Metal: don't precompile default shaders.

scripts/code_generation_hashes/Metal_default_shaders.json

@@ -6,49 +6,25 @@
   "src/libANGLE/renderer/gen_angle_format_table.py":
     "34ab57bb88958e320f509bd5fbd04495",
   "src/libANGLE/renderer/metal/shaders/blit.metal":
-    "502660301ee21e5cd4a5dd42a8a24e82",
+    "2f6286729703039d41d0f6a109a23ac2",
   "src/libANGLE/renderer/metal/shaders/clear.metal":
     "37ef05208eb5d12110a7d277a4bbcbe1",
   "src/libANGLE/renderer/metal/shaders/common.h":
-    "0cadef47fb785aa3102acb2a6eae94bb",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_2_1_debug_ios_autogen.inc":
-    "2dfc9dc2496c93fe6c4d46661d77a14b",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_2_1_debug_ios_sim_autogen.inc":
-    "e4d6ce5e3081e18908b8c95f7ed372b2",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_2_1_debug_mac_autogen.inc":
-    "79cb485ee377adac2632adaa21e2c8ac",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_2_1_ios_autogen.inc":
-    "55abd74424bdd88b5523534ec867f715",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_2_1_ios_sim_autogen.inc":
-    "1cf20c8cb47ed5990c8c165b7faa1c0d",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_2_1_mac_autogen.inc":
-    "a4b9067e64c6d0dcfcff3422f833779c",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_debug_ios_autogen.inc":
-    "af51783bbc7dc7d6ad17f88cc5409222",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_debug_ios_sim_autogen.inc":
-    "25e0ecdaf8829af2ebed1738bf57b2d9",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_debug_mac_autogen.inc":
-    "34885f0482b73513f1736eb8be340d66",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_ios_autogen.inc":
-    "f22b1f09a53bc5d1f9a462f4552aa116",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_ios_sim_autogen.inc":
-    "7de301390d329a1493a557c60ac9888c",
-  "src/libANGLE/renderer/metal/shaders/compiled/compiled_default_metallib_mac_autogen.inc":
-    "cd1dbbd9b961aaef467cc24c5c1abcb0",
-  "src/libANGLE/renderer/metal/shaders/compiled/mtl_default_shaders_autogen.inc":
-    "634a127f4e94f6bc3123e89850d010ee",
+    "ac1bdd21a1cee65d88cfc4e0e61894da",
   "src/libANGLE/renderer/metal/shaders/constants.h":
     "dad1a869a1095be669b7da5651901d38",
   "src/libANGLE/renderer/metal/shaders/copy_buffer.metal":
-    "97b258edbade1ed088e4c03a1102f974",
+    "813e16a38d6e3ba858b62a712b1b316d",
   "src/libANGLE/renderer/metal/shaders/format_autogen.h":
     "b1d6512b904a7eb151b0095b7898b0e5",
   "src/libANGLE/renderer/metal/shaders/gen_indices.metal":
-    "87a76d5e12825111c0595f69e79f5d20",
+    "add45aa44305b1a64c4bb8ece1e3d2fc",
   "src/libANGLE/renderer/metal/shaders/gen_mipmap.metal":
     "54dca94c48bead446624079070b9b309",
   "src/libANGLE/renderer/metal/shaders/gen_mtl_internal_shaders.py":
-    "d5f23d645c0cb9d487e40d490414a772",
+    "9f538745533b6bb14fbbc9e4252f31e0",
+  "src/libANGLE/renderer/metal/shaders/mtl_default_shaders_src_autogen.inc":
+    "2a0b015ebec36ee1304ae64a7187abb8",
   "src/libANGLE/renderer/metal/shaders/visibility.metal":
-    "998d705656c63849edd0187cd8062fc7"
+    "b82aa740cf4b0aed606aacef1024beea"
 }
\ No newline at end of file

