Messages in this thread | | | From | Segher Boessenkool <> | Subject | Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures | Date | Sat, 18 Aug 2007 00:49:08 +0200 |
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> #define forget(a) __asm__ __volatile__ ("" :"=m" (a) :"m" (a)) > > [ This is exactly equivalent to using "+m" in the constraints, as > recently > explained on a GCC list somewhere, in response to the patch in my > bitops > series a few weeks back where I thought "+m" was bogus. ]
[It wasn't explained on a GCC list in response to your patch, as far as I can see -- if I missed it, please point me to an archived version of it].
One last time: it isn't equivalent on older (but still supported by Linux) versions of GCC. Current versions of GCC allow it, but it has no documented behaviour at all, so use it at your own risk.
Segher
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