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"
25 #include "bechordal_t.h"
29 #include "besched_t.h"
31 static firm_dbg_module_t *dbg = NULL;
32 #define DEBUG_LVL SET_LEVEL_0
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)
45 set_irn_link(irn, NULL);
49 * Build a list of phis of a block.
51 static void collect_phis(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 * Build a ring of phis for each block in the link field.
63 * @param env The chordal env.
65 static INLINE void build_phi_rings(be_chordal_env_t *env)
67 irg_walk_graph(env->irg, clear_link, collect_phis, env);
70 static void insert_all_perms_walker(ir_node *bl, void *data)
72 be_chordal_env_t *chordal_env = data;
73 pmap *perm_map = chordal_env->data;
74 ir_graph *irg = chordal_env->irg;
75 const be_node_factory_t *fact = chordal_env->main_env->node_factory;
77 /* Dummy targets for the projs */
78 ir_node *dummy = new_rd_Unknown(irg, mode_T);
82 /* If the link flag is NULL, this block has no phis. */
83 if(get_irn_link(bl)) {
86 /* Look at all predecessors of the phi block */
87 for(i = 0, n = get_irn_arity(bl); i < n; ++i) {
88 ir_node *pred_bl = get_Block_cfgpred_block(bl, i);
89 ir_node *phi, *perm, *insert_after;
93 pmap *arg_map = pmap_create();
95 assert(!pmap_contains(perm_map, pred_bl) && "Already permed that block");
98 * Note that all phis in the list are in the same register class
101 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
102 ir_node *arg = get_irn_n(phi, i);
103 ir_node *proj = pmap_get(arg_map, arg);
105 if(!proj && !is_live_in(bl, arg)) {
106 proj = new_r_Proj(irg, pred_bl, dummy, get_irn_mode(arg), n_projs++);
107 pmap_insert(arg_map, arg, proj);
111 assert(get_irn_mode(phi) == get_irn_mode(proj));
112 set_irn_n(phi, i, proj);
116 in = malloc(n_projs * sizeof(in[0]));
117 pmap_foreach(arg_map, ent) {
118 int proj_nr = get_Proj_proj(ent->value);
119 in[proj_nr] = ent->key;
122 perm = new_Perm(fact, chordal_env->cls, irg, pred_bl, n_projs, in);
123 insert_after = sched_skip(sched_last(pred_bl), 0, sched_skip_cf_predicator, chordal_env->main_env->arch_env);
124 sched_add_after(insert_after, perm);
125 exchange(dummy, perm);
127 /* register allocation is copied form former arguments to the projs (new arguments) */
128 pmap_foreach(arg_map, ent) {
129 DBG((dbg, LEVEL_2, "Copy register assignment %s from %+F to %+F\n", get_reg(ent->key)->name, ent->key, ent->value));
130 set_reg(ent->value, get_reg(ent->key));
134 pmap_destroy(arg_map);
136 /* register in perm map */
137 pmap_insert(perm_map, pred_bl, perm);
142 static void insert_all_perms(be_chordal_env_t *chordal_env) {
143 DBG((dbg, LEVEL_1, "Placing perms...\n"));
144 irg_block_walk_graph(chordal_env->irg, insert_all_perms_walker, NULL, chordal_env);
147 #define is_pinned(irn) (get_irn_link(irn))
148 #define get_pinning_block(irn) ((ir_node *)get_irn_link(irn))
149 #define pin_irn(irn, lock) (set_irn_link(irn, lock))
153 * Adjusts the register allocation for the phi-operands
154 * by inserting perm nodes, if necessary.
