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);
82 typedef struct insert_all_perms_env_t {
83 be_chordal_env_t *chordal_env;
85 } insert_all_perms_env_t;
88 * Insert Perms in all predecessors of a block containing a phi
90 static void insert_all_perms_walker(ir_node *bl, void *data) {
91 insert_all_perms_env_t *env = data;
92 be_chordal_env_t *chordal_env = env->chordal_env;
93 pmap *perm_map = env->perm_map;
94 ir_graph *irg = chordal_env->irg;
95 be_lv_t *lv = chordal_env->birg->lv;
100 /* If the link flag is NULL, this block has no phis. */
101 if(!get_irn_link(bl))
104 /* Look at all predecessors of the phi block */
105 for(i = 0, n = get_irn_arity(bl); i < n; ++i) {
106 ir_node *phi, *perm, *insert_after, **in;
108 set *arg_set = new_set(cmp_perm_proj, chordal_env->cls->n_regs);
109 ir_node *pred_bl = get_Block_cfgpred_block(bl, i);
112 assert(!pmap_contains(perm_map, pred_bl) && "Already permed that block");
115 * Note that all phis in the list are in the same
116 * register class by construction.
118 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
120 ir_node *arg = get_irn_n(phi, i);
121 unsigned hash = nodeset_hash(arg);
124 pp = set_find(arg_set, &templ, sizeof(templ), hash);
127 * If a proj_perm_t entry has not been made in the argument set,
128 * create one. The only restriction is, that the phi argument
129 * may not be live in at the current block, since this argument
130 * interferes with the phi and must thus not be member of a
131 * Perm. A copy will be inserted for this argument alter on.
133 if(!pp && !be_is_live_in(lv, bl, arg)) {
134 templ.pos = n_projs++;
135 set_insert(arg_set, &templ, sizeof(templ), hash);
142 * Create a new Perm with the arguments just collected
143 * above in the arg_set and insert it into the schedule.
145 in = xmalloc(n_projs * sizeof(in[0]));
146 for(pp = set_first(arg_set); pp; pp = set_next(arg_set))
147 in[pp->pos] = pp->arg;
149 perm = be_new_Perm(chordal_env->cls, irg, pred_bl, n_projs, in);
150 be_stat_ev("phi_perm", n_projs);
153 insert_after = sched_skip(sched_last(pred_bl), 0, sched_skip_cf_predicator, chordal_env->birg->main_env->arch_env);
154 sched_add_after(insert_after, perm);
157 * Make the Projs for the Perm and insert into schedule.
158 * Register allocation is copied from the former phi
159 * arguments to the projs (new phi arguments).
162 for(pp = set_first(arg_set); pp; pp = set_next(arg_set)) {
163 ir_node *proj = new_r_Proj(irg, pred_bl, perm, get_irn_mode(pp->arg), pp->pos);
165 assert(get_reg(pp->arg));
166 set_reg(proj, get_reg(pp->arg));
167 sched_add_after(insert_after, proj);
169 DBG((dbg, LEVEL_2, "Copy register assignment %s from %+F to %+F\n", get_reg(pp->arg)->name, pp->arg, pp->proj));
173 * Set the phi nodes to their new arguments: The Projs of the Perm
175 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
178 templ.arg = get_irn_n(phi, i);
179 pp = set_find(arg_set, &templ, sizeof(templ), nodeset_hash(templ.arg));
181 /* If not found, it was an interfering argument */
183 set_irn_n(phi, i, pp->proj);
186 /* register in perm map */
187 pmap_insert(perm_map, pred_bl, perm);
194 #define is_pinned(irn) (get_irn_link(irn))
195 #define get_pinning_block(irn) ((ir_node *)get_irn_link(irn))
196 #define pin_irn(irn, lock) (set_irn_link(irn, lock))
199 * Adjusts the register allocation for the (new) phi-operands
200 * and insert duplicates iff necessary.
