[LLVMdev] Query on optimizing away function calls.

[Frits van Bommel]

Duncan Sands wrote:
>> The "readonly" function attribute looks to be too strict for this.
> 
> It is possible to put "readonly" on the call, rather than on func2
> itself.  So if your front-end somehow knows that this use of func2
> has no real effect it could mark the call this way.

Unfortunately, it can only know that if it knows that %a won't be read from 
after the call...