2 * Copyright (C) 1995-2007 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
33 #include "iroptimize.h"
35 #include "irtypeinfo.h"
37 #include "irsimpletype.h"
44 /* - statistics ---------------------------------------------- */
46 static int n_casts_normalized = 0;
47 static int n_casts_removed = 0;
48 static int n_sels_concretized = 0;
50 /* - Cast normalization. ------------------------------------- */
52 static ir_type *default_gen_pointer_type_to(ir_type *tp);
54 #define PTR_TYPE_SUFFIX "cc_ptr_tp" /* class cast pointer type. */
55 static ident *ptr_type_suffix = NULL;
56 static gen_pointer_type_to_func gen_pointer_type_to = default_gen_pointer_type_to;
59 * Find a pointer type to a given type.
60 * Uses and updates trouts if available.
62 static ir_type *default_gen_pointer_type_to(ir_type *tp) {
64 if (get_trouts_state() == outs_consistent) {
65 if (get_type_n_pointertypes_to(tp) > 0) {
66 res = get_type_pointertype_to(tp, 0);
68 ir_mode *mode = is_Method_type(tp) ? mode_P_code : mode_P_data;
70 res = new_type_pointer(mangle_u(get_type_ident(tp), ptr_type_suffix), tp, mode);
71 /* Update trout for pointer types, so we can use it in next call. */
72 add_type_pointertype_to(tp, res);
76 res = find_pointer_type_to_type(tp);
77 if (res == firm_unknown_type)
78 res = new_type_pointer(mangle_u(get_type_ident(tp), ptr_type_suffix), tp, mode_P_data);
84 /** Return a type that is a depth times pointer to type. */
85 static ir_type *pointerize_type(ir_type *tp, int 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) {
94 ir_type *fromtype = get_irn_typeinfo_type(pred);
95 ir_node *new_cast = pred;
98 if (totype == fromtype) return pred; /* Case for optimization! */
100 while (is_Pointer_type(totype) && is_Pointer_type(fromtype)) {
101 totype = get_pointer_points_to_type(totype);
102 fromtype = get_pointer_points_to_type(fromtype);
106 if (!is_Class_type(totype)) return pred;
107 if (!is_Class_type(fromtype)) return pred;
109 if ((get_class_supertype_index(totype, fromtype) != -1) ||
110 (get_class_supertype_index(fromtype, totype) != -1) ) {
111 /* It's just what we want ... */
115 set_cur_block(get_nodes_block(pred));
117 if (is_SubClass_of(totype, fromtype)) {
119 while (get_class_subtype_index(fromtype, totype) == -1) {
120 /* Insert a cast to a subtype of fromtype. */
121 ir_type *new_type = NULL;
123 int i, n_subtypes = get_class_n_subtypes(fromtype);
124 for (i = 0; i < n_subtypes && !new_type; ++i) {
125 ir_type *new_sub = get_class_subtype(fromtype, i);
126 if (is_SuperClass_of(new_sub, totype))
131 new_type = pointerize_type(new_type, ref_depth);
132 new_cast = new_Cast(pred, new_type);
134 n_casts_normalized ++;
135 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
136 if (get_trouts_state() != outs_none) add_type_cast(new_type, new_cast);
140 assert(is_SuperClass_of(totype, fromtype));
142 while (get_class_supertype_index(fromtype, totype) == -1) {
143 /* Insert a cast to a supertype of fromtype. */
144 ir_type *new_type = NULL;
145 int i, n_supertypes = get_class_n_supertypes(fromtype);
146 for (i = 0; i < n_supertypes && !new_type; ++i) {
147 ir_type *new_super = get_class_supertype(fromtype, i);
148 if (is_SubClass_of(new_super, totype))
149 new_type = new_super;
153 new_type = pointerize_type(new_type, ref_depth);
154 new_cast = new_Cast(pred, new_type);
156 n_casts_normalized ++;
157 set_irn_typeinfo_type(new_cast, new_type); /* keep type information up to date. */
