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 Spill module selection; Preparation steps
23 * @author Matthias Braun
31 #include "iredges_t.h"
32 #include "raw_bitset.h"
45 #include "beintlive_t.h"
48 #include "lc_opts_enum.h"
50 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
52 typedef struct be_pre_spill_env_t {
54 const arch_register_class_t *cls;
57 static void prepare_constr_insn(be_pre_spill_env_t *env, ir_node *node)
59 const arch_register_class_t *cls = env->cls;
60 ir_node *block = get_nodes_block(node);
61 const ir_graph *irg = env->irg;
62 be_irg_t *birg = be_birg_from_irg(irg);
63 be_lv_t *lv = be_get_irg_liveness(irg);
65 unsigned *def_constr = NULL;
66 int arity = get_irn_arity(node);
71 /* Insert a copy for constraint inputs attached to a value which can't
72 * fulfill the constraint
73 * (typical example: stack pointer as input to copyb)
74 * TODO: This really just checks precolored registers at the moment and
75 * ignores the general case of not matching in/out constraints
77 for (i = 0; i < arity; ++i) {
78 ir_node *op = get_irn_n(node, i);
79 const arch_register_req_t *req = arch_get_irn_register_req_in(node, i);
80 const arch_register_t *reg;
85 reg = arch_get_irn_register(op);
89 /* precolored with an ignore register (which is not a joker like
91 if ((reg->type & arch_register_type_joker) ||
92 rbitset_is_set(birg->allocatable_regs, reg->global_index))
95 if (! (req->type & arch_register_req_type_limited))
97 if (rbitset_is_set(req->limited, reg->index))
100 copy = be_new_Copy(block, op);
101 stat_ev_int("constr_copy", 1);
102 sched_add_before(node, copy);
103 set_irn_n(node, i, copy);
104 DBG((dbg, LEVEL_3, "inserting ignore arg copy %+F for %+F pos %d\n",
108 /* insert copies for nodes that occur constrained more than once. */
109 for (i = 0; i < arity; ++i) {
112 const arch_register_req_t *req;
114 req = arch_get_irn_register_req_in(node, i);
118 if (! (req->type & arch_register_req_type_limited))
121 in = get_irn_n(node, i);
122 if (!arch_irn_consider_in_reg_alloc(cls, in))
125 for (i2 = i + 1; i2 < arity; ++i2) {
127 const arch_register_req_t *req2;
129 req2 = arch_get_irn_register_req_in(node, i2);
130 if (req2->cls != cls)
132 if (! (req2->type & arch_register_req_type_limited))
135 in2 = get_irn_n(node, i2);
139 /* if the constraint is the same, no copy is necessary
140 * TODO generalise unequal but overlapping constraints */
141 if (rbitsets_equal(req->limited, req2->limited, cls->n_regs))
144 copy = be_new_Copy(block, in);
145 stat_ev_int("constr_copy", 1);
147 sched_add_before(node, copy);
148 set_irn_n(node, i2, copy);
150 "inserting multiple constr copy %+F for %+F pos %d\n",
155 /* collect all registers occurring in out constraints. */
156 be_foreach_definition(node, cls, def,
157 if (! (req_->type & arch_register_req_type_limited))
159 if (def_constr == NULL) {
160 rbitset_alloca(def_constr, cls->n_regs);
162 rbitset_or(def_constr, req_->limited, cls->n_regs);
165 /* no output constraints => we're good */
166 if (def_constr == NULL) {
171 * insert copies for all constrained arguments living through the node
172 * and being constrained to a register which also occurs in out constraints.
174 rbitset_alloca(tmp, cls->n_regs);
175 for (i = 0; i < arity; ++i) {
176 const arch_register_req_t *req;
182 * 1) the operand is constrained.
183 * 2) lives through the node.
184 * 3) is constrained to a register occurring in out constraints.
186 req = arch_get_irn_register_req_in(node, i);
189 if (!(req->type & arch_register_req_type_limited))
192 in = get_irn_n(node, i);
193 if (!arch_irn_consider_in_reg_alloc(cls, in))
195 if (!be_values_interfere(lv, node, in))
198 rbitset_copy(tmp, req->limited, cls->n_regs);
199 rbitset_and(tmp, def_constr, cls->n_regs);
201 if (rbitset_is_empty(tmp, cls->n_regs))
205 * only create the copy if the operand is no copy.
206 * this is necessary since the assure constraints phase inserts
207 * Copies and Keeps for operands which must be different from the
208 * results. Additional copies here would destroy this.
213 copy = be_new_Copy(block, in);
214 sched_add_before(node, copy);
215 set_irn_n(node, i, copy);
216 DBG((dbg, LEVEL_3, "inserting constr copy %+F for %+F pos %d\n",
218 be_liveness_update(lv, in);
222 static void pre_spill_prepare_constr_walker(ir_node *block, void *data)
224 be_pre_spill_env_t *env = (be_pre_spill_env_t*)data;
226 sched_foreach(block, node) {
227 prepare_constr_insn(env, node);
231 void be_pre_spill_prepare_constr(ir_graph *irg,
232 const arch_register_class_t *cls)
234 be_pre_spill_env_t env;
235 memset(&env, 0, sizeof(env));
239 be_assure_liveness(irg);
241 irg_block_walk_graph(irg, pre_spill_prepare_constr_walker, NULL, &env);
246 int be_coalesce_spill_slots = 1;
247 int be_do_remats = 1;
249 static const lc_opt_table_entry_t be_spill_options[] = {
250 LC_OPT_ENT_BOOL ("coalesce_slots", "coalesce the spill slots", &be_coalesce_spill_slots),
251 LC_OPT_ENT_BOOL ("remat", "try to rematerialize values instead of reloading", &be_do_remats),
255 static be_module_list_entry_t *spillers = NULL;
256 static const be_spiller_t *selected_spiller = NULL;
258 void be_register_spiller(const char *name, be_spiller_t *spiller)
260 if (selected_spiller == NULL)
261 selected_spiller = spiller;
262 be_add_module_to_list(&spillers, name, spiller);
265 void be_do_spill(ir_graph *irg, const arch_register_class_t *cls)
267 assert(selected_spiller != NULL);
269 selected_spiller->spill(irg, cls);
272 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spilloptions)
273 void be_init_spilloptions(void)
275 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
276 lc_opt_entry_t *spill_grp = lc_opt_get_grp(be_grp, "spill");
278 lc_opt_add_table(spill_grp, be_spill_options);
279 be_add_module_list_opt(be_grp, "spiller", "spill algorithm",
280 &spillers, (void**) &selected_spiller);
282 FIRM_DBG_REGISTER(dbg, "firm.be.spillprepare");