Represents a single bit range of inputs from phv. ixbar_bit_position - the start_bit on the 1024 bit IXBar bit_size - the bits in the input symmetric_info - contains info regarding symmetric hashing. If 2 fields f1 and f2 need to be symmetric, then their respective "sib_sym_group" need to point to the other's group. Their respective order in the input ixbar vec in honored. So the first input encountered having sibling group 2, self 1, we search for the first input having self group 2. valid - whether a hash matrix should be calculated for this input, only used when type is tPHV constant - constant value in a hash field list. current max size is 64 bit. This is a software constraint. User can write multiple constant values in a field list if a larger constant is needed.