package/fftw: add x86 optimisations

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

package/fftw/Config.in

@@ -12,6 +12,12 @@ config BR2_PACKAGE_FFTW
 
 if BR2_PACKAGE_FFTW
 
+config BR2_PACKAGE_FFTW_USE_SSE
+	bool
+
+config BR2_PACKAGE_FFTW_USE_SSE2
+	bool
+
 choice
 	prompt "fftw precision"
 	default BR2_PACKAGE_FFTW_PRECISION_DOUBLE
@@ -20,12 +26,15 @@ choice
 
 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
 	help
 	  Compile fftw in single precision, i.e. use 'float' for floating
 	  point type.
 
 config BR2_PACKAGE_FFTW_PRECISION_DOUBLE
 	bool "double"
+	select BR2_PACKAGE_FFTW_USE_SSE2 if BR2_X86_CPU_HAS_SSE2
 	help
 	  Compile fftw in double precision (the default), i.e. use 'double'
 	  for floating point type.

package/fftw/fftw.mk

@@ -19,6 +19,10 @@ ifeq ($(BR2_PACKAGE_FFTW_FAST),y)
 FFTW_CFLAGS += -Ofast
 endif
 
+# x86 optimisations
+FFTW_CONF_OPTS += $(if $(BR2_PACKAGE_FFTW_USE_SSE),--enable,--disable)-sse
+FFTW_CONF_OPTS += $(if $(BR2_PACKAGE_FFTW_USE_SSE2),--enable,--disable)-sse2
+
 FFTW_CONF_OPTS += CFLAGS="$(FFTW_CFLAGS)"
 
 $(eval $(autotools-package))