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"
32 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
34 #define get_chordal_arch(ce) ((ce)->birg->main_env->arch_env)
35 #define get_reg(irn) arch_get_irn_register(get_chordal_arch(chordal_env), irn)
36 #define set_reg(irn, reg) arch_set_irn_register(get_chordal_arch(chordal_env), irn, reg)
38 #define is_Perm(irn) (arch_irn_classify(arch_env, irn) == arch_irn_class_perm)
39 #define get_reg_cls(irn) (arch_get_irn_reg_class(arch_env, irn, -1))
40 #define is_curr_reg_class(irn) (get_reg_cls(p) == chordal_env->cls)
42 static void clear_link(ir_node *irn, void *data) {
43 set_irn_link(irn, NULL);
47 * For each block build a linked list of phis that
49 * - have the current register class
50 * The list is rooted at get_irn_link(BB).
52 static void collect_phis_walker(ir_node *irn, void *data) {
53 be_chordal_env_t *env = data;
54 if(is_Phi(irn) && chordal_has_class(env, irn)) {
55 ir_node *bl = get_nodes_block(irn);
56 set_irn_link(irn, get_irn_link(bl));
57 set_irn_link(bl, irn);
62 * This struct represents a Proj for a Perm.
63 * It records the argument in the Perm and the corresponding Proj of the
67 ir_node *arg; /**< The phi argument to make the Proj for. */
68 int pos; /**< The proj number the Proj will get.
69 This also denotes the position of @p arg
70 in the in array of the Perm. */
71 ir_node *proj; /**< The proj created for @p arg. */
74 static int cmp_perm_proj(const void *a, const void *b, size_t n) {
75 const perm_proj_t *p = a;
76 const perm_proj_t *q = b;
77 return !(p->arg == q->arg);
81 * Insert Perms in all predecessors of a block containing a phi
83 static void insert_all_perms_walker(ir_node *bl, void *data) {
84 be_chordal_env_t *chordal_env = data;
85 pmap *perm_map = chordal_env->data;
86 ir_graph *irg = chordal_env->irg;
91 /* If the link flag is NULL, this block has no phis. */
95 /* Look at all predecessors of the phi block */
96 for(i = 0, n = get_irn_arity(bl); i < n; ++i) {
97 ir_node *phi, *perm, *insert_after, **in;
99 set *arg_set = new_set(cmp_perm_proj, chordal_env->cls->n_regs);
100 ir_node *pred_bl = get_Block_cfgpred_block(bl, i);
103 assert(!pmap_contains(perm_map, pred_bl) && "Already permed that block");
106 * Note that all phis in the list are in the same
107 * register class by construction.
109 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
111 ir_node *arg = get_irn_n(phi, i);
112 unsigned hash = HASH_PTR(arg);
115 pp = set_find(arg_set, &templ, sizeof(templ), hash);
118 * If a proj_perm_t entry has not been made in the argument set,
119 * create one. The only restriction is, that the phi argument
120 * may not be live in at the current block, since this argument
121 * interferes with the phi and must thus not be member of a
122 * Perm. A copy will be inserted for this argument alter on.
124 if(!pp && !is_live_in(bl, arg)) {
125 templ.pos = n_projs++;
126 set_insert(arg_set, &templ, sizeof(templ), hash);
133 * Create a new Perm with the arguments just collected
134 * above in the arg_set and insert it into the schedule.
136 in = xmalloc(n_projs * sizeof(in[0]));
137 for(pp = set_first(arg_set); pp; pp = set_next(arg_set))
138 in[pp->pos] = pp->arg;
140 perm = be_new_Perm(chordal_env->cls, irg, pred_bl, n_projs, in);
142 insert_after = sched_skip(sched_last(pred_bl), 0, sched_skip_cf_predicator, chordal_env->birg->main_env->arch_env);
143 sched_add_after(insert_after, perm);
146 * Make the Projs for the Perm and insert into schedule.
147 * Register allocation is copied from the former phi
148 * arguments to the projs (new phi arguments).
151 for(pp = set_first(arg_set); pp; pp = set_next(arg_set)) {
152 ir_node *proj = new_r_Proj(irg, pred_bl, perm, get_irn_mode(pp->arg), pp->pos);
154 assert(get_reg(pp->arg));
155 set_reg(proj, get_reg(pp->arg));
156 sched_add_after(insert_after, proj);
158 DBG((dbg, LEVEL_2, "Copy register assignment %s from %+F to %+F\n", get_reg(pp->arg)->name, pp->arg, pp->proj));
162 * Set the phi nodes to their new arguments: The Projs of the Perm
164 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
167 templ.arg = get_irn_n(phi, i);
168 pp = set_find(arg_set, &templ, sizeof(templ), HASH_PTR(templ.arg));
170 /* If not found, it was an interfering argument */
172 set_irn_n(phi, i, pp->proj);
175 /* register in perm map */
176 pmap_insert(perm_map, pred_bl, perm);
183 #define is_pinned(irn) (get_irn_link(irn))
184 #define get_pinning_block(irn) ((ir_node *)get_irn_link(irn))
185 #define pin_irn(irn, lock) (set_irn_link(irn, lock))
188 * Adjusts the register allocation for the (new) phi-operands
189 * and insert duplicates iff necessary.
