return 0;
}
-struct tree_opt_pass pass_referenced_vars =
+struct gimple_opt_pass pass_referenced_vars =
{
+ {
+ GIMPLE_PASS,
NULL, /* name */
NULL, /* gate */
find_referenced_vars, /* execute */
PROP_referenced_vars, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ 0 /* todo_flags_finish */
+ }
};
}
-/* Dump sub-variables for VAR to FILE. */
-
-void
-dump_subvars_for (FILE *file, tree var)
-{
- subvar_t sv = get_subvars_for_var (var);
- tree subvar;
- unsigned int i;
-
- if (!sv)
- return;
-
- fprintf (file, "{ ");
-
- for (i = 0; VEC_iterate (tree, sv, i, subvar); ++i)
- {
- print_generic_expr (file, subvar, dump_flags);
- fprintf (file, "@" HOST_WIDE_INT_PRINT_UNSIGNED, SFT_OFFSET (subvar));
- if (SFT_BASE_FOR_COMPONENTS_P (subvar))
- fprintf (file, "[B]");
- fprintf (file, " ");
- }
-
- fprintf (file, "}");
-}
-
-
-/* Dumb sub-variables for VAR to stderr. */
-
-void
-debug_subvars_for (tree var)
-{
- dump_subvars_for (stderr, var);
-}
-
-
/* Dump variable VAR and its may-aliases to FILE. */
void
dump_may_aliases_for (file, var);
}
- if (get_subvars_for_var (var))
- {
- fprintf (file, ", sub-vars: ");
- dump_subvars_for (file, var);
- }
-
if (!is_gimple_reg (var))
{
if (memory_partition (var))
fprintf (file, ", partition symbols: ");
dump_decl_set (file, MPT_SYMBOLS (var));
}
-
- if (TREE_CODE (var) == STRUCT_FIELD_TAG)
- {
- fprintf (file, ", offset: " HOST_WIDE_INT_PRINT_UNSIGNED,
- SFT_OFFSET (var));
- fprintf (file, ", base for components: %s",
- SFT_BASE_FOR_COMPONENTS_P (var) ? "NO" : "YES");
- fprintf (file, ", partitionable: %s",
- SFT_UNPARTITIONABLE_P (var) ? "NO" : "YES");
- }
}
fprintf (file, "\n");
tree
referenced_var_lookup (unsigned int uid)
{
- tree var;
-
- gcc_assert (bitmap_bit_p (gimple_referenced_vars (cfun), uid));
-
- /* For now also assert that the variable is really referenced.
- Otherwise callers need to deal with the result from this function
- being NULL. */
- var = lookup_decl_from_uid (uid);
- gcc_assert (var);
- return var;
+ tree h;
+ struct tree_decl_minimal in;
+ in.uid = uid;
+ h = (tree) htab_find_with_hash (gimple_referenced_vars (cfun), &in, uid);
+ gcc_assert (h || uid == 0);
+ return h;
}
/* Check if TO is in the referenced_vars hash table and insert it if not.
bool
referenced_var_check_and_insert (tree to)
{
+ tree h, *loc;
+ struct tree_decl_minimal in;
unsigned int uid = DECL_UID (to);
- if (bitmap_bit_p (gimple_referenced_vars (cfun), uid))
- return false;
-
- bitmap_set_bit (gimple_referenced_vars (cfun), uid);
+ in.uid = uid;
+ h = (tree) htab_find_with_hash (gimple_referenced_vars (cfun), &in, uid);
+ if (h)
+ {
+ /* DECL_UID has already been entered in the table. Verify that it is
+ the same entry as TO. See PR 27793. */
+ gcc_assert (h == to);
+ return false;
+ }
+ loc = (tree *) htab_find_slot_with_hash (gimple_referenced_vars (cfun),
+ &in, uid, INSERT);
+ *loc = to;
return true;
}
remove_referenced_var (tree var)
{
var_ann_t v_ann;
+ struct tree_decl_minimal in;
+ void **loc;
unsigned int uid = DECL_UID (var);
- subvar_t sv;
-
- /* If we remove a var, we should also remove its subvars, as we kill
- their parent var and its annotation. */
- if (var_can_have_subvars (var)
- && (sv = get_subvars_for_var (var)))
- {
- unsigned int i;
- tree subvar;
- for (i = 0; VEC_iterate (tree, sv, i, subvar); ++i)
- remove_referenced_var (subvar);
- }
clear_call_clobbered (var);
if ((v_ann = var_ann (var)))
ggc_free (v_ann);
var->base.ann = NULL;
gcc_assert (DECL_P (var));
- bitmap_clear_bit (gimple_referenced_vars (cfun), uid);
+ in.uid = uid;
+ loc = htab_find_slot_with_hash (gimple_referenced_vars (cfun), &in, uid,
+ NO_INSERT);
+ htab_clear_slot (gimple_referenced_vars (cfun), loc);
}
return false;
}
+/* Return true, if the two memory references REF1 and REF2 may alias. */
+
+bool
+refs_may_alias_p (tree ref1, tree ref2)
+{
+ tree base1, base2;
+ HOST_WIDE_INT offset1 = 0, offset2 = 0;
+ HOST_WIDE_INT size1 = -1, size2 = -1;
+ HOST_WIDE_INT max_size1 = -1, max_size2 = -1;
+
+ gcc_assert ((SSA_VAR_P (ref1)
+ || handled_component_p (ref1)
+ || TREE_CODE (ref1) == INDIRECT_REF)
+ && (SSA_VAR_P (ref2)
+ || handled_component_p (ref2)
+ || TREE_CODE (ref2) == INDIRECT_REF));
+
+ /* Defer to TBAA if possible. */
+ if (flag_strict_aliasing
+ && !alias_sets_conflict_p (get_alias_set (ref1), get_alias_set (ref2)))
+ return false;
+
+ /* Decompose the references into their base objects and the access. */
+ base1 = ref1;
+ if (handled_component_p (ref1))
+ base1 = get_ref_base_and_extent (ref1, &offset1, &size1, &max_size1);
+ base2 = ref2;
+ if (handled_component_p (ref2))
+ base2 = get_ref_base_and_extent (ref2, &offset2, &size2, &max_size2);
+
+ /* If both references are based on different variables, they cannot alias.
