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

   1 /*
   2  * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief       Code instrumentation and execution count profiling.
  23  * @author      Adam M. Szalkowski
  24  * @date        06.04.2006
  25  * @version     $Id$
  26  */
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <math.h>
  32
  33 #include "hashptr.h"
  34 #include "debug.h"
  35 #include "obst.h"
  36 #include "set.h"
  37 #include "list.h"
  38 #include "pmap.h"
  39
  40 #include "irprintf.h"
  41 #include "irgwalk.h"
  42 #include "irdump_t.h"
  43 #include "irnode_t.h"
  44 #include "ircons_t.h"
  45 #include "irloop_t.h"
  46 #include "iredges.h"
  47 #include "execfreq.h"
  48 #include "irvrfy.h"
  49 #include "typerep.h"
  50
  51 #include "be_t.h"
  52 #include "belive_t.h"
  53 #include "besched_t.h"
  54 #include "beirgmod.h"
  55 #include "bearch_t.h"
  56 #include "beabi.h"
  57 #include "benode_t.h"
  58 #include "beutil.h"
  59 #include "ircons.h"
  60 #include "irhooks.h"
  61 #include "iredges.h"
  62
  63 #include "bechordal_t.h"
  64
  65 #include "beprofile.h"
  66
  67 /** An entry in the id-to-location map */
  68 typedef struct loc_entry {
  69         ir_entity    *fname;   /**< the entity holding the file name */
  70         unsigned int lineno;   /**< line number */
  71 } loc_entry;
  72
  73 typedef struct _block_id_walker_data_t {
  74         tarval         **array;    /**< the entity the holds the block counts */
  75         unsigned int   id;         /**< current block id number */
  76         ir_node        *symconst;  /**< the SymConst representing array */
  77         pmap           *fname_map; /**< set containing all found filenames */
  78         loc_entry      *locs;      /**< locations */
  79         ir_type        *tp_char;   /**< the character type */
  80         unsigned       flags;      /**< profile flags */
  81 } block_id_walker_data_t;
  82
  83 typedef struct _execcount_t {
  84         unsigned int block;
  85         unsigned int count;
  86 } execcount_t;
  87
  88 static int
  89 cmp_execcount(const void * a, const void * b, size_t size)
  90 {
  91         return ((execcount_t*)a)->block != ((execcount_t*)b)->block;
  92 }
  93
  94 static void
  95 block_counter(ir_node * bb, void * data)
  96 {
  97         unsigned int  *count = data;
  98         *count = *count + 1;
  99 }
 100
 101 static unsigned int
 102 count_blocks(ir_graph * irg)
 103 {
 104         unsigned int count = 0;
 105
 106         irg_block_walk_graph(irg, block_counter, NULL, &count);
 107         return count;
 108 }
 109
 110 /* keep the execcounts here because they are only read once per compiler run */
 111 static set * profile = NULL;
 112 static hook_entry_t hook;
 113
 114 /**
 115  * Instrument a block with code needed for profiling
 116  */
 117 static void
 118 instrument_block(ir_node * bb, ir_node * address, unsigned int id)
 119 {
 120         ir_graph *irg = get_irn_irg(bb);
 121         ir_node  *start_block = get_irg_start_block(irg);
 122         ir_node  *load, *store, *offset, *add, *projm, *proji, *unknown;
 123         ir_node  *cnst;
 124
 125         /**
 126          * We can't instrument the start and end block as there are no real
 127          * instructions in these blocks
 128          */
 129         if(bb == start_block || bb == get_irg_end_block(irg))
 130                 return;
 131
 132         unknown = new_r_Unknown(irg, mode_M);
 133         cnst    = new_r_Const_long(irg, start_block, mode_Iu, get_mode_size_bytes(mode_Iu) * id);
 134         offset  = new_r_Add(irg, bb, address, cnst, mode_P);
 135         load    = new_r_Load(irg, bb, unknown, offset, mode_Iu);
 136         projm   = new_r_Proj(irg, bb, load, mode_M, pn_Load_M);
 137         proji   = new_r_Proj(irg, bb, load, mode_Iu, pn_Load_res);
 138         cnst    = new_r_Const_long(irg, start_block, mode_Iu, 1);
 139         add     = new_r_Add(irg, bb, proji, cnst, mode_Iu);
 140         store   = new_r_Store(irg, bb, projm, offset, add);
 141         projm   = new_r_Proj(irg, bb, store, mode_M, pn_Store_M);
 142         set_irn_link(bb, projm);
 143         set_irn_link(projm, load);
 144 }
