Re: [cxx-mem-model] Generic atomic functions

[Andrew MacLeod <amacleod at redhat dot com>]

On 10/25/2011 02:18 PM, Richard Henderson wrote:
> On 10/25/2011 10:20 AM, Andrew MacLeod wrote:
> > +   /* Otherwise there is a lockfree match, transform the call from:
> > +        void fn(T* mem, T* desired, T* return, model)
> > +      into
> > +        *((In *)return = fn (T* mem, *((In *)desired, model)  */
> This is, in general, an aliasing violation nearly guaranteed to fail.
> Instead try
>
>    *return = VCE<In>(fn(mem, VCE<In>(*desired), model))
>
> where VCE<T>(E) is a VIEW_CONVERT_EXPR with TREE_TYPE = T and a
> first operand expression of E.
>
> But in particular, the actual stores and loads happen in the original type.
OK, how's this.  (just the c-common.c file)

It seems to work fine. Past all the basic tests, and bootstraps in an 
incremental bootstrap.  I'll kick off a full scratch bootstrap/test 
before feeling all warm and fuzzy tho :-)

Andrew

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