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diff --git a/libraries/atlas/README.SLACKWARE b/libraries/atlas/README.SLACKWARE new file mode 100644 index 0000000000000..3d7d9be243a3d --- /dev/null +++ b/libraries/atlas/README.SLACKWARE @@ -0,0 +1,100 @@ +ATLAS (Automatically Tuned Linear Algebra Software) is an ongoing +research effort focusing on applying empirical techniques in order to +provide portable performance. At present, it provides C and Fortran77 +interfaces to a portably efficient BLAS implementation, as well as a few +routines from LAPACK. + +IMPORTANT NOTES: + +1) Please note that the present SlackBuild for ATLAS does by no means + try to take into account all configuration/build issues of ATLAS. + Nevertheless, the relevant patches mentioned in the ATLAS Errata + are applied. + +2) The script takes advantage of the fact that the compilers shipped with + Slackware should be OK. It also assumes that you are installing on an x86 + or x86_64 platform. If you decide to use other compilers or install on + another platform, you are unfortunately on your own and welcome to suggest + improvements or patches to this SlackBuild. Moreover, there is no "post + install" tuning performed. + +3) ATLAS does not conflict with the reference netlib BLAS (see also note 6). + Nevertheless, if ATLAS got installed successfully you should consider removing + netlib BLAS and (re)compiling every BLAS dependent package (starting with + LAPACK) against ATLAS. Otherwise you may not have much gain from installing + ATLAS and may even get into problems (see next note). + +4) There is a strong interaction between ATLAS and LAPACK. If you want to install + ATLAS just for testing and avoid problems with LAPACK you are urged to make + use of the SYS_DESTDIR variable as explained later. Otherwise consider the + following: + a) It is not recommended to install LAPACK just along ATLAS, i.e. without building + it against ATLAS. Moreover, if LAPACK is already installed you have to first + remove it and later on build it against ATLAS. + b) If ATLAS+LAPACK doesn't work for you, just stick with (netlib) BLAS+LAPACK. + Netlib BLAS is also available as a SlackBuild. + c) If ATLAS+LAPACK is installed you have to recompile and reinstall LAPACK after + each ATLAS upgrade. + +5) ATLAS conflicts with cblas. + +6) You have to have netlib BLAS installed before you install ATLAS. As stated + above, you should consider removing it from your system afterwards. + +INSTALLATION DETAILS: + +1) Make sure CPU throttling is off before starting the install. This is + important, since ATLAS has to tune itself. + +2) For the same reason, keep the load on the system as low as possible + while building ATLAS. + +3) There are a few extra variables which you may want or need + to give appropriate values when calling the atlas.SlackBuild: + MAX_MALLOC, REF_BLAS, USE_ARCH_DEFAULTS, SYS_DESTDIR and + DEFAULT_DOCS. + + MAX_MALLOC is for adjusting the maximal size IN BYTES(!) that ATLAS + is allowed to allocate. According to the ATLAS errata, a too small + value may strongly reduce threaded performance. The default value + within this SlackBuild corresponds to 256MB. (The default value in + the ATLAS source corresponds to 64MB.) + + REF_BLAS defaults to the full path to the netlib BLAS library as + installed from the appropriate SlackBuilds.org script. If you have + the netlib BLAS elsewhere, you have to set the appropriate + value to this variable. + + USE_ARCH_DEFAULTS defaults to "yes", which means that the library + will be optimized by trying to take into account former builds done + on a similar machine. Thus ATLAS will use predefined optimizations + if available. This may reduce (much) the compilation time but may + not give you the best result if you don't use the same compiler + version (gcc 4.2) as the ATLAS author. + Please note that with this variable set to "no", or if there are no + known optimizations for your machine ATLAS compilation lasts for + about three hours! Take a nap :-) + + SYS_DESTDIR is set by default to "/usr" and is the system destination + directory. When installing the package produced by this SlackBuild, + ATLAS's files will be written to $SYS_DESTDIR/include, + $SYS_DESTDIR/include/atlas and $SYS_DESTDIR/lib (or lib64). + Documentation files are written to /usr/doc/atlas-$VERSION if not + otherwise stated (see below). + You may want to change the value of SYS_DESTDIR to avoid conflicts (see + IMPORTANT NOTES above). IMPORTANT: SYS_DESTDIR has to have an absolute + path as value. + + DEFAULT_DOCS has the default value "yes", which means that docs go + to /usr/doc/atlas-$VERSION, but you may want to let the docs to + go to $SYS_DESTDIR/doc/atlas-$VERSION. For this, just set this + variable to something like "no". + + All these settings may be done the usual way on the command line when + calling this SlackBuild, you do not have to edit the script. + +If you also installed the LAPACK linked against ATLAS, consider the following: +"IMPORTANT: If you are actually updating this library, i.e. ATLAS, you MUST also +rebuild and reinstall LAPACK, even if there is no update available for LAPACK! +Otherwise you end up with an broken/incomplete LAPACK library! + |