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

   1 /** vim: set sw=4 ts=4:
   2  * @file   beprofile.c
   3  * @date   2006-04-06
   4  * @author Adam M. Szalkowski
   5  * @cvs-id $Id$
   6  *
   7  * Code instrumentation and execution count profiling
   8  *
   9  * Copyright (C) 2006 Universitaet Karlsruhe
  10  * Released under the GPL
  11  */
  12 #ifdef HAVE_CONFIG_H
  13 #include "config.h"
  14 #endif
  15
  16 #include <math.h>
  17
  18 #include "hashptr.h"
  19 #include "debug.h"
  20 #include "obst.h"
  21 #include "set.h"
  22 #include "list.h"
  23 #include "pmap.h"
  24
  25 #include "entity.h"
  26 #include "irprintf.h"
  27 #include "irgwalk.h"
  28 #include "irdump_t.h"
  29 #include "irnode_t.h"
  30 #include "ircons_t.h"
  31 #include "irloop_t.h"
  32 #include "iredges.h"
  33 #include "execfreq.h"
  34 #include "irvrfy.h"
  35 #include "type.h"
  36
  37 #include "be_t.h"
  38 #include "belive_t.h"
  39 #include "besched_t.h"
  40 #include "beirgmod.h"
  41 #include "bearch_t.h"
  42 #include "beabi.h"
  43 #include "benode_t.h"
  44 #include "beutil.h"
  45 #include "ircons.h"
  46 #include "irhooks.h"
  47 #include "iredges.h"
  48
  49 #include "bechordal_t.h"
  50
  51 #include "beprofile.h"
  52
  53 /** An entry in the id-to-location map */
  54 typedef struct loc_entry {
  55         ir_entity    *fname;   /**< the entity holding the file name */
  56         unsigned int lineno;   /**< line number */
  57 } loc_entry;
  58
  59 typedef struct _block_id_walker_data_t {
  60         tarval         **array;    /**< the entity the holds the block counts */
  61         unsigned int   id;         /**< current block id number */
  62         ir_node        *symconst;  /**< the SymConst representing array */
  63         pmap           *fname_map; /**< set containing all found filenames */
  64         loc_entry      *locs;      /**< locations */
  65         ir_type        *tp_char;   /**< the character type */
  66         unsigned       flags;      /**< profile flags */
  67 } block_id_walker_data_t;
  68
  69 typedef struct _execcount_t {
  70         unsigned int block;
  71         unsigned int count;
  72 } execcount_t;
  73
  74 static int
  75 cmp_execcount(const void * a, const void * b, size_t size)
  76 {
  77         return ((execcount_t*)a)->block != ((execcount_t*)b)->block;
  78 }
  79
  80 static void
  81 block_counter(ir_node * bb, void * data)
  82 {
  83         unsigned int  *count = data;
  84         *count = *count + 1;
  85 }
  86
  87 static unsigned int
  88 count_blocks(ir_graph * irg)
  89 {
  90         unsigned int count = 0;
  91
  92         irg_block_walk_graph(irg, block_counter, NULL, &count);
  93         return count;
  94 }
  95
  96 /* keep the execcounts here because they are only read once per compiler run */
  97 static set * profile = NULL;
  98 static hook_entry_t hook;
  99
 100 /**
 101  * Instrument a block with code needed for profiling
 102  */
 103 static void
 104 instrument_block(ir_node * bb, ir_node * address, unsigned int id)
 105 {
 106         ir_graph *irg = get_irn_irg(bb);
 107         ir_node  *start_block = get_irg_start_block(irg);
 108         ir_node  *load, *store, *offset, *add, *projm, *proji, *unknown;
 109         ir_node  *cnst;
 110
 111         /**
 112          * We can't instrument the start and end block as there are no real
 113          * instructions in these blocks
 114          */
 115         if(bb == start_block || bb == get_irg_end_block(irg))
 116                 return;
 117
 118         unknown = new_r_Unknown(irg, mode_M);
 119         cnst    = new_r_Const_long(irg, start_block, mode_Iu, get_mode_size_bytes(mode_Iu) * id);
 120         offset  = new_r_Add(irg, bb, address, cnst, mode_P);
 121         load    = new_r_Load(irg, bb, unknown, offset, mode_Iu);
 122         projm   = new_r_Proj(irg, bb, load, mode_M, pn_Load_M);
 123         proji   = new_r_Proj(irg, bb, load, mode_Iu, pn_Load_res);
 124         cnst    = new_r_Const_long(irg, start_block, mode_Iu, 1);
 125         add     = new_r_Add(irg, bb, proji, cnst, mode_Iu);
 126         store   = new_r_Store(irg, bb, projm, offset, add);
 127         projm   = new_r_Proj(irg, bb, store, mode_M, pn_Store_M);
 128         set_irn_link(bb, projm);
