[PATCH,1/2] Extended if-conversion for loops marked with pragma omp simd.
Yuri Rumyantsev
ysrumyan@gmail.com
Tue Oct 21 14:01:00 GMT 2014
Richard,
I saw the sources of these functions, but I can't understand why I
should use something else? Note that all predicate computations are
located in basic blocks ( by design of if-conv) and there is special
function that put these computations in bb
(insert_gimplified_predicates). Edge contains only predicate not its
computations. New function - find_insertion_point() does very simple
search - it finds out the latest (in current bb) operand def-stmt of
predicates taken from all incoming edges.
In original algorithm the predicate of non-critical edge is taken to
perform phi-node predication since for critical edge it does not work
properly.
My question is: does your comments mean that I should re-design my extensions?
Thanks.
Yuri.
BTW Jeff did initial review of my changes related to predicate
computation for join blocks. I presented him updated patch with
test-case and some minor changes in patch. But still did not get any
feedback on it. Could you please take a look also on it?
2014-10-21 17:38 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
> On Tue, Oct 21, 2014 at 3:20 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>> Richard,
>>
>> Yes, This patch does not make sense since phi node predication for bb
>> with critical incoming edges only performs another function which is
>> absent (predicate_extended_scalar_phi).
>>
>> BTW I see that commit_edge_insertions() is used for rtx instructions
>> only but you propose to use it for tree also.
>> Did I miss something?
>
> Ah, it's gsi_commit_edge_inserts () (or gsi_commit_one_edge_insert
> if you want easy access to the newly created basic block to push
> the predicate to - see gsi_commit_edge_inserts implementation).
>
> Richard.
>
>> Thanks ahead.
>>
>>
>> 2014-10-21 16:44 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
>>> On Tue, Oct 21, 2014 at 2:25 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>> Richard,
>>>>
>>>> I did some changes in patch and ChangeLog to mark that support for
>>>> if-convert of blocks with only critical incoming edges will be added
>>>> in the future (more precise in patch.4).
>>>
>>> But the same reasoning applies to this version of the patch when
>>> flag_force_vectorize is true!? (insertion point and invalid SSA form)
>>>
>>> Which means the patch doesn't make sense in isolation?
>>>
>>> Btw, I think for the case you should simply do gsi_insert_on_edge ()
>>> and commit_edge_insertions () before the call to combine_blocks
>>> (pushing the edge predicate to the newly created block).
>>>
>>> Richard.
>>>
>>>> Could you please review it.
>>>>
>>>> Thanks.
>>>>
>>>> ChangeLog:
>>>>
>>>> 2014-10-21 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>
>>>> (flag_force_vectorize): New variable.
>>>> (edge_predicate): New function.
>>>> (set_edge_predicate): New function.
>>>> (add_to_dst_predicate_list): Conditionally invoke add_to_predicate_list
>>>> if destination block of edge is not always executed. Set-up predicate
>>>> for critical edge.
>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>> if FLAG_FORCE_VECTORIZE was set-up.
>>>> (ifcvt_can_use_mask_load_store): Use FLAG_FORCE_VECTORIZE.
>>>> (if_convertible_stmt_p): Fix up pre-function comments.
>>>> (all_preds_critical_p): New function.
>>>> (if_convertible_bb_p): Use call of all_preds_critical_p
>>>> to reject temporarily block if-conversion with incoming critical edges
>>>> if FLAG_FORCE_VECTORIZE was not set-up. This restriction will be deleted
>>>> after adding support for extended predication.
>>>> (predicate_bbs): Skip loop exit block also.Invoke build2_loc
>>>> to compute predicate instead of fold_build2_loc.
>>>> Add zeroing of edge 'aux' field.
>>>> (find_phi_replacement_condition): Extend function interface:
>>>> it returns NULL if given phi node must be handled by means of
>>>> extended phi node predication. If number of predecessors of phi-block
>>>> is equal 2 and at least one incoming edge is not critical original
>>>> algorithm is used.
>>>> (tree_if_conversion): Temporarily set-up FLAG_FORCE_VECTORIZE to false.
>>>> Nullify 'aux' field of edges for blocks with two successors.
>>>>
>>>> 2014-10-20 17:55 GMT+04:00 Yuri Rumyantsev <ysrumyan@gmail.com>:
>>>>> Richard,
>>>>>
>>>>> Thanks for your answer!
>>>>>
>>>>> In current implementation phi node conversion assume that one of
>>>>> incoming edge to bb containing given phi has at least one non-critical
>>>>> edge and choose it to insert predicated code. But if we choose
>>>>> critical edge we need to determine insert point and insertion
>>>>> direction (before/after) since in other case we can get invalid ssa
>>>>> form (use before def). This is done by my new function which is not in
>>>>> current patch ( I will present this patch later). SO I assume that we
>>>>> need to leave this patch as it is to not introduce new bugs.
>>>>>
>>>>> Thanks.
>>>>> Yuri.
>>>>>
>>>>> 2014-10-20 12:00 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
>>>>>> On Fri, Oct 17, 2014 at 4:09 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>>>> Richard,
>>>>>>>
>>>>>>> I reworked the patch as you proposed, but I didn't understand what
>>>>>>> did you mean by:
>>>>>>>
>>>>>>>>So please rework the patch so critical edges are always handled
>>>>>>>>correctly.
>>>>>>>
>>>>>>> In current patch flag_force_vectorize is used (1) to reject phi nodes
>>>>>>> with more than 2 arguments; (2) to reject basic blocks with only
>>>>>>> critical incoming edges since support for extended predication of phi
>>>>>>> nodes will be in next patch.
>>>>>>
>>>>>> I mean that (2) should not be rejected dependent on flag_force_vectorize.
>>>>>> It was rejected because if-cvt couldn't handle it correctly before but with
>>>>>> this patch this is fixed. I see no reason to still reject this then even
>>>>>> for !flag_force_vectorize.
>>>>>>
>>>>>> Rejecting PHIs with more than two arguments with flag_force_vectorize
>>>>>> is ok.
>>>>>>
>>>>>> Richard.
>>>>>>
>>>>>>> Could you please clarify your statement.
>>>>>>>
>>>>>>> I attached modified patch.
>>>>>>>
>>>>>>> ChangeLog:
>>>>>>>
>>>>>>> 2014-10-17 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>
>>>>>>> (flag_force_vectorize): New variable.
