arm64 NEON option in cmake

[fllay]

I try to build srsran with raspberry pi 5 with NEON support. From cmake output, I didn't see that it checks for NEON

pi@pi5:~/src/srsRAN_Project/build$ cmake ..
-- The C compiler identification is GNU 13.2.0
-- The CXX compiler identification is GNU 13.2.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Build type not specified: defaulting to Release.
-- Performing Test HAS_MAYBE_UNINITIALIZED
-- Performing Test HAS_MAYBE_UNINITIALIZED - Success
-- Performing Test HAS_STRINGOP_OVERFLOW
-- Performing Test HAS_STRINGOP_OVERFLOW - Success
-- Performing Test HAVE_NON_VIRTUAL_DTOR
-- Performing Test HAVE_NON_VIRTUAL_DTOR - Success
-- Performing Test HAVE_SUGGEST_OVERRIDE
-- Performing Test HAVE_SUGGEST_OVERRIDE - Success
-- Performing Test HAVE_SHADOW
-- Performing Test HAVE_SHADOW - Success
-- Assertion level set to NORMAL
-- Could NOT find libdw (missing: LIBDW_LIBRARY LIBDW_INCLUDE_DIR) 
-- Could NOT find libbfd (missing: LIBBFD_LIBRARY LIBBFD_INCLUDE_DIR) 
-- Could NOT find libdwarf (missing: LIBDWARF_LIBRARY LIBDWARF_INCLUDE_DIR LIBELF_LIBRARY LIBELF_INCLUDE_DIR) 
-- Found Backward: /home/pi/src/srsRAN_Project/cmake/modules  
-- Backward-cpp found, but external libraries are missing.
-- Found PkgConfig: /usr/bin/pkg-config (found version "1.8.1") 
-- Checking for module 'mbedtls'
--   Found mbedtls, version 2.28.8
-- MBEDTLS LIBRARIES: /usr/lib/aarch64-linux-gnu/libmbedcrypto.so
-- MBEDTLS STATIC LIBRARIES: /usr/lib/aarch64-linux-gnu/libmbedcrypto.a
-- MBEDTLS INCLUDE DIRS: /usr/include
-- Found MbedTLS: /usr/lib/aarch64-linux-gnu/libmbedcrypto.so  
-- Checking for module 'fftw3f >= 3.0'
--   Found fftw3f, version 3.3.10
-- FFTW3F LIBRARIES: /usr/lib/aarch64-linux-gnu/libfftw3f.so
-- FFTW3F STATIC LIBRARIES: /usr/lib/aarch64-linux-gnu/libfftw3f.a
-- FFTW3F INCLUDE DIRS: /usr/include
-- Found FFTW3F: /usr/lib/aarch64-linux-gnu/libfftw3f.so  
-- Found GTest: /usr/lib/aarch64-linux-gnu/cmake/GTest/GTestConfig.cmake (found version "1.14.0")  
-- Found Threads: TRUE  
-- UHD LIBRARIES /usr/lib/aarch64-linux-gnu/libuhd.so
-- UHD INCLUDE DIRS /usr/include
-- Found UHD: /usr/lib/aarch64-linux-gnu/libuhd.so  
-- Checking for module 'yaml-cpp'
--   Found yaml-cpp, version 0.8.0
-- YAMLCPP LIBRARIES: /usr/lib/aarch64-linux-gnu/libyaml-cpp.so
-- YAMLCPP INCLUDE DIRS: /usr/include
-- Found YAMLCPP: /usr/lib/aarch64-linux-gnu/libyaml-cpp.so  
-- Detected aarch64 processor
-- Performing Test HAVE_SSE
-- Performing Test HAVE_SSE - Failed
-- Performing Test HAVE_AVX
-- Performing Test HAVE_AVX - Failed
-- Performing Test HAVE_AVX2
-- Performing Test HAVE_AVX2 - Failed
-- Performing Test HAVE_FMA
-- Performing Test HAVE_FMA - Failed
-- Performing Test HAVE_AVX512
-- Performing Test HAVE_AVX512 - Failed
-- Performing Test HAVE_MARCH
-- Performing Test HAVE_MARCH - Failed
-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
-- Checking for module 'sctp'
--   Package 'sctp', required by 'virtual:world', not found
-- SCTP LIBRARIES: /usr/lib/aarch64-linux-gnu/libsctp.so
-- SCTP INCLUDE DIRS: /usr/include
-- Found SCTP: /usr/lib/aarch64-linux-gnu/libsctp.so  
-- FFT_LIBRARIES: /usr/lib/aarch64-linux-gnu/libfftw3f.so
-- Building srsRAN version 24.04.0
-- Configuring done (4.6s)
-- Generating done (1.6s)
-- Build files have been written to: /home/pi/src/srsRAN_Project/build

Do I need a special flag to enable NEON? BTW, I can use gnb with raspberry pi 5 with SISO and 20MHz BW without any issue.

[dvdgrgrtt]

Hi @fllay,

in principle you don't need any flag, NEON is active by default in ARM. If you want to double check, look into build/lib/phy/upper/channel_coding/ldpc/CMakeFiles/srsran_ldpc.dir after compiling and verify that you have the neon object files like, e.g., ldpc_decoder_neon.cpp.o

[fllay]

thank you. I have checked and it seems to be ok.

-rw-rw-r-- 1 pi pi  35952 Jul  5 15:39 ldpc_decoder_neon.cpp.o
-rw-rw-r-- 1 pi pi  16437 Jul  5 15:39 ldpc_decoder_neon.cpp.o.d
-rw-rw-r-- 1 pi pi  28648 Jul  5 15:39 ldpc_encoder_generic.cpp.o
-rw-rw-r-- 1 pi pi  15974 Jul  5 15:39 ldpc_encoder_generic.cpp.o.d
-rw-rw-r-- 1 pi pi  18472 Jul  5 15:39 ldpc_encoder_impl.cpp.o
-rw-rw-r-- 1 pi pi  15660 Jul  5 15:39 ldpc_encoder_impl.cpp.o.d
-rw-rw-r-- 1 pi pi 411440 Jul  5 15:39 ldpc_encoder_neon.cpp.o
-rw-rw-r-- 1 pi pi  16437 Jul  5 15:39 ldpc_encoder_neon.cpp.o.d
-rw-rw-r-- 1 pi pi  11144 Jul  5 15:39 ldpc_graph_impl.cpp.o