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)
65 ir_type *res = find_pointer_type_to_type(tp);
66 if (res == firm_unknown_type)
67 res = new_type_pointer(tp);
72 /** Return a type that is a depth times pointer to type. */
73 static ir_type *pointerize_type(ir_type *tp, size_t depth)
75 for (; depth > 0; --depth) {
76 tp = gen_pointer_type_to(tp);
82 static ir_node *normalize_values_type(ir_type *totype, ir_node *pred)
84 ir_type *fromtype = get_irn_typeinfo_type(pred);
85 ir_node *new_cast = pred;
89 if (totype == fromtype) return pred; /* Case for optimization! */
91 while (is_Pointer_type(totype) && is_Pointer_type(fromtype)) {
92 totype = get_pointer_points_to_type(totype);
93 fromtype = get_pointer_points_to_type(fromtype);
97 if (!is_Class_type(totype)) return pred;
98 if (!is_Class_type(fromtype)) return pred;
100 if ((get_class_supertype_index(totype, fromtype) != (size_t)-1) ||
101 (get_class_supertype_index(fromtype, totype) != (size_t)-1) ) {
102 /* It's just what we want ... */
106 block = get_nodes_block(pred);
108 if (is_SubClass_of(totype, fromtype)) {
110 while (get_class_subtype_index(fromtype, totype) == (size_t)-1) {
111 /* Insert a cast to a subtype of fromtype. */
112 ir_type *new_type = NULL;
115 size_t n_subtypes = get_class_n_subtypes(fromtype);
116 for (i = 0; i < n_subtypes && !new_type; ++i) {
117 ir_type *new_sub = get_class_subtype(fromtype, i);
118 if (is_SuperClass_of(new_sub, totype))
123 new_type = pointerize_type(new_type, ref_depth);
124 new_cast = new_r_Cast(block, pred, new_type);
126 ++n_casts_normalized;
127 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
130 assert(is_SuperClass_of(totype, fromtype));
132 while (get_class_supertype_index(fromtype, totype) == (size_t)-1) {
133 /* Insert a cast to a supertype of fromtype. */
134 ir_type *new_type = NULL;
135 size_t i, n_supertypes = get_class_n_supertypes(fromtype);
136 for (i = 0; i < n_supertypes && !new_type; ++i) {
137 ir_type *new_super = get_class_supertype(fromtype, i);
138 if (is_SubClass_of(new_super, totype))
139 new_type = new_super;
143 new_type = pointerize_type(new_type, ref_depth);
144 new_cast = new_r_Cast(block, pred, new_type);
146 ++n_casts_normalized;
147 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
156 static void normalize_irn_class_cast(ir_node *n, void *env)
161 ir_node *pred = get_Cast_op(n);
162 ir_type *totype = get_Cast_type(n);
163 res = normalize_values_type(totype, pred);
165 } else if (is_Call(n)) {
166 size_t n_params = get_Call_n_params(n);
168 ir_type *tp = get_Call_type(n);
169 for (i = 0; i < n_params; ++i) {
170 res = normalize_values_type(get_method_param_type(tp, i), get_Call_param(n, i));
171 set_Call_param(n, i, res);
177 static void pure_normalize_irg_class_casts(ir_graph *irg)
179 assert(get_irg_class_cast_state(irg) != ir_class_casts_any &&
180 "Cannot normalize irregular casts.");
181 if (get_irg_class_cast_state(irg) == ir_class_casts_normalized) {
182 verify_irg_class_cast_state(irg);
186 irg_walk_graph(irg, NULL, normalize_irn_class_cast, NULL);
187 set_irg_class_cast_state(irg, ir_class_casts_normalized);
191 void normalize_irg_class_casts(ir_graph *irg, gen_pointer_type_to_func gppt_fct)
193 assert(get_irp_typeinfo_state() == ir_typeinfo_consistent);
195 if (gppt_fct) gen_pointer_type_to = gppt_fct;
197 if (!ptr_type_suffix)
198 ptr_type_suffix = new_id_from_str(PTR_TYPE_SUFFIX);
200 pure_normalize_irg_class_casts(irg);
202 gen_pointer_type_to = default_gen_pointer_type_to;
205 void normalize_irp_class_casts(gen_pointer_type_to_func gppt_fct)
208 if (gppt_fct) gen_pointer_type_to = gppt_fct;
211 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
212 simple_analyse_types();
215 for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
216 ir_graph *irg = get_irp_irg(i);
217 pure_normalize_irg_class_casts(irg);
220 set_irp_class_cast_state(ir_class_casts_normalized);
221 gen_pointer_type_to = default_gen_pointer_type_to;
223 DB((dbg, SET_LEVEL_1, " Cast normalization: %zu Casts inserted.\n", n_casts_normalized));
228 /* - Cast optimization. ------------------------------------------- */
233 * (T1)(T2)x<T1> -> x<T1>
235 * (T3)(T2)x<T1> -> (T3)x<T1>
239 * @param cast the Cast node
241 * @return 1 if the cast was changed
243 static int cancel_out_casts(ir_node *cast)
245 ir_node *orig, *pred = get_Cast_op(cast);
246 ir_type *tp_cast, *tp_pred, *tp_orig;
248 if (!is_Cast(pred)) return 0;
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);