src/libANGLE/renderer/metal/BUILD.gn

@@ -62,21 +62,9 @@ _metal_backend_sources = [
   "mtl_state_cache.mm",
   "mtl_utils.h",
   "mtl_utils.mm",
-  "shaders/compiled/compiled_default_metallib_2_1_debug_ios_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_2_1_debug_ios_sim_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_2_1_debug_mac_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_2_1_ios_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_2_1_ios_sim_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_2_1_mac_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_debug_ios_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_debug_ios_sim_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_debug_mac_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_ios_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_ios_sim_autogen.inc",
-  "shaders/compiled/compiled_default_metallib_mac_autogen.inc",
-  "shaders/compiled/mtl_default_shaders_autogen.inc",
   "shaders/constants.h",
   "shaders/format_autogen.h",
+  "shaders/mtl_default_shaders_src_autogen.inc",
 ]
 
 config("angle_metal_backend_config") {

src/libANGLE/renderer/metal/DisplayMtl.h

@@ -32,6 +32,8 @@ class ShareGroupMtl : public ShareGroupImpl
 
 class ContextMtl;
 
+struct DefaultShaderAsyncInfoMtl;
+
 class DisplayMtl : public DisplayImpl
 {
   public:
@@ -123,7 +125,7 @@ class DisplayMtl : public DisplayImpl
     mtl::RenderUtils &getUtils() { return mUtils; }
     mtl::StateCache &getStateCache() { return mStateCache; }
 
-    id<MTLLibrary> getDefaultShadersLib() const { return mDefaultShaders; }
+    id<MTLLibrary> getDefaultShadersLib();
 
     id<MTLDepthStencilState> getDepthStencilState(const mtl::DepthStencilDesc &desc)
     {
@@ -175,7 +177,7 @@ class DisplayMtl : public DisplayImpl
     mtl::RenderUtils mUtils;
 
     // Built-in Shaders
-    mtl::AutoObjCPtr<id<MTLLibrary>> mDefaultShaders = nil;
+    std::shared_ptr<DefaultShaderAsyncInfoMtl> mDefaultShadersAsyncInfo;
 #if ANGLE_MTL_EVENT_AVAILABLE
     mtl::AutoObjCObj<MTLSharedEventListener> mSharedEventListener;
 #endif

src/libANGLE/renderer/metal/DisplayMtl.mm

@@ -17,7 +17,7 @@
 #include "libANGLE/renderer/metal/SurfaceMtl.h"
 #include "libANGLE/renderer/metal/SyncMtl.h"
 #include "libANGLE/renderer/metal/mtl_common.h"
-#include "libANGLE/renderer/metal/shaders/compiled/mtl_default_shaders_autogen.inc"
+#include "libANGLE/renderer/metal/shaders/mtl_default_shaders_src_autogen.inc"
 #include "platform/Platform.h"
 
 #include "EGL/eglext.h"
@@ -44,6 +44,18 @@ DisplayImpl *CreateMetalDisplay(const egl::DisplayState &state)
     return new DisplayMtl(state);
 }
 
+struct DefaultShaderAsyncInfoMtl
+{
+    mtl::AutoObjCPtr<id<MTLLibrary>> defaultShaders;
+    mtl::AutoObjCPtr<NSError *> defaultShadersCompileError;
+
+    // Synchronization primitives for compiling default shaders in back-ground
+    std::condition_variable cv;
+    std::mutex lock;
+
+    bool compiled = false;
+};
+
 DisplayMtl::DisplayMtl(const egl::DisplayState &state)
     : DisplayImpl(state), mUtils(this), mGlslangInitialized(false)
 {}
@@ -100,8 +112,8 @@ void DisplayMtl::terminate()
 {
     mUtils.onDestroy();
     mCmdQueue.reset();
-    mDefaultShaders = nil;
-    mMetalDevice    = nil;
+    mDefaultShadersAsyncInfo = nullptr;
+    mMetalDevice             = nil;
 #if ANGLE_MTL_EVENT_AVAILABLE
     mSharedEventListener = nil;
 #endif
@@ -751,48 +763,62 @@ void DisplayMtl::initializeFeatures()
 
 angle::Result DisplayMtl::initializeShaderLibrary()
 {
-    mtl::AutoObjCObj<NSError> err = nil;
+    mDefaultShadersAsyncInfo.reset(new DefaultShaderAsyncInfoMtl);
 
