Messages in this thread | | | Date | Mon, 29 Nov 2010 13:33:33 -0500 | From | Mathieu Desnoyers <> | Subject | Re: [thisops uV2 04/10] x86: Support for this_cpu_add,sub,dec,inc_return |
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* Christoph Lameter (cl@linux.com) wrote: > On Sat, 27 Nov 2010, Mathieu Desnoyers wrote: > > > > +/* > > > + * Add return operation > > > + */ > > > +#define percpu_add_return_op(var, val) \ > > > +({ \ > > > + typedef typeof(var) pao_T__; \ > > > + typeof(var) pfo_ret__ = val; \ > > > + if (0) { \ > > > + pao_T__ pao_tmp__; \ > > > + pao_tmp__ = (val); \ > > > + (void)pao_tmp__; \ > > > + } \ > > > > OK, I'm dumb: why is the above needed ? > > Ensure that the compiler agrees that *var and val are compatible. Taken > over from percpu_add_op().
Isn't that the purpose of __builtin_types_compatible_p(t1, t2) ?
Mathieu
-- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com
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