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
28 #include "bechordal_common.h"
35 #include "bechordal.h"
36 #include "bechordal_t.h"
40 #include "bestatevent.h"
47 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
49 /* Make a fourcc for border checking. */
50 #define BORDER_FOURCC FOURCC('B', 'O', 'R', 'D')
52 int has_reg_class(const be_chordal_env_t *env, const ir_node *irn)
54 return arch_irn_consider_in_reg_alloc(env->cls, irn);
57 static inline border_t *border_add(be_chordal_env_t *env, struct list_head *head,
58 ir_node *irn, unsigned step, unsigned pressure,
59 unsigned is_def, unsigned is_real)
66 b = OALLOC(env->obst, border_t);
68 /* also allocate the def and tie it to the use. */
69 def = OALLOCZ(env->obst, border_t);
74 * Set the link field of the irn to the def.
75 * This strongly relies on the fact, that the use is always
76 * made before the def.
78 set_irn_link(irn, def);
80 DEBUG_ONLY(b->magic = BORDER_FOURCC;)
81 DEBUG_ONLY(def->magic = BORDER_FOURCC;)
84 * If the def is encountered, the use was made and so was the
85 * the def node (see the code above). It was placed into the
86 * link field of the irn, so we can get it there.
88 b = (border_t*)get_irn_link(irn);
90 DEBUG_ONLY(assert(b && b->magic == BORDER_FOURCC && "Illegal border encountered");)
93 b->pressure = pressure;
98 list_add_tail(&b->list, head);
99 DBG((dbg, LEVEL_5, "\t\t%s adding %+F, step: %d\n", is_def ? "def" : "use", irn, step));
105 void create_borders(ir_node *block, void *env_ptr)
107 /* Convenience macro for a def */
108 #define border_def(irn, step, real) \
109 border_add(env, head, irn, step, pressure--, 1, real)
111 /* Convenience macro for a use */
112 #define border_use(irn, step, real) \
113 border_add(env, head, irn, step, ++pressure, 0, real)
115 be_chordal_env_t *env = (be_chordal_env_t*)env_ptr;
116 bitset_t *live = bitset_malloc(get_irg_last_idx(env->irg));
118 be_lv_t *lv = be_get_irg_liveness(env->irg);
123 unsigned pressure = 0;
124 struct list_head *head;
126 bitset_clear_all(live);
128 /* Set up the border list in the block info */
129 head = OALLOC(env->obst, struct list_head);
130 INIT_LIST_HEAD(head);
131 assert(pmap_get(env->border_heads, block) == NULL);
132 pmap_insert(env->border_heads, block, head);
135 * Make final uses of all values live out of the block.
136 * They are necessary to build up real intervals.
138 be_lv_foreach(lv, block, be_lv_state_end, i) {
139 ir_node *irn = be_lv_get_irn(lv, block, i);
140 if (has_reg_class(env, irn)) {
141 DBG((dbg, LEVEL_3, "\tMaking live: %+F/%d\n", irn, get_irn_idx(irn)));
142 bitset_set(live, get_irn_idx(irn));
143 border_use(irn, step, 0);
149 * Determine the last uses of a value inside the block, since they are
150 * relevant for the interval borders.
152 sched_foreach_reverse(block, irn) {
153 DBG((dbg, LEVEL_1, "\tinsn: %+F, pressure: %d\n", irn, pressure));
154 DBG((dbg, LEVEL_2, "\tlive: %B\n", live));
156 if (get_irn_mode(irn) == mode_T) {
157 const ir_edge_t *edge;
159 foreach_out_edge(irn, edge) {
160 ir_node *proj = get_edge_src_irn(edge);
163 * If the node defines some value, which can put into a
164 * register of the current class, make a border for it.
166 if (has_reg_class(env, proj)) {
167 int nr = get_irn_idx(proj);
169 bitset_clear(live, nr);
170 border_def(proj, step, 1);
175 * If the node defines some value, which can put into a
176 * register of the current class, make a border for it.
178 if (has_reg_class(env, irn)) {
179 int nr = get_irn_idx(irn);
181 bitset_clear(live, nr);
182 border_def(irn, step, 1);
187 * If the node is no phi node we can examine the uses.
190 for (i = 0, n = get_irn_arity(irn); i < n; ++i) {
191 ir_node *op = get_irn_n(irn, i);
193 if (has_reg_class(env, op)) {
194 int nr = get_irn_idx(op);
195 const char *msg = "-";
197 if (!bitset_is_set(live, nr)) {
198 border_use(op, step, 1);
199 bitset_set(live, nr);
203 DBG((dbg, LEVEL_4, "\t\t%s pos: %d, use: %+F\n", msg, i, op));
210 bitset_foreach(live, elm) {
211 ir_node *irn = get_idx_irn(env->irg, elm);
212 if (be_is_live_in(lv, block, irn))
213 border_def(irn, step, 0);
220 be_insn_t *chordal_scan_insn(be_chordal_env_t *env, ir_node *irn)
224 ie.allocatable_regs = env->allocatable_regs;
227 return be_scan_insn(&ie, irn);
230 ir_node *pre_process_constraints(be_chordal_env_t *env, be_insn_t **the_insn)
232 be_insn_t *insn = *the_insn;
233 ir_node *perm = NULL;
234 bitset_t *out_constr = bitset_alloca(env->cls->n_regs);
235 const ir_edge_t *edge;
238 assert(insn->has_constraints && "only do this for constrained nodes");
241 * Collect all registers that occur in output constraints.
242 * This is necessary, since if the insn has one of these as an input constraint
243 * and the corresponding operand interferes with the insn, the operand must
246 for (i = 0; i < insn->use_start; ++i) {
247 be_operand_t *op = &insn->ops[i];
248 if (op->has_constraints)
249 bitset_or(out_constr, op->regs);
253 * Make the Perm, recompute liveness and re-scan the insn since the
254 * in operands are now the Projs of the Perm.
256 perm = insert_Perm_after(env->irg, env->cls, sched_prev(insn->irn));
258 /* Registers are propagated by insert_Perm_after(). Clean them here! */
262 be_stat_ev("constr_perm", get_irn_arity(perm));
263 foreach_out_edge(perm, edge) {
264 ir_node *proj = get_edge_src_irn(edge);
265 arch_set_irn_register(proj, NULL);
269 * We also have to re-build the insn since the input operands are now the Projs of
270 * the Perm. Recomputing liveness is also a good idea if a Perm is inserted, since
271 * the live sets may change.
273 obstack_free(env->obst, insn);
274 *the_insn = insn = chordal_scan_insn(env, insn->irn);
277 * Copy the input constraints of the insn to the Perm as output
278 * constraints. Succeeding phases (coalescing) will need that.
280 for (i = insn->use_start; i < insn->n_ops; ++i) {
281 be_operand_t *op = &insn->ops[i];
282 ir_node *proj = op->carrier;
284 * Note that the predecessor must not be a Proj of the Perm,
285 * since ignore-nodes are not Perm'ed.
287 if (op->has_constraints && is_Proj(proj) && get_Proj_pred(proj) == perm) {
288 be_set_constr_out(perm, get_Proj_proj(proj), op->req);
295 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_chordal_common)
296 void be_init_chordal_common(void)
298 FIRM_DBG_REGISTER(dbg, "firm.be.chordal_common");