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| author | Richard Biener <rguenther@suse.de> | 2014-02-21 13:18:54 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2014-02-21 13:18:54 +0000 |
| commit | f2556b68cad88433577a0baab1b76bef59f49d78 (patch) | |
| tree | 1e75ea5d008d884d77d7e4d771c8dff421db6753 /gcc/tree-vect-stmts.c | |
| parent | 32417082bf9a8f2633e7960f2e45979ebab43e51 (diff) | |
| download | gcc-f2556b68cad88433577a0baab1b76bef59f49d78.zip gcc-f2556b68cad88433577a0baab1b76bef59f49d78.tar.gz gcc-f2556b68cad88433577a0baab1b76bef59f49d78.tar.bz2 | |
re PR tree-optimization/60276 (-O3 autovectorizer breaks on a particular loop)
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.
From-SVN: r207992
Diffstat (limited to 'gcc/tree-vect-stmts.c')
| -rw-r--r-- | gcc/tree-vect-stmts.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c index 7e47feb..70fb411 100644 --- a/gcc/tree-vect-stmts.c +++ b/gcc/tree-vect-stmts.c @@ -5629,6 +5629,20 @@ vectorizable_load (gimple stmt, gimple_stmt_iterator *gsi, gimple *vec_stmt, return false; } + /* Invalidate assumptions made by dependence analysis when vectorization + on the unrolled body effectively re-orders stmts. */ + if (ncopies > 1 + && STMT_VINFO_MIN_NEG_DIST (stmt_info) != 0 + && ((unsigned)LOOP_VINFO_VECT_FACTOR (loop_vinfo) + > STMT_VINFO_MIN_NEG_DIST (stmt_info))) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "cannot perform implicit CSE when unrolling " + "with negative dependence distance\n"); + return false; + } + if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo) return false; @@ -5686,6 +5700,20 @@ vectorizable_load (gimple stmt, gimple_stmt_iterator *gsi, gimple *vec_stmt, else if (!vect_grouped_load_supported (vectype, group_size)) return false; } + + /* Invalidate assumptions made by dependence analysis when vectorization + on the unrolled body effectively re-orders stmts. */ + if (!PURE_SLP_STMT (stmt_info) + && STMT_VINFO_MIN_NEG_DIST (stmt_info) != 0 + && ((unsigned)LOOP_VINFO_VECT_FACTOR (loop_vinfo) + > STMT_VINFO_MIN_NEG_DIST (stmt_info))) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "cannot perform implicit CSE when performing " + "group loads with negative dependence distance\n"); + return false; + } } |