nsz Git - libfirm/blob - ir/be/bessadestr.c

   1 /**
   2  * Author:      Daniel Grund
   3  * Date:                25.05.2005
   4  * Copyright:   (c) Universitaet Karlsruhe
   5  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
   6  *
   7  * Performs SSA-Destruction.
   8  */
   9 #ifdef HAVE_CONFIG_H
  10 #include "config.h"
  11 #endif
  12
  13 #include "debug.h"
  14 #include "set.h"
  15 #include "pmap.h"
  16 #include "irnode_t.h"
  17 #include "ircons_t.h"
  18 #include "iredges_t.h"
  19 #include "irgwalk.h"
  20 #include "irgmod.h"
  21 #include "irdump.h"
  22 #include "irprintf.h"
  23
  24 #include "be_t.h"
  25 #include "beutil.h"
  26 #include "bechordal_t.h"
  27 #include "bearch.h"
  28 #include "belive_t.h"
  29 #include "benode_t.h"
  30 #include "besched_t.h"
  31
  32 static firm_dbg_module_t *dbg = NULL;
  33 #define DUMP_GRAPHS
  34
  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)
  38
  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)
  42
  43 static void clear_link(ir_node *irn, void *data) {
  44         set_irn_link(irn, NULL);
  45 }
  46
  47 /**
  48  * For each block build a linked list of phis that
  49  *  - are in that block
  50  *  - have the current register class
  51  * The list is rooted at get_irn_link(BB).
  52  */
  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);
  59         }
  60 }
  61
  62 /**
  63  * This struct represents a Proj for a Perm.
  64  * It records the argument in the Perm and the corresponding Proj of the
  65  * Perm.
  66  */
  67 typedef struct {
  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. */
  73 } perm_proj_t;
  74
  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);
  79 }
  80
  81 /**
  82  * Insert Perms in all predecessors of a block containing a phi
  83  */
  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;
  89         int i, n;
  90
  91         assert(is_Block(bl));
  92
  93         /* If the link flag is NULL, this block has no phis. */
  94         if(!get_irn_link(bl))
  95                 return;
  96
  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;
 100                 perm_proj_t *pp;
 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);
 103                 int n_projs      = 0;
 104
 105                 assert(!pmap_contains(perm_map, pred_bl) && "Already permed that block");
 106
 107                 /*
 108                  * Note that all phis in the list are in the same
 109                  * register class by construction.
 110                  */
 111                 for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
 112                         perm_proj_t templ;
 113                         ir_node *arg     = get_irn_n(phi, i);
 114                         unsigned hash    = HASH_PTR(arg);
 115
 116                         templ.arg  = arg;
 117                         pp         = set_find(arg_set, &templ, sizeof(templ), hash);
 118
 119                         /*
 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.
 125                          */
 126                         if(!pp && !is_live_in(bl, arg)) {
 127                                 templ.pos = n_projs++;
 128                                 set_insert(arg_set, &templ, sizeof(templ), hash);
 129                         }
 130                 }
 131
 132
 133                 if (n_projs) {
 134                         /*
 135                          * Create a new Perm with the arguments just collected
 136                          * above in the arg_set and insert it into the schedule.
 137                          */
 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;
 141
 142                         perm = new_Perm(fact, chordal_env->cls, irg, pred_bl, n_projs, in);
 143                         free(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);
 146
 147                         /*
 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).
 151                          */
 152                         insert_after = perm;
 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);
 155                                 pp->proj = proj;
 156                                 assert(get_reg(pp->arg));
 157                                 set_reg(proj, get_reg(pp->arg));
 158                                 sched_add_after(insert_after, proj);
 159                                 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));
 161                         }
 162
 163                         /*
 164                          * Set the phi nodes to their new arguments: The Projs of the Perm
 165                          */
 166                         for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
 167                                 perm_proj_t templ;
 168
 169                                 templ.arg = get_irn_n(phi, i);
 170                                 pp        = set_find(arg_set, &templ, sizeof(templ), HASH_PTR(templ.arg));
 171
 172                                 /* If not found, it was an interfering argument */
 173                                 if (pp)
 174                                         set_irn_n(phi, i, pp->proj);
 175                         }
 176
 177                         /* register in perm map */
 178                         pmap_insert(perm_map, pred_bl, perm);
 179                 }
 180
 181                 del_set(arg_set);
 182         }
 183 }
 184
 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))
 188
 189 /**
 190  * Adjusts the register allocation for the (new) phi-operands
 191  * and insert duplicates iff necessary.
