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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri, 26 May 2023 10:40:39 -0700
Message-ID: <CAHk-=wh16fVwO2yZ4Fx0kyRHsNDhGddzNxfQQz2+x08=CPvk_Q@mail.gmail.com>
Subject: Re: x86 copy performance regression
To:     Eric Dumazet <edumazet@google.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>
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On Fri, May 26, 2023 at 10:25=E2=80=AFAM Eric Dumazet <edumazet@google.com>=
 wrote:
>
> arch/x86/lib/copy_user_64.S:34:2: error: invalid instruction mnemonic
> 'alternative'

Ok, that's just odd. For me, assembler mnemonics - very much including
macros - are case-insensitive.

It's actually documented that way, with the example given is for a
macro that is declared as "sum" and then used as "SUM":

   https://sourceware.org/binutils/docs/as/Macro.html

And if you want to use macros as pseudo-instructions, that's what you
want, since typically assembler instructions are not case sensitive.

But yeah, your build environment is clearly different, and yes, we
declare the macro with all caps, and other places use it that way too.

Clang?

              Linus