Smartmatch is experimental at backwards_replace.pl line 58. Original String: abcdefABCDEF unpack_C_pack: abcdefABKDEF regex_match_start: abcdefABKDEF rindex_substr: abcdefABKDEF regex_match_end: abcdefABKDEF unpack_U_pack: abcdefABKDEF reverse_regex: abcdefABKDEF rindex_substr_max: abcdefABKDEF regex_with_K: abcdefABKDEF for_smartmatch: abcdefABKDEF Using new string for Benchmark. String Length: 5000 Rate regex_match_end unpack_U_pack unpack_C_pack reverse_regex regex_match_start for_smartmatch regex_with_K rindex_substr rindex_substr_max regex_match_end 373/s -- -91% -93% -100% -100% -100% -100% -100% -100% unpack_U_pack 4267/s 1045% -- -17% -98% -98% -98% -98% -99% -99% unpack_C_pack 5168/s 1287% 21% -- -97% -97% -97% -98% -99% -99% reverse_regex 170836/s 45745% 3904% 3205% -- -10% -11% -24% -52% -80% regex_match_start 189150/s 50659% 4333% 3560% 11% -- -1% -16% -47% -77% for_smartmatch 190934/s 51138% 4375% 3594% 12% 1% -- -15% -46% -77% regex_with_K 224878/s 60247% 5171% 4251% 32% 19% 18% -- -37% -73% rindex_substr 355071/s 95185% 8222% 6770% 108% 88% 86% 58% -- -57% rindex_substr_max 835106/s 224004% 19473% 16058% 389% 342% 337% 271% 135% --