[Bug tree-optimization/60276] [4.7/4.8/4.9 Regression] -O3 autovectorizer breaks on a particular loop

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60276

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Feb 21 13:18:54 2014
New Revision: 207992

URL: http://gcc.gnu.org/viewcvs?rev=207992&root=gcc&view=rev
Log:
2014-02-21  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/60276
    * tree-vectorizer.h (struct _stmt_vec_info): Add min_neg_dist field.
    (STMT_VINFO_MIN_NEG_DIST): New macro.
    * tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Record
    STMT_VINFO_MIN_NEG_DIST.
    * tree-vect-stmts.c (vectorizable_load): Verify if assumptions
    made for negative dependence distances still hold.

    * gcc.dg/vect/pr60276.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr60276.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-data-refs.c
    trunk/gcc/tree-vect-stmts.c
    trunk/gcc/tree-vectorizer.h