CPU: Use lookup tables for memory access

src/core/bus.h

@@ -23,9 +23,12 @@ enum : u32
   RAM_8MB_SIZE = 0x800000,
   RAM_8MB_MASK = RAM_8MB_SIZE - 1,
   RAM_MIRROR_END = 0x800000,
+  RAM_MIRROR_SIZE = 0x800000,
   EXP1_BASE = 0x1F000000,
   EXP1_SIZE = 0x800000,
   EXP1_MASK = EXP1_SIZE - 1,
+  HW_BASE = 0x1F801000,
+  HW_SIZE = 0x1000,
   MEMCTRL_BASE = 0x1F801000,
   MEMCTRL_SIZE = 0x40,
   MEMCTRL_MASK = MEMCTRL_SIZE - 1,
@@ -38,9 +41,9 @@ enum : u32
   MEMCTRL2_BASE = 0x1F801060,
   MEMCTRL2_SIZE = 0x10,
   MEMCTRL2_MASK = MEMCTRL2_SIZE - 1,
-  INTERRUPT_CONTROLLER_BASE = 0x1F801070,
-  INTERRUPT_CONTROLLER_SIZE = 0x10,
-  INTERRUPT_CONTROLLER_MASK = INTERRUPT_CONTROLLER_SIZE - 1,
+  INTC_BASE = 0x1F801070,
+  INTC_SIZE = 0x10,
+  INTERRUPT_CONTROLLER_MASK = INTC_SIZE - 1,
   DMA_BASE = 0x1F801080,
   DMA_SIZE = 0x80,
   DMA_MASK = DMA_SIZE - 1,
@@ -63,7 +66,7 @@ enum : u32
   EXP2_SIZE = 0x2000,
   EXP2_MASK = EXP2_SIZE - 1,
   EXP3_BASE = 0x1FA00000,
-  EXP3_SIZE = 0x1,
+  EXP3_SIZE = 0x200000,
   EXP3_MASK = EXP3_SIZE - 1,
   BIOS_BASE = 0x1FC00000,
   BIOS_SIZE = 0x80000,
@@ -85,6 +88,11 @@ enum : u32
   RAM_2MB_CODE_PAGE_COUNT = (RAM_2MB_SIZE + (HOST_PAGE_SIZE + 1)) / HOST_PAGE_SIZE,
   RAM_8MB_CODE_PAGE_COUNT = (RAM_8MB_SIZE + (HOST_PAGE_SIZE + 1)) / HOST_PAGE_SIZE,
 
+  MEMORY_LUT_PAGE_SIZE = 4096,
+  MEMORY_LUT_PAGE_SHIFT = 12,
+  MEMORY_LUT_SIZE = 0x100000,                 // 0x100000000 >> 12
+  MEMORY_LUT_SLOTS = MEMORY_LUT_SIZE * 3 * 2, // [size][read_write]
+
   FASTMEM_LUT_PAGE_SIZE = 4096,
   FASTMEM_LUT_PAGE_MASK = FASTMEM_LUT_PAGE_SIZE - 1,
   FASTMEM_LUT_PAGE_SHIFT = 12,
@@ -105,8 +113,20 @@ void Shutdown();
 void Reset();
 bool DoState(StateWrapper& sw);
 
+using MemoryReadHandler = u32 (*)(VirtualMemoryAddress address);
+using MemoryWriteHandler = void (*)(VirtualMemoryAddress, u32);
+
+void** GetMemoryHandlers(bool isolate_cache, bool swap_caches);
+
+template<typename FP>
+ALWAYS_INLINE_RELEASE static FP* OffsetHandlerArray(void** handlers, MemoryAccessSize size, MemoryAccessType type)
+{
+  return reinterpret_cast<FP*>(handlers +
+                               (((static_cast<size_t>(size) * 2) + static_cast<size_t>(type)) * MEMORY_LUT_SIZE));
+}
+
 CPUFastmemMode GetFastmemMode();
-u8* GetFastmemBase();
+void* GetFastmemBase();
 void UpdateFastmemViews(CPUFastmemMode mode);
 bool CanUseFastmemForAddress(VirtualMemoryAddress address);
 
@@ -116,7 +136,12 @@ extern std::bitset<RAM_8MB_CODE_PAGE_COUNT> g_ram_code_bits;
 extern u8* g_ram;      // 2MB-8MB RAM
 extern u32 g_ram_size; // Active size of RAM.
 extern u32 g_ram_mask; // Active address bits for RAM.
-extern u8 g_bios[BIOS_SIZE]; // 512K BIOS ROM
+extern u8* g_bios;     // 512K BIOS ROM
+extern std::array<TickCount, 3> g_exp1_access_time;
+extern std::array<TickCount, 3> g_exp2_access_time;
+extern std::array<TickCount, 3> g_bios_access_time;
+extern std::array<TickCount, 3> g_cdrom_access_time;
+extern std::array<TickCount, 3> g_spu_access_time;
 
 /// Returns true if the address specified is writable (RAM).
 ALWAYS_INLINE static bool IsRAMAddress(PhysicalMemoryAddress address)

src/core/cpu_code_cache.cpp

@@ -265,7 +265,6 @@ void Initialize()
 
   AllocateFastMap();
 
-
 #ifdef ENABLE_RECOMPILER
   if (g_settings.IsUsingRecompiler())
   {
@@ -531,7 +530,9 @@ void Flush()
 }
 
 #ifndef _MSC_VER
-void __debugbreak() {}
+void __debugbreak()
+{
+}
 #endif
 
 void LogCurrentState()
@@ -1127,7 +1128,7 @@ bool InitializeFastmem()
   }
 
   Bus::UpdateFastmemViews(mode);
-  CPU::UpdateFastmemBase();
+  CPU::UpdateMemoryPointers();
   return true;
 }
 
@@ -1135,21 +1136,22 @@ void ShutdownFastmem()
 {
   Common::PageFaultHandler::RemoveHandler(&s_host_code_map);
   Bus::UpdateFastmemViews(CPUFastmemMode::Disabled);
-  CPU::UpdateFastmemBase();
+  CPU::UpdateMemoryPointers();
 }
 
