merge from dev

2025-07-01 17:24:38 +03:00 · 2024-12-16 23:44:56 -08:00 · 2024-12-16 23:44:56 -08:00 · 806bf8ea7e
commit 806bf8ea7e
parent 577246d9ed 6ac636e2e2
28 changed files with 1055 additions and 471 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -14,6 +14,7 @@ option(MI_TRACK_VALGRIND    "Compile with Valgrind support (adds a small overhea
 option(MI_TRACK_ASAN        "Compile with address sanitizer support (adds a small overhead)" OFF)
 option(MI_TRACK_ETW         "Compile with Windows event tracing (ETW) support (adds a small overhead)" OFF)
 option(MI_USE_CXX           "Use the C++ compiler to compile the library (instead of the C compiler)" OFF)
+option(MI_OPT_ARCH          "Only for optimized builds: turn on architecture specific optimizations (for arm64: '-march=armv8.1-a' (2016))" ON)
 option(MI_SEE_ASM           "Generate assembly files" OFF)
 option(MI_OSX_INTERPOSE     "Use interpose to override standard malloc on macOS" ON)
 option(MI_OSX_ZONE          "Use malloc zone to override standard malloc on macOS" ON)
@ -73,16 +74,16 @@ else()
 endif()

 # -----------------------------------------------------------------------------
-# Convenience: set default build type depending on the build directory
+# Convenience: set default build type and compiler depending on the build directory
 # -----------------------------------------------------------------------------

 message(STATUS "")
 if (NOT CMAKE_BUILD_TYPE)
-  if ("${CMAKE_BINARY_DIR}" MATCHES ".*(D|d)ebug$" OR  MI_DEBUG_FULL)
-    message(STATUS "No build type selected, default to: Debug")
+  if ("${CMAKE_BINARY_DIR}" MATCHES ".*((D|d)ebug|asan|tsan|ubsan|valgrind)$" OR MI_DEBUG_FULL)
+    message(STATUS "No build type selected, default to 'Debug'")
    set(CMAKE_BUILD_TYPE "Debug")
  else()
-    message(STATUS "No build type selected, default to: Release")
+    message(STATUS "No build type selected, default to 'Release'")
    set(CMAKE_BUILD_TYPE "Release")
  endif()
 endif()
@ -92,7 +93,6 @@ if("${CMAKE_BINARY_DIR}" MATCHES ".*(S|s)ecure$")
  set(MI_SECURE "ON")
 endif()

-
 # -----------------------------------------------------------------------------
 # Process options
 # -----------------------------------------------------------------------------
@ -112,6 +112,14 @@ if(CMAKE_C_COMPILER_ID MATCHES "MSVC|Intel")
  set(MI_USE_CXX "ON")
 endif()

+if(CMAKE_BUILD_TYPE MATCHES "Release|RelWithDebInfo")
+  if (NOT MI_OPT_ARCH)
+    message(STATUS "Architecture specific optimizations are disabled (MI_OPT_ARCH=OFF)")
+  endif()
+else()
+  set(MI_OPT_ARCH OFF)
+endif()
+
 if(MI_OVERRIDE)
  message(STATUS "Override standard malloc (MI_OVERRIDE=ON)")
  if(APPLE)
@ -138,13 +146,7 @@ if(MI_OVERRIDE)
  endif()
 endif()

-if(WIN32)
-  if (MI_WIN_REDIRECT)
-    if (MSVC_C_ARCHITECTURE_ID MATCHES "ARM")
-      message(STATUS "Cannot use redirection on Windows ARM (MI_WIN_REDIRECT=OFF)")
-      set(MI_WIN_REDIRECT OFF)
-    endif()
-  endif()
+if(WIN32)  
  if (NOT MI_WIN_REDIRECT)
    # use a negative define for backward compatibility
    list(APPEND mi_defines MI_WIN_NOREDIRECT=1)
@ -319,16 +321,32 @@ if(MI_WIN_USE_FLS)
  list(APPEND mi_defines MI_WIN_USE_FLS=1)
 endif()

+# Determine architecture
+set(MI_OPT_ARCH_FLAGS "")
+set(MI_ARCH "unknown")
+if(APPLE)
+  list(FIND CMAKE_OSX_ARCHITECTURES "x86_64" x64_index)
+  list(FIND CMAKE_OSX_ARCHITECTURES "arm64" arm64_index)
+  if(x64_index GREATER_EQUAL 0)
+    set(MI_ARCH "x64")
+  elseif(arm64_index GREATER_EQUAL 0)
+    set(MI_ARCH "arm64")
+  endif()
+elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" OR CMAKE_GENERATOR_PLATFORM STREQUAL "x64")
+  set(MI_ARCH "x64")
+elseif(CMAKE_SYSTEM_PROCESSOR STREQUAL "aarch64" OR CMAKE_SYSTEM_PROCESSOR STREQUAL "ARM64" OR CMAKE_GENERATOR_PLATFORM STREQUAL "ARM64")
+  set(MI_ARCH "arm64")
+endif()

- # Check /proc/cpuinfo for an SV39 MMU and limit the virtual address bits.
- # (this will skip the aligned hinting in that case. Issue #939, #949)
- if (EXISTS /proc/cpuinfo)
-   file(STRINGS /proc/cpuinfo mi_sv39_mmu REGEX "^mmu[ \t]+:[ \t]+sv39$")
-   if (mi_sv39_mmu)
-     MESSAGE( STATUS "Set virtual address bits to 39 (SV39 MMU detected)" )
-     list(APPEND mi_defines MI_DEFAULT_VIRTUAL_ADDRESS_BITS=39)
-   endif()
- endif()
+# Check /proc/cpuinfo for an SV39 MMU and limit the virtual address bits.
+# (this will skip the aligned hinting in that case. Issue #939, #949)
+if (EXISTS /proc/cpuinfo)
+  file(STRINGS /proc/cpuinfo mi_sv39_mmu REGEX "^mmu[ \t]+:[ \t]+sv39$")
+  if (mi_sv39_mmu)
+    MESSAGE( STATUS "Set virtual address bits to 39 (SV39 MMU detected)" )
+    list(APPEND mi_defines MI_DEFAULT_VIRTUAL_ADDRESS_BITS=39)
+  endif()
+endif()

 # On Haiku use `-DCMAKE_INSTALL_PREFIX` instead, issue #788
 # if(CMAKE_SYSTEM_NAME MATCHES "Haiku")
@ -367,16 +385,31 @@ if(CMAKE_C_COMPILER_ID MATCHES "AppleClang|Clang|GNU|Intel" AND NOT CMAKE_SYSTEM
  if(MI_OVERRIDE)
    list(APPEND mi_cflags -fno-builtin-malloc)
  endif()
+  if(MI_OPT_ARCH)
+    if(MI_ARCH STREQUAL "arm64")
+      set(MI_OPT_ARCH_FLAGS "-march=armv8.1-a")         # fast atomics
+    endif()
+  endif()
 endif()

 if (MSVC AND MSVC_VERSION GREATER_EQUAL 1914)
  list(APPEND mi_cflags /Zc:__cplusplus)
+  if(MI_OPT_ARCH)
+    if(MI_ARCH STREQUAL "arm64")
+      set(MI_OPT_ARCH_FLAGS "/arch:armv8.1")           # fast atomics
+    endif()
+  endif()
 endif()

 if(MINGW)
  add_definitions(-D_WIN32_WINNT=0x600)
 endif()

+if(MI_OPT_ARCH_FLAGS)
+  list(APPEND mi_cflags ${MI_OPT_ARCH_FLAGS})
+  message(STATUS "Architecture specific optimization is enabled (with ${MI_OPT_ARCH_FLAGS}) (MI_OPT_ARCH=ON)")
+endif()
+
 # extra needed libraries

 # we prefer -l<lib> test over `find_library` as sometimes core libraries
@ -495,7 +528,9 @@ if(MI_BUILD_SHARED)
  )
  if(WIN32 AND MI_WIN_REDIRECT)
    # On windows, link and copy the mimalloc redirection dll too.
-    if(CMAKE_SIZEOF_VOID_P EQUAL 4)
+    if(MI_ARCH STREQUAL "arm64")
+      set(MIMALLOC_REDIRECT_SUFFIX "-arm64")
+    elseif(CMAKE_SIZEOF_VOID_P EQUAL 4)
      set(MIMALLOC_REDIRECT_SUFFIX "32")
    else()
      set(MIMALLOC_REDIRECT_SUFFIX "")
@ -617,6 +652,11 @@ endif()
 if (MI_OVERRIDE)
  if (MI_BUILD_SHARED)
    target_compile_definitions(mimalloc PRIVATE MI_MALLOC_OVERRIDE)
+    if (WIN32)
+      # on windows we should generate mimalloc-override.dll.
+      string(REPLACE "mimalloc" "mimalloc-override" mi_override_output_name ${mi_basename})
+      set_target_properties(mimalloc PROPERTIES OUTPUT_NAME ${mi_override_output_name})
+    endif()
  endif()
  if(NOT WIN32)
    # It is only possible to override malloc on Windows when building as a DLL.
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@ -284,7 +284,7 @@ jobs:
    displayName: CTest

 - job:
-  displayName: macOS 15 (Sequia)
+  displayName: macOS 15 (Sequoia)
  pool:
    vmImage:
      macOS-15
--- a/bin/mimalloc-redirect-arm64.dll
+++ b/bin/mimalloc-redirect-arm64.dll
--- a/bin/mimalloc-redirect-arm64.lib
+++ b/bin/mimalloc-redirect-arm64.lib
--- a/bin/minject-arm64.exe
+++ b/bin/minject-arm64.exe
--- a/bin/readme.md
+++ b/bin/readme.md
@ -11,11 +11,12 @@ There are four requirements to make the overriding work robustly:

 2. Link your program explicitly with `mimalloc-override.dll` library.
   To ensure the `mimalloc-override.dll` is loaded at run-time it is easiest to insert some
-    call to the mimalloc API in the `main` function, like `mi_version()`
-    (or use the `/INCLUDE:mi_version` switch on the linker). See the `mimalloc-override-test` project
-    for an example on how to use this. 
+  call to the mimalloc API in the `main` function, like `mi_version()`
+  (or use the `/INCLUDE:mi_version` switch on the linker, or
+  use `#pragma comment(linker, "/include:mi_version")` in some source file). 
+  See the `mimalloc-override-test` project for an example on how to use this. 

-3. The `mimalloc-redirect.dll` (or `mimalloc-redirect32.dll`) must be put
+3. The `mimalloc-redirect.dll` (x64) (or `mimalloc-redirect32.dll` (x86), or `mimalloc-redirect-arm64.dll` (arm64)) must be put
   in the same folder as the main `mimalloc-override.dll` at runtime (as it is a dependency of that DLL).
   The redirection DLL ensures that all calls to the C runtime malloc API get redirected to
   mimalloc functions (which reside in `mimalloc-override.dll`).
@ -40,7 +41,9 @@ if they are linked with the dynamic C runtime (`ucrtbase.dll`) -- just put the `
 into the import table (and put `mimalloc-redirect.dll` in the same folder)
 Such patching can be done for example with [CFF Explorer](https://ntcore.com/?page_id=388).

