Re: [dpdk-dev] [PATCH 2/2] net/igc: fix gcc build for optimization level 0

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

On Fri, Nov 27, 2020 at 10:02 AM David Marchand
<david.marchand@redhat.com> wrote:
>
> On Fri, Nov 27, 2020 at 9:10 AM Ruifeng Wang <ruifeng.wang@arm.com> wrote:
> >
> > Gcc build with '-O0' failed for:
> >  ../drivers/net/igc/base/igc_api.c
> >  Assembler messages:
> > 29: Error: selected processor does not support `casp x0,x1,x2,x3,[x4]'
> > 82: Error: selected processor does not support `caspa x0,x1,x2,x3,[x4]'
> > 135: Error: selected processor does not support `caspl x0,x1,x2,x3,[x4]'
> > 188: Error: selected processor does not support `caspal x0,x1,x2,x3,[x4]'
> >
> > This is due to c_args not been passed to meson.
> >
> > Fixes: 8cb7c57d9b3c ("net/igc: support device initialization")
> > Cc: alvinx.zhang@intel.com
> >
> > Reported-by: Feifei Wang <feifei.wang2@arm.com>
> > Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
>
> I did not get to reproduce it yet (get an error on first patch...).
>
> The patch looks fine but I fear some compilation problems since a lot
> of base drivers filter cflags.
> Still waiting for CI results...
>
> Bruce,Ferruh,
> Wdyt?

Comparing before/after patch on x86, gcc, static build, the only difference is:
 -march=native -DALLOW_EXPERIMENTAL_API -DALLOW_INTERNAL_API
-Wno-format-truncation

Which corresponds to drivers/meson.build:

default_cflags = machine_args
default_cflags += ['-DALLOW_EXPERIMENTAL_API']
default_cflags += ['-DALLOW_INTERNAL_API']

if cc.has_argument('-Wno-format-truncation')
        default_cflags += '-Wno-format-truncation'
endif

So little risk wrt warning flags.
Still I'd like to hear from Intel, thanks.


-- 
David Marchand