 #ifdef ENABLE_MMAP_FASTMEM
 
 Common::PageFaultHandler::HandlerResult MMapPageFaultHandler(void* exception_pc, void* fault_address, bool is_write)
 {
-  if (static_cast<u8*>(fault_address) < g_state.fastmem_base ||
-      (static_cast<u8*>(fault_address) - g_state.fastmem_base) >= static_cast<ptrdiff_t>(Bus::FASTMEM_ARENA_SIZE))
+  if (static_cast<u8*>(fault_address) < static_cast<u8*>(g_state.fastmem_base) ||
+      (static_cast<u8*>(fault_address) - static_cast<u8*>(g_state.fastmem_base)) >=
+        static_cast<ptrdiff_t>(Bus::FASTMEM_ARENA_SIZE))
   {
     return Common::PageFaultHandler::HandlerResult::ExecuteNextHandler;
   }
 
-  const PhysicalMemoryAddress fastmem_address =
-    static_cast<PhysicalMemoryAddress>(static_cast<ptrdiff_t>(static_cast<u8*>(fault_address) - g_state.fastmem_base));
+  const PhysicalMemoryAddress fastmem_address = static_cast<PhysicalMemoryAddress>(
+    static_cast<ptrdiff_t>(static_cast<u8*>(fault_address) - static_cast<u8*>(g_state.fastmem_base)));
 
   Log_DevPrintf("Page fault handler invoked at PC=%p Address=%p %s, fastmem offset 0x%08X", exception_pc, fault_address,
                 is_write ? "(write)" : "(read)", fastmem_address);

src/core/cpu_core.cpp

@@ -63,6 +63,21 @@ static void ExecuteInstruction();
 template<PGXPMode pgxp_mode, bool debug>
 [[noreturn]] static void ExecuteImpl();
 
+static bool FetchInstruction();
+static bool FetchInstructionForInterpreterFallback();
+template<bool add_ticks, bool icache_read = false, u32 word_count = 1, bool raise_exceptions>
+static bool DoInstructionRead(PhysicalMemoryAddress address, void* data);
+template<MemoryAccessType type, MemoryAccessSize size>
+static bool DoSafeMemoryAccess(VirtualMemoryAddress address, u32& value);
+template<MemoryAccessType type, MemoryAccessSize size>
+static bool DoAlignmentCheck(VirtualMemoryAddress address);
+static bool ReadMemoryByte(VirtualMemoryAddress addr, u8* value);
+static bool ReadMemoryHalfWord(VirtualMemoryAddress addr, u16* value);
+static bool ReadMemoryWord(VirtualMemoryAddress addr, u32* value);
+static bool WriteMemoryByte(VirtualMemoryAddress addr, u32 value);
+static bool WriteMemoryHalfWord(VirtualMemoryAddress addr, u32 value);
+static bool WriteMemoryWord(VirtualMemoryAddress addr, u32 value);
+
 State g_state;
 bool TRACE_EXECUTION = false;
 
@@ -139,7 +154,7 @@ void CPU::Initialize()
   s_last_breakpoint_check_pc = INVALID_BREAKPOINT_PC;
   s_single_step = false;
 
-  UpdateFastmemBase();
+  UpdateMemoryPointers();
 
   GTE::Initialize();
 }
@@ -154,6 +169,8 @@ void CPU::Reset()
 {
   g_state.pending_ticks = 0;
   g_state.downcount = 0;
+  g_state.exception_raised = false;
+  g_state.bus_error = false;
 
   g_state.regs = {};
 
@@ -168,7 +185,7 @@ void CPU::Reset()
   g_state.cop0_regs.cause.bits = 0;
 
   ClearICache();
-  UpdateFastmemBase();
+  UpdateMemoryPointers();
 
   GTE::Reset();
 
@@ -202,6 +219,7 @@ bool CPU::DoState(StateWrapper& sw)
   sw.Do(&g_state.next_instruction_is_branch_delay_slot);
   sw.Do(&g_state.branch_was_taken);
   sw.Do(&g_state.exception_raised);
+  sw.DoEx(&g_state.bus_error, 61, false);
   if (sw.GetVersion() < 59)
   {
     bool interrupt_delay;
@@ -240,21 +258,13 @@ bool CPU::DoState(StateWrapper& sw)
 
   if (sw.IsReading())
   {
-    UpdateFastmemBase();
+    UpdateMemoryPointers();
     g_state.gte_completion_tick = 0;
   }
 
