(darwin-legacy pretest) about 5% slow-down of \edef in etex

[Hironori KITAGAWA]

Hello, 

> > Doing 10,000,000 times \edef\z{666} takes about 5% more time
> > with the darwin-legacy pretest compared to TeXLive 2019
> > if done with etex, but no noticeable difference with tex.
> circa 1.6s (a bit more) with etex + 2019
> circa 1.7s (a bit less) with etex + 2020

The etex format runs on the pdftex engine, and
pdftex (and also [e][u]ptex) of TeX Live 2020 compress formats by zlib.
% This feature is requested by me, because preloading expl3
% (since LaTeX 2020-02-02) increases filesize of format files.

$ ls -lh /opt/texlive/20{19,20}/texmf-var/web2c/pdftex/{e,pdfla}tex.fmt
-rw-r--r-- 1 root root 3.8M Feb  9 16:06 /opt/texlive/2019/texmf-var/web2c/pdftex/etex.fmt
-rw-r--r-- 1 root root 7.9M Feb 29 19:05 /opt/texlive/2019/texmf-var/web2c/pdftex/pdflatex.fmt
-rw-r--r-- 1 root root 1.4M Mar  6 17:20 /opt/texlive/2020/texmf-var/web2c/pdftex/etex.fmt
-rw-r--r-- 1 root root 2.3M Mar  6 17:19 /opt/texlive/2020/texmf-var/web2c/pdftex/pdflatex.fmt
$ ls -lh /opt/texlive/20{19,20}/texmf-var/web2c/eptex/platex.fmt
-rw-r--r-- 1 root root  11M Mar  1 20:56 /opt/texlive/2019/texmf-var/web2c/eptex/platex.fmt
-rw-r--r-- 1 root root 2.3M Mar  6 17:19 /opt/texlive/2020/texmf-var/web2c/eptex/platex.fmt

Regards
Hironori KITAGAWA <h_kitagawa2001 at yahoo.co.jp>