• via Digitalmars-d-bugs (30/30) Feb 08 2017 https://issues.dlang.org/show_bug.cgi?id=17161

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

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: nobody puremagic.com
          Reporter: jack 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


$ /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



$ 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

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