On 18/07/11 15:46, Richard Guenther wrote:
> Will signedness be always the same?  Usually the canonical check to
> use would be !useless_type_conversion_p (type, TREE_TYPE (add_rhs)).

The signedness ought to be unimportant - any extend will be based on the 
source type, and the signedness should not affect the addition 
operation. That said, it really ought to remain correct or else bad 
things could happen in later optimizations ....

Here is the patch I plan to commit, when patch 1 is approved, and my 
testing is complete.

Andrew