   return !sw.HasError();
 }
 
-void CPU::UpdateFastmemBase()
-{
-  if (g_state.cop0_regs.sr.Isc)
-    g_state.fastmem_base = nullptr;
-  else
-    g_state.fastmem_base = Bus::GetFastmemBase();
-}
-
 ALWAYS_INLINE_RELEASE void CPU::SetPC(u32 new_pc)
 {
   DebugAssert(Common::IsAlignedPow2(new_pc, 4));
@@ -527,6 +537,7 @@ ALWAYS_INLINE_RELEASE void CPU::WriteCop0Reg(Cop0Reg reg, u32 value)
       g_state.cop0_regs.sr.bits =
         (g_state.cop0_regs.sr.bits & ~Cop0Registers::SR::WRITE_MASK) | (value & Cop0Registers::SR::WRITE_MASK);
       Log_DebugPrintf("COP0 SR <- %08X (now %08X)", value, g_state.cop0_regs.sr.bits);
+      UpdateMemoryPointers();
       CheckForPendingInterrupt();
     }
     break;
@@ -2357,3 +2368,904 @@ bool CPU::Recompiler::Thunks::InterpretInstructionPGXP()
   ExecuteInstruction<PGXPMode::Memory, false>();
   return g_state.exception_raised;
 }
+
+ALWAYS_INLINE_RELEASE Bus::MemoryReadHandler CPU::GetMemoryReadHandler(VirtualMemoryAddress address,
+                                                                       MemoryAccessSize size)
+{
+  Bus::MemoryReadHandler* base =
+    Bus::OffsetHandlerArray<Bus::MemoryReadHandler>(g_state.memory_handlers, size, MemoryAccessType::Read);
+  return base[address >> Bus::MEMORY_LUT_PAGE_SHIFT];
+}
+
+ALWAYS_INLINE_RELEASE Bus::MemoryWriteHandler CPU::GetMemoryWriteHandler(VirtualMemoryAddress address,
+                                                                         MemoryAccessSize size)
+{
+  Bus::MemoryWriteHandler* base =
+    Bus::OffsetHandlerArray<Bus::MemoryWriteHandler>(g_state.memory_handlers, size, MemoryAccessType::Write);
+  return base[address >> Bus::MEMORY_LUT_PAGE_SHIFT];
+}
+
+void CPU::UpdateMemoryPointers()
+{
+  g_state.memory_handlers = Bus::GetMemoryHandlers(g_state.cop0_regs.sr.Isc, g_state.cop0_regs.sr.Swc);
+  g_state.fastmem_base = g_state.cop0_regs.sr.Isc ? nullptr : Bus::GetFastmemBase();
+}
+
+void CPU::ExecutionModeChanged()
+{
+  g_state.bus_error = false;
+}
+
+template<bool add_ticks, bool icache_read, u32 word_count, bool raise_exceptions>
+ALWAYS_INLINE_RELEASE bool CPU::DoInstructionRead(PhysicalMemoryAddress address, void* data)
+{
+  using namespace Bus;
+
+  address &= PHYSICAL_MEMORY_ADDRESS_MASK;
+
+  if (address < RAM_MIRROR_END)
+  {
+    std::memcpy(data, &g_ram[address & g_ram_mask], sizeof(u32) * word_count);
+    if constexpr (add_ticks)
+      g_state.pending_ticks += (icache_read ? 1 : RAM_READ_TICKS) * word_count;
+
+    return true;
+  }
+  else if (address >= BIOS_BASE && address < (BIOS_BASE + BIOS_SIZE))
+  {
+    std::memcpy(data, &g_bios[(address - BIOS_BASE) & BIOS_MASK], sizeof(u32) * word_count);
+    if constexpr (add_ticks)
+      g_state.pending_ticks += g_bios_access_time[static_cast<u32>(MemoryAccessSize::Word)] * word_count;
+
+    return true;
+  }
+  else
+  {
+    if (raise_exceptions)
+      CPU::RaiseException(address, Cop0Registers::CAUSE::MakeValueForException(Exception::IBE, false, false, 0));
+
+    std::memset(data, 0, sizeof(u32) * word_count);
+    return false;
+  }
+}
+
+TickCount CPU::GetInstructionReadTicks(VirtualMemoryAddress address)
+{
+  using namespace Bus;
+
+  address &= PHYSICAL_MEMORY_ADDRESS_MASK;
+
+  if (address < RAM_MIRROR_END)
+  {
+    return RAM_READ_TICKS;
+  }
+  else if (address >= BIOS_BASE && address < (BIOS_BASE + BIOS_SIZE))
+  {
+    return g_bios_access_time[static_cast<u32>(MemoryAccessSize::Word)];
+  }
+  else
+  {
+    return 0;
+  }
+}
+
+TickCount CPU::GetICacheFillTicks(VirtualMemoryAddress address)
+{
+  using namespace Bus;
+
+  address &= PHYSICAL_MEMORY_ADDRESS_MASK;
+
+  if (address < RAM_MIRROR_END)
+  {
+    return 1 * ((ICACHE_LINE_SIZE - (address & (ICACHE_LINE_SIZE - 1))) / sizeof(u32));
+  }
+  else if (address >= BIOS_BASE && address < (BIOS_BASE + BIOS_SIZE))
+  {
+    return g_bios_access_time[static_cast<u32>(MemoryAccessSize::Word)] *
+           ((ICACHE_LINE_SIZE - (address & (ICACHE_LINE_SIZE - 1))) / sizeof(u32));
+  }
+  else
+  {
+    return 0;
+  }
+}
+
+void CPU::CheckAndUpdateICacheTags(u32 line_count, TickCount uncached_ticks)
+{
+  VirtualMemoryAddress current_pc = g_state.pc & ICACHE_TAG_ADDRESS_MASK;
+  if (IsCachedAddress(current_pc))
+  {
+    TickCount ticks = 0;
+    TickCount cached_ticks_per_line = GetICacheFillTicks(current_pc);
+    for (u32 i = 0; i < line_count; i++, current_pc += ICACHE_LINE_SIZE)
+    {
+      const u32 line = GetICacheLine(current_pc);
+      if (g_state.icache_tags[line] != current_pc)
+      {
+        g_state.icache_tags[line] = current_pc;
+        ticks += cached_ticks_per_line;
+      }
+    }
+
+    g_state.pending_ticks += ticks;
+  }
+  else
+  {
+    g_state.pending_ticks += uncached_ticks;
+  }
+}
+
+u32 CPU::FillICache(VirtualMemoryAddress address)
+{
+  const u32 line = GetICacheLine(address);
+  u8* line_data = &g_state.icache_data[line * ICACHE_LINE_SIZE];
+  u32 line_tag;
+  switch ((address >> 2) & 0x03u)
+  {
+    case 0:
+      DoInstructionRead<true, true, 4, false>(address & ~(ICACHE_LINE_SIZE - 1u), line_data);
+      line_tag = GetICacheTagForAddress(address);
+      break;
+    case 1:
+      DoInstructionRead<true, true, 3, false>(address & (~(ICACHE_LINE_SIZE - 1u) | 0x4), line_data + 0x4);
+      line_tag = GetICacheTagForAddress(address) | 0x1;
+      break;
+    case 2:
+      DoInstructionRead<true, true, 2, false>(address & (~(ICACHE_LINE_SIZE - 1u) | 0x8), line_data + 0x8);