 145
 146 typedef struct fix_env {
 147         ir_node *start_block;
 148         ir_node *end_block;
 149 } fix_env;
 150
 151 /**
 152  * SSA Construction for instrumentation code memory
 153  */
 154 static void
 155 fix_ssa(ir_node * bb, void * data)
 156 {
 157         fix_env *env = data;
 158         ir_node *mem;
 159         int     arity = get_Block_n_cfgpreds(bb);
 160
 161         /* start and end block are not instrumented, skip! */
 162         if (bb == env->start_block || bb == env->end_block)
 163                 return;
 164
 165         if (arity == 1) {
 166                 mem = get_irn_link(get_Block_cfgpred_block(bb, 0));
 167         } else {
 168                 int n;
 169                 ir_node **ins;
 170                 ir_graph *irg = current_ir_graph;
 171
 172                 NEW_ARR_A(ir_node*, ins, arity);
 173                 for (n = arity - 1; n >= 0; --n) {
 174                         ins[n] = get_irn_link(get_Block_cfgpred_block(bb, n));
 175                 }
 176                 mem = new_r_Phi(irg, bb, arity, ins, mode_M);
 177         }
 178         set_Load_mem(get_irn_link(get_irn_link(bb)), mem);
 179 }
 180
 181
 182 /**
 183  * Generates a new irg which calls the initializer
 184  *
 185  * Pseudocode:
 186  *       void __firmprof_initializer(void) { __init_firmprof(ent_filename, bblock_id, bblock_counts, n_blocks); }
 187  */
 188 static ir_graph *
 189 gen_initializer_irg(ir_entity * ent_filename, ir_entity * bblock_id, ir_entity * bblock_counts, int n_blocks)
 190 {
 191         ir_node *start_block;
 192
 193         ir_node   *ins[4];
 194         ident     *name = new_id_from_str("__firmprof_initializer");
 195         ir_entity *ent  = new_entity(get_glob_type(), name, new_type_method(name, 0, 0));
 196         ir_node   *ret, *call, *symconst;
 197         symconst_symbol sym;
 198
 199         ident     *init_name = new_id_from_str("__init_firmprof");
 200         ir_type   *init_type = new_type_method(init_name, 4, 0);
 201         ir_type   *uint, *uintptr, *string;
 202         ir_entity *init_ent;
 203         ir_graph  *irg;
 204         ir_node   *bb;
 205         ir_type   *empty_frame_type;
 206
 207         set_entity_ld_ident(ent, name);
 208
 209         uint    = new_type_primitive(new_id_from_str("__uint"), mode_Iu);
 210         uintptr = new_type_pointer(new_id_from_str("__uintptr"), uint, mode_P);
 211         string  = new_type_pointer(new_id_from_str("__charptr"), new_type_primitive(new_id_from_str("__char"), mode_Bs), mode_P);
 212
 213         set_method_param_type(init_type, 0, string);
 214         set_method_param_type(init_type, 1, uintptr);
 215         set_method_param_type(init_type, 2, uintptr);
 216         set_method_param_type(init_type, 3, uint);
 217         init_ent = new_entity(get_glob_type(), init_name, init_type);
 218         set_entity_ld_ident(init_ent, init_name);
 219
 220         irg = new_ir_graph(ent, 0);
 221         empty_frame_type = get_irg_frame_type(irg);
 222         set_type_size_bytes(empty_frame_type, 0);
 223
 224         bb = get_cur_block();
 225
 226         start_block = get_irg_start_block(irg);
 227
 228         sym.entity_p = init_ent;
 229         symconst     = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 230
 231         sym.entity_p = ent_filename;
 232         ins[0] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 233         sym.entity_p = bblock_id;
 234         ins[1] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 235         sym.entity_p = bblock_counts;
 236         ins[2] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 237         ins[3] = new_r_Const_long(irg, start_block, mode_Iu, n_blocks);
 238
 239         call = new_r_Call(irg, bb, get_irg_initial_mem(irg), symconst, 4, ins, init_type);
 240         ret = new_r_Return(irg, bb, new_r_Proj(irg, bb, call, mode_M, pn_Call_M_regular), 0, NULL);
 241         mature_immBlock(bb);
 242
 243         add_immBlock_pred(get_irg_end_block(irg), ret);
 244         mature_immBlock(get_irg_end_block(irg));
 245
 246         irg_finalize_cons(irg);
 247
 248         return irg;
 249 }
 250
 251 /**
 252  * Create the location data for the given debug info.