>>>>>>> (edge_predicate): New function.
>>>>>>> (set_edge_predicate): New function.
>>>>>>> (add_to_dst_predicate_list): Conditionally invoke add_to_predicate_list
>>>>>>> if destination block of edge is not always executed. Set-up predicate
>>>>>>> for critical edge.
>>>>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>>>>> if FLAG_FORCE_VECTORIZE was set-up.
>>>>>>> (ifcvt_can_use_mask_load_store): Use FLAG_FORCE_VECTORIZE.
>>>>>>> (if_convertible_stmt_p): Fix up pre-function comments.
>>>>>>> (all_edges_are_critical): New function.
>>>>>>> (if_convertible_bb_p): Use call of all_preds_critical_p
>>>>>>> to reject block if-conversion with incoming critical edges only if
>>>>>>> FLAG_FORCE_VECTORIZE was not set-up.
>>>>>>> (predicate_bbs): Skip loop exit block also.Invoke build2_loc
>>>>>>> to compute predicate instead of fold_build2_loc.
>>>>>>> Add zeroing of edge 'aux' field.
>>>>>>> (find_phi_replacement_condition): Extend function interface:
>>>>>>> it returns NULL if given phi node must be handled by means of
>>>>>>> extended phi node predication. If number of predecessors of phi-block
>>>>>>> is equal 2 and atleast one incoming edge is not critical original
>>>>>>> algorithm is used.
>>>>>>> (tree_if_conversion): Temporary set-up FLAG_FORCE_VECTORIZE to false.
>>>>>>> Nullify 'aux' field of edges for blocks with two successors.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> 2014-10-17 13:09 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
>>>>>>>> On Thu, Oct 16, 2014 at 5:42 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>>>>>> Richard,
>>>>>>>>>
>>>>>>>>> Here is reduced patch as you requested. All your remarks have been fixed.
>>>>>>>>> Could you please look at it ( I have already sent the patch with
>>>>>>>>> changes in add_to_predicate_list for review).
>>>>>>>>
>>>>>>>> + if (dump_file && (dump_flags & TDF_DETAILS))
>>>>>>>> + fprintf (dump_file, "More than two phi node args.\n");
>>>>>>>> + return false;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + }
>>>>>>>>
>>>>>>>> Excess vertical space.
>>>>>>>>
>>>>>>>>
>>>>>>>> +/* Assumes that BB has more than 2 predecessors.
>>>>>>>>
>>>>>>>> More than 1 predecessor?
>>>>>>>>
>>>>>>>> + Returns false if at least one successor is not on critical edge
>>>>>>>> + and true otherwise. */
>>>>>>>> +
>>>>>>>> +static inline bool
>>>>>>>> +all_edges_are_critical (basic_block bb)
>>>>>>>> +{
>>>>>>>>
>>>>>>>> "all_preds_critical_p" would be a better name
>>>>>>>>
>>>>>>>> + if (EDGE_COUNT (bb->preds) > 2)
>>>>>>>> + {
>>>>>>>> + if (!flag_force_vectorize)
>>>>>>>> + return false;
>>>>>>>> + }
>>>>>>>>
>>>>>>>> as I said in the last review I don't think we should restrict edge
>>>>>>>> predicates to flag_force_vectorize. At least I can't see how
>>>>>>>> if-conversion is magically more expensive for that case?
>>>>>>>>
>>>>>>>> So please rework the patch so critical edges are always handled
>>>>>>>> correctly.
>>>>>>>>
>>>>>>>> Ok with that and the above suggested changes.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Richard.
>>>>>>>>
>>>>>>>>
>>>>>>>>> Thanks.
>>>>>>>>> Yuri.
>>>>>>>>> ChangeLog
>>>>>>>>> 2014-10-16 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>>>
>>>>>>>>> (flag_force_vectorize): New variable.
>>>>>>>>> (edge_predicate): New function.
>>>>>>>>> (set_edge_predicate): New function.
>>>>>>>>> (add_to_dst_predicate_list): Conditionally invoke add_to_predicate_list
>>>>>>>>> if destination block of edge is not always executed. Set-up predicate
>>>>>>>>> for critical edge.
>>>>>>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>>>>>>> if FLAG_FORCE_VECTORIZE was set-up.
>>>>>>>>> (ifcvt_can_use_mask_load_store): Use FLAG_FORCE_VECTORIZE.
>>>>>>>>> (if_convertible_stmt_p): Fix up pre-function comments.
>>>>>>>>> (all_edges_are_critical): New function.
>>>>>>>>> (if_convertible_bb_p): Allow bb has more than two predecessors if
>>>>>>>>> FLAG_FORCE_VECTORIZE was set-up. Use call of all_edges_are_critical
>>>>>>>>> to reject block if-conversion with incoming critical edges only if
>>>>>>>>> FLAG_FORCE_VECTORIZE was not set-up.
>>>>>>>>> (predicate_bbs): Skip loop exit block also.Invoke build2_loc
>>>>>>>>> to compute predicate instead of fold_build2_loc.
>>>>>>>>> Add zeroing of edge 'aux' field.
>>>>>>>>> (find_phi_replacement_condition): Extend function interface:
>>>>>>>>> it returns NULL if given phi node must be handled by means of
>>>>>>>>> extended phi node predication. If number of predecessors of phi-block
>>>>>>>>> is equal 2 and atleast one incoming edge is not critical original
>>>>>>>>> algorithm is used.
>>>>>>>>> (tree_if_conversion): Temporary set-up FLAG_FORCE_VECTORIZE to false.
>>>>>>>>> Nullify 'aux' field of edges for blocks with two successors.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> 2014-10-15 13:50 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
>>>>>>>>>> On Mon, Oct 13, 2014 at 11:38 AM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>>>>>>>> Richard,
>>>>>>>>>>>
>>>>>>>>>>> Here is updated patch (part1) for extended if conversion.
>>>>>>>>>>>
>>>>>>>>>>> Second part of patch will be sent later.
>>>>>>>>>>
>>>>>>>>>> Ok, I'm starting to look at this. I'd still like you to split things up
>>>>>>>>>> more.
>>>>>>>>>>
>>>>>>>>>> static inline void
>>>>>>>>>> add_to_predicate_list (struct loop *loop, basic_block bb, tree nc)
>>>>>>>>>> {
>>>>>>>>>> ...
