Commit Graph

8 Commits

Author SHA1 Message Date
Matthew Bauer
5a500ff0ba blas,lapack: use correct name for library
To match the soname, we need to use libblas.so.3, liblapack.so.3.
2020-04-22 12:37:04 -05:00
Matthew Bauer
8f58fa044d blas,lapack: symlink headers when using mkl
Some of these are necessary for things like python.pkgs.numexpr
2020-04-21 00:30:44 -05:00
Matthew Bauer
0caa375b4c blas,lapack: provide symlink for libmkl_rt.so
This is needed for numpy to detect mkl correctly.
2020-04-20 23:47:10 -05:00
Matthew Bauer
ff2f2644f8 blas,lapack: use isILP64 instead of is64bit
This is a better name since we have multiple 64-bit things that could
be referred to.

LP64  : integer=32, long=64, pointer=64
ILP64 : integer=64, long=64, pointer=64
2020-04-20 16:02:43 -05:00
Matthew Bauer
3c9c894f83 blas,lapack: don’t patchelf
We have some unused RPATHs we don’t want shrunk. These are used in MKL
to dlopen based on architecture.
2020-04-20 15:50:28 -05:00
Sébastien Maret
712bf551d8 blas: fix build on darwin 2020-04-19 23:07:10 +02:00
Milan Pässler
fc5090b315 blas: fix build 2020-04-18 03:06:47 +02:00
Matthew Bauer
43873351ff blas/lapack: add wrapper for “alternative”s of BLAS/LAPACK provider
This is based on previous work for switching between BLAS and LAPACK
implementation in Debian[1] and Gentoo[2]. The goal is to have one way
to depend on the BLAS/LAPACK libraries that all packages must use. The
attrs “blas” and “lapack” are used to represent a wrapped BLAS/LAPACK
provider. Derivations that don’t care how BLAS and LAPACK are
implemented can just use blas and lapack directly. If you do care what
you get (perhaps for some CPP), you should verify that blas and lapack
match what you expect with an assertion.

The “blas” package collides with the old “blas” reference
implementation. This has been renamed to “blas-reference”. In
addition, “lapack-reference” is also included, corresponding to
“liblapack” from Netlib.org.

Currently, there are 3 providers of the BLAS and LAPACK interfaces:

- lapack-reference: the BLAS/LAPACK implementation maintained by netlib.org
- OpenBLAS: an optimized version of BLAS and LAPACK
- MKL: Intel’s unfree but highly optimized BLAS/LAPACK implementation

By default, the above implementations all use the “LP64” BLAS and
LAPACK ABI. This corresponds to “openblasCompat” and is the safest way
to use BLAS/LAPACK. You may received some benefits from “ILP64” or
8-byte integer BLAS at the expense of breaking compatibility with some
packages.

This can be switched at build time with an override like:

    import <nixpkgs> {
        config.allowUnfree = true;
        overlays = [(self: super: {
          lapack = super.lapack.override {
            lapackProvider = super.lapack-reference;
          };
          blas = super.blas.override {
            blasProvider = super.lapack-reference;
          };
        })];
      }

or, switched at runtime via LD_LIBRARY_PATH like:

    $ LD_LIBRARY_PATH=$(nix-build -E '(with import <nixpkgs> {}).lapack.override { lapackProvider = pkgs.mkl; is64bit = true; })')/lib:$(nix-build -E '(with import <nixpkgs> {}).blas.override { blasProvider = pkgs.mkl; is64bit = true; })')/lib ./your-blas-linked-binary

By default, we use OpenBLAS LP64 also known in Nixpkgs as
openblasCompat.

[1]: https://wiki.debian.org/DebianScience/LinearAlgebraLibraries
[2]: https://wiki.gentoo.org/wiki/Blas-lapack-switch
2020-04-17 16:23:55 -05:00