[Build] Using xnnpack fails with "_Float16 is not supported on this target" for iOS x86_64 simulator

[decamp]

Describe the issue

When cross-compiling for iOS simulator x86_64, using the --use_xnnpack setting causes build to fail. It looks like maybe the build configuration is trying to rely on missing _Float16 support.

Build machine: M1 MacBook pro, MacOS 15.0
Xcode: 16.0
Clang: 16.0.0 (clang-1600.0.26.3)
Cmake: 3.30.4
onnxruntime: c24e55b1f140a2fc3d584738422313d436f122d6

Urgency

No response

Target platform

iOS x86_64 (simulator)

Build script

tools/ci_build/github/apple/build_and_assemble_apple_pods.py \
 --include-ops-by-config model.config \
 --build-settings-file build-settings.json

build-settings.json:

{
  "build_osx_archs": {
    "iphonesimulator": ["x86_64"]
  },
  "build_params": {
    "base": [
      "--parallel",
      "--build_apple_framework",
      "--use_coreml",
      "--skip_tests",
      "--cmake_extra_defines=onnxruntime_BUILD_UNIT_TESTS=OFF"
    ],
    "iphonesimulator": [
      "--ios",
      "--use_xcode",
      "--use_xnnpack",
      "--apple_deploy_target=13.0"
    ]
  }
}

