- bitmap visited = BITMAP_XMALLOC ();
- walk_use_def_chains_1 (var, fn, data, visited);
- BITMAP_XFREE (visited);
- }
-}
-
-/* Replaces VAR with REPL in memory reference expression *X in
- statement STMT. */
-
-static void
-propagate_into_addr (tree stmt, tree var, tree *x, tree repl)
-{
- tree new_var, ass_stmt, addr_var;
- basic_block bb;
- block_stmt_iterator bsi;
-
- /* There is nothing special to handle in the other cases. */
- if (TREE_CODE (repl) != ADDR_EXPR)
- return;
- addr_var = TREE_OPERAND (repl, 0);
-
- while (TREE_CODE (*x) == ARRAY_REF
- || TREE_CODE (*x) == COMPONENT_REF
- || TREE_CODE (*x) == BIT_FIELD_REF)
- x = &TREE_OPERAND (*x, 0);
-
- if (TREE_CODE (*x) != INDIRECT_REF
- || TREE_OPERAND (*x, 0) != var)
- return;
-
- modify_stmt (stmt);
- if (TREE_TYPE (*x) == TREE_TYPE (addr_var))
- {
- *x = addr_var;
- mark_new_vars_to_rename (stmt, vars_to_rename);
- return;
- }
-
- /* Frontends sometimes produce expressions like *&a instead of a[0].
- Create a temporary variable to handle this case. */
- ass_stmt = build2 (MODIFY_EXPR, void_type_node, NULL_TREE, repl);
- new_var = duplicate_ssa_name (var, ass_stmt);
- TREE_OPERAND (*x, 0) = new_var;
- TREE_OPERAND (ass_stmt, 0) = new_var;
-
- bb = bb_for_stmt (stmt);
- tree_block_label (bb);
- bsi = bsi_after_labels (bb);
- bsi_insert_after (&bsi, ass_stmt, BSI_NEW_STMT);
-
- mark_new_vars_to_rename (stmt, vars_to_rename);
-}
-
-/* Replaces immediate uses of VAR by REPL. */
-
-static void
-replace_immediate_uses (tree var, tree repl)
-{
- use_optype uses;
- vuse_optype vuses;
- v_may_def_optype v_may_defs;
- int i, j, n;
- dataflow_t df;
- tree stmt;
- stmt_ann_t ann;
- bool mark_new_vars;
-
- df = get_immediate_uses (SSA_NAME_DEF_STMT (var));
- n = num_immediate_uses (df);
-
- for (i = 0; i < n; i++)
- {
- stmt = immediate_use (df, i);
- ann = stmt_ann (stmt);
-
- if (TREE_CODE (stmt) == PHI_NODE)
- {
- for (j = 0; j < PHI_NUM_ARGS (stmt); j++)
- if (PHI_ARG_DEF (stmt, j) == var)
- {
- SET_PHI_ARG_DEF (stmt, j, repl);
- if (TREE_CODE (repl) == SSA_NAME
- && PHI_ARG_EDGE (stmt, j)->flags & EDGE_ABNORMAL)
- SSA_NAME_OCCURS_IN_ABNORMAL_PHI (repl) = 1;
- }
-
- continue;
- }
-
- get_stmt_operands (stmt);
- mark_new_vars = false;
- if (is_gimple_reg (SSA_NAME_VAR (var)))
- {
- if (TREE_CODE (stmt) == MODIFY_EXPR)
- {
- propagate_into_addr (stmt, var, &TREE_OPERAND (stmt, 0), repl);
- propagate_into_addr (stmt, var, &TREE_OPERAND (stmt, 1), repl);
- }
-
- uses = USE_OPS (ann);
- for (j = 0; j < (int) NUM_USES (uses); j++)
- if (USE_OP (uses, j) == var)
- {
- propagate_value (USE_OP_PTR (uses, j), repl);
- mark_new_vars = POINTER_TYPE_P (TREE_TYPE (repl));
- }
- }
- else
- {
- vuses = VUSE_OPS (ann);
- for (j = 0; j < (int) NUM_VUSES (vuses); j++)
- if (VUSE_OP (vuses, j) == var)
- propagate_value (VUSE_OP_PTR (vuses, j), repl);
-
- v_may_defs = V_MAY_DEF_OPS (ann);
- for (j = 0; j < (int) NUM_V_MAY_DEFS (v_may_defs); j++)
- if (V_MAY_DEF_OP (v_may_defs, j) == var)
- propagate_value (V_MAY_DEF_OP_PTR (v_may_defs, j), repl);
- }
-
- /* If REPL is a pointer, it may have different memory tags associated
- with it. For instance, VAR may have had a name tag while REPL
- only had a type tag. In these cases, the virtual operands (if
- any) in the statement will refer to different symbols which need
- to be renamed. */
- if (mark_new_vars)
- mark_new_vars_to_rename (stmt, vars_to_rename);
- else
- modify_stmt (stmt);
- }
-}
-
-/* Gets the value VAR is equivalent to according to EQ_TO. */
-
-static tree
-get_eq_name (tree *eq_to, tree var)
-{
- unsigned ver;
- tree val = var;
-
- while (TREE_CODE (val) == SSA_NAME)
- {
- ver = SSA_NAME_VERSION (val);
- if (!eq_to[ver])
- break;
-
- val = eq_to[ver];
- }
-
- while (TREE_CODE (var) == SSA_NAME)
- {
- ver = SSA_NAME_VERSION (var);
- if (!eq_to[ver])
- break;
-
- var = eq_to[ver];
- eq_to[ver] = val;
- }
-
- return val;
-}
-
-/* Checks whether phi node PHI is redundant and if it is, records the ssa name
- its result is redundant to to EQ_TO array. */
-
-static void
-check_phi_redundancy (tree phi, tree *eq_to)
-{
- tree val = NULL_TREE, def, res = PHI_RESULT (phi), stmt;
- unsigned i, ver = SSA_NAME_VERSION (res), n;
- dataflow_t df;
-
- /* It is unlikely that such large phi node would be redundant. */
- if (PHI_NUM_ARGS (phi) > 16)
- return;
-
- for (i = 0; i < (unsigned) PHI_NUM_ARGS (phi); i++)
- {
- def = PHI_ARG_DEF (phi, i);
-
- if (TREE_CODE (def) == SSA_NAME)
- {
- def = get_eq_name (eq_to, def);
- if (def == res)
- continue;
- }
-
- if (val
- && !operand_equal_p (val, def, 0))
- return;
-
- val = def;
- }
-
- /* At least one of the arguments should not be equal to the result, or
- something strange is happening. */
- if (!val)
- abort ();
-
- if (get_eq_name (eq_to, res) == val)
- return;
-
- if (!may_propagate_copy (res, val))
- return;
-
- eq_to[ver] = val;
-
- df = get_immediate_uses (SSA_NAME_DEF_STMT (res));
- n = num_immediate_uses (df);
-
- for (i = 0; i < n; i++)
- {
- stmt = immediate_use (df, i);
-
- if (TREE_CODE (stmt) == PHI_NODE)
- check_phi_redundancy (stmt, eq_to);