Request for reviews (M): 7170463: C2 should recognize "obj.getClass() == A.class" code pattern
john.r.rose at oracle.com
Wed May 23 22:02:47 PDT 2012
On May 23, 2012, at 4:47 PM, Vladimir Kozlov wrote:
> I updated webrev:
> I found additional issue with original changes. They accidentally removed optimization which replaces LoadKlass node with ConP (klass type) in map. Next code will not be executed:
> cast = con; // Replace non-constant val by con.
> New code should do separate map update of object which klass is compared.
That's fine; I like it.
New question: Can the following call return Top?
Number x = 5;
if (x.getClass() == String.class)
Perhaps the compare will short-circuit before that happens. If it doesn't, we'll get assertion failures or worse.
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