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1.1 root 1: /*
2: Hatari - cycles.c
3:
1.1.1.9 root 4: This file is distributed under the GNU General Public License, version 2
5: or at your option any later version. Read the file gpl.txt for details.
1.1 root 6:
7: Here we take care of cycle counters. For performance reasons we don't increase
8: all counters after each 68k instruction, but only one main counter.
9: When we need to read one of the normal counters (currently only for video
10: and sound cycles), we simply update these counters with the main counter
11: before returning the current counter value.
12: */
1.1.1.2 root 13:
14:
15: /* 2007/03/xx [NP] Use 'CurrentInstrCycles' to get a good approximation for */
16: /* Cycles_GetCounterOnReadAccess and Cycles_GetCounterOnWriteAccess*/
17: /* (this should work correctly with 'move' instruction). */
1.1.1.3 root 18: /* 2008/04/14 [NP] Take nWaitStateCycles into account when computing the value of */
19: /* Cycles_GetCounterOnReadAccess and Cycles_GetCounterOnWriteAccess*/
1.1.1.4 root 20: /* 2008/12/21 [NP] Use BusMode to adjust Cycles_GetCounterOnReadAccess and */
21: /* Cycles_GetCounterOnWriteAccess depending on who is owning the */
22: /* bus (cpu, blitter). */
1.1.1.6 root 23: /* 2011/03/26 [NP] In Cycles_GetCounterOnReadAccess, add a special case for opcode */
24: /* $11f8 'move.b xxx.w,xxx.w' (fix MOVE.B $ffff8209.w,$26.w in */
25: /* 'Bird Mad Girl Show' demo's loader/protection) */
1.1.1.9 root 26: /* 2012/08/19 [NP] Add a global counter CyclesGlobalClockCounter to count cycles */
27: /* since the last reset. */
1.1.1.2 root 28:
29:
1.1.1.4 root 30: const char Cycles_fileid[] = "Hatari cycles.c : " __DATE__ " " __TIME__;
1.1 root 31:
32: #include "main.h"
1.1.1.3 root 33: #include "m68000.h"
1.1.1.5 root 34: #include "memorySnapShot.h"
1.1 root 35: #include "cycles.h"
36:
37:
1.1.1.9 root 38: int nCyclesMainCounter; /* Main cycles counter since previous Cycles_UpdateCounters() */
1.1 root 39:
1.1.1.5 root 40: static int nCyclesCounter[CYCLES_COUNTER_MAX]; /* Array with all counters */
1.1 root 41:
1.1.1.9 root 42: Uint64 CyclesGlobalClockCounter = 0; /* Global clock counter since starting Hatari (it's never reset afterwards) */
1.1.1.7 root 43:
1.1.1.9 root 44: int CurrentInstrCycles;
45: int MovepByteNbr = 0; /* Number of the byte currently transferred in a movep (1..2 or 1..4) */
46: /* 0 means current instruction is not a movep */
47:
48:
49: static void Cycles_UpdateCounters(void);
50: static int Cycles_GetInternalCycleOnReadAccess(void);
51: static int Cycles_GetInternalCycleOnWriteAccess(void);
1.1.1.2 root 52:
1.1 root 53:
1.1.1.5 root 54:
55: /*-----------------------------------------------------------------------*/
56: /**
57: * Save/Restore snapshot of local variables ('MemorySnapShot_Store' handles type)
58: */
59: void Cycles_MemorySnapShot_Capture(bool bSave)
60: {
61: /* Save/Restore details */
62: MemorySnapShot_Store(&nCyclesMainCounter, sizeof(nCyclesMainCounter));
63: MemorySnapShot_Store(nCyclesCounter, sizeof(nCyclesCounter));
1.1.1.9 root 64: MemorySnapShot_Store(&CyclesGlobalClockCounter, sizeof(CyclesGlobalClockCounter));
1.1.1.5 root 65: MemorySnapShot_Store(&CurrentInstrCycles, sizeof(CurrentInstrCycles));
66: }
67:
68:
1.1 root 69: /*-----------------------------------------------------------------------*/
1.1.1.2 root 70: /**
71: * Update all cycles counters with the current value of nCyclesMainCounter.