-    const uint8_t *compiled_shader_binary;
-    size_t compiled_shader_binary_len;
+    // Create references to async info struct since it might be released in terminate(), but the
+    // callback might still not be fired yet.
+    std::shared_ptr<DefaultShaderAsyncInfoMtl> asyncRef = mDefaultShadersAsyncInfo;
 
-#if !defined(NDEBUG)
-    if (getFeatures().hasStencilOutput.enabled)
-    {
-        compiled_shader_binary     = compiled_default_metallib_2_1_debug;
-        compiled_shader_binary_len = compiled_default_metallib_2_1_debug_len;
-    }
-    else
-    {
-        compiled_shader_binary     = compiled_default_metallib_debug;
-        compiled_shader_binary_len = compiled_default_metallib_debug_len;
-    }
-#else
-    if (getFeatures().hasStencilOutput.enabled)
+    // Compile the default shaders asynchronously
+    ANGLE_MTL_OBJC_SCOPE
     {
-        compiled_shader_binary     = compiled_default_metallib_2_1;
-        compiled_shader_binary_len = compiled_default_metallib_2_1_len;
+        auto nsSource = [[NSString alloc] initWithBytesNoCopy:gDefaultMetallibSrc
+                                                       length:sizeof(gDefaultMetallibSrc)
+                                                     encoding:NSUTF8StringEncoding
+                                                 freeWhenDone:NO];
+        auto options  = [[[MTLCompileOptions alloc] init] ANGLE_MTL_AUTORELEASE];
+        [getMetalDevice() newLibraryWithSource:nsSource
+                                       options:options
+                             completionHandler:^(id<MTLLibrary> library, NSError *error) {
+                               std::unique_lock<std::mutex> lg(asyncRef->lock);
+
+                               asyncRef->defaultShaders             = std::move(library);
+                               asyncRef->defaultShadersCompileError = std::move(error);
+
+                               asyncRef->compiled = true;
+                               asyncRef->cv.notify_one();
+                             }];
+
+        [nsSource ANGLE_MTL_AUTORELEASE];
     }
-    else
+
+    return angle::Result::Continue;
+}
+
+id<MTLLibrary> DisplayMtl::getDefaultShadersLib()
+{
+    std::unique_lock<std::mutex> lg(mDefaultShadersAsyncInfo->lock);
+    if (!mDefaultShadersAsyncInfo->compiled)
     {
-        compiled_shader_binary     = compiled_default_metallib;
-        compiled_shader_binary_len = compiled_default_metallib_len;
+        // Wait for async compilation
+        mDefaultShadersAsyncInfo->cv.wait(lg,
+                                          [this] { return mDefaultShadersAsyncInfo->compiled; });
     }
-#endif
 
-    mDefaultShaders = CreateShaderLibraryFromBinary(getMetalDevice(), compiled_shader_binary,
-                                                    compiled_shader_binary_len, &err);
-
-    if (err && !mDefaultShaders)
+    if (mDefaultShadersAsyncInfo->defaultShadersCompileError &&
+        !mDefaultShadersAsyncInfo->defaultShaders)
     {
         ANGLE_MTL_OBJC_SCOPE
         {
-            ERR() << "Internal error: " << err.get().localizedDescription.UTF8String;
+            ERR() << "Internal error: "
+                  << mDefaultShadersAsyncInfo->defaultShadersCompileError.get()
+                         .localizedDescription.UTF8String;
         }
-        return angle::Result::Stop;
+        // This is not supposed to happen
+        UNREACHABLE();
     }
 
