FIND REGULAR EXPRESSION INSTRUCTION ON SUBSTRING OF LARGER STRING

A technique for pattern matching is provided. A processing circuit receives an input string streamed in as input, and the input string is designated into substrings according to predefined bytes. A first substring of the substrings is in a first register to be compared against a pattern of the predefined bytes in a second register. The processing circuit compares the first substring in the first register to the pattern in the second register according to a type of evaluations specified in a third register, and determines state information that includes a number of states achieved for the pattern based on the comparison. The state information is stored in a fourth register to be utilized in a next run for a next substring of the substrings making up the input string, where the next run builds from the state information in the fourth register.