/OpenBLAS

OpenBLAS is an optimized BLAS library based on GotoBLAS2 1.13 BSD version.

Primary LanguageFORTRANBSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

OpenBLAS

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Introduction

OpenBLAS is an optimized BLAS library based on GotoBLAS2 1.13 BSD version.

Please read the documents on OpenBLAS wiki pages http://github.com/xianyi/OpenBLAS/wiki.

Binary Packages

We provide binary packages for the following platform.

  • Windows x86/x86_64

You can download them from file hosting on sourceforge.net.

Installation from Source

Download from project homepage. http://xianyi.github.com/OpenBLAS/

Or, check out codes from git://github.com/xianyi/OpenBLAS.git

Normal compile

  • type "make" to detect the CPU automatically. or
  • type "make TARGET=xxx" to set target CPU, e.g. "make TARGET=NEHALEM". The full target list is in file TargetList.txt.

Cross compile

Please set CC and FC with the cross toolchains. Then, set HOSTCC with your host C compiler. At last, set TARGET explicitly.

Examples:

On X86 box, compile this library for loongson3a CPU.

make BINARY=64 CC=mips64el-unknown-linux-gnu-gcc FC=mips64el-unknown-linux-gnu-gfortran HOSTCC=gcc TARGET=LOONGSON3A

On X86 box, compile this library for loongson3a CPU with loongcc (based on Open64) compiler.

make CC=loongcc FC=loongf95 HOSTCC=gcc TARGET=LOONGSON3A CROSS=1 CROSS_SUFFIX=mips64el-st-linux-gnu-   NO_LAPACKE=1 NO_SHARED=1 BINARY=32

Debug version

make DEBUG=1

Install to the directory (optional)

Example:

make install PREFIX=your_installation_directory

The default directory is /opt/OpenBLAS

Support CPU & OS

Please read GotoBLAS_01Readme.txt

Additional support CPU:

x86/x86-64:

  • Intel Xeon 56xx (Westmere): Used GotoBLAS2 Nehalem codes.
  • Intel Sandy Bridge: Optimized Level-3 and Level-2 BLAS with AVX on x86-64.
  • Intel Haswell: Optimized Level-3 and Level-2 BLAS with AVX2 and FMA on x86-64.
  • AMD Bobcat: Used GotoBLAS2 Barcelona codes.
  • AMD Bulldozer: x86-64 ?GEMM FMA4 kernels. (Thank Werner Saar)
  • AMD PILEDRIVER: Uses Bulldozer codes with some optimizations.
  • AMD STEAMROLLER: Uses Bulldozer codes with some optimizations.

MIPS64:

  • ICT Loongson 3A: Optimized Level-3 BLAS and the part of Level-1,2.
  • ICT Loongson 3B: Experimental

ARM:

  • ARMV6: Optimized BLAS for vfpv2 and vfpv3-d16 ( e.g. BCM2835, Cortex M0+ )
  • ARMV7: Optimized BLAS for vfpv3-d32 ( e.g. Cortex A8, A9 and A15 )

ARM64:

  • ARMV8: Experimental
  • ARM Cortex-A57: Experimental

Support OS:

Usages

Link with libopenblas.a or -lopenblas for shared library.

Set the number of threads with environment variables.

Examples:

export OPENBLAS_NUM_THREADS=4

or

export GOTO_NUM_THREADS=4

or

export OMP_NUM_THREADS=4

The priorities are OPENBLAS_NUM_THREADS > GOTO_NUM_THREADS > OMP_NUM_THREADS.

If you compile this lib with USE_OPENMP=1, you should set OMP_NUM_THREADS environment variable. OpenBLAS ignores OPENBLAS_NUM_THREADS and GOTO_NUM_THREADS with USE_OPENMP=1.

Set the number of threads on runtime.

We provided the below functions to control the number of threads on runtime.

void goto_set_num_threads(int num_threads);

void openblas_set_num_threads(int num_threads);

If you compile this lib with USE_OPENMP=1, you should use the above functions, too.

Report Bugs

Please add a issue in https://github.com/xianyi/OpenBLAS/issues

Contact

ChangeLog

Please see Changelog.txt to obtain the differences between GotoBLAS2 1.13 BSD version.

Troubleshooting

  • Please read Faq at first.
  • Please use gcc version 4.6 and above to compile Sandy Bridge AVX kernels on Linux/MingW/BSD.
  • Please use Clang version 3.1 and above to compile the library on Sandy Bridge microarchitecture. The Clang 3.0 will generate the wrong AVX binary code.
  • The number of CPUs/Cores should less than or equal to 256. On Linux x86_64(amd64), there is experimental support for up to 1024 CPUs/Cores and 128 numa nodes if you build the library with BIGNUMA=1.
  • OpenBLAS does not set processor affinity by default. On Linux, you can enable processor affinity by commenting the line NO_AFFINITY=1 in Makefile.rule. But this may cause the conflict with R parallel.
  • On Loongson 3A. make test would be failed because of pthread_create error. The error code is EAGAIN. However, it will be OK when you run the same testcase on shell.

Contributing

  1. Check for open issues or open a fresh issue to start a discussion around a feature idea or a bug.
  2. Fork the OpenBLAS repository to start making your changes.
  3. Write a test which shows that the bug was fixed or that the feature works as expected.
  4. Send a pull request. Make sure to add yourself to CONTRIBUTORS.md.

Donation

Please read this wiki page.