-    return angle::Result::Continue;
+    return mDefaultShadersAsyncInfo->defaultShaders;
 }
 
 bool DisplayMtl::supportsIOSGPUFamily(uint8_t iOSFamily) const

src/libANGLE/renderer/metal/shaders/blit.metal

@@ -334,7 +334,7 @@ kernel void blitStencilToBufferCS(ushort2 gIndices [[thread_position_in_grid]],
 }
 
 // Fragment's stencil output is only available since Metal 2.1
-#if __METAL_VERSION__ >= 210
+@@#if __METAL_VERSION__ >= 210
 
 struct FragmentStencilOut
 {
@@ -397,4 +397,4 @@ fragment FragmentDepthStencilOut blitDepthStencilFS(
                       srcStencilTextureCube, input.texCoords, options.srcLevel, options.srcLayer);
     return re;
 }
-#endif  // __METAL_VERSION__ >= 210
+@@#endif  // __METAL_VERSION__ >= 210

src/libANGLE/renderer/metal/shaders/common.h

@@ -8,9 +8,10 @@
 #ifndef LIBANGLE_RENDERER_METAL_SHADERS_COMMON_H_
 #define LIBANGLE_RENDERER_METAL_SHADERS_COMMON_H_
 
+// clang-format off
 #ifndef SKIP_STD_HEADERS
-#    include <simd/simd.h>
-#    include <metal_stdlib>
+@@#    include <simd/simd.h>
+@@#    include <metal_stdlib>
 #endif
 
 #include "constants.h"
@@ -22,6 +23,7 @@
     }
 
 using namespace metal;
+// clang-format on
 
 // Common constant defined number of color outputs
 constant uint32_t kNumColorOutputs [[function_constant(0)]];

src/libANGLE/renderer/metal/shaders/copy_buffer.metal

@@ -9,17 +9,17 @@
 // be a pain to implement without the use of macros.
 //
 
-#include <metal_pack>
+@@#include <metal_pack>
 
 #include "common.h"
 #include "format_autogen.h"
 
 using namespace rx::mtl_shader;
 
-constant int kCopyFormatType [[function_constant(1)]];
+constant int kCopyFormatType [[function_constant(10)]];
 
 /* -------- copy pixel data between buffer and texture ---------*/
-constant int kCopyTextureType [[function_constant(2)]];
+constant int kCopyTextureType [[function_constant(20)]];
 constant bool kCopyTextureType2D      = kCopyTextureType == kTextureType2D;
 constant bool kCopyTextureType2DArray = kCopyTextureType == kTextureType2DArray;
 constant bool kCopyTextureType2DMS    = kCopyTextureType == kTextureType2DMultisample;

src/libANGLE/renderer/metal/shaders/gen_indices.metal

@@ -9,10 +9,10 @@
 using namespace rx::mtl_shader;
 
 // function_constant(0) is already used by common.h
-constant bool kSourceBufferAligned[[function_constant(1)]];
-constant bool kSourceIndexIsU8[[function_constant(2)]];
-constant bool kSourceIndexIsU16[[function_constant(3)]];
-constant bool kSourceIndexIsU32[[function_constant(4)]];
+constant bool kSourceBufferAligned[[function_constant(100)]];
+constant bool kSourceIndexIsU8[[function_constant(200)]];
+constant bool kSourceIndexIsU16[[function_constant(300)]];
+constant bool kSourceIndexIsU32[[function_constant(400)]];
 constant bool kSourceBufferUnaligned = !kSourceBufferAligned;
 constant bool kUseSourceBufferU8     = kSourceIndexIsU8 || kSourceBufferUnaligned;
 constant bool kUseSourceBufferU16    = kSourceIndexIsU16 && kSourceBufferAligned;

src/libANGLE/renderer/metal/shaders/gen_mtl_internal_shaders.py

@@ -25,146 +25,6 @@ template_header_boilerplate = """// GENERATED FILE - DO NOT EDIT.
 //
 """
 
