> -----Original Message-----
> From: fengchengwen <fengcheng...@huawei.com>
> Sent: Monday, June 28, 2021 11:56 AM
> To: Ruifeng Wang <ruifeng.w...@arm.com>; tho...@monjalon.net;
> ferruh.yi...@intel.com
> Cc: dev@dpdk.org; bruce.richard...@intel.com;
> vladimir.medved...@intel.com; vikto...@rehivetech.com;
> jer...@marvell.com; Honnappa Nagarahalli
> <honnappa.nagaraha...@arm.com>; jerinjac...@gmail.com;
> juraj.lin...@pantheon.tech; nd <n...@arm.com>
> Subject: Re: [PATCH 2/2] net/hns3: fix SVE code compile error with gcc8.3
>
> On 2021/6/28 11:33, Ruifeng Wang wrote:
> >> -----Original Message-----
> >> From: Chengwen Feng <fengcheng...@huawei.com>
> >> Sent: Monday, June 28, 2021 10:58 AM
> >> To: tho...@monjalon.net; ferruh.yi...@intel.com; Ruifeng Wang
> >> <ruifeng.w...@arm.com>
> >> Cc: dev@dpdk.org; bruce.richard...@intel.com;
> >> vladimir.medved...@intel.com; vikto...@rehivetech.com;
> >> jer...@marvell.com; Honnappa Nagarahalli
> >> <honnappa.nagaraha...@arm.com>; jerinjac...@gmail.com;
> >> juraj.lin...@pantheon.tech
> >> Subject: [PATCH 2/2] net/hns3: fix SVE code compile error with gcc8.3
> >>
> >> If the target machine has SVE feature (e.g. '-march=armv8.2-a+sve'),
> >> and compiler are gcc8.3, it will compile error, the error is
> >> arm_sve.h no such file or directory.
> >>
> >> The solution:
> >> a. If RTE_HAS_SVE_ACLE defined (it means the minimum instruction set
> >> support SVE ACLE) then compiles it.
> >> b. Else if the compiler support SVE ACLE then compiles it.
> >> c. Otherwise don't compile it.
> >>
> >> Fixes: 8c25b02b082a ("net/hns3: fix enabling SVE Rx/Tx")
> >> Fixes: 952ebacce4f2 ("net/hns3: support SVE Rx")
> >> Cc: sta...@dpdk.org
> >>
> >> Signed-off-by: Chengwen Feng <fengcheng...@huawei.com>
> >> Acked-by: Ruifeng Wang <ruifeng.w...@arm.com>
> >> ---
> >> drivers/net/hns3/hns3_rxtx.c | 2 +- drivers/net/hns3/meson.build |
> >> 20 +++++++++++++++++++-
> >> 2 files changed, 20 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/net/hns3/hns3_rxtx.c
> >> b/drivers/net/hns3/hns3_rxtx.c index cb9eccf..a86e105 100644
> >> --- a/drivers/net/hns3/hns3_rxtx.c
> >> +++ b/drivers/net/hns3/hns3_rxtx.c
> >> @@ -2811,7 +2811,7 @@ hns3_get_default_vec_support(void)
> >> static bool
> >> hns3_get_sve_support(void)
> >> {
> >> -#if defined(RTE_ARCH_ARM64) && defined(__ARM_FEATURE_SVE)
> >> +#if defined(RTE_HAS_SVE_ACLE)
> >> if (rte_vect_get_max_simd_bitwidth() < RTE_VECT_SIMD_256)
> >> return false;
> >> if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SVE))
> >> diff --git a/drivers/net/hns3/meson.build
> >> b/drivers/net/hns3/meson.build index 53c7df7..a99e0db 100644
> >> --- a/drivers/net/hns3/meson.build
> >> +++ b/drivers/net/hns3/meson.build
> >> @@ -35,7 +35,25 @@ deps += ['hash']
> >>
> >> if arch_subdir == 'arm' and dpdk_conf.get('RTE_ARCH_64')
> >> sources += files('hns3_rxtx_vec.c')
> >> - if cc.get_define('__ARM_FEATURE_SVE', args: machine_args) != ''
> >> +
> >> + # compile SVE when:
> >> + # a. support SVE in minimum instruction set baseline
> >> + # b. it's not minimum instruction set, but compiler support
> >> + if dpdk_conf.has('RTE_HAS_SVE_ACLE')
> >> sources += files('hns3_rxtx_vec_sve.c')
> >> + elif cc.has_argument('-march=armv8.2-a+sve') and
> >> cc.check_header('arm_sve.h')
> >> + cflags += ['-DRTE_HAS_SVE_ACLE=1']
> >> + sve_cflags = []
> > Global cflags will be changed here. I think it is not very good as build of
> other parts could be without SVE support.
> > How about " sve_cflags = ['-DRTE_HAS_SVE_ACLE=1']" and drop changes to
> cflags?
> > In this way, the additional flag will be limited to hns3_sve_lib.
>
> This will not change global cflags: the cflags was independent from other
> drives [implemented in drivers/meson.build] And I also check the
> 'build.ninja' and found the RTE_HAS_SVE_ACLE only defined with hns3 driver
> source file.
> PS: hns3_rxtx.c also refer the marco 'RTE_HAS_SVE_ACLE'.
>
Thanks for the explanation. I see cflags is restored for each driver.
Looks good to me. My tag was already added.
> >
> >> + foreach flag: cflags
> >> + if not (flag.startswith('-march=') or
> >> + flag.startswith('-mcpu=') or
> >> flag.startswith('-mtune='))
> >> + sve_cflags += flag
> >> + endif
> >> + endforeach
> >> + hns3_sve_lib = static_library('hns3_sve_lib',
> >> + 'hns3_rxtx_vec_sve.c',
> >> + dependencies: [static_rte_ethdev],
> >> + include_directories: includes,
> >> + c_args: [sve_cflags, '-march=armv8.2-a+sve'])
> >> + objs += hns3_sve_lib.extract_objects('hns3_rxtx_vec_sve.c')
> >> endif
> >> endif
> >> --
> >> 2.8.1
> >
> >
> > .
> >
