A processor unit can rapidly search a string of characters. The processor unit includes vector registers each having M vector elements, each having n bits of data for containing an encoded character. An M×M matrix of comparators within the processor unit can be used to compare elements of a first register storing a reference string and elements of a second register storing a target string. A logic gate is associated with each upper diagonal of the matrix of comparators and is configured to combine the results of comparators along the diagonal, resulting in a bit vector indicating characters of the target string that fully match the reference string and characters that partially match the reference string. The processor unit result generating logic generates, using the resulting bit vector, an indication of a substring of the target string that matches a fragment of the reference string.