aboutsummaryrefslogtreecommitdiff
path: root/source/cpuaddr.h
blob: 6f5e9300cab8b595bfff22430c18f32fd0ea990c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
#include "../copyright"

#ifndef _CPUADDR_H_
#define _CPUADDR_H_

typedef enum
{
   NONE = 0,
   READ = 1,
   WRITE = 2,
   MODIFY = 3,
   JUMP = 4
} AccessMode;

// The type for a function that can run after the addressing mode is resolved:
typedef void (*InternalOp)(long);

static void Immediate8(AccessMode a, InternalOp op)
{
   long Addr = ICPU.ShiftedPB + CPU.PC - CPU.PCBase;
   CPU.PC++;
   (*op)(Addr);
}

static void Immediate16(AccessMode a, InternalOp op)
{
   long Addr = ICPU.ShiftedPB + CPU.PC - CPU.PCBase;
   CPU.PC += 2;
   (*op)(Addr);
}

static void Relative(AccessMode a, InternalOp op)
{
   int8_t Int8 = *CPU.PC++;
   long Addr = ((intptr_t)(CPU.PC - CPU.PCBase) + Int8) & 0xffff;
   (*op)(Addr);
}

static void RelativeLong(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = *(uint16_t*) CPU.PC;
#else
   Addr = *CPU.PC + (*(CPU.PC + 1) << 8);
#endif
   CPU.PC += 2;
   Addr += (CPU.PC - CPU.PCBase);
   Addr &= 0xffff;
   (*op)(Addr);
}

static void AbsoluteIndexedIndirect(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = (ICPU.Registers.X.W + * (uint16_t*) CPU.PC) & 0xffff;
#else
   Addr = (ICPU.Registers.X.W + *CPU.PC + (*(CPU.PC + 1) << 8)) & 0xffff;
#endif
   OpenBus = *(CPU.PC + 1);
   CPU.PC += 2;
   Addr = S9xGetWord(ICPU.ShiftedPB + Addr);
   if (a & READ) OpenBus = (uint8_t)(Addr >> 8);
   (*op)(Addr);
}

static void AbsoluteIndirectLong(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = *(uint16_t*) CPU.PC;
#else
   Addr = *CPU.PC + (*(CPU.PC + 1) << 8);
#endif

   OpenBus = *(CPU.PC + 1);
   CPU.PC += 2;
   if (a & READ)
      Addr = S9xGetWord(Addr) | ((OpenBus = S9xGetByte(Addr + 2)) << 16);
   else
      Addr = S9xGetWord(Addr) | (S9xGetByte(Addr + 2) << 16);
   (*op)(Addr);
}

static void AbsoluteIndirect(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = *(uint16_t*) CPU.PC;
#else
   Addr = *CPU.PC + (*(CPU.PC + 1) << 8);
#endif

   OpenBus = *(CPU.PC + 1);
   CPU.PC += 2;
   Addr = S9xGetWord(Addr);
   if (a & READ) OpenBus = (uint8_t)(Addr >> 8);
   Addr += ICPU.ShiftedPB;
   (*op)(Addr);
}

static void Absolute(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = *(uint16_t*) CPU.PC + ICPU.ShiftedDB;
#else
   Addr = *CPU.PC + (*(CPU.PC + 1) << 8) + ICPU.ShiftedDB;
#endif
   if (a & READ) OpenBus = *(CPU.PC + 1);
   CPU.PC += 2;
   (*op)(Addr);
}

static void AbsoluteLong(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = (*(uint32_t*) CPU.PC) & 0xffffff;
#elif defined FAST_ALIGNED_LSB_WORD_ACCESS
   if (((intptr_t) CPU.PC & 1) == 0)
      Addr = (*(uint16_t*) CPU.PC) + (*(CPU.PC + 2) << 16);
   else
      Addr = *CPU.PC + ((*(uint16_t*)(CPU.PC + 1)) << 8);
#else
   Addr = *CPU.PC + (*(CPU.PC + 1) << 8) + (*(CPU.PC + 2) << 16);
#endif
   if (a & READ) OpenBus = *(CPU.PC + 2);
   CPU.PC += 3;
   (*op)(Addr);
}

static void Direct(AccessMode a, InternalOp op)
{
   if (a & READ) OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W) & 0xffff;
   (*op)(Addr);
}

static void DirectIndirectIndexed(AccessMode a, InternalOp op)
{
   OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W) & 0xffff;

   Addr = S9xGetWord(Addr);
   if (a & READ) OpenBus = (uint8_t)(Addr >> 8);
   Addr += ICPU.ShiftedDB + ICPU.Registers.Y.W;

