On Thu, Oct 17, 2013 at 09:56:31AM +0200, Richard Biener wrote:
> off-noise (more than 5s difference) may be 462.libquantum and
> 459.GemsFDTD. I didn't include unpatched trunk in the comparison
> (not fixing the bug isn't an option after all).
>
> Conceptually I like the rewriting into unsigned arithmetic more
> so I'm going to apply that variant later today (re-testing 3
> runs of 462.libquantum and 459.GemsFDTD, this time with address-space
> randomization turned off).
Can't we rewrite for the selected arithmetic operations and punt (is that
what Bernd's patch did) on moving other arithmetics? Well, there are
operations that are safe even for signed types, e.g. rotates, isn't
RSHIFT_EXPR also safe?
Can't you handle also LSHIFT_EXPR (or do we treat it even signed as never
undefined in the middle-end/backend?).
Jakub
