2 * Copyright (C) 1995-2008 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"
35 #include "irsimpletype.h"
44 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
46 /* - statistics ---------------------------------------------- */
48 static int n_casts_normalized = 0;
49 static int n_casts_removed = 0;
50 static int n_sels_concretized = 0;
52 /* - Cast normalization. ------------------------------------- */
54 static ir_type *default_gen_pointer_type_to(ir_type *tp);
56 #define PTR_TYPE_SUFFIX "cc_ptr_tp" /* class cast pointer type. */
57 static ident *ptr_type_suffix = NULL;
58 static gen_pointer_type_to_func gen_pointer_type_to = default_gen_pointer_type_to;
61 * Find a pointer type to a given type.
62 * Uses and updates trouts if available.
64 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 ir_mode *mode = is_Method_type(tp) ? mode_P_code : mode_P_data;
72 res = new_type_pointer(mangle_u(get_type_ident(tp), ptr_type_suffix), tp, mode);
73 /* Update trout for pointer types, so we can use it in next call. */
74 add_type_pointertype_to(tp, res);
78 res = find_pointer_type_to_type(tp);
79 if (res == firm_unknown_type)
80 res = new_type_pointer(mangle_u(get_type_ident(tp), ptr_type_suffix), tp, mode_P_data);
86 /** Return a type that is a depth times pointer to type. */
87 static ir_type *pointerize_type(ir_type *tp, int depth) {
88 for (; depth > 0; --depth) {
89 tp = gen_pointer_type_to(tp);
95 static ir_node *normalize_values_type(ir_type *totype, ir_node *pred) {
96 ir_type *fromtype = get_irn_typeinfo_type(pred);
97 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) != -1) ||
112 (get_class_supertype_index(fromtype, totype) != -1) ) {
113 /* It's just what we want ... */
117 set_cur_block(get_nodes_block(pred));
119 if (is_SubClass_of(totype, fromtype)) {
121 while (get_class_subtype_index(fromtype, totype) == -1) {
122 /* Insert a cast to a subtype of fromtype. */
123 ir_type *new_type = NULL;
125 int i, n_subtypes = get_class_n_subtypes(fromtype);
126 for (i = 0; i < n_subtypes && !new_type; ++i) {
127 ir_type *new_sub = get_class_subtype(fromtype, i);
128 if (is_SuperClass_of(new_sub, totype))
133 new_type = pointerize_type(new_type, ref_depth);
134 new_cast = new_Cast(pred, new_type);
136 n_casts_normalized ++;
137 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
138 if (get_trouts_state() != outs_none) add_type_cast(new_type, new_cast);
141 assert(is_SuperClass_of(totype, fromtype));
143 while (get_class_supertype_index(fromtype, totype) == -1) {
144 /* Insert a cast to a supertype of fromtype. */
145 ir_type *new_type = NULL;
146 int i, n_supertypes = get_class_n_supertypes(fromtype);
147 for (i = 0; i < n_supertypes && !new_type; ++i) {
148 ir_type *new_super = get_class_supertype(fromtype, i);
149 if (is_SubClass_of(new_super, totype))
150 new_type = new_super;
154 new_type = pointerize_type(new_type, ref_depth);
155 new_cast = new_Cast(pred, new_type);
157 n_casts_normalized ++;
158 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
159 if (get_trouts_state() != outs_none) add_type_cast(new_type, new_cast);
168 static void normalize_irn_class_cast(ir_node *n, void *env) {
172 ir_node *pred = get_Cast_op(n);
