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  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, 1 Mar 2019 12:26:59 -0800
From:   Andrew Morton <>
To:     Jani Nikula <>
        Chris Wilson <>
Subject: Re: [PATCH] log2: make is_power_of_2() integer constant expression
 when possible

On Fri,  1 Mar 2019 14:52:07 +0200 Jani Nikula <> wrote:

> While is_power_of_2() is an inline function and likely gets optimized
> for compile time constant arguments, it still doesn't produce an integer
> constant expression that could be used in, say, static data
> initialization or case labels.

hm, what code wants to do these things?

> Make is_power_of_2() an integer constant expression when possible,
> otherwise using the inline function to avoid multiple evaluation of the
> parameter.

Spose so.  But I fear that some gcc versions will get it right and
others will mess it up.  While this patch is under test I think it
would be best to also have at least one or two callsites which actually
use the compile-time evaluation feature.  Possible?

Powered by blists - more mailing lists