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Diffstat (limited to 'gcc/tree-vect-generic.c')
| -rw-r--r-- | gcc/tree-vect-generic.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/gcc/tree-vect-generic.c b/gcc/tree-vect-generic.c index a88b22f659..f33ff51fb1 100644 --- a/gcc/tree-vect-generic.c +++ b/gcc/tree-vect-generic.c @@ -1287,6 +1287,30 @@ lower_vec_perm (gimple_stmt_iterator *gsi) update_stmt (stmt); return; } + /* Also detect vec_shr pattern - VEC_PERM_EXPR with zero + vector as VEC1 and a right element shift MASK. */ + if (optab_handler (vec_shr_optab, TYPE_MODE (vect_type)) + != CODE_FOR_nothing + && TREE_CODE (vec1) == VECTOR_CST + && initializer_zerop (vec1) + && sel_int[0] + && sel_int[0] < elements) + { + for (i = 1; i < elements; ++i) + { + unsigned int expected = i + sel_int[0]; + /* Indices into the second vector are all equivalent. */ + if (MIN (elements, (unsigned) sel_int[i]) + != MIN (elements, expected)) + break; + } + if (i == elements) + { + gimple_assign_set_rhs3 (stmt, mask); + update_stmt (stmt); + return; + } + } } else if (can_vec_perm_p (TYPE_MODE (vect_type), true, NULL)) return; |