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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 return Un_impl();
74 #ifdef PARANOID
75 default:
76 return EXCEPTION(EX_INTERNAL);
77 #endif PARANOID
78 }
79
80 switch ( type )
81 {
82 case 000: /* fld m32real */
83 reg_load_single();
84 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
85 reg_move(&FPU_loaded_data, pop_ptr);
86 break;
87 case 001: /* fild m32int */
88 reg_load_int32();
89 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
90 reg_move(&FPU_loaded_data, pop_ptr);
91 break;
92 case 002: /* fld m64real */
93 reg_load_double();
94 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
95 reg_move(&FPU_loaded_data, pop_ptr);
96 break;
97 case 003: /* fild m16int */
98 reg_load_int16();
99 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
100 reg_move(&FPU_loaded_data, pop_ptr);
101 break;
102 case 010: /* fst m32real */
103 reg_store_single();
104 break;
105 case 011: /* fist m32int */
106 reg_store_int32();
107 break;
108 case 012: /* fst m64real */
109 reg_store_double();
110 break;
111 case 013: /* fist m16int */
112 reg_store_int16();
113 break;
114 case 014: /* fstp m32real */
115 if ( reg_store_single() )
116 pop_0(); /* pop only if the number was actually stored
117 (see the 80486 manual p16-28) */
118 break;
119 case 015: /* fistp m32int */
120 if ( reg_store_int32() )
121 pop_0(); /* pop only if the number was actually stored
122 (see the 80486 manual p16-28) */
123 break;
124 case 016: /* fstp m64real */
125 if ( reg_store_double() )
126 pop_0(); /* pop only if the number was actually stored
127 (see the 80486 manual p16-28) */
128 break;
129 case 017: /* fistp m16int */
130 if ( reg_store_int16() )
131 pop_0(); /* pop only if the number was actually stored
132 (see the 80486 manual p16-28) */
133 break;
134 case 020: /* fldenv m14/28byte */
135 fldenv();
136 break;
137 case 022: /* frstor m94/108byte */
138 frstor();
139 break;
140 case 023: /* fbld m80dec */
141 reg_load_bcd();
142 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
143 reg_move(&FPU_loaded_data, pop_ptr);
144 break;
145 case 024: /* fldcw */
146 RE_ENTRANT_CHECK_OFF
147 control_word = get_fs_word((unsigned short *) FPU_data_address);
148 RE_ENTRANT_CHECK_ON
149 #ifdef NO_UNDERFLOW_TRAP
150 if ( !(control_word & EX_Underflow) )
151 {
152 control_word |= EX_Underflow;
153 }
154 #endif
155 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
156 FPU_entry_eip = ip_offset; /* We want no net effect */
157 break;
158 case 025: /* fld m80real */
159 reg_load_extended();
160 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
161 reg_move(&FPU_loaded_data, pop_ptr);
162 break;
163 case 027: /* fild m64int */
164 reg_load_int64();
165 setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */
166 reg_move(&FPU_loaded_data, pop_ptr);
167 break;
168 case 030: /* fstenv m14/28byte */
169 fstenv();
170 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
171 FPU_entry_eip = ip_offset; /* We want no net effect */
172 break;
173 case 032: /* fsave */
174 fsave();
175 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
176 FPU_entry_eip = ip_offset; /* We want no net effect */
177 break;
178 case 033: /* fbstp m80dec */
179 if ( reg_store_bcd() )
180 pop_0(); /* pop only if the number was actually stored
181 (see the 80486 manual p16-28) */
182 break;
183 case 034: /* fstcw m16int */
184 RE_ENTRANT_CHECK_OFF
185 verify_area(VERIFY_WRITE,FPU_data_address,2);
186 put_fs_word(control_word, (short *) FPU_data_address);
187 RE_ENTRANT_CHECK_ON
188 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
189 FPU_entry_eip = ip_offset; /* We want no net effect */
190 break;
191 case 035: /* fstp m80real */
192 if ( reg_store_extended() )
193 pop_0(); /* pop only if the number was actually stored
194 (see the 80486 manual p16-28) */
195 break;
196 case 036: /* fstsw m2byte */
197 status_word &= ~SW_Top;
198 status_word |= (top&7) << SW_Top_Shift;
199 RE_ENTRANT_CHECK_OFF
200 verify_area(VERIFY_WRITE,FPU_data_address,2);
201 put_fs_word(status_word,(short *) FPU_data_address);
202 RE_ENTRANT_CHECK_ON
203 FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
204 FPU_entry_eip = ip_offset; /* We want no net effect */
205 break;
206 case 037: /* fistp m64int */
207 if ( reg_store_int64() )
208 pop_0(); /* pop only if the number was actually stored
209 (see the 80486 manual p16-28) */
210 break;
211 }
212 }
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*/