OpenBLAS

This is a fork of the OpenBLAS and has been improved performance for the FUJITSU A64FX processor.

The following routine is tuned for A64FX.

• SGEMM

Prerequisites

• GNU Compiler Collection 10.2 or higher

Installation

Download the source code

• Clone this repository.

$ git clone https://github.com/fujitsu/OpenBLAS.git

Build and install OpenBLAS for A64FX

Notice

• To make a library for A64FX, specify TARGET=A64FX at make command,
• In the following descriptions, $INSTALL_PATH is the name of the directory in which to install the OpenBLAS libraries and header files.

Build and install the sequential library

$ make CC=gcc TARGET=A64FX
$ make CC=gcc TARGET=A64FX install PREFIX=$INSTALL_PATH

Build and install threaded parallel Library parallelized with OpenMP

$ make USE_OPENMP=1 CC=gcc TARGET=A64FX
$ make USE_OPENMP=1 CC=gcc TARGET=A64FX install PREFIX=$INSTALL_PATH

Build and install ILP64 sequential library

$ make CC=gcc TARGET=A64FX INTERFACE64=1
$ make CC=gcc TARGET=A64FX INTERFACE64=1 install PREFIX=$INSTALL_PATH

Build and install ILP64 threaded parallel Library parallelized with OpenMP

$ make USE_OPENMP=1 CC=gcc TARGET=A64FX INTERFACE64=1
$ make USE_OPENMP=1 CC=gcc TARGET=A64FX INTERFACE64=1 install PREFIX=$INSTALL_PATH

Usage

To use the OpenBLAS library, add -lopenblas as an option when linking user programs. Also, use the -L and -I options to specify the directory where you installed the libraries and header files.

How to compile

• For Fortran programs

$ gfortran a.f -L$INSTALL_PATH/lib -lopenblas

• For C programs

$ gcc a.c -I$INSTALL_PATH/include -L$INSTALL_PATH/lib  -lopenblas

It is recommended to use large pages for performance. For Technical Computing Suite environments, HPC extension large page library can be used by adding -L/opt/FJSVxos/mmm/lib64 -lmpg -Wl,-T/opt/FJSVxos/mmm/util/bss-2mb.lds to the options. Specify this option before any other libraries.

gcc  a.c -L/opt/FJSVxos/mmm/lib64 -lmpg -Wl,-T/opt/FJSVxos/mmm/util/bss-2mb.lds -I$INSTALL_PATH/include -L$INSTALL_PATH/lib  -lopenblas

Performance

The OpenBLAS library in this product improves the performance of SGEMM as follows:

Library	Routine	Parameters	# of cores	Original OpenBLAS	OpenBLAS tuned for A64FX
Sequential	SGEMM	No Transpose, M=N=K=5000	1 core	78 GFlops	108 GFlops
OpenMP	SGEMM	No Transpose, M=N=K=10000	12 cores	827 GFlops	1267 GFlops

Restrictions

None.

License

• See LICENSE file.