2 * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Perform optimizations of the type representation.
24 * @author Goetz Lindenmaier
31 #include "iroptimize.h"
33 #include "irtypeinfo.h"
43 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
45 /* - statistics ---------------------------------------------- */
47 static size_t n_casts_normalized = 0;
48 static size_t n_casts_removed = 0;
49 static size_t n_sels_concretized = 0;
51 /* - Cast normalization. ------------------------------------- */
53 static ir_type *default_gen_pointer_type_to(ir_type *tp);
55 #define PTR_TYPE_SUFFIX "cc_ptr_tp" /* class cast pointer type. */
56 static ident *ptr_type_suffix = NULL;
57 static gen_pointer_type_to_func gen_pointer_type_to = default_gen_pointer_type_to;
60 * Find a pointer type to a given type.
61 * Uses and updates trouts if available.
63 static ir_type *default_gen_pointer_type_to(ir_type *tp)
66 if (get_trouts_state() == outs_consistent) {
67 if (get_type_n_pointertypes_to(tp) > 0) {
68 res = get_type_pointertype_to(tp, 0);
70 res = new_type_pointer(tp);
71 /* Update trout for pointer types, so we can use it in next call. */
72 add_type_pointertype_to(tp, res);
75 res = find_pointer_type_to_type(tp);
76 if (res == firm_unknown_type)
77 res = new_type_pointer(tp);
83 /** Return a type that is a depth times pointer to type. */
84 static ir_type *pointerize_type(ir_type *tp, size_t depth)
86 for (; depth > 0; --depth) {
87 tp = gen_pointer_type_to(tp);
93 static ir_node *normalize_values_type(ir_type *totype, ir_node *pred)
95 ir_type *fromtype = get_irn_typeinfo_type(pred);
96 ir_node *new_cast = pred;
100 if (totype == fromtype) return pred; /* Case for optimization! */
102 while (is_Pointer_type(totype) && is_Pointer_type(fromtype)) {
103 totype = get_pointer_points_to_type(totype);
104 fromtype = get_pointer_points_to_type(fromtype);
108 if (!is_Class_type(totype)) return pred;
109 if (!is_Class_type(fromtype)) return pred;
111 if ((get_class_supertype_index(totype, fromtype) != (size_t)-1) ||
112 (get_class_supertype_index(fromtype, totype) != (size_t)-1) ) {
113 /* It's just what we want ... */
117 block = get_nodes_block(pred);
119 if (is_SubClass_of(totype, fromtype)) {
121 while (get_class_subtype_index(fromtype, totype) == (size_t)-1) {
122 /* Insert a cast to a subtype of fromtype. */
123 ir_type *new_type = NULL;
126 size_t n_subtypes = get_class_n_subtypes(fromtype);
127 for (i = 0; i < n_subtypes && !new_type; ++i) {
128 ir_type *new_sub = get_class_subtype(fromtype, i);
129 if (is_SuperClass_of(new_sub, totype))
134 new_type = pointerize_type(new_type, ref_depth);
135 new_cast = new_r_Cast(block, pred, new_type);
137 ++n_casts_normalized;
138 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
139 if (get_trouts_state() != outs_none) add_type_cast(new_type, new_cast);
142 assert(is_SuperClass_of(totype, fromtype));
144 while (get_class_supertype_index(fromtype, totype) == (size_t)-1) {
145 /* Insert a cast to a supertype of fromtype. */
146 ir_type *new_type = NULL;
147 size_t i, n_supertypes = get_class_n_supertypes(fromtype);
148 for (i = 0; i < n_supertypes && !new_type; ++i) {
149 ir_type *new_super = get_class_supertype(fromtype, i);
150 if (is_SubClass_of(new_super, totype))
151 new_type = new_super;
155 new_type = pointerize_type(new_type, ref_depth);
156 new_cast = new_r_Cast(block, pred, new_type);
158 ++n_casts_normalized;
159 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
160 if (get_trouts_state() != outs_none) add_type_cast(new_type, new_cast);
169 static void normalize_irn_class_cast(ir_node *n, void *env)
174 ir_node *pred = get_Cast_op(n);
175 ir_type *totype = get_Cast_type(n);
176 res = normalize_values_type(totype, pred);
178 } else if (is_Call(n)) {
179 size_t n_params = get_Call_n_params(n);
181 ir_type *tp = get_Call_type(n);
182 for (i = 0; i < n_params; ++i) {
183 res = normalize_values_type(get_method_param_type(tp, i), get_Call_param(n, i));
184 set_Call_param(n, i, res);
190 static void pure_normalize_irg_class_casts(ir_graph *irg)