202 static void set_regs_or_place_dupls_walker(ir_node *bl, void *data) {
203 be_chordal_env_t *chordal_env = data;
204 be_lv_t *lv = chordal_env->birg->lv;
207 /* Consider all phis of this block */
208 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
210 ir_node *arg, *phi_block, *arg_block;
211 const arch_register_t *phi_reg, *arg_reg;
212 const arch_register_class_t *cls;
214 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
216 phi_block = get_nodes_block(phi);
217 phi_reg = get_reg(phi);
218 cls = arch_get_irn_reg_class(get_chordal_arch(chordal_env), phi, -1);
220 /* process all arguments of the phi */
221 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
222 arg = get_irn_n(phi, i);
223 arg_block = get_Block_cfgpred_block(phi_block, i);
224 arg_reg = get_reg(arg);
226 assert(arg_reg && "Register must be set while placing perms");
228 DBG((dbg, LEVEL_1, " for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
230 if(values_interfere(lv, phi, arg)) {
232 Insert a duplicate in arguments block,
233 make it the new phi arg,
235 insert it into schedule,
238 ir_node *dupl = be_new_Copy(cls, chordal_env->irg, arg_block, arg);
240 /* this is commented out because it will fail in case of unknown float */
242 ir_mode *m_phi = get_irn_mode(phi), *m_dupl = get_irn_mode(dupl);
245 Conv signed <-> unsigned is killed on ia32
246 check for: (both int OR both float) AND equal mode sizes
248 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
249 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
250 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
253 set_irn_n(phi, i, dupl);
254 set_reg(dupl, phi_reg);
255 sched_add_after(sched_skip(sched_last(arg_block), 0, sched_skip_cf_predicator, chordal_env->birg->main_env->arch_env), dupl);
256 pin_irn(dupl, phi_block);
257 DBG((dbg, LEVEL_1, " they do interfere: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
258 continue; /* with next argument */
261 if (phi_reg == arg_reg) {
262 /* Phi and arg have the same register, so pin and continue */
263 pin_irn(arg, phi_block);
264 DBG((dbg, LEVEL_1, " arg has same reg: pin %+F(%s)\n", arg, get_reg(arg)->name));
268 DBG((dbg, LEVEL_1, " they do not interfere\n"));
269 assert(is_Proj(arg));
271 First check if there is an other phi
273 - having arg at the current pos in its arg-list
274 - having the same color as arg
276 If found, then pin the arg (for that phi)
278 if (! is_pinned(arg)) {
281 DBG((dbg, LEVEL_1, " searching for phi with same arg having args register\n"));
283 for(other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
285 assert(is_Phi(other_phi) &&
286 get_nodes_block(phi) == get_nodes_block(other_phi) &&
287 "link fields are screwed up");
289 if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
290 DBG((dbg, LEVEL_1, " found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
291 pin_irn(arg, phi_block);
297 if (is_pinned(arg)) {
299 Insert a duplicate of the original value in arguments block,
300 make it the new phi arg,
302 insert it into schedule,
305 ir_node *perm = get_Proj_pred(arg);
306 ir_node *dupl = be_new_Copy(cls, chordal_env->irg, arg_block, arg);
309 /* this is commented out because it will fail in case of unknown float */
311 ir_mode *m_phi = get_irn_mode(phi);
312 ir_mode *m_dupl = get_irn_mode(dupl);
315 Conv signed <-> unsigned is killed on ia32
316 check for: (both int OR both float) AND equal mode sizes
318 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
319 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
320 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
323 set_irn_n(phi, i, dupl);
324 set_reg(dupl, phi_reg);
325 /* skip the Perm's Projs and insert the copies behind. */
326 for(ins = sched_next(perm); is_Proj(ins); ins = sched_next(ins));
327 sched_add_before(ins, dupl);
328 pin_irn(dupl, phi_block);
329 DBG((dbg, LEVEL_1, " arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
332 No other phi has the same color (else arg would have been pinned),
333 so just set the register and pin
335 set_reg(arg, phi_reg);
336 pin_irn(arg, phi_block);
337 DBG((dbg, LEVEL_1, " arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
343 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
344 pmap *perm_map = pmap_create();
345 ir_graph *irg = chordal_env->irg;
346 insert_all_perms_env_t insert_perms_env;
348 FIRM_DBG_REGISTER(dbg, "ir.be.ssadestr");
350 be_assure_liveness(chordal_env->birg);
352 /* create a map for fast lookup of perms: block --> perm */
353 irg_walk_graph(irg, clear_link, collect_phis_walker, chordal_env);
355 DBG((dbg, LEVEL_1, "Placing perms...\n"));
356 insert_perms_env.chordal_env = chordal_env;
357 insert_perms_env.perm_map = perm_map;
358 irg_block_walk_graph(irg, insert_all_perms_walker, NULL, &insert_perms_env);
360 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
361 be_dump(irg, "-ssa_destr_perms_placed", dump_ir_block_graph_sched);
363 // Matze: really needed here?
364 be_invalidate_liveness(chordal_env->birg);
365 be_assure_liveness(chordal_env->birg);
367 DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
368 irg_block_walk_graph(irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
370 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
371 be_dump(irg, "-ssa_destr_regs_set", dump_ir_block_graph_sched);
373 pmap_destroy(perm_map);
376 static void ssa_destruction_check_walker(ir_node *bl, void *data) {
377 be_chordal_env_t *chordal_env = data;
381 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
382 const arch_register_t *phi_reg, *arg_reg;
384 phi_reg = get_reg(phi);
385 /* iterate over all args of phi */
386 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
387 ir_node *arg = get_irn_n(phi, i);
389 arg_reg = get_reg(arg);
391 if (phi_reg != arg_reg) {
392 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
396 if (! is_pinned(arg)) {
397 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
404 void be_ssa_destruction_check(be_chordal_env_t *chordal_env) {
405 irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, chordal_env);