+      line_tag = GetICacheTagForAddress(address) | 0x3;
+      break;
+    case 3:
+    default:
+      DoInstructionRead<true, true, 1, false>(address & (~(ICACHE_LINE_SIZE - 1u) | 0xC), line_data + 0xC);
+      line_tag = GetICacheTagForAddress(address) | 0x7;
+      break;
+  }
+  g_state.icache_tags[line] = line_tag;
+
+  const u32 offset = GetICacheLineOffset(address);
+  u32 result;
+  std::memcpy(&result, &line_data[offset], sizeof(result));
+  return result;
+}
+
+void CPU::ClearICache()
+{
+  std::memset(g_state.icache_data.data(), 0, ICACHE_SIZE);
+  g_state.icache_tags.fill(ICACHE_INVALID_BITS);
+}
+
+namespace CPU {
+ALWAYS_INLINE_RELEASE static u32 ReadICache(VirtualMemoryAddress address)
+{
+  const u32 line = GetICacheLine(address);
+  const u8* line_data = &g_state.icache_data[line * ICACHE_LINE_SIZE];
+  const u32 offset = GetICacheLineOffset(address);
+  u32 result;
+  std::memcpy(&result, &line_data[offset], sizeof(result));
+  return result;
+}
+} // namespace CPU
+
+ALWAYS_INLINE_RELEASE bool CPU::FetchInstruction()
+{
+  DebugAssert(Common::IsAlignedPow2(g_state.npc, 4));
+
+  const PhysicalMemoryAddress address = g_state.npc;
+  switch (address >> 29)
+  {
+    case 0x00: // KUSEG 0M-512M
+    case 0x04: // KSEG0 - physical memory cached
+    {
+#if 0
+      DoInstructionRead<true, false, 1, false>(address, &g_state.next_instruction.bits);
+#else
+      if (CompareICacheTag(address))
+        g_state.next_instruction.bits = ReadICache(address);
+      else
+        g_state.next_instruction.bits = FillICache(address);
+#endif
+    }
+    break;
+
+    case 0x05: // KSEG1 - physical memory uncached
+    {
+      if (!DoInstructionRead<true, false, 1, true>(address, &g_state.next_instruction.bits))
+        return false;
+    }
+    break;
+
+    case 0x01: // KUSEG 512M-1024M
+    case 0x02: // KUSEG 1024M-1536M
+    case 0x03: // KUSEG 1536M-2048M
+    case 0x06: // KSEG2
+    case 0x07: // KSEG2
+    default:
+    {
+      CPU::RaiseException(Cop0Registers::CAUSE::MakeValueForException(Exception::IBE,
+                                                                      g_state.current_instruction_in_branch_delay_slot,
+                                                                      g_state.current_instruction_was_branch_taken, 0),
+                          address);
+      return false;
+    }
+  }
+
+  g_state.pc = g_state.npc;
+  g_state.npc += sizeof(g_state.next_instruction.bits);
+  return true;
+}
+
+bool CPU::FetchInstructionForInterpreterFallback()
+{
+  DebugAssert(Common::IsAlignedPow2(g_state.npc, 4));
+
+  const PhysicalMemoryAddress address = g_state.npc;
+  switch (address >> 29)
+  {
+    case 0x00: // KUSEG 0M-512M
+    case 0x04: // KSEG0 - physical memory cached
+    case 0x05: // KSEG1 - physical memory uncached
+    {
+      // We don't use the icache when doing interpreter fallbacks, because it's probably stale.
+      if (!DoInstructionRead<false, false, 1, true>(address, &g_state.next_instruction.bits))
+        return false;
+    }
+    break;
+
+    case 0x01: // KUSEG 512M-1024M
+    case 0x02: // KUSEG 1024M-1536M
+    case 0x03: // KUSEG 1536M-2048M
+    case 0x06: // KSEG2
+    case 0x07: // KSEG2
+    default:
+    {
+      CPU::RaiseException(Cop0Registers::CAUSE::MakeValueForException(Exception::IBE,
+                                                                      g_state.current_instruction_in_branch_delay_slot,
+                                                                      g_state.current_instruction_was_branch_taken, 0),
+                          address);
+      return false;
+    }
+  }
+
+  g_state.pc = g_state.npc;
+  g_state.npc += sizeof(g_state.next_instruction.bits);
+  return true;
+}
+
+bool CPU::SafeReadInstruction(VirtualMemoryAddress addr, u32* value)
+{
+  switch (addr >> 29)
+  {
+    case 0x00: // KUSEG 0M-512M
+    case 0x04: // KSEG0 - physical memory cached
+    case 0x05: // KSEG1 - physical memory uncached
+    {
+      // TODO: Check icache.
+      return DoInstructionRead<false, false, 1, false>(addr, value);
+    }
+
+    case 0x01: // KUSEG 512M-1024M
+    case 0x02: // KUSEG 1024M-1536M
+    case 0x03: // KUSEG 1536M-2048M
+    case 0x06: // KSEG2
+    case 0x07: // KSEG2
+    default:
+    {
+      return false;
+    }
+  }
+}
+
+template<MemoryAccessType type, MemoryAccessSize size>
+ALWAYS_INLINE bool CPU::DoSafeMemoryAccess(VirtualMemoryAddress address, u32& value)
+{
+  using namespace Bus;
+
+  switch (address >> 29)
+  {
+    case 0x00: // KUSEG 0M-512M
+    case 0x04: // KSEG0 - physical memory cached
+    {
+      address &= PHYSICAL_MEMORY_ADDRESS_MASK;
+      if ((address & DCACHE_LOCATION_MASK) == DCACHE_LOCATION)
+      {
+        const u32 offset = address & DCACHE_OFFSET_MASK;
+
+        if constexpr (type == MemoryAccessType::Read)
+        {
+          if constexpr (size == MemoryAccessSize::Byte)
+          {
+            value = CPU::g_state.dcache[offset];
+          }
+          else if constexpr (size == MemoryAccessSize::HalfWord)
+          {
+            u16 temp;
+            std::memcpy(&temp, &CPU::g_state.dcache[offset], sizeof(u16));
+            value = ZeroExtend32(temp);
+          }
+          else if constexpr (size == MemoryAccessSize::Word)
+          {
+            std::memcpy(&value, &CPU::g_state.dcache[offset], sizeof(u32));