 253  */
 254 static void create_location_data(dbg_info *dbg, block_id_walker_data_t *wd)
 255 {
 256         unsigned lineno;
 257         const char *fname = be_retrieve_dbg_info(dbg, &lineno);
 258
 259         if (fname) {
 260                 pmap_entry *entry = pmap_find(wd->fname_map, (void *)fname);
 261                 ir_entity  *ent;
 262
 263                 if (! entry) {
 264                         static unsigned nr = 0;
 265                         ident   *id;
 266                         char    buf[128];
 267                         ir_type *arr;
 268                         int     i, len = strlen(fname) + 1;
 269                         tarval  **tarval_string;
 270
 271                         snprintf(buf, sizeof(buf), "firm_name_arr.%d", nr);
 272                         arr = new_type_array(new_id_from_str(buf), 1, wd->tp_char);
 273                         set_array_bounds_int(arr, 0, 0, len);
 274
 275                         snprintf(buf, sizeof(buf), "__firm_name.%d", nr++);
 276                         id = new_id_from_str(buf);
 277                         ent = new_entity(get_glob_type(), id, arr);
 278                         set_entity_ld_ident(ent, id);
 279
 280                         pmap_insert(wd->fname_map, (void *)fname, ent);
 281
 282                         /* initialize file name string constant */
 283                         tarval_string = alloca(sizeof(*tarval_string) * (len));
 284                         for (i = 0; i < len; ++i) {
 285                                 tarval_string[i] = new_tarval_from_long(fname[i], mode_Bs);
 286                         }
 287                         set_entity_variability(ent, variability_constant);
 288                         set_array_entity_values(ent, tarval_string, len);
 289                 } else {
 290                         ent = entry->value;
 291                 }
 292                 wd->locs[wd->id].fname  = ent;
 293                 wd->locs[wd->id].lineno = lineno;
 294         } else {
 295                 wd->locs[wd->id].fname  = NULL;
 296                 wd->locs[wd->id].lineno = 0;
 297         }
 298 }
 299
 300 /**
 301  * Walker: assigns an ID to every block.
 302  * Builds the string table
 303  */
 304 static void
 305 block_id_walker(ir_node * bb, void * data)
 306 {
 307         block_id_walker_data_t *wd = data;
 308
 309         wd->array[wd->id] = new_tarval_from_long(get_irn_node_nr(bb), mode_Iu);
 310         instrument_block(bb, wd->symconst, wd->id);
 311
 312         if (wd->flags & profile_with_locations) {
 313                 dbg_info *dbg = get_irn_dbg_info(bb);
 314                 create_location_data(dbg, wd);
 315         }
 316         ++wd->id;
 317 }
 318
 319 #define IDENT(x)        new_id_from_chars(x, sizeof(x) - 1)
 320
 321 ir_graph *
 322 be_profile_instrument(const char *filename, unsigned flags)
 323 {
 324         int n, i;
 325         int n_blocks = 0;
 326         ir_entity *bblock_id;
 327         ir_entity *bblock_counts;
 328         ir_entity *ent_filename;
 329         ir_entity *ent_locations = NULL;
 330         ir_entity *loc_lineno = NULL;
 331         ir_entity *loc_name = NULL;
 332         ir_entity *ent;
 333         ir_type *array_type;
 334         ir_type *uint_type;
 335         ir_type *string_type;
 336         ir_type *character_type;
 337         ir_type *loc_type = NULL;
 338         ir_type *charptr_type;
 339         ir_type *gtp;
 340         tarval **tarval_array;
 341         tarval **tarval_string;
 342         tarval *tv;
 343         int filename_len = strlen(filename)+1;
 344         ident *cur_ident;
 345         int align_l, align_n, size;
 346         ir_graph *rem;
 347         block_id_walker_data_t  wd;
 348         symconst_symbol sym;
 349
 350         /* count the number of block first */
 351         for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
 352                 ir_graph *irg = get_irp_irg(n);
 353
 354                 n_blocks += count_blocks(irg);
 355         }
 356
 357         /* create all the necessary types and entities. Note that the
 358            types must have a fixed layout, because we already running in the
 359            backend */
 360         uint_type      = new_type_primitive(IDENT("__uint"), mode_Iu);
 361         set_type_alignment_bytes(uint_type, get_type_size_bytes(uint_type));
 362         array_type     = new_type_array(IDENT("__block_info_array"), 1, uint_type);
