On Tue, Sep 1, 2015 at 7:57 PM, Ajit Kumar Agarwal <ajit.kumar.agar...@xilinx.com> wrote: > All; > > The Global code motion are the important optimization that have an impact on > register spills and Fetch. Thus > The Global code motion takes into account the increase or decrease of > register pressure. > > Strength Reductions is an important optimization that has an impact on > register pressure. The strength reduction > Optimizations doesn't take into account the register pressure and especially > the strength reduction for induction > Variables that are inside the Loops. Loops are the bottleneck for the > register pressure and any spill inside the loops > Based on strength reduction of induction variables degrades the performance > of the Loops. > > Thus the strength reductions in general and especially the strength reduction > for induction variables should take > Into account the register pressure based on Live range info. > > I don't think we do take into account the register pressure for strength > reduction optimization in general and especially the > Strength reduction based on induction variables.
We do loop strength reduction as part of induction variable optimization and I am not aware that IVO takes existing register pressure into account (it does limit the number of IVs it creates IIRC). Richard. > Thanks & Regards > Ajit
