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 Common functions for chordal register allocation.
23 * @author Sebastian Hack
25 * @version $Id: bechordal.c 26750 2009-11-27 09:37:43Z bersch $
29 #include "bechordal_common.h"
36 #include "bechordal.h"
37 #include "bechordal_t.h"
41 #include "bestatevent.h"
48 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
50 /* Make a fourcc for border checking. */
51 #define BORDER_FOURCC FOURCC('B', 'O', 'R', 'D')
54 int has_reg_class(const be_chordal_env_t *env, const ir_node *irn)
56 return arch_irn_consider_in_reg_alloc(env->cls, irn);
59 static inline border_t *border_add(be_chordal_env_t *env, struct list_head *head,
60 ir_node *irn, unsigned step, unsigned pressure,
61 unsigned is_def, unsigned is_real)
68 b = OALLOC(env->obst, border_t);
70 /* also allocate the def and tie it to the use. */
71 def = OALLOCZ(env->obst, border_t);
76 * Set the link field of the irn to the def.
77 * This strongly relies on the fact, that the use is always
78 * made before the def.
80 set_irn_link(irn, def);
82 DEBUG_ONLY(b->magic = BORDER_FOURCC);
83 DEBUG_ONLY(def->magic = BORDER_FOURCC);
86 * If the def is encountered, the use was made and so was the
87 * the def node (see the code above). It was placed into the
88 * link field of the irn, so we can get it there.
90 b = get_irn_link(irn);
92 DEBUG_ONLY(assert(b && b->magic == BORDER_FOURCC && "Illegal border encountered"));
95 b->pressure = pressure;
100 list_add_tail(&b->list, head);
101 DBG((dbg, LEVEL_5, "\t\t%s adding %+F, step: %d\n", is_def ? "def" : "use", irn, step));
107 void create_borders(ir_node *block, void *env_ptr)
109 /* Convenience macro for a def */
110 #define border_def(irn, step, real) \
111 border_add(env, head, irn, step, pressure--, 1, real)
113 /* Convenience macro for a use */
114 #define border_use(irn, step, real) \
115 border_add(env, head, irn, step, ++pressure, 0, real)
117 be_chordal_env_t *env = env_ptr;
118 bitset_t *live = bitset_malloc(get_irg_last_idx(env->irg));
120 be_lv_t *lv = be_get_irg_liveness(env->irg);
125 unsigned pressure = 0;
126 struct list_head *head;
128 bitset_clear_all(live);
130 /* Set up the border list in the block info */
131 head = OALLOC(env->obst, struct list_head);
132 INIT_LIST_HEAD(head);
133 assert(pmap_get(env->border_heads, block) == NULL);
134 pmap_insert(env->border_heads, block, head);
137 * Make final uses of all values live out of the block.
138 * They are necessary to build up real intervals.
140 be_lv_foreach(lv, block, be_lv_state_end, i) {
141 ir_node *irn = be_lv_get_irn(lv, block, i);
142 if (has_reg_class(env, irn)) {
143 DBG((dbg, LEVEL_3, "\tMaking live: %+F/%d\n", irn, get_irn_idx(irn)));
144 bitset_set(live, get_irn_idx(irn));
145 border_use(irn, step, 0);
151 * Determine the last uses of a value inside the block, since they are
152 * relevant for the interval borders.
154 sched_foreach_reverse(block, irn) {
155 DBG((dbg, LEVEL_1, "\tinsn: %+F, pressure: %d\n", irn, pressure));
156 DBG((dbg, LEVEL_2, "\tlive: %B\n", live));
158 if (get_irn_mode(irn) == mode_T) {
159 const ir_edge_t *edge;
161 foreach_out_edge(irn, edge) {
162 ir_node *proj = get_edge_src_irn(edge);
165 * If the node defines some value, which can put into a
166 * register of the current class, make a border for it.
168 if (has_reg_class(env, proj)) {
169 int nr = get_irn_idx(proj);
171 bitset_clear(live, nr);
172 border_def(proj, step, 1);
177 * If the node defines some value, which can put into a
178 * register of the current class, make a border for it.
180 if (has_reg_class(env, irn)) {
181 int nr = get_irn_idx(irn);
183 bitset_clear(live, nr);
184 border_def(irn, step, 1);
189 * If the node is no phi node we can examine the uses.
192 for (i = 0, n = get_irn_arity(irn); i < n; ++i) {
193 ir_node *op = get_irn_n(irn, i);
195 if (has_reg_class(env, op)) {
196 int nr = get_irn_idx(op);
197 const char *msg = "-";
199 if (!bitset_is_set(live, nr)) {
200 border_use(op, step, 1);
201 bitset_set(live, nr);
205 DBG((dbg, LEVEL_4, "\t\t%s pos: %d, use: %+F\n", msg, i, op));
212 bitset_foreach(live, elm) {
213 ir_node *irn = get_idx_irn(env->irg, elm);
214 if (be_is_live_in(lv, block, irn))
215 border_def(irn, step, 0);
222 be_insn_t *chordal_scan_insn(be_chordal_env_t *env, ir_node *irn)
226 ie.ignore_colors = env->ignore_colors;
229 return be_scan_insn(&ie, irn);
232 ir_node *pre_process_constraints(be_chordal_env_t *env, be_insn_t **the_insn)
234 be_insn_t *insn = *the_insn;
235 ir_node *perm = NULL;
236 bitset_t *out_constr = bitset_alloca(env->cls->n_regs);
237 const ir_edge_t *edge;
240 assert(insn->has_constraints && "only do this for constrained nodes");
243 * Collect all registers that occur in output constraints.
244 * This is necessary, since if the insn has one of these as an input constraint
245 * and the corresponding operand interferes with the insn, the operand must
248 for (i = 0; i < insn->use_start; ++i) {
249 be_operand_t *op = &insn->ops[i];
250 if (op->has_constraints)
251 bitset_or(out_constr, op->regs);
255 * Make the Perm, recompute liveness and re-scan the insn since the
256 * in operands are now the Projs of the Perm.
258 perm = insert_Perm_after(env->irg, env->cls, sched_prev(insn->irn));
260 /* Registers are propagated by insert_Perm_after(). Clean them here! */
264 be_stat_ev("constr_perm", get_irn_arity(perm));
265 foreach_out_edge(perm, edge) {
266 ir_node *proj = get_edge_src_irn(edge);
267 arch_set_irn_register(proj, NULL);
271 * We also have to re-build the insn since the input operands are now the Projs of
272 * the Perm. Recomputing liveness is also a good idea if a Perm is inserted, since
273 * the live sets may change.
275 obstack_free(env->obst, insn);
276 *the_insn = insn = chordal_scan_insn(env, insn->irn);
279 * Copy the input constraints of the insn to the Perm as output
280 * constraints. Succeeding phases (coalescing) will need that.
282 for (i = insn->use_start; i < insn->n_ops; ++i) {
283 be_operand_t *op = &insn->ops[i];
284 ir_node *proj = op->carrier;
286 * Note that the predecessor must not be a Proj of the Perm,
287 * since ignore-nodes are not Perm'ed.
289 if (op->has_constraints && is_Proj(proj) && get_Proj_pred(proj) == perm) {
290 be_set_constr_out(perm, get_Proj_proj(proj), op->req);
297 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_chordal_common);
298 void be_init_chordal_common(void)
300 FIRM_DBG_REGISTER(dbg, "firm.be.chordal_common");