-The `minject` program can also do this from the command line, use `minject --help` for options:
+The `minject` program can also do this from the command line
+(or `minject32` for 32-bit PE files, or `minject-arm64` on arm64 Windows). 
+Use `minject --help` for options:

 ```
 > minject --help
--- a/ide/vs2022/mimalloc-override-test.vcxproj
+++ b/ide/vs2022/mimalloc-override-test.vcxproj
@ -1,10 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|ARM64">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
      <Platform>Win32</Platform>
    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM64">
+      <Configuration>Release</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Release|Win32">
      <Configuration>Release</Configuration>
      <Platform>Win32</Platform>
@ -42,12 +50,23 @@
    <UseDebugLibraries>true</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
    <ConfigurationType>Application</ConfigurationType>
    <UseDebugLibraries>false</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
    <WholeProgramOptimization>true</WholeProgramOptimization>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+  </PropertyGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
  <ImportGroup Label="ExtensionSettings">
  </ImportGroup>
@ -62,9 +81,15 @@
  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <PropertyGroup Label="UserMacros" />
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
@ -78,10 +103,18 @@
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
+  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
+  </PropertyGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -128,6 +161,30 @@
      </Command>
    </PostBuildEvent>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>..\..\include</AdditionalIncludeDirectories>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <ExceptionHandling>Sync</ExceptionHandling>
+      <CompileAs>Default</CompileAs>
+      <SupportJustMyCode>false</SupportJustMyCode>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <EntryPointSymbol>
+      </EntryPointSymbol>
+      <AdditionalDependencies>kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+    </Link>
+    <PostBuildEvent />
+    <PostBuildEvent>
+      <Command>
+      </Command>
+    </PostBuildEvent>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -176,6 +233,31 @@
      </Command>
    </PostBuildEvent>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>..\..\include</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>_MBCS;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+    </ClCompile>
+    <Link>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <SubSystem>Console</SubSystem>
+      <EntryPointSymbol>
+      </EntryPointSymbol>
+      <AdditionalDependencies>kernel32.lib;user32.lib;gdi32.lib;winspool.lib;comdlg32.lib;advapi32.lib;shell32.lib;ole32.lib;oleaut32.lib;uuid.lib;odbc32.lib;odbccp32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+    </Link>
+    <PostBuildEvent>
+      <Command>
+      </Command>
+    </PostBuildEvent>
+  </ItemDefinitionGroup>
  <ItemGroup>
    <ClCompile Include="..\..\test\main-override.cpp" />
  </ItemGroup>
--- a/ide/vs2022/mimalloc-override.vcxproj
+++ b/ide/vs2022/mimalloc-override.vcxproj
@ -1,10 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|ARM64">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
      <Platform>Win32</Platform>
    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM64">
+      <Configuration>Release</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Release|Win32">
      <Configuration>Release</Configuration>
      <Platform>Win32</Platform>
@ -41,11 +49,21 @@
    <UseDebugLibraries>true</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
    <ConfigurationType>DynamicLibrary</ConfigurationType>
    <UseDebugLibraries>false</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+  </PropertyGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
  <ImportGroup Label="ExtensionSettings">
  </ImportGroup>
@ -60,9 +78,15 @@
  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <PropertyGroup Label="UserMacros" />
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <OutDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
@ -82,12 +106,24 @@
    <TargetExt>.dll</TargetExt>
    <TargetName>mimalloc-override</TargetName>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <OutDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
+    <TargetExt>.dll</TargetExt>
+    <TargetName>mimalloc-override</TargetName>
+  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <OutDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
    <IntDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
    <TargetExt>.dll</TargetExt>
    <TargetName>mimalloc-override</TargetName>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <OutDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
+    <TargetExt>.dll</TargetExt>
+    <TargetName>mimalloc-override</TargetName>
+  </PropertyGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -144,6 +180,34 @@
      <Message>copy mimalloc-redirect.dll to the output directory</Message>
    </PostBuildEvent>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>MI_DEBUG=4;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <SupportJustMyCode>false</SupportJustMyCode>
+      <CompileAs>CompileAsCpp</CompileAs>
+    </ClCompile>
+    <Link>
+      <AdditionalDependencies>$(ProjectDir)\..\..\bin\mimalloc-redirect-arm64.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <IgnoreSpecificDefaultLibraries>
+      </IgnoreSpecificDefaultLibraries>
+      <ModuleDefinitionFile>
+      </ModuleDefinitionFile>
+      <LinkTimeCodeGeneration>Default</LinkTimeCodeGeneration>
+      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
+    </Link>
+    <PostBuildEvent>
+      <Command>COPY /Y "$(ProjectDir)..\..\bin\mimalloc-redirect-arm64.dll" "$(OutputPath)"</Command>
+    </PostBuildEvent>
+    <PostBuildEvent>
+      <Message>copy mimalloc-redirect-arm64.dll to the output directory</Message>
+    </PostBuildEvent>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -208,6 +272,39 @@
      <Message>copy mimalloc-redirect.dll to the output directory</Message>
    </PostBuildEvent>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
+      <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
+      <WholeProgramOptimization>false</WholeProgramOptimization>
+      <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
+      <CompileAs>CompileAsCpp</CompileAs>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <EnableEnhancedInstructionSet>CPUExtensionRequirementsARMv81</EnableEnhancedInstructionSet>
+    </ClCompile>
+    <Link>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalDependencies>$(ProjectDir)\..\..\bin\mimalloc-redirect-arm64.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <ModuleDefinitionFile>
+      </ModuleDefinitionFile>
+      <LinkTimeCodeGeneration>Default</LinkTimeCodeGeneration>
+      <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
+    </Link>
+    <PostBuildEvent>
+      <Command>COPY /Y "$(ProjectDir)..\..\bin\mimalloc-redirect-arm64.dll" "$(OutputPath)"</Command>
+    </PostBuildEvent>
+    <PostBuildEvent>
+      <Message>copy mimalloc-redirect-arm64.dll to the output directory</Message>
+    </PostBuildEvent>
+  </ItemDefinitionGroup>
  <ItemGroup>
    <ClInclude Include="$(ProjectDir)..\..\include\mimalloc.h" />
    <ClInclude Include="..\..\include\mimalloc-etw-gen.h" />
@ -226,13 +323,17 @@
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      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">false</ExcludedFromBuild>
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+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">false</ExcludedFromBuild>
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      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
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+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
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    <ClCompile Include="..\..\src\bitmap.c" />
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      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
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    <ClCompile Include="..\..\src\os.c" />
@ -260,7 +365,9 @@
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      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
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+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
    </ClCompile>
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    <ClCompile Include="..\..\src\random.c" />
--- a/ide/vs2022/mimalloc-test-api.vcxproj
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 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|ARM64">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
      <Platform>Win32</Platform>
    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM64">
+      <Configuration>Release</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Release|Win32">
      <Configuration>Release</Configuration>
      <Platform>Win32</Platform>
@ -42,12 +50,23 @@
    <UseDebugLibraries>true</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
    <ConfigurationType>Application</ConfigurationType>
    <UseDebugLibraries>false</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
    <WholeProgramOptimization>true</WholeProgramOptimization>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+  </PropertyGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
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@ -62,9 +81,15 @@
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    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
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@ -78,10 +103,18 @@
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    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
+  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
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  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -106,6 +139,18 @@
      <SubSystem>Console</SubSystem>
    </Link>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>..\..\include</AdditionalIncludeDirectories>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+    </Link>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -140,15 +185,35 @@
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+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <ClCompile>
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+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>..\..\include</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+    </ClCompile>
+    <Link>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <SubSystem>Console</SubSystem>
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  <ItemGroup>
    <ClCompile Include="..\..\test\test-api-fill.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
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    </ClCompile>
    <ClCompile Include="..\..\test\test-api.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">false</ExcludedFromBuild>
    </ClCompile>
  </ItemGroup>
  <ItemGroup>
--- a/ide/vs2022/mimalloc-test-stress.vcxproj
+++ b/ide/vs2022/mimalloc-test-stress.vcxproj
@ -1,10 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|ARM64">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
      <Platform>Win32</Platform>
    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM64">
+      <Configuration>Release</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Release|Win32">
      <Configuration>Release</Configuration>
      <Platform>Win32</Platform>
@ -42,12 +50,23 @@
    <UseDebugLibraries>true</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="Configuration">
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+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
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  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
    <ConfigurationType>Application</ConfigurationType>
    <UseDebugLibraries>false</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
    <WholeProgramOptimization>true</WholeProgramOptimization>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+  </PropertyGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
  <ImportGroup Label="ExtensionSettings">
  </ImportGroup>
@ -62,9 +81,15 @@
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    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
  <PropertyGroup Label="UserMacros" />
  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
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    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
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  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
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  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -106,6 +139,18 @@
      <SubSystem>Console</SubSystem>
    </Link>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>..\..\include</AdditionalIncludeDirectories>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+    </Link>
+  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -140,17 +185,37 @@
      <SubSystem>Console</SubSystem>
    </Link>
  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">
+    <ClCompile>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <ConformanceMode>true</ConformanceMode>
+      <AdditionalIncludeDirectories>..\..\include</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <EnableEnhancedInstructionSet>CPUExtensionRequirementsARMv81</EnableEnhancedInstructionSet>
+    </ClCompile>
+    <Link>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <SubSystem>Console</SubSystem>
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  <ItemGroup>
    <ClCompile Include="..\..\test\test-stress.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">false</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">false</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">false</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">false</ExcludedFromBuild>
    </ClCompile>
  </ItemGroup>
  <ItemGroup>
-    <ProjectReference Include="mimalloc-override.vcxproj">
-      <Project>{abb5eae7-b3e6-432e-b636-333449892ea7}</Project>
+    <ProjectReference Include="mimalloc.vcxproj">
+      <Project>{abb5eae7-b3e6-432e-b636-333449892ea6}</Project>
    </ProjectReference>
  </ItemGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
--- a/ide/vs2022/mimalloc-test.vcxproj
+++ b/ide/vs2022/mimalloc-test.vcxproj
@ -1,10 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|ARM64">
+      <Configuration>Debug</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
      <Platform>Win32</Platform>
    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|ARM64">
+      <Configuration>Release</Configuration>
+      <Platform>ARM64</Platform>
+    </ProjectConfiguration>
    <ProjectConfiguration Include="Release|Win32">
      <Configuration>Release</Configuration>
      <Platform>Win32</Platform>
@ -42,12 +50,23 @@
    <UseDebugLibraries>true</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
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  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
    <ConfigurationType>Application</ConfigurationType>
    <UseDebugLibraries>false</UseDebugLibraries>
    <PlatformToolset>v143</PlatformToolset>
    <WholeProgramOptimization>true</WholeProgramOptimization>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <PlatformToolset>v143</PlatformToolset>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+  </PropertyGroup>
  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
  <ImportGroup Label="ExtensionSettings">
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@ -62,9 +81,15 @@
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    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
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  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
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    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">
+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
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  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
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    <IntDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
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+    <OutDir>$(ProjectDir)..\..\out\msvc-$(Platform)\$(Configuration)\</OutDir>
