[Build] WASM build of v1.20.1 with --use_xnnpack fails

[raphaelmenges]

Describe the issue

Hello 👋

I want to utilize the ONNX runtime in a Web application. I successfully built the static library of ONNX runtime with SIMD and threading and linked it within my Emscripten project. The CPU execution providers works great. Now I tried to also include the XNNPACK execution provider with the --use_xnnpack flag to improve the performance of the inferencing.

However, the src/amalgam directory is missing from the XNNPACK distribution. xnnpack.cmake says:

# See source lists in _deps/googlexnnpack-src/BUILD.bazel for wasm_prod_microkernels

I cannot find any documentation at the XNNPACK how to manually generate these amalgam (?) microkernels. I also cannot find an example in this repository. How to build the XNNPACK execution provider for the Web?

Urgency

No response

Target platform

WASM

Build script

onnxruntime/build.sh \
    --build_dir ./onnxruntime-build \
    --config Release \
    --build_wasm_static_lib \
    --enable_wasm_simd \
    --enable_wasm_threads \
    --skip_tests \
    --disable_wasm_exception_catching \
    --disable_rtti \
    --use_xnnpack \
    --parallel

Error / output

CMake Error at external/xnnpack.cmake:189 (target_sources):
  Cannot find source file:

    ./onnxruntime-build/Release/_deps/googlexnnpack-src/src/amalgam/gen/scalar.c

  Tried extensions .c .C .c++ .cc .cpp .cxx .cu .mpp .m .M .mm .ixx .cppm
  .ccm .cxxm .c++m .h .hh .h++ .hm .hpp .hxx .in .txx .f .F .for .f77 .f90
  .f95 .f03 .hip .ispc
Call Stack (most recent call first):
  external/onnxruntime_external_deps.cmake:566 (include)
  CMakeLists.txt:614 (include)

Visual Studio Version

No response

GCC / Compiler Version

No response

[raphaelmenges]

Apparently there was an update of the XNNPACK dependency in b94ba09 from google/XNNPACK@0da379f to google/XNNPACK@309b75c. The old version of the XNNPACK dependency still contained the src/amalgam directory. As I understand it, this directory could be created once but there is no more such a script.