eliminating null pointer checks on mmu-less machines

Sat Sep 13 17:41:00 GMT 2003

>>>>> "Adam" == Adam Megacz <adam@megacz.com> writes:

Adam> Hey, I was thinking about NullPointerException handling on machines
Adam> with no MMU. There's not much that can be done for field accesses,
Adam> but method invocations are much more common.
How good a job does the optimizer do at eliminating redundant checks?
If it doesn't do so well, then I wonder whether the VRP pass (which,
as far as I know, still hasn't gone in) would help.
Another option for MMU-less machines would be to change the ABI so
that the callee checks for null `this'. That would reduce code size,
probably, perhaps at the expense of performance.
Tom