On Wed, May 15, 2019 at 1:20 PM Kewen.Lin <li...@linux.ibm.com> wrote: > > on 2019/5/15 上午11:34, Kewen.Lin wrote: > > > > on 2019/5/15 上午10:40, Bin.Cheng wrote: > >> I wonder if you can factor out generic part into GIMPLE and leave > >> target hook as specific as possible? > >> > > > > Good suggestion! Yes, most of the checks are common as you > > pointed out. I hope the other targets won't have more > > customization needs excepting for that GIMPLE stmt hook > > check. > > > > I am thinking IVOPTs is a best place to factor to? Or > > somewhere to put common GIMPLE query interface? > > > > Or move it into targhooks.cpp as a possible base process > of [target]_predict_doloop_p? The target owner can > decide whether to use generic_predict_doloop_p in its > own target hook. > It seems more flexible and allow them to have a new > implementation for their own targets. Like: > > rs6000_predict_doloop_p: > .... > if (generic_predict_doloop_p(loop)) > ... > > special_target_predict_doloop_p: Hmm, I thought the target hook would not need to take loop parameter after moving generic part into ivopts? Also the moved part would be a local function (calling the new hook on stmt) in ivopts?
Thanks, bin > .... > .... > > > Thanks, > Kewen > > >>> + > >>> + /* Similar to doloop_optimize, check whether iteration count too small > >>> + and not profitable. */ > >>> + HOST_WIDE_INT est_niter = get_estimated_loop_iterations_int (loop); > >>> + if (est_niter == -1) > >>> + est_niter = get_likely_max_loop_iterations_int (loop); > >>> + if (est_niter >= 0 && est_niter < 3) > >> The only probably target dependent is the magic number 3 here. After > >> moving all generic part to ivopts, we can use a macro for the moment, > >> and improve it as a parameter if there are more doloop targets. > > > > The magic number 3 is from function doloop_optimize, not a > > target dependent value. But thanks for your tips with > > macro mechanism! > > > > > > Thanks, > > Kewen > > > >> Overall most of above checks can be moved out of backend, leaving only > >> more specific target hook checking on gimple_stmt? And even that can > >> be made generic to some extend. > >> > >> Thanks, > >> bin > > >