+          }
+        }
+        else
+        {
+          if constexpr (size == MemoryAccessSize::Byte)
+          {
+            CPU::g_state.dcache[offset] = Truncate8(value);
+          }
+          else if constexpr (size == MemoryAccessSize::HalfWord)
+          {
+            std::memcpy(&CPU::g_state.dcache[offset], &value, sizeof(u16));
+          }
+          else if constexpr (size == MemoryAccessSize::Word)
+          {
+            std::memcpy(&CPU::g_state.dcache[offset], &value, sizeof(u32));
+          }
+        }
+
+        return true;
+      }
+    }
+    break;
+
+    case 0x01: // KUSEG 512M-1024M
+    case 0x02: // KUSEG 1024M-1536M
+    case 0x03: // KUSEG 1536M-2048M
+    case 0x06: // KSEG2
+    case 0x07: // KSEG2
+    {
+      // Above 512mb raises an exception.
+      return false;
+    }
+
+    case 0x05: // KSEG1 - physical memory uncached
+    {
+      address &= PHYSICAL_MEMORY_ADDRESS_MASK;
+    }
+    break;
+  }
+
+  if (address < RAM_MIRROR_END)
+  {
+    const u32 offset = address & g_ram_mask;
+    if constexpr (type == MemoryAccessType::Read)
+    {
+      if constexpr (size == MemoryAccessSize::Byte)
+      {
+        value = g_ram[offset];
+      }
+      else if constexpr (size == MemoryAccessSize::HalfWord)
+      {
+        u16 temp;
+        std::memcpy(&temp, &g_ram[offset], sizeof(temp));
+        value = ZeroExtend32(temp);
+      }
+      else if constexpr (size == MemoryAccessSize::Word)
+      {
+        std::memcpy(&value, &g_ram[offset], sizeof(u32));
+      }
+    }
+    else
+    {
+      const u32 page_index = offset / HOST_PAGE_SIZE;
+
+      if constexpr (size == MemoryAccessSize::Byte)
+      {
+        if (g_ram[offset] != Truncate8(value))
+        {
+          g_ram[offset] = Truncate8(value);
+          if (g_ram_code_bits[page_index])
+            CPU::CodeCache::InvalidateBlocksWithPageIndex(page_index);
+        }
+      }
+      else if constexpr (size == MemoryAccessSize::HalfWord)
+      {
+        const u16 new_value = Truncate16(value);
+        u16 old_value;
+        std::memcpy(&old_value, &g_ram[offset], sizeof(old_value));
+        if (old_value != new_value)
+        {
+          std::memcpy(&g_ram[offset], &new_value, sizeof(u16));
+          if (g_ram_code_bits[page_index])
+            CPU::CodeCache::InvalidateBlocksWithPageIndex(page_index);
+        }
+      }
+      else if constexpr (size == MemoryAccessSize::Word)
+      {
+        u32 old_value;
+        std::memcpy(&old_value, &g_ram[offset], sizeof(u32));
+        if (old_value != value)
+        {
+          std::memcpy(&g_ram[offset], &value, sizeof(u32));
+          if (g_ram_code_bits[page_index])
+            CPU::CodeCache::InvalidateBlocksWithPageIndex(page_index);
+        }
+      }
+    }
+
+    return true;
+  }
+  if constexpr (type == MemoryAccessType::Read)
+  {
+    if (address >= BIOS_BASE && address < (BIOS_BASE + BIOS_SIZE))
+    {
+      const u32 offset = (address & BIOS_MASK);
+      if constexpr (size == MemoryAccessSize::Byte)
+      {
+        value = ZeroExtend32(g_bios[offset]);
+      }
+      else if constexpr (size == MemoryAccessSize::HalfWord)
+      {
+        u16 halfword;
+        std::memcpy(&halfword, &g_bios[offset], sizeof(u16));
+        value = ZeroExtend32(halfword);
+      }
+      else
+      {
+        std::memcpy(&value, &g_bios[offset], sizeof(u32));
+      }
+
+      return true;
+    }
+  }
+  return false;
+}
+
+bool CPU::SafeReadMemoryByte(VirtualMemoryAddress addr, u8* value)
+{
+  u32 temp = 0;
+  if (!DoSafeMemoryAccess<MemoryAccessType::Read, MemoryAccessSize::Byte>(addr, temp))
+    return false;
+
+  *value = Truncate8(temp);
+  return true;
+}
+
+bool CPU::SafeReadMemoryHalfWord(VirtualMemoryAddress addr, u16* value)
+{
+  if ((addr & 1) == 0)
+  {
+    u32 temp = 0;
+    if (!DoSafeMemoryAccess<MemoryAccessType::Read, MemoryAccessSize::HalfWord>(addr, temp))
+      return false;
+
+    *value = Truncate16(temp);
+    return true;
+  }
+
+  u8 low, high;
+  if (!SafeReadMemoryByte(addr, &low) || !SafeReadMemoryByte(addr + 1, &high))
+    return false;
+
+  *value = (ZeroExtend16(high) << 8) | ZeroExtend16(low);
+  return true;
+}
+
+bool CPU::SafeReadMemoryWord(VirtualMemoryAddress addr, u32* value)
+{
+  if ((addr & 3) == 0)
+    return DoSafeMemoryAccess<MemoryAccessType::Read, MemoryAccessSize::Word>(addr, *value);
+
+  u16 low, high;
+  if (!SafeReadMemoryHalfWord(addr, &low) || !SafeReadMemoryHalfWord(addr + 2, &high))
+    return false;
+
+  *value = (ZeroExtend32(high) << 16) | ZeroExtend32(low);
+  return true;
+}
+
+bool CPU::SafeReadMemoryCString(VirtualMemoryAddress addr, std::string* value, u32 max_length /*= 1024*/)
+{
+  value->clear();
+
+  u8 ch;
+  while (SafeReadMemoryByte(addr, &ch))
+  {
+    if (ch == 0)
+      return true;
+
+    value->push_back(ch);
+    if (value->size() >= max_length)
+      return true;
+
+    addr++;
+  }
+
+  value->clear();
+  return false;
+}
+
+bool CPU::SafeWriteMemoryByte(VirtualMemoryAddress addr, u8 value)
+{
+  u32 temp = ZeroExtend32(value);
+  return DoSafeMemoryAccess<MemoryAccessType::Write, MemoryAccessSize::Byte>(addr, temp);
+}
+
+bool CPU::SafeWriteMemoryHalfWord(VirtualMemoryAddress addr, u16 value)
+{
+  if ((addr & 1) == 0)
+  {
+    u32 temp = ZeroExtend32(value);
+    return DoSafeMemoryAccess<MemoryAccessType::Write, MemoryAccessSize::HalfWord>(addr, temp);