>>>>>>>>>>
>>>>>>>>>> + /* We use notion of cd equivalence to get simplier predicate for
>>>>>>>>>> + join block, e.g. if join block has 2 predecessors with predicates
>>>>>>>>>> + p1 & p2 and p1 & !p2, we'd like to get p1 for it instead of
>>>>>>>>>> + p1 & p2 | p1 & !p2. */
>>>>>>>>>> + if (dom_bb != loop->header
>>>>>>>>>> + && get_immediate_dominator (CDI_POST_DOMINATORS, dom_bb) == bb)
>>>>>>>>>> + {
>>>>>>>>>> + gcc_assert (flow_bb_inside_loop_p (loop, dom_bb));
>>>>>>>>>> + bc = bb_predicate (dom_bb);
>>>>>>>>>> + gcc_assert (!is_true_predicate (bc));
>>>>>>>>>>
>>>>>>>>>> these changes look worthwhile even for !flag_force_vectorize. So please
>>>>>>>>>> split the change to add_to_predicate_list out and compute post-dominators
>>>>>>>>>> unconditionally. Note that you should call free_dominance_info
>>>>>>>>>> (CDI_POST_DOMINATORS) at the end of if-conversion.
>>>>>>>>>>
>>>>>>>>>> + if (!dominated_by_p (CDI_DOMINATORS, loop->latch, e->dest))
>>>>>>>>>> + add_to_predicate_list (loop, e->dest, cond);
>>>>>>>>>> +
>>>>>>>>>> + /* If edge E is critical save predicate on it. */
>>>>>>>>>> + if (EDGE_COUNT (e->dest->preds) >= 2)
>>>>>>>>>> + set_edge_predicate (e, cond);
>>>>>>>>>>
>>>>>>>>>> how do we know the edge is critical by this simple check? Why not
>>>>>>>>>> simply always save edge predicates (well, you kind of do but omit
>>>>>>>>>> the case where e->src dominates e->dest).
>>>>>>>>>>
>>>>>>>>>> Btw, you can rely on edge->aux being NULL at the start of the
>>>>>>>>>> pass but need to clear it at the end (best use clear_aux_for_edges ()
>>>>>>>>>> for that). So stuff like
>>>>>>>>>>
>>>>>>>>>> + extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
>>>>>>>>>> + if (flag_force_vectorize)
>>>>>>>>>> + true_edge->aux = false_edge->aux = NULL;
>>>>>>>>>>
>>>>>>>>>> shouldn't be necessary.
>>>>>>>>>>
>>>>>>>>>> I think the edge predicate handling should also be unconditionally
>>>>>>>>>> and not depend on flag_force_vectorize.
>>>>>>>>>>
>>>>>>>>>> + /* The loop latch and loop exit block are always executed and
>>>>>>>>>> + have no extra conditions to be processed: skip them. */
>>>>>>>>>> + if (bb == loop->latch
>>>>>>>>>> + || bb_with_exit_edge_p (loop, bb))
>>>>>>>>>>
>>>>>>>>>> I don't think the edge stuff is true - given you still only reset the
>>>>>>>>>> loop->latch bb predicate the change looks broken.
>>>>>>>>>>
>>>>>>>>>> + /* Fold_build2 can produce bool conversion which is not
>>>>>>>>>> + supported by vectorizer, so re-build it without folding.
>>>>>>>>>> + For example, such conversion is generated for sequence:
>>>>>>>>>> + _Bool _7, _8, _9;
>>>>>>>>>> + _7 = _6 != 13; _8 = _6 != 0; _9 = _8 & _9;
>>>>>>>>>> + if (_9 != 0) --> (bool)_9. */
>>>>>>>>>> +
>>>>>>>>>> + if (CONVERT_EXPR_P (c)
>>>>>>>>>> + && TREE_CODE_CLASS (code) == tcc_comparison)
>>>>>>>>>>
>>>>>>>>>> I think you should simply use canonicalize_cond_expr_cond on the
>>>>>>>>>> folding result. Or rather _not_ fold at all - we are taking the
>>>>>>>>>> operands from the GIMPLE condition unmodified after all.
>>>>>>>>>>
>>>>>>>>>> - add_to_dst_predicate_list (loop, false_edge,
>>>>>>>>>> - unshare_expr (cond), c2);
>>>>>>>>>> + add_to_dst_predicate_list (loop, false_edge, unshare_expr (cond),
>>>>>>>>>> + unshare_expr (c2));
>>>>>>>>>>
>>>>>>>>>> why is it necessary to unshare c2?
>>>>>>>>>>
>>>>>>>>>> Please split out the PHI-with-multi-arg handling (I have not looked at
>>>>>>>>>> that in detail).
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Richard.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> Changelog.
>>>>>>>>>>>
>>>>>>>>>>> 2014-10-13 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>>>>>
>>>>>>>>>>> * tree-if-conv.c (cgraph.h): Add include file to detect function clone.
>>>>>>>>>>> (flag_force_vectorize): New variable.
>>>>>>>>>>> (edge_predicate): New function.
>>>>>>>>>>> (set_edge_predicate): New function.
>>>>>>>>>>> (add_to_predicate_list): Check unconditionally that bb is always
>>>>>>>>>>> executed to early exit. Use predicate of cd-equivalent block
>>>>>>>>>>> for join blocks if it exists.
>>>>>>>>>>> (add_to_dst_predicate_list): Invoke add_to_predicate_list if
>>>>>>>>>>> destination block of edge is not always executed. Set-up predicate
>>>>>>>>>>> for critical edge.
>>>>>>>>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>>>>>>>>> if FLAG_FORCE_VECTORIZE was set-up.
>>>>>>>>>>> (ifcvt_can_use_mask_load_store): Use FLAG_FORCE_VECTORIZE.
>>>>>>>>>>> (if_convertible_stmt_p): Fix up pre-function comments.
>>>>>>>>>>> (all_edges_are_critical): New function.
>>>>>>>>>>> (if_convertible_bb_p): Allow bb has more than two predecessors if
>>>>>>>>>>> FLAG_FORCE_VECTORIZE was set-up. Use call of all_edges_are_critical
>>>>>>>>>>> to reject block if-conversion with incoming critical edges only if
>>>>>>>>>>> FLAG_FORCE_VECTORIZE was not set-up.
