From: Matthew Fernandez <matthew.fernandez@nicta.com.au>
To: <musl@lists.openwall.com>
Subject: 64-bit atomic ops on 32-bit ARM
Date: Thu, 6 Feb 2014 09:56:47 +1100 [thread overview]
Message-ID: <52F2C1AF.8020903@nicta.com.au> (raw)
Hi all,
The header atomic.h contains a couple of functions for operations on 64-bit types. Despite their
name, these do not appear to be atomic to me. For example:
static inline void a_and_64(volatile uint64_t *p, uint64_t v)
{
union { uint64_t v; uint32_t r[2]; } u = { v };
a_and((int *)p, u.r[0]);
a_and((int *)p+1, u.r[1]);
}
Have I misunderstood something or is there some other reason behind their implementation? AIUI on
certain ARM platforms there is actually no way to implement atomic 64-bit ops without kernel support.
If replying, please CC me directly as I'm not on the list.
Thanks,
Matt
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next reply other threads:[~2014-02-05 22:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-05 22:56 Matthew Fernandez [this message]
2014-02-05 23:06 ` Rich Felker
2014-02-05 23:08 ` Matthew Fernandez
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