 192  */
 193 static void     set_regs_or_place_dupls_walker(ir_node *bl, void *data) {
 194         be_chordal_env_t *chordal_env = data;
 195         ir_node *phi;
 196
 197         /* Consider all phis of this block */
 198         for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
 199                 int i, max;
 200                 ir_node *arg, *phi_block, *arg_block;
 201                 const arch_register_t *phi_reg, *arg_reg;
 202                 const arch_register_class_t *cls;
 203
 204                 assert(is_Phi(phi) && "Can only handle phi-destruction :)");
 205
 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);
 209
 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");
 216
 217                         DBG((dbg, LEVEL_1, "  for %+F(%s) -- %+F(%s)\n", phi, phi_reg->name, arg, arg_reg->name));
 218
 219                         if(nodes_interfere(chordal_env, phi, arg)) {
 220                                 /* Insert a duplicate in arguments block,
 221                                  * make it the new phi arg,
 222                                  * set its register,
 223                                  * insert it into schedule,
 224                                  * pin it
 225                                  */
 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                         } else {
 234                                 if (phi_reg == arg_reg) {
 235                                         pin_irn(arg, phi_block);
 236                                         DBG((dbg, LEVEL_1, "      arg has same reg: pin %+F(%s)\n", arg, get_reg(arg)->name));
 237                                 } else {
 238                                         /*
 239                                          * First check if there is a phi
 240                                          * - in the same block
 241                                          * - having arg at the current pos in its arg-list
 242                                          * - having the same color as arg
 243                                          *
 244                                          * If found, then pin the arg
 245                                          */
 246                                         DBG((dbg, LEVEL_1, "    they do not interfere\n"));
 247                                         assert(is_Proj(arg));
 248                                         if (!is_pinned(arg)) {
 249                                                 ir_node *other_phi;
 250                                                 DBG((dbg, LEVEL_1, "      searching for phi with same arg having args register\n"));
 251                                                 for(other_phi = get_irn_link(phi_block); other_phi; other_phi = get_irn_link(other_phi)) {
 252                                                         assert(is_Phi(other_phi) && get_nodes_block(phi) == get_nodes_block(other_phi) && "link fields are screwed up");
 253                                                         if (get_irn_n(other_phi, i) == arg && get_reg(other_phi) == arg_reg) {
 254                                                                 DBG((dbg, LEVEL_1, "        found %+F(%s)\n", other_phi, get_reg(other_phi)->name));
 255                                                                 pin_irn(arg, phi_block);
 256                                                                 break;
 257                                                         }
 258                                                 }
 259                                         }
 260
 261                                         if (is_pinned(arg)) {
 262                                                 /* Insert a duplicate of the original value in arguments block,
 263                                                  * make it the new phi arg,
 264                                                  * set its register,
 265                                                  * insert it into schedule,
 266                                                  * pin it
 267                                                  */
 268                                                 ir_node *perm = get_Proj_pred(arg);
 269                                                 ir_node *orig_val = get_irn_n(perm, get_Proj_proj(arg));
 270                                                 ir_node *dupl = new_Copy(chordal_env->main_env->node_factory, cls, chordal_env->irg, arg_block, orig_val);
 271                                                 assert(get_irn_mode(phi) == get_irn_mode(dupl));
 272                                                 set_irn_n(phi, i, dupl);
 273                                                 set_reg(dupl, phi_reg);
 274                                                 sched_add_before(perm, dupl);
 275                                                 pin_irn(dupl, phi_block);
 276                                                 DBG((dbg, LEVEL_1, "      arg is pinned: insert %+F(%s)\n", dupl, get_reg(dupl)->name));
 277                                         } else {
 278                                                 /* No other phi has the same color (else arg would have been pinned),
 279                                                  * so just set the register and pin
 280                                                  */
 281                                                 set_reg(arg, phi_reg);
 282                                                 pin_irn(arg, phi_block);
 283                                                 DBG((dbg, LEVEL_1, "      arg is not pinned: so pin %+F(%s)\n", arg, get_reg(arg)->name));
 284                                         }
 285                                 }
 286                         }
 287                 }
 288         }
 289 }
 290
 291 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
 292         pmap *perm_map = pmap_create();
 293         ir_graph *irg = chordal_env->irg;
 294
 295         dbg = firm_dbg_register("ir.be.ssadestr");
 296
 297         /* create a map for fast lookup of perms: block --> perm */
 298         chordal_env->data = perm_map;
 299         irg_walk_graph(irg, clear_link, collect_phis_walker, chordal_env);
 300
 301         DBG((dbg, LEVEL_1, "Placing perms...\n"));
 302         irg_block_walk_graph(irg, insert_all_perms_walker, NULL, chordal_env);
 303 #ifdef DUMP_GRAPHS
 304         dump_ir_block_graph_sched(irg, "-ssa_destr_perms_placed");
 305 #endif
 306
 307         DBG((dbg, LEVEL_1, "Setting regs and placing dupls...\n"));
 308         irg_block_walk_graph(irg, set_regs_or_place_dupls_walker, NULL, chordal_env);
 309 #ifdef DUMP_GRAPHS
 310         dump_ir_block_graph_sched(irg, "-ssa_destr_regs_set");
 311 #endif
 312
 313         pmap_destroy(perm_map);
 314 }
 315
 316 static void ssa_destruction_check_walker(ir_node *bl, void *data) {
 317         be_chordal_env_t *chordal_env = data;
 318         ir_node *phi;
 319         int i, max;
 320
 321         for(phi = get_irn_link(bl); phi; phi = get_irn_link(phi)) {
 322                 const arch_register_t *phi_reg, *arg_reg;
 323
 324                 phi_reg = get_reg(phi);
 325                 /* iterate over all args of phi */
 326                 for(i=0, max=get_irn_arity(phi); i<max; ++i) {
 327                         ir_node *arg = get_irn_n(phi, i);
 328                         arg_reg = get_reg(arg);
 329                         if(phi_reg != arg_reg) {
 330                                 DBG((dbg, 0, "Error: Registers of %+F and %+F differ: %s %s\n", phi, arg, phi_reg->name, arg_reg->name));
 331                                 assert(0);
 332                         }
 333                         if(!is_pinned(arg)) {
 334                                 DBG((dbg, 0, "Warning: Phi argument %+F is not pinned.\n", arg));
 335                                 assert(0);
 336                         }
 337                 }
 338         }
 339 }
 340
 341 void be_ssa_destruction_check(be_chordal_env_t *chordal_env) {
 342         irg_block_walk_graph(chordal_env->irg, ssa_destruction_check_walker, NULL, chordal_env);
 343 }