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| author | Richard Biener <rguenther@suse.de> | 2013-04-11 11:21:18 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2013-04-11 11:21:18 +0000 |
| commit | 4ba5ea117ac17ad00bb26b2cb64588ae345a6491 (patch) | |
| tree | 7131ce4ad93149ef59b657a80ec5ada7b65d7fb4 /gcc/tree-vect-data-refs.c | |
| parent | 983a3d80db525e9d7fbba6f222d3030bfc0a68ac (diff) | |
| download | gcc-4ba5ea117ac17ad00bb26b2cb64588ae345a6491.zip gcc-4ba5ea117ac17ad00bb26b2cb64588ae345a6491.tar.gz gcc-4ba5ea117ac17ad00bb26b2cb64588ae345a6491.tar.bz2 | |
re PR tree-optimization/56878 (Issue with candidate choice in vect_gen_niters_for_prolog_loop.)
2013-04-11 Richard Biener <rguenther@suse.de>
PR tree-optimization/56878
* tree-flow.h (outermost_invariant_loop_for_expr): Declare.
* tree-ssa-loop-ivopts.c (outermost_invariant_loop_for_expr):
New function.
* tree-vect-data-refs.c (vect_enhance_data_refs_alignment):
Prefer to align the DR with the most invariant base address.
From-SVN: r197769
Diffstat (limited to 'gcc/tree-vect-data-refs.c')
| -rw-r--r-- | gcc/tree-vect-data-refs.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index e20ab1f..64f2a8b 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -1456,20 +1456,35 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo) } else { - /* If we don't know all the misalignment values, we prefer - peeling for data-ref that has maximum number of data-refs + /* If we don't know any misalignment values, we prefer + peeling for data-ref that has the maximum number of data-refs with the same alignment, unless the target prefers to align stores over load. */ if (all_misalignments_unknown) { - if (same_align_drs_max - < STMT_VINFO_SAME_ALIGN_REFS (stmt_info).length () - || !dr0) + unsigned same_align_drs + = STMT_VINFO_SAME_ALIGN_REFS (stmt_info).length (); + if (!dr0 + || same_align_drs_max < same_align_drs) { - same_align_drs_max - = STMT_VINFO_SAME_ALIGN_REFS (stmt_info).length (); + same_align_drs_max = same_align_drs; dr0 = dr; } + /* For data-refs with the same number of related + accesses prefer the one where the misalign + computation will be invariant in the outermost loop. */ + else if (same_align_drs_max == same_align_drs) + { + struct loop *ivloop0, *ivloop; + ivloop0 = outermost_invariant_loop_for_expr + (loop, DR_BASE_ADDRESS (dr0)); + ivloop = outermost_invariant_loop_for_expr + (loop, DR_BASE_ADDRESS (dr)); + if ((ivloop && !ivloop0) + || (ivloop && ivloop0 + && flow_loop_nested_p (ivloop, ivloop0))) + dr0 = dr; + } if (!first_store && DR_IS_WRITE (dr)) first_store = dr; @@ -1478,8 +1493,6 @@ vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo) /* If there are both known and unknown misaligned accesses in the loop, we choose peeling amount according to the known accesses. */ - - if (!supportable_dr_alignment) { dr0 = dr; |