4 * Copyright: (c) Universitaet Karlsruhe
5 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
7 * Performs SSA-Destruction.
18 #include "iredges_t.h"
26 #include "bechordal_t.h"
30 #include "besched_t.h"
31 #include "benodesets.h"
32 #include "bestatevent.h"
34 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
36 #define get_chordal_arch(ce) ((ce)->birg->main_env->arch_env)
37 #define get_reg(irn) arch_get_irn_register(get_chordal_arch(chordal_env), irn)
38 #define set_reg(irn, reg) arch_set_irn_register(get_chordal_arch(chordal_env), irn, reg)
40 #define is_Perm(irn) (arch_irn_class_is(arch_env, irn, perm))
41 #define get_reg_cls(irn) (arch_get_irn_reg_class(arch_env, irn, -1))
42 #define is_curr_reg_class(irn) (get_reg_cls(p) == chordal_env->cls)
44 static void clear_link(ir_node *irn, void *data) {
45 set_irn_link(irn, NULL);
49 * For each block build a linked list of phis that
51 * - have the current register class
52 * The list is rooted at get_irn_link(BB).
54 static void collect_phis_walker(ir_node *irn, void *data) {
55 be_chordal_env_t *env = data;
56 if(is_Phi(irn) && chordal_has_class(env, irn)) {
57 ir_node *bl = get_nodes_block(irn);
58 set_irn_link(irn, get_irn_link(bl));
59 set_irn_link(bl, irn);
64 * This struct represents a Proj for a Perm.
65 * It records the argument in the Perm and the corresponding Proj of the
69 ir_node *arg; /**< The phi argument to make the Proj for. */
70 int pos; /**< The proj number the Proj will get.
71 This also denotes the position of @p arg
72 in the in array of the Perm. */
73 ir_node *proj; /**< The proj created for @p arg. */
76 static int cmp_perm_proj(const void *a, const void *b, size_t n) {
77 const perm_proj_t *p = a;
78 const perm_proj_t *q = b;
79 return !(p->arg == q->arg);
83 * Insert Perms in all predecessors of a block containing a phi
85 static void insert_all_perms_walker(ir_node *bl, void *data) {
86 be_chordal_env_t *chordal_env = data;
87 pmap *perm_map = chordal_env->data;
88 ir_graph *irg = chordal_env->irg;
93 /* If the link flag is NULL, this block has no phis. */
97 /* Look at all predecessors of the phi block */
98 for(i = 0, n = get_irn_arity(bl); i < n; ++i) {
99 ir_node *phi, *perm, *insert_after, **in;
101 set *arg_set = new_set(cmp_perm_proj, chordal_env->cls->n_regs);
102 ir_node *pred_bl = get_Block_cfgpred_block(bl, i);
105 assert(!pmap_contains(perm_map, pred_bl) && "Already permed that block");
108 * Note that all phis in the list are in the same
109 * register class by construction.
111 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
113 ir_node *arg = get_irn_n(phi, i);
114 unsigned hash = nodeset_hash(arg);
117 pp = set_find(arg_set, &templ, sizeof(templ), hash);
120 * If a proj_perm_t entry has not been made in the argument set,
121 * create one. The only restriction is, that the phi argument
122 * may not be live in at the current block, since this argument
123 * interferes with the phi and must thus not be member of a
124 * Perm. A copy will be inserted for this argument alter on.
126 if(!pp && !be_is_live_in(chordal_env->lv, bl, arg)) {
127 templ.pos = n_projs++;
128 set_insert(arg_set, &templ, sizeof(templ), hash);
135 * Create a new Perm with the arguments just collected
136 * above in the arg_set and insert it into the schedule.
138 in = xmalloc(n_projs * sizeof(in[0]));
139 for(pp = set_first(arg_set); pp; pp = set_next(arg_set))
140 in[pp->pos] = pp->arg;
142 perm = be_new_Perm(chordal_env->cls, irg, pred_bl, n_projs, in);
143 be_stat_ev("phi_perm", n_projs);
146 insert_after = sched_skip(sched_last(pred_bl), 0, sched_skip_cf_predicator, chordal_env->birg->main_env->arch_env);
147 sched_add_after(insert_after, perm);
150 * Make the Projs for the Perm and insert into schedule.
151 * Register allocation is copied from the former phi
152 * arguments to the projs (new phi arguments).
155 for(pp = set_first(arg_set); pp; pp = set_next(arg_set)) {
156 ir_node *proj = new_r_Proj(irg, pred_bl, perm, get_irn_mode(pp->arg), pp->pos);
158 assert(get_reg(pp->arg));
159 set_reg(proj, get_reg(pp->arg));
160 sched_add_after(insert_after, proj);
162 DBG((dbg, LEVEL_2, "Copy register assignment %s from %+F to %+F\n", get_reg(pp->arg)->name, pp->arg, pp->proj));
166 * Set the phi nodes to their new arguments: The Projs of the Perm
168 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
171 templ.arg = get_irn_n(phi, i);
172 pp = set_find(arg_set, &templ, sizeof(templ), nodeset_hash(templ.arg));
174 /* If not found, it was an interfering argument */
176 set_irn_n(phi, i, pp->proj);
179 /* register in perm map */
180 pmap_insert(perm_map, pred_bl, perm);
187 #define is_pinned(irn) (get_irn_link(irn))
188 #define get_pinning_block(irn) ((ir_node *)get_irn_link(irn))
189 #define pin_irn(irn, lock) (set_irn_link(irn, lock))
192 * Adjusts the register allocation for the (new) phi-operands
193 * and insert duplicates iff necessary.