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  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <WarningLevel>Level3</WarningLevel>
@ -108,6 +141,19 @@
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  </ItemDefinitionGroup>
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+      <LanguageStandard>stdcpp17</LanguageStandard>
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    <ClCompile>
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+      <PreprocessorDefinitions>_MBCS;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
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+      <SubSystem>Console</SubSystem>
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  <ItemGroup>
    <ProjectReference Include="mimalloc.vcxproj">
      <Project>{abb5eae7-b3e6-432e-b636-333449892ea6}</Project>
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-		Debug|x64 = Debug|x64
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--- a/ide/vs2022/mimalloc.vcxproj
+++ b/ide/vs2022/mimalloc.vcxproj
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 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
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    <ProjectConfiguration Include="Release|Win32">
      <Configuration>Release</Configuration>
      <Platform>Win32</Platform>
@ -42,12 +50,23 @@
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  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
  <ImportGroup Label="ExtensionSettings">
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@ -62,9 +81,15 @@
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    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
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  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'" Label="PropertySheets">
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@ -84,12 +109,24 @@
    <TargetExt>.lib</TargetExt>
    <TargetName>mimalloc-static</TargetName>
  </PropertyGroup>
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+    <TargetName>mimalloc-static</TargetName>
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  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
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    <IntDir>$(SolutionDir)..\..\out\msvc-$(Platform)\$(ProjectName)\$(Configuration)\</IntDir>
    <TargetExt>.lib</TargetExt>
    <TargetName>mimalloc-static</TargetName>
  </PropertyGroup>
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  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
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@ -136,6 +173,33 @@
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+      <PreprocessorDefinitions>MI_DEBUG=3;MI_GUARDED=0;%(PreprocessorDefinitions);</PreprocessorDefinitions>
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+    </ClCompile>
+    <Link>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <EntryPointSymbol>
+      </EntryPointSymbol>
+    </Link>
+    <PostBuildEvent>
+      <Command>
+      </Command>
+    </PostBuildEvent>
+    <Lib>
+      <AdditionalLibraryDirectories>
+      </AdditionalLibraryDirectories>
+      <AdditionalDependencies>
+      </AdditionalDependencies>
+    </Lib>
+  </ItemDefinitionGroup>
  <ItemGroup>
    <ClCompile Include="..\..\src\alloc-aligned.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">false</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">false</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">false</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">false</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\alloc-override.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\alloc-posix.c" />
    <ClCompile Include="..\..\src\alloc.c" />
    <ClCompile Include="..\..\src\arena-abandon.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\arena.c" />
    <ClCompile Include="..\..\src\bitmap.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">false</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\free.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\heap.c" />
    <ClCompile Include="..\..\src\init.c" />
@ -235,14 +344,18 @@
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\options.c" />
    <ClCompile Include="..\..\src\page-queue.c">
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug|ARM64'">true</ExcludedFromBuild>
      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|ARM64'">true</ExcludedFromBuild>
    </ClCompile>
    <ClCompile Include="..\..\src\page.c" />
    <ClCompile Include="..\..\src\random.c" />
--- a/include/mimalloc/internal.h
+++ b/include/mimalloc/internal.h
@ -53,90 +53,100 @@ terms of the MIT license. A copy of the license can be found in the file
 #define mi_decl_externc
 #endif

+// "libc.c"
+#include    <stdarg.h>
+void        _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args);
+void        _mi_snprintf(char* buf, size_t buflen, const char* fmt, ...);
+char        _mi_toupper(char c);
+int         _mi_strnicmp(const char* s, const char* t, size_t n);
+void        _mi_strlcpy(char* dest, const char* src, size_t dest_size);
+void        _mi_strlcat(char* dest, const char* src, size_t dest_size);
+size_t      _mi_strlen(const char* s);
+size_t      _mi_strnlen(const char* s, size_t max_len);
+bool        _mi_getenv(const char* name, char* result, size_t result_size);

 // "options.c"
-void       _mi_fputs(mi_output_fun* out, void* arg, const char* prefix, const char* message);
-void       _mi_fprintf(mi_output_fun* out, void* arg, const char* fmt, ...);
-void       _mi_warning_message(const char* fmt, ...);
-void       _mi_verbose_message(const char* fmt, ...);
-void       _mi_trace_message(const char* fmt, ...);
-void       _mi_options_init(void);
-long       _mi_option_get_fast(mi_option_t option);
-void       _mi_error_message(int err, const char* fmt, ...);
+void        _mi_fputs(mi_output_fun* out, void* arg, const char* prefix, const char* message);
+void        _mi_fprintf(mi_output_fun* out, void* arg, const char* fmt, ...);
+void        _mi_warning_message(const char* fmt, ...);
+void        _mi_verbose_message(const char* fmt, ...);
+void        _mi_trace_message(const char* fmt, ...);
+void        _mi_options_init(void);
+long        _mi_option_get_fast(mi_option_t option);
+void        _mi_error_message(int err, const char* fmt, ...);

 // random.c
-void       _mi_random_init(mi_random_ctx_t* ctx);
-void       _mi_random_init_weak(mi_random_ctx_t* ctx);
-void       _mi_random_reinit_if_weak(mi_random_ctx_t * ctx);
-void       _mi_random_split(mi_random_ctx_t* ctx, mi_random_ctx_t* new_ctx);
-uintptr_t  _mi_random_next(mi_random_ctx_t* ctx);
-uintptr_t  _mi_heap_random_next(mi_heap_t* heap);
-uintptr_t  _mi_os_random_weak(uintptr_t extra_seed);
+void        _mi_random_init(mi_random_ctx_t* ctx);
+void        _mi_random_init_weak(mi_random_ctx_t* ctx);
+void        _mi_random_reinit_if_weak(mi_random_ctx_t * ctx);
+void        _mi_random_split(mi_random_ctx_t* ctx, mi_random_ctx_t* new_ctx);
+uintptr_t   _mi_random_next(mi_random_ctx_t* ctx);
+uintptr_t   _mi_heap_random_next(mi_heap_t* heap);
+uintptr_t   _mi_os_random_weak(uintptr_t extra_seed);
 static inline uintptr_t _mi_random_shuffle(uintptr_t x);

 // init.c
 extern mi_decl_cache_align mi_stats_t       _mi_stats_main;
 extern mi_decl_cache_align const mi_page_t  _mi_page_empty;
-void       _mi_process_load(void);
+void        _mi_process_load(void);
 void mi_cdecl _mi_process_done(void);
-bool       _mi_is_redirected(void);
-bool       _mi_allocator_init(const char** message);
-void       _mi_allocator_done(void);
-bool       _mi_is_main_thread(void);
-size_t     _mi_current_thread_count(void);
-bool       _mi_preloading(void);           // true while the C runtime is not initialized yet
-void       _mi_thread_done(mi_heap_t* heap);
-void       _mi_thread_data_collect(void);
-void       _mi_tld_init(mi_tld_t* tld, mi_heap_t* bheap);
+bool        _mi_is_redirected(void);
+bool        _mi_allocator_init(const char** message);
+void        _mi_allocator_done(void);
+bool        _mi_is_main_thread(void);
+size_t      _mi_current_thread_count(void);
+bool        _mi_preloading(void);           // true while the C runtime is not initialized yet
+void        _mi_thread_done(mi_heap_t* heap);
+void        _mi_thread_data_collect(void);
+void        _mi_tld_init(mi_tld_t* tld, mi_heap_t* bheap);
 mi_threadid_t _mi_thread_id(void) mi_attr_noexcept;
 mi_heap_t*    _mi_heap_main_get(void);     // statically allocated main backing heap
 mi_subproc_t* _mi_subproc_from_id(mi_subproc_id_t subproc_id);
-void       _mi_heap_guarded_init(mi_heap_t* heap);
+void        _mi_heap_guarded_init(mi_heap_t* heap);

 // os.c
-void       _mi_os_init(void);                                            // called from process init
-void*      _mi_os_alloc(size_t size, mi_memid_t* memid, mi_stats_t* stats);
-void       _mi_os_free(void* p, size_t size, mi_memid_t memid, mi_stats_t* stats);
-void       _mi_os_free_ex(void* p, size_t size, bool still_committed, mi_memid_t memid, mi_stats_t* stats);
+void        _mi_os_init(void);                                            // called from process init
+void*       _mi_os_alloc(size_t size, mi_memid_t* memid);
+void        _mi_os_free(void* p, size_t size, mi_memid_t memid);
+void        _mi_os_free_ex(void* p, size_t size, bool still_committed, mi_memid_t memid);

-size_t     _mi_os_page_size(void);
-size_t     _mi_os_good_alloc_size(size_t size);
-bool       _mi_os_has_overcommit(void);
-bool       _mi_os_has_virtual_reserve(void);
+size_t      _mi_os_page_size(void);
+size_t      _mi_os_good_alloc_size(size_t size);
+bool        _mi_os_has_overcommit(void);
+bool        _mi_os_has_virtual_reserve(void);

-bool       _mi_os_purge(void* p, size_t size, mi_stats_t* stats);
-bool       _mi_os_reset(void* addr, size_t size, mi_stats_t* tld_stats);
-bool       _mi_os_commit(void* p, size_t size, bool* is_zero, mi_stats_t* stats);
-bool       _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats);
-bool       _mi_os_protect(void* addr, size_t size);
-bool       _mi_os_unprotect(void* addr, size_t size);
-bool       _mi_os_purge(void* p, size_t size, mi_stats_t* stats);
-bool       _mi_os_purge_ex(void* p, size_t size, bool allow_reset, mi_stats_t* stats);
+bool        _mi_os_reset(void* addr, size_t size);
+bool        _mi_os_commit(void* p, size_t size, bool* is_zero);
+bool        _mi_os_decommit(void* addr, size_t size);
+bool        _mi_os_protect(void* addr, size_t size);
+bool        _mi_os_unprotect(void* addr, size_t size);
+bool        _mi_os_purge(void* p, size_t size);
+bool        _mi_os_purge_ex(void* p, size_t size, bool allow_reset);

-void*      _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* stats);
-void*      _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* tld_stats);
+void*       _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid);
+void*       _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_memid_t* memid);

-void*      _mi_os_get_aligned_hint(size_t try_alignment, size_t size);
-bool       _mi_os_use_large_page(size_t size, size_t alignment);
-size_t     _mi_os_large_page_size(void);
+void*       _mi_os_get_aligned_hint(size_t try_alignment, size_t size);
+bool        _mi_os_use_large_page(size_t size, size_t alignment);
+size_t      _mi_os_large_page_size(void);

-void*      _mi_os_alloc_huge_os_pages(size_t pages, int numa_node, mi_msecs_t max_secs, size_t* pages_reserved, size_t* psize, mi_memid_t* memid);
+void*       _mi_os_alloc_huge_os_pages(size_t pages, int numa_node, mi_msecs_t max_secs, size_t* pages_reserved, size_t* psize, mi_memid_t* memid);

 // arena.c
 mi_arena_id_t _mi_arena_id_none(void);
-void       _mi_arena_free(void* p, size_t size, size_t still_committed_size, mi_memid_t memid, mi_stats_t* stats);
-void*      _mi_arena_alloc(size_t size, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld);
-void*      _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld);
-bool       _mi_arena_memid_is_suitable(mi_memid_t memid, mi_arena_id_t request_arena_id);
-bool       _mi_arena_contains(const void* p);
-void       _mi_arenas_collect(bool force_purge, mi_stats_t* stats);
-void       _mi_arena_unsafe_destroy_all(mi_stats_t* stats);
+void        _mi_arena_free(void* p, size_t size, size_t still_committed_size, mi_memid_t memid);
+void*       _mi_arena_alloc(size_t size, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid);
+void*       _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid);
+bool        _mi_arena_memid_is_suitable(mi_memid_t memid, mi_arena_id_t request_arena_id);
+bool        _mi_arena_contains(const void* p);
+void        _mi_arenas_collect(bool force_purge);
+void        _mi_arena_unsafe_destroy_all(void);

-bool       _mi_arena_segment_clear_abandoned(mi_segment_t* segment);
-void       _mi_arena_segment_mark_abandoned(mi_segment_t* segment);
+bool        _mi_arena_segment_clear_abandoned(mi_segment_t* segment);
+void        _mi_arena_segment_mark_abandoned(mi_segment_t* segment);

-void*      _mi_arena_meta_zalloc(size_t size, mi_memid_t* memid);
-void       _mi_arena_meta_free(void* p, mi_memid_t memid, size_t size);
+void*       _mi_arena_meta_zalloc(size_t size, mi_memid_t* memid);
+void        _mi_arena_meta_free(void* p, mi_memid_t memid, size_t size);

 typedef struct mi_arena_field_cursor_s { // abstract struct
  size_t         os_list_count;           // max entries to visit in the OS abandoned list
@ -152,20 +162,20 @@ mi_segment_t* _mi_arena_segment_clear_abandoned_next(mi_arena_field_cursor_t* pr
 void          _mi_arena_field_cursor_done(mi_arena_field_cursor_t* current);

 // "segment-map.c"
-void       _mi_segment_map_allocated_at(const mi_segment_t* segment);
-void       _mi_segment_map_freed_at(const mi_segment_t* segment);
+void        _mi_segment_map_allocated_at(const mi_segment_t* segment);
+void        _mi_segment_map_freed_at(const mi_segment_t* segment);

 // "segment.c"
-mi_page_t* _mi_segment_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment, mi_segments_tld_t* tld, mi_os_tld_t* os_tld);
+mi_page_t* _mi_segment_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment, mi_segments_tld_t* tld);
 void       _mi_segment_page_free(mi_page_t* page, bool force, mi_segments_tld_t* tld);
 void       _mi_segment_page_abandon(mi_page_t* page, mi_segments_tld_t* tld);
 bool       _mi_segment_try_reclaim_abandoned( mi_heap_t* heap, bool try_all, mi_segments_tld_t* tld);
-void       _mi_segment_collect(mi_segment_t* segment, bool force, mi_segments_tld_t* tld);
+void       _mi_segment_collect(mi_segment_t* segment, bool force);

 #if MI_HUGE_PAGE_ABANDON
-void       _mi_segment_huge_page_free(mi_segment_t* segment, mi_page_t* page, mi_block_t* block);
+void        _mi_segment_huge_page_free(mi_segment_t* segment, mi_page_t* page, mi_block_t* block);
 #else
-void       _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, mi_block_t* block);
+void        _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, mi_block_t* block);
 #endif

 uint8_t*   _mi_segment_page_start(const mi_segment_t* segment, const mi_page_t* page, size_t* page_size); // page start for any page
@ -175,42 +185,42 @@ bool       _mi_segment_attempt_reclaim(mi_heap_t* heap, mi_segment_t* segment);
 bool       _mi_segment_visit_blocks(mi_segment_t* segment, int heap_tag, bool visit_blocks, mi_block_visit_fun* visitor, void* arg);

 // "page.c"
-void*      _mi_malloc_generic(mi_heap_t* heap, size_t size, bool zero, size_t huge_alignment)  mi_attr_noexcept mi_attr_malloc;
+void*       _mi_malloc_generic(mi_heap_t* heap, size_t size, bool zero, size_t huge_alignment)  mi_attr_noexcept mi_attr_malloc;

-void       _mi_page_retire(mi_page_t* page) mi_attr_noexcept;                  // free the page if there are no other pages with many free blocks
-void       _mi_page_unfull(mi_page_t* page);
-void       _mi_page_free(mi_page_t* page, mi_page_queue_t* pq, bool force);   // free the page
-void       _mi_page_abandon(mi_page_t* page, mi_page_queue_t* pq);            // abandon the page, to be picked up by another thread...
-void       _mi_page_force_abandon(mi_page_t* page);
+void        _mi_page_retire(mi_page_t* page) mi_attr_noexcept;                  // free the page if there are no other pages with many free blocks
+void        _mi_page_unfull(mi_page_t* page);
+void        _mi_page_free(mi_page_t* page, mi_page_queue_t* pq, bool force);   // free the page
+void        _mi_page_abandon(mi_page_t* page, mi_page_queue_t* pq);            // abandon the page, to be picked up by another thread...
