CPU/CodeCache: Always dynamically allocate code buffer

Reduces .bss size.

src/common/memmap.cpp

@@ -11,24 +11,36 @@
 
 #include "fmt/format.h"
 
+#include <memory>
+
 #if defined(_WIN32)
 #include "windows_headers.h"
+#include <Psapi.h>
 #elif defined(__APPLE__)
 #ifdef __aarch64__
 #include <pthread.h> // pthread_jit_write_protect_np()
 #endif
+#include <mach-o/dyld.h>
+#include <mach-o/getsect.h>
 #include <mach/mach_init.h>
 #include <mach/mach_port.h>
 #include <mach/mach_vm.h>
 #include <mach/vm_map.h>
+#include <sys/mman.h>
 #elif !defined(__ANDROID__)
 #include <cerrno>
+#include <dlfcn.h>
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #endif
 
-Log_SetChannel(MemoryArena);
+Log_SetChannel(MemMap);
+
+namespace MemMap {
+/// Allocates RWX memory at the specified address.
+static void* AllocateJITMemoryAt(const void* addr, size_t size);
+} // namespace MemMap
 
 #ifdef _WIN32
 
@@ -90,6 +102,44 @@ void MemMap::UnmapSharedMemory(void* baseaddr, size_t size)
     Panic("Failed to unmap shared memory");
 }
 
+const void* MemMap::GetBaseAddress()
+{
+  const HMODULE mod = GetModuleHandleW(nullptr);
+  if (!mod)
+    return nullptr;
+
+  MODULEINFO mi;
+  if (!GetModuleInformation(GetCurrentProcess(), mod, &mi, sizeof(mi)))
+    return mod;
+
+  return mi.lpBaseOfDll;
+}
+
+void* MemMap::AllocateJITMemoryAt(const void* addr, size_t size)
+{
+  void* ptr = static_cast<u8*>(VirtualAlloc(const_cast<void*>(addr), size,
+                                            addr ? (MEM_RESERVE | MEM_COMMIT) : MEM_COMMIT, PAGE_EXECUTE_READWRITE));
+  if (!ptr && !addr) [[unlikely]]
+    ERROR_LOG("VirtualAlloc(RWX, {}) for internal buffer failed: {}", size, GetLastError());
+
+  return ptr;
+}
+
+void MemMap::ReleaseJITMemory(void* ptr, size_t size)
+{
+  if (!VirtualFree(ptr, 0, MEM_RELEASE))
+    ERROR_LOG("Failed to free code pointer {}", static_cast<void*>(ptr));
+}
+
+#if defined(CPU_ARCH_ARM32) || defined(CPU_ARCH_ARM64) || defined(CPU_ARCH_RISCV64)
+
+void MemMap::FlushInstructionCache(void* address, size_t size)
+{
+  ::FlushInstructionCache(GetCurrentProcess(), address, size);
+}
+
+#endif
+
 SharedMemoryMappingArea::SharedMemoryMappingArea() = default;
 
 SharedMemoryMappingArea::~SharedMemoryMappingArea()
@@ -346,6 +396,93 @@ void MemMap::UnmapSharedMemory(void* baseaddr, size_t size)
     Panic("Failed to unmap shared memory");
 }
 
+const void* MemMap::GetBaseAddress()
+{
+  u32 name_buffer_size = 0;
+  _NSGetExecutablePath(nullptr, &name_buffer_size);
+  if (name_buffer_size > 0) [[likely]]
+  {
+    std::unique_ptr<char[]> name_buffer = std::make_unique_for_overwrite<char[]>(name_buffer_size + 1);
+    if (_NSGetExecutablePath(name_buffer.get(), &name_buffer_size) == 0) [[likely]]
+    {
+      name_buffer[name_buffer_size] = 0;
+
+      const struct segment_command_64* command = getsegbyname("__TEXT");
+      if (command) [[likely]]
+      {
+        const u8* base = reinterpret_cast<const u8*>(command->vmaddr);
+        const u32 image_count = _dyld_image_count();
+        for (u32 i = 0; i < image_count; i++)
+        {
+          if (std::strcmp(_dyld_get_image_name(i), name_buffer.get()) == 0)
+            return base + _dyld_get_image_vmaddr_slide(i);
+        }
+      }
+    }
+  }
+
+  return reinterpret_cast<const void*>(&GetBaseAddress);
+}
+
+void* MemMap::AllocateJITMemoryAt(const void* addr, size_t size)
+{
+#if !defined(__aarch64__)
+  kern_return_t ret = mach_vm_allocate(mach_task_self(), reinterpret_cast<mach_vm_address_t*>(&addr), size,
+                                       addr ? VM_FLAGS_FIXED : VM_FLAGS_ANYWHERE);
+  if (ret != KERN_SUCCESS)
+  {
+    ERROR_LOG("mach_vm_allocate() returned {}", ret);
+    return nullptr;
+  }
+
+  ret = mach_vm_protect(mach_task_self(), reinterpret_cast<mach_vm_address_t>(addr), size, false,
+                        VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE);
+  if (ret != KERN_SUCCESS)
+  {
+    ERROR_LOG("mach_vm_protect() returned {}", ret);
+    mach_vm_deallocate(mach_task_self(), reinterpret_cast<mach_vm_address_t>(addr), size);
+    return nullptr;
+  }
+
+  return const_cast<void*>(addr);
+#else
+  // On ARM64, we need to use MAP_JIT, which means we can't use MAP_FIXED.
+  if (addr)
+    return nullptr;
+
+  constexpr int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_JIT;
+  void* ptr = mmap(const_cast<void*>(addr), size, PROT_READ | PROT_WRITE | PROT_EXEC, flags, -1, 0);
+  if (ptr == MAP_FAILED)
+  {
+    ERROR_LOG("mmap(RWX, {}) for internal buffer failed: {}", size, errno);
+    return nullptr;
+  }
+
+  return ptr;
+#endif
+}
+
+void MemMap::ReleaseJITMemory(void* ptr, size_t size)
+{
+#if !defined(__aarch64__)
+  const kern_return_t res = mach_vm_deallocate(mach_task_self(), reinterpret_cast<mach_vm_address_t>(ptr), size);
+  if (res != KERN_SUCCESS)
+    ERROR_LOG("mach_vm_deallocate() failed: {}", res);
+#else
+  if (munmap(ptr, size) != 0)
+    ERROR_LOG("Failed to free code pointer {}", static_cast<void*>(ptr));
+#endif
+}
+
+#if defined(CPU_ARCH_ARM32) || defined(CPU_ARCH_ARM64) || defined(CPU_ARCH_RISCV64)
+
+void MemMap::FlushInstructionCache(void* address, size_t size)
+{
+  __builtin___clear_cache(reinterpret_cast<char*>(address), reinterpret_cast<char*>(address) + size);
+}
+
+#endif
+
 SharedMemoryMappingArea::SharedMemoryMappingArea() = default;
 
