Re: use __builtin_clz to compute most significant bit set

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От Magnus Hagander
Тема Re: use __builtin_clz to compute most significant bit set
Дата
Msg-id CABUevEzPTbDE=YaVwFTrZJx9OCF-qSnHe1iqgfuH2JTVgELpOw@mail.gmail.com
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Ответ на use __builtin_clz to compute most significant bit set  (Joseph Yu <kiddo831007@gmail.com>)
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On Sat, Feb 25, 2023 at 9:32 PM Joseph Yu <kiddo831007@gmail.com> wrote:
hi community

This is the first time for me to submit a patch to Postgres community.

instead of using for loop to find the most significant bit set. we could use __builtin_clz function to first find the number of leading zeros for the mask and then we can find the index by 32 - __builtin_clz(mask).

Hi!

This file has already been removed, as of 4f1f5a7f85. Which already uses __builtin_clz if it' available.

Were you perhaps looking at an old version instead of the master branch?


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