+void        _mi_page_force_abandon(mi_page_t* page);

-void       _mi_heap_delayed_free_all(mi_heap_t* heap);
-bool       _mi_heap_delayed_free_partial(mi_heap_t* heap);
-void       _mi_heap_collect_retired(mi_heap_t* heap, bool force);
+void        _mi_heap_delayed_free_all(mi_heap_t* heap);
+bool        _mi_heap_delayed_free_partial(mi_heap_t* heap);
+void        _mi_heap_collect_retired(mi_heap_t* heap, bool force);

-void       _mi_page_use_delayed_free(mi_page_t* page, mi_delayed_t delay, bool override_never);
-bool       _mi_page_try_use_delayed_free(mi_page_t* page, mi_delayed_t delay, bool override_never);
-size_t     _mi_page_queue_append(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_queue_t* append);
-void       _mi_deferred_free(mi_heap_t* heap, bool force);
+void        _mi_page_use_delayed_free(mi_page_t* page, mi_delayed_t delay, bool override_never);
+bool        _mi_page_try_use_delayed_free(mi_page_t* page, mi_delayed_t delay, bool override_never);
+size_t      _mi_page_queue_append(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_queue_t* append);
+void        _mi_deferred_free(mi_heap_t* heap, bool force);

-void       _mi_page_free_collect(mi_page_t* page,bool force);
-void       _mi_page_reclaim(mi_heap_t* heap, mi_page_t* page);   // callback from segments
+void        _mi_page_free_collect(mi_page_t* page,bool force);
+void        _mi_page_reclaim(mi_heap_t* heap, mi_page_t* page);   // callback from segments

-size_t     _mi_bin_size(uint8_t bin);           // for stats
-uint8_t    _mi_bin(size_t size);                // for stats
+size_t      _mi_bin_size(uint8_t bin);           // for stats
+uint8_t     _mi_bin(size_t size);                // for stats

 // "heap.c"
-void       _mi_heap_init(mi_heap_t* heap, mi_tld_t* tld, mi_arena_id_t arena_id, bool noreclaim, uint8_t tag);
-void       _mi_heap_destroy_pages(mi_heap_t* heap);
-void       _mi_heap_collect_abandon(mi_heap_t* heap);
-void       _mi_heap_set_default_direct(mi_heap_t* heap);
-bool       _mi_heap_memid_is_suitable(mi_heap_t* heap, mi_memid_t memid);
-void       _mi_heap_unsafe_destroy_all(void);
-mi_heap_t* _mi_heap_by_tag(mi_heap_t* heap, uint8_t tag);
-void       _mi_heap_area_init(mi_heap_area_t* area, mi_page_t* page);
-bool       _mi_heap_area_visit_blocks(const mi_heap_area_t* area, mi_page_t* page, mi_block_visit_fun* visitor, void* arg);
+void        _mi_heap_init(mi_heap_t* heap, mi_tld_t* tld, mi_arena_id_t arena_id, bool noreclaim, uint8_t tag);
+void        _mi_heap_destroy_pages(mi_heap_t* heap);
+void        _mi_heap_collect_abandon(mi_heap_t* heap);
+void        _mi_heap_set_default_direct(mi_heap_t* heap);
+bool        _mi_heap_memid_is_suitable(mi_heap_t* heap, mi_memid_t memid);
+void        _mi_heap_unsafe_destroy_all(void);
+mi_heap_t*  _mi_heap_by_tag(mi_heap_t* heap, uint8_t tag);
+void        _mi_heap_area_init(mi_heap_area_t* area, mi_page_t* page);
+bool        _mi_heap_area_visit_blocks(const mi_heap_area_t* area, mi_page_t* page, mi_block_visit_fun* visitor, void* arg);

 // "stats.c"
-void       _mi_stats_done(mi_stats_t* stats);
+void        _mi_stats_done(mi_stats_t* stats);
 mi_msecs_t  _mi_clock_now(void);
 mi_msecs_t  _mi_clock_end(mi_msecs_t start);
 mi_msecs_t  _mi_clock_start(void);
@ -227,18 +237,6 @@ bool        _mi_free_delayed_block(mi_block_t* block);
 void        _mi_free_generic(mi_segment_t* segment, mi_page_t* page, bool is_local, void* p) mi_attr_noexcept;  // for runtime integration
 void        _mi_padding_shrink(const mi_page_t* page, const mi_block_t* block, const size_t min_size);

-// "libc.c"
-#include    <stdarg.h>
-void        _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args);
-void        _mi_snprintf(char* buf, size_t buflen, const char* fmt, ...);
-char        _mi_toupper(char c);
-int         _mi_strnicmp(const char* s, const char* t, size_t n);
-void        _mi_strlcpy(char* dest, const char* src, size_t dest_size);
-void        _mi_strlcat(char* dest, const char* src, size_t dest_size);
-size_t      _mi_strlen(const char* s);
-size_t      _mi_strnlen(const char* s, size_t max_len);
-bool        _mi_getenv(const char* name, char* result, size_t result_size);
-
 #if MI_DEBUG>1
 bool        _mi_page_is_valid(mi_page_t* page);
 #endif
@ -890,13 +888,13 @@ static inline uintptr_t _mi_random_shuffle(uintptr_t x) {
 // Optimize numa node access for the common case (= one node)
 // -------------------------------------------------------------------

-int    _mi_os_numa_node_get(mi_os_tld_t* tld);
+int    _mi_os_numa_node_get(void);
 size_t _mi_os_numa_node_count_get(void);

 extern _Atomic(size_t) _mi_numa_node_count;
-static inline int _mi_os_numa_node(mi_os_tld_t* tld) {
+static inline int _mi_os_numa_node(void) {
  if mi_likely(mi_atomic_load_relaxed(&_mi_numa_node_count) == 1) { return 0; }
-  else return _mi_os_numa_node_get(tld);
+  else return _mi_os_numa_node_get();
 }
 static inline size_t _mi_os_numa_node_count(void) {
  const size_t count = mi_atomic_load_relaxed(&_mi_numa_node_count);
@ -958,16 +956,18 @@ static inline size_t mi_ctz(uintptr_t x) {
 }

 #else
-static inline size_t mi_ctz32(uint32_t x) {
+
+static inline size_t mi_ctz_generic32(uint32_t x) {
  // de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf>
-  static const unsigned char debruijn[32] = {
+  static const uint8_t debruijn[32] = {
    0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
    31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
  };
  if (x==0) return 32;
-  return debruijn[((x & -(int32_t)x) * 0x077CB531UL) >> 27];
+  return debruijn[(uint32_t)((x & -(int32_t)x) * (uint32_t)(0x077CB531U)) >> 27];
 }
-static inline size_t mi_clz32(uint32_t x) {
+
+static inline size_t mi_clz_generic32(uint32_t x) {
  // de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf>
  static const uint8_t debruijn[32] = {
    31, 22, 30, 21, 18, 10, 29, 2, 20, 17, 15, 13, 9, 6, 28, 1,
@ -979,28 +979,37 @@ static inline size_t mi_clz32(uint32_t x) {
  x |= x >> 4;
  x |= x >> 8;
  x |= x >> 16;
-  return debruijn[(uint32_t)(x * 0x07C4ACDDUL) >> 27];
+  return debruijn[(uint32_t)(x * (uint32_t)(0x07C4ACDDU)) >> 27];
 }

-static inline size_t mi_clz(uintptr_t x) {
-  if (x==0) return MI_INTPTR_BITS;
-#if (MI_INTPTR_BITS <= 32)
-  return mi_clz32((uint32_t)x);
-#else
-  size_t count = mi_clz32((uint32_t)(x >> 32));
-  if (count < 32) return count;
-  return (32 + mi_clz32((uint32_t)x));
-#endif
+static inline size_t mi_ctz(size_t x) {
+  if (x==0) return MI_SIZE_BITS;
+  #if (MI_SIZE_BITS <= 32)
+    return mi_ctz_generic32((uint32_t)x);
+  #else
+    const uint32_t lo = (uint32_t)x;
+    if (lo != 0) {
+      return mi_ctz_generic32(lo);
+    }
+    else {
+      return (32 + mi_ctz_generic32((uint32_t)(x>>32)));
+    }
+  #endif
 }
-static inline size_t mi_ctz(uintptr_t x) {
-  if (x==0) return MI_INTPTR_BITS;
-#if (MI_INTPTR_BITS <= 32)
-  return mi_ctz32((uint32_t)x);
-#else
-  size_t count = mi_ctz32((uint32_t)x);
-  if (count < 32) return count;
-  return (32 + mi_ctz32((uint32_t)(x>>32)));
-#endif
+
+static inline size_t mi_clz(size_t x) {
+  if (x==0) return MI_SIZE_BITS;
+  #if (MI_SIZE_BITS <= 32)
+    return mi_clz_generic32((uint32_t)x);
+  #else
+    const uint32_t hi = (uint32_t)(x>>32);
+    if (hi != 0) {
+      return mi_clz_generic32(hi);
+    }
+    else {
+      return 32 + mi_clz_generic32((uint32_t)x);
+    }
+  #endif
 }

 #endif
--- a/include/mimalloc/types.h
+++ b/include/mimalloc/types.h
@ -717,13 +717,6 @@ typedef struct mi_span_queue_s {

 #define MI_SEGMENT_BIN_MAX (35)     // 35 == mi_segment_bin(MI_SLICES_PER_SEGMENT)

-// OS thread local data
-typedef struct mi_os_tld_s {
-  size_t                region_idx;   // start point for next allocation
-  mi_stats_t*           stats;        // points to tld stats
-} mi_os_tld_t;
-
-
 // Segments thread local data
 typedef struct mi_segments_tld_s {
  mi_span_queue_t     spans[MI_SEGMENT_BIN_MAX+1];  // free slice spans inside segments
@ -734,7 +727,6 @@ typedef struct mi_segments_tld_s {
  size_t              reclaim_count;// number of reclaimed (abandoned) segments
  mi_subproc_t*       subproc;      // sub-process this thread belongs to.
  mi_stats_t*         stats;        // points to tld stats
-  mi_os_tld_t*        os;           // points to os tld
 } mi_segments_tld_t;

 // Thread local data
@ -744,7 +736,6 @@ struct mi_tld_s {
  mi_heap_t*          heap_backing;  // backing heap of this thread (cannot be deleted)
  mi_heap_t*          heaps;         // list of heaps in this thread (so we can abandon all when the thread terminates)
  mi_segments_tld_t   segments;      // segment tld
-  mi_os_tld_t         os;            // os tld
  mi_stats_t          stats;         // statistics
 };

--- a/src/alloc-aligned.c
+++ b/src/alloc-aligned.c
@ -39,9 +39,10 @@ static mi_decl_restrict void* mi_heap_malloc_guarded_aligned(mi_heap_t* heap, si

 static void* mi_heap_malloc_zero_no_guarded(mi_heap_t* heap, size_t size, bool zero) {
  const size_t rate = heap->guarded_sample_rate;
-  heap->guarded_sample_rate = 0;
+  // only write if `rate!=0` so we don't write to the constant `_mi_heap_empty`
+  if (rate != 0) { heap->guarded_sample_rate = 0; }
  void* p = _mi_heap_malloc_zero(heap, size, zero);
-  heap->guarded_sample_rate = rate;
+  if (rate != 0) { heap->guarded_sample_rate = rate; }
  return p;
 }
 #else
--- a/src/arena.c
+++ b/src/arena.c
@ -190,7 +190,7 @@ void* _mi_arena_meta_zalloc(size_t size, mi_memid_t* memid) {
  if (p != NULL) return p;

  // or fall back to the OS
-  p = _mi_os_alloc(size, memid, &_mi_stats_main);
+  p = _mi_os_alloc(size, memid);
  if (p == NULL) return NULL;

  // zero the OS memory if needed
@ -203,7 +203,7 @@ void* _mi_arena_meta_zalloc(size_t size, mi_memid_t* memid) {

 void _mi_arena_meta_free(void* p, mi_memid_t memid, size_t size) {
  if (mi_memkind_is_os(memid.memkind)) {
-    _mi_os_free(p, size, memid, &_mi_stats_main);
+    _mi_os_free(p, size, memid);
  }
  else {
    mi_assert(memid.memkind == MI_MEM_STATIC);
@ -220,10 +220,10 @@ void* mi_arena_block_start(mi_arena_t* arena, mi_bitmap_index_t bindex) {
 ----------------------------------------------------------- */

 // claim the `blocks_inuse` bits
-static bool mi_arena_try_claim(mi_arena_t* arena, size_t blocks, mi_bitmap_index_t* bitmap_idx, mi_stats_t* stats)
+static bool mi_arena_try_claim(mi_arena_t* arena, size_t blocks, mi_bitmap_index_t* bitmap_idx)
 {
  size_t idx = 0; // mi_atomic_load_relaxed(&arena->search_idx);  // start from last search; ok to be relaxed as the exact start does not matter
-  if (_mi_bitmap_try_find_from_claim_across(arena->blocks_inuse, arena->field_count, idx, blocks, bitmap_idx, stats)) {
+  if (_mi_bitmap_try_find_from_claim_across(arena->blocks_inuse, arena->field_count, idx, blocks, bitmap_idx)) {
    mi_atomic_store_relaxed(&arena->search_idx, mi_bitmap_index_field(*bitmap_idx));  // start search from found location next time around
    return true;
  };
@ -236,13 +236,13 @@ static bool mi_arena_try_claim(mi_arena_t* arena, size_t blocks, mi_bitmap_index
 ----------------------------------------------------------- */

 static mi_decl_noinline void* mi_arena_try_alloc_at(mi_arena_t* arena, size_t arena_index, size_t needed_bcount,
-                                                    bool commit, mi_memid_t* memid, mi_os_tld_t* tld)
+                                                    bool commit, mi_memid_t* memid)
 {
  MI_UNUSED(arena_index);
  mi_assert_internal(mi_arena_id_index(arena->id) == arena_index);

  mi_bitmap_index_t bitmap_index;
-  if (!mi_arena_try_claim(arena, needed_bcount, &bitmap_index, tld->stats)) return NULL;
+  if (!mi_arena_try_claim(arena, needed_bcount, &bitmap_index)) return NULL;

  // claimed it!
  void* p = mi_arena_block_start(arena, bitmap_index);
@ -272,7 +272,7 @@ static mi_decl_noinline void* mi_arena_try_alloc_at(mi_arena_t* arena, size_t ar
    _mi_bitmap_claim_across(arena->blocks_committed, arena->field_count, needed_bcount, bitmap_index, &any_uncommitted);
    if (any_uncommitted) {
      bool commit_zero = false;
-      if (!_mi_os_commit(p, mi_arena_block_size(needed_bcount), &commit_zero, tld->stats)) {
+      if (!_mi_os_commit(p, mi_arena_block_size(needed_bcount), &commit_zero)) {
        memid->initially_committed = false;
      }
      else {
@ -290,7 +290,7 @@ static mi_decl_noinline void* mi_arena_try_alloc_at(mi_arena_t* arena, size_t ar

 // allocate in a speficic arena
 static void* mi_arena_try_alloc_at_id(mi_arena_id_t arena_id, bool match_numa_node, int numa_node, size_t size, size_t alignment,
-                                       bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld )
+                                       bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid )
 {
  MI_UNUSED_RELEASE(alignment);
  mi_assert(alignment <= MI_SEGMENT_ALIGN);
@ -311,7 +311,7 @@ static void* mi_arena_try_alloc_at_id(mi_arena_id_t arena_id, bool match_numa_no
  }

  // try to allocate
-  void* p = mi_arena_try_alloc_at(arena, arena_index, bcount, commit, memid, tld);
+  void* p = mi_arena_try_alloc_at(arena, arena_index, bcount, commit, memid);
  mi_assert_internal(p == NULL || _mi_is_aligned(p, alignment));
  return p;
 }
@ -320,7 +320,7 @@ static void* mi_arena_try_alloc_at_id(mi_arena_id_t arena_id, bool match_numa_no
 // allocate from an arena with fallback to the OS
 static mi_decl_noinline void* mi_arena_try_alloc(int numa_node, size_t size, size_t alignment,
                                                  bool commit, bool allow_large,
-                                                  mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld )
+                                                  mi_arena_id_t req_arena_id, mi_memid_t* memid )
 {
  MI_UNUSED(alignment);
  mi_assert_internal(alignment <= MI_SEGMENT_ALIGN);
@ -330,21 +330,21 @@ static mi_decl_noinline void* mi_arena_try_alloc(int numa_node, size_t size, siz
  if (req_arena_id != _mi_arena_id_none()) {
    // try a specific arena if requested
    if (mi_arena_id_index(req_arena_id) < max_arena) {
-      void* p = mi_arena_try_alloc_at_id(req_arena_id, true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld);
+      void* p = mi_arena_try_alloc_at_id(req_arena_id, true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid);
      if (p != NULL) return p;
    }
  }
  else {
    // try numa affine allocation
    for (size_t i = 0; i < max_arena; i++) {
-      void* p = mi_arena_try_alloc_at_id(mi_arena_id_create(i), true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld);
+      void* p = mi_arena_try_alloc_at_id(mi_arena_id_create(i), true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid);
      if (p != NULL) return p;
    }

    // try from another numa node instead..
    if (numa_node >= 0) {  // if numa_node was < 0 (no specific affinity requested), all arena's have been tried already
      for (size_t i = 0; i < max_arena; i++) {
-        void* p = mi_arena_try_alloc_at_id(mi_arena_id_create(i), false /* only proceed if not numa local */, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld);
+        void* p = mi_arena_try_alloc_at_id(mi_arena_id_create(i), false /* only proceed if not numa local */, numa_node, size, alignment, commit, allow_large, req_arena_id, memid);
        if (p != NULL) return p;
      }
    }
@ -389,18 +389,18 @@ static bool mi_arena_reserve(size_t req_size, bool allow_large, mi_arena_id_t re


 void* _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large,
-                              mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld)
+                              mi_arena_id_t req_arena_id, mi_memid_t* memid)
 {
-  mi_assert_internal(memid != NULL && tld != NULL);
+  mi_assert_internal(memid != NULL);
  mi_assert_internal(size > 0);
  *memid = _mi_memid_none();

-  const int numa_node = _mi_os_numa_node(tld); // current numa node
+  const int numa_node = _mi_os_numa_node(); // current numa node

  // try to allocate in an arena if the alignment is small enough and the object is not too small (as for heap meta data)
  if (!mi_option_is_enabled(mi_option_disallow_arena_alloc) || req_arena_id != _mi_arena_id_none()) {  // is arena allocation allowed?
    if (size >= MI_ARENA_MIN_OBJ_SIZE && alignment <= MI_SEGMENT_ALIGN && align_offset == 0) {
-      void* p = mi_arena_try_alloc(numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld);
+      void* p = mi_arena_try_alloc(numa_node, size, alignment, commit, allow_large, req_arena_id, memid);
      if (p != NULL) return p;

      // otherwise, try to first eagerly reserve a new arena
