On Thu, 25 Jan 2024 07:41:27 GMT, Roland Westrelin <[email protected]> wrote:
> > > Naive question: the right way to use this would be almost invariably be
> > > like this:
> > > ```
> > > if (isCompileConstant(foo) && fooHasCertainStaticProperties(foo)) {
> > > // fast-path
> > > }
> > > // slow path
> > > ```
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Right?
> >
> >
> > Yes, I think so.
>
> But then whatever is in the fast path and `fooHasCertainStaticProperties` are
> never profiled because never executed by the interpreter or c1. So
> `fooHasCertainStaticProperties` will likely not be inlined and c2 will do a
> poor (or rather not as good as you'd like) job of compiling whatever is in
> the fast path.
I suppose perhaps it is implied that `fooHasCertainStaticProperties` should
have `@ForceInline` ? But yes, there seems to be several assumptions in how
this logic is supposed to be used, and at the moment, it seems to me more of a
footgun than something actually useful (but I admit my ignorance on the
subject).
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PR Comment: https://git.openjdk.org/jdk/pull/17527#issuecomment-1910140980
