From: Richard Henderson <rth@twiddle.net>
To: Pranith Kumar <bobby.prani@gmail.com>,
"Emilio G. Cota" <cota@braap.org>,
"open list:All patches CC here" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH] util/cacheinfo: Fix warning generated by clang
Date: Sat, 1 Jul 2017 15:20:25 -0700 [thread overview]
Message-ID: <63517903-f0e7-59db-47e2-e12f595092cf@twiddle.net> (raw)
In-Reply-To: <20170630153946.11997-1-bobby.prani@gmail.com>
On 06/30/2017 08:39 AM, Pranith Kumar wrote:
> Clang generates the following warning on aarch64 host:
>
> CC util/cacheinfo.o
> /home/pranith/qemu/util/cacheinfo.c:121:48: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
> asm volatile("mrs\t%0, ctr_el0" : "=r"(ctr));
> ^
> /home/pranith/qemu/util/cacheinfo.c:121:28: note: use constraint modifier "w"
> asm volatile("mrs\t%0, ctr_el0" : "=r"(ctr));
> ^~
> %w0
That is an absolutely stupid warning. There's long precedent for the compiler
choosing the prefix for you based on the type of the argument.
>
> Constraint modifier 'w' is not (yet?) accepted by gcc. Fix this by increasing the ctr size.
Certainly it is -- since the beginning of time.
r~
next prev parent reply other threads:[~2017-07-01 22:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-30 15:39 [Qemu-devel] [PATCH] util/cacheinfo: Fix warning generated by clang Pranith Kumar
2017-06-30 21:15 ` Emilio G. Cota
2017-07-01 22:20 ` Richard Henderson [this message]
2017-07-01 22:30 ` Peter Maydell
2017-07-01 22:35 ` Richard Henderson
2017-07-01 22:44 ` Peter Maydell
2017-07-03 21:16 ` Richard Henderson
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