David Rowley <dgrowle...@gmail.com> writes:
> The following comment above #define PAGES_PER_CHUNK in tibbitmap.c appears
> to be incorrect:
> "But we
> * also want PAGES_PER_CHUNK to be a power of 2 to avoid expensive integer
> * remainder operations. So, define it like this:"
> I don't quite follow this as it does nothing of the kind.
> Check tbm_page_is_lossy() where we do: bitno = pageno % PAGES_PER_CHUNK;
> Or am I missing something about the compiler optimizing that to: bitno =
> pageno & 255; ?
Exactly. Any C compiler ever written will do that.
regards, tom lane
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