From: Segher Boessenkool <segher@kernel.crashing.org>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
clang-built-linux@googlegroups.com,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 2/2] powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto
Date: Thu, 26 Aug 2021 09:12:54 -0500 [thread overview]
Message-ID: <20210826141254.GB1583@gate.crashing.org> (raw)
In-Reply-To: <87h7fcc2m4.fsf@mpe.ellerman.id.au>
On Thu, Aug 26, 2021 at 01:21:39PM +1000, Michael Ellerman wrote:
> So there seems to be some misunderstanding with clang, it doesn't like
> us passing an expression to the inline asm.
>
> AFAIK it is legal to pass expressions as inputs to inline asm, ie. it
> doesn't have to just be a variable name.
It certainly is. That is the whole point of inline asm! This way, all
of the C code "around" the asm can be optimised.
> This patch seems to fix it. Not sure if that's just papering over it though.
It is, and it makes less optimised code (also on GCC), as Christophe
points out.
Segher
next prev parent reply other threads:[~2021-08-26 14:19 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 16:38 [PATCH v2 1/2] powerpc/bug: Remove specific powerpc BUG_ON() and WARN_ON() on PPC32 Christophe Leroy
2021-04-13 16:38 ` [PATCH v2 2/2] powerpc/bug: Provide better flexibility to WARN_ON/__WARN_FLAGS() with asm goto Christophe Leroy
2021-08-13 6:19 ` Nicholas Piggin
2021-08-15 3:49 ` Michael Ellerman
2021-08-25 21:25 ` Nathan Chancellor
2021-08-26 3:21 ` Michael Ellerman
2021-08-26 6:37 ` Christophe Leroy
2021-08-26 13:47 ` Segher Boessenkool
2021-08-26 14:45 ` Michael Ellerman
2021-08-26 14:53 ` Christophe Leroy
2021-08-26 14:12 ` Segher Boessenkool [this message]
2021-08-26 18:54 ` Nathan Chancellor
2021-08-26 23:55 ` Nathan Chancellor
2021-08-27 7:53 ` Michael Ellerman
2021-08-13 6:08 ` [PATCH v2 1/2] powerpc/bug: Remove specific powerpc BUG_ON() and WARN_ON() on PPC32 Nicholas Piggin
2021-08-18 15:06 ` Segher Boessenkool
2021-08-26 3:26 ` Nicholas Piggin
2021-08-26 12:49 ` Segher Boessenkool
2021-08-26 13:57 ` Nicholas Piggin
2021-08-26 14:37 ` Segher Boessenkool
2021-08-26 15:04 ` Nicholas Piggin
2021-08-26 15:30 ` Segher Boessenkool
2021-08-27 1:28 ` Nicholas Piggin
2021-08-18 13:38 ` Michael Ellerman
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