFLOW_TRAP
152 if ( !(control_word & EX_Underflow) )
153 {
154 control_word |= EX_Underflow;
155 }
156 #endif
157 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
158 FPU_entry_eip = ip_offset; /* We want no net effect */
159 break;
160 case 025: /* fld m80real */
161 reg_load_extended();
162 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
163 reg_move(&FPU_loaded_data, pop_ptr);
164 break;
165 case 027: /* fild m64int */
166 reg_load_int64();
167 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
168 reg_move(&FPU_loaded_data, pop_ptr);
169 break;
170 case 030: /* fstenv m14/28byte */
171 fstenv();
172 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
173 FPU_entry_eip = ip_offset; /* We want no net effect */
174 break;
175 case 032: /* fsave */
176 fsave();
177 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
178 FPU_entry_eip = ip_offset; /* We want no net effect */
179 break;
180 case 033: /* fbstp m80dec */
181 if ( reg_store_bcd() )
182 pop_0(); /* pop only if the number was actually stored
183 (see the 80486 manual p16-28) */
184 break;
185 case 034: /* fstcw m16int */
186 RE_ENTRANT_CHECK_OFF
187 verify_area(VERIFY_WRITE,FPU_data_address,2);
188 put_fs_word(control_word, (short *) FPU_data_address);
189 RE_ENTRANT_CHECK_ON
190 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
191 FPU_entry_eip = ip_offset; /* We want no net effect */
192 break;
193 case 035: /* fstp m80real */
194 if ( reg_store_extended() )
195 pop_0(); /* pop only if the number was actually stored
196 (see the 80486 manual p16-28) */
197 break;
198 case 036: /* fstsw m2byte */
199 status_word &= ~SW_Top;
200 status_word |= (top&7) << SW_Top_Shift;
201 RE_ENTRANT_CHECK_OFF
202 verify_area(VERIFY_WRITE,FPU_data_address,2);
203 put_fs_word(status_word,(short *) FPU_data_address);
204 RE_ENTRANT_CHECK_ON
205 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
206 FPU_entry_eip = ip_offset; /* We want no net effect */
207 break;
208 case 037: /* fistp m64int */
209 if ( reg_store_int64() )
210 pop_0(); /* pop only if the number was actually stored
211 (see the 80486 manual p16-28) */
212 break;
213 }
214 }
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*/