 129         set_irn_link(projm, load);
 130 }
 131
 132 typedef struct fix_env {
 133         ir_node *start_block;
 134         ir_node *end_block;
 135 } fix_env;
 136
 137 /**
 138  * SSA Construction for instrumentation code memory
 139  */
 140 static void
 141 fix_ssa(ir_node * bb, void * data)
 142 {
 143         fix_env *env = data;
 144         ir_node *mem;
 145         int     arity = get_Block_n_cfgpreds(bb);
 146
 147         /* start and end block are not instrumented, skip! */
 148         if (bb == env->start_block || bb == env->end_block)
 149                 return;
 150
 151         if (arity == 1) {
 152                 mem = get_irn_link(get_Block_cfgpred_block(bb, 0));
 153         } else {
 154                 int n;
 155                 ir_node **ins;
 156                 ir_graph *irg = current_ir_graph;
 157
 158                 NEW_ARR_A(ir_node*, ins, arity);
 159                 for (n = arity - 1; n >= 0; --n) {
 160                         ins[n] = get_irn_link(get_Block_cfgpred_block(bb, n));
 161                 }
 162                 mem = new_r_Phi(irg, bb, arity, ins, mode_M);
 163         }
 164         set_Load_mem(get_irn_link(get_irn_link(bb)), mem);
 165 }
 166
 167
 168 /**
 169  * Generates a new irg which calls the initializer
 170  *
 171  * Pseudocode:
 172  *       void __firmprof_initializer(void) { __init_firmprof(ent_filename, bblock_id, bblock_counts, n_blocks); }
 173  */
 174 static ir_graph *
 175 gen_initializer_irg(ir_entity * ent_filename, ir_entity * bblock_id, ir_entity * bblock_counts, int n_blocks)
 176 {
 177         ir_node *start_block;
 178
 179         ir_node   *ins[4];
 180         ident     *name = new_id_from_str("__firmprof_initializer");
 181         ir_entity *ent  = new_entity(get_glob_type(), name, new_type_method(name, 0, 0));
 182         ir_node   *ret, *call, *symconst;
 183         symconst_symbol sym;
 184
 185         ident     *init_name = new_id_from_str("__init_firmprof");
 186         ir_type   *init_type = new_type_method(init_name, 4, 0);
 187         ir_type   *uint, *uintptr, *string;
 188         ir_entity *init_ent;
 189         ir_graph  *irg;
 190         ir_node   *bb;
 191         ir_type   *empty_frame_type;
 192
 193         set_entity_ld_ident(ent, name);
 194
 195         uint    = new_type_primitive(new_id_from_str("__uint"), mode_Iu);
 196         uintptr = new_type_pointer(new_id_from_str("__uintptr"), uint, mode_P);
 197         string  = new_type_pointer(new_id_from_str("__charptr"), new_type_primitive(new_id_from_str("__char"), mode_Bs), mode_P);
 198
 199         set_method_param_type(init_type, 0, string);
 200         set_method_param_type(init_type, 1, uintptr);
 201         set_method_param_type(init_type, 2, uintptr);
 202         set_method_param_type(init_type, 3, uint);
 203         init_ent = new_entity(get_glob_type(), init_name, init_type);
 204         set_entity_ld_ident(init_ent, init_name);
 205
 206         irg = new_ir_graph(ent, 0);
 207         empty_frame_type = get_irg_frame_type(irg);
 208         set_type_size_bytes(empty_frame_type, 0);
 209
 210         bb = get_cur_block();
 211
 212         start_block = get_irg_start_block(irg);
 213
 214         sym.entity_p = init_ent;
 215         symconst     = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 216
 217         sym.entity_p = ent_filename;
 218         ins[0] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 219         sym.entity_p = bblock_id;
 220         ins[1] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 221         sym.entity_p = bblock_counts;
 222         ins[2] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 223         ins[3] = new_r_Const_long(irg, start_block, mode_Iu, n_blocks);
 224
 225         call = new_r_Call(irg, bb, get_irg_initial_mem(irg), symconst, 4, ins, init_type);
 226         ret = new_r_Return(irg, bb, new_r_Proj(irg, bb, call, mode_M, pn_Call_M_regular), 0, NULL);
 227         mature_immBlock(bb);
 228
 229         add_immBlock_pred(get_irg_end_block(irg), ret);
 230         mature_immBlock(get_irg_end_block(irg));
 231
 232         irg_finalize_cons(irg);
 233
 234         return irg;
 235 }
 236
 237 /**
 238  * Create the location data for the given debug info.