>>>>>>>>>>> (predicate_bbs): Skip loop exit block also. Add check that if
>>>>>>>>>>> fold_build2 produces bool conversion, recompute predicate using
>>>>>>>>>>> build2_loc. Add zeroing of edge 'aux' field under FLAG_FORCE_VECTORIZE.
>>>>>>>>>>> (if_convertible_loop_p_1): Recompute POST_DOMINATOR tree if
>>>>>>>>>>> FLAG_FORCE_VECTORIZE was set-up to calculate cd equivalent bb's.
>>>>>>>>>>> (find_phi_replacement_condition): Extend function interface:
>>>>>>>>>>> it returns NULL if given phi node must be handled by means of
>>>>>>>>>>> extended phi node predication. If number of predecessors of phi-block
>>>>>>>>>>> is equal 2 and atleast one incoming edge is not critical original
>>>>>>>>>>> algorithm is used.
>>>>>>>>>>> (get_predicate_for_edge): New function.
>>>>>>>>>>> (find_insertion_point): New function.
>>>>>>>>>>> (predicate_arbitrary_scalar_phi): New function.
>>>>>>>>>>> (predicate_all_scalar_phis): Introduce new variable BEFORE.
>>>>>>>>>>> Invoke find_insertion_point to initialize gsi and
>>>>>>>>>>> predicate_arbitrary_scalar_phi if TRUE_BB is NULL - it signals
>>>>>>>>>>> that extended predication must be applied).
>>>>>>>>>>> (insert_gimplified_predicates): Add test for non-predicated basic
>>>>>>>>>>> blocks that there are no gimplified statements to insert. Insert
>>>>>>>>>>> predicates at the block begining for extended if-conversion.
>>>>>>>>>>> (tree_if_conversion): Initialize flag_force_vectorize from current
>>>>>>>>>>> loop or outer loop (to support pragma omp declare).Do loop versioning
>>>>>>>>>>> for innermost loop marked with pragma omp simd and
>>>>>>>>>>> FLAG_TREE_LOOP_IF_CONVERT was not sett-up. Nullify 'aux' field of edges
>>>>>>>>>>> for blocks with two successors.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> 2014-09-22 12:28 GMT+04:00 Yuri Rumyantsev <ysrumyan@gmail.com>:
>>>>>>>>>>>> Richard,
>>>>>>>>>>>>
>>>>>>>>>>>> here is reduced patch (part.1) which was reduced almost twice.
>>>>>>>>>>>> Let's me also answer on your comments.
>>>>>>>>>>>>
>>>>>>>>>>>> 1. I really use edge field 'aux' to keep predicate for critical edges.
>>>>>>>>>>>> My previous code was not correct and now it looks like:
>>>>>>>>>>>>
>>>>>>>>>>>> if (EDGE_COUNT (b->succs) == 1 || EDGE_COUNT (e->dest->preds) == 1)
>>>>>>>>>>>> /* Edge E is not critical, use predicate of edge source bb. */
>>>>>>>>>>>> c = bb_predicate (b);
>>>>>>>>>>>> else
>>>>>>>>>>>> /* Edge E is critical and its aux field contains predicate. */
>>>>>>>>>>>> c = edge_predicate (e);
>>>>>>>>>>>>
>>>>>>>>>>>> 2. I completely delete all code related to creation of conditional
>>>>>>>>>>>> expressions and completely rely on bool pattern recognition in
>>>>>>>>>>>> vectorizer. But we need to delete all dead predicate computations
>>>>>>>>>>>> which are not used since they prevent vectorization. I will add this
>>>>>>>>>>>> local-dce function in next patch.
>>>>>>>>>>>> 3. I also did not include in this patch recognition of general
>>>>>>>>>>>> phi-nodes with two arguments only for which conversion of conditional
>>>>>>>>>>>> scalar reduction can be applied also.
>>>>>>>>>>>> Note that all these changes are applied for loop marked with pragma
>>>>>>>>>>>> omp simd only.
>>>>>>>>>>>>
>>>>>>>>>>>> 2014-09-22 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>>>>>>
>>>>>>>>>>>> * tree-if-conv.c (cgraph.h): Add include file to detect function clone.
>>>>>>>>>>>> (flag_force_vectorize): New variable.
>>>>>>>>>>>> (edge_predicate): New function.
>>>>>>>>>>>> (set_edge_predicate): New function.
>>>>>>>>>>>> (convert_name_to_cmp): New function.
>>>>>>>>>>>> (add_to_predicate_list): Check unconditionally that bb is always
>>>>>>>>>>>> executed to early exit. Use predicate of cd-equivalent block
>>>>>>>>>>>> for join blocks if it exists.
>>>>>>>>>>>> (add_to_dst_predicate_list): Invoke add_to_predicate_list if
>>>>>>>>>>>> destination block of edge is not always executed. Set-up predicate
>>>>>>>>>>>> for critical edge.
>>>>>>>>>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>>>>>>>>>> if FLAG_FORCE_VECTORIZE was set-up.
>>>>>>>>>>>> (ifcvt_can_use_mask_load_store): Use FLAG_FORCE_VECTORIZE.
>>>>>>>>>>>> (if_convertible_stmt_p): Fix up pre-function comments.
>>>>>>>>>>>> (all_edges_are_critical): New function.
>>>>>>>>>>>> (if_convertible_bb_p): Allow bb has more than two predecessors if
>>>>>>>>>>>> FLAG_FORCE_VECTORIZE was set-up. Use call of all_edges_are_critical
>>>>>>>>>>>> to reject block if-conversion with incoming critical edges only if
>>>>>>>>>>>> FLAG_FORCE_VECTORIZE was not set-up.
>>>>>>>>>>>> (predicate_bbs): Skip loop exit block also. Add check that if
>>>>>>>>>>>> fold_build2 produces bool conversion, recompute predicate using
>>>>>>>>>>>> build2_loc. Add zeroing of edge 'aux' field under FLAG_FORCE_VECTORIZE.
>>>>>>>>>>>> (if_convertible_loop_p_1): Recompute POST_DOMINATOR tree if
>>>>>>>>>>>> FLAG_FORCE_VECTORIZE was set-up to calculate cd equivalent bb's.
