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 static firm_dbg_module_t *dbg = NULL;
35 #define get_chordal_arch(ce) ((ce)->main_env->arch_env)
36 #define get_reg(irn) arch_get_irn_register(get_chordal_arch(chordal_env), irn)
37 #define set_reg(irn, reg) arch_set_irn_register(get_chordal_arch(chordal_env), irn, reg)
39 #define is_Perm(irn) (arch_irn_classify(arch_env, irn) == arch_irn_class_perm)
40 #define get_reg_cls(irn) (arch_get_irn_reg_class(arch_env, irn, -1))
41 #define is_curr_reg_class(irn) (get_reg_cls(p) == chordal_env->cls)
43 static void clear_link(ir_node *irn, void *data) {
44 set_irn_link(irn, NULL);
48 * For each block build a linked list of phis that
50 * - have the current register class
51 * The list is rooted at get_irn_link(BB).
53 static void collect_phis_walker(ir_node *irn, void *data) {
54 be_chordal_env_t *env = data;
55 if(is_Phi(irn) && chordal_has_class(env, irn)) {
56 ir_node *bl = get_nodes_block(irn);
57 set_irn_link(irn, get_irn_link(bl));
58 set_irn_link(bl, irn);
63 * This struct represents a Proj for a Perm.
64 * It records the argument in the Perm and the corresponding Proj of the
68 ir_node *arg; /**< The phi argument to make the Proj for. */
69 int pos; /**< The proj number the Proj will get.
70 This also denotes the position of @p arg
71 in the in array of the Perm. */
72 ir_node *proj; /**< The proj created for @p arg. */
75 static int cmp_perm_proj(const void *a, const void *b, size_t n) {
76 const perm_proj_t *p = a;
77 const perm_proj_t *q = b;
78 return !(p->arg == q->arg);
82 * Insert Perms in all predecessors of a block containing a phi
84 static void insert_all_perms_walker(ir_node *bl, void *data) {
85 be_chordal_env_t *chordal_env = data;
86 pmap *perm_map = chordal_env->data;
87 ir_graph *irg = chordal_env->irg;
88 const be_node_factory_t *fact = chordal_env->main_env->node_factory;
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 = HASH_PTR(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 && !is_live_in(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 = malloc(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 = new_Perm(fact, chordal_env->cls, irg, pred_bl, n_projs, in);
144 insert_after = sched_skip(sched_last(pred_bl), 0, sched_skip_cf_predicator, chordal_env->main_env->arch_env);
145 sched_add_after(insert_after, perm);
148 * Make the Projs for the Perm and insert into schedule.
149 * Register allocation is copied from the former phi
150 * arguments to the projs (new phi arguments).
153 for(pp = set_first(arg_set); pp; pp = set_next(arg_set)) {
154 ir_node *proj = new_r_Proj(irg, pred_bl, perm, get_irn_mode(pp->arg), pp->pos);
156 assert(get_reg(pp->arg));
157 set_reg(proj, get_reg(pp->arg));
158 sched_add_after(insert_after, proj);
160 DBG((dbg, LEVEL_2, "Copy register assignment %s from %+F to %+F\n", get_reg(pp->arg)->name, pp->arg, pp->proj));
164 * Set the phi nodes to their new arguments: The Projs of the Perm
166 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
169 templ.arg = get_irn_n(phi, i);
170 pp = set_find(arg_set, &templ, sizeof(templ), HASH_PTR(templ.arg));
172 /* If not found, it was an interfering argument */
174 set_irn_n(phi, i, pp->proj);
177 /* register in perm map */
178 pmap_insert(perm_map, pred_bl, perm);
185 #define is_pinned(irn) (get_irn_link(irn))
186 #define get_pinning_block(irn) ((ir_node *)get_irn_link(irn))
187 #define pin_irn(irn, lock) (set_irn_link(irn, lock))
190 * Adjusts the register allocation for the (new) phi-operands
191 * and insert duplicates iff necessary.
