package/fftw: add ARM optimisations

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
[based on a patch by Guillaume]
Cc: guillaume william brs <guillaume.bressaix@gmail.com>
Cc: Gwenhael Goavec-Merou <gwenhael.goavec-merou@trabucayre.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/fftw/Config.in

@@ -18,6 +18,9 @@ config BR2_PACKAGE_FFTW_USE_SSE
 config BR2_PACKAGE_FFTW_USE_SSE2
 	bool
 
+config BR2_PACKAGE_FFTW_USE_NEON
+	bool
+
 choice
 	prompt "fftw precision"
 	default BR2_PACKAGE_FFTW_PRECISION_DOUBLE
@@ -28,6 +31,7 @@ config BR2_PACKAGE_FFTW_PRECISION_SINGLE
 	bool "single"
 	select BR2_PACKAGE_FFTW_USE_SSE if BR2_X86_CPU_HAS_SSE
 	select BR2_PACKAGE_FFTW_USE_SSE2 if BR2_X86_CPU_HAS_SSE2
+	select BR2_PACKAGE_FFTW_USE_NEON if BR2_ARM_CPU_HAS_NEON && !BR2_ARM_SOFT_FLOAT
 	help
 	  Compile fftw in single precision, i.e. use 'float' for floating
 	  point type.

package/fftw/fftw.mk

@@ -23,6 +23,10 @@ endif
 FFTW_CONF_OPTS += $(if $(BR2_PACKAGE_FFTW_USE_SSE),--enable,--disable)-sse
 FFTW_CONF_OPTS += $(if $(BR2_PACKAGE_FFTW_USE_SSE2),--enable,--disable)-sse2
 
+# ARM optimisations
+FFTW_CONF_OPTS += $(if $(BR2_PACKAGE_FFTW_USE_NEON),--enable,--disable)-neon
+FFTW_CFLAGS += $(if $(BR2_PACKAGE_FFTW_USE_NEON),-mfpu=neon)
+
 FFTW_CONF_OPTS += CFLAGS="$(FFTW_CFLAGS)"
 
 $(eval $(autotools-package))