>>>>>>>>>>>> (find_phi_replacement_condition): Extend function interface:
>>>>>>>>>>>> it returns NULL if given phi node must be handled by means of
>>>>>>>>>>>> extended phi node predication. If number of predecessors of phi-block
>>>>>>>>>>>> is equal 2 and atleast one incoming edge is not critical original
>>>>>>>>>>>> algorithm is used.
>>>>>>>>>>>> (get_predicate_for_edge): New function.
>>>>>>>>>>>> (find_insertion_point): New function.
>>>>>>>>>>>> (predicate_arbitrary_scalar_phi): New function.
>>>>>>>>>>>> (predicate_all_scalar_phis): Introduce new variable BEFORE.
>>>>>>>>>>>> Invoke find_insertion_point to initialize gsi and
>>>>>>>>>>>> predicate_arbitrary_scalar_phi if TRUE_BB is NULL - it signals
>>>>>>>>>>>> that extended predication must be applied).
>>>>>>>>>>>> (insert_gimplified_predicates): Add test for non-predicated basic
>>>>>>>>>>>> blocks that there are no gimplified statements to insert. Insert
>>>>>>>>>>>> predicates at the block begining for extended if-conversion.
>>>>>>>>>>>> (tree_if_conversion): Initialize flag_force_vectorize from current
>>>>>>>>>>>> loop or outer loop (to support pragma omp declare).Do loop versioning
>>>>>>>>>>>> for innermost loop marked with pragma omp simd and
>>>>>>>>>>>> FLAG_TREE_LOOP_IF_CONVERT was not sett-up. Nullify 'aux' field of edges
>>>>>>>>>>>> for blocks with two successors.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> 2014-09-08 17:10 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
>>>>>>>>>>>>> On Fri, Aug 15, 2014 at 2:02 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>>>>>>>>>>> Richard!
>>>>>>>>>>>>>> Here is updated patch with the following changes:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> 1. Any restrictions on phi-function were eliminated for extended conversion.
>>>>>>>>>>>>>> 2. Put predicate for critical edges to 'aux' field of edge, i.e.
>>>>>>>>>>>>>> negate_predicate was deleted.
>>>>>>>>>>>>>> 3. Deleted splitting of critical edges, i.e. both outgoing edges can
>>>>>>>>>>>>>> be critical.
>>>>>>>>>>>>>> 4. Use notion of cd-equivalence to set-up predicate for join basic
>>>>>>>>>>>>>> blocks to simplify it.
>>>>>>>>>>>>>> 5. I decided to not design pre-pass since it will lead generating
>>>>>>>>>>>>>> chain of cond expressions for phi-node if conversion, whereas for phi
>>>>>>>>>>>>>> of kind
>>>>>>>>>>>>>> x = PHI <1(2), 1(3), 2(4)>
>>>>>>>>>>>>>> only one cond expression is required and this is considered as simple
>>>>>>>>>>>>>> optimization for arbitrary phi-function. More precise,
>>>>>>>>>>>>>> if phi-function have only two different arguments and one of them has
>>>>>>>>>>>>>> single occurrence, if- conversion is performed as if phi have only 2
>>>>>>>>>>>>>> arguments.
>>>>>>>>>>>>>> For arbitrary phi function a chain of cond expressions is produced.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Updated patch is attached.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Any comments will be appreciated.
>>>>>>>>>>>>>
>>>>>>>>>>>>> The patch is still very big and does multiple things at once which makes
>>>>>>>>>>>>> it hard to review.
>>>>>>>>>>>>>
>>>>>>>>>>>>> In addition to that it changes function singatures without updating
>>>>>>>>>>>>> the function comments. For example what is the convert_bool
>>>>>>>>>>>>> argument doing to add_to_dst_predicate_list? Why do we need
>>>>>>>>>>>>> all this added logic.
>>>>>>>>>>>>>
>>>>>>>>>>>>> You duplicate operand_equal_for_phi_arg_p.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I think the code handling PHIs with more than two operands but
>>>>>>>>>>>>> only two unequal operands is useful generally, so that's an obvious
>>>>>>>>>>>>> candidate for splitting out into a separate patch.
>>>>>>>>>>>>>
>>>>>>>>>>>>> + CONVERT_BOOL argument was added to convert bool predicate computations
>>>>>>>>>>>>> + which is not supported by vectorizer to int type through creating of
>>>>>>>>>>>>> + conditional expressions. */
>>>>>>>>>>>>>
>>>>>>>>>>>>> Example? The vectorizer has patterns for bool predicate computations.
>>>>>>>>>>>>> This seems to be another feature that needs splitting out.
>>>>>>>>>>>>>
>>>>>>>>>>>>> The way you get around the critical edge parts looks awkward to me.
>>>>>>>>>>>>> Please either do _all_ predicates as edge predicates or simply
>>>>>>>>>>>>> split critical edges (of the respective loop body).
>>>>>>>>>>>>>
>>>>>>>>>>>>> I still think that an utility doing same PHI arg merging by introducing
>>>>>>>>>>>>> forwarder blocks would be nicer to have.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I'd restructure the main tree_if_conversion function to apply these
>>>>>>>>>>>>> CFG pre-transforms when we are going to version the loop
>>>>>>>>>>>>> for if conversion (eventually transitioning to always doing that).
>>>>>>>>>>>>>
>>>>>>>>>>>>> So - please split up the patch. It's way too big.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>> Richard.
>>>>>>>>>>>>>
>>>>>>>>>>>>>> 2014-08-15 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> * tree-if-conv.c (cgraph.h): Add include file to detect function clone.
>>>>>>>>>>>>>> (flag_force_vectorize): New variable.
>>>>>>>>>>>>>> (edge_predicate): New function.
>>>>>>>>>>>>>> (set_edge_predicate): New function.
>>>>>>>>>>>>>> (add_stmt_to_bb_predicate_gimplified_stmts): New function.
>>>>>>>>>>>>>> (init_bb_predicate): Add initialization of negate_predicate field.
>>>>>>>>>>>>>> (reset_bb_predicate): Reset negate_predicate to NULL_TREE.
>>>>>>>>>>>>>> (convert_name_to_cmp): New function.
>>>>>>>>>>>>>> (get_type_for_cond): New function.
>>>>>>>>>>>>>> (convert_bool_predicate): New function.
