Request for reviews (S): 6814842: Load shortening optimizations
Christian.Thalinger at Sun.COM
Mon Mar 9 11:41:17 PDT 2009
On Mon, 2009-03-09 at 11:24 -0700, Tom Rodriguez wrote:
> You can't simply replace a load of one size with a load of a different
> size without dealing with the endianness issue.
Yes, I don't deal with that right now.
> Even if you deal with
> that, I also think there are issues with alias analysis understanding
> that a load at +3 within an int is in the same alias class as a load
> at +0. The current code assumes that operations start at the
> beginning of the field. I'm also not sure the rest of the system will
> be very happy with non-int loads on an int memory slice. I think a
> lot of testing would be required for such a change.
I see. Sounds like too much work and possible problems for such a small
(probably not very often applied) optimization. Should I drop it?
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