Intel® Fortran Compiler 16.0 User and Reference Guide
When bit sequences of unequal length are compared, the shorter sequence is padded with zero bits on the left, so that it is the same length as the longer sequence.
Bit sequences are compared from left to right, one bit at a time, until unequal bits are found, or until all bits have been compared and found to be equal.
If unequal bits are found, the sequence with zero in the unequal position is considered to be less than the sequence with one in the unequal position. Otherwise the sequences are considered to be equal.