 SharedMemoryMappingArea::~SharedMemoryMappingArea()
@@ -531,6 +668,72 @@ void MemMap::UnmapSharedMemory(void* baseaddr, size_t size)
     Panic("Failed to unmap shared memory");
 }
 
+const void* MemMap::GetBaseAddress()
+{
+#ifndef __APPLE__
+  Dl_info info;
+  if (dladdr(reinterpret_cast<const void*>(&GetBaseAddress), &info) == 0)
+  {
+    ERROR_LOG("dladdr() failed");
+    return nullptr;
+  }
+
+  return info.dli_fbase;
+#else
+#error Fixme
+#endif
+}
+
+void* MemMap::AllocateJITMemoryAt(const void* addr, size_t size)
+{
+  int flags = MAP_PRIVATE | MAP_ANONYMOUS;
+#if defined(__linux__)
+  // Linux does the right thing, allows us to not disturb an existing mapping.
+  if (addr)
+    flags |= MAP_FIXED_NOREPLACE;
+#elif defined(__FreeBSD__)
+  // FreeBSD achieves the same with MAP_FIXED and MAP_EXCL.
+  if (addr)
+    flags |= MAP_FIXED | MAP_EXCL;
+#else
+  // Targeted mapping not available?
+  if (addr)
+    return nullptr;
+#endif
+
+  void* ptr = mmap(const_cast<void*>(addr), size, PROT_READ | PROT_WRITE | PROT_EXEC, flags, -1, 0);
+  if (ptr == MAP_FAILED)
+  {
+    if (!addr)
+      ERROR_LOG("mmap(RWX, {}) for internal buffer failed: {}", size, errno);
+
+    return nullptr;
+  }
+  else if (addr && ptr != addr) [[unlikely]]
+  {
+    if (munmap(ptr, size) != 0)
+      ERROR_LOG("Failed to munmap() incorrectly hinted allocation: {}", errno);
+    return nullptr;
+  }
+
+  return ptr;
+}
+
+void MemMap::ReleaseJITMemory(void* ptr, size_t size)
+{
+  if (munmap(ptr, size) != 0)
+    ERROR_LOG("Failed to free code pointer {}", static_cast<void*>(ptr));
+}
+
+#if defined(CPU_ARCH_ARM32) || defined(CPU_ARCH_ARM64) || defined(CPU_ARCH_RISCV64)
+
+void MemMap::FlushInstructionCache(void* address, size_t size)
+{
+  __builtin___clear_cache(reinterpret_cast<char*>(address), reinterpret_cast<char*>(address) + size);
+}
+
+#endif
+
 SharedMemoryMappingArea::SharedMemoryMappingArea() = default;
 
 SharedMemoryMappingArea::~SharedMemoryMappingArea()
@@ -591,3 +794,95 @@ bool SharedMemoryMappingArea::Unmap(void* map_base, size_t map_size)
 }
 
 #endif
+
+void* MemMap::AllocateJITMemory(size_t size)
+{
+  const u8* base =
+    reinterpret_cast<const u8*>(Common::AlignDownPow2(reinterpret_cast<uintptr_t>(GetBaseAddress()), HOST_PAGE_SIZE));
+  u8* ptr = nullptr;
+#if !defined(CPU_ARCH_ARM64) || !defined(__APPLE__)
+
+#if defined(CPU_ARCH_X64)
+  static constexpr size_t assume_binary_size = 64 * 1024 * 1024;
+  static constexpr size_t step = 64 * 1024 * 1024;
+  static constexpr size_t max_displacement = 0x80000000u;
+#elif defined(CPU_ARCH_ARM64) || defined(CPU_ARCH_RISCV64)
+  static constexpr size_t assume_binary_size = 16 * 1024 * 1024;
+  static constexpr size_t step = 8 * 1024 * 1024;
+  static constexpr size_t max_displacement =
+    1024 * 1024 * 1024; // technically 4GB, but we don't want to spend that much time trying
+#elif defined(CPU_ARCH_ARM32)
+  static constexpr size_t assume_binary_size = 8 * 1024 * 1024; // Wishful thinking...
+  static constexpr size_t step = 2 * 1024 * 1024;
+  static constexpr size_t max_displacement = 32 * 1024 * 1024;
+#else
+#error Unhandled architecture.
+#endif
+
+  const size_t max_displacement_from_start = max_displacement - size;
+  Assert(size <= max_displacement);
+
+  // Try to find a region in the max displacement range of the process base address.
+  // Assume that the DuckStation binary will at max be some size, release is currently around 12MB on Windows.
+  // Therefore the max offset is +/- 12MB + code_size. Try allocating in steps by incrementing the pointer, then if no
+  // address range is found, go backwards from the base address (which will probably fail).
+  const u8* min_address =
+    base - std::min(reinterpret_cast<ptrdiff_t>(base), static_cast<ptrdiff_t>(max_displacement_from_start));
+  const u8* max_address = base + max_displacement_from_start;
+  VERBOSE_LOG("Base address: {}", static_cast<const void*>(base));
+  VERBOSE_LOG("Acceptable address range: {} - {}", static_cast<const void*>(min_address),
+              static_cast<const void*>(max_address));
+
+  // Start offset by the expected binary size.
+  for (const u8* current_address = base + assume_binary_size;; current_address += step)
+  {
+    VERBOSE_LOG("Trying {} (displacement 0x{:X})", static_cast<const void*>(current_address),
+                static_cast<ptrdiff_t>(current_address - base));
+    if ((ptr = static_cast<u8*>(AllocateJITMemoryAt(current_address, size))))
+      break;
+
+    if ((reinterpret_cast<uintptr_t>(current_address) + step) > reinterpret_cast<uintptr_t>(max_address) ||
+        (reinterpret_cast<uintptr_t>(current_address) + step) < reinterpret_cast<uintptr_t>(current_address))
+    {
+      break;
+    }
+  }
+
+  // Try before (will likely fail).
+  if (!ptr && reinterpret_cast<uintptr_t>(base) >= step)
+  {
+    for (const u8* current_address = base - step;; current_address -= step)
+    {
+      VERBOSE_LOG("Trying {} (displacement 0x{:X})", static_cast<const void*>(current_address),
+                  static_cast<ptrdiff_t>(base - current_address));
+      if ((ptr = static_cast<u8*>(AllocateJITMemoryAt(current_address, size))))
+        break;
+
+      if ((reinterpret_cast<uintptr_t>(current_address) - step) < reinterpret_cast<uintptr_t>(min_address) ||
+          (reinterpret_cast<uintptr_t>(current_address) - step) > reinterpret_cast<uintptr_t>(current_address))
+      {
+        break;
+      }
+    }
+  }
+
+  if (!ptr)
+  {
+#ifdef CPU_ARCH_X64
+    ERROR_LOG("Failed to allocate JIT buffer in range, expect crashes.");
+#endif
+    if (!(ptr = static_cast<u8*>(AllocateJITMemoryAt(nullptr, size))))
+      return ptr;
+  }
+#else
+  // We cannot control where the buffer gets allocated on Apple Silicon. Hope for the best.
+  if (!(ptr = static_cast<u8*>(AllocateJITMemoryAt(nullptr, size))))
+    return ptr;
+#endif
+
+  INFO_LOG("Allocated JIT buffer of size {} at {} (0x{:X} bytes / {} MB away)", size, static_cast<void*>(ptr),
+           std::abs(static_cast<ptrdiff_t>(ptr - base)),
+           (std::abs(static_cast<ptrdiff_t>(ptr - base)) + (1024 * 1024 - 1)) / (1024 * 1024));
+
+  return ptr;
+}