>>>>>>>>>>>>>> (predicate_disjunction): New function.
>>>>>>>>>>>>>> (predicate_conjunction): New function.
>>>>>>>>>>>>>> (add_to_predicate_list): Add convert_bool argument.
>>>>>>>>>>>>>> Use predicate of cd-equivalent block if convert_bool is true and
>>>>>>>>>>>>>> such bb exists; save it in static variable for further possible use.
>>>>>>>>>>>>>> Add call of predicate_disjunction if convert_bool argument is true.
>>>>>>>>>>>>>> (add_to_dst_predicate_list): Add convert_bool argument.
>>>>>>>>>>>>>> Add early function exit if edge target block is always executed.
>>>>>>>>>>>>>> Add call of predicate_conjunction if convert_bool argument is true.
>>>>>>>>>>>>>> Pass convert_bool argument for add_to_predicate_list.
>>>>>>>>>>>>>> Set-up predicate for crritical edge if convert_bool is true.
>>>>>>>>>>>>>> (equal_phi_args): New function.
>>>>>>>>>>>>>> (phi_has_two_different_args): New function.
>>>>>>>>>>>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>>>>>>>>>>>> if flag_force_vectorize wa set-up.
>>>>>>>>>>>>>> (ifcvt_can_use_mask_load_store): Add test on flag_force_vectorize.
>>>>>>>>>>>>>> (if_convertible_stmt_p): Allow calls of function clones if
>>>>>>>>>>>>>> flag_force_vectorize was set-up.
>>>>>>>>>>>>>> (all_edges_are_critical): New function.
>>>>>>>>>>>>>> (if_convertible_bb_p): Allow bb has more than two predecessors if
>>>>>>>>>>>>>> flag_force_vectorize was set-up. Use call of all_edges_are_critical
>>>>>>>>>>>>>> to reject block if-conversion with imcoming critical edges only if
>>>>>>>>>>>>>> flag_force_vectorize was not set-up.
>>>>>>>>>>>>>> (walk_cond_tree): New function.
>>>>>>>>>>>>>> (vect_bool_pattern_is_applicable): New function.
>>>>>>>>>>>>>> (predicate_bbs): Add convert_bool argument which is used to transform
>>>>>>>>>>>>>> comparison expressions of boolean type into conditional expressions
>>>>>>>>>>>>>> with integral operands. If convert_bool argument was set-up and
>>>>>>>>>>>>>> vect bool pattern can be appied perform the following transformation:
>>>>>>>>>>>>>> (bool) x != 0 --> y = (int) x; x != 0;
>>>>>>>>>>>>>> Add check that if fold_build2 produces bool conversion if convert_bool
>>>>>>>>>>>>>> was set-up, recompute predicate using build2_loc. Additional argument
>>>>>>>>>>>>>> 'convert_bool" is passed to add_to_dst_predicate_list and
>>>>>>>>>>>>>> add_to_predicate_list.
>>>>>>>>>>>>>> (if_convertible_loop_p_1): Recompute POST_DOMINATOR tree if
>>>>>>>>>>>>>> flag_force_vectorize was set-up to calculate cd equivalent bb's.
>>>>>>>>>>>>>> Call predicate_bbs with additional argument equal to false.
>>>>>>>>>>>>>> (find_phi_replacement_condition): Extend function interface:
>>>>>>>>>>>>>> it returns NULL if given phi node must be handled by means of
>>>>>>>>>>>>>> extended phi node predication. If number of predecessors of phi-block
>>>>>>>>>>>>>> is equal 2 and atleast one incoming edge is not critical original
>>>>>>>>>>>>>> algorithm is used.
>>>>>>>>>>>>>> (is_cond_scalar_reduction): Add 'extended' argument which signals that
>>>>>>>>>>>>>> phi arguments must be evaluated through phi_has_two_different_args.
>>>>>>>>>>>>>> (predicate_scalar_phi): Add invoсation of convert_name_to_cmp if cond
>>>>>>>>>>>>>> is SSA_NAME. Add 'false' argument to call of is_cond_scalar_reduction.
>>>>>>>>>>>>>> (get_predicate_for_edge): New function.
>>>>>>>>>>>>>> (find_insertion_point): New function.
>>>>>>>>>>>>>> (predicate_arbitrary_phi): New function.
>>>>>>>>>>>>>> (predicate_extended_scalar_phi): New function.
>>>>>>>>>>>>>> (predicate_all_scalar_phis): Add code to set-up gimple statement
>>>>>>>>>>>>>> iterator for predication of extended scalar phi's for insertion.
>>>>>>>>>>>>>> (insert_gimplified_predicates): Add test for non-predicated basic
>>>>>>>>>>>>>> blocks that there are no gimplified statements to insert. Insert
>>>>>>>>>>>>>> predicates at the block begining for extended if-conversion.
>>>>>>>>>>>>>> (predicate_mem_writes): Invoke convert_name_to_cmp for extended
>>>>>>>>>>>>>> predication to build mask.
>>>>>>>>>>>>>> (combine_blocks): Pass flag_force_vectorize to predicate_bbs.
>>>>>>>>>>>>>> (tree_if_conversion): Initialize flag_force_vectorize from current
>>>>>>>>>>>>>> loop or outer loop (to support pragma omp declare).Do loop versioning
>>>>>>>>>>>>>> for innermost loop marked with pragma omp simd.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> 2014-08-01 13:40 GMT+04:00 Richard Biener <richard.guenther@gmail.com>:
>>>>>>>>>>>>>>> On Wed, Jun 25, 2014 at 4:06 PM, Yuri Rumyantsev <ysrumyan@gmail.com> wrote:
>>>>>>>>>>>>>>>> Hi All,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> We implemented additional support for pragma omp simd in part of
>>>>>>>>>>>>>>>> extended if-conversion loops with such pragma. These extensions
>>>>>>>>>>>>>>>> include:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 1. All extensions are performed only if considered loop or its outer
>>>>>>>>>>>>>>>> loop was marked with pragma omp simd (force_vectorize); For ordinary
>>>>>>>>>>>>>>>> loops behavior was not changed.
>>>>>>>>>>>>>>>> 2. Took off cfg restriction on basic block which can have more than 2
>>>>>>>>>>>>>>>> predecessors.
