'_cycles' pseudo register added (returns cycles of last instruction)

src/debugger/Debugger.cxx

@@ -802,6 +802,7 @@ Debugger::BuiltinFunction Debugger::ourBuiltinFunctions[NUM_BUILTIN_FUNCS] = {
 Debugger::PseudoRegister Debugger::ourPseudoRegisters[NUM_PSEUDO_REGS] = {
   { "_bank",      "Currently selected bank" },
   { "_cclocks",   "Color clocks on current scanline" },
+  { "_cycles",    "Number of cycles of last instruction" },
   { "_cycleshi",  "Higher 32 bits of number of cycles since emulation started" },
   { "_cycleslo",  "Lower 32 bits of number of cycles since emulation started" },
   { "_fcount",    "Number of frames since emulation started" },

src/debugger/Debugger.hxx

@@ -315,7 +315,7 @@ class Debugger : public DialogContainer
       string name, help;
     };
     static const uInt32 NUM_BUILTIN_FUNCS = 18;
-    static const uInt32 NUM_PSEUDO_REGS = 11;
+    static const uInt32 NUM_PSEUDO_REGS = 12;
     static BuiltinFunction ourBuiltinFunctions[NUM_BUILTIN_FUNCS];
     static PseudoRegister ourPseudoRegisters[NUM_PSEUDO_REGS];
 

src/emucore/M6502.cxx

@@ -52,6 +52,7 @@ M6502::M6502(const Settings& settings)
     mySettings(settings),
     A(0), X(0), Y(0), SP(0), IR(0), PC(0),
     N(false), V(false), B(false), D(false), I(false), notZ(false), C(false),
+    cycles(0),
     myNumberOfDistinctAccesses(0),
     myLastAddress(0),
     myLastPeekAddress(0),
@@ -99,6 +100,8 @@ void M6502::reset()
   PS(BSPF::containsIgnoreCase(cpurandom, "P") ?
           mySystem->randGenerator().next() : 0x20);
 
+  cycles = 0;
+
   // Load PC from the reset vector
   PC = uInt16(mySystem->peek(0xfffc)) | (uInt16(mySystem->peek(0xfffd)) << 8);
 
@@ -124,6 +127,7 @@ inline uInt8 M6502::peek(uInt16 address, uInt8 flags)
   }
   ////////////////////////////////////////////////
   mySystem->incrementCycles(SYSTEM_CYCLES_PER_CPU);
+  cycles += SYSTEM_CYCLES_PER_CPU;
   uInt8 result = mySystem->peek(address, flags);
   myLastPeekAddress = address;
 
@@ -157,6 +161,7 @@ inline void M6502::poke(uInt16 address, uInt8 value, uInt8 flags)
   }
   ////////////////////////////////////////////////
   mySystem->incrementCycles(SYSTEM_CYCLES_PER_CPU);
+  cycles += SYSTEM_CYCLES_PER_CPU;
   mySystem->poke(address, value, flags);
   myLastPokeAddress = address;
 
@@ -238,6 +243,7 @@ bool M6502::execute(uInt32 number)
       // Reset the peek/poke address pointers
       myLastPeekAddress = myLastPokeAddress = myDataAddressForPoke = 0;
 
+      cycles = 0;
       // Fetch instruction at the program counter
       IR = peek(PC++, DISASM_CODE);  // This address represents a code section
 
@@ -251,6 +257,7 @@ bool M6502::execute(uInt32 number)
           // Oops, illegal instruction executed so set fatal error flag
           myExecutionStatus |= FatalErrorBit;
       }
+      //cycles = mySystem->cycles() - c0;
     }
 
     // See if we need to handle an interrupt

src/emucore/M6502.hxx

@@ -348,6 +348,8 @@ class M6502 : public Serializable
     bool notZ;  // Z flag complement for processor status register
     bool C;     // C flag for processor status register
 
+    uInt8 cycles; // cycles of last instruction
+
     /// Indicates the numer of distinct memory accesses
     uInt32 myNumberOfDistinctAccesses;
 

src/yacc/YaccParser.cxx

@@ -219,6 +219,8 @@ CpuMethod getCpuSpecial(char* ch)
     return &CpuDebug::i;
   else if(BSPF::equalsIgnoreCase(ch, "b"))
     return &CpuDebug::b;
+  else if(BSPF::equalsIgnoreCase(ch, "_cycles"))
+    return &CpuDebug::cycles;
   else
     return nullptr;
 }