[issue36551] Optimize list comprehensions with preallocate size and protect against overflow

[anthony shaw]

anthony shaw <anthony.p.shaw at gmail.com> added the comment:

> This patch makes it slow for small iterators

That is a one-off cost for the __length_hint__ of the range object specifically.
Objects with a known length (lists, sets, tuples) would not have that overhead.

I can run a more useful set of benchmarks against this.

So the +0.6us would be the same for ranges 8-16. Then less for 16-25, then again for 25-35 as the removal of the reallocation process has a more significant factor for larger ranges.

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nosy:  -pablogsal

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<https://bugs.python.org/issue36551>
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