 363         set_array_bounds_int(array_type, 0, 0, n_blocks);
 364
 365         character_type = new_type_primitive(IDENT("__char"), mode_Bs);
 366         string_type    = new_type_array(IDENT("__filename"), 1, character_type);
 367         set_array_bounds_int(string_type, 0, 0, filename_len);
 368
 369         gtp            = get_glob_type();
 370
 371         cur_ident      = IDENT("__FIRMPROF__BLOCK_IDS");
 372         bblock_id      = new_entity(gtp, cur_ident, array_type);
 373         set_entity_ld_ident(bblock_id, cur_ident);
 374         set_entity_variability(bblock_id, variability_initialized);
 375
 376         cur_ident      = IDENT("__FIRMPROF__BLOCK_COUNTS");
 377         bblock_counts  = new_entity(gtp, cur_ident, array_type);
 378         set_entity_ld_ident(bblock_counts, cur_ident);
 379         set_entity_variability(bblock_counts, variability_initialized);
 380
 381         cur_ident      = IDENT("__FIRMPROF__FILE_NAME");
 382         ent_filename   = new_entity(gtp, cur_ident, string_type);
 383         set_entity_ld_ident(ent_filename, cur_ident);
 384
 385         if (flags & profile_with_locations) {
 386                 loc_type       = new_type_struct(IDENT("__location"));
 387                 loc_lineno     = new_entity(loc_type, IDENT("lineno"), uint_type);
 388                 align_l        = get_type_alignment_bytes(uint_type);
 389                 size           = get_type_size_bytes(uint_type);
 390                 set_entity_offset(loc_lineno, 0);
 391
 392                 charptr_type   = new_type_pointer(IDENT("__charptr"), character_type, mode_P_data);
 393                 align_n        = get_type_size_bytes(charptr_type);
 394                 set_type_alignment_bytes(charptr_type, align_n);
 395                 loc_name       = new_entity(loc_type, IDENT("name"), charptr_type);
 396                 size           = (size + align_n - 1) & -align_n;
 397                 set_entity_offset(loc_name, size);
 398                 size          += align_n;
 399
 400                 if (align_n > align_l)
 401                         align_l = align_n;
 402                 size = (size + align_l - 1) & -align_l;
 403                 set_type_size_bytes(loc_type, size);
 404                 set_type_state(loc_type, layout_fixed);
 405
 406                 loc_type = new_type_array(IDENT("__locarray"), 1, loc_type);
 407                 set_array_bounds_int(string_type, 0, 0, n_blocks);
 408
 409                 cur_ident      = IDENT("__FIRMPROF__LOCATIONS");
 410                 ent_locations   = new_entity(gtp, cur_ident, loc_type);
 411                 set_entity_ld_ident(ent_locations, cur_ident);
 412         }
 413
 414         /* initialize count array */
 415         NEW_ARR_A(tarval *, tarval_array, n_blocks);
 416         tv = get_tarval_null(mode_Iu);
 417         for (i = 0; i < n_blocks; ++i) {
 418                 tarval_array[i] = tv;
 419         }
 420         set_array_entity_values(bblock_counts, tarval_array, n_blocks);
 421
 422         /* initialize function name string constant */
 423         tarval_string = alloca(sizeof(*tarval_string) * (filename_len));
 424         for (i = 0; i < filename_len; ++i) {
 425                 tarval_string[i] = new_tarval_from_long(filename[i], mode_Bs);
 426         }
 427         set_entity_variability(ent_filename, variability_constant);
 428         set_array_entity_values(ent_filename, tarval_string, filename_len);
 429
 430         /* initialize block id array and instrument blocks */
 431         wd.array     = tarval_array;
 432         wd.id        = 0;
 433         wd.tp_char   = character_type;
 434         wd.flags     = flags;
 435         if (flags & profile_with_locations) {
 436                 wd.fname_map = pmap_create();
 437                 NEW_ARR_A(loc_entry, wd.locs, n_blocks);
 438         }
 439
 440         for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
 441                 ir_graph      *irg = get_irp_irg(n);
 442                 int            i;
 443                 ir_node       *endbb = get_irg_end_block(irg);
 444                 fix_env       env;
 445
 446                 set_current_ir_graph(irg);
 447
 448                 /* generate a symbolic constant pointing to the count array */
 449                 sym.entity_p = bblock_counts;
 450                 wd.symconst  = new_r_SymConst(irg, get_irg_start_block(irg), sym, symconst_addr_ent);
 451
