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7142a3debb
Since the dynamic AR-table refactoring, `Hash.new(capacity:)` no longer allocate the ideal size for capacity `<= 8`, because the capacity allocation happens in `#initialize`, hence after the slot has been allocated. To solve that, we have to define a custom `.new` method, so we can parse the `capacity:` argument prior to the slot allocation, similar to how it's done for `String`. However defining a custom `new` disable the `opt_new` optimization, so to counter-act that we have to add a special branch in `opt_new` to handle hash specifically, and parse the `capacity:` argument without having to allocate a keyword arguments hash. | |compare-ruby|built-ruby| |:-------------------|-----------:|---------:| |new | 21.185M| 24.041M| | | -| 1.13x| |new_8 | 10.419M| 19.930M| | | -| 1.91x| |new_index_8 | 22.113k| 22.534k| | | -| 1.02x| |new_capa_index_8 | 21.786k| 22.455k| | | -| 1.03x| |to_h_8 | 21.510k| 20.655k| | | 1.04x| -| |new_with_capa_1k | 21.047k| 21.933k| | | -| 1.04x| |new_with_capa_100k | 209.952| 207.936| | | 1.01x| -|