IREE LLVM Sandbox

DISCLAIMER: This is not an officially-supported Google project. It is a sandbox for quick iteration and experimentation on projects related to the IREE project, MLIR, and LLVM.

This repository contains experimental work by the IREE team closely related to LLVM and MLIR, usually with the aim of upstreaming in some form. The main project is at https://github.com/google/iree.

As an experimental project, build greenness, documentation, and polish are likely to be minimal, as it instead prioritizes easy experimentation.

License

Licensed under the Apache license with LLVM Exceptions. See LICENSE for more information.

Build instructions

This project builds as part of the LLVM External Projects facility (see documentation for the LLVM_EXTERNAL_PROJECTS config setting). There are many ways to set this up. We recommend using our configure.py script below.

It is left to the reader to adapt paths if deviating. We assume below that projects are checked out to $HOME/src.

Check out projects

TODO: Simplify instructions.

In your $HOME/src directory, check out each project:

Required:

• git clone https://github.com/google/iree-llvm-sandbox

We use the following environment variables defaults in these instructions:

• IREE_LLVM_SANDBOX_SOURCE_DIR: $HOME/src/iree-llvm-sandbox
• IREE_LLVM_SANDBOX_BUILD_DIR: ${IREE_LLVM_SANDBOX_SOURCE_DIR}/build

Python prerequisites (if using Python)

Follow the instructions for MLIR Python Bindings:

which python
python -m venv ~/.venv/mlirdev
source ~/.venv/mlirdev/bin/activate
python -m pip install --upgrade pip
python -m pip install -r requirements.txt

Configure and build.

The sandbox can be optionally built with or without IREE integration (for accessing IREE specific IR and evaluating on IREE compatible targets):

Building with IREE.

Checkout the IREE GitHub repo next to this directory and initialize submodules:

(cd .. && git clone https://github.com/google/iree --recurse-submodules=third_party/llvm-project)

And configure/build the project:

python configure.py --iree-path=../iree

Note that the third_party/llvm-project bundled with IREE will be used.

Building without IREE.

You must checkout llvm-project at a compatible commit.

(cd .. && git clone https://github.com/llvm/llvm-project.git)

And configure/build the project. By default the configure.py script will look in ${IREE_LLVM_SANDBOX_SOURCE_DIR}/../llvm-project (this can also be overridden with --llvm-path):

python configure.py

Using the Python API

source .env && export PYTHONPATH

# Sanity check (should not error).
python -c "import mlir.iree_sandbox"

# Run a matmul.
export MLIR_RUNNER_UTILS_LIB=${IREE_LLVM_SANDBOX_BUILD_DIR}/lib/libmlir_runner_utils.so; \
cd ${IREE_LLVM_SANDBOX_SOURCE_DIR}; \
python -m python.matmul.test

Using mlir-proto-opt

"${IREE_LLVM_SANDBOX_BUILD_DIR}"/bin/mlir-proto-opt \
  ../iree-llvm-sandbox/test/test_constant.mlir \
  -linalg-comprehensive-module-bufferize

TODOs:

1. hook up a lit test target.
2. re-add npcomp instructions once it is upgraded to use the same build setup.

Python-driven parameter search

Python tests come with a tool to perform as simple randomized search. The search is going to randomly instantiate a given op to some cocnrete dimensions and type variables and try to compile it using mlir.

The results are persisted in the output/ folder by default in a structure that includes a name of the expert compiler, the name of the op and the success/failure/timeout status code. The results contain the full program output (including potential compilation errors) and an accompanying .sh file that can be used to re-run the same configuration again.

Collecting random measurements

To run the search with default settings:

export PATH="${IREE_LLVM_SANDBOX_BUILD_DIR}/bin:$PATH"
cd ${IREE_LLVM_SANDBOX_SOURCE_DIR}
alias search_cli="python -m python.local_search.search_cli"
search_cli

To run with a different linalg op, use --op flag:

search_cli --op matvec

To specify the name of the expert compilers, use --expert (see experts.py for all available expert definitions):

search_cli --experts ExpertCompiler1

To specify the possible types, use --types flag:

search_cli --types f32,f64

Alternatively, one can also force some variables to concrete values, while others will ramain random using --assign:

search_cli --assign M=16 N=32 K=64

To specify range of possible values for dimensions, use --range flag (where numbers correspond to arguments of the corresponding range function in Python):

search_cli --range 128,256,8

The search can be run using multiple processes at once, via --par flag:

search_cli --par 72

Each process collects the fixed number of random samples, customized via --samples flag:

search_cli --samples 100

Showing ranked results

One can see a ranked list, based on llvm-mca performance estimates:

alias rank_cli="python -m python.local_search.rank_cli"
rank_cli

You can customize the --op, the number of the output results (--limit) and the metric used for ranking (--by) through additional command-line flags.

The metrics are coming from either runtime or mca input files that can be specified using --input flag. By default results are ranked by the measured runtime.