From 4b56608674a9c7977cad88ce3f03a9fcb72c93bc Mon Sep 17 00:00:00 2001
From: Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>
Date: Fri, 22 May 2015 16:48:05 +0200
Subject: [PATCH] gnu: python-numpy: Build against OpenBLAS.

* gnu/packages/python.scm (python-numpy)[inputs]: Use "openblas" instead of
  "atlas" when not on MIPS.
* gnu/packages/python.scm (python-numpy)[arguments]: Configure build against
  OpenBLAS unless "atlas" is among the inputs.
---
 gnu/packages/python.scm | 38 ++++++++++++++++++++++++++++----------
 1 file changed, 28 insertions(+), 10 deletions(-)

diff --git a/gnu/packages/python.scm b/gnu/packages/python.scm
index 0916a75..c96296f 100644
--- a/gnu/packages/python.scm
+++ b/gnu/packages/python.scm
@@ -2283,7 +2283,9 @@ writing C extensions for Python as easy as Python itself.")
     (build-system python-build-system)
     (inputs
      `(("python-nose" ,python-nose)
-       ("atlas" ,atlas)))
+       ,(if (string-prefix? "mips" (%current-system))
+            `("atlas" ,atlas)
+            `("openblas" ,openblas))))
     (native-inputs
      `(("gfortran" ,gfortran-4.8)))
     (arguments
@@ -2291,16 +2293,32 @@ writing C extensions for Python as easy as Python itself.")
        (alist-cons-before
         'build 'set-environment-variables
         (lambda* (#:key inputs #:allow-other-keys)
-          (let* ((atlas-threaded
-                  (string-append (assoc-ref inputs "atlas")
-                                 "/lib/libtatlas.so"))
-                 ;; On single core CPUs only the serial library is created.
-                 (atlas-lib
-                  (if (file-exists? atlas-threaded)
-                      atlas-threaded
+          (if (assoc-ref inputs "atlas")
+              ;; Link against Atlas
+              (let* ((atlas-threaded
                       (string-append (assoc-ref inputs "atlas")
-                                     "/lib/libsatlas.so"))))
-            (setenv "ATLAS" atlas-lib)))
+                                     "/lib/libtatlas.so"))
+                     ;; On single core CPUs only the serial library is created.
+                     (atlas-lib
+                      (if (file-exists? atlas-threaded)
+                          atlas-threaded
+                          (string-append (assoc-ref inputs "atlas")
+                                         "/lib/libsatlas.so"))))
+                (setenv "ATLAS" atlas-lib))
+              ;; Link against OpenBLAS
+              (begin
+                (call-with-output-file "site.cfg"
+                  (lambda (port)
+                    (format port "[openblas]
+libraries = openblas
+library_dirs = ~a/lib
+include_dirs = ~a/include
+" (assoc-ref inputs "openblas") (assoc-ref inputs "openblas"))))
+                ;; Use "gcc" executable, not "cc".
+                (substitute* "numpy/distutils/system_info.py"
+                  (("c = distutils\\.ccompiler\\.new_compiler\\(\\)")
+                   "c = distutils.ccompiler.new_compiler(); c.set_executables(compiler='gcc',compiler_so='gcc',linker_exe='gcc',linker_so='gcc -shared')"))))
+          #t)
         ;; Tests can only be run after the library has been installed and not
         ;; within the source directory.
         (alist-cons-after
-- 
2.1.0