Possible bug in softfloat

[Adrian Chadd]

You can easily fire up a mips32 / mips64 emulator build - cross-build
a world+kernel, build an image, then run qemu-devel to boot it.

https://wiki.freebsd.org/FreeBSD/MipsEmulation

You should be able to get a 32 bit soft-float mips environment inside
there which you can use to trigger it.
(And also run whatever other floating point validation suite you may hvae.)



-adrian


On 28 November 2014 at 11:07, Steve Kargl
<sgk at troutmask.apl.washington.edu> wrote:
> On Fri, Nov 28, 2014 at 10:54:25AM -0800, Adrian Chadd wrote:
>> On 28 November 2014 at 10:34, Steve Kargl
>> <sgk at troutmask.apl.washington.edu> wrote:
>> > In a thread on comp.lang.c, it was pointed out that softfloat
>> > has a bug and in checking src/lib/libc/softfloat I confimed
>> > the issue is present in FreeBSD.  What I hae not confirmed
>> > is whether or not it is possible to hit this bug.  In fact,
>> > it may only hit arm and mips.  Anyway, here's the patch
>>
>> So we should just commit this?
>>
>
> I suspect the answer is yes, but I have no idea on how
> to trigger this code path.  I also have no access to
> arm or mips hardware where the problem may manifest only.
>
> It may also be appropriate to have someone else confirm
> that the patch is indeed correct.
>
> --
> steve