src/common/memmap.h

@@ -58,6 +58,25 @@ void* MapSharedMemory(void* handle, size_t offset, void* baseaddr, size_t size,
 void UnmapSharedMemory(void* baseaddr, size_t size);
 bool MemProtect(void* baseaddr, size_t size, PageProtect mode);
 
+/// Returns the base address for the current process.
+const void* GetBaseAddress();
+
+/// Allocates RWX memory in branch range from the base address.
+void* AllocateJITMemory(size_t size);
+
+/// Releases RWX memory.
+void ReleaseJITMemory(void* ptr, size_t size);
+
+/// Flushes the instruction cache on the host for the specified range.
+/// Only needed outside of X86, X86 has coherent D/I cache.
+#if !defined(CPU_ARCH_ARM32) && !defined(CPU_ARCH_ARM64) && !defined(CPU_ARCH_RISCV64)
+// clang-format off
+ALWAYS_INLINE static void FlushInstructionCache(void* address, size_t size) { }
+// clang-format on
+#else
+void FlushInstructionCache(void* address, size_t size);
+#endif
+
 /// JIT write protect for Apple Silicon. Needs to be called prior to writing to any RWX pages.
 #if !defined(__APPLE__) || !defined(__aarch64__)
 // clang-format off

src/core/cpu_code_cache.cpp

@@ -123,22 +123,27 @@ PerfScope MIPSPerfScope("MIPS");
 
 #endif
 
-// Currently remapping the code buffer doesn't work in macOS. TODO: Make dynamic instead...
-#ifndef __APPLE__
-#define USE_STATIC_CODE_BUFFER 1
-#endif
-
 #if defined(CPU_ARCH_ARM32)
 // Use a smaller code buffer size on AArch32 to have a better chance of being in range.
-static constexpr u32 RECOMPILER_CODE_CACHE_SIZE = 16 * 1024 * 1024;
+static constexpr u32 RECOMPILER_CODE_CACHE_SIZE = 20 * 1024 * 1024;
-static constexpr u32 RECOMPILER_FAR_CODE_CACHE_SIZE = 8 * 1024 * 1024;
+static constexpr u32 RECOMPILER_FAR_CODE_CACHE_SIZE = 4 * 1024 * 1024;
 #else
-static constexpr u32 RECOMPILER_CODE_CACHE_SIZE = 32 * 1024 * 1024;
+static constexpr u32 RECOMPILER_CODE_CACHE_SIZE = 48 * 1024 * 1024;
 static constexpr u32 RECOMPILER_FAR_CODE_CACHE_SIZE = 16 * 1024 * 1024;
 #endif
 
-#ifdef USE_STATIC_CODE_BUFFER
+// On Linux ARM32/ARM64, we use a dedicated section in the ELF for storing code.
-alignas(HOST_PAGE_SIZE) static u8 s_code_storage[RECOMPILER_CODE_CACHE_SIZE + RECOMPILER_FAR_CODE_CACHE_SIZE];
+// This is because without ASLR, or on certain ASLR offsets, the sbrk() heap ends up immediately following the text/data
+// sections, which means there isn't a large enough gap to fit within range on ARM32.
+#if defined(__linux__) && (defined(CPU_ARCH_ARM32) || defined(CPU_ARCH_ARM64))
+#define USE_CODE_BUFFER_SECTION 1
+#ifdef __clang__
+#pragma clang section bss = ".jitstorage"
+__attribute__((aligned(HOST_PAGE_SIZE))) static u8 s_code_buffer_ptr[RECOMPILER_CODE_CACHE_SIZE];
+#pragma clang section bss = ""
+#endif
+#else
+static u8* s_code_buffer_ptr = nullptr;
 #endif
 
 static JitCodeBuffer s_code_buffer;
@@ -162,20 +167,26 @@ bool CPU::CodeCache::IsUsingFastmem()
 
 bool CPU::CodeCache::ProcessStartup(Error* error)
 {
-  AllocateLUTs();
+#ifdef USE_CODE_BUFFER_SECTION
-
+  const u8* module_base = static_cast<const u8*>(MemMap::GetBaseAddress());
-#ifdef USE_STATIC_CODE_BUFFER
+  INFO_LOG("Using JIT buffer section of size {} at {} (0x{:X} bytes / {} MB away)", sizeof(s_code_buffer_ptr),
-  const bool has_buffer =
+           static_cast<void*>(s_code_buffer_ptr), std::abs(static_cast<ptrdiff_t>(s_code_buffer_ptr - module_base)),
-    s_code_buffer.Initialize(s_code_storage, sizeof(s_code_storage), RECOMPILER_FAR_CODE_CACHE_SIZE, HOST_PAGE_SIZE);
+           (std::abs(static_cast<ptrdiff_t>(s_code_buffer_ptr - module_base)) + (1024 * 1024 - 1)) / (1024 * 1024));
+  const bool code_buffer_allocated =
+    MemMap::MemProtect(s_code_buffer_ptr, RECOMPILER_CODE_CACHE_SIZE, PageProtect::ReadWriteExecute);
 #else
-  const bool has_buffer = false;
+  s_code_buffer_ptr = static_cast<u8*>(MemMap::AllocateJITMemory(RECOMPILER_CODE_CACHE_SIZE));
+  const bool code_buffer_allocated = (s_code_buffer_ptr != nullptr);
 #endif
-  if (!has_buffer && !s_code_buffer.Allocate(RECOMPILER_CODE_CACHE_SIZE, RECOMPILER_FAR_CODE_CACHE_SIZE))
+  if (!code_buffer_allocated) [[unlikely]]
   {
-    Error::SetStringView(error, "Failed to initialize code space");
+    Error::SetStringView(error, "Failed to allocate code storage. The log may contain more information, you will need "
+                                "to run DuckStation with -earlyconsole in the command line.");
     return false;
   }
 
