lists.openwall.net   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:	Thu, 31 Oct 2013 13:03:30 +0100
From:	Levente Kurusa <levex@...ux.com>
To:	Richard Weinberger <richard.weinberger@...il.com>,
	韩磊 <bonben1989@...il.com>
CC:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: A simple question of a linux kernel beginner

2013-10-31 12:57 keltezéssel, Richard Weinberger írta:
> On Thu, Oct 31, 2013 at 12:31 PM, 韩磊 <bonben1989@...il.com> wrote:
>> May I can use  the ''double" as a  basic variables?
>>
>> When I define the "double" as a function return type in linux kernel,the error
>> is "error: SSE register return with SSE disabled".
>>
>> How to fix it??
> 
> Don't do it. :)
> In kernel land we don't want FPU stuff because it slows the mode switch down.
> If you *really* need to use the FPU look how the raid6 or crypto code does.

Not only it slows down the switches, but if there is no FPU, then it would
need the so-called floating-point-library. Which would slow down the code,
but the kernel needs to be as fast as it can.

-- 
Regards,
Levente Kurusa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists