[PATCH] dfa: addition of new state on demand

[Norihiro Tanaka]

When dfa builds a state, generates all next states.  However, I believe
most of them are not used.

This patch changes as that when dfa builds a state, generates a next
state including next input character only.

The following test was improved from 2.52s to 0.67s by the patch in my
machine.

$ seq -f '%g bottles of beer on the wall' 600 >600
$ time -p env LC_ALL=C src/grep -vf 600 600

$ env LC_ALL=C gcc -v
Reading specs from /usr/local/lib/gcc/x86_64-pc-linux-gnu/4.4.7/specs
Target: x86_64-pc-linux-gnu
Configured with: ./configure --with-as=/usr/local/bin/as 
--with-ld=/usr/local/bin/ld --with-system-zlib --enable-__cxa_atexit
Thread model: posix
gcc version 4.4.7 (GCC)
$ uname -a
Linux rhel6 2.6.32-642.el6.x86_64 #1 SMP Wed Apr 13 00:51:26 EDT 2016 x86_64 
x86_64 x86_64 GNU/Linux

0001-dfa-addition-of-new-state-on-demand.patch
Description: Text document