+  AllocateLUTs();
+
   if (!PageFaultHandler::Install(error))
     return false;
 
@@ -184,17 +195,21 @@ bool CPU::CodeCache::ProcessStartup(Error* error)
 
 void CPU::CodeCache::ProcessShutdown()
 {
-  s_code_buffer.Destroy();
   DeallocateLUTs();
+
+#ifndef USE_CODE_BUFFER_SECTION
+  MemMap::ReleaseJITMemory(s_code_buffer_ptr, RECOMPILER_CODE_CACHE_SIZE);
+#endif
 }
 
 void CPU::CodeCache::Initialize()
 {
   Assert(s_blocks.empty());
 
+  // TODO: Reduce far code size when not using memory exceptions.
   if (IsUsingAnyRecompiler())
   {
-    s_code_buffer.Reset();
+    s_code_buffer.Reset(s_code_buffer_ptr, RECOMPILER_CODE_CACHE_SIZE, RECOMPILER_FAR_CODE_CACHE_SIZE);
     CompileASMFunctions();
     ResetCodeLUT();
   }
@@ -219,7 +234,7 @@ void CPU::CodeCache::Reset()
   if (IsUsingAnyRecompiler())
   {
     ClearASMFunctions();
-    s_code_buffer.Reset();
+    s_code_buffer.Reset(s_code_buffer_ptr, RECOMPILER_CODE_CACHE_SIZE, RECOMPILER_FAR_CODE_CACHE_SIZE);
     CompileASMFunctions();
     ResetCodeLUT();
   }

src/core/cpu_recompiler_code_generator_aarch32.cpp

@@ -1,9 +1,10 @@
-// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
 #include "common/align.h"
 #include "common/assert.h"
 #include "common/log.h"
+#include "common/memmap.h"
 
 #include "cpu_code_cache_private.h"
 #include "cpu_core.h"
@@ -171,7 +172,7 @@ u32 CPU::CodeCache::EmitJump(void* code, const void* dst, bool flush_icache)
   }
 
   if (flush_icache)
-    JitCodeBuffer::FlushInstructionCache(code, kA32InstructionSizeInBytes);
+    MemMap::FlushInstructionCache(code, kA32InstructionSizeInBytes);
 
   return kA32InstructionSizeInBytes;
 }
@@ -202,7 +203,7 @@ u8* CPU::Recompiler::armGetJumpTrampoline(const void* target)
   s_trampoline_targets.emplace(target, offset);
   s_trampoline_used = offset + static_cast<u32>(size);
 
-  JitCodeBuffer::FlushInstructionCache(start, size);
+  MemMap::FlushInstructionCache(start, size);
   return start;
 }
 
@@ -1790,7 +1791,7 @@ void CodeGenerator::BackpatchLoadStore(void* host_pc, const CodeCache::Loadstore
   for (s32 i = 0; i < nops; i++)
     emit.nop();
 
-  JitCodeBuffer::FlushInstructionCache(host_pc, lbi.code_size);
+  MemMap::FlushInstructionCache(host_pc, lbi.code_size);
 }
 
 void CodeGenerator::EmitLoadGlobal(HostReg host_reg, RegSize size, const void* ptr)

src/core/cpu_recompiler_code_generator_aarch64.cpp

@@ -1,9 +1,11 @@
-// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
 #include "common/align.h"
 #include "common/assert.h"
 #include "common/log.h"
+#include "common/memmap.h"
+
 #include "cpu_code_cache_private.h"
 #include "cpu_core.h"
 #include "cpu_core_private.h"
@@ -274,7 +276,7 @@ u8* CPU::Recompiler::armGetJumpTrampoline(const void* target)
   s_trampoline_targets.emplace(target, offset);
   s_trampoline_used = offset + static_cast<u32>(size);
 
-  JitCodeBuffer::FlushInstructionCache(start, size);
+  MemMap::FlushInstructionCache(start, size);
   return start;
 }
 
@@ -316,7 +318,7 @@ u32 CPU::CodeCache::EmitJump(void* code, const void* dst, bool flush_icache)
   const u32 new_code = B | Assembler::ImmUncondBranch(disp);
   std::memcpy(code, &new_code, sizeof(new_code));
   if (flush_icache)
-    JitCodeBuffer::FlushInstructionCache(code, kInstructionSize);
+    MemMap::FlushInstructionCache(code, kInstructionSize);
 
   return kInstructionSize;
 }
@@ -2100,7 +2102,7 @@ void CodeGenerator::BackpatchLoadStore(void* host_pc, const CodeCache::Loadstore
   for (s32 i = 0; i < nops; i++)
     emit.nop();
 
-  JitCodeBuffer::FlushInstructionCache(host_pc, lbi.code_size);
+  MemMap::FlushInstructionCache(host_pc, lbi.code_size);
 }
 
 void CodeGenerator::EmitLoadGlobal(HostReg host_reg, RegSize size, const void* ptr)

src/core/cpu_recompiler_code_generator_x64.cpp

@@ -12,6 +12,7 @@
 #include "common/align.h"
 #include "common/assert.h"
 #include "common/log.h"
+#include "common/memmap.h"
 
 #ifdef CPU_ARCH_X64
 
@@ -1768,15 +1769,8 @@ void CodeGenerator::RestoreStackAfterCall(u32 adjust_size)
 
 void CodeGenerator::EmitCall(const void* ptr)
 {
-  if (Xbyak::inner::IsInInt32(reinterpret_cast<size_t>(ptr) - reinterpret_cast<size_t>(m_emit->getCurr())))
+  DebugAssert(Xbyak::inner::IsInInt32(reinterpret_cast<size_t>(ptr) - reinterpret_cast<size_t>(m_emit->getCurr())));
-  {
+  m_emit->call(ptr);
-    m_emit->call(ptr);
-  }
-  else
-  {
-    m_emit->mov(GetHostReg64(RRETURN), reinterpret_cast<size_t>(ptr));
-    m_emit->call(GetHostReg64(RRETURN));
-  }
 }
 
 void CodeGenerator::EmitFunctionCallPtr(Value* return_value, const void* ptr)
@@ -2530,7 +2524,7 @@ void CodeGenerator::BackpatchLoadStore(void* host_pc, const CodeCache::Loadstore
   for (s32 i = 0; i < nops; i++)
     cg.nop();
 
