lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 23 Dec 2016 21:43:46 +0100
From:   Rasmus Villemoes <>
To:     Matthew Wilcox <>
Cc:     Yury Norov <>,
        George Spelvin <>,
        Akinobu Mita <>,
        Thomas Gleixner <>,
        Andrew Morton <>,,
        Matthew Wilcox <>
Subject: Re: [PATCH] find_bit: Micro-optimise find_next_*_bit

On Fri, Dec 23 2016, Matthew Wilcox <> wrote:

> From: Matthew Wilcox <>
> First, the first half of the test: (!nbits || start >= nbits) is
> trivially a subset of the second half, since nbits and start are both unsigned.

Yeah, I filed that as a missed optimization bug with gcc a year ago, but
it seems that even 6.3 still does two tests - clang 3.6 is a bit
smarter. Anyway,

Acked-by: Rasmus Villemoes <>

Powered by blists - more mailing lists