When compiling on DECstation running Ultrix 4.0 a command 'cc -c -O
regex.c' is causing an infinite loop in an optimizer.  Other sources
compile fine with -O flag.  If you are going to use this flag either
add a special rule to Makefile for a compilation of regex.c, or issue
'cc -c regex.c' before hitting 'make'.

From:	Steve Simmons <scs@wotan.iti.org>
Subject: Non-bug report on gawk 2.13.2
To:	david@cs.dal.ca, arnold@skeeve.atl.ga.us
Date:	Thu, 25 Jul 1991 13:45:38 -0300

Just fyi -- it passes tests with flying colors under Ultrix 4.2.  The
README.ultrix file applies more than ever.  You might want to add
these paragraphs to it:

 As of Ultrix 4.2 the optimise works for regex.c, but you must give an
 additional switch to get everything optimised.  Using '-Olimit 1500'
 does the job.  Without the switch gawk will compile and run correctly,
 but you will get complaints about lost optimisations in builtin.c,
 awk.tab.c and regex.c.

 The configure for ultrix4.1 works just fine for ultrix4.2