158 if (get_trouts_state() != outs_none) add_type_cast(new_type, new_cast);
165 static void normalize_irn_class_cast(ir_node *n, void *env) {
168 if (get_irn_op(n) == op_Cast) {
169 ir_node *pred = get_Cast_op(n);
170 ir_type *totype = get_Cast_type(n);
171 res = normalize_values_type(totype, pred);
173 } else if (get_irn_op(n) == op_Call) {
174 int i, n_params = get_Call_n_params(n);
175 ir_type *tp = get_Call_type(n);
176 for (i = 0; i < n_params; ++i) {
177 res = normalize_values_type(get_method_param_type(tp, i), get_Call_param(n, i));
178 set_Call_param(n, i, res);
184 static void pure_normalize_irg_class_casts(ir_graph *irg) {
185 assert(get_irg_class_cast_state(irg) != ir_class_casts_any &&
186 "Cannot normalize irregular casts.");
187 if (get_irg_class_cast_state(irg) == ir_class_casts_normalized) {
188 verify_irg_class_cast_state(irg);
192 irg_walk_graph(irg, NULL, normalize_irn_class_cast, NULL);
193 set_irg_class_cast_state(irg, ir_class_casts_normalized);
197 void normalize_irg_class_casts(ir_graph *irg, gen_pointer_type_to_func gppt_fct) {
198 assert(get_irp_typeinfo_state() == ir_typeinfo_consistent);
200 if (gppt_fct) gen_pointer_type_to = gppt_fct;
202 if (!ptr_type_suffix)
203 ptr_type_suffix = new_id_from_str(PTR_TYPE_SUFFIX);
205 pure_normalize_irg_class_casts(irg);
207 gen_pointer_type_to = default_gen_pointer_type_to;
210 void normalize_irp_class_casts(gen_pointer_type_to_func gppt_fct) {
211 int i, n_irgs = get_irp_n_irgs();
212 if (gppt_fct) gen_pointer_type_to = gppt_fct;
214 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
215 simple_analyse_types();
217 for (i = 0; i < n_irgs; ++i) {
218 pure_normalize_irg_class_casts(get_irp_irg(i));
221 set_irp_class_cast_state(ir_class_casts_normalized);
222 gen_pointer_type_to = default_gen_pointer_type_to;
224 if (get_opt_optimize_class_casts_verbose() && get_firm_verbosity()) {
225 printf(" Cast normalization: %d Casts inserted.\n", n_casts_normalized);
231 /* - Cast optimization. ------------------------------------------- */
236 * (T1)(T2)x<T1> -> x<T1>
238 * (T3)(T2)x<T1> -> (T3)x<T1>
242 static void cancel_out_casts(ir_node *cast) {
243 ir_node *orig, *pred = get_Cast_op(cast);
244 ir_type *tp_cast, *tp_pred, *tp_orig;
247 if (get_irn_op(pred) != op_Cast) return;
248 orig = get_Cast_op(pred);
250 tp_cast = get_Cast_type(cast);
251 tp_pred = get_Cast_type(pred);
252 tp_orig = get_irn_typeinfo_type(orig);
254 while (is_Pointer_type(tp_cast) &&
255 is_Pointer_type(tp_pred) &&
256 is_Pointer_type(tp_orig) ) {
257 tp_cast = get_pointer_points_to_type(tp_cast);
258 tp_pred = get_pointer_points_to_type(tp_pred);
259 tp_orig = get_pointer_points_to_type(tp_orig);
263 if (!is_Class_type(tp_cast)) return;
264 if (!is_Class_type(tp_pred)) return;
265 if (!is_Class_type(tp_orig)) return;
267 if (is_SubClass_of(tp_pred, tp_cast) && get_opt_suppress_downcast_optimization())
270 if (tp_cast == tp_orig) {
271 exchange(cast, orig);
272 n_casts_removed += 2;
276 if (!(is_SubClass_of (tp_cast, tp_orig) || is_SubClass_of (tp_orig, tp_cast))) {
277 /* Avoid (B2)(A)(new B1()) --> (B2)(new B1())
278 * if B1 =!> B2 and B2 =!> B1
283 if ((is_SubClass_of (tp_cast, tp_pred) && is_SuperClass_of(tp_pred, tp_orig)) ||
284 (is_SuperClass_of(tp_cast, tp_pred) && is_SubClass_of (tp_pred, tp_orig)) ) {
285 /* Cast --> Pred --> Orig */
286 set_Cast_op (cast, orig);
291 static void concretize_selected_entity(ir_node *sel) {
292 ir_node *cast, *ptr = get_Sel_ptr(sel);
