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Date:   Wed, 19 Jul 2023 06:33:53 +0200
From:   Willy Tarreau <w@1wt.eu>
To:     Zhangjin Wu <falcon@tinylab.org>
Cc:     thomas@t-8ch.de, arnd@arndb.de, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org
Subject: Re: [PATCH v1 3/8] selftests/nolibc: select_null: fix up for big
 endian powerpc64
Message-ID: <20230719043353.GC5331@1wt.eu>
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 <20230718235637.347701-1-falcon@tinylab.org>
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Hi Zhangjin,

On Wed, Jul 19, 2023 at 07:56:37AM +0800, Zhangjin Wu wrote:
> It made me recalled I have at last disabled (not enabled for tinyconfig) the following options:
> 
>     CONFIG_ALTIVEC
>     CONFIG_VSX --> This option enables kernel support for the Vector Scaler extensions
> 
> Or we can disable the vsx instructions explicitly:
> 
>     -mno-vsx
> 
> Both of them work well, but I prefer -mno-vsx for to get a faster build, what about you?
> 
>     +CFLAGS_powerpc64 = -m64 -mbig-endian -Wl,-EB,-melf64ppc -mno-vsx
>     +CFLAGS_powerpc64le = -m64 -mlittle-endian -Wl,-EL,-melf64ppc -mno-vsx
> 
> So, this patch itself is wrong, let's drop it from the next revision.

Better explicitly disable it in the CFLAGS (2nd option) if we want to
make sure we don't want to rely on this, at least for portability
purposes.

Willy