java aliasing rules

Wed Mar 27 16:45:00 GMT 2002

>>>>> "Bryce" == Bryce McKinlay <bryce@waitaki.otago.ac.nz> writes:

Bryce> I implemented java_get_alias_set() by simply assigning a new
Bryce> alias set to every unique field, storing it in
Bryce> DECL_POINTER_ALIAS_SET for each FIELD_DECL. This managed to
Bryce> eliminate some redundant loads in my tests, but didn't cause
Bryce> any measurable improvements in benchmark scores so I didn't get
Bryce> too excited about it
This sounds like a nice approach.
My only question is how it handles the length field of an array.
Object[].length and Foo[].length can alias.
But int[].length and Object[].length cannot.
Similarly for the interior of arrays.
Maybe we could squeeze out some tiny percentage improvement by taking
this into account too?
Tom