Re: [PATCH v2 0/5] loongarch: add relaxation support

[mengqinggang]

Is this  patch used to check if ld supports --no-relax option?

It need to pass -mno-relax option to as or gcc to disable binutils
generate relaxation relocations.

在 2023/6/13 上午10:37, Xiaotian Wu 写道:

> New patch is ready:
> https://github.com/loongarch64/grub/commits/dev-master
>
> I need your help to confirm that binutils-2.40 and binutils-dev code
> have the same behavior when using compile options, thanks.
>
> 在 2023-06-12星期一的 06:35 +0800，Xi Ruoyao via Grub-devel写道：
> > On Wed, 2023-06-07 at 15:34 +0800, Xiaotian Wu wrote:
> > > Because the binutils of the loongarch architecture adds relaxation
> > > support [1], the next version of binutils will not be able to build
> > > grub.
> > >
> > > So we added the R_LARCH_B16, R_LARCH_B21 and R_LARCH_RELAX
> > > relocations
> > > to enhance grub compatibility.
> > >         
> > Wouldn't it be easier to just pass -mno-relax to the toolchain when
> > we
> > build GRUB?  I don't think it makes too much sense to perform
> > relaxation
> > on a boot loader.  The boot loader is generally the coldest code
> > paths
> > in a system, so relaxing it won't give any real benefit (well, if you
> > reboot a system 100 times you may finally save one second), but
> > increases the maintenance burden.
> >
> > Consider a new relaxation pattern is added after we release GRUB
> > 2.12. 
> > Then if we simply pass -mno-relax, GRUB 2.12 will continue to work. 
> > But
> > if we try to "support" relaxation this way, every distro will have to
> > patch GRUB 2.12 when the toolchain is updated.
> >
> > > [1]:
> > > https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=56576f4a722b7398d35802ecf7d4185c27d6d69b
> > >
> > > v1->v2:
> > > - split patch
> > > - drop cast code
> > >
> > > Xiaotian Wu (5):
> > >   Use the correct format specifier for formatted output
> > >   loongarch: Optimize code using pc variable
> > >   loongarch: Rename function names
> > >   loongarch: Add ELF relocation types documentation and comments
> > >   loongarch: Add relaxation support
> > >
> > >  grub-core/kern/arm64/dl_helper.c       |  4 +-
> > >  grub-core/kern/loongarch64/dl.c        | 21 +++++++-
> > >  grub-core/kern/loongarch64/dl_helper.c | 72
> > > ++++++++++++++++++++++++-
> > > -
> > >  include/grub/elf.h                     |  3 ++
> > >  include/grub/loongarch64/reloc.h       |  6 ++-
> > >  util/grub-mkimagexx.c                  | 28 ++++++++--
> > >  util/grub-module-verifier.c            |  3 ++
> > >  7 files changed, 124 insertions(+), 13 deletions(-)
> > >
> > >         
> >       
>