192 assert(get_irg_class_cast_state(irg) != ir_class_casts_any &&
193 "Cannot normalize irregular casts.");
194 if (get_irg_class_cast_state(irg) == ir_class_casts_normalized) {
195 verify_irg_class_cast_state(irg);
199 irg_walk_graph(irg, NULL, normalize_irn_class_cast, NULL);
200 set_irg_class_cast_state(irg, ir_class_casts_normalized);
204 void normalize_irg_class_casts(ir_graph *irg, gen_pointer_type_to_func gppt_fct)
206 assert(get_irp_typeinfo_state() == ir_typeinfo_consistent);
208 if (gppt_fct) gen_pointer_type_to = gppt_fct;
210 if (!ptr_type_suffix)
211 ptr_type_suffix = new_id_from_str(PTR_TYPE_SUFFIX);
213 pure_normalize_irg_class_casts(irg);
215 gen_pointer_type_to = default_gen_pointer_type_to;
218 void normalize_irp_class_casts(gen_pointer_type_to_func gppt_fct)
221 if (gppt_fct) gen_pointer_type_to = gppt_fct;
224 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
225 simple_analyse_types();
228 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
229 ir_graph *irg = get_irp_irg(i);
230 pure_normalize_irg_class_casts(irg);
233 set_irp_class_cast_state(ir_class_casts_normalized);
234 gen_pointer_type_to = default_gen_pointer_type_to;
236 DB((dbg, SET_LEVEL_1, " Cast normalization: %zu Casts inserted.\n", n_casts_normalized));
241 /* - Cast optimization. ------------------------------------------- */
246 * (T1)(T2)x<T1> -> x<T1>
248 * (T3)(T2)x<T1> -> (T3)x<T1>
252 * @param cast the Cast node
254 * @return 1 if the cast was changed
256 static int cancel_out_casts(ir_node *cast)
258 ir_node *orig, *pred = get_Cast_op(cast);
259 ir_type *tp_cast, *tp_pred, *tp_orig;
261 if (!is_Cast(pred)) return 0;
262 orig = get_Cast_op(pred);
264 tp_cast = get_Cast_type(cast);
265 tp_pred = get_Cast_type(pred);
266 tp_orig = get_irn_typeinfo_type(orig);
268 while (is_Pointer_type(tp_cast) &&
269 is_Pointer_type(tp_pred) &&
270 is_Pointer_type(tp_orig) ) {
271 tp_cast = get_pointer_points_to_type(tp_cast);
272 tp_pred = get_pointer_points_to_type(tp_pred);
273 tp_orig = get_pointer_points_to_type(tp_orig);
276 if (!is_Class_type(tp_cast) || !is_Class_type(tp_pred) || !is_Class_type(tp_orig))
279 if (is_SubClass_of(tp_pred, tp_cast) && get_opt_suppress_downcast_optimization())
282 if (tp_cast == tp_orig) {
283 exchange(cast, orig);
284 n_casts_removed += 2;
288 if (!(is_SubClass_of (tp_cast, tp_orig) || is_SubClass_of (tp_orig, tp_cast))) {
289 /* Avoid (B2)(A)(new B1()) --> (B2)(new B1())
290 * if B1 =!> B2 and B2 =!> B1
295 if ((is_SubClass_of (tp_cast, tp_pred) && is_SuperClass_of(tp_pred, tp_orig)) ||
296 (is_SuperClass_of(tp_cast, tp_pred) && is_SubClass_of (tp_pred, tp_orig))) {
297 /* Cast --> Pred --> Orig */
298 set_Cast_op(cast, orig);
306 * Optimize Sel(Cast(type, ptr), ent) into Sel(ptr_type, ent_type)
308 * @param sel the Sel node
310 * @return 1 if Cast's where removed
312 static int concretize_selected_entity(ir_node *sel)
314 ir_node *cast, *ptr = get_Sel_ptr(sel);
315 ir_type *orig_tp, *cast_tp;
316 ir_entity *new_ent, *sel_ent;
319 sel_ent = get_Sel_entity(sel);
320 cast = get_Sel_ptr(sel);
322 while (is_Cast(cast)) {
323 cast_tp = get_Cast_type(cast);
324 ptr = get_Cast_op(cast);
325 orig_tp = get_irn_typeinfo_type(ptr);
327 /* we handle only classes */
328 if (!is_Pointer_type(orig_tp)|| !is_Pointer_type(cast_tp))
330 orig_tp = get_pointer_points_to_type(orig_tp);
331 cast_tp = get_pointer_points_to_type(cast_tp);
332 if (!is_Class_type(orig_tp) || !is_Class_type(cast_tp))
335 /* We only want to concretize, but not generalize. */
336 if (!is_SuperClass_of(cast_tp, orig_tp))
339 /* The sel entity should be a member of the cast_tp, else
340 the graph was not properly typed. */
341 if (get_class_member_index(cast_tp, sel_ent) == (size_t)-1)
344 new_ent = resolve_ent_polymorphy(orig_tp, sel_ent);
346 /* New ent must be member of orig_tp. */
347 if (get_class_member_index(orig_tp, new_ent) == (size_t)-1)
350 /* all checks done, we can remove the Cast and update the Sel */
351 set_Sel_entity(sel, new_ent);
352 set_Sel_ptr(sel, ptr);
353 ++n_sels_concretized;
363 * Move Casts of the same type through a Phi node, i.e.
