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 Performs SSA-Destruction.
23 * @author Daniel Grund
29 #include "bessadestr.h"
36 #include "iredges_t.h"
44 #include "bechordal_t.h"
49 #include "bestatevent.h"
51 #include "beintlive_t.h"
53 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
55 #define get_reg(irn) arch_get_irn_register(irn)
56 #define set_reg(irn, reg) arch_set_irn_register(irn, reg)
58 static void clear_link(ir_node *irn, void *data)
61 set_irn_link(irn, NULL);
65 * For each block build a linked list of phis that
67 * - have the current register class
68 * The list is rooted at get_irn_link(BB).
70 static void collect_phis_walker(ir_node *irn, void *data)
72 be_chordal_env_t *env = data;
73 if (is_Phi(irn) && chordal_has_class(env, irn)) {
74 ir_node *bl = get_nodes_block(irn);
75 set_irn_link(irn, get_irn_link(bl));
76 set_irn_link(bl, irn);
81 * This struct represents a Proj for a Perm.
82 * It records the argument in the Perm and the corresponding Proj of the
86 ir_node *arg; /**< The phi argument to make the Proj for. */
87 int pos; /**< The proj number the Proj will get.
88 This also denotes the position of @p arg
89 in the in array of the Perm. */
90 ir_node *proj; /**< The proj created for @p arg. */
93 static int cmp_perm_proj(const void *a, const void *b, size_t n)
95 const perm_proj_t *p = a;
96 const perm_proj_t *q = b;
99 return !(p->arg == q->arg);
102 typedef struct insert_all_perms_env_t {
103 be_chordal_env_t *chordal_env;
105 } insert_all_perms_env_t;
108 * Insert Perms in all predecessors of a block containing a phi
110 static void insert_all_perms_walker(ir_node *bl, void *data)
112 insert_all_perms_env_t *env = data;
113 be_chordal_env_t *chordal_env = env->chordal_env;
114 pmap *perm_map = env->perm_map;
115 be_lv_t *lv = chordal_env->birg->lv;
118 assert(is_Block(bl));
120 /* If the link flag is NULL, this block has no phis. */
121 if (!get_irn_link(bl))
124 /* Look at all predecessors of the phi block */
125 for (i = 0, n = get_irn_arity(bl); i < n; ++i) {
126 ir_node *phi, *perm, *insert_after, **in;
128 set *arg_set = new_set(cmp_perm_proj, chordal_env->cls->n_regs);
129 ir_node *pred_bl = get_Block_cfgpred_block(bl, i);
132 assert(!pmap_contains(perm_map, pred_bl) && "Already permed that block");
135 * Note that all phis in the list are in the same
136 * register class by construction.
138 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
139 ir_node *arg = get_irn_n(phi, i);
140 const arch_register_req_t *req = arch_get_register_req_out(arg);
144 if (req->type & arch_register_req_type_ignore)
147 hash = hash_irn(arg);
149 pp = set_find(arg_set, &templ, sizeof(templ), hash);
152 * If a proj_perm_t entry has not been made in the argument set,
153 * create one. The only restriction is, that the phi argument
154 * may not be live in at the current block, since this argument
155 * interferes with the phi and must thus not be member of a
156 * Perm. A copy will be inserted for this argument later on.
158 if (!pp && !be_is_live_in(lv, bl, arg)) {
159 templ.pos = n_projs++;
160 set_insert(arg_set, &templ, sizeof(templ), hash);
167 * Create a new Perm with the arguments just collected
168 * above in the arg_set and insert it into the schedule.
170 in = XMALLOCN(ir_node*, n_projs);
171 for (pp = set_first(arg_set); pp; pp = set_next(arg_set))
172 in[pp->pos] = pp->arg;
174 perm = be_new_Perm(chordal_env->cls, pred_bl, n_projs, in);
175 be_stat_ev("phi_perm", n_projs);
177 insert_after = sched_skip(sched_last(pred_bl), 0, sched_skip_cf_predicator, NULL);
178 sched_add_after(insert_after, perm);
181 * Make the Projs for the Perm and insert into schedule.