 452                 irg_block_walk_graph(irg, block_id_walker, NULL, &wd);
 453                 env.start_block = get_irg_start_block(irg);
 454                 env.end_block   = get_irg_end_block(irg);
 455                 set_irn_link(env.start_block, get_irg_no_mem(irg));
 456                 irg_block_walk_graph(irg, fix_ssa, NULL, &env);
 457                 for (i = get_Block_n_cfgpreds(endbb) - 1; i >= 0; --i) {
 458                         ir_node *node = skip_Proj(get_Block_cfgpred(endbb, i));
 459                         ir_node *bb   = get_Block_cfgpred_block(endbb, i);
 460                         ir_node *sync;
 461                         ir_node *ins[2];
 462
 463                         switch (get_irn_opcode(node)) {
 464                         case iro_Return:
 465                                 ins[0] = get_irn_link(bb);
 466                                 ins[1] = get_Return_mem(node);
 467                                 sync   = new_r_Sync(irg, bb, 2, ins);
 468                                 set_Return_mem(node, sync);
 469                                 break;
 470                         case iro_Raise:
 471                                 ins[0] = get_irn_link(bb);
 472                                 ins[1] = get_Raise_mem(node);
 473                                 sync   = new_r_Sync(irg, bb, 2, ins);
 474                                 set_Raise_mem(node, sync);
 475                                 break;
 476                         default:
 477                                 /* a fragile's op exception. There should be another path to End,
 478                                    so ignore it */
 479                                 assert(is_fragile_op(node) && "unexpected End control flow predecessor");
 480                         }
 481                 }
 482         }
 483         set_array_entity_values(bblock_id, tarval_array, n_blocks);
 484
 485         if (flags & profile_with_locations) {
 486                 /* build the initializer for the locations */
 487                 rem = current_ir_graph;
 488                 current_ir_graph = get_const_code_irg();
 489                 ent = get_array_element_entity(loc_type);
 490                 set_entity_variability(ent_locations, variability_constant);
 491                 for (i = 0; i < n_blocks; ++i) {
 492                         compound_graph_path *path;
 493                         tarval *tv;
 494                         ir_node *n;
 495
 496                         /* lineno */
 497                         path = new_compound_graph_path(loc_type, 2);
 498                         set_compound_graph_path_array_index(path, 0, i);
 499                         set_compound_graph_path_node(path, 0, ent);
 500                         set_compound_graph_path_node(path, 1, loc_lineno);
 501                         tv = new_tarval_from_long(wd.locs[i].lineno, mode_Iu);
 502                         add_compound_ent_value_w_path(ent_locations, new_Const(mode_Iu, tv), path);
 503
 504                         /* name */
 505                         path = new_compound_graph_path(loc_type, 2);
 506                         set_compound_graph_path_array_index(path, 0, i);
 507                         set_compound_graph_path_node(path, 0, ent);
 508                         set_compound_graph_path_node(path, 1, loc_name);
 509                         if (wd.locs[i].fname) {
 510                                 sym.entity_p = wd.locs[i].fname;
 511                                 n = new_SymConst(sym, symconst_addr_ent);
 512                         } else {
 513                                 n = new_Const(mode_P_data, get_mode_null(mode_P_data));
 514                         }
 515                         add_compound_ent_value_w_path(ent_locations, n, path);
 516                 }
 517                 pmap_destroy(wd.fname_map);
 518         }
 519         return gen_initializer_irg(ent_filename, bblock_id, bblock_counts, n_blocks);
 520 }
 521
 522 static void
 523 profile_node_info(void *ctx, FILE *f, const ir_node *irn)
 524 {
 525         if(is_Block(irn)) {
 526                 fprintf(f, "profiled execution count: %u\n", be_profile_get_block_execcount(irn));
 527         }
 528 }
 529
 530 static void
 531 register_vcg_hook(void)
 532 {
 533         memset(&hook, 0, sizeof(hook));
 534         hook.hook._hook_node_info = profile_node_info;
 535         register_hook(hook_node_info, &hook);
