Re: earmv6hf IEEE754 underflow problem

[Richard Earnshaw <Richard.Earnshaw%buzzard.freeserve.co.uk@localhost>]

On 23/02/15 20:31, Tobias Nygren wrote:
> On Mon, 23 Feb 2015 20:42:23 +0100
> Martin Husemann <martin%duskware.de@localhost> wrote:
> 
>> On Mon, Feb 23, 2015 at 08:38:36PM +0100, Tobias Nygren wrote:
>>> Ah, I see. That explains the problem, thank you. But the BCM2835 VFP
>>> hardware itself does have some exception support, doesn't it?
>>
>> I don't know - that output was from a Cortex A7 CPU (and would probably
>> be the same for RPi2), but I don't have a RPi myself.
> 
> The ARM1176JZF-S manual says
> 
> "The VFP supports all five floating point exceptions defined by the
> IEEE 754 standard"
> 
> Also
> 
> rpi# dmesg |grep exceptions
> vfp0 at cpu0: VFP11, rounding, exceptions
> 
> ... but the userland does not have any of the fenv(3) stuff so
> I suppose it's still missing some code. Maybe this would be a good
> google SoC project?
> 
> Cheers,
> -Tobias
> 


You might also want to check

http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0301h/Babfbcac.html

R.