From mboxrd@z Thu Jan  1 00:00:00 1970
From: pebolle@tiscali.nl (Paul Bolle)
Date: Thu, 08 May 2014 09:12:51 +0200
Subject: [PATCH v2] NVMe: silence GCC warning on 32 bit
In-Reply-To: <1395675399.6440.14.camel@x220>
References: <1392714172-2712-1-git-send-email-geert@linux-m68k.org>
 <1392934261.15264.22.camel@x220> <alpine.LRH.2.03.1402210921010.4656@AMR>
 <1393925767.3038.23.camel@x220> <20140324131104.GC5777@linux.intel.com>
 <20140324133154.GD5777@linux.intel.com> <1395675399.6440.14.camel@x220>
Message-ID: <1399533171.19191.8.camel@x41>

Matthew,

Paul Bolle schreef op ma 24-03-2014 om 16:36 [+0100]:
> On Mon, 2014-03-24@09:31 -0400, Matthew Wilcox wrote:
> > I should try things myself before opening my big mouth.  Weird.  Using
> > gcc-4.8, I see the same thing.  Guess I should just apply the patch,
> > though it feels wrong to be initialising an entire struct just to silence
> > a bogus compiler warning :-(
> 
> I noticed this difference on a 32 bit x86 machine and a 64 bit x86
> machine that are both running Fedora 20. They both should be at
> gcc-4.8.2 for quite some time now (if I grepped the yum log correctly).
> 
> Anyhow, the warning on 32 bit is rather noisy, so I wanted it gone. But
> my comments should make clear I'm not really happy with this patch. 
> 
> And as this is now unlikely to be in time for v3.14, we might decide to
> dig deeper. It won't be the first time that a rather small change (say,
> converting a variable from signed to unsigned) turns out be enough to
> make GCC understand the flow of the code.

This noisy warning is still seen when compiling v3.15-rc4 for x86 (32
bit, that is). Assuming this patch is not queued anywhere: is the
unsophisticated approach of my v2 acceptable or would you like me to try
and find the cause of this warning?


Paul Bolle