On March 30, 2016 2:36:14 PM GMT+02:00, Richard Biener <[email protected]>
wrote:
>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.
Maybe s/overlow/overflow/g while at it..
TIA,
>
>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)))
>>
>>
