On Mon, 6 Nov 2023, Tamar Christina wrote: > Hi All, > > This sets LOOP_VINFO_EARLY_BREAKS and does some misc changes so the other > patches are self contained. > > Bootstrapped Regtested on aarch64-none-linux-gnu and no issues. > > Ok for master? > > Thanks, > Tamar > > gcc/ChangeLog: > > * tree-vect-loop.cc (vect_analyze_loop_form): Analyse all exits. > (vect_create_loop_vinfo): Set LOOP_VINFO_EARLY_BREAKS. > (vect_transform_loop): Use it. > > --- inline copy of patch -- > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > index > 51a054c5b035ac80dfbbf3b5ba2f6da82fda91f6..f9483eff6e9606e835906fb991f07cd6052491d0 > 100644 > --- a/gcc/tree-vect-loop.cc > +++ b/gcc/tree-vect-loop.cc > @@ -1700,12 +1700,12 @@ vect_compute_single_scalar_iteration_cost > (loop_vec_info loop_vinfo) > loop_vinfo->scalar_costs->finish_cost (nullptr); > } > > - > /* Function vect_analyze_loop_form. > > Verify that certain CFG restrictions hold, including: > - the loop has a pre-header > - - the loop has a single entry and exit > + - the loop has a single entry > + - nested loops can have only a single exit. > - the loop exit condition is simple enough > - the number of iterations can be analyzed, i.e, a countable loop. The > niter could be analyzed under some assumptions. */ > @@ -1841,10 +1841,14 @@ vect_analyze_loop_form (class loop *loop, > vect_loop_form_info *info) > "not vectorized: latch block not empty.\n"); > > /* Make sure the exit is not abnormal. */ > - if (exit_e->flags & EDGE_ABNORMAL) > - return opt_result::failure_at (vect_location, > - "not vectorized:" > - " abnormal loop exit edge.\n"); > + auto_vec<edge> exits = get_loop_exit_edges (loop); > + for (edge e : exits)
Seeing this multiple times, this isn't the most efficient way to iterate over all exits with LOOPS_HAVE_RECORDED_EXITS. Note to myself: fix (add to) the API. > + { > + if (e->flags & EDGE_ABNORMAL) > + return opt_result::failure_at (vect_location, > + "not vectorized:" > + " abnormal loop exit edge.\n"); > + } > > info->conds > = vect_get_loop_niters (loop, exit_e, &info->assumptions, > @@ -1920,6 +1924,10 @@ vect_create_loop_vinfo (class loop *loop, > vec_info_shared *shared, > > LOOP_VINFO_IV_EXIT (loop_vinfo) = info->loop_exit; > > + /* Check to see if we're vectorizing multiple exits. */ > + LOOP_VINFO_EARLY_BREAKS (loop_vinfo) > + = !LOOP_VINFO_LOOP_CONDS (loop_vinfo).is_empty (); > + Seeing this, s/LOOP_VINFO_LOOP_CONDS/LOOP_VINFO_LOOP_EXIT_CONDS/g might be good, if we in future avoid if-conversion in a separate pass we will have other CONDs as well. > if (info->inner_loop_cond) > { > stmt_vec_info inner_loop_cond_info > @@ -11577,7 +11585,7 @@ vect_transform_loop (loop_vec_info loop_vinfo, gimple > *loop_vectorized_call) > /* Make sure there exists a single-predecessor exit bb. Do this before > versioning. */ > edge e = LOOP_VINFO_IV_EXIT (loop_vinfo); > - if (! single_pred_p (e->dest)) > + if (! single_pred_p (e->dest) && !LOOP_VINFO_EARLY_BREAKS (loop_vinfo)) > { > split_loop_exit_edge (e, true); Note this splitting is done to fulfil versioning constraints on CFG update. Do you have test coverage with alias versioning and early breaks? Otherwise OK. Thanks, Richard.