3 [![Build Status](https://travis-ci.org/xianyi/OpenBLAS.png?branch=develop)](https://travis-ci.org/xianyi/OpenBLAS)
6 OpenBLAS is an optimized BLAS library based on GotoBLAS2 1.13 BSD version. OpenBLAS is an open source project supported by Lab of Parallel Software and Computational Science, ISCAS <http://www.rdcps.ac.cn>.
8 Please read the documents on OpenBLAS wiki pages <http://github.com/xianyi/OpenBLAS/wiki>.
11 Download from project homepage. http://xianyi.github.com/OpenBLAS/
13 Or, check out codes from git://github.com/xianyi/OpenBLAS.git
15 * type "make" to detect the CPU automatically.
17 * type "make TARGET=xxx" to set target CPU, e.g. "make TARGET=NEHALEM". The full target list is in file TargetList.txt.
20 Please set CC and FC with the cross toolchains. Then, set HOSTCC with your host C compiler. At last, set TARGET explicitly.
24 On X86 box, compile this library for loongson3a CPU.
26 make BINARY=64 CC=mips64el-unknown-linux-gnu-gcc FC=mips64el-unknown-linux-gnu-gfortran HOSTCC=gcc TARGET=LOONGSON3A
32 ### Install to the directory (optional)
36 make install PREFIX=your_installation_directory
38 The default directory is /opt/OpenBLAS
41 Please read GotoBLAS_01Readme.txt
43 ### Additional support CPU:
46 - **Intel Xeon 56xx (Westmere)**: Used GotoBLAS2 Nehalem codes.
47 - **Intel Sandy Bridge**: Optimized Level-3 BLAS with AVX on x86-64.
48 - **Intel Haswell**: Optimized Level-3 BLAS with AVX on x86-64 (identical to Sandy Bridge).
49 - **AMD Bobcat**: Used GotoBLAS2 Barcelona codes.
50 - **AMD Bulldozer**: x86-64 S/DGEMM AVX kernels. (Thank Werner Saar)
51 - **AMD PILEDRIVER**: Used Bulldozer codes.
54 - **ICT Loongson 3A**: Optimized Level-3 BLAS and the part of Level-1,2.
55 - **ICT Loongson 3B**: Experimental
59 - **MingWin/Windows**: Please read <https://github.com/xianyi/OpenBLAS/wiki/How-to-use-OpenBLAS-in-Microsoft-Visual-Studio>.
60 - **Darwin/Mac OS X**: Experimental. Although GotoBLAS2 supports Darwin, we are the beginner on Mac OS X.
61 - **FreeBSD**: Supported by community. We didn't test the library on this OS.
64 Link with libopenblas.a or -lopenblas for shared library.
66 ### Set the number of threads with environment variables.
70 export OPENBLAS_NUM_THREADS=4
74 export GOTO_NUM_THREADS=4
78 export OMP_NUM_THREADS=4
80 The priorities are OPENBLAS_NUM_THREADS > GOTO_NUM_THREADS > OMP_NUM_THREADS.
82 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.
84 ### Set the number of threads on runtime.
86 We provided the below functions to control the number of threads on runtime.
88 void goto_set_num_threads(int num_threads);
90 void openblas_set_num_threads(int num_threads);
92 If you compile this lib with USE_OPENMP=1, you should use the above functions, too.
95 Please add a issue in https://github.com/xianyi/OpenBLAS/issues
98 * OpenBLAS users mailing list: https://groups.google.com/forum/#!forum/openblas-users
99 * OpenBLAS developers mailing list: https://groups.google.com/forum/#!forum/openblas-dev
102 Please see Changelog.txt to obtain the differences between GotoBLAS2 1.13 BSD version.
105 * Please read [Faq](https://github.com/xianyi/OpenBLAS/wiki/Faq) at first.
106 * Please use gcc version 4.6 and above to compile Sandy Bridge AVX kernels on Linux/MingW/BSD.
107 * 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.
108 * The number of CPUs/Cores should less than or equal to 256.
109 * On Linux, OpenBLAS sets the processor affinity by default. This may cause [the conflict with R parallel](https://stat.ethz.ch/pipermail/r-sig-hpc/2012-April/001348.html). You can build the library with NO_AFFINITY=1.
110 * 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.
112 ## Specification of Git Branches
113 We used the git branching model in this article (http://nvie.com/posts/a-successful-git-branching-model/).
114 Now, there are 4 branches in github.com.
115 * The master branch. This a main branch to reflect a production-ready state.
116 * The develop branch. This a main branch to reflect a state with the latest delivered development changes for the next release.
117 * The loongson3a branch. This is a feature branch. We develop Loongson3A codes on this branch. We will merge this feature to develop branch in future.
118 * The gh-pages branch. This is for web pages