[Buildroot] [PATCH v5 3/3] package/armadillo: allow to select between lapack or openblas

[Gwenhael Goavec-Merou]

Arnout, all,

On Sun, 25 Jul 2021 13:12:31 +0200
"Arnout Vandecappelle (Essensium/Mind)" <arnout at mind.be> wrote:

> From: Gwenhael Goavec-Merou <gwenhael.goavec-merou at trabucayre.com>
> 
> armadillo can use lapack or openblas as BLAS provider. LAPACK support is
> optional.
> 
> This patch
> - adds an _ARCH_SUPPORTS variable to check if one is available
> - adds an option to choose lapack or openblas as BLAS provider
> 
> The choice is required since applications may potentially need lapack.
> 
> Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou at trabucayre.com>
> Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
> ---
> Changes v4 -> v5: [Done by Arnout]
> - Consistent naming of BR2_PACKAGE_ARMADILLO_OPENBLAS (Yann E. Morin)
> - Remove double dependency on lapack/clapack (Yann E. Morin)
> - Remove stray 'endchoice'
> - "Solve" circular dependency by removing clapack
> Changes v3 -> v4: [Done by Arnout]
> - Split off lapack/clapack arch depends in separate patches
> - Simplify the comments (no need for the powerpc complexity)
> - Remove the choices because clapack/lapack choice doesn't work. Keep a
>   single config for openblas.
> Changes v2 -> v3:
> - drop all default statements for choice (Thomas)
> - add explicit -l since blas libary is called liblas for (c)lapack and
>   libopenblas for openblas (Thomas)
> - add a choice for lapack selection between lapack, clapack or none
> Changes v1 -> v2:
> - add openblas as blas provider
> ---
>  package/armadillo/Config.in    | 34 ++++++++++++++++++++++++++--------
>  package/armadillo/armadillo.mk | 18 +++++++++++++++++-
>  2 files changed, 43 insertions(+), 9 deletions(-)
> 
> diff --git a/package/armadillo/Config.in b/package/armadillo/Config.in
> index b2b61a3233..7aed4fd02f 100644
> --- a/package/armadillo/Config.in
> +++ b/package/armadillo/Config.in
> @@ -1,20 +1,38 @@
>  comment "armadillo needs a toolchain w/ C++"
> +	depends on BR2_PACKAGE_OPENBLAS_ARCH_SUPPORTS
blas may be provided by lapack too: maybe it's required to add the same condition
as armadillo itself ?
>  	depends on !BR2_INSTALL_LIBSTDCPP
> -	depends on !BR2_powerpc
> -	depends on !BR2_m68k_cf
>  
> -comment "armadillo needs a glibc toolchain w/ C++"
> -	depends on BR2_powerpc
> -	depends on !BR2_INSTALL_LIBSTDCPP || BR2_TOOLCHAIN_USES_UCLIBC
> +comment "armadillo needs a toolchain w/ fortran, C++"
fortran is only required if lapack has to be used: if lapack is said as optional this is
maybe not required ?
> +	depends on !BR2_PACKAGE_OPENBLAS_ARCH_SUPPORTS # otherwise, see comment above
> +	depends on BR2_PACKAGE_LAPACK_ARCH_SUPPORTS
> +	depends on !BR2_TOOLCHAIN_HAS_FORTRAN || !BR2_INSTALL_LIBSTDCPP
>  
>  config BR2_PACKAGE_ARMADILLO
>  	bool "armadillo"
> +	depends on BR2_PACKAGE_OPENBLAS_ARCH_SUPPORTS || \
> +		(BR2_PACKAGE_LAPACK_ARCH_SUPPORTS && BR2_TOOLCHAIN_HAS_FORTRAN)
>  	depends on BR2_INSTALL_LIBSTDCPP
> -	depends on !BR2_powerpc || BR2_TOOLCHAIN_USES_GLIBC # clapack
> -	depends on !BR2_m68k_cf # clapack
> -	select BR2_PACKAGE_CLAPACK
>  	help
>  	  Armadillo: An Open Source C++ Linear Algebra Library for
>  	  Fast Prototyping and Computationally Intensive Experiments.
>  
>  	  http://arma.sourceforge.net/
> +
> +if BR2_PACKAGE_ARMADILLO
> +
> +choice
> +	prompt "BLAS implementation"
> +
> +config BR2_PACKAGE_ARMADILLO_OPENBLAS
> +	bool "openblas"
> +	depends on BR2_PACKAGE_OPENBLAS_ARCH_SUPPORTS
> +	select BR2_PACKAGE_OPENBLAS
> +
> +config BR2_PACKAGE_ARMADILLO_LAPACK
> +	bool "lapack"
> +	depends on BR2_PACKAGE_LAPACK_ARCH_SUPPORTS && BR2_TOOLCHAIN_HAS_FORTRAN
> +	select BR2_PACKAGE_LAPACK
> +
> +endchoice
> +
> +endif
> diff --git a/package/armadillo/armadillo.mk b/package/armadillo/armadillo.mk
> index 624b842ef6..dcac2bf8cd 100644
> --- a/package/armadillo/armadillo.mk
> +++ b/package/armadillo/armadillo.mk
> @@ -7,11 +7,27 @@
>  ARMADILLO_VERSION = 9.900.2
>  ARMADILLO_SOURCE = armadillo-$(ARMADILLO_VERSION).tar.xz
>  ARMADILLO_SITE = https://downloads.sourceforge.net/project/arma
> -ARMADILLO_DEPENDENCIES = clapack
>  ARMADILLO_INSTALL_STAGING = YES
>  ARMADILLO_LICENSE = Apache-2.0
>  ARMADILLO_LICENSE_FILES = LICENSE.txt
>  
>  ARMADILLO_CONF_OPTS = -DDETECT_HDF5=false
>  
> +# blas support may be provided by lapack (libblas.a) or openblas (libopenblas.a)
> +ARMADILLO_CONF_OPTS += -DBLAS_FOUND=ON
> +ifeq ($(BR2_PACKAGE_ARMADILLO_OPENBLAS),y)
> +ARMADILLO_CONF_OPTS += -DBLAS_LIBRARIES=-lopenblas
> +ARMADILLO_DEPENDENCIES = openblas
> +else
> +# Since BR2_PACKAGE_LAPACK is selected in this case, the dependency on it is
> +# added below.
> +ARMADILLO_CONF_OPTS += -DBLAS_LIBRARIES=-lblas
> +endif
> +
> +# lapack support is optional and can only be provided by lapack, not openblas
> +ifeq ($(BR2_PACKAGE_LAPACK),y)
> +ARMADILLO_CONF_OPTS += -DLAPACK_FOUND=ON
> +ARMADILLO_DEPENDENCIES += lapack
> +endif
> +
>  $(eval $(cmake-package))
> -- 
> 2.31.1
> 
It's an open question:
until now armadillo was always built with blas and lapack support provided by
clapack. To avoid breaking current behaviour (lapack support) why not
considering selecting lapack package unconditionaly and let user choise for
blas support? I know the main issue is the dependency to fortran...

Thanks
Gwen