364 * Phi(Cast(type, x_0), ..., Cast(type, x_n)) -> Cast(type, Phi(x_0, ..., x_n))
366 * @param phi the Phi node
368 * @return 1 if Cast's where moved
370 static int concretize_Phi_type(ir_node *phi)
372 int n_preds = get_Phi_n_preds(phi);
373 ir_node **pred = ALLOCAN(ir_node*, n_preds);
381 pred[0] = get_Phi_pred(phi, 0);
383 if (!is_Cast(pred[0]))
386 if (!is_Cast_upcast(pred[0]))
389 fromtype = get_irn_typeinfo_type(get_Cast_op(pred[0]));
390 totype = get_Cast_type(pred[0]);
392 pred[0] = get_Cast_op(pred[0]);
393 for (i = 1; i < n_preds; ++i) {
394 pred[i] = get_Phi_pred(phi, i);
395 if (!is_Cast(pred[i]))
397 if (get_irn_typeinfo_type(get_Cast_op(pred[i])) != fromtype)
399 pred[i] = get_Cast_op(pred[i]);
403 blk = get_nodes_block(phi);
404 nn = new_r_Phi(blk, n_preds, pred, get_irn_mode(phi));
405 set_irn_typeinfo_type(nn, fromtype);
406 nn = new_r_Cast(blk, nn, totype);
407 set_irn_typeinfo_type(nn, totype);
413 * Remove Casted null checks, i.e.
415 * Cmp(Cast(type, x_orig), NULL_type) -> Cmp(x_orig, NULL_orig)
417 * @param cmp the Cmp node
419 * @return 1 if Cast's where removed
421 static int remove_Cmp_Null_cast(ir_node *cmp)
424 ir_node *cast, *null, *new_null;
425 int cast_pos, null_pos;
429 cast = get_Cmp_left(cmp);
430 if (!is_Cast(cast)) {
433 cast = get_Cmp_right(cmp);
438 null = get_Cmp_right(cmp);
443 if (! is_Const(null))
445 mode = get_irn_mode(null);
446 if (!mode_is_reference(mode))
448 if (get_Const_tarval(null) != get_mode_null(mode))
452 irg = get_irn_irg(cmp);
453 set_irn_n(cmp, cast_pos, get_Cast_op(cast));
454 fromtype = get_irn_typeinfo_type(get_Cast_op(cast));
455 new_null = new_r_Const(irg, get_Const_tarval(null));
456 set_irn_typeinfo_type(new_null, fromtype);
457 set_irn_n(cmp, null_pos, new_null);
463 * Post-Walker: Optimize class casts (mostly by trying to remove them)
465 static void irn_optimize_class_cast(ir_node *n, void *env)
467 int *changed = (int*)env;
470 *changed |= cancel_out_casts(n);
472 *changed |= concretize_selected_entity(n);
474 *changed |= concretize_Phi_type(n);
476 *changed |= remove_Cmp_Null_cast(n);
479 void optimize_class_casts(void)
484 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
485 simple_analyse_types();
489 all_irg_walk(NULL, irn_optimize_class_cast, &changed);
492 set_trouts_inconsistent();
495 DB((dbg, SET_LEVEL_1, " Cast optimization: %zu Casts removed, %zu Sels concretized.\n",
496 n_casts_removed, n_sels_concretized));
499 void firm_init_class_casts_opt(void)
501 FIRM_DBG_REGISTER(dbg, "firm.opt.tropt");