build against openblas on supported arches

generating configure for 3.4.0+ requires new libtool

arpack.spec

@@ -1,10 +1,17 @@
 %global commit b0f7a6008f37f913e97f67c826fc37fa9758f626
 %global shortcommit %(c=%{commit}; echo ${c:0:7})
+%if 0%{?fedora} >= 26
+%{!?openblas_arches:%global openblas_arches x86_64 %{ix86} armv7hl %{power64} aarch64}
+%ifnarch %{openblas_arches}
+# matches openblas ExclusiveArch
+%bcond_without atlas
+%endif
+%endif
 
 
 Name:		arpack
 Version:	3.5.0
-Release:	1%{dist}
+Release:	2%{dist}
 Summary:	Fortran 77 subroutines for solving large scale eigenvalue problems
 
 License:	BSD
@@ -13,8 +20,12 @@ URL:		https://github.com/opencollab/arpack-ng
 Source0:	https://github.com/opencollab/arpack-ng/archive/%{version}/arpack-ng-%{version}.tar.gz
 
 BuildRequires:	gcc-gfortran
+%if %{with atlas}
 BuildRequires:	atlas-devel
-BuildRequires:	libtool
+%else
+BuildRequires:	openblas-devel
+%endif
+BuildRequires:	libtool >= 2.4.2
 Provides:	arpack-ng = %{version}-%{release}
 Provides:	arpack-ng%{?_isa} = %{version}-%{release}
 
@@ -69,18 +80,20 @@ autoreconf -vif
 
 
 %build
-export F77=gfortran
+%if %{with atlas}
 %if 0%{?fedora} || 0%{?rhel} >= 7
 %global blaslib -L%{_libdir}/atlas -ltatlas
 %else
 %global blaslib -L%{_libdir}/atlas -lf77blas -latlas
 %endif
+%else
+%global blaslib -lopenblasp
+%endif
 %configure --enable-shared --enable-static \
     --with-blas="%{blaslib}" \
     --with-lapack="%{blaslib}"
 %make_build
 
-
 %install
 %make_install
 # Get rid of .la files
@@ -118,6 +131,10 @@ pushd EXAMPLES ; make clean ; popd
 
 
 %changelog
+* Mon Jul 03 2017 Dominik Mierzejewski <rpm@greysector.net> - 3.5.0-2
+- build against openblas on supported arches
+- generating configure for 3.4.0+ requires new libtool
+
 * Sat May 20 2017 Björn Esser <besser82@fedoraproject.org> - 3.5.0-1
 - Update to 3.5.0 (#1451525)
 - Drop stuff needed for el5