263 if (!is_Class_type(tp_cast) || !is_Class_type(tp_pred) || !is_Class_type(tp_orig))
266 if (is_SubClass_of(tp_pred, tp_cast) && get_opt_suppress_downcast_optimization())
269 if (tp_cast == tp_orig) {
270 exchange(cast, orig);
271 n_casts_removed += 2;
275 if (!(is_SubClass_of (tp_cast, tp_orig) || is_SubClass_of (tp_orig, tp_cast))) {
276 /* Avoid (B2)(A)(new B1()) --> (B2)(new B1())
277 * if B1 =!> B2 and B2 =!> B1
282 if ((is_SubClass_of (tp_cast, tp_pred) && is_SuperClass_of(tp_pred, tp_orig)) ||
283 (is_SuperClass_of(tp_cast, tp_pred) && is_SubClass_of (tp_pred, tp_orig))) {
284 /* Cast --> Pred --> Orig */
285 set_Cast_op(cast, orig);
293 * Optimize Sel(Cast(type, ptr), ent) into Sel(ptr_type, ent_type)
295 * @param sel the Sel node
297 * @return 1 if Cast's where removed
299 static int concretize_selected_entity(ir_node *sel)
301 ir_node *cast, *ptr = get_Sel_ptr(sel);
302 ir_type *orig_tp, *cast_tp;
303 ir_entity *new_ent, *sel_ent;
306 sel_ent = get_Sel_entity(sel);
307 cast = get_Sel_ptr(sel);
309 while (is_Cast(cast)) {
310 cast_tp = get_Cast_type(cast);
311 ptr = get_Cast_op(cast);
312 orig_tp = get_irn_typeinfo_type(ptr);
314 /* we handle only classes */
315 if (!is_Pointer_type(orig_tp)|| !is_Pointer_type(cast_tp))
317 orig_tp = get_pointer_points_to_type(orig_tp);
318 cast_tp = get_pointer_points_to_type(cast_tp);
319 if (!is_Class_type(orig_tp) || !is_Class_type(cast_tp))
322 /* We only want to concretize, but not generalize. */
323 if (!is_SuperClass_of(cast_tp, orig_tp))
326 /* The sel entity should be a member of the cast_tp, else
327 the graph was not properly typed. */
328 if (get_class_member_index(cast_tp, sel_ent) == (size_t)-1)
331 new_ent = resolve_ent_polymorphy(orig_tp, sel_ent);
333 /* New ent must be member of orig_tp. */
334 if (get_class_member_index(orig_tp, new_ent) == (size_t)-1)
337 /* all checks done, we can remove the Cast and update the Sel */
338 set_Sel_entity(sel, new_ent);
339 set_Sel_ptr(sel, ptr);
340 ++n_sels_concretized;
350 * Move Casts of the same type through a Phi node, i.e.
351 * Phi(Cast(type, x_0), ..., Cast(type, x_n)) -> Cast(type, Phi(x_0, ..., x_n))
353 * @param phi the Phi node
355 * @return 1 if Cast's where moved
357 static int concretize_Phi_type(ir_node *phi)
359 int n_preds = get_Phi_n_preds(phi);
360 ir_node **pred = ALLOCAN(ir_node*, n_preds);
368 pred[0] = get_Phi_pred(phi, 0);
370 if (!is_Cast(pred[0]))
373 if (!is_Cast_upcast(pred[0]))
376 fromtype = get_irn_typeinfo_type(get_Cast_op(pred[0]));
377 totype = get_Cast_type(pred[0]);
379 pred[0] = get_Cast_op(pred[0]);
380 for (i = 1; i < n_preds; ++i) {
381 pred[i] = get_Phi_pred(phi, i);
382 if (!is_Cast(pred[i]))
384 if (get_irn_typeinfo_type(get_Cast_op(pred[i])) != fromtype)
386 pred[i] = get_Cast_op(pred[i]);
390 blk = get_nodes_block(phi);
391 nn = new_r_Phi(blk, n_preds, pred, get_irn_mode(phi));
392 set_irn_typeinfo_type(nn, fromtype);
393 nn = new_r_Cast(blk, nn, totype);
394 set_irn_typeinfo_type(nn, totype);
400 * Remove Casted null checks, i.e.
402 * Cmp(Cast(type, x_orig), NULL_type) -> Cmp(x_orig, NULL_orig)
404 * @param cmp the Cmp node
406 * @return 1 if Cast's where removed
408 static int remove_Cmp_Null_cast(ir_node *cmp)
411 ir_node *cast, *null, *new_null;
412 int cast_pos, null_pos;
416 cast = get_Cmp_left(cmp);
417 if (!is_Cast(cast)) {
420 cast = get_Cmp_right(cmp);
425 null = get_Cmp_right(cmp);
430 if (! is_Const(null))
432 mode = get_irn_mode(null);
433 if (!mode_is_reference(mode))
435 if (get_Const_tarval(null) != get_mode_null(mode))
439 irg = get_irn_irg(cmp);
440 set_irn_n(cmp, cast_pos, get_Cast_op(cast));
441 fromtype = get_irn_typeinfo_type(get_Cast_op(cast));
442 new_null = new_r_Const(irg, get_Const_tarval(null));
443 set_irn_typeinfo_type(new_null, fromtype);
444 set_irn_n(cmp, null_pos, new_null);
450 * Post-Walker: Optimize class casts (mostly by trying to remove them)
452 static void irn_optimize_class_cast(ir_node *n, void *env)
454 int *changed = (int*)env;
457 *changed |= cancel_out_casts(n);
459 *changed |= concretize_selected_entity(n);
461 *changed |= concretize_Phi_type(n);
463 *changed |= remove_Cmp_Null_cast(n);
466 void optimize_class_casts(void)
471 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
472 simple_analyse_types();
476 all_irg_walk(NULL, irn_optimize_class_cast, &changed);
478 DB((dbg, SET_LEVEL_1, " Cast optimization: %zu Casts removed, %zu Sels concretized.\n",
479 n_casts_removed, n_sels_concretized));
482 void firm_init_class_casts_opt(void)
484 FIRM_DBG_REGISTER(dbg, "firm.opt.tropt");