Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-08 Thread Kewen.Lin
Hi Bin, > I am a bit worried that would make IVOPTs heavy too, it might be > possible to compute heuristics whether loop should be unrolled as a > post-IVOPTs transformation. Of course the transformation needs to do > more work than simply unrolling in order to take advantage of > aforementioned

Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-08 Thread Segher Boessenkool
On Wed, Jan 08, 2020 at 07:12:29PM +0800, Bin.Cheng wrote: > I am a bit worried that would make IVOPTs heavy too, Yeah. And ivopts already *is* heavy, by nature of what it does. Giving it extra work to do is not a good idea imo. > it might be > possible to compute heuristics whether loop should

Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-08 Thread Bin.Cheng
On Tue, Jan 7, 2020 at 6:48 PM Kewen.Lin wrote: > > on 2020/1/7 下午5:14, Richard Biener wrote: > > On Mon, 6 Jan 2020, Kewen.Lin wrote: > > > >> We are thinking whether it can be handled in IVOPTs instead of one RTL > >> pass. > >> > >> During IVOPTs selecting IV cands, it doesn't know the loop wi

Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-07 Thread Kewen.Lin
on 2020/1/7 下午7:25, Richard Biener wrote: > On Tue, 7 Jan 2020, Kewen.Lin wrote: > >> on 2020/1/7 下午5:14, Richard Biener wrote: >>> On Mon, 6 Jan 2020, Kewen.Lin wrote: >>> We are thinking whether it can be handled in IVOPTs instead of one RTL pass. During IVOPTs selecting IV

Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-07 Thread Richard Biener
On Tue, 7 Jan 2020, Kewen.Lin wrote: > on 2020/1/7 下午5:14, Richard Biener wrote: > > On Mon, 6 Jan 2020, Kewen.Lin wrote: > > > >> We are thinking whether it can be handled in IVOPTs instead of one RTL > >> pass. > >> > >> During IVOPTs selecting IV cands, it doesn't know the loop will be > >>

Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-07 Thread Kewen.Lin
on 2020/1/7 下午5:14, Richard Biener wrote: > On Mon, 6 Jan 2020, Kewen.Lin wrote: > >> We are thinking whether it can be handled in IVOPTs instead of one RTL pass. >> >> During IVOPTs selecting IV cands, it doesn't know the loop will be unrolled >> so >> it doesn't count the possible step cost in

Re: [RFC] IVOPTs select cand with preferred D-form access

2020-01-07 Thread Richard Biener
On Mon, 6 Jan 2020, Kewen.Lin wrote: > Hi all, > > Recently I'm investigating on an issue related to use D-form/X-form vector > memory access, it's the same as what the patch > https://gcc.gnu.org/ml/gcc-patches/2019-10/msg01879.html > was intended to deal with. Power9 introduces DQ-form instru