195 static void set_regs_or_place_dupls_walker(ir_node *bl, void *data) {
196 be_chordal_env_t *chordal_env = data;
199 /* Consider all phis of this block */
200 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
202 ir_node *arg, *phi_block, *arg_block;
203 const arch_register_t *phi_reg, *arg_reg;
204 const arch_register_class_t *cls;
206 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
208 phi_block = get_nodes_block(phi);
209 phi_reg = get_reg(phi);
210 cls = arch_get_irn_reg_class(get_chordal_arch(chordal_env), phi, -1);
212 /* process all arguments of the phi */
213 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
214 arg = get_irn_n(phi, i);
215 arg_block = get_Block_cfgpred_block(phi_block, i);
216 arg_reg = get_reg(arg);
218 assert(arg_reg && "Register must be set while placing perms");
220 DBG((dbg, LEVEL_1, " for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
222 if(values_interfere(chordal_env->lv, phi, arg)) {
224 Insert a duplicate in arguments block,
225 make it the new phi arg,
227 insert it into schedule,
230 ir_node *dupl = be_new_Copy(cls, chordal_env->irg, arg_block, arg);
232 /* this is commented out because it will fail in case of unknown float */
234 ir_mode *m_phi = get_irn_mode(phi), *m_dupl = get_irn_mode(dupl);
237 Conv signed <-> unsigned is killed on ia32
238 check for: (both int OR both float) AND equal mode sizes
240 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
241 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
242 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
245 set_irn_n(phi, i, dupl);
246 set_reg(dupl, phi_reg);
247 sched_add_after(sched_skip(sched_last(arg_block), 0, sched_skip_cf_predicator, chordal_env->birg->main_env->arch_env), dupl);
248 pin_irn(dupl, phi_block);
249 DBG((dbg, LEVEL_1, " they do interfere: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
250 continue; /* with next argument */
253 if (phi_reg == arg_reg) {
254 /* Phi and arg have the same register, so pin and continue */
255 pin_irn(arg, phi_block);
256 DBG((dbg, LEVEL_1, " arg has same reg: pin %+F(%s)\n", arg, get_reg(arg)->name));
260 DBG((dbg, LEVEL_1, " they do not interfere\n"));
261 assert(is_Proj(arg));
263 First check if there is an other phi
265 - having arg at the current pos in its arg-list
266 - having the same color as arg
268 If found, then pin the arg (for that phi)
270 if (! is_pinned(arg)) {
273 DBG((dbg, LEVEL_1, " searching for phi with same arg having args register\n"));
275 for(other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
277 assert(is_Phi(other_phi) &&
278 get_nodes_block(phi) == get_nodes_block(other_phi) &&
279 "link fields are screwed up");
281 if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
282 DBG((dbg, LEVEL_1, " found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
283 pin_irn(arg, phi_block);
289 if (is_pinned(arg)) {
291 Insert a duplicate of the original value in arguments block,
292 make it the new phi arg,
294 insert it into schedule,
297 ir_node *perm = get_Proj_pred(arg);
298 ir_node *dupl = be_new_Copy(cls, chordal_env->irg, arg_block, arg);
301 /* this is commented out because it will fail in case of unknown float */
303 ir_mode *m_phi = get_irn_mode(phi);
304 ir_mode *m_dupl = get_irn_mode(dupl);
307 Conv signed <-> unsigned is killed on ia32
308 check for: (both int OR both float) AND equal mode sizes
310 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
311 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
312 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
315 set_irn_n(phi, i, dupl);
316 set_reg(dupl, phi_reg);
317 /* skip the Perm's Projs and insert the copies behind. */
318 for(ins = sched_next(perm); is_Proj(ins); ins = sched_next(ins));
319 sched_add_before(ins, dupl);
320 pin_irn(dupl, phi_block);
321 DBG((dbg, LEVEL_1, " arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
324 No other phi has the same color (else arg would have been pinned),
325 so just set the register and pin
327 set_reg(arg, phi_reg);
328 pin_irn(arg, phi_block);
329 DBG((dbg, LEVEL_1, " arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
335 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
336 pmap *perm_map = pmap_create();
337 ir_graph *irg = chordal_env->irg;
339 FIRM_DBG_REGISTER(dbg, "ir.be.ssadestr");
341 /* create a map for fast lookup of perms: block --> perm */
342 chordal_env->data = perm_map;
343 irg_walk_graph(irg, clear_link, collect_phis_walker, chordal_env);
345 DBG((dbg, LEVEL_1, "Placing perms...\n"));
346 irg_block_walk_graph(irg, insert_all_perms_walker, NULL, chordal_env);
348 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
349 be_dump(irg, "-ssa_destr_perms_placed", dump_ir_block_graph_sched);
351 be_liveness_recompute(chordal_env->lv);
353 DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
354 irg_block_walk_graph(irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
356 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
357 be_dump(irg, "-ssa_destr_regs_set", dump_ir_block_graph_sched);
359 pmap_destroy(perm_map);
362 static void ssa_destruction_check_walker(ir_node *bl, void *data) {
363 be_chordal_env_t *chordal_env = data;
367 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
368 const arch_register_t *phi_reg, *arg_reg;
370 phi_reg = get_reg(phi);
371 /* iterate over all args of phi */
372 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
373 ir_node *arg = get_irn_n(phi, i);
375 arg_reg = get_reg(arg);
377 if (phi_reg != arg_reg) {
378 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
382 if (! is_pinned(arg)) {
383 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
390 void be_ssa_destruction_check(be_chordal_env_t *chordal_env) {
391 irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, chordal_env);