   // XXX: always add one if STA
   // XXX: else Add one cycle if crosses page boundary
   (*op)(Addr);
}

static void DirectIndirectIndexedLong(AccessMode a, InternalOp op)
{
   OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W) & 0xffff;

   if (a & READ)
      Addr = S9xGetWord(Addr) + ((OpenBus = S9xGetByte(Addr + 2)) << 16) +
             ICPU.Registers.Y.W;
   else
      Addr = S9xGetWord(Addr) + (S9xGetByte(Addr + 2) << 16) + ICPU.Registers.Y.W;
   (*op)(Addr);
}

static void DirectIndexedIndirect(AccessMode a, InternalOp op)
{
   OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W + ICPU.Registers.X.W) & 0xffff;

   Addr = S9xGetWord(Addr);
   if (a & READ) OpenBus = (uint8_t)(Addr >> 8);
   Addr += ICPU.ShiftedDB;
   (*op)(Addr);
}

static void DirectIndexedX(AccessMode a, InternalOp op)
{
   if (a & READ) OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W + ICPU.Registers.X.W);
   Addr &= CheckEmulation() ? 0xff : 0xffff;

   (*op)(Addr);
}

static void DirectIndexedY(AccessMode a, InternalOp op)
{
   if (a & READ) OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W + ICPU.Registers.Y.W);
   Addr &= CheckEmulation() ? 0xff : 0xffff;
   (*op)(Addr);
}

static void AbsoluteIndexedX(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = ICPU.ShiftedDB + *(uint16_t*) CPU.PC + ICPU.Registers.X.W;
#else
   Addr = ICPU.ShiftedDB + *CPU.PC + (*(CPU.PC + 1) << 8) +
          ICPU.Registers.X.W;
#endif
   if (a & READ) OpenBus = *(CPU.PC + 1);
   CPU.PC += 2;
   // XXX: always add one cycle for ROL, LSR, etc
   // XXX: else is cross page boundary add one cycle
   (*op)(Addr);
}

static void AbsoluteIndexedY(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = ICPU.ShiftedDB + *(uint16_t*) CPU.PC + ICPU.Registers.Y.W;
#else
   Addr = ICPU.ShiftedDB + *CPU.PC + (*(CPU.PC + 1) << 8) +
          ICPU.Registers.Y.W;
#endif
   if (a & READ) OpenBus = *(CPU.PC + 1);
   CPU.PC += 2;
   // XXX: always add cycle for STA
   // XXX: else is cross page boundary add one cycle
   (*op)(Addr);
}

static void AbsoluteLongIndexedX(AccessMode a, InternalOp op)
{
   long Addr;
#ifdef FAST_LSB_WORD_ACCESS
   Addr = (*(uint32_t*) CPU.PC + ICPU.Registers.X.W) & 0xffffff;
#elif defined FAST_ALIGNED_LSB_WORD_ACCESS
   if (((intptr_t) CPU.PC & 1) == 0)
      Addr = ((*(uint16_t*) CPU.PC) + (*(CPU.PC + 2) << 16) + ICPU.Registers.X.W) &
             0xFFFFFF;
   else
      Addr = (*CPU.PC + ((*(uint16_t*)(CPU.PC + 1)) << 8) + ICPU.Registers.X.W) &
             0xFFFFFF;
#else
   Addr = (*CPU.PC + (*(CPU.PC + 1) << 8) + (*(CPU.PC + 2) << 16) +
           ICPU.Registers.X.W) & 0xffffff;
#endif
   if (a & READ) OpenBus = *(CPU.PC + 2);
   CPU.PC += 3;
   (*op)(Addr);
}

static void DirectIndirect(AccessMode a, InternalOp op)
{
   OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W) & 0xffff;
   Addr = S9xGetWord(Addr);
   if (a & READ) OpenBus = (uint8_t)(Addr >> 8);
   Addr += ICPU.ShiftedDB;
   (*op)(Addr);
}

static void DirectIndirectLong(AccessMode a, InternalOp op)
{
   OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.D.W) & 0xffff;
   if (a & READ)
      Addr = S9xGetWord(Addr) + ((OpenBus = S9xGetByte(Addr + 2)) << 16);
   else
      Addr = S9xGetWord(Addr) + (S9xGetByte(Addr + 2) << 16);
   (*op)(Addr);
}

static void StackRelative(AccessMode a, InternalOp op)
{
   if (a & READ) OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.S.W) & 0xffff;
   (*op)(Addr);
}

static void StackRelativeIndirectIndexed(AccessMode a, InternalOp op)
{
   OpenBus = *CPU.PC;
   long Addr = (*CPU.PC++ + ICPU.Registers.S.W) & 0xffff;
   Addr = S9xGetWord(Addr);
   if (a & READ) OpenBus = (uint8_t)(Addr >> 8);
   Addr = (Addr + ICPU.ShiftedDB +
           ICPU.Registers.Y.W) & 0xffffff;
   (*op)(Addr);
}
#endif