-  JitCodeBuffer::FlushInstructionCache(host_pc, lbi.code_size);
+  MemMap::FlushInstructionCache(host_pc, lbi.code_size);
 }
 
 void CodeGenerator::EmitLoadGlobal(HostReg host_reg, RegSize size, const void* ptr)

src/core/system.cpp

@@ -318,6 +318,34 @@ void System::CheckCacheLineSize()
   }
 }
 
+bool System::Internal::ProcessStartup(Error* error)
+{
+  Common::Timer timer;
+
+  // Allocate JIT memory as soon as possible.
+  if (!CPU::CodeCache::ProcessStartup(error))
+    return false;
+
+  // Fastmem alloc *must* come after JIT alloc, otherwise it tends to eat the 4GB region after the executable on MacOS.
+  if (!Bus::AllocateMemory(error))
+  {
+    CPU::CodeCache::ProcessShutdown();
+    return false;
+  }
+
+  VERBOSE_LOG("Memory allocation took {} ms.", timer.GetTimeMilliseconds());
+
+  CheckCacheLineSize();
+
+  return true;
+}
+
+void System::Internal::ProcessShutdown()
+{
+  Bus::ReleaseMemory();
+  CPU::CodeCache::ProcessShutdown();
+}
+
 bool System::Internal::CPUThreadInitialize(Error* error)
 {
 #ifdef _WIN32
@@ -332,17 +360,9 @@ bool System::Internal::CPUThreadInitialize(Error* error)
   }
 #endif
 
-  if (!CPU::CodeCache::ProcessStartup(error) || !Bus::AllocateMemory(error))
-  {
-    CPUThreadShutdown();
-    return false;
-  }
-
   // This will call back to Host::LoadSettings() -> ReloadSources().
   LoadSettings(false);
 
-  CheckCacheLineSize();
-
 #ifdef ENABLE_RAINTEGRATION
   if (Host::GetBaseBoolSettingValue("Cheevos", "UseRAIntegration", false))
     Achievements::SwitchToRAIntegration();
@@ -377,9 +397,6 @@ void System::Internal::CPUThreadShutdown()
 
   InputManager::CloseSources();
 
-  CPU::CodeCache::ProcessShutdown();
-  Bus::ReleaseMemory();
-
 #ifdef _WIN32
   CoUninitialize();
 #endif

src/core/system.h

@@ -504,10 +504,16 @@ namespace Internal {
 /// Performs mandatory hardware checks.
 bool PerformEarlyHardwareChecks(Error* error);
 
-/// Called on process startup.
+/// Called on process startup, as early as possible.
-bool CPUThreadInitialize(Error* error);
+bool ProcessStartup(Error* error);
 
 /// Called on process shutdown.
+void ProcessShutdown();
+
+/// Called on CPU thread initialization.
+bool CPUThreadInitialize(Error* error);
+
+/// Called on CPU thread shutdown.
 void CPUThreadShutdown();
 
 /// Polls input, updates subsystems which are present while paused/inactive.

src/duckstation-qt/qthost.cpp

@@ -90,6 +90,7 @@ static constexpr u32 GDB_SERVER_POLLING_INTERVAL = 1;
 //////////////////////////////////////////////////////////////////////////
 namespace QtHost {
 static bool PerformEarlyHardwareChecks();
+static bool EarlyProcessStartup();
 static void RegisterTypes();
 static bool InitializeConfig(std::string settings_filename);
 static bool ShouldUsePortableMode();
@@ -128,11 +129,26 @@ EmuThread::EmuThread(QThread* ui_thread) : QThread(), m_ui_thread(ui_thread)
 
 EmuThread::~EmuThread() = default;
 
+void QtHost::RegisterTypes()
+{
+  // Register any standard types we need elsewhere
+  qRegisterMetaType<std::optional<WindowInfo>>("std::optional<WindowInfo>()");
+  qRegisterMetaType<std::optional<bool>>();
+  qRegisterMetaType<std::function<void()>>("std::function<void()>");
+  qRegisterMetaType<std::shared_ptr<SystemBootParameters>>();
+  qRegisterMetaType<const GameList::Entry*>();
+  qRegisterMetaType<GPURenderer>("GPURenderer");
+  qRegisterMetaType<InputBindingKey>("InputBindingKey");
+  qRegisterMetaType<std::string>("std::string");
+  qRegisterMetaType<std::vector<std::pair<std::string, std::string>>>(
+    "std::vector<std::pair<std::string, std::string>>");
+}
+
 bool QtHost::PerformEarlyHardwareChecks()
 {
   Error error;
   const bool okay = System::Internal::PerformEarlyHardwareChecks(&error);
-  if (okay && !error.IsValid())
+  if (okay && !error.IsValid()) [[likely]]
     return true;
 
   if (okay)
@@ -149,19 +165,15 @@ bool QtHost::PerformEarlyHardwareChecks()
   return okay;
 }
 
-void QtHost::RegisterTypes()
+bool QtHost::EarlyProcessStartup()
 {
-  // Register any standard types we need elsewhere
+  Error error;
-  qRegisterMetaType<std::optional<WindowInfo>>("std::optional<WindowInfo>()");
+  if (System::Internal::ProcessStartup(&error)) [[likely]]
-  qRegisterMetaType<std::optional<bool>>();
+    return true;
-  qRegisterMetaType<std::function<void()>>("std::function<void()>");
+
-  qRegisterMetaType<std::shared_ptr<SystemBootParameters>>();
+  QMessageBox::critical(nullptr, QStringLiteral("Process Startup Failed"),
-  qRegisterMetaType<const GameList::Entry*>();
+                        QString::fromStdString(error.GetDescription()));
-  qRegisterMetaType<GPURenderer>("GPURenderer");
+  return false;
-  qRegisterMetaType<InputBindingKey>("InputBindingKey");
-  qRegisterMetaType<std::string>("std::string");
-  qRegisterMetaType<std::vector<std::pair<std::string, std::string>>>(
-    "std::vector<std::pair<std::string, std::string>>");
 }
 
 bool QtHost::InBatchMode()
@@ -452,7 +464,7 @@ bool QtHost::InitializeConfig(std::string settings_filename)
   EmuFolders::EnsureFoldersExist();
   MigrateSettings();
 