173 ir_type *totype = get_Cast_type(n);
174 res = normalize_values_type(totype, pred);
176 } else if (is_Call(n)) {
177 int i, n_params = get_Call_n_params(n);
178 ir_type *tp = get_Call_type(n);
179 for (i = 0; i < n_params; ++i) {
180 res = normalize_values_type(get_method_param_type(tp, i), get_Call_param(n, i));
181 set_Call_param(n, i, res);
187 static void pure_normalize_irg_class_casts(ir_graph *irg) {
188 assert(get_irg_class_cast_state(irg) != ir_class_casts_any &&
189 "Cannot normalize irregular casts.");
190 if (get_irg_class_cast_state(irg) == ir_class_casts_normalized) {
191 verify_irg_class_cast_state(irg);
195 irg_walk_graph(irg, NULL, normalize_irn_class_cast, NULL);
196 set_irg_class_cast_state(irg, ir_class_casts_normalized);
200 void normalize_irg_class_casts(ir_graph *irg, gen_pointer_type_to_func gppt_fct) {
201 assert(get_irp_typeinfo_state() == ir_typeinfo_consistent);
203 if (gppt_fct) gen_pointer_type_to = gppt_fct;
205 if (!ptr_type_suffix)
206 ptr_type_suffix = new_id_from_str(PTR_TYPE_SUFFIX);
208 pure_normalize_irg_class_casts(irg);
210 gen_pointer_type_to = default_gen_pointer_type_to;
213 void normalize_irp_class_casts(gen_pointer_type_to_func gppt_fct) {
214 int i, n_irgs = get_irp_n_irgs();
215 if (gppt_fct) gen_pointer_type_to = gppt_fct;
217 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
218 simple_analyse_types();
220 for (i = 0; i < n_irgs; ++i) {
221 pure_normalize_irg_class_casts(get_irp_irg(i));
224 set_irp_class_cast_state(ir_class_casts_normalized);
225 gen_pointer_type_to = default_gen_pointer_type_to;
227 DB((dbg, SET_LEVEL_1, " Cast normalization: %d Casts inserted.\n", n_casts_normalized));
232 /* - Cast optimization. ------------------------------------------- */
237 * (T1)(T2)x<T1> -> x<T1>
239 * (T3)(T2)x<T1> -> (T3)x<T1>
243 static void cancel_out_casts(ir_node *cast) {
244 ir_node *orig, *pred = get_Cast_op(cast);
245 ir_type *tp_cast, *tp_pred, *tp_orig;
248 if (!is_Cast(pred)) return;
249 orig = get_Cast_op(pred);
251 tp_cast = get_Cast_type(cast);
252 tp_pred = get_Cast_type(pred);
253 tp_orig = get_irn_typeinfo_type(orig);
255 while (is_Pointer_type(tp_cast) &&
256 is_Pointer_type(tp_pred) &&
257 is_Pointer_type(tp_orig) ) {
258 tp_cast = get_pointer_points_to_type(tp_cast);
259 tp_pred = get_pointer_points_to_type(tp_pred);
260 tp_orig = get_pointer_points_to_type(tp_orig);
264 if (!is_Class_type(tp_cast)) return;
265 if (!is_Class_type(tp_pred)) return;
266 if (!is_Class_type(tp_orig)) return;
268 if (is_SubClass_of(tp_pred, tp_cast) && get_opt_suppress_downcast_optimization())
271 if (tp_cast == tp_orig) {
272 exchange(cast, orig);
273 n_casts_removed += 2;
277 if (!(is_SubClass_of (tp_cast, tp_orig) || is_SubClass_of (tp_orig, tp_cast))) {
278 /* Avoid (B2)(A)(new B1()) --> (B2)(new B1())
279 * if B1 =!> B2 and B2 =!> B1
284 if ((is_SubClass_of (tp_cast, tp_pred) && is_SuperClass_of(tp_pred, tp_orig)) ||
285 (is_SuperClass_of(tp_cast, tp_pred) && is_SubClass_of (tp_pred, tp_orig))) {
286 /* Cast --> Pred --> Orig */
287 set_Cast_op(cast, orig);
292 static void concretize_selected_entity(ir_node *sel) {
293 ir_node *cast, *ptr = get_Sel_ptr(sel);
294 ir_type *orig_tp, *cast_tp;
