On Wed, 30 Mar 2016, Jan Hubicka wrote:
> >
> > You are only changing one place in this file.
>
> You are right. I am attaching the updated patch which I am re-testing now.
> >
> > The vectorizer already checks this (albeit indirectly):
> >
> > HOST_WIDE_INT max_niter
> > = max_stmt_executions_int (LOOP_VINFO_LOOP (loop_vinfo));
> > if ((LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
> > && (LOOP_VINFO_INT_NITERS (loop_vinfo) < vectorization_factor))
> > || (max_niter != -1
> > && (unsigned HOST_WIDE_INT) max_niter < vectorization_factor))
> > {
> > if (dump_enabled_p ())
> > dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> > "not vectorized: iteration count smaller than "
> > "vectorization factor.\n");
> > return false;
> > }
>
> Yes, but one tests only vectorization_factor and other min_profitable_estimate
> which probably should be greater than vectorization_factor.
>
> The check above should therefore become redundant. My reading of the code is
> that min_profiltable_estimate is computed after the check above, so it is
> probably an useful shortcut and the message is also bit more informative.
> I updated the later test to use max_niter variable once it is computed.
>
> OK with those changes assuming testing passes?
Ok.
Richard.
> Honza
>
> * tree-ssa-loop-niter.c (idx_infer_loop_bounds): We can't get realistic
> estimates here.
> * tree-ssa-loop-unswitch.c (tree_unswitch_single_loop): Use also
> max_loop_iterations_int.
> (tree_unswitch_outer_loop): Likewise.
> * tree-ssa-loop-ivopts.c (avg_loop_niter): Likewise.
> * tree-vect-loop.c (vect_analyze_loop_2): Likewise.
> Index: tree-ssa-loop-ivopts.c
> ===================================================================
> --- tree-ssa-loop-ivopts.c (revision 234516)
> +++ tree-ssa-loop-ivopts.c (working copy)
> @@ -121,7 +121,11 @@ avg_loop_niter (struct loop *loop)
> {
> HOST_WIDE_INT niter = estimated_stmt_executions_int (loop);
> if (niter == -1)
> - return AVG_LOOP_NITER (loop);
> + {
> + niter = max_stmt_executions_int (loop);
> + if (niter == -1 || niter > AVG_LOOP_NITER (loop))
> + return AVG_LOOP_NITER (loop);
> + }
>
> return niter;
> }
> Index: tree-ssa-loop-niter.c
> ===================================================================
> --- tree-ssa-loop-niter.c (revision 234516)
> +++ tree-ssa-loop-niter.c (working copy)
> @@ -3115,7 +3115,6 @@ idx_infer_loop_bounds (tree base, tree *
> tree low, high, type, next;
> bool sign, upper = true, at_end = false;
> struct loop *loop = data->loop;
> - bool reliable = true;
>
> if (TREE_CODE (base) != ARRAY_REF)
> return true;
> @@ -3187,14 +3186,14 @@ idx_infer_loop_bounds (tree base, tree *
> && tree_int_cst_compare (next, high) <= 0)
> return true;
>
> - /* If access is not executed on every iteration, we must ensure that
> overlow may
> - not make the access valid later. */
> + /* If access is not executed on every iteration, we must ensure that
> overlow
> + may not make the access valid later. */
> if (!dominated_by_p (CDI_DOMINATORS, loop->latch, gimple_bb (data->stmt))
> && scev_probably_wraps_p (initial_condition_in_loop_num (ev,
> loop->num),
> step, data->stmt, loop, true))
> - reliable = false;
> + upper = false;
>
> - record_nonwrapping_iv (loop, init, step, data->stmt, low, high, reliable,
> upper);
> + record_nonwrapping_iv (loop, init, step, data->stmt, low, high, false,
> upper);
> return true;
> }
>
> Index: tree-ssa-loop-unswitch.c
> ===================================================================
> --- tree-ssa-loop-unswitch.c (revision 234516)
> +++ tree-ssa-loop-unswitch.c (working copy)
> @@ -223,6 +223,8 @@ tree_unswitch_single_loop (struct loop *
> /* If the loop is not expected to iterate, there is no need
> for unswitching. */
> iterations = estimated_loop_iterations_int (loop);
> + if (iterations < 0)
> + iterations = max_loop_iterations_int (loop);
> if (iterations >= 0 && iterations <= 1)
> {
> if (dump_file && (dump_flags & TDF_DETAILS))
> @@ -439,6 +441,8 @@ tree_unswitch_outer_loop (struct loop *l
> /* If the loop is not expected to iterate, there is no need
> for unswitching. */
> iterations = estimated_loop_iterations_int (loop);
> + if (iterations < 0)
> + iterations = max_loop_iterations_int (loop);
> if (iterations >= 0 && iterations <= 1)
> {
> if (dump_file && (dump_flags & TDF_DETAILS))
> Index: tree-vect-loop.c
> ===================================================================
> --- tree-vect-loop.c (revision 234516)
> +++ tree-vect-loop.c (working copy)
> @@ -2063,6 +2063,8 @@ start_over:
>
> estimated_niter
> = estimated_stmt_executions_int (LOOP_VINFO_LOOP (loop_vinfo));
> + if (estimated_niter != -1)
> + estimated_niter = max_niter;
> if (estimated_niter != -1
> && ((unsigned HOST_WIDE_INT) estimated_niter
> <= MAX (th, (unsigned)min_profitable_estimate)))
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
