Re: [bug-gawk] Increased RAM memory usage in gawk 5.0.1 compared to gawk 4.1.4

[Andrew J. Schorr]

On Sun, Aug 11, 2019 at 07:42:37AM -0600, address@hidden wrote:
> BTW, your change to disable the 4.2 IGNORECASE speed-up is fine for your
> program, which doesn't use IGNORECASE, but is wrong for the general
> case, so I cannot include it in the code base.

Mightn't it be possible to stop populating re_reg[1] with the ignorecase
variant when the node is created and instead populate it only when needed?
As far as I can tell from a cursory inspection, the only place that 
re_reg[IGNORECASE]
is accessed is from re.c:re_update. Could it make sense then to populate the
regexps on a lazy basis from that function when they are needed? I guess
this could be done for both the regular and IGNORECASE variants, but maybe
the regexp needs to be compiled initially to give timely error messages...

Regards,
Andy