Dear Eigen deveopers.
we are in Debian are having bugreport #836844  which detects the matrix multiplication problem on ppc64 platform.
I hope that the solution for this bug is already found, see the following answer . But we need of course the confirmation from upstream. We have a corresponding hardware to test it.
I'm moving this to vectorization. (So hopefully Markos can have a look at it).
I guess pnegate(const Packet4f& a) should also use negative zero then?
Going to test this with proposed negative zero on my ppc64le system and will update the ticket, sorry for the delay in replying, but it is an extremely busy period for me.
(tested on gcc farm)
sorry, I missed the discussion. Thanks for fixing it, we will integrate into Debian this fix as fast as possible.