@ -409,7 +409,7 @@ void* _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset
        if (mi_arena_reserve(size, allow_large, req_arena_id, &arena_id)) {
          // and try allocate in there
          mi_assert_internal(req_arena_id == _mi_arena_id_none());
-          p = mi_arena_try_alloc_at_id(arena_id, true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid, tld);
+          p = mi_arena_try_alloc_at_id(arena_id, true, numa_node, size, alignment, commit, allow_large, req_arena_id, memid);
          if (p != NULL) return p;
        }
      }
@ -424,16 +424,16 @@ void* _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset

  // finally, fall back to the OS
  if (align_offset > 0) {
-    return _mi_os_alloc_aligned_at_offset(size, alignment, align_offset, commit, allow_large, memid, tld->stats);
+    return _mi_os_alloc_aligned_at_offset(size, alignment, align_offset, commit, allow_large, memid);
  }
  else {
-    return _mi_os_alloc_aligned(size, alignment, commit, allow_large, memid, tld->stats);
+    return _mi_os_alloc_aligned(size, alignment, commit, allow_large, memid);
  }
 }

-void* _mi_arena_alloc(size_t size, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld)
+void* _mi_arena_alloc(size_t size, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid)
 {
-  return _mi_arena_alloc_aligned(size, MI_ARENA_BLOCK_SIZE, 0, commit, allow_large, req_arena_id, memid, tld);
+  return _mi_arena_alloc_aligned(size, MI_ARENA_BLOCK_SIZE, 0, commit, allow_large, req_arena_id, memid);
 }


@ -459,7 +459,7 @@ static long mi_arena_purge_delay(void) {

 // reset or decommit in an arena and update the committed/decommit bitmaps
 // assumes we own the area (i.e. blocks_in_use is claimed by us)
-static void mi_arena_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks, mi_stats_t* stats) {
+static void mi_arena_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks) {
  mi_assert_internal(arena->blocks_committed != NULL);
  mi_assert_internal(arena->blocks_purge != NULL);
  mi_assert_internal(!arena->memid.is_pinned);
@ -468,7 +468,7 @@ static void mi_arena_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks,
  bool needs_recommit;
  if (_mi_bitmap_is_claimed_across(arena->blocks_committed, arena->field_count, blocks, bitmap_idx)) {
    // all blocks are committed, we can purge freely
-    needs_recommit = _mi_os_purge(p, size, stats);
+    needs_recommit = _mi_os_purge(p, size);
  }
  else {
    // some blocks are not committed -- this can happen when a partially committed block is freed
@ -476,7 +476,7 @@ static void mi_arena_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks,
    // we need to ensure we do not try to reset (as that may be invalid for uncommitted memory),
    // and also undo the decommit stats (as it was already adjusted)
    mi_assert_internal(mi_option_is_enabled(mi_option_purge_decommits));
-    needs_recommit = _mi_os_purge_ex(p, size, false /* allow reset? */, stats);
+    needs_recommit = _mi_os_purge_ex(p, size, false /* allow reset? */);
    if (needs_recommit) { _mi_stat_increase(&_mi_stats_main.committed, size); }
  }

@ -490,14 +490,14 @@ static void mi_arena_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks,

 // Schedule a purge. This is usually delayed to avoid repeated decommit/commit calls.
 // Note: assumes we (still) own the area as we may purge immediately
-static void mi_arena_schedule_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks, mi_stats_t* stats) {
+static void mi_arena_schedule_purge(mi_arena_t* arena, size_t bitmap_idx, size_t blocks) {
  mi_assert_internal(arena->blocks_purge != NULL);
  const long delay = mi_arena_purge_delay();
  if (delay < 0) return;  // is purging allowed at all?

  if (_mi_preloading() || delay == 0) {
    // decommit directly
-    mi_arena_purge(arena, bitmap_idx, blocks, stats);
+    mi_arena_purge(arena, bitmap_idx, blocks);
  }
  else {
    // schedule decommit
@ -515,7 +515,7 @@ static void mi_arena_schedule_purge(mi_arena_t* arena, size_t bitmap_idx, size_t
 // purge a range of blocks
 // return true if the full range was purged.
 // assumes we own the area (i.e. blocks_in_use is claimed by us)
-static bool mi_arena_purge_range(mi_arena_t* arena, size_t idx, size_t startidx, size_t bitlen, size_t purge, mi_stats_t* stats) {
+static bool mi_arena_purge_range(mi_arena_t* arena, size_t idx, size_t startidx, size_t bitlen, size_t purge) {
  const size_t endidx = startidx + bitlen;
  size_t bitidx = startidx;
  bool all_purged = false;
@ -528,7 +528,7 @@ static bool mi_arena_purge_range(mi_arena_t* arena, size_t idx, size_t startidx,
    if (count > 0) {
      // found range to be purged
      const mi_bitmap_index_t range_idx = mi_bitmap_index_create(idx, bitidx);
-      mi_arena_purge(arena, range_idx, count, stats);
+      mi_arena_purge(arena, range_idx, count);
      if (count == bitlen) {
        all_purged = true;
      }
@ -539,7 +539,7 @@ static bool mi_arena_purge_range(mi_arena_t* arena, size_t idx, size_t startidx,
 }

 // returns true if anything was purged
-static bool mi_arena_try_purge(mi_arena_t* arena, mi_msecs_t now, bool force, mi_stats_t* stats)
+static bool mi_arena_try_purge(mi_arena_t* arena, mi_msecs_t now, bool force)
 {
  if (arena->memid.is_pinned || arena->blocks_purge == NULL) return false;
  mi_msecs_t expire = mi_atomic_loadi64_relaxed(&arena->purge_expire);
@ -575,7 +575,7 @@ static bool mi_arena_try_purge(mi_arena_t* arena, mi_msecs_t now, bool force, mi
        if (bitlen > 0) {
          // read purge again now that we have the in_use bits
          purge = mi_atomic_load_acquire(&arena->blocks_purge[i]);
-          if (!mi_arena_purge_range(arena, i, bitidx, bitlen, purge, stats)) {
+          if (!mi_arena_purge_range(arena, i, bitidx, bitlen, purge)) {
            full_purge = false;
          }
          any_purged = true;
@ -595,7 +595,7 @@ static bool mi_arena_try_purge(mi_arena_t* arena, mi_msecs_t now, bool force, mi
  return any_purged;
 }

-static void mi_arenas_try_purge( bool force, bool visit_all, mi_stats_t* stats ) {
+static void mi_arenas_try_purge( bool force, bool visit_all ) {
  if (_mi_preloading() || mi_arena_purge_delay() <= 0) return;  // nothing will be scheduled

  const size_t max_arena = mi_atomic_load_acquire(&mi_arena_count);
@ -610,7 +610,7 @@ static void mi_arenas_try_purge( bool force, bool visit_all, mi_stats_t* stats )
    for (size_t i = 0; i < max_arena; i++) {
      mi_arena_t* arena = mi_atomic_load_ptr_acquire(mi_arena_t, &mi_arenas[i]);
      if (arena != NULL) {
-        if (mi_arena_try_purge(arena, now, force, stats)) {
+        if (mi_arena_try_purge(arena, now, force)) {
          if (max_purge_count <= 1) break;
          max_purge_count--;
        }
@ -624,8 +624,8 @@ static void mi_arenas_try_purge( bool force, bool visit_all, mi_stats_t* stats )
  Arena free
 ----------------------------------------------------------- */

-void _mi_arena_free(void* p, size_t size, size_t committed_size, mi_memid_t memid, mi_stats_t* stats) {
-  mi_assert_internal(size > 0 && stats != NULL);
+void _mi_arena_free(void* p, size_t size, size_t committed_size, mi_memid_t memid) {
+  mi_assert_internal(size > 0);
  mi_assert_internal(committed_size <= size);
  if (p==NULL) return;
  if (size==0) return;
@ -640,7 +640,7 @@ void _mi_arena_free(void* p, size_t size, size_t committed_size, mi_memid_t memi
      // if partially committed, adjust the committed stats (as `_mi_os_free` will increase decommit by the full size)
      _mi_stat_decrease(&_mi_stats_main.committed, committed_size);
    }
-    _mi_os_free(p, size, memid, stats);
+    _mi_os_free(p, size, memid);
  }
  else if (memid.memkind == MI_MEM_ARENA) {
    // allocated in an arena
@ -685,7 +685,7 @@ void _mi_arena_free(void* p, size_t size, size_t committed_size, mi_memid_t memi
        // works (as we should never reset decommitted parts).
      }
      // (delay) purge the entire range
-      mi_arena_schedule_purge(arena, bitmap_idx, blocks, stats);
+      mi_arena_schedule_purge(arena, bitmap_idx, blocks);
    }

    // and make it available to others again
@ -701,7 +701,7 @@ void _mi_arena_free(void* p, size_t size, size_t committed_size, mi_memid_t memi
  }

  // purge expired decommits
-  mi_arenas_try_purge(false, false, stats);
+  mi_arenas_try_purge(false, false);
 }

 // destroy owned arenas; this is unsafe and should only be done using `mi_option_destroy_on_exit`
@ -715,7 +715,7 @@ static void mi_arenas_unsafe_destroy(void) {
      mi_lock_done(&arena->abandoned_visit_lock);
      if (arena->start != NULL && mi_memkind_is_os(arena->memid.memkind)) {
        mi_atomic_store_ptr_release(mi_arena_t, &mi_arenas[i], NULL);
-        _mi_os_free(arena->start, mi_arena_size(arena), arena->memid, &_mi_stats_main);
+        _mi_os_free(arena->start, mi_arena_size(arena), arena->memid);
      }
      else {
        new_max_arena = i;
@ -730,15 +730,15 @@ static void mi_arenas_unsafe_destroy(void) {
 }

 // Purge the arenas; if `force_purge` is true, amenable parts are purged even if not yet expired
-void _mi_arenas_collect(bool force_purge, mi_stats_t* stats) {
-  mi_arenas_try_purge(force_purge, force_purge /* visit all? */, stats);
+void _mi_arenas_collect(bool force_purge) {
+  mi_arenas_try_purge(force_purge, force_purge /* visit all? */);
 }

 // destroy owned arenas; this is unsafe and should only be done using `mi_option_destroy_on_exit`
 // for dynamic libraries that are unloaded and need to release all their allocated memory.
-void _mi_arena_unsafe_destroy_all(mi_stats_t* stats) {
+void _mi_arena_unsafe_destroy_all(void) {
  mi_arenas_unsafe_destroy();
-  _mi_arenas_collect(true /* force purge */, stats);  // purge non-owned arenas
+  _mi_arenas_collect(true /* force purge */);  // purge non-owned arenas
 }

 // Is a pointer inside any of our arenas?
@ -842,11 +842,11 @@ int mi_reserve_os_memory_ex(size_t size, bool commit, bool allow_large, bool exc
  if (arena_id != NULL) *arena_id = _mi_arena_id_none();
  size = _mi_align_up(size, MI_ARENA_BLOCK_SIZE); // at least one block
  mi_memid_t memid;
-  void* start = _mi_os_alloc_aligned(size, MI_SEGMENT_ALIGN, commit, allow_large, &memid, &_mi_stats_main);
+  void* start = _mi_os_alloc_aligned(size, MI_SEGMENT_ALIGN, commit, allow_large, &memid);
  if (start == NULL) return ENOMEM;
  const bool is_large = memid.is_pinned; // todo: use separate is_large field?
  if (!mi_manage_os_memory_ex2(start, size, is_large, -1 /* numa node */, exclusive, memid, arena_id)) {
-    _mi_os_free_ex(start, size, commit, memid, &_mi_stats_main);
+    _mi_os_free_ex(start, size, commit, memid);
    _mi_verbose_message("failed to reserve %zu KiB memory\n", _mi_divide_up(size, 1024));
    return ENOMEM;
  }
@ -942,7 +942,7 @@ int mi_reserve_huge_os_pages_at_ex(size_t pages, int numa_node, size_t timeout_m
  _mi_verbose_message("numa node %i: reserved %zu GiB huge pages (of the %zu GiB requested)\n", numa_node, pages_reserved, pages);

  if (!mi_manage_os_memory_ex2(p, hsize, true, numa_node, exclusive, memid, arena_id)) {
-    _mi_os_free(p, hsize, memid, &_mi_stats_main);
+    _mi_os_free(p, hsize, memid);
    return ENOMEM;
  }
  return 0;
--- a/src/bitmap.c
+++ b/src/bitmap.c
@ -200,7 +200,7 @@ bool _mi_bitmap_is_any_claimed(mi_bitmap_t bitmap, size_t bitmap_fields, size_t
 // Try to atomically claim a sequence of `count` bits starting from the field
 // at `idx` in `bitmap` and crossing into subsequent fields. Returns `true` on success.
 // Only needs to consider crossing into the next fields (see `mi_bitmap_try_find_from_claim_across`)
-static bool mi_bitmap_try_find_claim_field_across(mi_bitmap_t bitmap, size_t bitmap_fields, size_t idx, const size_t count, const size_t retries, mi_bitmap_index_t* bitmap_idx, mi_stats_t* stats)
+static bool mi_bitmap_try_find_claim_field_across(mi_bitmap_t bitmap, size_t bitmap_fields, size_t idx, const size_t count, const size_t retries, mi_bitmap_index_t* bitmap_idx)
 {
  mi_assert_internal(bitmap_idx != NULL);

@ -260,7 +260,7 @@ static bool mi_bitmap_try_find_claim_field_across(mi_bitmap_t bitmap, size_t bit
  } while (!mi_atomic_cas_strong_acq_rel(field, &map, newmap));

  // claimed!
-  mi_stat_counter_increase(stats->arena_crossover_count,1);
+  mi_stat_counter_increase(_mi_stats_main.arena_crossover_count,1);
  *bitmap_idx = mi_bitmap_index_create(idx, initial_idx);
  return true;

@ -280,10 +280,10 @@ rollback:
      newmap = (map & ~initial_mask);
    } while (!mi_atomic_cas_strong_acq_rel(field, &map, newmap));
  }
-  mi_stat_counter_increase(stats->arena_rollback_count,1);
+  mi_stat_counter_increase(_mi_stats_main.arena_rollback_count,1);
  // retry? (we make a recursive call instead of goto to be able to use const declarations)
  if (retries <= 2) {
-    return mi_bitmap_try_find_claim_field_across(bitmap, bitmap_fields, idx, count, retries+1, bitmap_idx, stats);
+    return mi_bitmap_try_find_claim_field_across(bitmap, bitmap_fields, idx, count, retries+1, bitmap_idx);
  }
  else {
    return false;
@ -293,7 +293,7 @@ rollback:

 // Find `count` bits of zeros and set them to 1 atomically; returns `true` on success.
 // Starts at idx, and wraps around to search in all `bitmap_fields` fields.
-bool _mi_bitmap_try_find_from_claim_across(mi_bitmap_t bitmap, const size_t bitmap_fields, const size_t start_field_idx, const size_t count, mi_bitmap_index_t* bitmap_idx, mi_stats_t* stats) {
+bool _mi_bitmap_try_find_from_claim_across(mi_bitmap_t bitmap, const size_t bitmap_fields, const size_t start_field_idx, const size_t count, mi_bitmap_index_t* bitmap_idx) {
  mi_assert_internal(count > 0);
  if (count <= 2) {
    // we don't bother with crossover fields for small counts
@ -313,7 +313,7 @@ bool _mi_bitmap_try_find_from_claim_across(mi_bitmap_t bitmap, const size_t bitm
    }
    */
    // if that fails, then try to claim across fields
-    if (mi_bitmap_try_find_claim_field_across(bitmap, bitmap_fields, idx, count, 0, bitmap_idx, stats)) {
+    if (mi_bitmap_try_find_claim_field_across(bitmap, bitmap_fields, idx, count, 0, bitmap_idx)) {
      return true;
    }
  }
--- a/src/bitmap.h
+++ b/src/bitmap.h
@ -103,7 +103,7 @@ bool _mi_bitmap_is_any_claimed(mi_bitmap_t bitmap, size_t bitmap_fields, size_t

 // Find `count` bits of zeros and set them to 1 atomically; returns `true` on success.
 // Starts at idx, and wraps around to search in all `bitmap_fields` fields.
-bool _mi_bitmap_try_find_from_claim_across(mi_bitmap_t bitmap, const size_t bitmap_fields, const size_t start_field_idx, const size_t count, mi_bitmap_index_t* bitmap_idx, mi_stats_t* stats);
+bool _mi_bitmap_try_find_from_claim_across(mi_bitmap_t bitmap, const size_t bitmap_fields, const size_t start_field_idx, const size_t count, mi_bitmap_index_t* bitmap_idx);

 // Set `count` bits at `bitmap_idx` to 0 atomically
 // Returns `true` if all `count` bits were 1 previously.
--- a/src/heap.c
+++ b/src/heap.c
@ -98,7 +98,7 @@ static bool mi_heap_page_collect(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_t
  if (collect == MI_FORCE) {
    // note: call before a potential `_mi_page_free` as the segment may be freed if this was the last used page in that segment.
    mi_segment_t* segment = _mi_page_segment(page);
-    _mi_segment_collect(segment, true /* force? */, &heap->tld->segments);
+    _mi_segment_collect(segment, true /* force? */);
  }
  if (mi_page_all_free(page)) {
    // no more used blocks, free the page.
@ -173,7 +173,7 @@ static void mi_heap_collect_ex(mi_heap_t* heap, mi_collect_t collect)
  }

  // collect arenas (this is program wide so don't force purges on abandonment of threads)
-  _mi_arenas_collect(collect == MI_FORCE /* force purge? */, &heap->tld->stats);
+  _mi_arenas_collect(collect == MI_FORCE /* force purge? */);
 }

 void _mi_heap_collect_abandon(mi_heap_t* heap) {
@ -458,6 +458,12 @@ static void mi_heap_absorb(mi_heap_t* heap, mi_heap_t* from) {
  mi_heap_reset_pages(from);
 }

+// are two heaps compatible with respect to heap-tag, exclusive arena etc.
+static bool mi_heaps_are_compatible(mi_heap_t* heap1, mi_heap_t* heap2) {
+  return (heap1->tag == heap2->tag &&                   // store same kind of objects
+          heap1->arena_id == heap2->arena_id);          // same arena preference
+}
+
 // Safe delete a heap without freeing any still allocated blocks in that heap.
 void mi_heap_delete(mi_heap_t* heap)
 {
@ -466,9 +472,10 @@ void mi_heap_delete(mi_heap_t* heap)
  mi_assert_expensive(mi_heap_is_valid(heap));
  if (heap==NULL || !mi_heap_is_initialized(heap)) return;

-  if (!mi_heap_is_backing(heap)) {
