Non-call exceptions versus cse

[Richard Henderson]

On Tue, Nov 19, 2002 at 04:21:29PM +0000, Andrew Haley wrote:
> Consider this code fragment:
> 
> int nn = 0;
> try
> {
>     int tmp = foo->bar;
>     nn = tmp;
> }
> ...
> 
> When using non-call exceptions, this may not be changed to
> 
> int nn = 0;
> try
> {
>     nn = foo->bar;
> }

Huh?

I don't see that these two are going to be any different at all.
The value must be loaded from foo->bar before it can be stored 
in nn.  This is true even if you have mem->mem moves, since the
source might cause a normal page fault as well.

Please explain the problem you're actaully seeing in more detail.


r~