>>>>>>>>>>>>>>>> 3. Put additional restriction on phi nodes which was missed in current design:
>>>>>>>>>>>>>>>> all phi nodes must be in non-predicated basic block to conform
>>>>>>>>>>>>>>>> semantic of COND_EXPR which is used for transformation.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> How is that so? If the PHI is predicated then its result will be used
>>>>>>>>>>>>>>> in a PHI node again and thus we'd create a sequence of COND_EXPRs.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> No?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 4. Extend predication of phi nodes: phi may have more than 2 arguments
>>>>>>>>>>>>>>>> with some limitations:
>>>>>>>>>>>>>>>> - for phi nodes which have more than 2 arguments, but only two
>>>>>>>>>>>>>>>> arguments are different and one of them has the only occurence,
>>>>>>>>>>>>>>>> transformation to single COND_EXPR can be done.
>>>>>>>>>>>>>>>> - if phi node has more different arguments and all edge predicates
>>>>>>>>>>>>>>>> correspondent to phi-arguments are disjoint, a chain of COND_EXPR
>>>>>>>>>>>>>>>> will be generated for it. In current design very simple check is used:
>>>>>>>>>>>>>>>> check starting from end that two edges correspondent to neighbor
>>>>>>>>>>>>>>>> arguments have common predecessor which is used for further check
>>>>>>>>>>>>>>>> with next edge.
>>>>>>>>>>>>>>>> These guarantee that phi predication will produce the correct result.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Btw, you can think of these extensions as unfactoring a PHI node by
>>>>>>>>>>>>>>> inserting forwarder blocks. Thus
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> x = PHI <1(2), 1(3), 2(4)>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> becomes
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> bb 5: <forwarder-from(2)-and(3)>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> x = PHI <1(5), 2(4)>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> and
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> x = PHI <1(2), 2(3), 3(4)>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> becomes
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> bb 5:
>>>>>>>>>>>>>>> x' = PHI <1(2), 2(3)>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> b = PHI<x'(5), 3(4)>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> which means that 3) has to work. Note that we want this kind of
>>>>>>>>>>>>>>> PHI transforms for out-of-SSA as well to reduce the number of
>>>>>>>>>>>>>>> copies we need to insert on edges.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thus it would be nice if you implemented 4) in terms of a pre-pass
>>>>>>>>>>>>>>> over the force_vect loops PHI nodes, applying that CFG transform.
>>>>>>>>>>>>>>> And make 3) work properly if it doesn't already.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> It looks like you introduce a "negate predicate" to work around the
>>>>>>>>>>>>>>> critical edge limitation? Please instead change if-conversion to
>>>>>>>>>>>>>>> work with edge predicates (as opposed to BB predicates).
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>> Richard.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Here is example of such extended predication (compile with -march=core-avx2):
>>>>>>>>>>>>>>>> #pragma omp simd safelen(8)
>>>>>>>>>>>>>>>> for (i=0; i<512; i++)
>>>>>>>>>>>>>>>> {
>>>>>>>>>>>>>>>> float t = a[i];
>>>>>>>>>>>>>>>> if (t > 0 & t < 1.0e+17f)
>>>>>>>>>>>>>>>> if (c[i] != 0)
>>>>>>>>>>>>>>>> res += 1;
>>>>>>>>>>>>>>>> }
>>>>>>>>>>>>>>>> <bb 4>:
>>>>>>>>>>>>>>>> # res_15 = PHI <res_1(5), 0(3)>
>>>>>>>>>>>>>>>> # i_16 = PHI <i_11(5), 0(3)>
>>>>>>>>>>>>>>>> # ivtmp_17 = PHI <ivtmp_14(5), 512(3)>
>>>>>>>>>>>>>>>> t_5 = a[i_16];
>>>>>>>>>>>>>>>> _6 = t_5 > 0.0;
>>>>>>>>>>>>>>>> _7 = t_5 < 9.9999998430674944e+16;
>>>>>>>>>>>>>>>> _8 = _7 & _6;
>>>>>>>>>>>>>>>> _ifc__28 = (unsigned int) _8;
>>>>>>>>>>>>>>>> _10 = &c[i_16];
>>>>>>>>>>>>>>>> _ifc__36 = _ifc__28 != 0 ? 4294967295 : 0;
>>>>>>>>>>>>>>>> _9 = MASK_LOAD (_10, 0B, _ifc__36);
>>>>>>>>>>>>>>>> _ifc__29 = _ifc__28 != 0 ? 1 : 0;
>>>>>>>>>>>>>>>> _ifc__30 = (int) _ifc__29;
>>>>>>>>>>>>>>>> _ifc__31 = _9 != 0 ? _ifc__30 : 0;
>>>>>>>>>>>>>>>> _ifc__32 = _ifc__28 != 0 ? 1 : 0;
>>>>>>>>>>>>>>>> _ifc__33 = (int) _ifc__32;
>>>>>>>>>>>>>>>> _ifc__34 = _9 == 0 ? _ifc__33 : 0;
>>>>>>>>>>>>>>>> _ifc__35 = _ifc__31 != 0 ? 1 : 0;
>>>>>>>>>>>>>>>> res_1 = res_15 + _ifc__35;
>>>>>>>>>>>>>>>> i_11 = i_16 + 1;
>>>>>>>>>>>>>>>> ivtmp_14 = ivtmp_17 - 1;
>>>>>>>>>>>>>>>> if (ivtmp_14 != 0)
>>>>>>>>>>>>>>>> goto <bb 4>;
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Bootstrap and regression testing did not show any new failures.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> gcc/ChageLog
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 2014-06-25 Yuri Rumyantsev <ysrumyan@gmail.com>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> * tree-if-conv.c (flag_force_vectorize): New variable.
>>>>>>>>>>>>>>>> (struct bb_predicate_s): Add negate_predicate field.
>>>>>>>>>>>>>>>> (bb_negate_predicate): New function.
>>>>>>>>>>>>>>>> (set_bb_negate_predicate): New function.
>>>>>>>>>>>>>>>> (bb_copy_predicate): New function.
>>>>>>>>>>>>>>>> (add_stmt_to_bb_predicate_gimplified_stmts): New function.
>>>>>>>>>>>>>>>> (init_bb_predicate): Add initialization of negate_predicate field.
>>>>>>>>>>>>>>>> (reset_bb_predicate): Reset negate_predicate to NULL_TREE.