182 * Register allocation is copied from the former phi
183 * arguments to the projs (new phi arguments).
186 for (pp = set_first(arg_set); pp; pp = set_next(arg_set)) {
187 ir_node *proj = new_r_Proj(perm, get_irn_mode(pp->arg), pp->pos);
189 assert(get_reg(pp->arg));
190 set_reg(proj, get_reg(pp->arg));
192 DBG((dbg, LEVEL_2, "Copy register assignment %s from %+F to %+F\n", get_reg(pp->arg)->name, pp->arg, pp->proj));
196 * Set the phi nodes to their new arguments: The Projs of the Perm
198 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
201 templ.arg = get_irn_n(phi, i);
202 pp = set_find(arg_set, &templ, sizeof(templ), hash_irn(templ.arg));
204 /* If not found, it was an interfering argument */
206 set_irn_n(phi, i, pp->proj);
207 be_liveness_introduce(lv, pp->proj);
211 /* update the liveness of the Perm's operands. It might be changed. */
214 for (i = 0; i < n_projs; ++i)
215 be_liveness_update(lv, in[i]);
219 /* register in perm map */
220 pmap_insert(perm_map, pred_bl, perm);
227 #define is_pinned(irn) (get_irn_link(irn))
228 #define get_pinning_block(irn) ((ir_node *)get_irn_link(irn))
229 #define pin_irn(irn, lock) (set_irn_link(irn, lock))
232 * Adjusts the register allocation for the (new) phi-operands
233 * and insert duplicates iff necessary.
235 static void set_regs_or_place_dupls_walker(ir_node *bl, void *data)
237 be_chordal_env_t *chordal_env = data;
238 be_lv_t *lv = chordal_env->birg->lv;
241 /* Consider all phis of this block */
242 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
243 ir_node *phi_block = get_nodes_block(phi);
244 const arch_register_t *phi_reg = get_reg(phi);
245 const arch_register_class_t *cls = phi_reg->reg_class;
249 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
251 /* process all arguments of the phi */
252 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
253 ir_node *arg = get_irn_n(phi, i);
254 const arch_register_req_t *req = arch_get_register_req_out(arg);
255 const arch_register_t *arg_reg;
258 if (req->type & arch_register_req_type_ignore)
261 arg_block = get_Block_cfgpred_block(phi_block, i);
262 arg_reg = get_reg(arg);
264 assert(arg_reg && "Register must be set while placing perms");
266 DBG((dbg, LEVEL_1, " for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
268 if (be_values_interfere(lv, phi, arg)) {
270 Insert a duplicate in arguments block,
271 make it the new phi arg,
273 insert it into schedule,
276 ir_node *dupl = be_new_Copy(cls, arg_block, arg);
278 /* this is commented out because it will fail in case of unknown float */
280 ir_mode *m_phi = get_irn_mode(phi), *m_dupl = get_irn_mode(dupl);
283 Conv signed <-> unsigned is killed on ia32
284 check for: (both int OR both float) AND equal mode sizes
286 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
287 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
288 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
291 set_irn_n(phi, i, dupl);
292 set_reg(dupl, phi_reg);
293 sched_add_after(sched_skip(sched_last(arg_block), 0, sched_skip_cf_predicator, NULL), dupl);
294 pin_irn(dupl, phi_block);
295 be_liveness_introduce(lv, dupl);
296 be_liveness_update(lv, arg);
297 DBG((dbg, LEVEL_1, " they do interfere: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
298 continue; /* with next argument */
301 if (phi_reg == arg_reg) {
302 /* Phi and arg have the same register, so pin and continue */
303 pin_irn(arg, phi_block);
304 DBG((dbg, LEVEL_1, " arg has same reg: pin %+F(%s)\n", arg, get_reg(arg)->name));
308 DBG((dbg, LEVEL_1, " they do not interfere\n"));
309 assert(is_Proj(arg));
311 First check if there is an other phi
313 - having arg at the current pos in its arg-list
314 - having the same color as arg
316 If found, then pin the arg (for that phi)
318 if (! is_pinned(arg)) {
321 DBG((dbg, LEVEL_1, " searching for phi with same arg having args register\n"));
