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Re: 64-bit masks
Sad Clouds <cryintothebluesky%googlemail.com@localhost> wrote:
> 1. What is the correct (portable?) way of specifying 64-bit constants?
> If I need a 64-bit constant set to all 1s, will the following work on all
> unit64_t num = 0xffffffffffffffffULL;
I would use ~0ULL.
> 2. I have an array of 64 objects that I need to keep track of. I keep
> their state (i.e. busy/free) in a 64-bit mask, 1 for busy, 0 for free.
> unit64_t state;
How about uint32_t state; ? To mark/unmark bit, it would be a matter
of shifting and masking. In a case you would want to use ffs()/ffs32(),
popcount(), atomic operations or similar routines - it might be better.
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