Idle skipping... maybe?

.gitignore

@@ -20,6 +20,7 @@ vgcore.*
 *.data
 disasm.txt
 *log*.txt
+*.log
 CMakeSettings.json
 compile_commands.json
 *.diagsession

src/backend/Core.cpp

@@ -110,6 +110,15 @@ void Core::Run(const float volumeL, const float volumeR) {
             }
 
             while (cycles < mem->mmio.vi.cyclesPerHalfline) {
+                if (IsAnythingSkippable()) {
+                    const u32 taken = Scheduler::GetInstance().events.top().time - Scheduler::GetInstance().ticks;
+                    cycles += taken;
+                    frameCycles += taken;
+                    Scheduler::GetInstance().Tick(taken);
+                    isReadingAnyIO = false;
+                    continue;
+                }
+
                 const u32 taken = StepCPU();
                 cycles += taken;
 
@@ -141,4 +150,9 @@ void Core::Run(const float volumeL, const float volumeR) {
     if (broken)
         pause = true;
 }
+
+bool Core::IsAnythingSkippable() {
+    MMIO &mmio = mem->mmio;
+    return (mmio.si.status.dmaBusy || mmio.pi.dmaBusy || mmio.pi.ioBusy) && isReadingAnyIO;
+}
 } // namespace n64

src/backend/Core.hpp

@@ -19,6 +19,8 @@ struct Core {
         return instance;
     }
 
+    static void SetIdleSkippingStatus(bool v) { GetInstance().isReadingAnyIO = v; }
+
     static Registers &GetRegs() { return GetInstance().regs; }
 
     static Mem &GetMem() { return *GetInstance().mem; }
@@ -57,5 +59,8 @@ struct Core {
 #endif
     Interpreter interpreter;
     ParallelRDP parallel;
+
+    bool isReadingAnyIO = false;
+    bool IsAnythingSkippable();
 };
 } // namespace n64

src/backend/core/mmio/PI.cpp

@@ -186,7 +186,8 @@ auto PI::BusRead<u16, false>(u32 addr) -> u16 {
             addr = (addr + 2) & ~3;
             const u32 index = HALF_ADDRESS(addr) - SREGION_PI_ROM;
             if (index > mem.rom.cart.size() - 1) {
-        panic("Address 0x{:08X} accessed an index {}/0x{:X} outside the bounds of the ROM!", addr, index, index);
+                panic("Address 0x{:08X} accessed an index {}/0x{:X} outside the bounds of the ROM!", addr, index,
+                      index);
             }
             return ircolib::ReadAccess<u16>(mem.rom.cart, index);
         }
@@ -260,7 +261,8 @@ auto PI::BusRead<u32, false>(u32 addr) -> u32 {
             if (index > mem.rom.cart.size() - 3) { // -3 because we're reading an entire word
                 switch (addr) {
                 case REGION_CART_ISVIEWER_BUFFER:
-          return std::byteswap<u32>(ircolib::ReadAccess<u32>(mem.isviewer, addr - SREGION_CART_ISVIEWER_BUFFER));
+                    return std::byteswap<u32>(
+                        ircolib::ReadAccess<u32>(mem.isviewer, addr - SREGION_CART_ISVIEWER_BUFFER));
                 case CART_ISVIEWER_FLUSH:
                     panic("Read from ISViewer flush!");
                 default:
@@ -367,7 +369,8 @@ auto PI::BusRead<u64, false>(u32 addr) -> u64 {
         {
             const u32 index = addr - SREGION_PI_ROM;
             if (index > mem.rom.cart.size() - 7) { // -7 because we're reading an entire dword
-        panic("Address 0x{:08X} accessed an index {}/0x{:X} outside the bounds of the ROM!", addr, index, index);
+                panic("Address 0x{:08X} accessed an index {}/0x{:X} outside the bounds of the ROM!", addr, index,
+                      index);
             }
             return ircolib::ReadAccess<u64>(mem.rom.cart, index);
         }
@@ -422,6 +425,7 @@ auto PI::Read(u32 addr) const -> u32 {
         return wrLen;
     case 0x04600010:
         {
+            Core::SetIdleSkippingStatus(true);
             u32 value = 0;
             value |= (dmaBusy << 0); // Is PI DMA active?
             value |= (ioBusy << 1); // Is PI IO busy?

src/backend/core/mmio/SI.cpp

@@ -24,6 +24,7 @@ auto SI::Read(u32 addr) const -> u32 {
         return 0;
     case 0x04800018:
         {
+            Core::SetIdleSkippingStatus(true);
             u32 val = 0;
             val |= status.dmaBusy;
             val |= (0 << 1);

src/backend/core/mmio/SI.hpp

@@ -4,8 +4,16 @@
 #include <core/mmio/PIF.hpp>
 
 namespace n64 {
+struct SI {
+    SI();
+    void Reset();
+    [[nodiscard]] auto Read(u32) const -> u32;
+    void Write(u32, u32);
+    template <bool toDram>
+    void DMA();
+    void DMA();
 
-union SIStatus {
+    union Status {
         u32 raw{};
         struct {
             unsigned dmaBusy : 1;
@@ -17,17 +25,8 @@ union SIStatus {
         };
     };
 
-struct SI {  
-  SI();
-  void Reset();
-  [[nodiscard]] auto Read(u32) const -> u32;
-  void Write(u32, u32);
-  template <bool toDram>
-  void DMA();
-  void DMA();
-  
     bool toDram = false;
-  SIStatus status{};
+    Status status{};
     u32 dramAddr{};
     u32 pifAddr{};
     PIF pif;