From: Roland McGrath <roland@hack.frob.com>
To: Richard Henderson <rth@twiddle.net>
Cc: libc-ports@sourceware.org
Subject: Re: [PATCH roland/arm-atomic-warn] Fiddle ARM atomic.h to avoid -Wvolatile-register-var warnings.
Date: Wed, 08 Aug 2012 22:13:00 -0000 [thread overview]
Message-ID: <20120808221302.6648D2C0ED@topped-with-meat.com> (raw)
In-Reply-To: Richard Henderson's message of Wednesday, 8 August 2012 15:02:12 -0700 <5022E1E4.7040801@twiddle.net>
> Is it really worth working so hard to avoid the gcc builtins?
> Yes, gcc before 4.7 doesn't have __atomic to avoid the extra
> barriers, but at least 4.7 and later will.
That file uses them #ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4.
I was just killing a warning without worrying about why the code
path was being used.
> May I ask what gcc version you're targeting, anyway?
I'm using today's trunk, cross --target=arm-linux-gnueabi and no other
special options. I don't know why __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 is
not defined. Probably it would be with appropriate -march= settings.
Thanks,
Roland
prev parent reply other threads:[~2012-08-08 22:13 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-08 20:44 Roland McGrath
2012-08-08 20:52 ` Joseph S. Myers
2012-08-08 22:02 ` Richard Henderson
2012-08-08 22:13 ` Roland McGrath [this message]
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