*cond_expr = part_cond_expr;
}
+/* 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 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:
+
+ DR_A DR_B
+ data-ref arr[i] arr[j]
+ base_object arr arr
+ index {i_0, +, 1}_loop {j_0, +, 1}_loop
+
+ The addresses and their index are like:
+
+ |<- ADDR_A ->| |<- ADDR_B ->|
+ ------------------------------------------------------->
+ | | | | | | | | | |
+ ------------------------------------------------------->
+ i_0 ... i_0+4 j_0 ... j_0+4
+
+ We can create expression based on index rather than address:
+
+ (i_0 + 4 < j_0 || j_0 + 4 < i_0)
+
+ Note evolution step of index needs to be considered in comparison. */
+
+static bool
+create_intersect_range_checks_index (loop_vec_info loop_vinfo, tree *cond_expr,
+ const dr_with_seg_len& dr_a,
+ const dr_with_seg_len& dr_b)
+{
+ if (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;
+
+ if (!tree_fits_uhwi_p (dr_a.seg_len) || !tree_fits_uhwi_p (dr_b.seg_len))
+ return false;
+
+ if (!operand_equal_p (DR_BASE_OBJECT (dr_a.dr), DR_BASE_OBJECT (dr_b.dr), 0))
+ return false;
+
+ if (!operand_equal_p (DR_STEP (dr_a.dr), DR_STEP (dr_b.dr), 0))
+ return false;
+
+ gcc_assert (TREE_CODE (DR_STEP (dr_a.dr)) == INTEGER_CST);
+
+ bool neg_step = tree_int_cst_compare (DR_STEP (dr_a.dr), size_zero_node) < 0;
+ unsigned HOST_WIDE_INT abs_step = tree_to_uhwi (DR_STEP (dr_a.dr));
+ if (neg_step)
+ abs_step = -abs_step;
+
+ unsigned HOST_WIDE_INT seg_len1 = tree_to_uhwi (dr_a.seg_len);
+ unsigned HOST_WIDE_INT seg_len2 = tree_to_uhwi (dr_b.seg_len);
+ /* Infer the number of iterations with which the memory segment is accessed
+ by DR. In other words, alias is checked if memory segment accessed by
+ DR_A in some iterations intersect with memory segment accessed by DR_B
+ in the same amount iterations.
+ Note segnment length is a linear function of number of iterations with
+ DR_STEP as the coefficient. */
+ unsigned HOST_WIDE_INT niter_len1 = (seg_len1 + abs_step - 1) / abs_step;
+ unsigned HOST_WIDE_INT niter_len2 = (seg_len2 + abs_step - 1) / abs_step;
+
+ unsigned int i;
+ struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
+ for (i = 0; i < DR_NUM_DIMENSIONS (dr_a.dr); i++)
+ {
+ tree access1 = DR_ACCESS_FN (dr_a.dr, i);
+ tree access2 = DR_ACCESS_FN (dr_b.dr, i);
+ /* Two index must be the same if they are not scev, or not scev wrto
+ current loop being vecorized. */
+ if (TREE_CODE (access1) != POLYNOMIAL_CHREC
+ || TREE_CODE (access2) != POLYNOMIAL_CHREC
+ || CHREC_VARIABLE (access1) != (unsigned)loop->num
+ || CHREC_VARIABLE (access2) != (unsigned)loop->num)
+ {
+ if (operand_equal_p (access1, access2, 0))
+ continue;
+
+ return false;
+ }
+ /* Two index must have the same step. */
+ if (!operand_equal_p (CHREC_RIGHT (access1), CHREC_RIGHT (access2), 0))
+ return false;
+
+ tree idx_step = CHREC_RIGHT (access1);
+ /* Index must have const step, otherwise DR_STEP won't be constant. */
+ gcc_assert (TREE_CODE (idx_step) == INTEGER_CST);
+ /* Index must evaluate in the same direction as DR. */
+ gcc_assert (!neg_step
+ || tree_int_cst_compare (idx_step, size_zero_node) < 0);
+
+ tree min1 = CHREC_LEFT (access1);
+ tree min2 = CHREC_LEFT (access2);
+ if (!types_compatible_p (TREE_TYPE (min1), TREE_TYPE (min2)))
+ return false;
+
+ /* Ideally, alias can be checked against loop's control IV, but we
+ need to prove linear mapping between control IV and reference
+ index. Although that should be true, we check against (array)