-
-# Convert content of a file to byte array and append to a header file.
-# variable_name: name of C++ variable that will hold the file content as byte array.
-# filename: the file whose content will be converted to C++ byte array.
-# dest_src_file: destination header file that will contain the byte array.
-def append_file_as_byte_array_string(variable_name, filename, dest_src_file):
-    string = '// Generated from {0}:\n'.format(filename)
-    string += 'constexpr\nunsigned char {0}[] = {{\n'.format(variable_name)
-    bytes_ = open(filename, "rb").read()
-    byteCounter = 0
-    for byte in bytes_:
-        if byteCounter == 0:
-            string += "  "
-        string += '0x{:02x}'.format(ord(byte)) + ","
-        byteCounter += 1
-        if byteCounter == 12:
-            byteCounter = 0
-            string += "\n"
-        else:
-            string += " "
-
-    string += "\n};\n"
-
-    string += 'constexpr\nsize_t {0}_len = sizeof({0});\n'.format(variable_name)
-
-    with open(dest_src_file, "a") as out_file:
-        out_file.write(string)
-
-
-# Convert content of a file to byte array and store in a header file.
-# variable_name: name of C++ variable that will hold the file content as byte array.
-# copyright_comments: copyright comments
-# filename: the file whose content will be converted to C++ byte array.
-# dest_src_file: destination header file that will contain the byte array.
-def store_file_as_byte_array_string(variable_name, copyright_comments, filename, dest_src_file):
-    os.system("echo \"{0}\" > {1}".format(copyright_comments, dest_src_file))
-
-    append_file_as_byte_array_string(variable_name, filename, dest_src_file)
-
-
-# Convert content of a metallib to byte array and store in a header file, then include this header in
-# mtl_default_shaders_autogen.inc.
-# variable_name: name of C++ variable that will hold the file content as byte array.
-# copyright_comments: copyright comments
-# filename: the metallib file whose content will be converted to C++ byte array.
-def store_metallib_as_byte_array_and_include(variable_name, copyright_comments, filename):
-    array_autogen_filename = "{0}_autogen.inc".format(
-        filename.replace('.metallib', '').replace('.', '_'))
-
-    # Generate a header containing the file's content as C array.
-    store_file_as_byte_array_string(variable_name, copyright_comments, filename,
-                                    array_autogen_filename)
-
-    # Include this file in mtl_default_shaders_autogen.inc
-    # NOTE: filename already includes "compiled/"
-    include_code = '#include "{0}"\n'.format(array_autogen_filename.replace('compiled/', ''))
-    with open('compiled/mtl_default_shaders_autogen.inc', "a") as out_file:
-        out_file.write(include_code)
-
-
-# Compile metal shader.
-# mac_version: target version of macOS
-# ios_version: target version of iOS
-# variable_name: name of C++ variable that will hold the compiled binary data as a C array.
-# additional_flags: additional shader compiler flags
-# src_files: metal source files
-def gen_precompiled_shaders(mac_version, ios_version, variable_name, additional_flags, src_files,
-                            copyright_comments):
-    print('Generating default shaders with flags=\'{0}\' ...'.format(additional_flags))
-
-    # Mac version's compilation
-    print('Compiling macos {0} version of default shaders ...'.format(mac_version))
-
-    mac_metallib = 'compiled/{0}.mac.metallib'.format(variable_name)
-
-    object_files = ''
-    for src_file in src_files:
-        object_file = 'compiled/default.{0}.{1}.air'.format(mac_version, src_file)
-        object_files += ' ' + object_file
-        os.system('xcrun -sdk macosx metal -mmacosx-version-min={0} {1} {2} -c -o {3}'.format(
-            mac_version, additional_flags, src_file, object_file))
-    os.system('xcrun -sdk macosx metallib {object_files} -o {file}'.format(
-        file=mac_metallib, object_files=object_files))
-
-    # iOS device version's compilation
-    print('Compiling ios {0} version of default shaders ...'.format(ios_version))
-
-    ios_metallib = 'compiled/{0}.ios.metallib'.format(variable_name)
-
-    object_files = ''
-    for src_file in src_files:
-        object_file = 'compiled/default.ios.{0}.{1}.air'.format(ios_version, src_file)
-        object_files += ' ' + object_file
-        os.system('xcrun -sdk iphoneos metal -mios-version-min={0} {1} {2} -c -o {3}'.format(
-            ios_version, additional_flags, src_file, object_file))
-    os.system('xcrun -sdk iphoneos metallib {object_files} -o {file}'.format(
-        file=ios_metallib, object_files=object_files))
-
-    # iOS simulator version's compilation
-    print('Compiling ios {0} simulator version of default shaders ...'.format(ios_version))
-
-    ios_sim_metallib = 'compiled/{0}.ios_sim.metallib'.format(variable_name)
-
-    object_files = ''
-    for src_file in src_files:
-        object_file = 'compiled/default.ios_sim.{0}.{1}.air'.format(ios_version, src_file)
-        object_files += ' ' + object_file
-        os.system('xcrun -sdk iphonesimulator metal {0} {1} -c -o {2}'.format(
-            additional_flags, src_file, object_file))
-    os.system('xcrun -sdk iphonesimulator metallib {object_files} -o {file}'.format(
-        file=ios_sim_metallib, object_files=object_files))
-
-    # Mac version's byte array string
-    os.system(
-        'echo "#if TARGET_OS_OSX || TARGET_OS_MACCATALYST\n" >> compiled/mtl_default_shaders_autogen.inc'
-    )
-    store_metallib_as_byte_array_and_include(variable_name, copyright_comments, mac_metallib)
-
-    # iOS simulator version's byte array string
-    os.system(
-        'echo "\n#elif TARGET_OS_IOS && TARGET_OS_SIMULATOR  // TARGET_OS_OSX || TARGET_OS_MACCATALYST\n" >> compiled/mtl_default_shaders_autogen.inc'
-    )
-
-    store_metallib_as_byte_array_and_include(variable_name, copyright_comments, ios_sim_metallib)
-
-    # iOS version's byte array string
-    os.system(
-        'echo "\n#elif TARGET_OS_IOS  // TARGET_OS_OSX || TARGET_OS_MACCATALYST\n" >> compiled/mtl_default_shaders_autogen.inc'
-    )
-
-    store_metallib_as_byte_array_and_include(variable_name, copyright_comments, ios_metallib)
-
-    os.system(
-        'echo "#endif  // TARGET_OS_OSX || TARGET_OS_MACCATALYST\n" >> compiled/mtl_default_shaders_autogen.inc'
-    )
-
-    os.system('rm -rfv compiled/*.air')
-    os.system('rm -rfv compiled/*.metallib')
-
-
 def gen_shader_enums_code(angle_formats):
 