295 ir_entity *new_ent, *sel_ent;
297 sel_ent = get_Sel_entity(sel);
298 cast = get_Sel_ptr(sel);
300 while (is_Cast(cast)) {
301 cast_tp = get_Cast_type(cast);
302 ptr = get_Cast_op(cast);
303 orig_tp = get_irn_typeinfo_type(ptr);
305 if (!is_Pointer_type(orig_tp)) return;
306 if (!is_Pointer_type(cast_tp)) return;
307 orig_tp = get_pointer_points_to_type(orig_tp);
308 cast_tp = get_pointer_points_to_type(cast_tp);
309 if (!is_Class_type(orig_tp)) return;
310 if (!is_Class_type(cast_tp)) return;
312 /* We only want to concretize, but not generalize. */
313 if (!is_SuperClass_of(cast_tp, orig_tp)) return;
315 /* Hmm, we are not properly typed. */
316 if (get_class_member_index(cast_tp, sel_ent) == -1) return;
318 new_ent = resolve_ent_polymorphy(orig_tp, sel_ent);
320 /* New ent must be member of orig_tp. */
321 if (get_class_member_index(orig_tp, new_ent) == -1) return;
323 set_Sel_entity(sel, new_ent);
324 set_Sel_ptr(sel, ptr);
325 n_sels_concretized++;
332 static void concretize_Phi_type(ir_node *phi)
334 int n_preds = get_Phi_n_preds(phi);
335 ir_node **pred = ALLOCAN(ir_node*, n_preds);
341 if (n_preds == 0) return;
342 pred[0] = get_Phi_pred(phi, 0);
344 if (!is_Cast(pred[0])) return;
346 if (!is_Cast_upcast(pred[0])) return;
348 fromtype = get_irn_typeinfo_type(get_Cast_op(pred[0]));
349 totype = get_Cast_type(pred[0]);
351 pred[0] = get_Cast_op(pred[0]);
352 for (i = 1; i < n_preds; ++i) {
353 pred[i] = get_Phi_pred(phi, i);
354 if (!is_Cast(pred[i])) return;
355 if (get_irn_typeinfo_type(get_Cast_op(pred[i])) != fromtype) return;
356 pred[i] = get_Cast_op(pred[i]);
360 set_cur_block(get_nodes_block(phi));
361 nn = new_Phi(n_preds, pred, get_irn_mode(phi));
362 set_irn_typeinfo_type(nn, fromtype);
363 nn = new_Cast(nn, totype);
364 set_irn_typeinfo_type(nn, totype);
368 void remove_Cmp_Null_cast(ir_node *cmp) {
369 ir_node *cast, *null, *new_null;
370 int cast_pos, null_pos;
373 cast = get_Cmp_left(cmp);
375 if (!is_Cast(cast)) {
378 cast = get_Cmp_right(cmp);
380 if (!is_Cast(cast)) return;
382 null = get_Cmp_right(cmp);
386 if (! is_Const(null)) return;
387 if (!mode_is_reference(get_irn_mode(null))) return;
388 if (get_Const_tarval(null) != get_mode_null(get_irn_mode(null))) return;
391 set_irn_n(cmp, cast_pos, get_Cast_op(cast));
392 fromtype = get_irn_typeinfo_type(get_Cast_op(cast));
393 new_null = new_Const_type(get_Const_tarval(null), fromtype);
394 set_irn_typeinfo_type(new_null, fromtype);
395 set_irn_n(cmp, null_pos, new_null);
402 static void irn_optimize_class_cast(ir_node *n, void *env) {
407 concretize_selected_entity(n);
409 concretize_Phi_type(n);
411 remove_Cmp_Null_cast(n);
414 void optimize_class_casts(void) {
415 int i, n_irgs = get_irp_n_irgs();
417 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
418 simple_analyse_types();
420 all_irg_walk(NULL, irn_optimize_class_cast, NULL);
422 set_trouts_inconsistent();
423 for (i = 0; i < n_irgs; ++i)
424 set_irg_outs_inconsistent(get_irp_irg(i));
426 DB((dbg, SET_LEVEL_1, " Cast optimization: %d Casts removed, %d Sels concretized.\n",
427 n_casts_removed, n_sels_concretized));
430 void firm_init_class_casts_opt(void) {
431 FIRM_DBG_REGISTER(dbg, "firm.opt.tropt");