-  // We need to create the console window early, otherwise it appears behind the main window.
+  // We need to create the console window early, otherwise it appears in front of the main window.
   if (!Log::IsConsoleOutputEnabled() &&
       s_base_settings_interface->GetBoolValue("Logging", "LogToConsole", Settings::DEFAULT_LOG_TO_CONSOLE))
   {
@@ -2508,6 +2520,9 @@ int main(int argc, char* argv[])
   if (!QtHost::ParseCommandLineParametersAndInitializeConfig(app, autoboot))
     return EXIT_FAILURE;
 
+  if (!QtHost::EarlyProcessStartup())
+    return EXIT_FAILURE;
+
   // Remove any previous-version remanants.
   if (s_cleanup_after_update)
     AutoUpdaterDialog::cleanupAfterUpdate();
@@ -2581,5 +2596,7 @@ shutdown_and_exit:
   // Ensure log is flushed.
   Log::SetFileOutputParams(false, nullptr);
 
+  System::Internal::ProcessShutdown();
+
   return result;
 }

src/util/jit_code_buffer.cpp

@@ -1,301 +1,40 @@
-// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
 #include "jit_code_buffer.h"
 
 #include "common/align.h"
 #include "common/assert.h"
-#include "common/log.h"
 #include "common/memmap.h"
 
 #include <algorithm>
-
+#include <cstring>
-Log_SetChannel(JitCodeBuffer);
-
-#if defined(_WIN32)
-#include "common/windows_headers.h"
-#else
-#include <errno.h>
-#include <sys/mman.h>
-#ifdef __APPLE__
-#include <mach/mach_init.h>
-#include <mach/mach_vm.h>
-#endif
-#endif
 
 JitCodeBuffer::JitCodeBuffer() = default;
 
-JitCodeBuffer::JitCodeBuffer(u32 size, u32 far_code_size)
+JitCodeBuffer::~JitCodeBuffer() = default;
+
+void JitCodeBuffer::Reset(void* ptr, u32 size, u32 far_code_size /* = 0 */)
 {
-  if (!Allocate(size, far_code_size))
+  Assert(far_code_size < size);
-    Panic("Failed to allocate code space");
-}
-
-JitCodeBuffer::JitCodeBuffer(void* buffer, u32 size, u32 far_code_size, u32 guard_pages)
-{
-  if (!Initialize(buffer, size, far_code_size))
-    Panic("Failed to initialize code space");
-}
-
-JitCodeBuffer::~JitCodeBuffer()
-{
-  Destroy();
-}
-
-bool JitCodeBuffer::Allocate(u32 size /* = 64 * 1024 * 1024 */, u32 far_code_size /* = 0 */)
-{
-  Destroy();
-
-  m_total_size = size + far_code_size;
-
-#ifdef CPU_ARCH_X64
-  // Try to find a region in 32-bit range of ourselves.
-  // Assume that the DuckStation binary will at max be 256MB. Therefore the max offset is
-  // +/- 256MB + round_up_pow2(size). This'll be 512MB for the JITs.
-  static const u8 base_ptr = 0;
-  const u8* base =
-    reinterpret_cast<const u8*>(Common::AlignDownPow2(reinterpret_cast<uintptr_t>(&base_ptr), HOST_PAGE_SIZE));
-  const u32 max_displacement = 0x80000000u - Common::NextPow2(256 * 1024 * 1024 + m_total_size);
-  const u8* max_address = ((base + max_displacement) < base) ?
-                            reinterpret_cast<const u8*>(std::numeric_limits<uintptr_t>::max()) :
-                            (base + max_displacement);
-  const u8* min_address = ((base - max_displacement) > base) ? nullptr : (base - max_displacement);
-  const u32 step = 64 * 1024 * 1024;
-  const u32 steps = static_cast<u32>(max_address - min_address) / step;
-  for (u32 offset = 0; offset < steps; offset++)
-  {
-    const u8* addr = max_address - (offset * step);
-    VERBOSE_LOG("Trying {} (base {}, offset {}, displacement 0x{:X})", static_cast<const void*>(addr),
-                static_cast<const void*>(base), offset, static_cast<ptrdiff_t>(addr - base));
-    if (TryAllocateAt(addr))
-      break;
-  }
-  if (m_code_ptr)
-  {
-    INFO_LOG("Allocated JIT buffer of size {} at {} (0x{:X} bytes away)", m_total_size, static_cast<void*>(m_code_ptr),
-             static_cast<ptrdiff_t>(m_code_ptr - base));
-  }
-  else
-  {
-    ERROR_LOG("Failed to allocate JIT buffer in range, expect crashes.");
-    if (!TryAllocateAt(nullptr))
-      return false;
-  }
-#else
-  if (!TryAllocateAt(nullptr))
-    return false;
-#endif
-
-  m_free_code_ptr = m_code_ptr;
-  m_code_size = size;
-  m_code_used = 0;
-
-  m_far_code_ptr = static_cast<u8*>(m_code_ptr) + size;
-  m_free_far_code_ptr = m_far_code_ptr;
-  m_far_code_size = far_code_size;
-  m_far_code_used = 0;
-
-  m_old_protection = 0;
-  m_owns_buffer = true;
-  return true;
-}
-
-bool JitCodeBuffer::TryAllocateAt(const void* addr)
-{
-#if defined(_WIN32)
-  m_code_ptr = static_cast<u8*>(VirtualAlloc(const_cast<void*>(addr), m_total_size,
-                                             addr ? (MEM_RESERVE | MEM_COMMIT) : MEM_COMMIT, PAGE_EXECUTE_READWRITE));
-  if (!m_code_ptr)
-  {
-    if (!addr)
-      ERROR_LOG("VirtualAlloc(RWX, {}) for internal buffer failed: {}", m_total_size, GetLastError());
-    return false;
-  }
-
-  return true;
-#elif defined(__APPLE__) && !defined(__aarch64__)
-  kern_return_t ret = mach_vm_allocate(mach_task_self(), reinterpret_cast<mach_vm_address_t*>(&addr), m_total_size,
-                                       addr ? VM_FLAGS_FIXED : VM_FLAGS_ANYWHERE);
-  if (ret != KERN_SUCCESS)
-  {
-    ERROR_LOG("mach_vm_allocate() returned {}", ret);
-    return false;
-  }
-
-  ret = mach_vm_protect(mach_task_self(), reinterpret_cast<mach_vm_address_t>(addr), m_total_size, false,
-                        VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE);
-  if (ret != KERN_SUCCESS)
-  {
-    ERROR_LOG("mach_vm_protect() returned {}", ret);
-    mach_vm_deallocate(mach_task_self(), reinterpret_cast<mach_vm_address_t>(addr), m_total_size);
-    return false;
-  }
-
-  m_code_ptr = static_cast<u8*>(const_cast<void*>(addr));
-  return true;
-#elif defined(__linux__) || defined(__ANDROID__) || defined(__APPLE__) || defined(__HAIKU__) || defined(__FreeBSD__)
-  int flags = MAP_PRIVATE | MAP_ANONYMOUS;
-#if defined(__linux__)
-  // Linux does the right thing, allows us to not disturb an existing mapping.
-  if (addr)
-    flags |= MAP_FIXED_NOREPLACE;
-#elif defined(__FreeBSD__)
-  // FreeBSD achieves the same with MAP_FIXED and MAP_EXCL.
-  if (addr)
-    flags |= MAP_FIXED | MAP_EXCL;
-#elif defined(__APPLE__)
-  // On ARM64, we need to use MAP_JIT, which means we can't use MAP_FIXED.
-  if (addr)
-    return false;
-  flags |= MAP_JIT;
-#endif
-
-  m_code_ptr =
-    static_cast<u8*>(mmap(const_cast<void*>(addr), m_total_size, PROT_READ | PROT_WRITE | PROT_EXEC, flags, -1, 0));
-  if (!m_code_ptr)
-  {
-    if (!addr)
-      ERROR_LOG("mmap(RWX, {}) for internal buffer failed: {}", m_total_size, errno);
-
-    return false;
-  }
-  else if (addr && m_code_ptr != addr)
-  {
-    if (munmap(m_code_ptr, m_total_size) != 0)
-      ERROR_LOG("Failed to munmap() incorrectly hinted allocation: {}", errno);
-    m_code_ptr = nullptr;
-    return false;
-  }
-
-  return true;
-#else
-  return false;
-#endif
-}
-
-bool JitCodeBuffer::Initialize(void* buffer, u32 size, u32 far_code_size /* = 0 */, u32 guard_size /* = 0 */)
-{
-  Destroy();
-
-  if ((far_code_size > 0 && guard_size >= far_code_size) || (far_code_size + (guard_size * 2)) > size)
-    return false;
-
-#if defined(_WIN32)
-  DWORD old_protect = 0;
-  if (!VirtualProtect(buffer, size, PAGE_EXECUTE_READWRITE, &old_protect))
-  {
-    ERROR_LOG("VirtualProtect(RWX) for external buffer failed: {}", GetLastError());
-    return false;
-  }
-
-  if (guard_size > 0)
-  {
-    DWORD old_guard_protect = 0;
-    u8* guard_at_end = (static_cast<u8*>(buffer) + size) - guard_size;
-    if (!VirtualProtect(buffer, guard_size, PAGE_NOACCESS, &old_guard_protect) ||
-        !VirtualProtect(guard_at_end, guard_size, PAGE_NOACCESS, &old_guard_protect))
-    {
-      ERROR_LOG("VirtualProtect(NOACCESS) for guard page failed: {}", GetLastError());
-      return false;
-    }
-  }
-
-  m_code_ptr = static_cast<u8*>(buffer);
-  m_old_protection = static_cast<u32>(old_protect);
-#elif defined(__linux__) || defined(__ANDROID__) || defined(__APPLE__) || defined(__HAIKU__) || defined(__FreeBSD__)
-  if (mprotect(buffer, size, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
-  {
-    ERROR_LOG("mprotect(RWX) for external buffer failed: {}", errno);
-    return false;
-  }
-
-  if (guard_size > 0)
-  {
-    u8* guard_at_end = (static_cast<u8*>(buffer) + size) - guard_size;
-    if (mprotect(buffer, guard_size, PROT_NONE) != 0 || mprotect(guard_at_end, guard_size, PROT_NONE) != 0)
-    {
-      ERROR_LOG("mprotect(NONE) for guard page failed: {}", errno);
-      return false;
-    }
-  }
-
-  // reasonable default?
-  m_code_ptr = static_cast<u8*>(buffer);
-  m_old_protection = PROT_READ | PROT_WRITE;
-#else
-  m_code_ptr = nullptr;
-#endif
-
-  if (!m_code_ptr)
-    return false;
 
