On Mon, Jul 6, 2015 at 12:02 PM, Ajit Kumar Agarwal <ajit.kumar.agar...@xilinx.com> wrote: > > > -----Original Message----- > From: Bin.Cheng [mailto:amker.ch...@gmail.com] > Sent: Monday, July 06, 2015 7:04 AM > To: Steven Bosscher > Cc: Ajit Kumar Agarwal; l...@redhat.com; Richard Biener; gcc@gcc.gnu.org; > Vinod Kathail; Shail Aditya Gupta; Vidhumouli Hunsigida; Nagaraju Mekala > Subject: Re: Live on Exit renaming. > > On Mon, Jul 6, 2015 at 6:02 AM, Steven Bosscher <stevenb....@gmail.com> wrote: >> On Sat, Jul 4, 2015 at 3:45 PM, Ajit Kumar Agarwal wrote: >>> I am not sure why the above optimization is not implemented in GCC. >> >> -fsplit-ivs-in-unroller > >>>And thing might have changed. Given the condition GCC does IVO on gimple, >>>unrolling on RTL, there is inconsistency between the two optimizer since IVO >>>>>takes register pressure of IVs into consideration and assumes IVs will >>>take single registers. At least for some cases, splitting live range of IVs >>>results in bad >>code. See PR29256 for more information. As described in >>>the comment, actually I am going to do some experiments disabling such >>>transformation to see >>what happens. > > The above optimization is implemented as a part of unroller in gimple. There > is an unroller pass in rtl which does not have support for this As far as I understand, fsplit-ivs-in-unroller is a transformation in RTL unroller.
Thanks, bin > optimization. Shouldn't be the fsplit-ivs-in-unroller optimization > implemented in the unroller pass of rtl. I am looking at the implementation > perspective for implementing the fsplit-ivs-in-unroller optimizations in the > unroller rtl pass. > > Thanks & Regards > Ajit > > Thanks, > bin >> >> Ciao! >> Steven