72: */
1.1 root 73: static void Cycles_UpdateCounters(void)
74: {
75: int i;
76:
77: for (i = 0; i < CYCLES_COUNTER_MAX; i++)
78: {
79: nCyclesCounter[i] += nCyclesMainCounter;
80: }
81:
82: nCyclesMainCounter = 0;
83: }
84:
85:
86: /*-----------------------------------------------------------------------*/
1.1.1.2 root 87: /**
88: * Set a counter to a new value.
89: */
1.1 root 90: void Cycles_SetCounter(int nId, int nValue)
91: {
92: /* Update counters first (nCyclesMainCounter must be 0 afterwards) */
93: Cycles_UpdateCounters();
94:
95: /* Now set the new value: */
96: nCyclesCounter[nId] = nValue;
97: }
98:
99:
100: /*-----------------------------------------------------------------------*/
1.1.1.2 root 101: /**
102: * Read a counter.
103: */
1.1 root 104: int Cycles_GetCounter(int nId)
105: {
106: /* Update counters first so we read an up-to-date value */
107: Cycles_UpdateCounters();
108:
109: return nCyclesCounter[nId];
110: }
111:
112:
113: /*-----------------------------------------------------------------------*/
1.1.1.2 root 114: /**
1.1.1.9 root 115: * Compute the cycles where a read actually happens inside a specific
116: * instruction type. We use some common cases, this should be handled more
117: * accurately in the cpu emulation for each opcode.
1.1.1.2 root 118: */
1.1.1.9 root 119: static int Cycles_GetInternalCycleOnReadAccess(void)
1.1 root 120: {
1.1.1.9 root 121: int AddCycles;
1.1.1.6 root 122: int Opcode;
1.1 root 123:
1.1.1.4 root 124: if ( BusMode == BUS_MODE_BLITTER )
125: {
1.1.1.9 root 126: AddCycles = 4 + nWaitStateCycles;
1.1.1.4 root 127: }
128: else /* BUS_MODE_CPU */
129: {
1.1.1.11! root 130: /* TODO: Find proper cycles count depending on the opcode/family of the current instruction */
1.1.1.4 root 131: /* (e.g. movem is not correctly handled) */
1.1.1.11! root 132: Opcode = M68000_CurrentOpcode;
1.1.1.6 root 133: //fprintf ( stderr , "opcode=%x\n" , Opcode );
134:
135: /* Assume we use 'move src,dst' : access cycle depends on dst mode */
136: if ( Opcode == 0x11f8 ) /* move.b xxx.w,xxx.w (eg MOVE.B $ffff8209.w,$26.w in Bird Mad Girl Show) */
1.1.1.9 root 137: AddCycles = CurrentInstrCycles + nWaitStateCycles - 8; /* read is effective before the 8 write cycles for dst */
1.1.1.7 root 138: else if ( OpcodeFamily == i_MVPRM ) /* eg movep.l d0,$ffc3(a1) in E605 (STE) */
1.1.1.9 root 139: AddCycles = 12 + MovepByteNbr * 4; /* [NP] FIXME, it works with E605 but gives 20-32 cycles instead of 16-28 */
1.1.1.7 root 140: /* something must be wrong in video.c */
1.1.1.11! root 141: /* FIXME : this should be : AddCycles = 4 + MovepByteNbr * 4, but this breaks e605 in video.c */
1.1.1.6 root 142: else
1.1.1.9 root 143: AddCycles = CurrentInstrCycles + nWaitStateCycles; /* assume dest is reg : read is effective at the end of the instr */
1.1.1.4 root 144: }
1.1 root 145:
1.1.1.9 root 146: return AddCycles;
1.1 root 147: }
148:
149:
1.1.1.9 root 150:
1.1 root 151: /*-----------------------------------------------------------------------*/
1.1.1.2 root 152: /**
1.1.1.9 root 153: * Compute the cycles where a write actually happens inside a specific
154: * instruction type. We use some common cases, this should be handled more
155: * accurately in the cpu emulation for each opcode.
