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
30 #include "iredges_t.h"
31 #include "raw_bitset.h"
44 #include "beintlive_t.h"
47 #include "lc_opts_enum.h"
49 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
51 typedef struct be_pre_spill_env_t {
53 const arch_register_class_t *cls;
56 static void prepare_constr_insn(be_pre_spill_env_t *env, ir_node *node)
58 const arch_register_class_t *cls = env->cls;
59 ir_node *block = get_nodes_block(node);
60 const ir_graph *irg = env->irg;
61 be_irg_t *birg = be_birg_from_irg(irg);
62 be_lv_t *lv = be_get_irg_liveness(irg);
64 unsigned *def_constr = NULL;
65 int arity = get_irn_arity(node);
70 /* Insert a copy for constraint inputs attached to a value which can't
71 * fulfill the constraint
72 * (typical example: stack pointer as input to copyb)
73 * TODO: This really just checks precolored registers at the moment and
74 * ignores the general case of not matching in/out constraints
76 for (i = 0; i < arity; ++i) {
77 ir_node *op = get_irn_n(node, i);
78 const arch_register_req_t *req = arch_get_irn_register_req_in(node, i);
79 const arch_register_t *reg;
84 reg = arch_get_irn_register(op);
88 /* precolored with an ignore register (which is not a joker like
90 if ((reg->type & arch_register_type_joker) ||
91 rbitset_is_set(birg->allocatable_regs, reg->global_index))
94 if (! (req->type & arch_register_req_type_limited))
96 if (rbitset_is_set(req->limited, reg->index))
99 copy = be_new_Copy(block, op);
100 stat_ev_int("constr_copy", 1);
101 sched_add_before(node, copy);
102 set_irn_n(node, i, copy);
103 DBG((dbg, LEVEL_3, "inserting ignore arg copy %+F for %+F pos %d\n",
107 /* insert copies for nodes that occur constrained more than once. */
108 for (i = 0; i < arity; ++i) {
111 const arch_register_req_t *req;
113 req = arch_get_irn_register_req_in(node, i);
117 if (! (req->type & arch_register_req_type_limited))
120 in = get_irn_n(node, i);
121 if (!arch_irn_consider_in_reg_alloc(cls, in))
124 for (i2 = i + 1; i2 < arity; ++i2) {
126 const arch_register_req_t *req2;
128 req2 = arch_get_irn_register_req_in(node, i2);
129 if (req2->cls != cls)
131 if (! (req2->type & arch_register_req_type_limited))
134 in2 = get_irn_n(node, i2);
138 /* if the constraint is the same, no copy is necessary
139 * TODO generalise unequal but overlapping constraints */
140 if (rbitsets_equal(req->limited, req2->limited, cls->n_regs))
143 copy = be_new_Copy(block, in);
144 stat_ev_int("constr_copy", 1);
146 sched_add_before(node, copy);
147 set_irn_n(node, i2, copy);
149 "inserting multiple constr copy %+F for %+F pos %d\n",
154 /* collect all registers occurring in out constraints. */
155 be_foreach_definition(node, cls, def,
156 if (! (req_->type & arch_register_req_type_limited))
158 if (def_constr == NULL) {
159 rbitset_alloca(def_constr, cls->n_regs);
161 rbitset_or(def_constr, req_->limited, cls->n_regs);
164 /* no output constraints => we're good */
165 if (def_constr == NULL) {
170 * insert copies for all constrained arguments living through the node
171 * and being constrained to a register which also occurs in out constraints.
173 rbitset_alloca(tmp, cls->n_regs);
174 for (i = 0; i < arity; ++i) {
175 const arch_register_req_t *req;
181 * 1) the operand is constrained.
182 * 2) lives through the node.
183 * 3) is constrained to a register occurring in out constraints.
185 req = arch_get_irn_register_req_in(node, i);
188 if (!(req->type & arch_register_req_type_limited))
191 in = get_irn_n(node, i);
192 if (!arch_irn_consider_in_reg_alloc(cls, in))
194 if (!be_values_interfere(lv, node, in))
197 rbitset_copy(tmp, req->limited, cls->n_regs);
198 rbitset_and(tmp, def_constr, cls->n_regs);
200 if (rbitset_is_empty(tmp, cls->n_regs))
204 * only create the copy if the operand is no copy.
205 * this is necessary since the assure constraints phase inserts
206 * Copies and Keeps for operands which must be different from the
207 * results. Additional copies here would destroy this.
212 copy = be_new_Copy(block, in);
213 sched_add_before(node, copy);
214 set_irn_n(node, i, copy);
215 DBG((dbg, LEVEL_3, "inserting constr copy %+F for %+F pos %d\n",
217 be_liveness_update(lv, in);
221 static void pre_spill_prepare_constr_walker(ir_node *block, void *data)
223 be_pre_spill_env_t *env = (be_pre_spill_env_t*)data;
224 sched_foreach(block, node) {
225 prepare_constr_insn(env, node);
229 void be_pre_spill_prepare_constr(ir_graph *irg,
230 const arch_register_class_t *cls)
232 be_pre_spill_env_t env;
233 memset(&env, 0, sizeof(env));
237 be_assure_live_sets(irg);
239 irg_block_walk_graph(irg, pre_spill_prepare_constr_walker, NULL, &env);
244 int be_coalesce_spill_slots = 1;
245 int be_do_remats = 1;
247 static const lc_opt_table_entry_t be_spill_options[] = {
248 LC_OPT_ENT_BOOL ("coalesce_slots", "coalesce the spill slots", &be_coalesce_spill_slots),
249 LC_OPT_ENT_BOOL ("remat", "try to rematerialize values instead of reloading", &be_do_remats),
253 static be_module_list_entry_t *spillers = NULL;
254 static const be_spiller_t *selected_spiller = NULL;
256 void be_register_spiller(const char *name, be_spiller_t *spiller)
258 if (selected_spiller == NULL)
259 selected_spiller = spiller;
260 be_add_module_to_list(&spillers, name, spiller);
263 void be_do_spill(ir_graph *irg, const arch_register_class_t *cls)
265 assert(selected_spiller != NULL);
267 selected_spiller->spill(irg, cls);
270 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spilloptions)
271 void be_init_spilloptions(void)
273 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
274 lc_opt_entry_t *spill_grp = lc_opt_get_grp(be_grp, "spill");
276 lc_opt_add_table(spill_grp, be_spill_options);
277 be_add_module_list_opt(be_grp, "spiller", "spill algorithm",
278 &spillers, (void**) &selected_spiller);
280 FIRM_DBG_REGISTER(dbg, "firm.be.spillprepare");