   m_total_size = size;
-  m_free_code_ptr = m_code_ptr + guard_size;
+  m_code_ptr = static_cast<u8*>(ptr);
-  m_code_size = size - far_code_size - (guard_size * 2);
+  m_free_code_ptr = m_code_ptr;
+  m_code_size = size - far_code_size;
   m_code_used = 0;
 
-  m_far_code_ptr = static_cast<u8*>(m_code_ptr) + m_code_size;
+  m_far_code_size = far_code_size;
+  m_far_code_ptr = (far_code_size > 0) ? (static_cast<u8*>(m_code_ptr) + m_code_size) : nullptr;
   m_free_far_code_ptr = m_far_code_ptr;
-  m_far_code_size = far_code_size - guard_size;
   m_far_code_used = 0;
 
-  m_guard_size = guard_size;
+  MemMap::BeginCodeWrite();
-  m_owns_buffer = false;
-  return true;
-}
 
-void JitCodeBuffer::Destroy()
+  std::memset(m_code_ptr, 0, m_total_size);
-{
+  MemMap::FlushInstructionCache(m_code_ptr, m_total_size);
-  if (m_owns_buffer)
-  {
-#if defined(_WIN32)
-    if (!VirtualFree(m_code_ptr, 0, MEM_RELEASE))
-      ERROR_LOG("Failed to free code pointer {}", static_cast<void*>(m_code_ptr));
-#elif defined(__APPLE__) && !defined(__aarch64__)
-    const kern_return_t res =
-      mach_vm_deallocate(mach_task_self(), reinterpret_cast<mach_vm_address_t>(m_code_ptr), m_total_size);
-    if (res != KERN_SUCCESS)
-      ERROR_LOG("mach_vm_deallocate() failed: {}", res);
-#elif defined(__linux__) || defined(__ANDROID__) || defined(__APPLE__) || defined(__HAIKU__) || defined(__FreeBSD__)
-    if (munmap(m_code_ptr, m_total_size) != 0)
-      ERROR_LOG("Failed to free code pointer {}", static_cast<void*>(m_code_ptr));
-#endif
-  }
-  else if (m_code_ptr)
-  {
-#if defined(_WIN32)
-    DWORD old_protect = 0;
-    if (!VirtualProtect(m_code_ptr, m_total_size, m_old_protection, &old_protect))
-      ERROR_LOG("Failed to restore protection on {}", static_cast<void*>(m_code_ptr));
-#else
-    if (mprotect(m_code_ptr, m_total_size, m_old_protection) != 0)
-      ERROR_LOG("Failed to restore protection on {}", static_cast<void*>(m_code_ptr));
-#endif
-  }
 
