Welcome to the Aurora OpenMP Offloading Documentation!
This Project's aim is, to create a prototype infrastructure to offload
OpenMP target code written in C to NEC's new SX-Aurora VE architecture.
It uses Clang as driver and host compiler, libomptarget, NEC's AVEO
interface to run the code on the VE. As compiler the target code, the
project can work with NEC's ncc compiler or with a Clang compiler which
supports VE as a target for LLVM.
Usage
To compile a source file which contains target code for the VE
architecture with ncc as target compiler, compile the source code with
this project's Clang and set the OpenMP target triple to
aurora-nec-veort-unknown e.g.
clang -fopenmp -fopenmp-targets=aurora-nec-veort-unknown input.c
More information can be found in the Usage section.
Overview
To provide OpenMP offloading to SX-Aurora VE devices with Clang as host compiler, this project provides the following components:
- A version of LLVM, modified so that Clang can recognize a new target triple for the VE architecture (Regardless of whether Clang/LLVM is actually used as target compiler).
- A modified version of Clang that can invoke the projects source transformation tool and a target compiler for offloading. As part of the Clang repository:
- A source transformation tool to extract target code from an input file and rewrite it as input for a target compiler.
- A set of wrapper tools that Clang can call to automatically transform and compile the input code with the selected target compiler.
- A plugin for LLVM's libomptarget which offloads the target code at runtime using NEC's AVEO API.
All these components are provided within a single llvm-project repository.