A search method for a range search with a plurality of pre-set rules constructs
a rule mapping table by dividing data associated with the rules into a plurality
of sub-keys and generating output tables for each sub-key. A rule column is formed
for a rule by following through each sub-key based on the associated range of data.
A first output table for the first sub-key and upper and lower output tables are
generated for each remaining sub-key. All the rule columns are arranged in parallel
to form the rule mapping table. The method of search is accomplished by dividing
an input data into a plurality of sub-keys and each sub-key is used to search through
the rule mapping table for determining a rule that is satisfied with the input
data. If multiple rules are satisfied, a priority encoder selects a highest priority
rule as the search result.