+  mi_heap_t* bheap = heap->tld->heap_backing;
+  if (bheap != heap && mi_heaps_are_compatible(bheap,heap)) {
    // transfer still used pages to the backing heap
-    mi_heap_absorb(heap->tld->heap_backing, heap);
+    mi_heap_absorb(bheap, heap);
  }
  else {
    // the backing heap abandons its pages
--- a/src/init.c
+++ b/src/init.c
@ -135,14 +135,12 @@ mi_decl_cache_align const mi_heap_t _mi_heap_empty = {
 static mi_decl_cache_align mi_subproc_t mi_subproc_default;

 #define tld_empty_stats  ((mi_stats_t*)((uint8_t*)&tld_empty + offsetof(mi_tld_t,stats)))
-#define tld_empty_os     ((mi_os_tld_t*)((uint8_t*)&tld_empty + offsetof(mi_tld_t,os)))

 mi_decl_cache_align static const mi_tld_t tld_empty = {
  0,
  false,
  NULL, NULL,
-  { MI_SEGMENT_SPAN_QUEUES_EMPTY, 0, 0, 0, 0, 0, &mi_subproc_default, tld_empty_stats, tld_empty_os }, // segments
-  { 0, tld_empty_stats }, // os
+  { MI_SEGMENT_SPAN_QUEUES_EMPTY, 0, 0, 0, 0, 0, &mi_subproc_default, tld_empty_stats }, // segments
  { MI_STATS_NULL }       // stats
 };

@ -158,8 +156,7 @@ extern mi_heap_t _mi_heap_main;
 static mi_decl_cache_align mi_tld_t tld_main = {
  0, false,
  &_mi_heap_main, & _mi_heap_main,
-  { MI_SEGMENT_SPAN_QUEUES_EMPTY, 0, 0, 0, 0, 0, &mi_subproc_default, &tld_main.stats, &tld_main.os }, // segments
-  { 0, &tld_main.stats },  // os
+  { MI_SEGMENT_SPAN_QUEUES_EMPTY, 0, 0, 0, 0, 0, &mi_subproc_default, &tld_main.stats }, // segments
  { MI_STATS_NULL }       // stats
 };

@ -341,10 +338,10 @@ static mi_thread_data_t* mi_thread_data_zalloc(void) {
  // if that fails, allocate as meta data
  if (td == NULL) {
    mi_memid_t memid;
-    td = (mi_thread_data_t*)_mi_os_alloc(sizeof(mi_thread_data_t), &memid, &_mi_stats_main);
+    td = (mi_thread_data_t*)_mi_os_alloc(sizeof(mi_thread_data_t), &memid);
    if (td == NULL) {
      // if this fails, try once more. (issue #257)
-      td = (mi_thread_data_t*)_mi_os_alloc(sizeof(mi_thread_data_t), &memid, &_mi_stats_main);
+      td = (mi_thread_data_t*)_mi_os_alloc(sizeof(mi_thread_data_t), &memid);
      if (td == NULL) {
        // really out of memory
        _mi_error_message(ENOMEM, "unable to allocate thread local heap metadata (%zu bytes)\n", sizeof(mi_thread_data_t));
@ -374,7 +371,7 @@ static void mi_thread_data_free( mi_thread_data_t* tdfree ) {
    }
  }
  // if that fails, just free it directly
-  _mi_os_free(tdfree, sizeof(mi_thread_data_t), tdfree->memid, &_mi_stats_main);
+  _mi_os_free(tdfree, sizeof(mi_thread_data_t), tdfree->memid);
 }

 void _mi_thread_data_collect(void) {
@ -384,7 +381,7 @@ void _mi_thread_data_collect(void) {
    if (td != NULL) {
      td = mi_atomic_exchange_ptr_acq_rel(mi_thread_data_t, &td_cache[i], NULL);
      if (td != NULL) {
-        _mi_os_free(td, sizeof(mi_thread_data_t), td->memid, &_mi_stats_main);
+        _mi_os_free(td, sizeof(mi_thread_data_t), td->memid);
      }
    }
  }
@ -420,9 +417,7 @@ void _mi_tld_init(mi_tld_t* tld, mi_heap_t* bheap) {
  tld->heap_backing = bheap;
  tld->heaps = NULL;
  tld->segments.subproc = &mi_subproc_default;
-  tld->segments.stats = &tld->stats;
-  tld->segments.os = &tld->os;
-  tld->os.stats = &tld->stats;
+  tld->segments.stats = &tld->stats;  
 }

 // Free the thread local default heap (called from `mi_thread_done`)
@ -709,7 +704,7 @@ void mi_cdecl _mi_process_done(void) {
  if (mi_option_is_enabled(mi_option_destroy_on_exit)) {
    mi_collect(true /* force */);
    _mi_heap_unsafe_destroy_all();     // forcefully release all memory held by all heaps (of this thread only!)
-    _mi_arena_unsafe_destroy_all(& _mi_heap_main_get()->tld->stats);
+    _mi_arena_unsafe_destroy_all();
  }

  if (mi_option_is_enabled(mi_option_show_stats) || mi_option_is_enabled(mi_option_verbose)) {
--- a/src/os.c
+++ b/src/os.c
@ -9,6 +9,7 @@ terms of the MIT license. A copy of the license can be found in the file
 #include "mimalloc/atomic.h"
 #include "mimalloc/prim.h"

+#define os_stats    (&_mi_stats_main)

 /* -----------------------------------------------------------
  Initialization.
@ -85,8 +86,8 @@ void _mi_os_init(void) {
 /* -----------------------------------------------------------
  Util
 -------------------------------------------------------------- */
-bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats);
-bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats);
+bool _mi_os_decommit(void* addr, size_t size);
+bool _mi_os_commit(void* addr, size_t size, bool* is_zero);


 /* -----------------------------------------------------------
@ -146,23 +147,20 @@ void* _mi_os_get_aligned_hint(size_t try_alignment, size_t size) {
  Free memory
 -------------------------------------------------------------- */

-static void mi_os_free_huge_os_pages(void* p, size_t size, mi_stats_t* stats);
+static void mi_os_free_huge_os_pages(void* p, size_t size);

-static void mi_os_prim_free(void* addr, size_t size, bool still_committed, mi_stats_t* tld_stats) {
-  MI_UNUSED(tld_stats);
-  mi_stats_t* stats = &_mi_stats_main;
+static void mi_os_prim_free(void* addr, size_t size, bool still_committed) {
  mi_assert_internal((size % _mi_os_page_size()) == 0);
  if (addr == NULL || size == 0) return; // || _mi_os_is_huge_reserved(addr)
  int err = _mi_prim_free(addr, size);
  if (err != 0) {
    _mi_warning_message("unable to free OS memory (error: %d (0x%x), size: 0x%zx bytes, address: %p)\n", err, err, size, addr);
  }
-  if (still_committed) { _mi_stat_decrease(&stats->committed, size); }
-  _mi_stat_decrease(&stats->reserved, size);
+  if (still_committed) { _mi_stat_decrease(&os_stats->committed, size); }
+  _mi_stat_decrease(&os_stats->reserved, size);
 }

-void _mi_os_free_ex(void* addr, size_t size, bool still_committed, mi_memid_t memid, mi_stats_t* stats) {
-  if (stats == NULL) stats = &_mi_stats_main;
+void _mi_os_free_ex(void* addr, size_t size, bool still_committed, mi_memid_t memid) {
  if (mi_memkind_is_os(memid.memkind)) {
    size_t csize = _mi_os_good_alloc_size(size);
    void* base = addr;
@ -176,10 +174,10 @@ void _mi_os_free_ex(void* addr, size_t size, bool still_committed, mi_memid_t me
    // free it
    if (memid.memkind == MI_MEM_OS_HUGE) {
      mi_assert(memid.is_pinned);
-      mi_os_free_huge_os_pages(base, csize, stats);
+      mi_os_free_huge_os_pages(base, csize);
    }
    else {
-      mi_os_prim_free(base, csize, still_committed, stats);
+      mi_os_prim_free(base, csize, still_committed);
    }
  }
  else {
@ -188,9 +186,8 @@ void _mi_os_free_ex(void* addr, size_t size, bool still_committed, mi_memid_t me
  }
 }

-void  _mi_os_free(void* p, size_t size, mi_memid_t memid, mi_stats_t* stats) {
-  if (stats == NULL) stats = &_mi_stats_main;
-  _mi_os_free_ex(p, size, true, memid, stats);
+void  _mi_os_free(void* p, size_t size, mi_memid_t memid) {
+  _mi_os_free_ex(p, size, true, memid);
 }


@ -200,7 +197,7 @@ void  _mi_os_free(void* p, size_t size, mi_memid_t memid, mi_stats_t* stats) {

 // Note: the `try_alignment` is just a hint and the returned pointer is not guaranteed to be aligned.
 // Also `hint_addr` is a hint and may be ignored.
-static void* mi_os_prim_alloc_at(void* hint_addr, size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, mi_stats_t* tld_stats) {
+static void* mi_os_prim_alloc_at(void* hint_addr, size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero) {
  mi_assert_internal(size > 0 && (size % _mi_os_page_size()) == 0);
  mi_assert_internal(is_zero != NULL);
  mi_assert_internal(is_large != NULL);
@ -214,13 +211,13 @@ static void* mi_os_prim_alloc_at(void* hint_addr, size_t size, size_t try_alignm
    _mi_warning_message("unable to allocate OS memory (error: %d (0x%x), addr: %p, size: 0x%zx bytes, align: 0x%zx, commit: %d, allow large: %d)\n", err, err, hint_addr, size, try_alignment, commit, allow_large);
  }

-  MI_UNUSED(tld_stats);
-  mi_stats_t* stats = &_mi_stats_main;
-  mi_stat_counter_increase(stats->mmap_calls, 1);
+
+
+  mi_stat_counter_increase(os_stats->mmap_calls, 1);
  if (p != NULL) {
-    _mi_stat_increase(&stats->reserved, size);
+    _mi_stat_increase(&os_stats->reserved, size);
    if (commit) {
-      _mi_stat_increase(&stats->committed, size);
+      _mi_stat_increase(&os_stats->committed, size);
      // seems needed for asan (or `mimalloc-test-api` fails)
      #ifdef MI_TRACK_ASAN
      if (*is_zero) { mi_track_mem_defined(p,size); }
@ -231,14 +228,14 @@ static void* mi_os_prim_alloc_at(void* hint_addr, size_t size, size_t try_alignm
  return p;
 }

-static void* mi_os_prim_alloc(size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, mi_stats_t* tld_stats) {
-  return mi_os_prim_alloc_at(NULL, size, try_alignment, commit, allow_large, is_large, is_zero, tld_stats);
+static void* mi_os_prim_alloc(size_t size, size_t try_alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero) {
+  return mi_os_prim_alloc_at(NULL, size, try_alignment, commit, allow_large, is_large, is_zero);
 }


 // Primitive aligned allocation from the OS.
 // This function guarantees the allocated memory is aligned.
-static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, void** base, mi_stats_t* stats) {
+static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, bool* is_large, bool* is_zero, void** base) {
  mi_assert_internal(alignment >= _mi_os_page_size() && ((alignment & (alignment - 1)) == 0));
  mi_assert_internal(size > 0 && (size % _mi_os_page_size()) == 0);
  mi_assert_internal(is_large != NULL);
@ -249,7 +246,7 @@ static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit
  size = _mi_align_up(size, _mi_os_page_size());

  // try first with a requested alignment hint (this will usually be aligned directly on Win 10+ or BSD)
-  void* p = mi_os_prim_alloc(size, alignment, commit, allow_large, is_large, is_zero, stats);
+  void* p = mi_os_prim_alloc(size, alignment, commit, allow_large, is_large, is_zero);
  if (p == NULL) return NULL;

  // aligned already?
@ -261,13 +258,13 @@ static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit
    #if !MI_TRACK_ASAN
    _mi_warning_message("unable to allocate aligned OS memory directly, fall back to over-allocation (size: 0x%zx bytes, address: %p, alignment: 0x%zx, commit: %d)\n", size, p, alignment, commit);
    #endif
-    mi_os_prim_free(p, size, commit, stats);
+    mi_os_prim_free(p, size, commit);
    if (size >= (SIZE_MAX - alignment)) return NULL; // overflow
    const size_t over_size = size + alignment;

    if (!mi_os_mem_config.has_partial_free) {  // win32 virtualAlloc cannot free parts of an allocated block
      // over-allocate uncommitted (virtual) memory
-      p = mi_os_prim_alloc(over_size, 1 /*alignment*/, false /* commit? */, false /* allow_large */, is_large, is_zero, stats);
+      p = mi_os_prim_alloc(over_size, 1 /*alignment*/, false /* commit? */, false /* allow_large */, is_large, is_zero);
      if (p == NULL) return NULL;

      // set p to the aligned part in the full region
@ -278,12 +275,12 @@ static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit

      // explicitly commit only the aligned part
      if (commit) {
-        _mi_os_commit(p, size, NULL, stats);
+        _mi_os_commit(p, size, NULL);
      }
    }
    else  { // mmap can free inside an allocation
      // overallocate...
-      p = mi_os_prim_alloc(over_size, 1, commit, false, is_large, is_zero, stats);
+      p = mi_os_prim_alloc(over_size, 1, commit, false, is_large, is_zero);
      if (p == NULL) return NULL;

      // and selectively unmap parts around the over-allocated area.
@ -292,8 +289,8 @@ static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit
      size_t mid_size = _mi_align_up(size, _mi_os_page_size());
      size_t post_size = over_size - pre_size - mid_size;
      mi_assert_internal(pre_size < over_size&& post_size < over_size&& mid_size >= size);
-      if (pre_size > 0)  { mi_os_prim_free(p, pre_size, commit, stats); }
-      if (post_size > 0) { mi_os_prim_free((uint8_t*)aligned_p + mid_size, post_size, commit, stats); }
+      if (pre_size > 0)  { mi_os_prim_free(p, pre_size, commit); }
+      if (post_size > 0) { mi_os_prim_free((uint8_t*)aligned_p + mid_size, post_size, commit); }
      // we can return the aligned pointer on `mmap` systems
      p = aligned_p;
      *base = aligned_p; // since we freed the pre part, `*base == p`.
@ -309,33 +306,31 @@ static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit
  OS API: alloc and alloc_aligned
 ----------------------------------------------------------- */

-void* _mi_os_alloc(size_t size, mi_memid_t* memid, mi_stats_t* stats) {
+void* _mi_os_alloc(size_t size, mi_memid_t* memid) {
  *memid = _mi_memid_none();
  if (size == 0) return NULL;
-  if (stats == NULL) stats = &_mi_stats_main;
  size = _mi_os_good_alloc_size(size);
  bool os_is_large = false;
  bool os_is_zero  = false;
-  void* p = mi_os_prim_alloc(size, 0, true, false, &os_is_large, &os_is_zero, stats);
+  void* p = mi_os_prim_alloc(size, 0, true, false, &os_is_large, &os_is_zero);
  if (p != NULL) {
    *memid = _mi_memid_create_os(true, os_is_zero, os_is_large);
  }
  return p;
 }

-void* _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* stats)
+void* _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid)
 {
  MI_UNUSED(&_mi_os_get_aligned_hint); // suppress unused warnings
  *memid = _mi_memid_none();
  if (size == 0) return NULL;
-  if (stats == NULL) stats = &_mi_stats_main;
  size = _mi_os_good_alloc_size(size);
  alignment = _mi_align_up(alignment, _mi_os_page_size());

  bool os_is_large = false;
  bool os_is_zero  = false;
  void* os_base = NULL;
-  void* p = mi_os_prim_alloc_aligned(size, alignment, commit, allow_large, &os_is_large, &os_is_zero, &os_base, stats );
+  void* p = mi_os_prim_alloc_aligned(size, alignment, commit, allow_large, &os_is_large, &os_is_zero, &os_base );
  if (p != NULL) {
    *memid = _mi_memid_create_os(commit, os_is_zero, os_is_large);
    memid->mem.os.base = os_base;
@ -352,29 +347,28 @@ void* _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allo
  to use the actual start of the memory region.
 ----------------------------------------------------------- */

-void* _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t offset, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* stats) {
+void* _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t offset, bool commit, bool allow_large, mi_memid_t* memid) {
  mi_assert(offset <= MI_SEGMENT_SIZE);
  mi_assert(offset <= size);
  mi_assert((alignment % _mi_os_page_size()) == 0);
  *memid = _mi_memid_none();
-  if (stats == NULL) stats = &_mi_stats_main;
  if (offset > MI_SEGMENT_SIZE) return NULL;
  if (offset == 0) {
    // regular aligned allocation
-    return _mi_os_alloc_aligned(size, alignment, commit, allow_large, memid, stats);
+    return _mi_os_alloc_aligned(size, alignment, commit, allow_large, memid);
  }
  else {
    // overallocate to align at an offset
    const size_t extra = _mi_align_up(offset, alignment) - offset;
    const size_t oversize = size + extra;
-    void* const start = _mi_os_alloc_aligned(oversize, alignment, commit, allow_large, memid, stats);
+    void* const start = _mi_os_alloc_aligned(oversize, alignment, commit, allow_large, memid);
    if (start == NULL) return NULL;

    void* const p = (uint8_t*)start + extra;
    mi_assert(_mi_is_aligned((uint8_t*)p + offset, alignment));
    // decommit the overallocation at the start
    if (commit && extra > _mi_os_page_size()) {
-      _mi_os_decommit(start, extra, stats);
+      _mi_os_decommit(start, extra);
    }
    return p;
  }
@ -408,12 +402,10 @@ static void* mi_os_page_align_area_conservative(void* addr, size_t size, size_t*
  return mi_os_page_align_areax(true, addr, size, newsize);
 }

-bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats) {
-  MI_UNUSED(tld_stats);
-  mi_stats_t* stats = &_mi_stats_main;
+bool _mi_os_commit(void* addr, size_t size, bool* is_zero) {
  if (is_zero != NULL) { *is_zero = false; }
-  _mi_stat_increase(&stats->committed, size);  // use size for precise commit vs. decommit
-  _mi_stat_counter_increase(&stats->commit_calls, 1);
+  _mi_stat_increase(&os_stats->committed, size);  // use size for precise commit vs. decommit
+  _mi_stat_counter_increase(&os_stats->commit_calls, 1);

  // page align range
  size_t csize;
@ -439,11 +431,8 @@ bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats
  return true;
 }

-static bool mi_os_decommit_ex(void* addr, size_t size, bool* needs_recommit, mi_stats_t* tld_stats) {
-  MI_UNUSED(tld_stats);
-  mi_stats_t* stats = &_mi_stats_main;
-  mi_assert_internal(needs_recommit!=NULL);
-  _mi_stat_decrease(&stats->committed, size);
