build_ubuntu.md

Intel® Graphics Compiler for OpenCL™

Ubuntu build section

1. Prepare workspace

Building IGC needs flex, bison, libz and cmake version at least 3.13.4. You can install required packages on Ubuntu using this command:

$ sudo apt-get install flex bison libz-dev cmake

Some of the incoming git operations will try to download and apply patches. For this purpose it is necessary to setup git credentials if they are not already in the git configuration:

$ git config --global user.name "FirstName LastName"
$ git config --global user.email "your@email.com"

2. Install LLVM, LLD, Clang and OpenCL Clang

Important notice Every LLVM/LLD/Clang version brings some restrictions and in some cases needs different configuration. Please refer to LLVM/LLD/Clang version information section for more information.

In this step you need to prepare VC Intrinsics, SPIRV-LLVM Translator, LLVM, LLD, OpenCL-Clang libraries and Clang for IGC. It can be done either by using packaged releases or building those yourself:

Use preinstalled packages

For LLVM, LLD and Clang packages please visit this link to download and install desired version. For apt package manager you can use this command:

$ sudo apt-get install llvm-11 llvm-11-dev clang-11 liblld-11 liblld-11-dev libllvmspirvlib11 libllvmspirvlib-dev

As of now OpenCL Clang is still needed to be built and installed manually. Sources are available here. You can use out-of-tree build method with LLVM and Clang preinstalled. VC Intrinsics is a lightweight library that is built from sources with IGC and there is no package for it.

Installing LLVM, Clang, and OpenCL Clang components means you no longer have to download their sources alongside IGC, so the workspace tree in the next step may look like this:

<workspace>
      |- igc                          https://github.com/intel/intel-graphics-compiler
      |- vc-intrinsics                https://github.com/intel/vc-intrinsics
      |- SPIRV-Tools                  https://github.com/KhronosGroup/SPIRV-Tools
      |- SPIRV-Headers                https://github.com/KhronosGroup/SPIRV-Headers

Additionaly, you can use SPIRV-Tools prebuild package. In order to do that be sure to pass to cmake command IGC_OPTION__SPIRV_TOOLS_MODE=Prebuilds. When SPIRV-Tools are set to Prebuilds you may also use SPIRV-Headers prebuild package with the cmake option IGC_OPTION__USE_PREINSTALLED_SPIRV_HEADERS=ON. Mind that until the issue KhronosGroup/SPIRV-Tools#3909 will not be resolved, we support SPIRV_Tools only as a shared lib, and we encourage to build SPIRV-Tools prebuild with SPIRV_TOOLS_BUILD_STATIC=OFF flag.

Moreover, OpenCL Clang and Vector Compiler share the SPIRV-LLVM Translator library. SPIRV-LLVM Translator cannot be built if OpenCL-Clang is taken as prebuilt from system. This can lead to problems with linking.

Build from sources

Download all dependencies and create workspace. You can use following commands for setup:

$ cd <workspace>
$ git clone https://github.com/intel/vc-intrinsics vc-intrinsics
$ git clone -b llvmorg-11.1.0 https://github.com/llvm/llvm-project llvm-project
$ git clone -b ocl-open-110 https://github.com/intel/opencl-clang llvm-project/llvm/projects/opencl-clang
$ git clone -b llvm_release_110 https://github.com/KhronosGroup/SPIRV-LLVM-Translator llvm-project/llvm/projects/llvm-spirv
$ git clone https://github.com/KhronosGroup/SPIRV-Tools.git SPIRV-Tools
$ git clone https://github.com/KhronosGroup/SPIRV-Headers.git SPIRV-Headers

These commands will set up a workspace with LLVM 11. If you wish to use any other version please refer to the component revision table

Correct directory tree looks like this:

<workspace>
    |- igc              https://github.com/intel/intel-graphics-compiler
    |- vc-intrinsics    https://github.com/intel/vc-intrinsics
    |- SPIRV-Tools      https://github.com/KhronosGroup/SPIRV-Tools
    |- SPIRV-Headers    https://github.com/KhronosGroup/SPIRV-Headers
    |- llvm-project     https://github.com/llvm/llvm-project
        |- llvm/projects/opencl-clang    https://github.com/intel/opencl-clang
        |- llvm/projects/llvm-spirv      https://github.com/KhronosGroup/SPIRV-LLVM-Translator

All dependencies will be built in the next step.

