linux-kernel - Re: [PATCH v2] x86, bitops, variable_test_bit should return 1 not -1 on a match

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Message-ID: <20151008085132.GB4729@gmail.com>
Date:	Thu, 8 Oct 2015 10:51:33 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Prarit Bhargava <prarit@...hat.com>
Cc:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org
Subject: Re: [PATCH v2] x86, bitops, variable_test_bit should return 1 not -1
 on a match


* Prarit Bhargava <prarit@...hat.com> wrote:

> re-ping on this.  Just making sure this wasn't dropped on the floor.

So I didn't apply it back when I saw your patch because I didn't see where you 
addressed/analyzed the second paragraph of hpa's review:

  "The downside with set is that it only sets a single byte, the upside is that it 
   always outputs 0 or 1, and apparently if the output variable is your bool gcc 
   can use that for optimization."

That's a valid concern and should be addressed.

Thanks,

	Ingo
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