On Wed, Jul 22, 2020 at 3:26 AM Kewen.Lin <li...@linux.ibm.com> wrote: > > Hi Richard, > > on 2020/7/21 下午3:57, Richard Biener wrote: > > On Tue, Jul 21, 2020 at 7:52 AM Kewen.Lin <li...@linux.ibm.com> wrote: > >> > >> Hi, > >> > >> This patch is to add the cost modeling for vector with length, > >> it mainly follows what we generate for vector with length in > >> functions vect_set_loop_controls_directly and vect_gen_len > >> at the worst case. > >> > >> For Power, the length is expected to be in bits 0-7 (high bits), > >> we have to model the cost of shifting bits. To allow other targets > >> not suffer this, I used one target hook to describe this extra cost, > >> I'm not sure if it's a correct way. > >> > >> Bootstrapped/regtested on powerpc64le-linux-gnu (P9) with explicit > >> param vect-partial-vector-usage=1. > >> > >> Any comments/suggestions are highly appreciated! > > > > I don't like the introduction of an extra target hook for this. All > > vectorizer cost modeling should ideally go through > > init_cost/add_stmt_cost/finish_cost. If the extra costing is > > not per stmt then either init_cost or finish_cost is appropriate. > > Currently init_cost only gets a struct loop while we should > > probably give it a vec_info * parameter so targets can > > check LOOP_VINFO_USING_PARTIAL_VECTORS_P and friends. > > > > Thanks! Nice, your suggested way looks better. I've removed the hook > and taken care of it in finish_cost. The updated v2 is attached. > > Bootstrapped/regtested again on powerpc64le-linux-gnu (P9) with explicit > param vect-partial-vector-usage=1.
LGTM (with assuming the first larger hunk is mostly re-indenting under LOOP_VINFO_USING_PARTIAL_VECTORS_P). Thanks, Richard. > BR, > Kewen > ----- > gcc/ChangeLog: > > * config/rs6000/rs6000.c (adjust_vect_cost): New function. > (rs6000_finish_cost): Call function adjust_vect_cost. > * tree-vect-loop.c (vect_estimate_min_profitable_iters): Add cost > modeling for vector with length.