+ index of data reference. Like segment length, index length is
+ linear function of the number of iterations with index_step as
+ the coefficient, i.e, niter_len * idx_step. */
+ tree idx_len1 = fold_build2 (MULT_EXPR, TREE_TYPE (min1), idx_step,
+ build_int_cst (TREE_TYPE (min1),
+ niter_len1));
+ tree idx_len2 = fold_build2 (MULT_EXPR, TREE_TYPE (min2), idx_step,
+ build_int_cst (TREE_TYPE (min2),
+ niter_len2));
+ tree max1 = fold_build2 (PLUS_EXPR, TREE_TYPE (min1), min1, idx_len1);
+ tree max2 = fold_build2 (PLUS_EXPR, TREE_TYPE (min2), min2, idx_len2);
+ /* Adjust ranges for negative step. */
+ if (neg_step)
+ {
+ min1 = fold_build2 (MINUS_EXPR, TREE_TYPE (min1), max1, idx_step);
+ max1 = fold_build2 (MINUS_EXPR, TREE_TYPE (min1),
+ CHREC_LEFT (access1), idx_step);
+ min2 = fold_build2 (MINUS_EXPR, TREE_TYPE (min2), max2, idx_step);
+ max2 = fold_build2 (MINUS_EXPR, TREE_TYPE (min2),
+ CHREC_LEFT (access2), idx_step);
+ }
+ tree part_cond_expr
+ = fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
+ fold_build2 (LE_EXPR, boolean_type_node, max1, min2),
+ fold_build2 (LE_EXPR, boolean_type_node, max2, min1));
+ if (*cond_expr)
+ *cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+ *cond_expr, part_cond_expr);
+ else
+ *cond_expr = part_cond_expr;
+ }
+ return true;
+}
+
+/* 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:
+
+ ((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)) */
+
+static void
+create_intersect_range_checks (loop_vec_info loop_vinfo, tree *cond_expr,
+ const dr_with_seg_len& dr_a,
+ const dr_with_seg_len& dr_b)
+{
+ *cond_expr = NULL_TREE;
+ if (create_intersect_range_checks_index (loop_vinfo, cond_expr, dr_a, dr_b))
+ return;
+
+ tree segment_length_a = dr_a.seg_len;
+ tree segment_length_b = dr_b.seg_len;
+ tree addr_base_a = DR_BASE_ADDRESS (dr_a.dr);
+ tree addr_base_b = DR_BASE_ADDRESS (dr_b.dr);
+ tree offset_a = DR_OFFSET (dr_a.dr), offset_b = DR_OFFSET (dr_b.dr);
+
+ offset_a = fold_build2 (PLUS_EXPR, TREE_TYPE (offset_a),
+ offset_a, DR_INIT (dr_a.dr));
+ offset_b = fold_build2 (PLUS_EXPR, TREE_TYPE (offset_b),
+ offset_b, DR_INIT (dr_b.dr));
+ addr_base_a = fold_build_pointer_plus (addr_base_a, offset_a);
+ addr_base_b = fold_build_pointer_plus (addr_base_b, offset_b);
+
+ tree seg_a_min = addr_base_a;
+ tree seg_a_max = fold_build_pointer_plus (addr_base_a, segment_length_a);
+ /* For negative step, we need to adjust address range by TYPE_SIZE_UNIT
+ bytes, e.g., int a[3] -> a[1] range is [a+4, a+16) instead of
+ [a, a+12) */
+ if (tree_int_cst_compare (DR_STEP (dr_a.dr), size_zero_node) < 0)
+ {
+ tree unit_size = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr_a.dr)));
+ seg_a_min = fold_build_pointer_plus (seg_a_max, unit_size);
+ seg_a_max = fold_build_pointer_plus (addr_base_a, unit_size);
+ }
+
+ tree seg_b_min = addr_base_b;
+ tree seg_b_max = fold_build_pointer_plus (addr_base_b, segment_length_b);
+ if (tree_int_cst_compare (DR_STEP (dr_b.dr), size_zero_node) < 0)
+ {
+ tree unit_size = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr_b.dr)));
+ seg_b_min = fold_build_pointer_plus (seg_b_max, unit_size);
+ seg_b_max = fold_build_pointer_plus (addr_base_b, unit_size);
+ }
+ *cond_expr
+ = fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
+ fold_build2 (LE_EXPR, boolean_type_node, seg_a_max, seg_b_min),
+ fold_build2 (LE_EXPR, boolean_type_node, seg_b_max, seg_a_min));
+}
+
/* Function vect_create_cond_for_alias_checks.