293 ir_type *orig_tp, *cast_tp;
294 ir_entity *new_ent, *sel_ent;
296 sel_ent = get_Sel_entity(sel);
297 cast = get_Sel_ptr(sel);
299 while (get_irn_op(cast) == op_Cast) {
300 cast_tp = get_Cast_type(cast);
301 ptr = get_Cast_op(cast);
302 orig_tp = get_irn_typeinfo_type(ptr);
304 if (!is_Pointer_type(orig_tp)) return;
305 if (!is_Pointer_type(cast_tp)) return;
306 orig_tp = get_pointer_points_to_type(orig_tp);
307 cast_tp = get_pointer_points_to_type(cast_tp);
308 if (!is_Class_type(orig_tp)) return;
309 if (!is_Class_type(cast_tp)) return;
311 /* We only want to concretize, but not generalize. */
312 if (!is_SuperClass_of(cast_tp, orig_tp)) return;
314 /* Hmm, we are not properly typed. */
315 if (get_class_member_index(cast_tp, sel_ent) == -1) return;
317 new_ent = resolve_ent_polymorphy(orig_tp, sel_ent);
319 /* New ent must be member of orig_tp. */
320 if (get_class_member_index(orig_tp, new_ent) == -1) return;
322 set_Sel_entity(sel, new_ent);
323 set_Sel_ptr(sel, ptr);
324 n_sels_concretized++;
331 static void concretize_Phi_type(ir_node *phi) {
332 int i, n_preds = get_Phi_n_preds(phi);
333 ir_node **pred = alloca(n_preds * sizeof(ir_node *));
335 ir_type *totype, *fromtype;
337 if (n_preds == 0) return;
338 pred[0] = get_Phi_pred(phi, 0);
340 if (get_irn_op(pred[0]) != op_Cast) return;
342 if (!is_Cast_upcast(pred[0])) return;
344 fromtype = get_irn_typeinfo_type(get_Cast_op(pred[0]));
345 totype = get_Cast_type(pred[0]);
347 pred[0] = get_Cast_op(pred[0]);
348 for (i = 1; i < n_preds; ++i) {
349 pred[i] = get_Phi_pred(phi, i);
350 if (get_irn_op(pred[i]) != op_Cast) return;
351 if (get_irn_typeinfo_type(get_Cast_op(pred[i])) != fromtype) return;
352 pred[i] = get_Cast_op(pred[i]);
356 set_cur_block(get_nodes_block(phi));
357 new = new_Phi(n_preds, pred, get_irn_mode(phi));
358 set_irn_typeinfo_type(new, fromtype);
359 new = new_Cast(new, totype);
360 set_irn_typeinfo_type(new, totype);
364 void remove_Cmp_Null_cast(ir_node *cmp) {
365 ir_node *cast, *null, *new_null;
366 int cast_pos, null_pos;
369 cast = get_Cmp_left(cmp);
371 if (get_irn_op(cast) != op_Cast) {
374 cast = get_Cmp_right(cmp);
376 if (get_irn_op(cast) != op_Cast) return;
378 null = get_Cmp_right(cmp);
382 if (get_irn_op(null) != op_Const) return;
383 if (!mode_is_reference(get_irn_mode(null))) return;
384 if (get_Const_tarval(null) != get_mode_null(get_irn_mode(null))) return;
387 set_irn_n(cmp, cast_pos, get_Cast_op(cast));
388 fromtype = get_irn_typeinfo_type(get_Cast_op(cast));
389 new_null = new_Const_type(get_Const_tarval(null), fromtype);
390 set_irn_typeinfo_type(new_null, fromtype);
391 set_irn_n(cmp, null_pos, new_null);
398 static void irn_optimize_class_cast(ir_node *n, void *env) {
400 if (get_irn_op(n) == op_Cast)
402 else if (get_irn_op(n) == op_Sel)
403 concretize_selected_entity(n);
404 else if (get_irn_op(n) == op_Phi)
405 concretize_Phi_type(n);
406 else if (get_irn_op(n) == op_Cmp)
407 remove_Cmp_Null_cast(n);
410 void optimize_class_casts(void) {
411 int i, n_irgs = get_irp_n_irgs();
413 if (get_irp_typeinfo_state() != ir_typeinfo_consistent)
414 simple_analyse_types();
416 all_irg_walk(NULL, irn_optimize_class_cast, NULL);
418 set_trouts_inconsistent();
419 for (i = 0; i < n_irgs; ++i)
420 set_irg_outs_inconsistent(get_irp_irg(i));
422 if (get_opt_optimize_class_casts_verbose() && get_firm_verbosity()) {
423 printf(" Cast optimization: %d Casts removed, %d Sels concretized.\n",
424 n_casts_removed, n_sels_concretized);