MLIR-based convolution and GEMM kernel generator for ROCm

This is the repository for a MLIR-based convolution and GEMM kernel generator targetting AMD hardware. This generator is mainly used from MIGraphX, but it can be used on a standalone basis. (The ability to use this code via torch-mlir is being investigated as well.)

Building (and testing)

To build the system

mkdir build
cd build
cmake -G Ninja .. -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_C_COMPILER=/opt/rocm/llvm/bin/clang -DCMAKE_CXX_COMPILER=/opt/rocm/llvm/bin/clang++
ninja check-rocmlir

Note that we require building against a relatively recent clang. The above commands specify the ROCm clang release in order to match our standard development practice.

To not actually run the tests, use check-rocmlir-build-only.

To build the static library that is used by MIGraphX

mkdir build
cd build
cmake -G Ninja .. -DBUILD_FAT_LIBROCKCOMPILER=On -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=/opt/rocm/llvm/bin/clang -DCMAKE_CXX_COMPILER=/opt/rocm/llvm/bin/clang++
ninja

and to install it so MIGraphX can find it

cmake --install . --prefix [your/MIGraphX/deps/folder/path]

Standalone usage

For usage examples, see mlir/test/rocmlir-driver, especiallly the files sanity.mlir and the contents of the e2e_for_pr directory.

This project also includes code that translates from TOSA to kernels, see mlir/test/fusion for examples of how to invoke it.

In general (with all invocations given from the build directory)

• ./bin/rocmlir-gen generates high-level convolution operations and host code. Many of the options control data layout, size, etc, but some other useful flags are:
  • -mfma=on (which enables mfma usage) (or -wmma=on for gfx11 targets)
  • -mfma=off (which disables mfma usage) (or -wmma=off for gfx11 targets)
  • -ph (which causes host code to be generated)
  • -pv (which makes the host code validtae the results against a reference)
  • -pv_with_gpu (which uses a GPU validator instead)
  • -pr (which prints kkrnel results)
• ./bin/rocmlir-driver is a wrapper around the kernel generation pipeline. Use -c (or --kernel-pipeline=full --host-pipeline=runner) to run the default pipeline

The result of this pipeline should, most simply, be passed to the rocm-run script in mlir/utils/widgets//rocm-run, which calls mlir-cpu-runner with the appropriate flags and infers the pathnames for libraries correctly.

In more detail, the result of the above pipeline can be passed to ./external/llvm-project/llvm/bin/mlir-cpu-runner .

mlir-cpu-runner needs to link the generated host code against libraries that map from MLIR operations to the HIP runtime. The required command-line arguments (if running from build/) are

./external/llvm-project/llvm/bin/mlir-cpu-runner --shared-libs=./external/llvm-project/llvm/lib/libmlir_rocm_runtime.so,./lib/libconv-validation-wrappers.so,./external/llvm-project/llvm/lib/libmlir_runner_utils.so --entry-point-result=void

Adding --debug-only=serialize-to-blob to the rocmlir-driver invocation will cause the GCN assembly code for the kernels being executed to be dumped to standard error.

Disabling MFMA/WMMA in tests

By default, we infer the use of GPU-specific acceleration instructions, like MFMA or WMMA, based on the features of the currently available GPU.

To disable this, add -DROCMLIR_GEN_FLAGS="-mfma=off -wmma=off" to the cmake invocations given above. Note that this will not affect behavior in production/static library builds, which do not use rocmlir-gen.