[luatex] Removing the zero-initialization of an array can speedup LuaTeX on plain TeX document by 25%

[Joseph Wright]

On 01/09/2024 07:53, Joseph Wright wrote:
> On 01/09/2024 01:28, Reinhard Kotucha via luatex wrote:
>> Regarding performance tests, there are a few things worth to be
>> mentioned.  You get different results in different environments.
>> First of all, in TeX Live luatex.ini contains the line
>>
>>    \input load-unicode-data.tex
>>
>> This huge file blows up the format file and increases startup time
>> significantly.  AFAIK it's currently only used by LaTeX and can be safely
>> removed from all plain TeX formats.
>
> load-unicode-data.tex initialises the values for \uccode, \lccode and
> \sfcode based on the current Unicode release. As such, it's intended to
> set up for unpredictable character set usage: if you know which
> codepoints will be used, you could avoid this, but in a general sense
> that's not true. Perhaps you are thinking of the additional data loaded
> in the LaTeX format by expl3, and used for things that are not covered
> by the classical TeX structures (e.g. one-to-many case changing)?

Oh, and \catcode

Joseph