+static bool mi_os_decommit_ex(void* addr, size_t size, bool* needs_recommit) {  mi_assert_internal(needs_recommit!=NULL);
+  _mi_stat_decrease(&os_stats->committed, size);

  // page align
  size_t csize;
@ -460,9 +449,9 @@ static bool mi_os_decommit_ex(void* addr, size_t size, bool* needs_recommit, mi_
  return (err == 0);
 }

-bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* tld_stats) {
+bool _mi_os_decommit(void* addr, size_t size) {
  bool needs_recommit;
-  return mi_os_decommit_ex(addr, size, &needs_recommit, tld_stats);
+  return mi_os_decommit_ex(addr, size, &needs_recommit);
 }


@ -470,13 +459,13 @@ bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* tld_stats) {
 // but may be used later again. This will release physical memory
 // pages and reduce swapping while keeping the memory committed.
 // We page align to a conservative area inside the range to reset.
-bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) {
+bool _mi_os_reset(void* addr, size_t size) {
  // page align conservatively within the range
  size_t csize;
  void* start = mi_os_page_align_area_conservative(addr, size, &csize);
  if (csize == 0) return true;  // || _mi_os_is_huge_reserved(addr)
-  _mi_stat_increase(&stats->reset, csize);
-  _mi_stat_counter_increase(&stats->reset_calls, 1);
+  _mi_stat_increase(&os_stats->reset, csize);
+  _mi_stat_counter_increase(&os_stats->reset_calls, 1);

  #if (MI_DEBUG>1) && !MI_SECURE && !MI_TRACK_ENABLED // && !MI_TSAN
  memset(start, 0, csize); // pretend it is eagerly reset
@ -492,22 +481,22 @@ bool _mi_os_reset(void* addr, size_t size, mi_stats_t* stats) {

 // either resets or decommits memory, returns true if the memory needs
 // to be recommitted if it is to be re-used later on.
-bool _mi_os_purge_ex(void* p, size_t size, bool allow_reset, mi_stats_t* stats)
+bool _mi_os_purge_ex(void* p, size_t size, bool allow_reset)
 {
  if (mi_option_get(mi_option_purge_delay) < 0) return false;  // is purging allowed?
-  _mi_stat_counter_increase(&stats->purge_calls, 1);
-  _mi_stat_increase(&stats->purged, size);
+  _mi_stat_counter_increase(&os_stats->purge_calls, 1);
+  _mi_stat_increase(&os_stats->purged, size);

  if (mi_option_is_enabled(mi_option_purge_decommits) &&   // should decommit?
      !_mi_preloading())                                   // don't decommit during preloading (unsafe)
  {
    bool needs_recommit = true;
-    mi_os_decommit_ex(p, size, &needs_recommit, stats);
+    mi_os_decommit_ex(p, size, &needs_recommit);
    return needs_recommit;
  }
  else {
    if (allow_reset) {  // this can sometimes be not allowed if the range is not fully committed
-      _mi_os_reset(p, size, stats);
+      _mi_os_reset(p, size);
    }
    return false;  // needs no recommit
  }
@ -515,8 +504,8 @@ bool _mi_os_purge_ex(void* p, size_t size, bool allow_reset, mi_stats_t* stats)

 // either resets or decommits memory, returns true if the memory needs
 // to be recommitted if it is to be re-used later on.
-bool _mi_os_purge(void* p, size_t size, mi_stats_t * stats) {
-  return _mi_os_purge_ex(p, size, true, stats);
+bool _mi_os_purge(void* p, size_t size) {
+  return _mi_os_purge_ex(p, size, true);
 }

 // Protect a region in memory to be not accessible.
@ -623,15 +612,15 @@ void* _mi_os_alloc_huge_os_pages(size_t pages, int numa_node, mi_msecs_t max_mse
      // no success, issue a warning and break
      if (p != NULL) {
        _mi_warning_message("could not allocate contiguous huge OS page %zu at %p\n", page, addr);
-        mi_os_prim_free(p, MI_HUGE_OS_PAGE_SIZE, true, &_mi_stats_main);
+        mi_os_prim_free(p, MI_HUGE_OS_PAGE_SIZE, true);
      }
      break;
    }

    // success, record it
    page++;  // increase before timeout check (see issue #711)
-    _mi_stat_increase(&_mi_stats_main.committed, MI_HUGE_OS_PAGE_SIZE);
-    _mi_stat_increase(&_mi_stats_main.reserved, MI_HUGE_OS_PAGE_SIZE);
+    _mi_stat_increase(&os_stats->committed, MI_HUGE_OS_PAGE_SIZE);
+    _mi_stat_increase(&os_stats->reserved, MI_HUGE_OS_PAGE_SIZE);

    // check for timeout
    if (max_msecs > 0) {
@ -665,11 +654,11 @@ void* _mi_os_alloc_huge_os_pages(size_t pages, int numa_node, mi_msecs_t max_mse

 // free every huge page in a range individually (as we allocated per page)
 // note: needed with VirtualAlloc but could potentially be done in one go on mmap'd systems.
-static void mi_os_free_huge_os_pages(void* p, size_t size, mi_stats_t* stats) {
+static void mi_os_free_huge_os_pages(void* p, size_t size) {
  if (p==NULL || size==0) return;
  uint8_t* base = (uint8_t*)p;
  while (size >= MI_HUGE_OS_PAGE_SIZE) {
-    mi_os_prim_free(base, MI_HUGE_OS_PAGE_SIZE, true, stats);
+    mi_os_prim_free(base, MI_HUGE_OS_PAGE_SIZE, true);
    size -= MI_HUGE_OS_PAGE_SIZE;
    base += MI_HUGE_OS_PAGE_SIZE;
  }
@ -698,8 +687,7 @@ size_t _mi_os_numa_node_count_get(void) {
  return count;
 }

-int _mi_os_numa_node_get(mi_os_tld_t* tld) {
-  MI_UNUSED(tld);
+int _mi_os_numa_node_get(void) {
  size_t numa_count = _mi_os_numa_node_count();
  if (numa_count<=1) return 0; // optimize on single numa node systems: always node 0
  // never more than the node count and >= 0
--- a/src/page.c
+++ b/src/page.c
@ -276,7 +276,7 @@ static mi_page_t* mi_page_fresh_alloc(mi_heap_t* heap, mi_page_queue_t* pq, size
  mi_assert_internal(mi_heap_contains_queue(heap, pq));
  mi_assert_internal(page_alignment > 0 || block_size > MI_MEDIUM_OBJ_SIZE_MAX || block_size == pq->block_size);
  #endif
-  mi_page_t* page = _mi_segment_page_alloc(heap, block_size, page_alignment, &heap->tld->segments, &heap->tld->os);
+  mi_page_t* page = _mi_segment_page_alloc(heap, block_size, page_alignment, &heap->tld->segments);
  if (page == NULL) {
    // this may be out-of-memory, or an abandoned page was reclaimed (and in our queue)
    return NULL;
--- a/src/segment-map.c
+++ b/src/segment-map.c
@ -55,11 +55,11 @@ static mi_segmap_part_t* mi_segment_map_index_of(const mi_segment_t* segment, bo
  if (part == NULL) {
    if (!create_on_demand) return NULL;
    mi_memid_t memid;
-    part = (mi_segmap_part_t*)_mi_os_alloc(sizeof(mi_segmap_part_t), &memid, NULL);
+    part = (mi_segmap_part_t*)_mi_os_alloc(sizeof(mi_segmap_part_t), &memid);
    if (part == NULL) return NULL;
    mi_segmap_part_t* expected = NULL;
    if (!mi_atomic_cas_ptr_strong_release(mi_segmap_part_t, &mi_segment_map[segindex], &expected, part)) {
-      _mi_os_free(part, sizeof(mi_segmap_part_t), memid, NULL);
+      _mi_os_free(part, sizeof(mi_segmap_part_t), memid);
      part = expected;
      if (part == NULL) return NULL;
    }
--- a/src/segment.c
+++ b/src/segment.c
@ -17,7 +17,7 @@ terms of the MIT license. A copy of the license can be found in the file
 // -------------------------------------------------------------------


-static void mi_segment_try_purge(mi_segment_t* segment, bool force, mi_stats_t* stats);
+static void mi_segment_try_purge(mi_segment_t* segment, bool force);


 // -------------------------------------------------------------------
@ -410,7 +410,7 @@ static void mi_segment_os_free(mi_segment_t* segment, mi_segments_tld_t* tld) {
  const size_t size = mi_segment_size(segment);
  const size_t csize = _mi_commit_mask_committed_size(&segment->commit_mask, size);

-  _mi_arena_free(segment, mi_segment_size(segment), csize, segment->memid, tld->stats);
+  _mi_arena_free(segment, mi_segment_size(segment), csize, segment->memid);
 }

 /* -----------------------------------------------------------
@ -467,7 +467,7 @@ static void mi_segment_commit_mask(mi_segment_t* segment, bool conservative, uin
  mi_commit_mask_create(bitidx, bitcount, cm);
 }

-static bool mi_segment_commit(mi_segment_t* segment, uint8_t* p, size_t size, mi_stats_t* stats) {
+static bool mi_segment_commit(mi_segment_t* segment, uint8_t* p, size_t size) {
  mi_assert_internal(mi_commit_mask_all_set(&segment->commit_mask, &segment->purge_mask));

  // commit liberal
@ -483,7 +483,7 @@ static bool mi_segment_commit(mi_segment_t* segment, uint8_t* p, size_t size, mi
    mi_commit_mask_t cmask;
    mi_commit_mask_create_intersect(&segment->commit_mask, &mask, &cmask);
    _mi_stat_decrease(&_mi_stats_main.committed, _mi_commit_mask_committed_size(&cmask, MI_SEGMENT_SIZE)); // adjust for overlap
-    if (!_mi_os_commit(start, full_size, &is_zero, stats)) return false;
+    if (!_mi_os_commit(start, full_size, &is_zero)) return false;
    mi_commit_mask_set(&segment->commit_mask, &mask);
  }

@ -497,15 +497,15 @@ static bool mi_segment_commit(mi_segment_t* segment, uint8_t* p, size_t size, mi
  return true;
 }

-static bool mi_segment_ensure_committed(mi_segment_t* segment, uint8_t* p, size_t size, mi_stats_t* stats) {
+static bool mi_segment_ensure_committed(mi_segment_t* segment, uint8_t* p, size_t size) {
  mi_assert_internal(mi_commit_mask_all_set(&segment->commit_mask, &segment->purge_mask));
  // note: assumes commit_mask is always full for huge segments as otherwise the commit mask bits can overflow
  if (mi_commit_mask_is_full(&segment->commit_mask) && mi_commit_mask_is_empty(&segment->purge_mask)) return true; // fully committed
  mi_assert_internal(segment->kind != MI_SEGMENT_HUGE);
-  return mi_segment_commit(segment, p, size, stats);
+  return mi_segment_commit(segment, p, size);
 }

-static bool mi_segment_purge(mi_segment_t* segment, uint8_t* p, size_t size, mi_stats_t* stats) {
+static bool mi_segment_purge(mi_segment_t* segment, uint8_t* p, size_t size) {
  mi_assert_internal(mi_commit_mask_all_set(&segment->commit_mask, &segment->purge_mask));
  if (!segment->allow_purge) return true;

@ -520,7 +520,7 @@ static bool mi_segment_purge(mi_segment_t* segment, uint8_t* p, size_t size, mi_
    // purging
    mi_assert_internal((void*)start != (void*)segment);
    mi_assert_internal(segment->allow_decommit);
-    const bool decommitted = _mi_os_purge(start, full_size, stats);  // reset or decommit
+    const bool decommitted = _mi_os_purge(start, full_size);  // reset or decommit
    if (decommitted) {
      mi_commit_mask_t cmask;
      mi_commit_mask_create_intersect(&segment->commit_mask, &mask, &cmask);
@ -534,11 +534,11 @@ static bool mi_segment_purge(mi_segment_t* segment, uint8_t* p, size_t size, mi_
  return true;
 }

-static void mi_segment_schedule_purge(mi_segment_t* segment, uint8_t* p, size_t size, mi_stats_t* stats) {
+static void mi_segment_schedule_purge(mi_segment_t* segment, uint8_t* p, size_t size) {
  if (!segment->allow_purge) return;

  if (mi_option_get(mi_option_purge_delay) == 0) {
-    mi_segment_purge(segment, p, size, stats);
+    mi_segment_purge(segment, p, size);
  }
  else {
    // register for future purge in the purge mask
@ -561,7 +561,7 @@ static void mi_segment_schedule_purge(mi_segment_t* segment, uint8_t* p, size_t
    else if (segment->purge_expire <= now) {
      // previous purge mask already expired
      if (segment->purge_expire + mi_option_get(mi_option_purge_extend_delay) <= now) {
-        mi_segment_try_purge(segment, true, stats);
+        mi_segment_try_purge(segment, true);
      }
      else {
        segment->purge_expire = now + mi_option_get(mi_option_purge_extend_delay); // (mi_option_get(mi_option_purge_delay) / 8); // wait a tiny bit longer in case there is a series of free's
@ -574,7 +574,7 @@ static void mi_segment_schedule_purge(mi_segment_t* segment, uint8_t* p, size_t
  }
 }

-static void mi_segment_try_purge(mi_segment_t* segment, bool force, mi_stats_t* stats) {
+static void mi_segment_try_purge(mi_segment_t* segment, bool force) {
  if (!segment->allow_purge || segment->purge_expire == 0 || mi_commit_mask_is_empty(&segment->purge_mask)) return;
  mi_msecs_t now = _mi_clock_now();
  if (!force && now < segment->purge_expire) return;
@ -590,7 +590,7 @@ static void mi_segment_try_purge(mi_segment_t* segment, bool force, mi_stats_t*
    if (count > 0) {
      uint8_t* p = (uint8_t*)segment + (idx*MI_COMMIT_SIZE);
      size_t size = count * MI_COMMIT_SIZE;
-      mi_segment_purge(segment, p, size, stats);
+      mi_segment_purge(segment, p, size);
    }
  }
  mi_commit_mask_foreach_end()
@ -599,8 +599,8 @@ static void mi_segment_try_purge(mi_segment_t* segment, bool force, mi_stats_t*

 // called from `mi_heap_collect_ex`
 // this can be called per-page so it is important that try_purge has fast exit path
-void _mi_segment_collect(mi_segment_t* segment, bool force, mi_segments_tld_t* tld) {
-  mi_segment_try_purge(segment, force, tld->stats);
+void _mi_segment_collect(mi_segment_t* segment, bool force) {
+  mi_segment_try_purge(segment, force);
 }

 /* -----------------------------------------------------------
@ -635,7 +635,7 @@ static void mi_segment_span_free(mi_segment_t* segment, size_t slice_index, size

  // perhaps decommit
  if (allow_purge) {
-    mi_segment_schedule_purge(segment, mi_slice_start(slice), slice_count * MI_SEGMENT_SLICE_SIZE, tld->stats);
+    mi_segment_schedule_purge(segment, mi_slice_start(slice), slice_count * MI_SEGMENT_SLICE_SIZE);
  }

  // and push it on the free page queue (if it was not a huge page)
@ -712,13 +712,13 @@ static mi_slice_t* mi_segment_span_free_coalesce(mi_slice_t* slice, mi_segments_
 ----------------------------------------------------------- */

 // Note: may still return NULL if committing the memory failed
-static mi_page_t* mi_segment_span_allocate(mi_segment_t* segment, size_t slice_index, size_t slice_count, mi_segments_tld_t* tld) {
+static mi_page_t* mi_segment_span_allocate(mi_segment_t* segment, size_t slice_index, size_t slice_count) {
  mi_assert_internal(slice_index < segment->slice_entries);
  mi_slice_t* const slice = &segment->slices[slice_index];
  mi_assert_internal(slice->block_size==0 || slice->block_size==1);

  // commit before changing the slice data
-  if (!mi_segment_ensure_committed(segment, _mi_segment_page_start_from_slice(segment, slice, 0, NULL), slice_count * MI_SEGMENT_SLICE_SIZE, tld->stats)) {
+  if (!mi_segment_ensure_committed(segment, _mi_segment_page_start_from_slice(segment, slice, 0, NULL), slice_count * MI_SEGMENT_SLICE_SIZE)) {
    return NULL;  // commit failed!
  }

@ -791,7 +791,7 @@ static mi_page_t* mi_segments_page_find_and_allocate(size_t slice_count, mi_aren
            mi_segment_slice_split(segment, slice, slice_count, tld);
          }
          mi_assert_internal(slice != NULL && slice->slice_count == slice_count && slice->block_size > 0);
-          mi_page_t* page = mi_segment_span_allocate(segment, mi_slice_index(slice), slice->slice_count, tld);
+          mi_page_t* page = mi_segment_span_allocate(segment, mi_slice_index(slice), slice->slice_count);
          if (page == NULL) {
            // commit failed; return NULL but first restore the slice
            mi_segment_span_free_coalesce(slice, tld);
@ -814,7 +814,7 @@ static mi_page_t* mi_segments_page_find_and_allocate(size_t slice_count, mi_aren

 static mi_segment_t* mi_segment_os_alloc( size_t required, size_t page_alignment, bool eager_delayed, mi_arena_id_t req_arena_id,
                                          size_t* psegment_slices, size_t* pinfo_slices,
-                                          bool commit, mi_segments_tld_t* tld, mi_os_tld_t* os_tld)
+                                          bool commit, mi_segments_tld_t* tld)

 {
  mi_memid_t memid;
@ -835,7 +835,7 @@ static mi_segment_t* mi_segment_os_alloc( size_t required, size_t page_alignment
  }

  const size_t segment_size = (*psegment_slices) * MI_SEGMENT_SLICE_SIZE;
-  mi_segment_t* segment = (mi_segment_t*)_mi_arena_alloc_aligned(segment_size, alignment, align_offset, commit, allow_large, req_arena_id, &memid, os_tld);
+  mi_segment_t* segment = (mi_segment_t*)_mi_arena_alloc_aligned(segment_size, alignment, align_offset, commit, allow_large, req_arena_id, &memid);
  if (segment == NULL) {
    return NULL;  // failed to allocate
  }
@ -851,8 +851,8 @@ static mi_segment_t* mi_segment_os_alloc( size_t required, size_t page_alignment
    mi_assert_internal(commit_needed>0);
    mi_commit_mask_create(0, commit_needed, &commit_mask);
    mi_assert_internal(commit_needed*MI_COMMIT_SIZE >= (*pinfo_slices)*MI_SEGMENT_SLICE_SIZE);
-    if (!_mi_os_commit(segment, commit_needed*MI_COMMIT_SIZE, NULL, tld->stats)) {
-      _mi_arena_free(segment,segment_size,0,memid,tld->stats);
+    if (!_mi_os_commit(segment, commit_needed*MI_COMMIT_SIZE, NULL)) {
+      _mi_arena_free(segment,segment_size,0,memid);
      return NULL;
    }
  }
@ -874,7 +874,7 @@ static mi_segment_t* mi_segment_os_alloc( size_t required, size_t page_alignment


 // Allocate a segment from the OS aligned to `MI_SEGMENT_SIZE` .
