nixpkgs/pkgs/development/libraries/science/math/atlas/default.nix
2014-09-21 11:00:24 -05:00

77 lines
3.2 KiB
Nix

{ stdenv, fetchurl, gfortran, tolerateCpuTimingInaccuracy ? true, shared ? false
, cpuConfig ? if stdenv.isi686 then "-b 32 -A 18 -V 1" else "-b 64 -A 31 -V 384"
}:
# Atlas detects the CPU and optimizes its build accordingly. This is great when
# the code is run on the same machine that built the binary, but in case of a
# central build farm like Hydra, this feature is dangerous because the code may
# be generated utilizing fancy features that users who download the binary
# cannot execute.
#
# To avoid these issues, the build is configured using the 'cpuConfig'
# parameter as follows:
#
# | x86 CPU | x86_64 CPU |
# |---------------------------------------------+------------------------|
# | -b 32 | -b 64 |
# | -A 18 (Pentium II) | -A 31 (Athlon K7) |
# | -V 1 (No SIMD: Pentium II doesn't have SSE) | -V 384 (SSE1 and SSE2) |
#
# Users who want to compile a highly optimized version of ATLAS that's suitable
# for their local machine can override these settings accordingly.
#
# The -V flags can change with each release as new instruction sets are added
# because upstream thinks it's a good idea to add entries at the start of an
# enum, rather than the end. If the build suddenly fails with messages about
# missing instruction sets, you may need to poke around in the source a bit.
let
version = "3.10.2";
optionalString = stdenv.lib.optionalString;
optional = stdenv.lib.optional;
in
stdenv.mkDerivation {
name = "atlas-${version}";
src = fetchurl {
url = "mirror://sourceforge/math-atlas/atlas${version}.tar.bz2";
sha256 = "0bqh4bdnjdyww4mcpg6kn0x7338mfqbdgysn97dzrwwb26di7ars";
};
buildInputs = [ gfortran ];
# Atlas aborts the build if it detects that some kind of CPU frequency
# scaling is active on the build machine because that feature offsets the
# performance timings. We ignore that check, however, because with binaries
# being pre-built on Hydra those timings aren't accurate for the local
# machine in the first place.
patches = optional tolerateCpuTimingInaccuracy ./disable-timing-accuracy-check.patch;
# Configure outside of the source directory.
preConfigure = '' mkdir build; cd build; configureScript=../configure; '';
# * -fPIC is passed even in non-shared builds so that the ATLAS code can be
# used to inside of shared libraries, like Octave does.
#
# * -t 0 disables use of multi-threading. It's not quite clear what the
# consequences of that setting are and whether it's necessary or not.
configureFlags = "-Fa alg -fPIC -t 0 ${cpuConfig}" + optionalString shared " --shared";
doCheck = true;
meta = {
homepage = "http://math-atlas.sourceforge.net/";
description = "Automatically Tuned Linear Algebra Software (ATLAS)";
license = stdenv.lib.licenses.bsd3;
longDescription = ''
The ATLAS (Automatically Tuned Linear Algebra Software) project 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.
'';
};
}