     code = """// This file is similar to src/libANGLE/renderer/FormatID_autogen.h but is used by Metal default
@@ -200,28 +60,10 @@ def main():
         'visibility.metal'
     ]
 
-    # yapf: disable
-    os_specific_autogen_files = [
-        'compiled/compiled_default_metallib_2_1_debug_ios_autogen.inc',
-        'compiled/compiled_default_metallib_2_1_debug_ios_sim_autogen.inc',
-        'compiled/compiled_default_metallib_2_1_debug_mac_autogen.inc',
-        'compiled/compiled_default_metallib_2_1_ios_autogen.inc',
-        'compiled/compiled_default_metallib_2_1_ios_sim_autogen.inc',
-        'compiled/compiled_default_metallib_2_1_mac_autogen.inc',
-        'compiled/compiled_default_metallib_debug_ios_autogen.inc',
-        'compiled/compiled_default_metallib_debug_ios_sim_autogen.inc',
-        'compiled/compiled_default_metallib_debug_mac_autogen.inc',
-        'compiled/compiled_default_metallib_ios_autogen.inc',
-        'compiled/compiled_default_metallib_ios_sim_autogen.inc',
-        'compiled/compiled_default_metallib_mac_autogen.inc',
-    ]
-    # yapf: enable
-
     # auto_script parameters.
     if len(sys.argv) > 1:
         inputs = angle_format_script_files + src_files + ['common.h', 'constants.h']
-        outputs = ['format_autogen.h', 'compiled/mtl_default_shaders_autogen.inc'
-                  ] + os_specific_autogen_files
+        outputs = ['format_autogen.h', 'mtl_default_shaders_src_autogen.inc']
 