Additional notes on build modes

There are several flags for these builds modes that you can pass to cmake command.

• IGC_OPTION__LLVM_PREFERRED_VERSION -- sets version of LLVM that will be used by IGC (defaults to "11.1.0").
• IGC_OPTION__LLVM_MODE -- select LLVM mode for IGC to use. Possible values are: Source, Prebuilds or empty (that is default). Source mode uses LLVM sources to build LLVM in-tree with IGC. In Prebuilds mode IGC will search for prebuild LLVM package. If mode is empty then default search procedure will happen: IGC will try Source mode first, then fall back to Prebuilds mode. Each mode has suboptions to control IGC behavior.

Source mode has the following suboptions:

• IGC_OPTION__LLVM_STOCK_SOURCES -- whether non-patched LLVM will be used or not (by default OFF).
• IGC_OPTION__LLVM_SOURCES_DIR -- path to llvm sources when building with LLVM sources (by default IGC takes whatever can be found on the same directory level like in example above).

Prebuilds mode has only one suboption (that is default CMake variable):

• LLVM_ROOT -- additional paths to search for LLVM -- these are searched before system paths.

For more detailed info about every mode see:

1. Source mode (see source build);
2. Prebuilds mode (see build with packages).

3. Build and install IGC

1. Download sources:

$ cd <workspace>
$ git clone https://github.com/intel/intel-graphics-compiler igc
  [If using specific release]
$ cd igc && git checkout -b tag igc-<version>

2. Prepare workspace and build

If you are using Use preinstalled packages method IGC will link with installed dependencies dynamically. If you are using Build from sources method IGC will automatically build all dependencies (provided that the workspace structure is preserved) and link statically to LLVM and OpenCL Clang.

You can use following commands to build IGC:

$ cd <workspace>
$ mkdir build
$ cd build
$ cmake ../igc
$ make -j`nproc`

3. Install IGC:

$ sudo make install

---

LLVM/LLD/Clang version information

Version Overview

Version	Product quality
LLVM 12-15	Experimental
LLVM 11	Production
LLVM 10 and older	Experimental

Terminology	Description
Production	Current production version; Builds are verified internally
Experimental	No quality expectations

Revision table

LLVM version determines what branches are used when building dependencies. When checking out the components refer to the following table, replace XX with the LLVM version used:

Repository name	Version specific	Branch	LLVM 11 example
llvm-project	-	release/XX.x	release/11.x
vc-intrinsics	no	master	master
SPIRV-Tools	no	master	master
SPIRV-Headers	no	master	master
SPIRV-LLVM-Translator	yes	llvm_release_XX0	llvm_release_110
opencl-clang	yes	ocl-open-XX0	ocl-open-110

LLVM/LLD/Clang version specific caveats

Some LLVM versions require special steps to build successfully.

LLVM7/Clang7

In the OpenCL Clang project there are patches for Clang. If the Clang you are using to build IGC does not have these patches (for example, when you are using prebuilt packages) it is necessary to add -DVME_TYPES_DEFINED=FALSE to IGC CMake flags.

VectorComplier must be disabled by adding -DIGC_BUILD__VC_ENABLED=OFF to CMake flags.

LLVM8/Clang8

We recommend building LLVM8/Clang8 from sources instead for using prebuilds, because packaged Clang8 is missing these patches:

• 0001-OpenCL-Change-type-of-block-pointer-for-OpenCL.patch
• 0002-OpenCL-Simplify-LLVM-IR-generated-for-OpenCL-blocks.patch
• 0003-OpenCL-Fix-assertion-due-to-blocks.patch

which are needed for enqueue_kernel.

VectorComplier must be disabled by adding -DIGC_BUILD__VC_ENABLED=OFF to CMake flags.

LLVM9/Clang9

No additional steps are needed.

LLVM10/Clang10

No additional steps are needed.

LLVM11/Clang11

No additional steps are needed.

LLVM12/Clang12 to LLVM15/Clang15

Experimental Currently there are none LLVM12+/Clang12+ conformance/performance guarantees.