 536 }
 537
 538 static void
 539 unregister_vcg_hook(void)
 540 {
 541         unregister_hook(hook_node_info, &hook);
 542 }
 543
 544 /**
 545  * Reads the corresponding profile info file if it exists and returns a
 546  * profile info struct
 547  */
 548 void
 549 be_profile_read(const char *filename)
 550 {
 551         FILE   *f;
 552         char    buf[8];
 553         size_t  ret;
 554
 555         f = fopen(filename, "r");
 556         if(f == NULL) {
 557                 return;
 558         }
 559         printf("found profile data '%s'.\n", filename);
 560
 561         /* check magic */
 562         ret = fread(buf, 8, 1, f);
 563         if(ret == 0 || strncmp(buf, "firmprof", 8) != 0) {
 564                 return;
 565         }
 566
 567         if(profile) be_profile_free();
 568         profile = new_set(cmp_execcount, 16);
 569
 570         do {
 571                 execcount_t  query;
 572                 ret = fread(&query, sizeof(unsigned int), 2, f);
 573
 574                 if(ret != 2) break;
 575
 576                 set_insert(profile, &query, sizeof(query), query.block);
 577         } while(1);
 578
 579         fclose(f);
 580         register_vcg_hook();
 581 }
 582
 583 /**
 584  * Frees the profile info
 585  */
 586 void
 587 be_profile_free(void)
 588 {
 589         if(profile) {
 590                 unregister_vcg_hook();
 591                 del_set(profile);
 592         }
 593 }
 594
 595 /**
 596  * Tells whether profile module has acquired data
 597  */
 598 int
 599 be_profile_has_data(void)
 600 {
 601         return (profile != NULL);
 602 }
 603
 604 /**
 605  * Get block execution count as determined be profiling
 606  */
 607 unsigned int
 608 be_profile_get_block_execcount(const ir_node *block)
 609 {
 610         execcount_t *ec, query;
 611
 612         if(!profile)
 613                 return 1;
 614
 615         query.block = get_irn_node_nr(block);
 616         ec = set_find(profile, &query, sizeof(query), get_irn_node_nr(block));
 617
 618         if(ec != NULL) {
 619                 return ec->count;
 620         } else {
 621                 ir_fprintf(stderr, "Warning: Profile contains no data for %+F\n",
 622                            block);
 623                 return 1;
 624         }
 625 }
 626
 627 typedef struct _intialize_execfreq_env_t {
 628         ir_graph *irg;
 629         ir_exec_freq *execfreqs;
 630         double freq_factor;
 631 } initialize_execfreq_env_t;
 632
 633 // minimal execution frequency (an execfreq of 0 confuses algos)
 634 static const double MIN_EXECFREQ = 0.00001;
 635
 636 static void initialize_execfreq(ir_node *block, void *data) {
 637         initialize_execfreq_env_t *env = data;
 638         double freq;
 639
 640         if(block == get_irg_start_block(env->irg)
 641            || block == get_irg_end_block(env->irg)) {
 642                 freq = 1.0;
 643         } else {
 644                 freq = be_profile_get_block_execcount(block);
 645                 freq *= env->freq_factor;
 646                 if(freq < MIN_EXECFREQ)
 647                         freq = MIN_EXECFREQ;
 648         }
 649
 650         set_execfreq(env->execfreqs, block, freq);
 651 }
 652
 653 ir_exec_freq *be_create_execfreqs_from_profile(ir_graph *irg)
 654 {
 655         ir_node *block2 = NULL;
 656         ir_node *start_block;
 657         const ir_edge_t *edge;
 658         initialize_execfreq_env_t env;
 659         unsigned count;
 660
 661         env.irg = irg;
 662         env.execfreqs = create_execfreq(irg);
 663
 664         // find the successor to the start block
 665         start_block = get_irg_start_block(irg);
 666         foreach_block_succ(start_block, edge) {
 667                 ir_node *succ = get_edge_src_irn(edge);
 668                 if(succ != start_block) {
 669                         block2 = succ;
 670                         break;
 671                 }
 672         }
 673         assert(block2 != NULL);
 674
 675         count = be_profile_get_block_execcount(block2);
 676         if(count == 0) {
 677                 // the function was never executed, so fallback to estimated freqs
 678                 free_execfreq(env.execfreqs);
 679
 680                 return compute_execfreq(irg, 10);
 681         }
 682
 683         env.freq_factor = 1.0 / count;
 684         irg_block_walk_graph(irg, initialize_execfreq, NULL, &env);
 685
 686         return env.execfreqs;
 687 }