155 * @param phi The phi node to adjust operands for
157 static void adjust_phi_arguments(be_chordal_env_t *chordal_env, ir_node *phi) {
159 ir_node *arg, *phi_block, *arg_block;
160 const arch_register_t *phi_reg, *arg_reg;
161 const arch_register_class_t *cls;
163 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
165 phi_block = get_nodes_block(phi);
166 phi_reg = get_reg(phi);
167 cls = arch_get_irn_reg_class(get_chordal_arch(chordal_env), phi, -1);
169 /* process all arguments of the phi */
170 for(i=0, max=get_irn_arity(phi); i<max; ++i) {
171 arg = get_irn_n(phi, i);
172 arg_block = get_Block_cfgpred_block(phi_block, i);
173 arg_reg = get_reg(arg);
174 assert(arg_reg && "Register must be set while placing perms");
176 DBG((dbg, LEVEL_1, " for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
178 if(nodes_interfere(chordal_env, phi, arg)) {
179 /* Insert a duplicate in arguments block,
180 * make it the new phi arg,
182 * insert it into schedule,
185 ir_node *dupl = new_Copy(chordal_env->main_env->node_factory, cls, chordal_env->irg, arg_block, arg);
186 assert(get_irn_mode(phi) == get_irn_mode(dupl));
187 set_irn_n(phi, i, dupl);
188 set_reg(dupl, phi_reg);
189 sched_add_after(sched_skip(sched_last(arg_block), 0, sched_skip_cf_predicator, chordal_env->main_env->arch_env), dupl);
190 pin_irn(dupl, phi_block);
191 DBG((dbg, LEVEL_1, " they do interfere: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
194 * First check if there is a phi
195 * - in the same block
196 * - having arg at the current pos in its arg-list
197 * - having the same color as arg
199 * If found, then pin the arg
201 DBG((dbg, LEVEL_1, " they do not interfere\n"));
202 assert(is_Proj(arg));
203 if (!is_pinned(arg)) {
205 DBG((dbg, LEVEL_1, " searching for phi with same arg having args register\n"));
206 for(other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
207 assert(is_Phi(other_phi) && get_nodes_block(phi) == get_nodes_block(other_phi) && "link fields are screwed up");
208 if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
209 DBG((dbg, LEVEL_1, " found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
210 pin_irn(arg, phi_block);
215 if (is_pinned(arg)) {
216 /* Insert a duplicate of the original value in arguments block,
217 * make it the new phi arg,
219 * insert it into schedule,
222 ir_node *perm = get_Proj_pred(arg);
223 ir_node *orig_val = get_irn_n(perm, get_Proj_proj(arg));
224 ir_node *dupl = new_Copy(chordal_env->main_env->node_factory, cls, chordal_env->irg, arg_block, orig_val);
225 assert(get_irn_mode(phi) == get_irn_mode(dupl));
226 set_irn_n(phi, i, dupl);
227 set_reg(dupl, phi_reg);
228 sched_add_before(perm, dupl);
229 pin_irn(dupl, phi_block);
230 DBG((dbg, LEVEL_1, " arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
232 /* No other phi has the same color (else arg would be pinned),
233 * so just set the register and pin
235 set_reg(arg, phi_reg);
236 pin_irn(arg, phi_block);
237 DBG((dbg, LEVEL_1, " arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
243 static void set_regs_or_place_dupls_walker(ir_node *bl, void *data) {
244 be_chordal_env_t *chordal_env = data;
247 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi))
248 adjust_phi_arguments(chordal_env, phi);
251 static void set_regs_or_place_dupls(be_chordal_env_t *chordal_env)
253 DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
254 irg_block_walk_graph(chordal_env->irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
258 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
259 pmap *perm_map = pmap_create();
260 ir_graph *irg = chordal_env->irg;
262 dbg = firm_dbg_register("ir.be.ssadestr");
263 firm_dbg_set_mask(dbg, DEBUG_LVL);
265 /* create a map for fast lookup of perms: block --> perm */
266 chordal_env->data = perm_map;
268 build_phi_rings(chordal_env);
269 insert_all_perms(chordal_env);
271 dump_ir_block_graph_sched(irg, "-ssa_destr_perms_placed");
273 set_regs_or_place_dupls(chordal_env);
275 dump_ir_block_graph_sched(irg, "-ssa_destr_regs_set");
278 pmap_destroy(perm_map);
281 static void ssa_destruction_check_walker(ir_node *bl, void *data)
283 be_chordal_env_t *chordal_env = data;
287 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
288 const arch_register_t *phi_reg, *arg_reg;
290 phi_reg = get_reg(phi);
291 /* iterate over all args of phi */
292 for(i=0, max=get_irn_arity(phi); i<max; ++i) {
293 ir_node *arg = get_irn_n(phi, i);
294 arg_reg = get_reg(arg);
295 if(phi_reg != arg_reg) {
296 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
299 if(!is_pinned(arg)) {
300 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
307 void be_ssa_destruction_check(be_chordal_env_t *chordal_env) {
308 irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, chordal_env);