On Wed, 2023-01-18 at 17:49 +0100, Alexander Lobakin wrote: > > Aaaah right. Seems like we can't avoid introducing a separate macro for > that. I like the idea of your patch anyways! :) > One note re __BF_CHECK_POW2(): can't we reuse is_power_of_2() anyhow? > Foe example, by deriving the code of the latter into a macro and then > using it in both? > Well, not directly - for example is_power_of_2() doesn't accept 0, while we want to accept 0 (mask being e.g. "0xfull<<60", we already check for mask != 0). I thought about __BUILD_BUG_ON_NOT_POWER_OF_2 but it uses BUILD_BUG_ON, not BUILD_BUG_ON_ZERO, and BUILD_BUG_ON is nicer in most contexts ... So you could pull out the expression "((n) & ((n) - 1)) != 0" from all four of these, but it doesn't feel worth it. johannes
