On 2021-08-13 14:40:08 +0300, Yura Sokolov wrote: > Ranier Vilela писал 2021-08-13 14:12: > > Em sex., 13 de ago. de 2021 às 07:15, Andres Freund > > <and...@anarazel.de> escreveu: > > > Personally I find it more obvious to understand the intended > > > behaviour > > > with ~0 (i.e. all bits set) than with a width truncation. > > > > https://godbolt.org/z/57WcjKqMj > > The generated code is identical. > > I believe, you mean https://godbolt.org/z/qWzE1ePTE
I don't think the choice of instructions matters. This is called around creation and resizing - the other costs are several orders of magnitude more expensive than determining the mask.
