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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: {
130: /* TODO: Find proper cycles count depending on the type of the current instruction */
131: /* (e.g. movem is not correctly handled) */
1.1.1.6 root 132: Opcode = get_word(BusErrorPC);
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 */
1.1.1.6 root 141: else
1.1.1.9 ! root 142: AddCycles = CurrentInstrCycles + nWaitStateCycles; /* assume dest is reg : read is effective at the end of the instr */
1.1.1.4 root 143: }
1.1 root 144:
1.1.1.9 ! root 145: return AddCycles;
1.1 root 146: }
147:
148:
1.1.1.9 ! root 149:
1.1 root 150: /*-----------------------------------------------------------------------*/
1.1.1.2 root 151: /**
1.1.1.9 ! root 152: * Compute the cycles where a write actually happens inside a specific
! 153: * instruction type. We use some common cases, this should be handled more
! 154: * accurately in the cpu emulation for each opcode.
1.1.1.2 root 155: */
1.1.1.9 ! root 156: static int Cycles_GetInternalCycleOnWriteAccess(void)
1.1 root 157: {
1.1.1.9 ! root 158: int AddCycles;
1.1 root 159:
1.1.1.4 root 160: if ( BusMode == BUS_MODE_BLITTER )
161: {
1.1.1.9 ! root 162: AddCycles = 4 + nWaitStateCycles;
1.1.1.4 root 163: }
164: else /* BUS_MODE_CPU */
165: {
166: /* TODO: Find proper cycles count depending on the type of the current instruction */
167: /* (e.g. movem is not correctly handled) */
1.1.1.9 ! root 168: AddCycles = CurrentInstrCycles + nWaitStateCycles;
1.1.1.4 root 169:
1.1.1.7 root 170: if ( OpcodeFamily == i_CLR ) /* should also be the case for add, sub, and, or, eor, neg, not */
171: ; /* Do nothing, the write is done during the last 4 cycles */
172: /* (e.g bottom border removal in No Scroll / Delirious Demo 4) */
1.1.1.8 root 173:
174: else if ( ( OpcodeFamily == i_BCHG ) || ( OpcodeFamily == i_BCLR ) || ( OpcodeFamily == i_BSET ) )
175: ; /* Do nothing, the write is done during the last 4 cycles */
176:
1.1.1.7 root 177: else
178: {
179: /* assume the behaviour of a 'move' (since this is the most */
180: /* common instr used when requiring cycle precise writes) */
1.1.1.9 ! root 181: if ( AddCycles >= 8 )
! 182: AddCycles -= 4; /* last 4 cycles are for prefetch */
1.1.1.7 root 183: }
1.1.1.4 root 184: }
1.1 root 185:
1.1.1.9 ! root 186: return AddCycles;
! 187: }
! 188:
! 189:
! 190: /*-----------------------------------------------------------------------*/
! 191: /**
! 192: * Read a counter on CPU memory read access by taking care of the instruction
! 193: * type (add the needed amount of additional cycles).
! 194: */
! 195: int Cycles_GetCounterOnReadAccess(int nId)
! 196: {
! 197: int AddCycles;
! 198:
! 199: AddCycles = Cycles_GetInternalCycleOnReadAccess();
! 200:
! 201: return Cycles_GetCounter(nId) + AddCycles;
! 202: }
! 203:
! 204:
! 205: /*-----------------------------------------------------------------------*/
! 206: /**
! 207: * Read a counter on CPU memory write access by taking care of the instruction
! 208: * type (add the needed amount of additional cycles).
! 209: */
! 210: int Cycles_GetCounterOnWriteAccess(int nId)
! 211: {
! 212: int AddCycles;
! 213:
! 214: AddCycles = Cycles_GetInternalCycleOnWriteAccess();
! 215:
! 216: return Cycles_GetCounter(nId) + AddCycles;
1.1 root 217: }
1.1.1.9 ! root 218:
! 219:
! 220: /*-----------------------------------------------------------------------*/
! 221: /**
! 222: * Read the main clock counter on CPU memory read access by taking care of the instruction
! 223: * type (add the needed amount of additional cycles).
! 224: */
! 225: Uint64 Cycles_GetClockCounterOnReadAccess(void)
! 226: {
! 227: int AddCycles;
! 228:
! 229: AddCycles = Cycles_GetInternalCycleOnReadAccess();
! 230:
! 231: return CyclesGlobalClockCounter + AddCycles;
! 232: }
! 233:
! 234:
! 235: /*-----------------------------------------------------------------------*/
! 236: /**
! 237: * Read the main clock counter on CPU memory write access by taking care of the instruction
! 238: * type (add the needed amount of additional cycles).
! 239: */
! 240: Uint64 Cycles_GetClockCounterOnWriteAccess(void)
! 241: {
! 242: int AddCycles;
! 243:
! 244: AddCycles = Cycles_GetInternalCycleOnWriteAccess();
! 245:
! 246: return CyclesGlobalClockCounter + AddCycles;
! 247: }
! 248:
! 249:
! 250:
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