>>>>>>>>>>>>>>>> (convert_name_to_cmp): New function.
>>>>>>>>>>>>>>>> (get_type_for_cond): New function.
>>>>>>>>>>>>>>>> (convert_bool_predicate): New function.
>>>>>>>>>>>>>>>> (predicate_disjunction): New function.
>>>>>>>>>>>>>>>> (predicate_conjunction): New function.
>>>>>>>>>>>>>>>> (add_to_predicate_list): Add convert_bool argument.
>>>>>>>>>>>>>>>> Add call of predicate_disjunction if convert_bool argument is true.
>>>>>>>>>>>>>>>> (add_to_dst_predicate_list): Add convert_bool argument.
>>>>>>>>>>>>>>>> Add early function exit if edge target block is always executed.
>>>>>>>>>>>>>>>> Add call of predicate_conjunction if convert_bool argument is true.
>>>>>>>>>>>>>>>> Pass convert_bool argument for add_to_predicate_list.
>>>>>>>>>>>>>>>> (equal_phi_args): New function.
>>>>>>>>>>>>>>>> (phi_has_two_different_args): New function.
>>>>>>>>>>>>>>>> (phi_args_disjoint): New function.
>>>>>>>>>>>>>>>> (if_convertible_phi_p): Accept phi nodes with more than two args
>>>>>>>>>>>>>>>> for loops marked with pragma omp simd. Add check that phi nodes are
>>>>>>>>>>>>>>>> in non-predicated basic blocks.
>>>>>>>>>>>>>>>> (ifcvt_can_use_mask_load_store): Use flag_force_vectorize.
>>>>>>>>>>>>>>>> (all_edges_are_critical): New function.
>>>>>>>>>>>>>>>> (if_convertible_bb_p): Allow bb has more than two predecessors if
>>>>>>>>>>>>>>>> flag_force_vectorize was setup. Use call of all_edges_are_critical
>>>>>>>>>>>>>>>> to reject block if-conversion with imcoming critical edges only if
>>>>>>>>>>>>>>>> flag_force_vectorize was not setup.
>>>>>>>>>>>>>>>> (walk_cond_tree): New function.
>>>>>>>>>>>>>>>> (vect_bool_pattern_is_applicable): New function.
>>>>>>>>>>>>>>>> (predicate_bbs): Add convert_bool argument that is used to transform
>>>>>>>>>>>>>>>> comparison expressions of boolean type into conditional expressions
>>>>>>>>>>>>>>>> with integral operands. If bool_conv argument is false or both
>>>>>>>>>>>>>>>> outgoing edges are not critical old algorithm of predicate assignments
>>>>>>>>>>>>>>>> is used, otherwise the following code was added: check on applicable
>>>>>>>>>>>>>>>> of vect-bool-pattern recognition and trnasformation of
>>>>>>>>>>>>>>>> (bool) x != 0 --> y = (int) x; x != 0;
>>>>>>>>>>>>>>>> compute predicates for both outgoing edges one of which is critical
>>>>>>>>>>>>>>>> one using 'normal' edge, i.e. compute true and false predicates using
>>>>>>>>>>>>>>>> normal outgoing edge only; evaluated predicates are stored in
>>>>>>>>>>>>>>>> predicate and negate_predicate fields of struct bb_predicate_s and
>>>>>>>>>>>>>>>> negate_predicate of normal edge conatins predicate of critical edge,
>>>>>>>>>>>>>>>> but generated gimplified statements are stored in their destination
>>>>>>>>>>>>>>>> block fields. Additional argument 'convert_bool" is passed to
>>>>>>>>>>>>>>>> add_to_dst_predicate_list and add_to_predicate_list.
>>>>>>>>>>>>>>>> (if_convertible_loop_p_1): Call predicate_bbs with additional argument
>>>>>>>>>>>>>>>> equal to false.
>>>>>>>>>>>>>>>> (find_phi_replacement_condition): Extend function interface:
>>>>>>>>>>>>>>>> it returns NULL if given phi node must be handled by means of
>>>>>>>>>>>>>>>> extended phi node predication. If number of predecessors of phi-block
>>>>>>>>>>>>>>>> is equal 2 and atleast one incoming edge is not critical original
>>>>>>>>>>>>>>>> algorithm is used.
>>>>>>>>>>>>>>>> (is_cond_scalar_reduction): Add 'extended' argument which signals that
>>>>>>>>>>>>>>>> both phi arguments must be evaluated through phi_has_two_different_args.
>>>>>>>>>>>>>>>> (predicate_scalar_phi): Add invoсation of convert_name_to_cmp if cond
>>>>>>>>>>>>>>>> is SSA_NAME. Add 'false' argument to call of is_cond_scalar_reduction.
>>>>>>>>>>>>>>>> (get_predicate_for_edge): New function.
>>>>>>>>>>>>>>>> (find_insertion_point): New function.
>>>>>>>>>>>>>>>> (predicate_phi_disjoint_args): New function.
>>>>>>>>>>>>>>>> (predicate_extended_scalar_phi): New function.
>>>>>>>>>>>>>>>> (predicate_all_scalar_phis): Add code to set-up gimple statement
>>>>>>>>>>>>>>>> iterator for predication of extended scalar phi's for insertion.
>>>>>>>>>>>>>>>> (insert_gimplified_predicates): Add test for non-predicated basic
>>>>>>>>>>>>>>>> blocks that there are no gimplified statements to insert. Insert
>>>>>>>>>>>>>>>> predicates at the block begining for extended if-conversion.
>>>>>>>>>>>>>>>> (predicate_mem_writes): Invoke convert_name_to_cmp for extended
>>>>>>>>>>>>>>>> predication to build mask.
>>>>>>>>>>>>>>>> (combine_blocks): Pass flag_force_vectorize to predicate_bbs.
>>>>>>>>>>>>>>>> (split_crit_edge): New function.
>>>>>>>>>>>>>>>> (tree_if_conversion): Initialize flag_force_vectorize from current
>>>>>>>>>>>>>>>> loop or outer loop (to support pragma omp declare). Invoke
>>>>>>>>>>>>>>>> split_crit_edge for extended predication. Do loop versioning for
>>>>>>>>>>>>>>>> innermost loop marked with pragma omp simd.
More information about the Gcc-patches
mailing list