diff options
Diffstat (limited to 'gcc/tree-data-ref.c')
| -rw-r--r-- | gcc/tree-data-ref.c | 57 |
1 files changed, 35 insertions, 22 deletions
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index 21cd2ad..bc5d213 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -1617,6 +1617,11 @@ prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *alias_pairs, std::swap (init_a1, init_a2); } + /* The DR_Bs are equal, so only the DR_As can introduce + mixed steps. */ + if (!operand_equal_p (DR_STEP (dr_a1->dr), DR_STEP (dr_a2->dr), 0)) + alias_pair1->flags |= DR_ALIAS_MIXED_STEPS; + if (new_seg_len_p) { dr_a1->seg_len = build_int_cst (TREE_TYPE (dr_a1->seg_len), @@ -1662,11 +1667,14 @@ prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *alias_pairs, } } -/* Given LOOP's two data references and segment lengths described by DR_A - and DR_B, create expression checking if the two addresses ranges intersect - with each other based on index of the two addresses. This can only be - done if DR_A and DR_B referring to the same (array) object and the index - is the only difference. For example: +/* Try to generate a runtime condition that is true if ALIAS_PAIR is + free of aliases, using a condition based on index values instead + of a condition based on addresses. Return true on success, + storing the condition in *COND_EXPR. + + This can only be done if the two data references in ALIAS_PAIR access + the same array object and the index is the only difference. For example, + if the two data references are DR_A and DR_B: DR_A DR_B data-ref arr[i] arr[j] @@ -1689,10 +1697,12 @@ prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *alias_pairs, static bool create_intersect_range_checks_index (class loop *loop, tree *cond_expr, - const dr_with_seg_len& dr_a, - const dr_with_seg_len& dr_b) + const dr_with_seg_len_pair_t &alias_pair) { - if (integer_zerop (DR_STEP (dr_a.dr)) + const dr_with_seg_len &dr_a = alias_pair.first; + const dr_with_seg_len &dr_b = alias_pair.second; + if ((alias_pair.flags & DR_ALIAS_MIXED_STEPS) + || integer_zerop (DR_STEP (dr_a.dr)) || integer_zerop (DR_STEP (dr_b.dr)) || DR_NUM_DIMENSIONS (dr_a.dr) != DR_NUM_DIMENSIONS (dr_b.dr)) return false; @@ -1914,24 +1924,26 @@ get_segment_min_max (const dr_with_seg_len &d, tree *seg_min_out, *seg_max_out = fold_build_pointer_plus (addr_base, max_reach); } -/* Given two data references and segment lengths described by DR_A and DR_B, - create expression checking if the two addresses ranges intersect with - each other: +/* Generate a runtime condition that is true if ALIAS_PAIR is free of aliases, + storing the condition in *COND_EXPR. The fallback is to generate a + a test that the two accesses do not overlap: - ((DR_A_addr_0 + DR_A_segment_length_0) <= DR_B_addr_0) - || (DR_B_addr_0 + DER_B_segment_length_0) <= DR_A_addr_0)) */ + end_a <= start_b || end_b <= start_a. */ static void create_intersect_range_checks (class loop *loop, tree *cond_expr, - const dr_with_seg_len& dr_a, - const dr_with_seg_len& dr_b) + const dr_with_seg_len_pair_t &alias_pair) { + const dr_with_seg_len& dr_a = alias_pair.first; + const dr_with_seg_len& dr_b = alias_pair.second; *cond_expr = NULL_TREE; - if (create_intersect_range_checks_index (loop, cond_expr, dr_a, dr_b)) + if (create_intersect_range_checks_index (loop, cond_expr, alias_pair)) return; unsigned HOST_WIDE_INT min_align; tree_code cmp_code; + /* We don't have to check DR_ALIAS_MIXED_STEPS here, since both versions + are equivalent. This is just an optimization heuristic. */ if (TREE_CODE (DR_STEP (dr_a.dr)) == INTEGER_CST && TREE_CODE (DR_STEP (dr_b.dr)) == INTEGER_CST) { @@ -1988,18 +2000,19 @@ create_runtime_alias_checks (class loop *loop, tree part_cond_expr; fold_defer_overflow_warnings (); - for (size_t i = 0, s = alias_pairs->length (); i < s; ++i) + dr_with_seg_len_pair_t *alias_pair; + unsigned int i; + FOR_EACH_VEC_ELT (*alias_pairs, i, alias_pair) { - const dr_with_seg_len& dr_a = (*alias_pairs)[i].first; - const dr_with_seg_len& dr_b = (*alias_pairs)[i].second; - + gcc_assert (alias_pair->flags); if (dump_enabled_p ()) dump_printf (MSG_NOTE, "create runtime check for data references %T and %T\n", - DR_REF (dr_a.dr), DR_REF (dr_b.dr)); + DR_REF (alias_pair->first.dr), + DR_REF (alias_pair->second.dr)); /* Create condition expression for each pair data references. */ - create_intersect_range_checks (loop, &part_cond_expr, dr_a, dr_b); + create_intersect_range_checks (loop, &part_cond_expr, *alias_pair); if (*cond_expr) *cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, *cond_expr, part_cond_expr); |