         if sys.argv[1] == 'inputs':
             print ','.join(inputs)
@@ -246,28 +88,41 @@ def main():
         out_file.write(shader_autogen_header)
         out_file.close()
 
-    # -------- Compile shaders -----------
-    # boilerplate code
-    os.system("echo \"{0}\" > compiled/mtl_default_shaders_autogen.inc".format(boilerplate_code))
-    os.system(
-        'echo "// Compiled binary for Metal default shaders.\n\n" >> compiled/mtl_default_shaders_autogen.inc'
-    )
-    os.system(
-        'echo "#include <TargetConditionals.h>\n\n" >> compiled/mtl_default_shaders_autogen.inc')
-
-    os.system('echo "// clang-format off" >> compiled/mtl_default_shaders_autogen.inc')
+    # -------- Combine and create shader source string -----------
+    # Generate a combination source
+    os.system('mkdir -p temp && rm -f temp/master_source.metal && touch temp/master_source.metal')
+    for src_file in src_files:
+        os.system('echo "#include \\"../{0}\\"" >> temp/master_source.metal'.format(src_file))
+
+    # Use clang/gcc to preprocess the combination source. "@@" token is used to prevent clang from
+    # expanding the preprocessor directive
+    if os.system('which gcc') == 0:
+        print('combining source files using gcc -E')
+        os.system('gcc -xc++ -E temp/master_source.metal > temp/master_source.metal.pp')
+    else:
+        print('combining source files using clang -E')
+        os.system('clang -xc++ -E temp/master_source.metal > temp/master_source.metal.pp')
+
+    # Remove '@@' tokens
+    final_combined_src_string = ''
+    with open('temp/master_source.metal.pp', 'rt') as in_file:
+        final_combined_src_string = in_file.read().replace('@@', '')
+        in_file.close()
+
+    # Generate final file:
+    with open('mtl_default_shaders_src_autogen.inc', 'wt') as out_file:
+        out_file.write(boilerplate_code)
+        out_file.write('\n')
+        out_file.write('// C++ string version of combined Metal default shaders.\n\n')
+        out_file.write('\n\nstatic char gDefaultMetallibSrc[] = R"(\n')
+        out_file.write(final_combined_src_string)
+        out_file.write('\n')
+        out_file.write(')";\n')
+        out_file.close()
 
-    # pre-compiled shaders
-    gen_precompiled_shaders(10.13, 11.0, 'compiled_default_metallib', '', src_files,
-                            boilerplate_code)
-    gen_precompiled_shaders(10.13, 11.0, 'compiled_default_metallib_debug',
-                            '-gline-tables-only -MO', src_files, boilerplate_code)
-    gen_precompiled_shaders(10.14, 12.0, 'compiled_default_metallib_2_1', '', src_files,
-                            boilerplate_code)
-    gen_precompiled_shaders(10.14, 12.0, 'compiled_default_metallib_2_1_debug',
-                            '-gline-tables-only -MO', src_files, boilerplate_code)
+    # Clean up
+    os.system('rm -rf temp')
 
-    os.system('echo "// clang-format on" >> compiled/mtl_default_shaders_autogen.inc')
 
 
 if __name__ == '__main__':

src/libANGLE/renderer/metal/shaders/visibility.metal

@@ -6,7 +6,7 @@
 
 #include "common.h"
 
-constant bool kCombineWithExistingResult [[function_constant(1)]];
+constant bool kCombineWithExistingResult [[function_constant(1000)]];
 
 // Combine the visibility result of current render pass with previous value from previous render
 // pass