> > I wanted to mention it and then forgot, but yes, those variables are
> > of external scope, as they are instance variables of an objc object.
> > They are thus members of a struct, which is passed by ref to the
> > function (as objc objects are pointers to struct). So yes, this is
> > probably the problem. I never thought of it in this particular
> > configuration... Is the fix to use a local variable instead? Something
Yes. The compiler is reloading your pointers on every loop iteration because
it can't tell whether your stores alias to those pointers (which means the
ptr value could change from one iteration to the next).
Shark says:
"Common causes of invariant loads within a loop are a pointer dereference
within the loop or use of a global variable. You can eliminate this
inefficiency by using a temporary local variable within the loop."
You should consider unrolling the loop too.
--Sanjay
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