linux-kernel - Re: [PATCH v2 3/4] LoongArch: Stop using undocumented assembler options

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Message-ID: <615b5bc79c9e48409361bde1af9374cacb06ec9c.camel@xry111.site>
Date:   Thu, 28 Jul 2022 21:10:34 +0800
From:   Xi Ruoyao <xry111@...111.site>
To:     Huacai Chen <chenhuacai@...nel.org>
Cc:     loongarch@...ts.linux.dev, LKML <linux-kernel@...r.kernel.org>,
        WANG Xuerui <kernel@...0n.name>,
        Youling Tang <tangyouling@...ngson.cn>,
        Jinyang He <hejinyang@...ngson.cn>
Subject: Re: [PATCH v2 3/4] LoongArch: Stop using undocumented assembler
 options

On Thu, 2022-07-28 at 20:25 +0800, Huacai Chen wrote:
> Hi, Ruoyao,
> 
> On Thu, Jul 28, 2022 at 8:03 PM Xi Ruoyao <xry111@...111.site> wrote:
> > 
> > Now we can handle GOT and GOT-based relocations properly, remove the
> > undocumented `-Wa,-mla-{global,local}-with-{pcrel,abs}` assembler
> > hacks.
> I think "-Wa,-mla-{global,local}-with-{pcrel,abs}" may be regular
> options rather than "hacks". If I'm right, the title and commit
> message should be updated. And we can send patches to binutils to make
> them "documented".

How about changing the message to:

   GCC 13 no longer generates la.global and la.local in assembly, but
   produces explicit PC-relative relocations to local symbols and GOT
   entries for global symbols instead.  As the result, -Wa,-mla-* are no
   longer sufficient to control the code generation for symbol address
   loading.  As now we can handle GOT and GOT-based relocations
   properly, remove those options to use GOT for global symbol address
   consistently.