323 for (other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
325 assert(is_Phi(other_phi) &&
326 get_nodes_block(phi) == get_nodes_block(other_phi) &&
327 "link fields are screwed up");
329 if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
330 DBG((dbg, LEVEL_1, " found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
331 pin_irn(arg, phi_block);
337 if (is_pinned(arg)) {
339 Insert a duplicate of the original value in arguments block,
340 make it the new phi arg,
342 insert it into schedule,
345 ir_node *perm = get_Proj_pred(arg);
346 ir_node *dupl = be_new_Copy(cls, arg_block, arg);
349 /* this is commented out because it will fail in case of unknown float */
351 ir_mode *m_phi = get_irn_mode(phi);
352 ir_mode *m_dupl = get_irn_mode(dupl);
355 Conv signed <-> unsigned is killed on ia32
356 check for: (both int OR both float) AND equal mode sizes
358 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
359 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
360 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
363 set_irn_n(phi, i, dupl);
364 set_reg(dupl, phi_reg);
365 /* skip the Perm's Projs and insert the copies behind. */
366 for (ins = sched_next(perm); is_Proj(ins); ins = sched_next(ins));
367 sched_add_before(ins, dupl);
368 pin_irn(dupl, phi_block);
369 be_liveness_introduce(lv, dupl);
370 be_liveness_update(lv, arg);
371 DBG((dbg, LEVEL_1, " arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
374 No other phi has the same color (else arg would have been pinned),
375 so just set the register and pin
377 set_reg(arg, phi_reg);
378 pin_irn(arg, phi_block);
379 DBG((dbg, LEVEL_1, " arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
385 void be_ssa_destruction(be_chordal_env_t *chordal_env)
387 insert_all_perms_env_t insert_perms_env;
388 pmap *perm_map = pmap_create();
389 ir_graph *irg = chordal_env->irg;
390 be_lv_t *lv = be_assure_liveness(chordal_env->birg);
392 FIRM_DBG_REGISTER(dbg, "ir.be.ssadestr");
394 be_liveness_invalidate(lv);
396 /* create a map for fast lookup of perms: block --> perm */
397 irg_walk_graph(irg, clear_link, collect_phis_walker, chordal_env);
399 DBG((dbg, LEVEL_1, "Placing perms...\n"));
400 insert_perms_env.chordal_env = chordal_env;
401 insert_perms_env.perm_map = perm_map;
402 irg_block_walk_graph(irg, insert_all_perms_walker, NULL, &insert_perms_env);
404 // Matze: really needed here?
405 // Sebastian: Yes. the walker function uses interference.
406 be_liveness_invalidate(lv);
408 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
409 be_dump(irg, "-ssa_destr_perms_placed", dump_ir_block_graph_sched);
411 be_liveness_assure_chk(lv);
413 DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
414 irg_block_walk_graph(irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
416 /* TODO: unfortunately updating doesn't work yet. */
417 be_liveness_invalidate(lv);
419 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
420 be_dump(irg, "-ssa_destr_regs_set", dump_ir_block_graph_sched);
422 pmap_destroy(perm_map);
425 static void ssa_destruction_check_walker(ir_node *bl, void *data)
431 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
432 const arch_register_t *phi_reg, *arg_reg;
434 phi_reg = get_reg(phi);
435 /* iterate over all args of phi */
436 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
437 ir_node *arg = get_irn_n(phi, i);
438 const arch_register_req_t *req = arch_get_register_req_out(arg);
440 if (req->type & arch_register_req_type_ignore)
443 arg_reg = get_reg(arg);
445 if (phi_reg != arg_reg) {
446 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
450 if (! is_pinned(arg)) {
451 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
458 void be_ssa_destruction_check(be_chordal_env_t *chordal_env)
460 irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, NULL);