On Mon, Jan 29, 2024 at 04:43:32PM -0300, Ranier Vilela wrote: > Em seg., 29 de jan. de 2024 às 16:32, Nathan Bossart < > nathandboss...@gmail.com> escreveu: >> -#define WORDNUM(x) ((x) / BITS_PER_BITMAPWORD) >> -#define BITNUM(x) ((x) % BITS_PER_BITMAPWORD) >> +#define WORDNUM(x) ((bitmapword)(x) / BITS_PER_BITMAPWORD) >> +#define BITNUM(x) ((bitmapword)(x) % BITS_PER_BITMAPWORD) >> >> I'm curious why we'd cast to bitmapword and not straight to uint32. I >> don't think the intent is that callers will provide a bitmapword to these >> macros. > > bitmapword It is the most correct and prudent option, if in the future, > we decide to change the number of nwords to uint64.
If we change nwords to a uint64, I think there will be many other changes required. Using uint32 probably trims the instructions further on machines with 64-bit pointers, too (e.g., cdqe). >> I also wonder if it's worth asserting that x is >= 0 before >> casting here. >> > I don't think this would change anything. Right, but it would offer another layer of protection against negative integers in Bitmapsets. -- Nathan Bossart Amazon Web Services: https://aws.amazon.com
