[PATCH 3/3] extended if-conversion

[Yuri Rumyantsev <ysrumyan at gmail dot com>]

Hi All,

Here is the last part of patch which is related to vectorization
improvements, namely

1. New sub-phase is added which delete  dead predicate computations
(such code can prevent loop vectorization since dead computation are
not part of bool pattern tree). It is invoked only under
FLAG_FORCE_VECTORIZE.
2. New sub-phase is added to provide single uses in tree correspondent
to bool pattern (it takes place when the same predicate is used for
PHI-node predication and predicated memory access through 'mask'). To
do it some code replication is used. It is invoked only under
FLAG_FORCE_VECTORIZE.
3. I added simple optimization for predicate_mem_writes - do not
generate new mask if it has been produced for given size.
4. simple change was made in fold_build_cond_expr to simplify
predicate of kind r != 0 where r has boolean type to simply 'r' which
is accepted by bool pattern recognition.

ChangeLog:

2014-11-12  Yuri Rumyantsev  <ysrumyan@gmail.com>

* tree-if-conv.c (fold_build_cond_expr): Add conversion COND to
SSA_NAME if it is comparison r != 0 and r has boolean type.
(predicate_mem_writes): Introduce mask_vec to save mask correspondent
to given size. Do not generate new mask if it exists for given size.
(ifcvt_split_def_stmt): New function.
(ifcvt_walk_pattern_tree): New function.
(stmt_is_root_of_bool_pattern): New function.
(ifcvt_repair_bool_pattern): New function.
(ifcvt_local_dce): New function.
(tree_if_conversion): Add calls of ifcvt_local_dce and
ifcvt_repair_bool_pattern if FLAG_FORCE_VECTORIZE is true.

Attachment: if-conv.patch3
Description: Binary data