+  }
+
+  return SafeWriteMemoryByte(addr, Truncate8(value)) && SafeWriteMemoryByte(addr + 1, Truncate8(value >> 8));
+}
+
+bool CPU::SafeWriteMemoryWord(VirtualMemoryAddress addr, u32 value)
+{
+  if ((addr & 3) == 0)
+    return DoSafeMemoryAccess<MemoryAccessType::Write, MemoryAccessSize::Word>(addr, value);
+
+  return SafeWriteMemoryHalfWord(addr, Truncate16(value >> 16)) &&
+         SafeWriteMemoryHalfWord(addr + 2, Truncate16(value >> 16));
+}
+
+void* CPU::GetDirectReadMemoryPointer(VirtualMemoryAddress address, MemoryAccessSize size, TickCount* read_ticks)
+{
+  using namespace Bus;
+
+  const u32 seg = (address >> 29);
+  if (seg != 0 && seg != 4 && seg != 5)
+    return nullptr;
+
+  const PhysicalMemoryAddress paddr = address & PHYSICAL_MEMORY_ADDRESS_MASK;
+  if (paddr < RAM_MIRROR_END)
+  {
+    if (read_ticks)
+      *read_ticks = RAM_READ_TICKS;
+
+    return &g_ram[paddr & g_ram_mask];
+  }
+
+  if ((paddr & DCACHE_LOCATION_MASK) == DCACHE_LOCATION)
+  {
+    if (read_ticks)
+      *read_ticks = 0;
+
+    return &g_state.dcache[paddr & DCACHE_OFFSET_MASK];
+  }
+
+  if (paddr >= BIOS_BASE && paddr < (BIOS_BASE + BIOS_SIZE))
+  {
+    if (read_ticks)
+      *read_ticks = g_bios_access_time[static_cast<u32>(size)];
+
+    return &g_bios[paddr & BIOS_MASK];
+  }
+
+  return nullptr;
+}
+
+void* CPU::GetDirectWriteMemoryPointer(VirtualMemoryAddress address, MemoryAccessSize size)
+{
+  using namespace Bus;
+
+  const u32 seg = (address >> 29);
+  if (seg != 0 && seg != 4 && seg != 5)
+    return nullptr;
+
+  const PhysicalMemoryAddress paddr = address & PHYSICAL_MEMORY_ADDRESS_MASK;
+
+#if 0
+  // Not enabled until we can protect code regions.
+  if (paddr < RAM_MIRROR_END)
+    return &g_ram[paddr & RAM_MASK];
+#endif
+
+  if ((paddr & DCACHE_LOCATION_MASK) == DCACHE_LOCATION)
+    return &g_state.dcache[paddr & DCACHE_OFFSET_MASK];
+
+  return nullptr;
+}
+
+template<MemoryAccessType type, MemoryAccessSize size>
+ALWAYS_INLINE_RELEASE bool CPU::DoAlignmentCheck(VirtualMemoryAddress address)
+{
+  if constexpr (size == MemoryAccessSize::HalfWord)
+  {
+    if (Common::IsAlignedPow2(address, 2))
+      return true;
+  }
+  else if constexpr (size == MemoryAccessSize::Word)
+  {
+    if (Common::IsAlignedPow2(address, 4))
+      return true;
+  }
+  else
+  {
+    return true;
+  }
+
+  g_state.cop0_regs.BadVaddr = address;
+  RaiseException(type == MemoryAccessType::Read ? Exception::AdEL : Exception::AdES);
+  return false;
+}
+
+#if 0
+static void MemoryBreakpoint(MemoryAccessType type, MemoryAccessSize size, VirtualMemoryAddress addr, u32 value)
+{
+  static constexpr const char* sizes[3] = { "byte", "halfword", "word" };
+  static constexpr const char* types[2] = { "read", "write" };
+
+  const u32 cycle = TimingEvents::GetGlobalTickCounter() + CPU::g_state.pending_ticks;
+
+#if 0
+  static std::FILE* fp = nullptr;
+  if (!fp)
+    fp = std::fopen("D:\\memory.txt", "wb");
+  if (fp)
+  {
+    std::fprintf(fp, "%u %s %s %08X %08X\n", cycle, types[static_cast<u32>(type)], sizes[static_cast<u32>(size)], addr, value);
+    std::fflush(fp);
+  }
+#endif
+
+#if 0
+  if (type == MemoryAccessType::Read && addr == 0x1F000084)
+    __debugbreak();
+#endif
+#if 0
+  if (type == MemoryAccessType::Write && addr == 0x000000B0 /*&& value == 0x3C080000*/)
+    __debugbreak();
+#endif
+
+#if 0 // TODO: MEMBP
+  if (type == MemoryAccessType::Write && address == 0x80113028)
+  {
+    if ((TimingEvents::GetGlobalTickCounter() + CPU::g_state.pending_ticks) == 5051485)
+      __debugbreak();
+
+    Log_WarningPrintf("VAL %08X @ %u", value, (TimingEvents::GetGlobalTickCounter() + CPU::g_state.pending_ticks));
+  }
+#endif
+}
+#define MEMORY_BREAKPOINT(type, size, addr, value) MemoryBreakpoint((type), (size), (addr), (value))
+#else
+#define MEMORY_BREAKPOINT(type, size, addr, value)
+#endif
+
+bool CPU::ReadMemoryByte(VirtualMemoryAddress addr, u8* value)
+{
+  *value = Truncate8(GetMemoryReadHandler(addr, MemoryAccessSize::Byte)(addr));
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    RaiseException(Exception::DBE);
+    return false;
+  }
+
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::Byte, addr, *value);
+  return true;
+}
+
+bool CPU::ReadMemoryHalfWord(VirtualMemoryAddress addr, u16* value)
+{
+  if (!DoAlignmentCheck<MemoryAccessType::Read, MemoryAccessSize::HalfWord>(addr))
+    return false;
+
+  *value = Truncate16(GetMemoryReadHandler(addr, MemoryAccessSize::HalfWord)(addr));
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    RaiseException(Exception::DBE);
+    return false;
+  }
+
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::HalfWord, addr, *value);
+  return true;
+}
+
+bool CPU::ReadMemoryWord(VirtualMemoryAddress addr, u32* value)
+{
+  if (!DoAlignmentCheck<MemoryAccessType::Read, MemoryAccessSize::Word>(addr))
+    return false;
+
+  *value = GetMemoryReadHandler(addr, MemoryAccessSize::Word)(addr);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    RaiseException(Exception::DBE);
+    return false;
+  }
+
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::Word, addr, *value);
+  return true;
+}
+
+bool CPU::WriteMemoryByte(VirtualMemoryAddress addr, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::Byte, addr, value);
+
+  GetMemoryWriteHandler(addr, MemoryAccessSize::Byte)(addr, value);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    RaiseException(Exception::DBE);
