Re: [dpdk-dev] [PATCH v5 2/2] net/hns3: refactor SVE code compile method

[David Marchand <david.marchand@redhat.com>]

On Wed, May 19, 2021 at 2:17 PM fengchengwen <fengchengwen@huawei.com> wrote:
> We also found compile error with gcc8.3 with arm64_kunpeng930_linux_gcc (-march=-march=armv8.2-a+crypto+sve):
>   In file included from ../dpdk-next-net/lib/eal/common/eal_common_options.c:38:
>   ../dpdk-next-net/lib/eal/arm/include/rte_vect.h:13:10: fatal error: arm_sve.h: No such file or directory
>    #include <arm_sve.h>
>           ^~~~~~~~~~~
>   compilation terminated.
>   [126/2250] Compiling C object lib/librte_net.a.p/net_rte_net_crc.c.o
>
> the corresponding code:
>   #ifdef __ARM_FEATURE_SVE
>   #include <arm_sve.h>
>   #endif
>
> this is because gcc8.3 defined __ARM_FEATURE_SVE but it can't compile ACLE SVE code.

Afaiu, gcc 8.3 does not define __ARM_FEATURE_SVE:

$ aarch64-linux-gnu-gcc --version
aarch64-linux-gnu-gcc (GNU Toolchain for the A-profile Architecture
8.3-2019.03 (arm-rel-8.36)) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.



$ aarch64-linux-gnu-gcc - -pipe -E -P -D_FILE_OFFSET_BITS=64 -P -O0
-march=armv8-a+crc <<EOF
>         #ifndef __ARM_FEATURE_SVE
>         # define __ARM_FEATURE_SVE
>         #endif
>         "MESON_GET_DEFINE_DELIMITER"
> __ARM_FEATURE_SVE
> EOF
        "MESON_GET_DEFINE_DELIMITER"


-- 
David Marchand