+++ This bug was initially created as a clone of Bug #206972 +++ I am seeing the same behaviour, but I am not using -ffast-math.
Created attachment 200262 [details] emerge --info
kmplot 3.5.7 is no longer in tree. Please try with 3.5.10.
I am seeing the same behaviour in kmplot 3.5.10.
KDE 3.5.10 has been masked for removal, this won't be fixed...