On Wed, Aug 27, 2014 at 10:10 AM, Bin Cheng <bin.ch...@arm.com> wrote:
> Hi,
> As I analyzed in bug pr62178, current candidate selecting algorithm can't
> find out the optimal solution in some scenarios. I am trying to improve it
> but before that, I need to clean up the interface of iv_ca_add_use and the
> calls to it. The two calls to the function are controlled by a boolean
> argument, and the second call is always fired if the first one doesn't give
> any result. This patch encapsulates logic of the two calls into function
> iv_ca_add_use and cleanups the interface.
> Another change is remove the check in below code.
>
> gcc_assert (ivs->upto >= use->id);
>
> if (ivs->upto == use->id)
> {
> ivs->upto++;
> ivs->bad_uses++;
> }
>
> It can be proved in an inductive approach that ivs->up_to always equals to
> use->id at the position.
>
> This patch does not change code logic at all, anyway, it passes bootstrap
> and regtest on x86_64/x86. So is it OK?
Ok (I suppose you checked that it really generates the same code on
a set of files?)
Thanks,
Richard.
> Thanks,
> bin
>
> 2014-08-27 Bin Cheng <bin.ch...@arm.com>
>
> * tree-ssa-loop-ivopts.c (iv_ca_add_use): Delete parameter
> important_candidates. Consider all important candidates if
> IVS doesn't give any result. Remove check on ivs->upto.
> (try_add_cand_for): Call iv_ca_add_use only once.
