The two users of tree-data-ref's runtime alias checks both canonicalise
the order of the dr_with_seg_lens in a pair before passing them to
prune_runtime_alias_test_list. It's more convenient for later patches
if prune_runtime_alias_test_list does that itself.
2019-11-11 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* tree-data-ref.c (prune_runtime_alias_test_list): Sort the
two accesses in each dr_with_seg_len_pair_t before trying to
combine separate dr_with_seg_len_pair_ts.
* tree-loop-distribution.c (compute_alias_check_pairs): Don't do
that here.
* tree-vect-data-refs.c (vect_prune_runtime_alias_test_list): Likewise.
Index: gcc/tree-data-ref.c
===================================================================
--- gcc/tree-data-ref.c 2019-07-18 09:22:13.893767915 +0100
+++ gcc/tree-data-ref.c 2019-11-11 18:30:43.203244558 +0000
@@ -1487,13 +1487,32 @@ comp_dr_with_seg_len_pair (const void *p
prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *alias_pairs,
poly_uint64)
{
+ /* Canonicalize each pair so that the base components are ordered wrt
+ data_ref_compare_tree. This allows the loop below to merge more
+ cases. */
+ unsigned int i;
+ dr_with_seg_len_pair_t *alias_pair;
+ FOR_EACH_VEC_ELT (*alias_pairs, i, alias_pair)
+ {
+ data_reference_p dr_a = alias_pair->first.dr;
+ data_reference_p dr_b = alias_pair->second.dr;
+ int comp_res = data_ref_compare_tree (DR_BASE_ADDRESS (dr_a),
+ DR_BASE_ADDRESS (dr_b));
+ if (comp_res == 0)
+ comp_res = data_ref_compare_tree (DR_OFFSET (dr_a), DR_OFFSET (dr_b));
+ if (comp_res == 0)
+ comp_res = data_ref_compare_tree (DR_INIT (dr_a), DR_INIT (dr_b));
+ if (comp_res > 0)
+ std::swap (alias_pair->first, alias_pair->second);
+ }
+
/* Sort the collected data ref pairs so that we can scan them once to
combine all possible aliasing checks. */
alias_pairs->qsort (comp_dr_with_seg_len_pair);
/* Scan the sorted dr pairs and check if we can combine alias checks
of two neighboring dr pairs. */
- for (size_t i = 1; i < alias_pairs->length (); ++i)
+ for (i = 1; i < alias_pairs->length (); ++i)
{
/* Deal with two ddrs (dr_a1, dr_b1) and (dr_a2, dr_b2). */
dr_with_seg_len *dr_a1 = &(*alias_pairs)[i-1].first,
Index: gcc/tree-loop-distribution.c
===================================================================
--- gcc/tree-loop-distribution.c 2019-07-10 19:41:20.539944929 +0100
+++ gcc/tree-loop-distribution.c 2019-11-11 18:30:43.207244530 +0000
@@ -2457,12 +2457,6 @@ compute_alias_check_pairs (class loop *l
struct data_reference *dr_a = DDR_A (ddr);
struct data_reference *dr_b = DDR_B (ddr);
tree seg_length_a, seg_length_b;
- int comp_res = data_ref_compare_tree (DR_BASE_ADDRESS (dr_a),
- DR_BASE_ADDRESS (dr_b));
-
- if (comp_res == 0)
- comp_res = data_ref_compare_tree (DR_OFFSET (dr_a), DR_OFFSET (dr_b));
- gcc_assert (comp_res != 0);
if (latch_dominated_by_data_ref (loop, dr_a))
seg_length_a = data_ref_segment_size (dr_a, niters_plus_one);
@@ -2485,10 +2479,6 @@ compute_alias_check_pairs (class loop *l
(dr_with_seg_len (dr_a, seg_length_a, access_size_a, align_a),
dr_with_seg_len (dr_b, seg_length_b, access_size_b, align_b));
- /* Canonicalize pairs by sorting the two DR members. */
- if (comp_res > 0)
- std::swap (dr_with_seg_len_pair.first, dr_with_seg_len_pair.second);
-
comp_alias_pairs->safe_push (dr_with_seg_len_pair);
}
Index: gcc/tree-vect-data-refs.c
===================================================================
--- gcc/tree-vect-data-refs.c 2019-11-08 16:06:18.948980179 +0000
+++ gcc/tree-vect-data-refs.c 2019-11-11 18:30:43.207244530 +0000
@@ -3478,7 +3478,6 @@ vect_prune_runtime_alias_test_list (loop
/* First, we collect all data ref pairs for aliasing checks. */
FOR_EACH_VEC_ELT (may_alias_ddrs, i, ddr)
{
- int comp_res;
poly_uint64 lower_bound;
tree segment_length_a, segment_length_b;
unsigned HOST_WIDE_INT access_size_a, access_size_b;
@@ -3594,14 +3593,11 @@ vect_prune_runtime_alias_test_list (loop
align_a = vect_vfa_align (dr_info_a);
align_b = vect_vfa_align (dr_info_b);
- comp_res = data_ref_compare_tree (DR_BASE_ADDRESS (dr_info_a->dr),
- DR_BASE_ADDRESS (dr_info_b->dr));
- if (comp_res == 0)
- comp_res = data_ref_compare_tree (DR_OFFSET (dr_info_a->dr),
- DR_OFFSET (dr_info_b->dr));
-
/* See whether the alias is known at compilation time. */
- if (comp_res == 0
+ if (operand_equal_p (DR_BASE_ADDRESS (dr_info_a->dr),
+ DR_BASE_ADDRESS (dr_info_b->dr), 0)
+ && operand_equal_p (DR_OFFSET (dr_info_a->dr),
+ DR_OFFSET (dr_info_b->dr), 0)
&& TREE_CODE (DR_STEP (dr_info_a->dr)) == INTEGER_CST
&& TREE_CODE (DR_STEP (dr_info_b->dr)) == INTEGER_CST
&& poly_int_tree_p (segment_length_a)
@@ -3640,10 +3636,6 @@ vect_prune_runtime_alias_test_list (loop
dr_with_seg_len (dr_info_b->dr, segment_length_b,
access_size_b, align_b));
- /* Canonicalize pairs by sorting the two DR members. */
- if (comp_res > 0)
- std::swap (dr_with_seg_len_pair.first, dr_with_seg_len_pair.second);
-
comp_alias_ddrs.safe_push (dr_with_seg_len_pair);
}