 239  */
 240 static void create_location_data(dbg_info *dbg, block_id_walker_data_t *wd)
 241 {
 242         unsigned lineno;
 243         const char *fname = be_retrieve_dbg_info(dbg, &lineno);
 244
 245         if (fname) {
 246                 pmap_entry *entry = pmap_find(wd->fname_map, (void *)fname);
 247                 ir_entity  *ent;
 248
 249                 if (! entry) {
 250                         static unsigned nr = 0;
 251                         ident   *id;
 252                         char    buf[128];
 253                         ir_type *arr;
 254                         int     i, len = strlen(fname) + 1;
 255                         tarval  **tarval_string;
 256
 257                         snprintf(buf, sizeof(buf), "firm_name_arr.%d", nr);
 258                         arr = new_type_array(new_id_from_str(buf), 1, wd->tp_char);
 259                         set_array_bounds_int(arr, 0, 0, len);
 260
 261                         snprintf(buf, sizeof(buf), "__firm_name.%d", nr++);
 262                         id = new_id_from_str(buf);
 263                         ent = new_entity(get_glob_type(), id, arr);
 264                         set_entity_ld_ident(ent, id);
 265
 266                         pmap_insert(wd->fname_map, (void *)fname, ent);
 267
 268                         /* initialize file name string constant */
 269                         tarval_string = alloca(sizeof(*tarval_string) * (len));
 270                         for (i = 0; i < len; ++i) {
 271                                 tarval_string[i] = new_tarval_from_long(fname[i], mode_Bs);
 272                         }
 273                         set_entity_variability(ent, variability_constant);
 274                         set_array_entity_values(ent, tarval_string, len);
 275                 } else {
 276                         ent = entry->value;
 277                 }
 278                 wd->locs[wd->id].fname  = ent;
 279                 wd->locs[wd->id].lineno = lineno;
 280         } else {
 281                 wd->locs[wd->id].fname  = NULL;
 282                 wd->locs[wd->id].lineno = 0;
 283         }
 284 }
 285
 286 /**
 287  * Walker: assigns an ID to every block.
 288  * Builds the string table
 289  */
 290 static void
 291 block_id_walker(ir_node * bb, void * data)
 292 {
 293         block_id_walker_data_t *wd = data;
 294
 295         wd->array[wd->id] = new_tarval_from_long(get_irn_node_nr(bb), mode_Iu);
 296         instrument_block(bb, wd->symconst, wd->id);
 297
 298         if (wd->flags & profile_with_locations) {
 299                 dbg_info *dbg = get_irn_dbg_info(bb);
 300                 create_location_data(dbg, wd);
 301         }
 302         ++wd->id;
 303 }
 304
 305 #define IDENT(x)        new_id_from_chars(x, sizeof(x) - 1)
 306
 307 ir_graph *
 308 be_profile_instrument(const char *filename, unsigned flags)
 309 {
 310         int n, i;
 311         unsigned int n_blocks = 0;
 312         ir_entity *bblock_id;
 313         ir_entity *bblock_counts;
 314         ir_entity *ent_filename;
 315         ir_entity *ent_locations = NULL;
 316         ir_entity *loc_lineno = NULL;
 317         ir_entity *loc_name = NULL;
 318         ir_entity *ent;
 319         ir_type *array_type;
 320         ir_type *uint_type;
 321         ir_type *string_type;
 322         ir_type *character_type;
 323         ir_type *loc_type = NULL;
 324         ir_type *charptr_type;
 325         ir_type *gtp;
 326         tarval **tarval_array;
 327         tarval **tarval_string;
 328         tarval *tv;
 329         int filename_len = strlen(filename)+1;
 330         ident *cur_ident;
 331         int align_l, align_n, size;
 332         ir_graph *rem;
 333         block_id_walker_data_t  wd;
 334         symconst_symbol sym;
 335
 336         /* count the number of block first */
 337         for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
 338                 ir_graph *irg = get_irp_irg(n);
 339
 340                 n_blocks += count_blocks(irg);
 341         }
 342
