https://issues.dlang.org/show_bug.cgi?id=17161
Issue ID: 17161 Summary: [REG 2.072.2] Massive Regex Slowdown Product: D Version: D2 Hardware: All OS: All Status: NEW Severity: regression Priority: P1 Component: phobos Assignee: nob...@puremagic.com Reporter: j...@jackstouffer.com Created attachment 1636 --> https://issues.dlang.org/attachment.cgi?id=1636&action=edit The sample code 8x slower. Not noticeable on smaller files. The input file to reproduce is too large to post here. You can generate it by running the python code here: https://benchmarksgame.alioth.debian.org/u64q/program.php?test=fasta&lang=python3&id=3 $ python3 fasta.py 5000000 > input5000000.txt # 2.072.2 $ /Users/Jack/digger/result/bin/dmd -O -inline -release -boundscheck=off slow.d $ cat input5000000.txt | time ./slow ./slow 2.19s user 0.09s system 97% cpu 2.330 total # 2.073.0 $ dmd -O -inline -release -boundscheck=off slow.d $ cat input5000000.txt | time ./slow ./slow 18.23s user 0.16s system 98% cpu 18.616 total --