193 static void set_regs_or_place_dupls_walker(ir_node *bl, void *data) {
194 be_chordal_env_t *chordal_env = data;
197 /* Consider all phis of this block */
198 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
200 ir_node *arg, *phi_block, *arg_block;
201 const arch_register_t *phi_reg, *arg_reg;
202 const arch_register_class_t *cls;
204 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
206 phi_block = get_nodes_block(phi);
207 phi_reg = get_reg(phi);
208 cls = arch_get_irn_reg_class(get_chordal_arch(chordal_env), phi, -1);
210 /* process all arguments of the phi */
211 for(i=0, max=get_irn_arity(phi); i<max; ++i) {
212 arg = get_irn_n(phi, i);
213 arg_block = get_Block_cfgpred_block(phi_block, i);
214 arg_reg = get_reg(arg);
215 assert(arg_reg && "Register must be set while placing perms");
217 DBG((dbg, LEVEL_1, " for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
219 if(nodes_interfere(chordal_env, 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 = new_Copy(chordal_env->main_env->node_factory, cls, chordal_env->irg, arg_block, arg);
227 assert(get_irn_mode(phi) == get_irn_mode(dupl));
228 set_irn_n(phi, i, dupl);
229 set_reg(dupl, phi_reg);
230 sched_add_after(sched_skip(sched_last(arg_block), 0, sched_skip_cf_predicator, chordal_env->main_env->arch_env), dupl);
231 pin_irn(dupl, phi_block);
232 DBG((dbg, LEVEL_1, " they do interfere: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
233 continue; /* with next argument */
236 if (phi_reg == arg_reg) {
237 /* Phi and arg have the same register,
238 * so pin and continue
240 pin_irn(arg, phi_block);
241 DBG((dbg, LEVEL_1, " arg has same reg: pin %+F(%s)\n", arg, get_reg(arg)->name));
245 DBG((dbg, LEVEL_1, " they do not interfere\n"));
246 assert(is_Proj(arg));
248 * First check if there is an other phi
249 * - in the same block
250 * - having arg at the current pos in its arg-list
251 * - having the same color as arg
253 * If found, then pin the arg (for that phi)
255 if (!is_pinned(arg)) {
257 DBG((dbg, LEVEL_1, " searching for phi with same arg having args register\n"));
258 for(other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
259 assert(is_Phi(other_phi) && get_nodes_block(phi) == get_nodes_block(other_phi) && "link fields are screwed up");
260 if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
261 DBG((dbg, LEVEL_1, " found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
262 pin_irn(arg, phi_block);
268 if (is_pinned(arg)) {
269 /* Insert a duplicate of the original value in arguments block,
270 * make it the new phi arg,
272 * insert it into schedule,
275 ir_node *perm = get_Proj_pred(arg);
276 ir_node *orig_val = get_irn_n(perm, get_Proj_proj(arg));
277 ir_node *dupl = new_Copy(chordal_env->main_env->node_factory, cls, chordal_env->irg, arg_block, orig_val);
278 assert(get_irn_mode(phi) == get_irn_mode(dupl));
279 set_irn_n(phi, i, dupl);
280 set_reg(dupl, phi_reg);
281 sched_add_before(perm, dupl);
282 pin_irn(dupl, phi_block);
283 DBG((dbg, LEVEL_1, " arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
285 /* No other phi has the same color (else arg would have been pinned),
286 * so just set the register and pin
288 set_reg(arg, phi_reg);
289 pin_irn(arg, phi_block);
290 DBG((dbg, LEVEL_1, " arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
296 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
297 pmap *perm_map = pmap_create();
298 ir_graph *irg = chordal_env->irg;
300 dbg = firm_dbg_register("ir.be.ssadestr");
302 /* create a map for fast lookup of perms: block --> perm */
303 chordal_env->data = perm_map;
304 irg_walk_graph(irg, clear_link, collect_phis_walker, chordal_env);
306 DBG((dbg, LEVEL_1, "Placing perms...\n"));
307 irg_block_walk_graph(irg, insert_all_perms_walker, NULL, chordal_env);
309 dump_ir_block_graph_sched(irg, "-ssa_destr_perms_placed");
312 DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
313 irg_block_walk_graph(irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
315 dump_ir_block_graph_sched(irg, "-ssa_destr_regs_set");
318 pmap_destroy(perm_map);
321 static void ssa_destruction_check_walker(ir_node *bl, void *data) {
322 be_chordal_env_t *chordal_env = data;
326 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
327 const arch_register_t *phi_reg, *arg_reg;
329 phi_reg = get_reg(phi);
330 /* iterate over all args of phi */
331 for(i=0, max=get_irn_arity(phi); i<max; ++i) {
332 ir_node *arg = get_irn_n(phi, i);
333 arg_reg = get_reg(arg);
334 if(phi_reg != arg_reg) {
335 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
338 if(!is_pinned(arg)) {
339 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
346 void be_ssa_destruction_check(be_chordal_env_t *chordal_env) {
347 irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, chordal_env);