[PATCH][1/3][ARM] Keep ctz expressions together until after reload

2016-05-26 Thread Kyrill Tkachov
Hi all, On arm we don't have a dedicated instruction that corresponds to a CTZ rtx but we synthesise it with an RBIT instruction followed by a CLZ. This is currently done at expand time. However, I'd like to push that step until after reload and keep the CTZ rtx as a single whole in the early

Re: [PATCH][1/3][ARM] Keep ctz expressions together until after reload

2016-05-26 Thread Joseph Myers
On Thu, 26 May 2016, Kyrill Tkachov wrote: > the early RTL optimisers. This better expresses the semantics of the > operation as a whole, since the RBIT operation is represented as an > UNSPEC anyway and so will not see the benefits of combine, This doesn't affect your patch, but I think it wo

Re: [PATCH][1/3][ARM] Keep ctz expressions together until after reload

2016-06-06 Thread Kyrill Tkachov
Ping. https://gcc.gnu.org/ml/gcc-patches/2016-05/msg02078.html Patches 1 and 3 have been approved. Thanks, Kyrill On 26/05/16 10:52, Kyrill Tkachov wrote: Hi all, On arm we don't have a dedicated instruction that corresponds to a CTZ rtx but we synthesise it with an RBIT instruction followed

Re: [PATCH][1/3][ARM] Keep ctz expressions together until after reload

2016-06-06 Thread Ramana Radhakrishnan
On Thu, May 26, 2016 at 10:52 AM, Kyrill Tkachov wrote: > Hi all, > > On arm we don't have a dedicated instruction that corresponds to a CTZ rtx > but we synthesise it > with an RBIT instruction followed by a CLZ. This is currently done at expand > time. > However, I'd like to push that step until