This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[RFC] [autovect patch] Implement vectorization hints

This patch implements two #pragmas that developers can use to give hints to auto vectorization pass. These pragmas are inserted in the source file before the loop. They are effective only on the very next loop in the source file.

"#pragma novector" instructs compiler to not vectorize the loop. Programmer may decide to do so for various reasons.

"#pragma ivdep" instructs compiler to ignore possible data dependence when data dependence analyzer is not able determine it. This is useful in a situation where compiler does not have enough information to prove data independence, but developer knows about it.

2005-02-24 Devang Patel <>

* (c-common.c): Depend on tree-flow.h, tree-data-ref.h
and tree-vectorizer.h.
* c-common.c (tree-flow.h, tree-data-ref.h, tree-vectorizer.h): Include.
(c_common_ivdep_pragma): New.
(c_common_novector_pragma): New.
* c-common.h (c_common_ivdep_pragma, c_common_novector_pragma): New.
* c-pragma.c (init_pragma): Register ivdeps and novector pragma handlers.
(struct location_range): New.
* tree-vectorizer.h (new_ivdep_pragma, new_novector_pragma): New.
(vect_pattern_recog_func): Moved to..
* tree-vectorizer.c (vect_pattern_recog_func): ... here.
(pragma_ivdep_on, pragma_novector_on): New.
(pragma_ivdep_active_p, pragma_novector_active_p, vect_pragma_lookup,
new_ivdep_pragma, new_novector_pragma):
New functions.
(vect_analyze_data_ref_dependence): Use pragma ivdep settings.
(vectorize_loops): Use pragma novector settings.
* tree.c (compare_location, new_location_range, location_inside_range_p):
New functions.
* tree.c (compare_location, new_location_range, location_inside_range_p):
* doc/exten.texi: Document #pragma ivdep and #pragma novector.

        * gcc.dg/vect/vect-pragma-1.c: New test.
        * gcc.dg/vect/vect-pragma-2.c: New test.


Attachment: av_pragma.diff
Description: Binary data

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]