+/* Describe size of loop as detected by tree_estimate_loop_size. */
+struct loop_size
+{
+ /* Number of instructions in the loop. */
+ int overall;
+
+ /* Number of instructions that will be likely optimized out in
+ peeled iterations of loop (i.e. computation based on induction
+ variable where induction variable starts at known constant.) */
+ int eliminated_by_peeling;
+
+ /* Same statistics for last iteration of loop: it is smaller because
+ instructions after exit are not executed. */
+ int last_iteration;
+ int last_iteration_eliminated_by_peeling;
+};
+
+/* Return true if OP in STMT will be constant after peeling LOOP. */
+
+static bool
+constant_after_peeling (tree op, gimple stmt, struct loop *loop)
+{
+ affine_iv iv;
+
+ if (is_gimple_min_invariant (op))
+ return true;
+
+ /* We can still fold accesses to constant arrays when index is known. */
+ if (TREE_CODE (op) != SSA_NAME)
+ {
+ tree base = op;
+
+ /* First make fast look if we see constant array inside. */
+ while (handled_component_p (base))
+ base = TREE_OPERAND (base, 0);
+ if ((DECL_P (base)
+ && TREE_STATIC (base)
+ && TREE_READONLY (base)
+ && (DECL_INITIAL (base)
+ || (!DECL_EXTERNAL (base)
+ && targetm.binds_local_p (base))))
+ || CONSTANT_CLASS_P (base))
+ {
+ /* If so, see if we understand all the indices. */
+ base = op;
+ while (handled_component_p (base))
+ {
+ if (TREE_CODE (base) == ARRAY_REF
+ && !constant_after_peeling (TREE_OPERAND (base, 1), stmt, loop))
+ return false;
+ base = TREE_OPERAND (base, 0);
+ }
+ return true;
+ }
+ return false;
+ }
+
+ /* Induction variables are constants. */
+ if (!simple_iv (loop, loop_containing_stmt (stmt), op, &iv, false))
+ return false;
+ if (!is_gimple_min_invariant (iv.base))
+ return false;
+ if (!is_gimple_min_invariant (iv.step))
+ return false;
+ return true;
+}
+
+/* Computes an estimated number of insns in LOOP, weighted by WEIGHTS.
+ Return results in SIZE, estimate benefits for complete unrolling exiting by EXIT. */
+
+static void
+tree_estimate_loop_size (struct loop *loop, edge exit, struct loop_size *size)
+{
+ basic_block *body = get_loop_body (loop);
+ gimple_stmt_iterator gsi;
+ unsigned int i;
+ bool after_exit;
+
+ size->overall = 0;
+ size->eliminated_by_peeling = 0;
+ size->last_iteration = 0;
+ size->last_iteration_eliminated_by_peeling = 0;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Estimating sizes for loop %i\n", loop->num);
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ if (exit && body[i] != exit->src
+ && dominated_by_p (CDI_DOMINATORS, body[i], exit->src))
+ after_exit = true;
+ else
+ after_exit = false;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " BB: %i, after_exit: %i\n", body[i]->index, after_exit);
+
+ for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ int num = estimate_num_insns (stmt, &eni_size_weights);
+ bool likely_eliminated = false;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " size: %3i ", num);
+ print_gimple_stmt (dump_file, gsi_stmt (gsi), 0, 0);
+ }
+
+ /* Look for reasons why we might optimize this stmt away. */
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