1.1.1.2 root 156: */
1.1.1.9 root 157: static int Cycles_GetInternalCycleOnWriteAccess(void)
1.1 root 158: {
1.1.1.9 root 159: int AddCycles;
1.1 root 160:
1.1.1.4 root 161: if ( BusMode == BUS_MODE_BLITTER )
162: {
1.1.1.9 root 163: AddCycles = 4 + nWaitStateCycles;
1.1.1.4 root 164: }
165: else /* BUS_MODE_CPU */
166: {
167: /* TODO: Find proper cycles count depending on the type of the current instruction */
168: /* (e.g. movem is not correctly handled) */
1.1.1.9 root 169: AddCycles = CurrentInstrCycles + nWaitStateCycles;
1.1.1.4 root 170:
1.1.1.10 root 171: if ( ( OpcodeFamily == i_CLR ) || ( OpcodeFamily == i_NEG ) || ( OpcodeFamily == i_NEGX ) || ( OpcodeFamily == i_NOT ) )
172: ; /* Do nothing, the write is done during the last 4 cycles */
173: /* (e.g i_CLR for bottom border removal in No Scroll / Delirious Demo 4) */
174:
175: else if ( ( OpcodeFamily == i_ADD ) || ( OpcodeFamily == i_SUB ) )
176: ; /* Do nothing, the write is done during the last 4 cycles */
177: /* (eg 'add d1,(a0)' in rasters.prg by TOS Crew */
178:
179: else if ( ( OpcodeFamily == i_AND ) || ( OpcodeFamily == i_OR ) || ( OpcodeFamily == i_EOR ) )
1.1.1.7 root 180: ; /* Do nothing, the write is done during the last 4 cycles */
1.1.1.8 root 181:
182: else if ( ( OpcodeFamily == i_BCHG ) || ( OpcodeFamily == i_BCLR ) || ( OpcodeFamily == i_BSET ) )
183: ; /* Do nothing, the write is done during the last 4 cycles */
184:
1.1.1.7 root 185: else
186: {
187: /* assume the behaviour of a 'move' (since this is the most */
188: /* common instr used when requiring cycle precise writes) */
1.1.1.9 root 189: if ( AddCycles >= 8 )
190: AddCycles -= 4; /* last 4 cycles are for prefetch */
1.1.1.7 root 191: }
1.1.1.4 root 192: }
1.1 root 193:
1.1.1.9 root 194: return AddCycles;
195: }
196:
197:
198: /*-----------------------------------------------------------------------*/
199: /**
200: * Read a counter on CPU memory read access by taking care of the instruction
201: * type (add the needed amount of additional cycles).
202: */
203: int Cycles_GetCounterOnReadAccess(int nId)
204: {
205: int AddCycles;
206:
207: AddCycles = Cycles_GetInternalCycleOnReadAccess();
208:
209: return Cycles_GetCounter(nId) + AddCycles;
210: }
211:
212:
213: /*-----------------------------------------------------------------------*/
214: /**
215: * Read a counter on CPU memory write access by taking care of the instruction
216: * type (add the needed amount of additional cycles).
217: */
218: int Cycles_GetCounterOnWriteAccess(int nId)
219: {
220: int AddCycles;
221:
222: AddCycles = Cycles_GetInternalCycleOnWriteAccess();
223:
224: return Cycles_GetCounter(nId) + AddCycles;
1.1 root 225: }
1.1.1.9 root 226:
227:
228: /*-----------------------------------------------------------------------*/
229: /**
230: * Read the main clock counter on CPU memory read access by taking care of the instruction
231: * type (add the needed amount of additional cycles).
232: */
233: Uint64 Cycles_GetClockCounterOnReadAccess(void)
234: {
235: int AddCycles;
236:
237: AddCycles = Cycles_GetInternalCycleOnReadAccess();
238:
239: return CyclesGlobalClockCounter + AddCycles;
240: }
241:
242:
243: /*-----------------------------------------------------------------------*/
244: /**
245: * Read the main clock counter on CPU memory write access by taking care of the instruction
246: * type (add the needed amount of additional cycles).
247: */
248: Uint64 Cycles_GetClockCounterOnWriteAccess(void)
249: {
250: int AddCycles;
251:
252: AddCycles = Cycles_GetInternalCycleOnWriteAccess();
253:
254: return CyclesGlobalClockCounter + AddCycles;
255: }
256:
257:
258:
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