/* Data references and dependences detectors.
- Copyright (C) 2003-2019 Free Software Foundation, Inc.
+ Copyright (C) 2003-2020 Free Software Foundation, Inc.
Contributed by Sebastian Pop <pop@cri.ensmp.fr>
This file is part of GCC.
#include "builtins.h"
#include "tree-eh.h"
#include "ssa.h"
+#include "internal-fn.h"
static struct datadep_stats
{
prune_runtime_alias_test_list (vec<dr_with_seg_len_pair_t> *alias_pairs,
poly_uint64)
{
+ if (alias_pairs->is_empty ())
+ return;
+
/* Canonicalize each pair so that the base components are ordered wrt
data_ref_compare_tree. This allows the loop below to merge more
cases. */
/* Scan the sorted dr pairs and check if we can combine alias checks
of two neighboring dr pairs. */
+ unsigned int last = 0;
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_pair_t *alias_pair1 = &(*alias_pairs)[i - 1];
+ dr_with_seg_len_pair_t *alias_pair1 = &(*alias_pairs)[last];
dr_with_seg_len_pair_t *alias_pair2 = &(*alias_pairs)[i];
dr_with_seg_len *dr_a1 = &alias_pair1->first;
DR_REF (dr_a1->dr), DR_REF (dr_b1->dr),
DR_REF (dr_a2->dr), DR_REF (dr_b2->dr));
alias_pair1->flags |= alias_pair2->flags;
- alias_pairs->ordered_remove (i--);
continue;
}
+ /* Assume that we won't be able to merge the pairs, then correct
+ if we do. */
+ last += 1;
+ if (last != i)
+ (*alias_pairs)[last] = (*alias_pairs)[i];
+
if (*dr_a1 == *dr_a2 || *dr_b1 == *dr_b2)
{
/* We consider the case that DR_B1 and DR_B2 are same memrefs,
DR_REF (dr_a1->dr), DR_REF (dr_b1->dr),
DR_REF (dr_a2->dr), DR_REF (dr_b2->dr));
alias_pair1->flags |= alias_pair2->flags;
- alias_pairs->ordered_remove (i);
- i--;
+ last -= 1;
}
}
+ alias_pairs->truncate (last + 1);
/* Try to restore the original dr_with_seg_len order within each
dr_with_seg_len_pair_t. If we ended up combining swapped and
}
}
+/* A subroutine of create_intersect_range_checks, with a subset of the
+ same arguments. Try to use IFN_CHECK_RAW_PTRS and IFN_CHECK_WAR_PTRS
+ to optimize cases in which the references form a simple RAW, WAR or
+ WAR dependence. */
+
+static bool
+create_ifn_alias_checks (tree *cond_expr,
+ 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;
+
+ /* Check for cases in which:
+
+ (a) we have a known RAW, WAR or WAR dependence
+ (b) the accesses are well-ordered in both the original and new code
+ (see the comment above the DR_ALIAS_* flags for details); and
+ (c) the DR_STEPs describe all access pairs covered by ALIAS_PAIR. */
+ if (alias_pair.flags & ~(DR_ALIAS_RAW | DR_ALIAS_WAR | DR_ALIAS_WAW))
+ return false;
+
+ /* Make sure that both DRs access the same pattern of bytes,
+ with a constant length and and step. */
+ poly_uint64 seg_len;
+ if (!operand_equal_p (dr_a.seg_len, dr_b.seg_len, 0)
+ || !poly_int_tree_p (dr_a.seg_len, &seg_len)
+ || maybe_ne (dr_a.access_size, dr_b.access_size)
+ || !operand_equal_p (DR_STEP (dr_a.dr), DR_STEP (dr_b.dr), 0)
+ || !tree_fits_uhwi_p (DR_STEP (dr_a.dr)))
+ return false;
+
+ unsigned HOST_WIDE_INT bytes = tree_to_uhwi (DR_STEP (dr_a.dr));
+ tree addr_a = DR_BASE_ADDRESS (dr_a.dr);
+ tree addr_b = DR_BASE_ADDRESS (dr_b.dr);
+
+ /* See whether the target suports what we want to do. WAW checks are
+ equivalent to WAR checks here. */
+ internal_fn ifn = (alias_pair.flags & DR_ALIAS_RAW
+ ? IFN_CHECK_RAW_PTRS
+ : IFN_CHECK_WAR_PTRS);
+ unsigned int align = MIN (dr_a.align, dr_b.align);
+ poly_uint64 full_length = seg_len + bytes;
+ if (!internal_check_ptrs_fn_supported_p (ifn, TREE_TYPE (addr_a),
+ full_length, align))
+ {
+ full_length = seg_len + dr_a.access_size;
+ if (!internal_check_ptrs_fn_supported_p (ifn, TREE_TYPE (addr_a),
+ full_length, align))
+ return false;
+ }
+
+ /* Commit to using this form of test. */
+ addr_a = fold_build_pointer_plus (addr_a, DR_OFFSET (dr_a.dr));
+ addr_a = fold_build_pointer_plus (addr_a, DR_INIT (dr_a.dr));
+
+ addr_b = fold_build_pointer_plus (addr_b, DR_OFFSET (dr_b.dr));
+ addr_b = fold_build_pointer_plus (addr_b, DR_INIT (dr_b.dr));
+
+ *cond_expr = build_call_expr_internal_loc (UNKNOWN_LOCATION,
+ ifn, boolean_type_node,
+ 4, addr_a, addr_b,
+ size_int (full_length),
+ size_int (align));
+
+ if (dump_enabled_p ())
+ {
+ if (ifn == IFN_CHECK_RAW_PTRS)
+ dump_printf (MSG_NOTE, "using an IFN_CHECK_RAW_PTRS test\n");
+ else
+ dump_printf (MSG_NOTE, "using an IFN_CHECK_WAR_PTRS test\n");
+ }
+ return true;
+}
+
/* 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,
if (create_intersect_range_checks_index (loop, cond_expr, alias_pair))
return;
+ if (create_ifn_alias_checks (cond_expr, alias_pair))
+ return;
+
if (create_waw_or_war_checks (cond_expr, alias_pair))
return;
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