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<!---======================= begin_copyright_notice ============================ Copyright (C) 2020-2021 Intel Corporation SPDX-License-Identifier: MIT ============================= end_copyright_notice ==========================-->VC Intrinsics
Introduction
VC Intrinsics project contains a set of new intrinsics on top of core LLVM IR instructions that represent SIMD semantics of a program targeting GPU. This set is now used by
- CMC - https://github.com/intel/cm-compiler
- DPC++ - https://github.com/intel/llvm
- ISPC - https://github.com/ispc/ispc
frontend compilers and
- IGC VC backend - https://github.com/intel/intel-graphics-compiler
License
VC Intrinsics are distributed under the MIT license.
You may obtain a copy of the License at:
https://opensource.org/licenses/MIT
Dependencies
Source code
- LLVM Project - https://github.com/llvm/llvm-project
Tools
To build libraries:
- CMake - https://cmake.org/ - 3.13.4 or later
- Python - https://www.python.org/ - 2.7 or later
- C++ compiler - anything that can compile LLVM
To build documentation:
- Sphinx - https://www.sphinx-doc.org - 1.5 or later
- GNU Make - https://www.gnu.org/software/make/ - 3.79 or later
- Standard Unix utilities (mkdir, rm, sed)
Building
VC Intrinsics can be built in two major modes: in-tree and external. All major LLVM versions starting from LLVM 8 are supported.
LLVM ToT can be used too, but there is no guarantee that it will always work (because of sudden breaking changes in LLVM C++ API). However, maintainers are trying to fix such issues as fast as possible.
In-tree build
For in-tree build VC Intrinsics can be considered as an external LLVM
project. Put VC Intrinsics source directory inside llvm/projects
directory or add -DLLVM_EXTERNAL_PROJECTS="vc-intrinsics" -DLLVM_EXTERNAL_VC_INTRINSICS_SOURCE_DIR=<vc-intrinsics> to cmake
command arguments when configuring LLVM.
External build
To configure VC Intrinsics with prebuilt LLVM run cmake as follows:
$ cmake -DLLVM_DIR=<llvm install>/lib/cmake/llvm <vc-intrinsics>
Documentation
VC Intrinsics documentation is inside docs subdirectory and can be
built using Sphinx. To build html version do the following:
$ cd docs
$ make -f Makefile.sphinx html
This will extract comments from main intrinsics description and
generate readable html output in _build/html subdirectory.
Testing
VC Intrinsics repository contains lit tests that are enabled when
-DVC_INTR_ENABLE_LIT_TESTS=ON is passed to cmake command. Lit tests
use LLVM plugins and currently are supported only with dynamic LLVM
(when LLVM is configured with -DLLVM_LINK_LLVM_DYLIB=ON). In
external build path to lit utility should be specified as follows:
-DLLVM_EXTERNAL_LIT=<lit>. Full example with external build:
$ cmake -DLLVM_DIR=<llvm install>/lib/cmake/llvm -DVC_INTR_ENABLE_LIT_TESTS=ON -DLLVM_EXTERNAL_LIT=<lit> <vc-intrinsics>
Target check-vc-intrinsics will run lit tests.
How to provide feedback
Please submit an issue using native github.com interface: https://github.com/intel/vc-intrinsics/issues.
How to contribute
Create a pull request on github.com with your patch. A maintainer will contact you if there are questions or concerns.