+    return false;
+  }
+
+  return true;
+}
+
+bool CPU::WriteMemoryHalfWord(VirtualMemoryAddress addr, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::HalfWord, addr, value);
+
+  if (!DoAlignmentCheck<MemoryAccessType::Write, MemoryAccessSize::HalfWord>(addr))
+    return false;
+
+  GetMemoryWriteHandler(addr, MemoryAccessSize::HalfWord)(addr, value);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    RaiseException(Exception::DBE);
+    return false;
+  }
+
+  return true;
+}
+
+bool CPU::WriteMemoryWord(VirtualMemoryAddress addr, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::Word, addr, value);
+
+  if (!DoAlignmentCheck<MemoryAccessType::Write, MemoryAccessSize::Word>(addr))
+    return false;
+
+  GetMemoryWriteHandler(addr, MemoryAccessSize::Word)(addr, value);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    RaiseException(Exception::DBE);
+    return false;
+  }
+
+  return true;
+}
+
+u64 CPU::Recompiler::Thunks::ReadMemoryByte(u32 address)
+{
+  const u32 value = GetMemoryReadHandler(address, MemoryAccessSize::Byte)(address);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    return static_cast<u64>(-static_cast<s64>(Exception::DBE));
+  }
+
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::Byte, address, value);
+  return ZeroExtend64(value);
+}
+
+u64 CPU::Recompiler::Thunks::ReadMemoryHalfWord(u32 address)
+{
+  if (!Common::IsAlignedPow2(address, 2)) [[unlikely]]
+  {
+    g_state.cop0_regs.BadVaddr = address;
+    return static_cast<u64>(-static_cast<s64>(Exception::AdEL));
+  }
+
+  const u32 value = GetMemoryReadHandler(address, MemoryAccessSize::HalfWord)(address);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    return static_cast<u64>(-static_cast<s64>(Exception::DBE));
+  }
+
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::HalfWord, address, value);
+  return ZeroExtend64(value);
+}
+
+u64 CPU::Recompiler::Thunks::ReadMemoryWord(u32 address)
+{
+  if (!Common::IsAlignedPow2(address, 4)) [[unlikely]]
+  {
+    g_state.cop0_regs.BadVaddr = address;
+    return static_cast<u64>(-static_cast<s64>(Exception::AdEL));
+  }
+
+  const u32 value = GetMemoryReadHandler(address, MemoryAccessSize::Word)(address);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    return static_cast<u64>(-static_cast<s64>(Exception::DBE));
+  }
+
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::Word, address, value);
+  return ZeroExtend64(value);
+}
+
+u32 CPU::Recompiler::Thunks::WriteMemoryByte(u32 address, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::Byte, address, value);
+
+  GetMemoryWriteHandler(address, MemoryAccessSize::Byte)(address, value);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    return static_cast<u32>(Exception::DBE);
+  }
+
+  return 0;
+}
+
+u32 CPU::Recompiler::Thunks::WriteMemoryHalfWord(u32 address, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::HalfWord, address, value);
+
+  if (!Common::IsAlignedPow2(address, 2)) [[unlikely]]
+  {
+    g_state.cop0_regs.BadVaddr = address;
+    return static_cast<u32>(Exception::AdES);
+  }
+
+  GetMemoryWriteHandler(address, MemoryAccessSize::HalfWord)(address, value);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    return static_cast<u32>(Exception::DBE);
+  }
+
+  return 0;
+}
+
+u32 CPU::Recompiler::Thunks::WriteMemoryWord(u32 address, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::Word, address, value);
+
+  if (!Common::IsAlignedPow2(address, 4)) [[unlikely]]
+  {
+    g_state.cop0_regs.BadVaddr = address;
+    return static_cast<u32>(Exception::AdES);
+  }
+
+  GetMemoryWriteHandler(address, MemoryAccessSize::Word)(address, value);
+  if (g_state.bus_error) [[unlikely]]
+  {
+    g_state.bus_error = false;
+    return static_cast<u32>(Exception::DBE);
+  }
+
+  return 0;
+}
+
+u32 CPU::Recompiler::Thunks::UncheckedReadMemoryByte(u32 address)
+{
+  const u32 value = GetMemoryReadHandler(address, MemoryAccessSize::Byte)(address);
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::Byte, address, value);
+  return value;
+}
+
+u32 CPU::Recompiler::Thunks::UncheckedReadMemoryHalfWord(u32 address)
+{
+  const u32 value = GetMemoryReadHandler(address, MemoryAccessSize::HalfWord)(address);
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::HalfWord, address, value);
+  return value;
+}
+
+u32 CPU::Recompiler::Thunks::UncheckedReadMemoryWord(u32 address)
+{
+  const u32 value = GetMemoryReadHandler(address, MemoryAccessSize::Word)(address);
+  MEMORY_BREAKPOINT(MemoryAccessType::Read, MemoryAccessSize::Word, address, value);
+  return value;
+}
+
+void CPU::Recompiler::Thunks::UncheckedWriteMemoryByte(u32 address, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::Byte, address, value);
+  GetMemoryWriteHandler(address, MemoryAccessSize::Byte)(address, value);
+}
+
+void CPU::Recompiler::Thunks::UncheckedWriteMemoryHalfWord(u32 address, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::HalfWord, address, value);
+  GetMemoryWriteHandler(address, MemoryAccessSize::HalfWord)(address, value);
+}
+
+void CPU::Recompiler::Thunks::UncheckedWriteMemoryWord(u32 address, u32 value)
+{
+  MEMORY_BREAKPOINT(MemoryAccessType::Write, MemoryAccessSize::Word, address, value);
+  GetMemoryWriteHandler(address, MemoryAccessSize::Word)(address, value);
+}
+
+#undef MEMORY_BREAKPOINT

