A case exposing code sink issue

[Michael Matz]

Hi,

On Thu, 24 Nov 2011, Jiangning Liu wrote:

> One more question...
> 
> Can " i = i.6_18;" be sinked out of loop, because it doesn't have memory
> dependence with others?

With current trunk the stores to i, a_p, b_p and k are sunken after the 
loop.  (There are no aliasing problems because the decls can't conflict).

What isn't sunken is the calculation of the &a[D.2248_7] expression.  
First, the number of iterations of the inner loop can't be determined by 
current code (replacing i+=k with e.g. i++ could be handled for instance).
Then this code could be handled by final value replacement, but isn't 
because interpret_rhs_expr doesn't deal with ADDR_EXPR of ARRAY_REFs.


Ciao,
Michael.