kumquat-buildroot/package/openblas/openblas.mk
Thomas De Schampheleire 6f29cdeee4 package/openblas: allow disabling multithreading
Buildroot would automatically enable multithreading in OpenBLAS if the
architecture supports it. However, one may want to avoid OpenBLAS creating
threads itself and configure single-threaded operation. To accommodate this
use case, add a config option for multithreading.

When multithreading is disabled but OpenBLAS functions are called in the
same application by multiple threads, then locking is mandatory. The
USE_LOCKING flag was added in version 0.3.7 with following release note:

    a new option USE_LOCKING was added to ensure thread safety when OpenBLAS
    itself is built without multithreading but will be called from multiple
    threads.

However, if one knows that OpenBLAS will only be called from single-threaded
applications, then passing USE_LOCKING is not necessary, so make it a config
option too.

When multithreading is enabled, locking is implicitly enabled inside
openblas, so only provide the locking option when multithreading is
disabled.

Signed-off-by: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
2021-02-16 23:10:57 +01:00

80 lines
2.3 KiB
Makefile

################################################################################
#
# openblas
#
################################################################################
OPENBLAS_VERSION = 0.3.9
OPENBLAS_SITE = $(call github,xianyi,OpenBLAS,v$(OPENBLAS_VERSION))
OPENBLAS_LICENSE = BSD-3-Clause
OPENBLAS_LICENSE_FILES = LICENSE
OPENBLAS_INSTALL_STAGING = YES
# Initialise OpenBLAS make options to $(TARGET_CONFIGURE_OPTS)
OPENBLAS_MAKE_OPTS = $(TARGET_CONFIGURE_OPTS)
# Enable cross-compiling
OPENBLAS_MAKE_OPTS += CROSS=1
# Set OpenBLAS target
OPENBLAS_MAKE_OPTS += TARGET=$(BR2_PACKAGE_OPENBLAS_TARGET)
# When Fortran is not available, only build the C version of BLAS
ifeq ($(BR2_TOOLCHAIN_HAS_FORTRAN),)
OPENBLAS_MAKE_OPTS += ONLY_CBLAS=1
endif
# Enable/Disable multi-threading (not for static-only since it uses dlfcn.h)
ifeq ($(BR2_PACKAGE_OPENBLAS_USE_THREAD),y)
OPENBLAS_MAKE_OPTS += USE_THREAD=1
else
OPENBLAS_MAKE_OPTS += USE_THREAD=0
endif
ifeq ($(BR2_PACKAGE_OPENBLAS_USE_LOCKING),y)
OPENBLAS_MAKE_OPTS += USE_LOCKING=1
else
# not passing USE_LOCKING=0 as this could be confusing: its effect is implicit
# in case of USE_THREAD=1.
endif
# We don't know if OpenMP is available or not, so disable
OPENBLAS_MAKE_OPTS += USE_OPENMP=0
# Static-only/Shared-only toggle
ifeq ($(BR2_STATIC_LIBS),y)
OPENBLAS_MAKE_OPTS += NO_SHARED=1
else ifeq ($(BR2_SHARED_LIBS),y)
OPENBLAS_MAKE_OPTS += NO_STATIC=1
endif
# binutils version <= 2.23.2 has a bug
# (https://sourceware.org/bugzilla/show_bug.cgi?id=14887) where
# whitespaces in ARM register specifications such as [ r1, #12 ] or [
# r2 ] cause the assembler to reject the code. Since there are
# numerous instances of such cases in the code, we use sed rather than
# a patch. We simply replace [ foobar ] by [foobar] to work around the
# problem.
define OPENBLAS_FIXUP_ARM_ASSEMBLY
$(SED) 's%\[\s*%\[%;s%\s*\]%\]%' $(@D)/kernel/arm/*.S
endef
OPENBLAS_POST_PATCH_HOOKS += OPENBLAS_FIXUP_ARM_ASSEMBLY
define OPENBLAS_BUILD_CMDS
$(TARGET_MAKE_ENV) $(MAKE) $(OPENBLAS_MAKE_OPTS) \
-C $(@D)
endef
define OPENBLAS_INSTALL_STAGING_CMDS
$(TARGET_MAKE_ENV) $(MAKE) $(OPENBLAS_MAKE_OPTS) \
-C $(@D) install PREFIX=$(STAGING_DIR)/usr
endef
define OPENBLAS_INSTALL_TARGET_CMDS
$(TARGET_MAKE_ENV) $(MAKE) $(OPENBLAS_MAKE_OPTS) \
-C $(@D) install PREFIX=$(TARGET_DIR)/usr
endef
$(eval $(generic-package))