-  m_code_ptr = nullptr;
+  MemMap::EndCodeWrite();
-  m_free_code_ptr = nullptr;
-  m_code_size = 0;
-  m_code_reserve_size = 0;
-  m_code_used = 0;
-  m_far_code_ptr = nullptr;
-  m_free_far_code_ptr = nullptr;
-  m_far_code_size = 0;
-  m_far_code_used = 0;
-  m_total_size = 0;
-  m_guard_size = 0;
-  m_old_protection = 0;
-  m_owns_buffer = false;
-}
-
-void JitCodeBuffer::ReserveCode(u32 size)
-{
-  Assert(m_code_used == 0);
-  Assert(size < m_code_size);
-
-  m_code_reserve_size += size;
-  m_free_code_ptr += size;
-  m_code_size -= size;
 }
 
 void JitCodeBuffer::CommitCode(u32 length)
@@ -303,10 +42,7 @@ void JitCodeBuffer::CommitCode(u32 length)
   if (length == 0)
     return;
 
-#if defined(CPU_ARCH_ARM32) || defined(CPU_ARCH_ARM64) || defined(CPU_ARCH_RISCV64)
+  MemMap::FlushInstructionCache(m_free_code_ptr, length);
-  // ARM instruction and data caches are not coherent, we need to flush after every block.
-  FlushInstructionCache(m_free_code_ptr, length);
-#endif
 
   Assert(length <= (m_code_size - m_code_used));
   m_free_code_ptr += length;
@@ -318,36 +54,13 @@ void JitCodeBuffer::CommitFarCode(u32 length)
   if (length == 0)
     return;
 
-#if defined(CPU_ARCH_ARM32) || defined(CPU_ARCH_ARM64) || defined(CPU_ARCH_RISCV64)
+  MemMap::FlushInstructionCache(m_free_far_code_ptr, length);
-  // ARM instruction and data caches are not coherent, we need to flush after every block.
-  FlushInstructionCache(m_free_far_code_ptr, length);
-#endif
 
   Assert(length <= (m_far_code_size - m_far_code_used));
   m_free_far_code_ptr += length;
   m_far_code_used += length;
 }
 
-void JitCodeBuffer::Reset()
-{
-  MemMap::BeginCodeWrite();
-
-  m_free_code_ptr = m_code_ptr + m_guard_size + m_code_reserve_size;
-  m_code_used = 0;
-  std::memset(m_free_code_ptr, 0, m_code_size);
-  FlushInstructionCache(m_free_code_ptr, m_code_size);
-
-  if (m_far_code_size > 0)
-  {
-    m_free_far_code_ptr = m_far_code_ptr;
-    m_far_code_used = 0;
-    std::memset(m_free_far_code_ptr, 0, m_far_code_size);
-    FlushInstructionCache(m_free_far_code_ptr, m_far_code_size);
-  }
-
-  MemMap::EndCodeWrite();
-}
-
 void JitCodeBuffer::Align(u32 alignment, u8 padding_value)
 {
   DebugAssert(Common::IsPow2(alignment));
@@ -359,14 +72,3 @@ void JitCodeBuffer::Align(u32 alignment, u8 padding_value)
   m_free_code_ptr += num_padding_bytes;
   m_code_used += num_padding_bytes;
 }
-
-void JitCodeBuffer::FlushInstructionCache(void* address, u32 size)
-{
-#if defined(_WIN32)
-  ::FlushInstructionCache(GetCurrentProcess(), address, size);
-#elif defined(__GNUC__) || defined(__clang__)
-  __builtin___clear_cache(reinterpret_cast<char*>(address), reinterpret_cast<char*>(address) + size);
-#else
-#error Unknown platform.
-#endif
-}

src/util/jit_code_buffer.h

@@ -8,17 +8,12 @@ class JitCodeBuffer
 {
 public:
   JitCodeBuffer();
-  JitCodeBuffer(u32 size, u32 far_code_size);
-  JitCodeBuffer(void* buffer, u32 size, u32 far_code_size, u32 guard_size);
   ~JitCodeBuffer();
 
   bool IsValid() const { return (m_code_ptr != nullptr); }
 
-  bool Allocate(u32 size = 64 * 1024 * 1024, u32 far_code_size = 0);
+  void Reset(void* ptr, u32 size, u32 far_code_size = 0);
-  bool Initialize(void* buffer, u32 size, u32 far_code_size = 0, u32 guard_size = 0);
+  
-  void Destroy();
-  void Reset();
-
   ALWAYS_INLINE u8* GetCodePointer() const { return m_code_ptr; }
   ALWAYS_INLINE u32 GetTotalSize() const { return m_total_size; }
   ALWAYS_INLINE float GetUsedPct() const
@@ -33,7 +28,6 @@ public:
 
   ALWAYS_INLINE u8* GetFreeCodePointer() const { return m_free_code_ptr; }
   ALWAYS_INLINE u32 GetFreeCodeSpace() const { return static_cast<u32>(m_code_size - m_code_used); }
-  void ReserveCode(u32 size);
   void CommitCode(u32 length);
 
   ALWAYS_INLINE u8* GetFreeFarCodePointer() const { return m_free_far_code_ptr; }
@@ -44,12 +38,7 @@ public:
   /// Assumes alignment is a power-of-two.
   void Align(u32 alignment, u8 padding_value);
 
-  /// Flushes the instruction cache on the host for the specified range.
-  static void FlushInstructionCache(void* address, u32 size);
-
 private:
-  bool TryAllocateAt(const void* addr);
-
   u8* m_code_ptr = nullptr;
   u8* m_free_code_ptr = nullptr;
   u32 m_code_size = 0;
@@ -62,7 +51,4 @@ private:
   u32 m_far_code_used = 0;
 
   u32 m_total_size = 0;
-  u32 m_guard_size = 0;
-  u32 m_old_protection = 0;
-  bool m_owns_buffer = false;
 };

src/util/platform_misc_win32.cpp

@@ -14,6 +14,7 @@
 #include <memory>
 
 #include "common/windows_headers.h"
+#include <Psapi.h>
 #include <WinSock2.h>
 #include <mmsystem.h>