Error / output

PrecompileModule /Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/_math-EBU1MF3V4Y9NGBY750RC4B1Q2.scan
    cd /Users/name/code/vendor/onnxruntime/cmake
    builtin-precompileModule /Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/_math-EBU1MF3V4Y9NGBY750RC4B1Q2.scan
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -cc1 -fdiagnostics-show-note-include-stack -fmacro-backtrace-limit\=0 -fmessage-length\=295 -ferror-limit 19 -serialize-diagnostic-file /Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/_math-EBU1MF3V4Y9NGBY750RC4B1Q2.dia -fcolor-diagnostics -fsystem-module -fmodule-map-file\=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator18.0.sdk/usr/include/DarwinFoundation.modulemap -fmodule-map-file\=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator18.0.sdk/usr/include/os_availability.modulemap -o /Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/_math-EBU1MF3V4Y9NGBY750RC4B1Q2.pcm -disable-free -emit-module -x c /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/include/c_standard_library.modulemap -tune-cpu generic -target-cpu core2 -target-feature +sse -target-feature -sse2 -triple x86_64-apple-ios13.0.0-simulator -target-linker-version 1115.7.3 -target-sdk-version\=18.0 -fmodules-validate-system-headers -fno-modules-prune-non-affecting-module-map-files -fno-modulemap-allow-subdirectory-search -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator18.0.sdk -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/16 -fmodule-file\=DarwinFoundation\=/Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/DarwinFoundation-6XBV9A52YVKP0OEUX88WZ9WT8.pcm -fmodule-file\=os_availability\=/Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/os_availability-7M09FJPGLX0VX34H2VI5UFU21.pcm -isystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/16/include -internal-externc-isystem /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator18.0.sdk/usr/include -ivfsstatcache /var/folders/8t/7gch98kn3k15rj57hs17p9900000gn/C/com.apple.DeveloperTools/16.0-16A242d/Xcode/SDKStatCaches.noindex/iphonesimulator18.0-22A3362-db63dc9361471f152f572502bdbfe70a.sdkstatcache -std\=c99 -fasm-blocks -fmodules -fmodule-name\=_math -fmodules-search-all -fno-implicit-modules -fmax-type-align\=16 -mdarwin-stkchk-strong-link -fno-odr-hash-protocols -pic-level 2 -disable-objc-default-synthesize-properties -stack-protector 1 -fgnuc-version\=4.2.1 -fblocks -ffp-contract\=off -fclang-abi-compat\=4.0 -fno-experimental-relative-c++-abi-vtables -fno-file-reproducible -clang-vendor-feature\=+disableNonDependentMemberExprInCurrentInstantiation -clang-vendor-feature\=+enableAggressiveVLAFolding -clang-vendor-feature\=+revert09abecef7bbf -clang-vendor-feature\=+thisNoAlignAttr -clang-vendor-feature\=+thisNoNullAttr -clang-vendor-feature\=+disableAtImportPrivateFrameworkInImplementationError -O2 -fcommon -fno-sanitize-address-use-odr-indicator -fno-sanitize-memory-param-retval -fmerge-all-constants -fno-verbose-asm -fregister-global-dtors-with-atexit -fno-use-init-array -funique-basic-block-section-names -fsplit-dwarf-inlining -gno-codeview-command-line -gstrict-dwarf -gno-column-info -llvm-verify-each -no-struct-path-tbaa -fexperimental-assignment-tracking\=disabled -no-enable-noundef-analysis -stack-protector-buffer-size 0 -finline-functions -fno-unroll-loops -gpubnames -fdiagnostics-hotness-threshold\=0 -fdiagnostics-misexpect-tolerance\=0 -fno-split-cold-code -D CMAKE_INTDIR\=\"Release-iphonesimulator\" -D EIGEN_MPL2_ONLY -D FXDIV_USE_INLINE_ASSEMBLY\=0 -D NDEBUG -D ORT_ENABLE_STREAM -D REDUCED_OPS_BUILD -D XNN_ENABLE_ARM_BF16\=1 -D XNN_ENABLE_ARM_DOTPROD\=1 -D XNN_ENABLE_ARM_FP16_SCALAR\=1 -D XNN_ENABLE_ARM_FP16_VECTOR\=1 -D XNN_ENABLE_ARM_I8MM\=1 -D XNN_ENABLE_ASSEMBLY\=1 -D XNN_ENABLE_AVX256SKX\=1 -D XNN_ENABLE_AVX256VNNI\=1 -D XNN_ENABLE_AVX256VNNIGFNI\=1 -D XNN_ENABLE_AVX512AMX\=1 -D XNN_ENABLE_AVX512FP16\=1 -D XNN_ENABLE_AVX512VNNIGFNI\=1 -D XNN_ENABLE_AVXVNNI\=1 -D XNN_ENABLE_CPUINFO\=1 -D XNN_ENABLE_DWCONV_MULTIPASS\=0 -D XNN_ENABLE_GEMM_M_SPECIALIZATION\=1 -D XNN_ENABLE_HVX\=1 -D XNN_ENABLE_KLEIDIAI\=0 -D XNN_ENABLE_MEMOPT\=1 -D XNN_ENABLE_RISCV_VECTOR\=1 -D XNN_ENABLE_SPARSE\=1 -D XNN_ENABLE_VSX\=1 -D XNN_LOG_LEVEL\=0 -D __GCC_HAVE_DWARF2_CFI_ASM\=1 -MT moduledependenciestarget -dependency-file /Users/name/code/vendor/onnxruntime/build/apple_framework/intermediates/iphonesimulator_x86_64/Release/build/ExplicitPrecompiledModules/_math-EBU1MF3V4Y9NGBY750RC4B1Q2.d -skip-unused-modulemap-deps
While building module '_math':
In file included from <module-includes>:1:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/include/math.h:614:27: error: _Float16 is not supported on this target
  614 | extern _Float16 __fabsf16(_Float16) __API_AVAILABLE(macos(15.0), ios(18.0), watchos(11.0), tvos(18.0));
      |                           ^
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/include/math.h:614:8: error: _Float16 is not supported on this target
  614 | extern _Float16 __fabsf16(_Float16) __API_AVAILABLE(macos(15.0), ios(18.0), watchos(11.0), tvos(18.0));
      |        ^
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/include/math.h:615:28: error: _Float16 is not supported on this target
  615 | extern _Float16 __hypotf16(_Float16, _Float16) __API_AVAILABLE(macos(15.0), ios(18.0), watchos(11.0), tvos(18.0));
      |                            ^

And so on...

It might be relevant that: -D XNN_ENABLE_AVX512FP16\=1.

Visual Studio Version

No response

GCC / Compiler Version

No response

[skottmckay]

Seems to be an XNNPACK issue. Not sure why no fix has been directly added there. We will look into it.

google/XNNPACK#6989

[skottmckay]

I think Xcode 16 is also a factor. I don't see an issue with Xcode 14.7 cross-compiling on an M1.

[vraspar]

It seems to be issue with FP16 dependency. I verified that this PR fixes the above issue: Maratyszcza/FP16#32.