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| author | Richard Biener <rguenther@suse.de> | 2018-10-24 06:52:45 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2018-10-24 06:52:45 +0000 |
| commit | bf32992748c9849c38c089477d04b546e43ccdd1 (patch) | |
| tree | b6a79a842c11272da8db5e0f790b1cbb6bf0d410 /gcc/tree-vect-data-refs.c | |
| parent | 4b763deedb282b480fe4c2b3a8ad07192393f1b1 (diff) | |
| download | gcc-bf32992748c9849c38c089477d04b546e43ccdd1.zip gcc-bf32992748c9849c38c089477d04b546e43ccdd1.tar.gz gcc-bf32992748c9849c38c089477d04b546e43ccdd1.tar.bz2 | |
re PR tree-optimization/87665 (gcc HEAD (svn: 265340) breaks elements on resize)
2018-10-24 Richard Biener <rguenther@suse.de>
PR tree-optimization/87665
* tree-vect-data-refs.c (vect_preserves_scalar_order_p): Adjust
to reflect reality.
* gcc.dg/torture/pr87665.c: New testcase.
From-SVN: r265452
Diffstat (limited to 'gcc/tree-vect-data-refs.c')
| -rw-r--r-- | gcc/tree-vect-data-refs.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index 4b37114..a24e185 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -210,16 +210,26 @@ vect_preserves_scalar_order_p (dr_vec_info *dr_info_a, dr_vec_info *dr_info_b) return true; /* STMT_A and STMT_B belong to overlapping groups. All loads in a - group are emitted at the position of the first scalar load and all + group are emitted at the position of the last scalar load and all stores in a group are emitted at the position of the last scalar store. - Thus writes will happen no earlier than their current position - (but could happen later) while reads will happen no later than their - current position (but could happen earlier). Reordering is therefore - only possible if the first access is a write. */ - stmtinfo_a = vect_orig_stmt (stmtinfo_a); - stmtinfo_b = vect_orig_stmt (stmtinfo_b); - stmt_vec_info earlier_stmt_info = get_earlier_stmt (stmtinfo_a, stmtinfo_b); - return !DR_IS_WRITE (STMT_VINFO_DATA_REF (earlier_stmt_info)); + Compute that position and check whether the resulting order matches + the current one. */ + stmt_vec_info last_a = DR_GROUP_FIRST_ELEMENT (stmtinfo_a); + if (last_a) + for (stmt_vec_info s = DR_GROUP_NEXT_ELEMENT (last_a); s; + s = DR_GROUP_NEXT_ELEMENT (s)) + last_a = get_later_stmt (last_a, s); + else + last_a = stmtinfo_a; + stmt_vec_info last_b = DR_GROUP_FIRST_ELEMENT (stmtinfo_b); + if (last_b) + for (stmt_vec_info s = DR_GROUP_NEXT_ELEMENT (last_b); s; + s = DR_GROUP_NEXT_ELEMENT (s)) + last_b = get_later_stmt (last_b, s); + else + last_b = stmtinfo_b; + return ((get_later_stmt (last_a, last_b) == last_a) + == (get_later_stmt (stmtinfo_a, stmtinfo_b) == stmtinfo_a)); } /* A subroutine of vect_analyze_data_ref_dependence. Handle |