Request for reviews (S): 6814842: Load shortening optimizations

[Christian Thalinger]

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?

-- Christian