Create a conditional expression that represents the run-time checks for
LOOP_VINFO_COMP_ALIAS_DDRS (loop_vinfo);
tree part_cond_expr;
- /* Create expression
- ((store_ptr_0 + store_segment_length_0) <= load_ptr_0)
- || (load_ptr_0 + load_segment_length_0) <= store_ptr_0))
- &&
- ...
- &&
- ((store_ptr_n + store_segment_length_n) <= load_ptr_n)
- || (load_ptr_n + load_segment_length_n) <= store_ptr_n)) */
-
if (comp_alias_ddrs.is_empty ())
return;
{
const dr_with_seg_len& dr_a = comp_alias_ddrs[i].first;
const dr_with_seg_len& dr_b = comp_alias_ddrs[i].second;
- tree segment_length_a = dr_a.seg_len;
- tree segment_length_b = dr_b.seg_len;
- tree addr_base_a = DR_BASE_ADDRESS (dr_a.dr);
- tree addr_base_b = DR_BASE_ADDRESS (dr_b.dr);
- tree offset_a = DR_OFFSET (dr_a.dr), offset_b = DR_OFFSET (dr_b.dr);
-
- offset_a = fold_build2 (PLUS_EXPR, TREE_TYPE (offset_a),
- offset_a, DR_INIT (dr_a.dr));
- offset_b = fold_build2 (PLUS_EXPR, TREE_TYPE (offset_b),
- offset_b, DR_INIT (dr_b.dr));
- addr_base_a = fold_build_pointer_plus (addr_base_a, offset_a);
- addr_base_b = fold_build_pointer_plus (addr_base_b, offset_b);
if (dump_enabled_p ())
{
dump_printf (MSG_NOTE, "\n");
}
- tree seg_a_min = addr_base_a;
- tree seg_a_max = fold_build_pointer_plus (addr_base_a, segment_length_a);
- /* For negative step, we need to adjust address range by TYPE_SIZE_UNIT
- bytes, e.g., int a[3] -> a[1] range is [a+4, a+16) instead of
- [a, a+12) */
- if (tree_int_cst_compare (DR_STEP (dr_a.dr), size_zero_node) < 0)
- {
- tree unit_size = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr_a.dr)));
- seg_a_min = fold_build_pointer_plus (seg_a_max, unit_size);
- seg_a_max = fold_build_pointer_plus (addr_base_a, unit_size);
- }
-
- tree seg_b_min = addr_base_b;
- tree seg_b_max = fold_build_pointer_plus (addr_base_b, segment_length_b);
- if (tree_int_cst_compare (DR_STEP (dr_b.dr), size_zero_node) < 0)
- {
- tree unit_size = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr_b.dr)));
- seg_b_min = fold_build_pointer_plus (seg_b_max, unit_size);
- seg_b_max = fold_build_pointer_plus (addr_base_b, unit_size);
- }
-
- part_cond_expr =
- fold_build2 (TRUTH_OR_EXPR, boolean_type_node,
- fold_build2 (LE_EXPR, boolean_type_node, seg_a_max, seg_b_min),
- fold_build2 (LE_EXPR, boolean_type_node, seg_b_max, seg_a_min));
-
+ /* Create condition expression for each pair data references. */
+ create_intersect_range_checks (loop_vinfo, &part_cond_expr, dr_a, dr_b);
if (*cond_expr)
*cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
*cond_expr, part_cond_expr);
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