191 static void set_regs_or_place_dupls_walker(ir_node *bl, void *data) {
192 be_chordal_env_t *chordal_env = data;
195 /* Consider all phis of this block */
196 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
198 ir_node *arg, *phi_block, *arg_block;
199 const arch_register_t *phi_reg, *arg_reg;
200 const arch_register_class_t *cls;
202 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
204 phi_block = get_nodes_block(phi);
205 phi_reg = get_reg(phi);
206 cls = arch_get_irn_reg_class(get_chordal_arch(chordal_env), phi, -1);
208 /* process all arguments of the phi */
209 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
210 arg = get_irn_n(phi, i);
211 arg_block = get_Block_cfgpred_block(phi_block, i);
212 arg_reg = get_reg(arg);
214 assert(arg_reg && "Register must be set while placing perms");
216 DBG((dbg, LEVEL_1, " for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
218 if(values_interfere(phi, arg)) {
220 Insert a duplicate in arguments block,
221 make it the new phi arg,
223 insert it into schedule,
226 ir_node *dupl = be_new_Copy(cls, chordal_env->irg, arg_block, arg);
228 /* this is commented out because it will fail in case of unknown float */
230 ir_mode *m_phi = get_irn_mode(phi), *m_dupl = get_irn_mode(dupl);
233 Conv signed <-> unsigned is killed on ia32
234 check for: (both int OR both float) AND equal mode sizes
236 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
237 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
238 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
241 set_irn_n(phi, i, dupl);
242 set_reg(dupl, phi_reg);
243 sched_add_after(sched_skip(sched_last(arg_block), 0, sched_skip_cf_predicator, chordal_env->birg->main_env->arch_env), dupl);
244 pin_irn(dupl, phi_block);
245 DBG((dbg, LEVEL_1, " they do interfere: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
246 continue; /* with next argument */
249 if (phi_reg == arg_reg) {
250 /* Phi and arg have the same register, so pin and continue */
251 pin_irn(arg, phi_block);
252 DBG((dbg, LEVEL_1, " arg has same reg: pin %+F(%s)\n", arg, get_reg(arg)->name));
256 DBG((dbg, LEVEL_1, " they do not interfere\n"));
257 assert(is_Proj(arg));
259 First check if there is an other phi
261 - having arg at the current pos in its arg-list
262 - having the same color as arg
264 If found, then pin the arg (for that phi)
266 if (! is_pinned(arg)) {
269 DBG((dbg, LEVEL_1, " searching for phi with same arg having args register\n"));
271 for(other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
273 assert(is_Phi(other_phi) &&
274 get_nodes_block(phi) == get_nodes_block(other_phi) &&
275 "link fields are screwed up");
277 if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
278 DBG((dbg, LEVEL_1, " found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
279 pin_irn(arg, phi_block);
285 if (is_pinned(arg)) {
287 Insert a duplicate of the original value in arguments block,
288 make it the new phi arg,
290 insert it into schedule,
293 ir_node *perm = get_Proj_pred(arg);
294 ir_node *orig_val = get_irn_n(perm, get_Proj_proj(arg));
295 ir_node *dupl = be_new_Copy(cls, chordal_env->irg, arg_block, orig_val);
297 /* this is commented out because it will fail in case of unknown float */
299 ir_mode *m_phi = get_irn_mode(phi);
300 ir_mode *m_dupl = get_irn_mode(dupl);
303 Conv signed <-> unsigned is killed on ia32
304 check for: (both int OR both float) AND equal mode sizes
306 assert(((mode_is_int(m_phi) && mode_is_int(m_dupl)) ||
307 (mode_is_float(m_phi) && mode_is_float(m_dupl))) &&
308 (get_mode_size_bits(m_phi) == get_mode_size_bits(m_dupl)));
311 set_irn_n(phi, i, dupl);
312 set_reg(dupl, phi_reg);
313 sched_add_before(perm, dupl);
314 pin_irn(dupl, phi_block);
315 DBG((dbg, LEVEL_1, " arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
318 No other phi has the same color (else arg would have been pinned),
319 so just set the register and pin
321 set_reg(arg, phi_reg);
322 pin_irn(arg, phi_block);
323 DBG((dbg, LEVEL_1, " arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
329 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
330 pmap *perm_map = pmap_create();
331 ir_graph *irg = chordal_env->irg;
333 FIRM_DBG_REGISTER(dbg, "ir.be.ssadestr");
335 /* create a map for fast lookup of perms: block --> perm */
336 chordal_env->data = perm_map;
337 irg_walk_graph(irg, clear_link, collect_phis_walker, chordal_env);
339 DBG((dbg, LEVEL_1, "Placing perms...\n"));
340 irg_block_walk_graph(irg, insert_all_perms_walker, NULL, chordal_env);
342 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
343 be_dump(irg, "-ssa_destr_perms_placed", dump_ir_block_graph_sched);
347 DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
348 irg_block_walk_graph(irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
350 if (chordal_env->opts->dump_flags & BE_CH_DUMP_SSADESTR)
351 be_dump(irg, "-ssa_destr_regs_set", dump_ir_block_graph_sched);
353 pmap_destroy(perm_map);
356 static void ssa_destruction_check_walker(ir_node *bl, void *data) {
357 be_chordal_env_t *chordal_env = data;
361 for (phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
362 const arch_register_t *phi_reg, *arg_reg;
364 phi_reg = get_reg(phi);
365 /* iterate over all args of phi */
366 for (i = 0, max = get_irn_arity(phi); i < max; ++i) {
367 ir_node *arg = get_irn_n(phi, i);
369 arg_reg = get_reg(arg);
371 if (phi_reg != arg_reg) {
372 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
376 if (! is_pinned(arg)) {
377 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
384 void be_ssa_destruction_check(be_chordal_env_t *chordal_env) {
385 irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, chordal_env);