Trivial Description
The current implementation of floatToSortableInt does not account for different NaN ranges which may result in NaNs sorted before -Infinity and after +Infinity. The default Java ordering is: all NaNs after Infinity.
A possible fix is to make all NaNs canonic "quiet NaN" as in:
// Canonicalize NaN ranges. I assume this check will be faster here than // (v == v) == false on the FPU? We don't distinguish between different // flavors of NaNs here (see http://en.wikipedia.org/wiki/NaN). I guess // in Java this doesn't matter much anyway. if ((v & 0x7fffffff) > 0x7f800000) { // Apply the logic below to a canonical "quiet NaN" return 0x7fc00000 ^ 0x80000000; }
I don't commit because I don't know how much of the existing stuff relies on this (nobody should be keeping different NaNs in their indexes, but who knows...).