src/core/cpu_core.h

@@ -68,6 +68,7 @@ struct State
   bool next_instruction_is_branch_delay_slot = false;
   bool branch_was_taken = false;
   bool exception_raised = false;
+  bool bus_error = false;
 
   // load delays
   Reg load_delay_reg = Reg::count;
@@ -84,7 +85,8 @@ struct State
   // 4 bytes of padding here on x64
   bool use_debug_dispatcher = false;
 
-  u8* fastmem_base = nullptr;
+  void* fastmem_base = nullptr;
+  void** memory_handlers = nullptr;
 
   // data cache (used as scratchpad)
   std::array<u8, DCACHE_SIZE> dcache = {};
@@ -102,7 +104,8 @@ void Shutdown();
 void Reset();
 bool DoState(StateWrapper& sw);
 void ClearICache();
-void UpdateFastmemBase();
+void UpdateMemoryPointers();
+void ExecutionModeChanged();
 
 /// Executes interpreter loop.
 void Execute();

src/core/cpu_core_private.h

@@ -102,16 +102,11 @@ ALWAYS_INLINE static VirtualMemoryAddress PhysicalAddressToVirtual(PhysicalMemor
   return bases[static_cast<u32>(segment)] | address;
 }
 
-// defined in bus.cpp - memory access functions which return false if an exception was thrown.
-bool FetchInstruction();
-bool FetchInstructionForInterpreterFallback();
+Bus::MemoryReadHandler GetMemoryReadHandler(VirtualMemoryAddress address, MemoryAccessSize size);
+Bus::MemoryWriteHandler GetMemoryWriteHandler(VirtualMemoryAddress address, MemoryAccessSize size);
+
+// memory access functions which return false if an exception was thrown.
 bool SafeReadInstruction(VirtualMemoryAddress addr, u32* value);
-bool ReadMemoryByte(VirtualMemoryAddress addr, u8* value);
-bool ReadMemoryHalfWord(VirtualMemoryAddress addr, u16* value);
-bool ReadMemoryWord(VirtualMemoryAddress addr, u32* value);
-bool WriteMemoryByte(VirtualMemoryAddress addr, u32 value);
-bool WriteMemoryHalfWord(VirtualMemoryAddress addr, u32 value);
-bool WriteMemoryWord(VirtualMemoryAddress addr, u32 value);
 void* GetDirectReadMemoryPointer(VirtualMemoryAddress address, MemoryAccessSize size, TickCount* read_ticks);
 void* GetDirectWriteMemoryPointer(VirtualMemoryAddress address, MemoryAccessSize size);
 

src/core/cpu_recompiler_code_generator.cpp

@@ -2687,18 +2687,18 @@ bool CodeGenerator::Compile_cop0(const CodeBlockInstruction& cbi)
               m_speculative_constants.cop0_sr = SpeculativeReadReg(cbi.instruction.r.rt);
 
             // changing SR[Isc] needs to update fastmem views
-            if (reg == Cop0Reg::SR && g_settings.IsUsingFastmem())
+            if (reg == Cop0Reg::SR)
             {
-              LabelType skip_fastmem_update;
+              LabelType skip_mem_update;
               Value old_value = m_register_cache.AllocateScratch(RegSize_32);
               EmitLoadCPUStructField(old_value.host_reg, RegSize_32, offset);
               EmitStoreCPUStructField(offset, value);
               EmitXor(old_value.host_reg, old_value.host_reg, value);
-              EmitBranchIfBitClear(old_value.host_reg, RegSize_32, 16, &skip_fastmem_update);
+              EmitBranchIfBitClear(old_value.host_reg, RegSize_32, 16, &skip_mem_update);
               m_register_cache.InhibitAllocation();
-              EmitFunctionCall(nullptr, &UpdateFastmemBase, m_register_cache.GetCPUPtr());
+              EmitFunctionCall(nullptr, &UpdateMemoryPointers, m_register_cache.GetCPUPtr());
               EmitUpdateFastmemBase();
-              EmitBindLabel(&skip_fastmem_update);
+              EmitBindLabel(&skip_mem_update);
               m_register_cache.UninhibitAllocation();
             }
             else

src/core/save_state_version.h

@@ -5,7 +5,7 @@
 #include "types.h"
 
 static constexpr u32 SAVE_STATE_MAGIC = 0x43435544;
-static constexpr u32 SAVE_STATE_VERSION = 60;
+static constexpr u32 SAVE_STATE_VERSION = 61;
 static constexpr u32 SAVE_STATE_MINIMUM_VERSION = 42;
 
 static_assert(SAVE_STATE_VERSION >= SAVE_STATE_MINIMUM_VERSION);

src/core/system.cpp

@@ -3510,6 +3510,7 @@ void System::CheckForSettingsChanges(const Settings& old_settings)
                                       TRANSLATE_SV("CPUExecutionMode", Settings::GetCPUExecutionModeDisplayName(
                                                                          g_settings.cpu_execution_mode))),
                           5.0f);
+      CPU::ExecutionModeChanged();
       CPU::CodeCache::Reinitialize();
       CPU::ClearICache();
     }
@@ -3521,6 +3522,7 @@ void System::CheckForSettingsChanges(const Settings& old_settings)
          g_settings.bios_tty_logging != old_settings.bios_tty_logging))
     {
       Host::AddOSDMessage(TRANSLATE_STR("OSDMessage", "Recompiler options changed, flushing all blocks."), 5.0f);
+      CPU::ExecutionModeChanged();
 
       // changing memory exceptions can re-enable fastmem
       if (g_settings.cpu_recompiler_memory_exceptions != old_settings.cpu_recompiler_memory_exceptions)