Re: [PATCH] elf: Remove -fno-tree-loop-distribute-patterns usage on dl-support

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Aug 9, 2022 at 12:32 PM Adhemerval Zanella Netto
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 09/08/22 16:06, H.J. Lu wrote:
> > On Tue, Aug 9, 2022 at 11:48 AM Adhemerval Zanella Netto
> > <adhemerval.zanella@linaro.org> wrote:
> >>
> >>
> >>
> >> On 09/08/22 15:31, H.J. Lu wrote:
> >>> On Tue, Aug 9, 2022 at 5:11 AM Adhemerval Zanella Netto
> >>> <adhemerval.zanella@linaro.org> wrote:
> >>>>
> >>>>
> >>>>
> >>>> On 08/08/22 19:16, H.J. Lu wrote:
> >>>>
> >>>>>> --- a/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> >>>>>> +++ b/sysdeps/x86_64/multiarch/memset-evex-unaligned-erms.S
> >>>>>> @@ -44,4 +44,7 @@
> >>>>>>
> >>>>>>  # define USE_LESS_VEC_MASK_STORE       1
> >>>>>>  # include "memset-vec-unaligned-erms.S"
> >>>>>> +# if !defined NO_MULTIARCH && MINIMUM_X86_ISA_LEVEL >= 4
> >>>>>> +strong_alias (__memset_evex_unaligned, __memset_generic)
> >>>>>> +# endif
> >>>>>>  #endif
> >>>>>
> >>>>> This will define 2 __memset_generic for -march=x86-64-v4.
> >>>>
> >>>> Are you sure? Check with a x86_64 build with -march=x86-64-v4 I am seeing:
> >>>>
> >>>> $ readelf -Ws string/memset*.os | grep -w __memset_generic | wc -l
> >>>> 1
> >>>>
> >>>> And it is indeed provided only by string/memset-evex-unaligned-erms.os.
> >>>
> >>> You are right.  Since dl-symbol-hacks.h defines memset to an alias,
> >>> should it be moved to sysdes/generic and each arch can provide a
> >>> suitable alias?
> >>
> >> The dl-symbol-hacks.h is meant to be used solely by loader code (that's
> >> why I have added to elf/), but I don't have a strong preference.
> >
> > The default should be no alias.  Only IFUNC targets need to define a
> > proper alias.
>
> Alright, although I added the alias on all targets to avoid adding another
> hook to specify whether memset is implemented by IFUNC (to enable the
> symbol redirection instead of use the default symbol name).  I am not sure
> if making arch-specific will simplify the required code here.

But your patch adds alias to all targets.

-- 
H.J.