On Sat, 23 Mar 2019 08:06:35 +0900
Norihiro Tanaka <noritnk@kcn.ne.jp> wrote:

> A kwset matcher is not built in a grep matcher after token re-order is
> introduced in commit 5c7a0371823876cca7a1347fa09ca26bbbff0c98 in dfa.
> It caused performance degradation in some typical cases.  This bug is
> introduced in grep-3.2.
> 
> DFAMUST() does not work if tokens which are parsed in dfa matcher are
> re-ordered.  Therefore, change as it is called after parse and before
> tokens re-order.
> 
> BTW, this change does not affect programs that do not use DFAMUST(),
> such as sed or gawk.
> 
> $ yes $(printf '%040d' 0) | head -10000000 >inp
> $ grep-2.2/src/grep 01.2 inp
> real 1.61
> user 1.53
> sys 0.07
> $ grep-2.3/src/grep 01.2 inp
> real 1.57
> user 1.48
> sys 0.08
> $ grep-2.4/src/grep 01.2 inp
> real 1.50
> user 1.44
> sys 0.05
> $ grep-2.4.1/src/grep 01.2 inp
> real 1.53
> user 1.48
> sys 0.05
> $ grep-2.4.2/src/grep 01.2 inp
> real 1.52
> user 1.47
> sys 0.04
> $ grep-2.5.4/src/grep 01.2 inp
> real 1.53
> user 1.47
> sys 0.05
> $ grep-2.6/src/grep 01.2 inp
> real 1.51
> user 1.47
> sys 0.04
> $ grep-2.6.1/src/grep 01.2 inp
> real 1.50
> user 1.44
> sys 0.05
> $ grep-2.6.2/src/grep 01.2 inp
> real 1.52
> user 1.46
> sys 0.05
> $ grep-2.6.3/src/grep 01.2 inp
> real 1.52
> user 1.47
> sys 0.05
> $ grep-2.7/src/grep 01.2 inp
> real 1.53
> user 1.49
> sys 0.04
> $ grep-2.8/src/grep 01.2 inp
> real 1.52
> user 1.46
> sys 0.05
> $ grep-2.9/src/grep 01.2 inp
> real 1.54
> user 1.50
> sys 0.04
> $ grep-2.10/src/grep 01.2 inp
> real 1.51
> user 1.46
> sys 0.05
> $ grep-2.11/src/grep 01.2 inp
> real 1.53
> user 1.48
> sys 0.05
> $ grep-2.12/src/grep 01.2 inp
> real 1.51
> user 1.47
> sys 0.03
> $ grep-2.13/src/grep 01.2 inp
> real 1.52
> user 1.47
> sys 0.03
> $ grep-2.14/src/grep 01.2 inp
> real 1.52
> user 1.47
> sys 0.04
> $ grep-2.15/src/grep 01.2 inp
> real 1.55
> user 1.49
> sys 0.05
> $ grep-2.16/src/grep 01.2 inp
> real 1.53
> user 1.48
> sys 0.04
> $ grep-2.17/src/grep 01.2 inp
> real 1.53
> user 1.48
> sys 0.05
> $ grep-2.18/src/grep 01.2 inp
> real 1.51
> user 1.44
> sys 0.06
> $ grep-2.19/src/grep 01.2 inp
> real 0.06
> user 0.02
> sys 0.04
> $ grep-2.20/src/grep 01.2 inp
> real 0.07
> user 0.01
> sys 0.05
> $ grep-2.21/src/grep 01.2 inp
> real 0.06
> user 0.02
> sys 0.04
> $ grep-2.22/src/grep 01.2 inp
> real 0.06
> user 0.01
> sys 0.05
> $ grep-2.23/src/grep 01.2 inp
> real 0.09
> user 0.04
> sys 0.05
> $ grep-2.24/src/grep 01.2 inp
> real 0.09
> user 0.04
> sys 0.04
> $ grep-2.25/src/grep 01.2 inp
> real 0.09
> user 0.05
> sys 0.04
> $ grep-2.26/src/grep 01.2 inp
> real 0.09
> user 0.04
> sys 0.05
> $ grep-2.27/src/grep 01.2 inp
> real 0.09
> user 0.04
> sys 0.04
> $ grep-2.28/src/grep 01.2 inp
> real 0.09
> user 0.04
> sys 0.04
> $ grep-3.0/src/grep 01.2 inp
> real 0.09
> user 0.04
> sys 0.04
> $ grep-3.1/src/grep 01.2 inp
> real 0.11
> user 0.05
> sys 0.06
> $ grep-3.2/src/grep 01.2 inp
> real 0.37
> user 0.32
> sys 0.04
> $ grep-3.3/src/grep 01.2 inp
> real 0.29
> user 0.25
> sys 0.04
> 
> Thanks,
> Norihiro

Missing a patch for dfa.  Re-send correct patch file.