[issue39150] See if PyToken_OneChar would be faster as a lookup table

[Pablo Galindo Salgado]

Pablo Galindo Salgado <pablogsal at gmail.com> added the comment:

> PyToken_OneChar in Parser/token.c is autogenerated.  I suspect it may be faster and smaller if it were a lookup into a static table of ops rather than a switch statement.  Check to see if it is.

I suspect that it will be marginally faster (because it won't need to do bound checks to go to the default case) but under PGO it will make almost no difference.

You can try to see if there is any significant improvement using the pyperformance suite (https://pyperformance.readthedocs.io/) with and without your change (with PGO/LTO activated).

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nosy: +pablogsal

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