+ If both references are based on the same variable, they cannot alias if
+ if the accesses do not overlap. */
+ if (SSA_VAR_P (base1)
+ && SSA_VAR_P (base2)
+ && (!operand_equal_p (base1, base2, 0)
+ || !ranges_overlap_p (offset1, max_size1, offset2, max_size2)))
+ return false;
+
+ /* If both references are through pointers and both pointers are equal
+ then they do not alias if the accesses do not overlap. */
+ if (TREE_CODE (base1) == INDIRECT_REF
+ && TREE_CODE (base2) == INDIRECT_REF
+ && operand_equal_p (TREE_OPERAND (base1, 0),
+ TREE_OPERAND (base2, 0), 0)
+ && !ranges_overlap_p (offset1, max_size1, offset2, max_size2))
+ return false;
+
+ return true;
+}
+
+/* Given a stmt STMT that references memory, return the single stmt
+ that is reached by following the VUSE -> VDEF link. Returns
+ NULL_TREE, if there is no single stmt that defines all VUSEs of
+ STMT.
+ Note that for a stmt with a single virtual operand this may return
+ a PHI node as well. Note that if all VUSEs are default definitions
+ this function will return an empty statement. */
+
+tree
+get_single_def_stmt (tree stmt)
+{
+ tree def_stmt = NULL_TREE;
+ tree use;
+ ssa_op_iter iter;
+
+ FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_VIRTUAL_USES)
+ {
+ tree tmp = SSA_NAME_DEF_STMT (use);
+
+ /* ??? This is too simplistic for multiple virtual operands
+ reaching different PHI nodes of the same basic blocks or for
+ reaching all default definitions. */
+ if (def_stmt
+ && def_stmt != tmp
+ && !(IS_EMPTY_STMT (def_stmt)
+ && IS_EMPTY_STMT (tmp)))
+ return NULL_TREE;
+
+ def_stmt = tmp;
+ }
+
+ return def_stmt;
+}
+
+/* Given a PHI node of virtual operands, tries to eliminate cyclic
+ reached definitions if they do not alias REF and returns the
+ defining statement of the single virtual operand that flows in
+ from a non-backedge. Returns NULL_TREE if such statement within
+ the above conditions cannot be found. */
+
+tree
+get_single_def_stmt_from_phi (tree ref, tree phi)
+{
+ tree def_arg = NULL_TREE;
+ int i;
+
+ /* Find the single PHI argument that is not flowing in from a
+ back edge and verify that the loop-carried definitions do
+ not alias the reference we look for. */
+ for (i = 0; i < PHI_NUM_ARGS (phi); ++i)
+ {
+ tree arg = PHI_ARG_DEF (phi, i);
+ tree def_stmt;
+
+ if (!(PHI_ARG_EDGE (phi, i)->flags & EDGE_DFS_BACK))
+ {
+ /* Multiple non-back edges? Do not try to handle this. */
+ if (def_arg)
+ return NULL_TREE;
+ def_arg = arg;
+ continue;
+ }
+
+ /* Follow the definitions back to the original PHI node. Bail
+ out once a definition is found that may alias REF. */
+ def_stmt = SSA_NAME_DEF_STMT (arg);
+ do
+ {
+ if (TREE_CODE (def_stmt) != GIMPLE_MODIFY_STMT
+ || refs_may_alias_p (ref, GIMPLE_STMT_OPERAND (def_stmt, 0)))
+ return NULL_TREE;
+ /* ??? This will only work, reaching the PHI node again if
+ there is a single virtual operand on def_stmt. */
+ def_stmt = get_single_def_stmt (def_stmt);
+ if (!def_stmt)
+ return NULL_TREE;
+ }
+ while (def_stmt != phi);
+ }
+
+ return SSA_NAME_DEF_STMT (def_arg);
+}
+
+/* Return the single reference statement defining all virtual uses
+ on STMT or NULL_TREE, if there are multiple defining statements.
+ Take into account only definitions that alias REF if following
+ back-edges when looking through a loop PHI node. */
+
+tree
+get_single_def_stmt_with_phi (tree ref, tree stmt)
+{
+ switch (NUM_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES))
+ {
+ case 0:
+ gcc_unreachable ();
+
+ case 1:
+ {
+ tree def_stmt = SSA_NAME_DEF_STMT (SINGLE_SSA_TREE_OPERAND
+ (stmt, SSA_OP_VIRTUAL_USES));
+ /* We can handle lookups over PHI nodes only for a single
+ virtual operand. */
+ if (TREE_CODE (def_stmt) == PHI_NODE)
+ return get_single_def_stmt_from_phi (ref, def_stmt);
+ return def_stmt;
+ }
+
+ default:
+ return get_single_def_stmt (stmt);
+ }
+}
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