Overview

chipStar (formerly CHIP-SPV) is software that allows software written to use the Heterogeneous-compute Interface for Portability (HIP) interface and kernel language to target GPUs via the SPIR-V intermediate language. chipStar can use either the Intel Level Zero runtime or an OpenCL runtime as a backend.

This repository contains support for building chipStar and its dependencies via the Spack package manager.

Note: most development to date has been done with the Level Zero environment, and it is expected that substantial work is needed for the environment targeting the OpenCL backend to work.

Prerequisites

• An x86_64 system running a common Linux distribution. OpenSLES 15 is the best tested to date.
• A working Spack installation.
• A recent Clang installation that is registered with Spack as a compiler. Versions 15 and 16 are best tested, but 14 might work. We suggest installing the compiler via Spack (i.e., by installing something like llvm@16.0.2 and then using spack compiler add with the llvm package's install location), because the chipstar package defined in this repository depends on the llvm package anyway.
• A recent (at least version 2023.1) Intel OneAPI compiler installation that is registered with Spack as a compiler. The recommended way of doing this is by installing the Spack intel-oneapi-compilers package, then registering the location of its compilers with Spack. E.g.,

$ spack install intel-oneapi-compilers@2023
$ spack compiler add $(spack location -i intel-oneapi-compilers@2023)/compiler/latest/linux

Usage

0. Clone this repository to the target system.

$ git clone https://github.com/CHIP-SPV/CHIP-SPV-Spack

2. Activate the environment you want to build. E.g., for the environment that just builds chipStar with Level Zero backend:

$ cd CHIP-SPV-Spack/Environments/LevelZero
$ spack env activate .

3. Concretize the active environment. (In Spack terminology, "to concretize" means to let Spack examine the package specifications it has been asked to build, plus the available package repositories, resolve dependencies and check constraints, and decide exactly which packages it will build, in which order, and with which configuration.)

$ spack concretize -f -U

We suggest examining the output from running the spack concretize command to make sure that Spack's concretizer has truly decided to use the configuration options and especially the compilers that you want it to use. Note that the environment and related configuration are purposefully not overly constrained to use the given compiler for every dependency package, so even though there are some packages that must be built with %clang, there are others that may be built (or re-used from already-installed packages) using %gcc such as the system's GCC installation.

If Spack's concretizer didn't do what you want, you can re-concretize the environment and be more explicit about what you want using command-line configuration options (recommended) or by editing the environment's spack.yaml file or other configuration options that your Spack installation is using. (Use spack config blame to see which configuration files Spack is using.) For instance, if you have both clang@16.0.2 and clang@15.0.7 installed and registered as Spack compilers, and you want to build using clang@15.0.7, you may have to use a concretize command like the following:

$ spack -c "packages:chipstar:require:'%clang@15.0.7'" concretize -f -U

As before, verify from the output of the spack concretize command that it is using the compiler version you want, clang@15.0.7 in this example.

4. Build the environment.

$ spack install

Spack supports some options for controlling the build and installation, such as -j to limit the number of processes used for parallel builds, useful for being a good citizen on shared systems by not allowing Spack to use all available cores (its default). See the Spack documentation for more information.

Assuming all goes well with the build and install, a spack find should show the packages that you just built.

5. Use the installed software. There are several ways you might update your environment to use the software, including:

• spack load chipstar
• Activating the environment that you used to build the software
• If your Spack configuration is such that it can generate module files and module files have been generated for the software you built via this environment, module load chipstar

Note that you may need to modify your environment to be able to run programs produced using chipStar and the H4I libraries built using this Spack repository. For instance, on some systems, one must load the intel_compute_runtime module before being able to run programs that use the Intel Level Zero runtime.

TODO

• Clean up and verify the OpenCL-based environment.
• Ensure the OpenCL-based environment can use any OpenCL implementation.
• Incorporate H4I HIP libraries like H4I-HipBLAS into an environments.
• Support using the software installed by the environment via module command.