Annotation of hatari/src/cycles.c, revision 1.1.1.10

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) */
1.1.1.10! root      132:                /* We don't read the opcode if PC is located in the IO region (rare cases */
        !           133:                /* used in some games/demos protections) as this can create recursive calls */
        !           134:                /* (protection of the "Union Demo" runs at $ff8240) */
        !           135:                if ( ( ( BusErrorPC & 0xffffff ) < 0xff0000 ) || ( ( BusErrorPC & 0xffffff ) > 0xffffff ) )
        !           136:                        Opcode = get_word(BusErrorPC);                                  /* BusErrorPC points to the current opcode */
        !           137:                else
        !           138:                        Opcode = -1;
1.1.1.6   root      139:                //fprintf ( stderr , "opcode=%x\n" , Opcode );
                    140: 
                    141:                /* Assume we use 'move src,dst' : access cycle depends on dst mode */
                    142:                if ( Opcode == 0x11f8 )                         /* move.b xxx.w,xxx.w (eg MOVE.B $ffff8209.w,$26.w in Bird Mad Girl Show) */
1.1.1.9   root      143:                        AddCycles = CurrentInstrCycles + nWaitStateCycles - 8;          /* read is effective before the 8 write cycles for dst */
1.1.1.7   root      144:                else if ( OpcodeFamily == i_MVPRM )                                     /* eg movep.l d0,$ffc3(a1) in E605 (STE) */
1.1.1.9   root      145:                        AddCycles = 12 + MovepByteNbr * 4;                              /* [NP] FIXME, it works with E605 but gives 20-32 cycles instead of 16-28 */
1.1.1.7   root      146:                                                                                        /* something must be wrong in video.c */
1.1.1.6   root      147:                else
1.1.1.9   root      148:                        AddCycles = CurrentInstrCycles + nWaitStateCycles;              /* assume dest is reg : read is effective at the end of the instr */
1.1.1.4   root      149:        }
1.1       root      150: 
1.1.1.9   root      151:        return AddCycles;
1.1       root      152: }
                    153: 
                    154: 
1.1.1.9   root      155: 
1.1       root      156: /*-----------------------------------------------------------------------*/
1.1.1.2   root      157: /**
1.1.1.9   root      158:  * Compute the cycles where a write actually happens inside a specific
                    159:  * instruction type. We use some common cases, this should be handled more
                    160:  * accurately in the cpu emulation for each opcode.
1.1.1.2   root      161:  */
1.1.1.9   root      162: static int Cycles_GetInternalCycleOnWriteAccess(void)
1.1       root      163: {
1.1.1.9   root      164:        int AddCycles;
1.1       root      165: 
1.1.1.4   root      166:        if ( BusMode == BUS_MODE_BLITTER )
                    167:        {
1.1.1.9   root      168:                AddCycles = 4 + nWaitStateCycles;
1.1.1.4   root      169:        }
                    170:        else                                                    /* BUS_MODE_CPU */
                    171:        {
                    172:                /* TODO: Find proper cycles count depending on the type of the current instruction */
                    173:                /* (e.g. movem is not correctly handled) */
1.1.1.9   root      174:                AddCycles = CurrentInstrCycles + nWaitStateCycles;
1.1.1.4   root      175: 
1.1.1.10! root      176:                if ( ( OpcodeFamily == i_CLR ) || ( OpcodeFamily == i_NEG ) || ( OpcodeFamily == i_NEGX ) || ( OpcodeFamily == i_NOT ) )
        !           177:                        ;                                               /* Do nothing, the write is done during the last 4 cycles */
        !           178:                                                                        /* (e.g i_CLR for bottom border removal in No Scroll / Delirious Demo 4) */
        !           179: 
        !           180:                else if ( ( OpcodeFamily == i_ADD ) || ( OpcodeFamily == i_SUB ) )
        !           181:                        ;                                               /* Do nothing, the write is done during the last 4 cycles */
        !           182:                                                                        /* (eg 'add d1,(a0)' in rasters.prg by TOS Crew */
        !           183: 
        !           184:                else if ( ( OpcodeFamily == i_AND ) || ( OpcodeFamily == i_OR ) || ( OpcodeFamily == i_EOR ) )
1.1.1.7   root      185:                        ;                                               /* Do nothing, the write is done during the last 4 cycles */
1.1.1.8   root      186: 
                    187:                else if ( ( OpcodeFamily == i_BCHG ) || ( OpcodeFamily == i_BCLR ) || ( OpcodeFamily == i_BSET ) )
                    188:                        ;                                               /* Do nothing, the write is done during the last 4 cycles */
                    189: 
1.1.1.7   root      190:                else
                    191:                {
                    192:                        /* assume the behaviour of a 'move' (since this is the most */
                    193:                        /* common instr used when requiring cycle precise writes) */
1.1.1.9   root      194:                        if ( AddCycles >= 8 )
                    195:                                AddCycles -= 4;                 /* last 4 cycles are for prefetch */
1.1.1.7   root      196:                }
1.1.1.4   root      197:        }
1.1       root      198: 
1.1.1.9   root      199:        return AddCycles;
                    200: }
                    201: 
                    202: 
                    203: /*-----------------------------------------------------------------------*/
                    204: /**
                    205:  * Read a counter on CPU memory read access by taking care of the instruction
                    206:  * type (add the needed amount of additional cycles).
                    207:  */
                    208: int Cycles_GetCounterOnReadAccess(int nId)
                    209: {
                    210:        int AddCycles;
                    211: 
                    212:        AddCycles = Cycles_GetInternalCycleOnReadAccess();
                    213: 
                    214:        return Cycles_GetCounter(nId) + AddCycles;
                    215: }
                    216: 
                    217: 
                    218: /*-----------------------------------------------------------------------*/
                    219: /**
                    220:  * Read a counter on CPU memory write access by taking care of the instruction
                    221:  * type (add the needed amount of additional cycles).
                    222:  */
                    223: int Cycles_GetCounterOnWriteAccess(int nId)
                    224: {
                    225:        int AddCycles;
                    226: 
                    227:        AddCycles = Cycles_GetInternalCycleOnWriteAccess();
                    228: 
                    229:        return Cycles_GetCounter(nId) + AddCycles;
1.1       root      230: }
1.1.1.9   root      231: 
                    232: 
                    233: /*-----------------------------------------------------------------------*/
                    234: /**
                    235:  * Read the main clock counter on CPU memory read access by taking care of the instruction
                    236:  * type (add the needed amount of additional cycles).
                    237:  */
                    238: Uint64 Cycles_GetClockCounterOnReadAccess(void)
                    239: {
                    240:        int AddCycles;
                    241: 
                    242:        AddCycles = Cycles_GetInternalCycleOnReadAccess();
                    243: 
                    244:        return CyclesGlobalClockCounter + AddCycles;
                    245: }
                    246: 
                    247: 
                    248: /*-----------------------------------------------------------------------*/
                    249: /**
                    250:  * Read the main clock counter on CPU memory write access by taking care of the instruction
                    251:  * type (add the needed amount of additional cycles).
                    252:  */
                    253: Uint64 Cycles_GetClockCounterOnWriteAccess(void)
                    254: {
                    255:        int AddCycles;
                    256: 
                    257:        AddCycles = Cycles_GetInternalCycleOnWriteAccess();
                    258: 
                    259:        return CyclesGlobalClockCounter + AddCycles;
                    260: }
                    261: 
                    262: 
                    263: 

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