-static mi_segment_t* mi_segment_alloc(size_t required, size_t page_alignment, mi_arena_id_t req_arena_id, mi_segments_tld_t* tld, mi_os_tld_t* os_tld, mi_page_t** huge_page)
+static mi_segment_t* mi_segment_alloc(size_t required, size_t page_alignment, mi_arena_id_t req_arena_id, mi_segments_tld_t* tld, mi_page_t** huge_page)
 {
  mi_assert_internal((required==0 && huge_page==NULL) || (required>0 && huge_page != NULL));

@ -892,7 +892,7 @@ static mi_segment_t* mi_segment_alloc(size_t required, size_t page_alignment, mi

  // Allocate the segment from the OS
  mi_segment_t* segment = mi_segment_os_alloc(required, page_alignment, eager_delay, req_arena_id,
-                                              &segment_slices, &info_slices, commit, tld, os_tld);
+                                              &segment_slices, &info_slices, commit, tld);
  if (segment == NULL) return NULL;

  // zero the segment info? -- not always needed as it may be zero initialized from the OS
@ -923,14 +923,14 @@ static mi_segment_t* mi_segment_alloc(size_t required, size_t page_alignment, mi
    size_t os_pagesize = _mi_os_page_size();
    _mi_os_protect((uint8_t*)segment + mi_segment_info_size(segment) - os_pagesize, os_pagesize);
    uint8_t* end = (uint8_t*)segment + mi_segment_size(segment) - os_pagesize;
-    mi_segment_ensure_committed(segment, end, os_pagesize, tld->stats);
+    mi_segment_ensure_committed(segment, end, os_pagesize);
    _mi_os_protect(end, os_pagesize);
    if (slice_entries == segment_slices) segment->slice_entries--; // don't use the last slice :-(
    guard_slices = 1;
  }

  // reserve first slices for segment info
-  mi_page_t* page0 = mi_segment_span_allocate(segment, 0, info_slices, tld);
+  mi_page_t* page0 = mi_segment_span_allocate(segment, 0, info_slices);
  mi_assert_internal(page0!=NULL); if (page0==NULL) return NULL; // cannot fail as we always commit in advance
  mi_assert_internal(segment->used == 1);
  segment->used = 0; // don't count our internal slices towards usage
@ -944,7 +944,7 @@ static mi_segment_t* mi_segment_alloc(size_t required, size_t page_alignment, mi
    mi_assert_internal(huge_page!=NULL);
    mi_assert_internal(mi_commit_mask_is_empty(&segment->purge_mask));
    mi_assert_internal(mi_commit_mask_is_full(&segment->commit_mask));
-    *huge_page = mi_segment_span_allocate(segment, info_slices, segment_slices - info_slices - guard_slices, tld);
+    *huge_page = mi_segment_span_allocate(segment, info_slices, segment_slices - info_slices - guard_slices);
    mi_assert_internal(*huge_page != NULL); // cannot fail as we commit in advance
  }

@ -1011,7 +1011,7 @@ static mi_slice_t* mi_segment_page_clear(mi_page_t* page, mi_segments_tld_t* tld
  if (segment->allow_decommit && mi_option_is_enabled(mi_option_deprecated_page_reset)) {
    size_t psize;
    uint8_t* start = _mi_segment_page_start(segment, page, &psize);
-    _mi_os_reset(start, psize, tld->stats);
+    _mi_os_reset(start, psize);
  }

  // zero the page data, but not the segment fields and heap tag
@ -1050,7 +1050,7 @@ void _mi_segment_page_free(mi_page_t* page, bool force, mi_segments_tld_t* tld)
  }
  else {
    // perform delayed purges
-    mi_segment_try_purge(segment, false /* force? */, tld->stats);
+    mi_segment_try_purge(segment, false /* force? */);
  }
 }

@ -1100,7 +1100,7 @@ static void mi_segment_abandon(mi_segment_t* segment, mi_segments_tld_t* tld) {
  // Only abandoned segments in arena memory can be reclaimed without a free
  // so if a segment is not from an arena we force purge here to be conservative.
  const bool force_purge = (segment->memid.memkind != MI_MEM_ARENA) || mi_option_is_enabled(mi_option_abandoned_page_purge);
-  mi_segment_try_purge(segment, force_purge, tld->stats);
+  mi_segment_try_purge(segment, force_purge);

  // all pages in the segment are abandoned; add it to the abandoned list
  _mi_stat_increase(&tld->stats->segments_abandoned, 1);
@ -1350,7 +1350,7 @@ static mi_segment_t* mi_segment_try_reclaim(mi_heap_t* heap, size_t needed_slice
    }
    else {
      // otherwise, push on the visited list so it gets not looked at too quickly again
-      mi_segment_try_purge(segment, false /* true force? */, tld->stats); // force purge if needed as we may not visit soon again
+      mi_segment_try_purge(segment, false /* true force? */); // force purge if needed as we may not visit soon again
      _mi_arena_segment_mark_abandoned(segment);
    }
  }
@ -1375,7 +1375,7 @@ void _mi_abandoned_collect(mi_heap_t* heap, bool force, mi_segments_tld_t* tld)
    else {
      // otherwise, purge if needed and push on the visited list
      // note: forced purge can be expensive if many threads are destroyed/created as in mstress.
-      mi_segment_try_purge(segment, force, tld->stats);
+      mi_segment_try_purge(segment, force);
      _mi_arena_segment_mark_abandoned(segment);
    }
  }
@ -1434,7 +1434,7 @@ static void mi_segment_force_abandon(mi_segment_t* segment, mi_segments_tld_t* t
  }
  else {
    // perform delayed purges
-    mi_segment_try_purge(segment, false /* force? */, tld->stats);
+    mi_segment_try_purge(segment, false /* force? */);
  }
 }

@ -1483,7 +1483,7 @@ void mi_collect_reduce(size_t target_size) mi_attr_noexcept {
   Reclaim or allocate
 ----------------------------------------------------------- */

-static mi_segment_t* mi_segment_reclaim_or_alloc(mi_heap_t* heap, size_t needed_slices, size_t block_size, mi_segments_tld_t* tld, mi_os_tld_t* os_tld)
+static mi_segment_t* mi_segment_reclaim_or_alloc(mi_heap_t* heap, size_t needed_slices, size_t block_size, mi_segments_tld_t* tld)
 {
  mi_assert_internal(block_size <= MI_LARGE_OBJ_SIZE_MAX);

@ -1503,7 +1503,7 @@ static mi_segment_t* mi_segment_reclaim_or_alloc(mi_heap_t* heap, size_t needed_
    return segment;
  }
  // 2. otherwise allocate a fresh segment
-  return mi_segment_alloc(0, 0, heap->arena_id, tld, os_tld, NULL);
+  return mi_segment_alloc(0, 0, heap->arena_id, tld, NULL);
 }


@ -1511,7 +1511,7 @@ static mi_segment_t* mi_segment_reclaim_or_alloc(mi_heap_t* heap, size_t needed_
   Page allocation
 ----------------------------------------------------------- */

-static mi_page_t* mi_segments_page_alloc(mi_heap_t* heap, mi_page_kind_t page_kind, size_t required, size_t block_size, mi_segments_tld_t* tld, mi_os_tld_t* os_tld)
+static mi_page_t* mi_segments_page_alloc(mi_heap_t* heap, mi_page_kind_t page_kind, size_t required, size_t block_size, mi_segments_tld_t* tld)
 {
  mi_assert_internal(required <= MI_LARGE_OBJ_SIZE_MAX && page_kind <= MI_PAGE_LARGE);

@ -1522,18 +1522,18 @@ static mi_page_t* mi_segments_page_alloc(mi_heap_t* heap, mi_page_kind_t page_ki
  mi_page_t* page = mi_segments_page_find_and_allocate(slices_needed, heap->arena_id, tld); //(required <= MI_SMALL_SIZE_MAX ? 0 : slices_needed), tld);
  if (page==NULL) {
    // no free page, allocate a new segment and try again
-    if (mi_segment_reclaim_or_alloc(heap, slices_needed, block_size, tld, os_tld) == NULL) {
+    if (mi_segment_reclaim_or_alloc(heap, slices_needed, block_size, tld) == NULL) {
      // OOM or reclaimed a good page in the heap
      return NULL;
    }
    else {
      // otherwise try again
-      return mi_segments_page_alloc(heap, page_kind, required, block_size, tld, os_tld);
+      return mi_segments_page_alloc(heap, page_kind, required, block_size, tld);
    }
  }
  mi_assert_internal(page != NULL && page->slice_count*MI_SEGMENT_SLICE_SIZE == page_size);
  mi_assert_internal(_mi_ptr_segment(page)->thread_id == _mi_thread_id());
-  mi_segment_try_purge(_mi_ptr_segment(page), false, tld->stats);
+  mi_segment_try_purge(_mi_ptr_segment(page), false);
  return page;
 }

@ -1543,10 +1543,10 @@ static mi_page_t* mi_segments_page_alloc(mi_heap_t* heap, mi_page_kind_t page_ki
   Huge page allocation
 ----------------------------------------------------------- */

-static mi_page_t* mi_segment_huge_page_alloc(size_t size, size_t page_alignment, mi_arena_id_t req_arena_id, mi_segments_tld_t* tld, mi_os_tld_t* os_tld)
+static mi_page_t* mi_segment_huge_page_alloc(size_t size, size_t page_alignment, mi_arena_id_t req_arena_id, mi_segments_tld_t* tld)
 {
  mi_page_t* page = NULL;
-  mi_segment_t* segment = mi_segment_alloc(size,page_alignment,req_arena_id,tld,os_tld,&page);
+  mi_segment_t* segment = mi_segment_alloc(size,page_alignment,req_arena_id,tld,&page);
  if (segment == NULL || page==NULL) return NULL;
  mi_assert_internal(segment->used==1);
  mi_assert_internal(mi_page_block_size(page) >= size);
@ -1568,7 +1568,7 @@ static mi_page_t* mi_segment_huge_page_alloc(size_t size, size_t page_alignment,
    mi_assert_internal(psize - (aligned_p - start) >= size);
    uint8_t* decommit_start = start + sizeof(mi_block_t);              // for the free list
    ptrdiff_t decommit_size = aligned_p - decommit_start;
-    _mi_os_reset(decommit_start, decommit_size, &_mi_stats_main);   // note: cannot use segment_decommit on huge segments
+    _mi_os_reset(decommit_start, decommit_size);   // note: cannot use segment_decommit on huge segments
  }

  return page;
@ -1615,7 +1615,7 @@ void _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, mi_bloc
    if (csize > sizeof(mi_block_t)) {
      csize = csize - sizeof(mi_block_t);
      uint8_t* p = (uint8_t*)block + sizeof(mi_block_t);
-      _mi_os_reset(p, csize, &_mi_stats_main);  // note: cannot use segment_decommit on huge segments
+      _mi_os_reset(p, csize);  // note: cannot use segment_decommit on huge segments
    }
  }
 }
@ -1624,25 +1624,25 @@ void _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, mi_bloc
 /* -----------------------------------------------------------
   Page allocation and free
 ----------------------------------------------------------- */
-mi_page_t* _mi_segment_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment, mi_segments_tld_t* tld, mi_os_tld_t* os_tld) {
+mi_page_t* _mi_segment_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment, mi_segments_tld_t* tld) {
  mi_page_t* page;
  if mi_unlikely(page_alignment > MI_BLOCK_ALIGNMENT_MAX) {
    mi_assert_internal(_mi_is_power_of_two(page_alignment));
    mi_assert_internal(page_alignment >= MI_SEGMENT_SIZE);
    if (page_alignment < MI_SEGMENT_SIZE) { page_alignment = MI_SEGMENT_SIZE; }
-    page = mi_segment_huge_page_alloc(block_size,page_alignment,heap->arena_id,tld,os_tld);
+    page = mi_segment_huge_page_alloc(block_size,page_alignment,heap->arena_id,tld);
  }
  else if (block_size <= MI_SMALL_OBJ_SIZE_MAX) {
-    page = mi_segments_page_alloc(heap,MI_PAGE_SMALL,block_size,block_size,tld,os_tld);
+    page = mi_segments_page_alloc(heap,MI_PAGE_SMALL,block_size,block_size,tld);
  }
  else if (block_size <= MI_MEDIUM_OBJ_SIZE_MAX) {
-    page = mi_segments_page_alloc(heap,MI_PAGE_MEDIUM,MI_MEDIUM_PAGE_SIZE,block_size,tld, os_tld);
+    page = mi_segments_page_alloc(heap,MI_PAGE_MEDIUM,MI_MEDIUM_PAGE_SIZE,block_size,tld);
  }
  else if (block_size <= MI_LARGE_OBJ_SIZE_MAX) {
-    page = mi_segments_page_alloc(heap,MI_PAGE_LARGE,block_size,block_size,tld, os_tld);
+    page = mi_segments_page_alloc(heap,MI_PAGE_LARGE,block_size,block_size,tld);
  }
  else {
-    page = mi_segment_huge_page_alloc(block_size,page_alignment,heap->arena_id,tld,os_tld);
+    page = mi_segment_huge_page_alloc(block_size,page_alignment,heap->arena_id,tld);
  }
  mi_assert_internal(page == NULL || _mi_heap_memid_is_suitable(heap, _mi_page_segment(page)->memid));
  mi_assert_expensive(page == NULL || mi_segment_is_valid(_mi_page_segment(page),tld));
--- a/test/main-override-static.c
+++ b/test/main-override-static.c
@ -316,11 +316,11 @@ static void test_large_pages(void) {
 static inline uint8_t mi_bsr32(uint32_t x);

 #if defined(_MSC_VER)
-#include <windows.h>
+//#include <Windows.h>
 #include <intrin.h>
 static inline uint8_t mi_bsr32(uint32_t x) {
  uint32_t idx;
-  _BitScanReverse((DWORD*)&idx, x);
+  _BitScanReverse(&idx, x);
  return idx;
 }
 #elif defined(__GNUC__) || defined(__clang__)
@ -344,7 +344,7 @@ static inline uint8_t mi_bsr32(uint32_t x) {
 }
 #endif

-/*
+
 // Bit scan reverse: return the index of the highest bit.
 uint8_t _mi_bsr(uintptr_t x) {
  if (x == 0) return 0;
@ -357,7 +357,7 @@ uint8_t _mi_bsr(uintptr_t x) {
  # error "define bsr for non-32 or 64-bit platforms"
  #endif
 }
-*/
+


 static inline size_t _mi_wsize_from_size(size_t size) {
@ -434,11 +434,20 @@ static inline uint8_t _mi_bin4(size_t size) {
  return bin;
 }

-static size_t _mi_binx4(size_t bsize) {
-  if (bsize==0) return 0;
-  uint8_t b = mi_bsr32((uint32_t)bsize);
-  if (b <= 1) return bsize;
-  size_t bin = ((b << 1) | (bsize >> (b - 1))&0x01);
+static size_t _mi_binx4(size_t wsize) {
+  size_t bin;
+  if (wsize <= 1) {
+    bin = 1;
+  }
+  else if (wsize <= 8) {
+    // bin = (wsize+1)&~1; // round to double word sizes
+    bin = (uint8_t)wsize;
+  }
+  else {
+    uint8_t b = mi_bsr32((uint32_t)wsize);
+    if (b <= 1) return wsize;
+    bin = ((b << 1) | (wsize >> (b - 1))&0x01) + 3;
+  }
  return bin;
 }

@ -450,22 +459,40 @@ static size_t _mi_binx8(size_t bsize) {
  return bin;
 }

+
+static inline size_t mi_bin(size_t wsize) {
+  uint8_t bin;
+  if (wsize <= 1) {
+    bin = 1;
+  }
+  else if (wsize <= 8) {
+    // bin = (wsize+1)&~1; // round to double word sizes
+    bin = (uint8_t)wsize;
+  }
+  else {
+    wsize--;
+    // find the highest bit
+    uint8_t b = (uint8_t)mi_bsr32((uint32_t)wsize);  // note: wsize != 0
+    // and use the top 3 bits to determine the bin (~12.5% worst internal fragmentation).
+    // - adjust with 3 because we use do not round the first 8 sizes
+    //   which each get an exact bin
+    bin = ((b << 2) + (uint8_t)((wsize >> (b - 2)) & 0x03)) - 3;
+  }
+  return bin;
+}
+
+
 static void mi_bins(void) {
  //printf("  QNULL(1), /* 0 */ \\\n  ");
  size_t last_bin = 0;
-  size_t min_bsize = 0;
-  size_t last_bsize = 0;
-  for (size_t bsize = 1; bsize < 2*1024; bsize++) {
-    size_t size = bsize * 64 * 1024;
-    size_t bin = _mi_binx8(bsize);
+  for (size_t wsize = 1; wsize <= (4*1024*1024) / 8 + 1024; wsize++) {
+    size_t bin = mi_bin(wsize);
    if (bin != last_bin) {
-      printf("min bsize: %6zd, max bsize: %6zd, bin: %6zd\n", min_bsize, last_bsize, last_bin);
-      //printf("QNULL(%6zd), ", wsize);
-      //if (last_bin%8 == 0) printf("/* %i */ \\\n  ", last_bin);
+      //printf("min bsize: %6zd, max bsize: %6zd, bin: %6zd\n", min_wsize, last_wsize, last_bin);
+      printf("QNULL(%6zd), ", wsize-1);
+      if (last_bin%8 == 0) printf("/* %zu */ \\\n  ", last_bin);
      last_bin = bin;
-      min_bsize = bsize;
    }
-    last_bsize = bsize;
  }
 }
 #endif
--- a/test/main-override.cpp
+++ b/test/main-override.cpp
@ -47,8 +47,8 @@ static void test_stl_allocators();


 int main() {
-  // mi_stats_reset();  // ignore earlier allocations
-
+  mi_stats_reset();  // ignore earlier allocations
+  various_tests();
  test_mixed1();
  //test_std_string();
  //test_thread_local();
--- a/test/test-stress.c
+++ b/test/test-stress.c
@ -23,7 +23,7 @@ terms of the MIT license.
 #include <assert.h>

 // #define MI_GUARDED
-// #define USE_STD_MALLOC
+#define USE_STD_MALLOC

 // > mimalloc-test-stress [THREADS] [SCALE] [ITER]
 //
@ -36,13 +36,13 @@ static int ITER    = 400;
 static int THREADS = 8;
 static int SCALE   = 25;
 static int ITER    = 20;
-#elif defined(xMI_GUARDED)     // with debug guard pages reduce parameters to stay within the azure pipeline limits
+#elif defined(MI_GUARDED)     // with debug guard pages reduce parameters to stay within the azure pipeline limits
 static int THREADS = 8;
 static int SCALE   = 10;
 static int ITER    = 10;
 #else
 static int THREADS = 32;      // more repeatable if THREADS <= #processors
-static int SCALE   = 25;      // scaling factor
+static int SCALE   = 50;      // scaling factor
 static int ITER    = 50;      // N full iterations destructing and re-creating all threads
 #endif

@ -50,7 +50,7 @@ static int ITER    = 50;      // N full iterations destructing and re-creating a

 #define STRESS                // undefine for leak test

-static bool   allow_large_objects = true;     // allow very large objects? (set to `true` if SCALE>100)
+static bool   allow_large_objects = false;     // allow very large objects? (set to `true` if SCALE>100)
 static size_t use_one_size = 0;               // use single object size of `N * sizeof(uintptr_t)`?

 static bool   main_participates = false;       // main thread participates as a worker too
@ -326,6 +326,7 @@ int main(int argc, char** argv) {
  #endif
  mi_stats_print(NULL);
 #endif
+  mi_stats_print(NULL);
  //bench_end_program();
  return 0;
 }