This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] Fix underflow and inexact signalling in soft-fp whenpacking.

On Fri, 25 May 2012, David Miller wrote:

> I think part of all of these problems is that things come out a little
> bit differently from the FP_DIV macro.  For example, for double
> operation:

It's quite possible one of the several FP_DIV implementations has a bug, 
but if they return results that don't have the highest set bit in the 
standard position I'd say that's a bug in the relevant implementation, and 
should be fixed there.  The ones I looked at compared the two mantissas at 
the start to work out the desired exponent, but maybe they get the case of 
equality wrong, or something like that.

I basically did not touch FP_DIV at all in my 2005-6 changes.

> BTW, kernel commit f8324e20f8289dffc646d64366332e05eaacab25 fixes
> another bug that we might have in the glibc and libgcc copies.  I
> haven't looked more deeply at this yet, but it is on my TODO list.

I just cleared that from my todo list, see my previous message - it was 
GCC bug 44631 (closed as invalid when it was found to be a kernel bug) and 
was fixed by my 2005-6 changes.

Joseph S. Myers

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]