 343         /* create all the necessary types and entities. Note that the
 344            types must have a fixed layout, because we already running in the
 345            backend */
 346         uint_type      = new_type_primitive(IDENT("__uint"), mode_Iu);
 347         set_type_alignment_bytes(uint_type, get_type_size_bytes(uint_type));
 348         array_type     = new_type_array(IDENT("__block_info_array"), 1, uint_type);
 349         set_array_bounds_int(array_type, 0, 0, n_blocks);
 350
 351         character_type = new_type_primitive(IDENT("__char"), mode_Bs);
 352         string_type    = new_type_array(IDENT("__filename"), 1, character_type);
 353         set_array_bounds_int(string_type, 0, 0, filename_len);
 354
 355         gtp            = get_glob_type();
 356
 357         cur_ident      = IDENT("__FIRMPROF__BLOCK_IDS");
 358         bblock_id      = new_entity(gtp, cur_ident, array_type);
 359         set_entity_ld_ident(bblock_id, cur_ident);
 360         set_entity_variability(bblock_id, variability_initialized);
 361
 362         cur_ident      = IDENT("__FIRMPROF__BLOCK_COUNTS");
 363         bblock_counts  = new_entity(gtp, cur_ident, array_type);
 364         set_entity_ld_ident(bblock_counts, cur_ident);
 365         set_entity_variability(bblock_counts, variability_initialized);
 366
 367         cur_ident      = IDENT("__FIRMPROF__FILE_NAME");
 368         ent_filename   = new_entity(gtp, cur_ident, string_type);
 369         set_entity_ld_ident(ent_filename, cur_ident);
 370
 371         if (flags & profile_with_locations) {
 372                 loc_type       = new_type_struct(IDENT("__location"));
 373                 loc_lineno     = new_entity(loc_type, IDENT("lineno"), uint_type);
 374                 align_l        = get_type_alignment_bytes(uint_type);
 375                 size           = get_type_size_bytes(uint_type);
 376                 set_entity_offset(loc_lineno, 0);
 377
 378                 charptr_type   = new_type_pointer(IDENT("__charptr"), character_type, mode_P_data);
 379                 align_n        = get_type_size_bytes(charptr_type);
 380                 set_type_alignment_bytes(charptr_type, align_n);
 381                 loc_name       = new_entity(loc_type, IDENT("name"), charptr_type);
 382                 size           = (size + align_n - 1) & -align_n;
 383                 set_entity_offset(loc_name, size);
 384                 size          += align_n;
 385
 386                 if (align_n > align_l)
 387                         align_l = align_n;
 388                 size = (size + align_l - 1) & -align_l;
 389                 set_type_size_bytes(loc_type, size);
 390                 set_type_state(loc_type, layout_fixed);
 391
 392                 loc_type = new_type_array(IDENT("__locarray"), 1, loc_type);
 393                 set_array_bounds_int(string_type, 0, 0, n_blocks);
 394
 395                 cur_ident      = IDENT("__FIRMPROF__LOCATIONS");
 396                 ent_locations   = new_entity(gtp, cur_ident, loc_type);
 397                 set_entity_ld_ident(ent_locations, cur_ident);
 398         }
 399
 400         /* initialize count array */
 401         NEW_ARR_A(tarval *, tarval_array, n_blocks);
 402         tv = get_tarval_null(mode_Iu);
 403         for (i = 0; i < n_blocks; ++i) {
 404                 tarval_array[i] = tv;
 405         }
 406         set_array_entity_values(bblock_counts, tarval_array, n_blocks);
 407
 408         /* initialize function name string constant */
 409         tarval_string = alloca(sizeof(*tarval_string) * (filename_len));
 410         for (i = 0; i < filename_len; ++i) {
 411                 tarval_string[i] = new_tarval_from_long(filename[i], mode_Bs);
 412         }
 413         set_entity_variability(ent_filename, variability_constant);
 414         set_array_entity_values(ent_filename, tarval_string, filename_len);
 415
 416         /* initialize block id array and instrument blocks */
 417         wd.array     = tarval_array;
 418         wd.id        = 0;
 419         wd.tp_char   = character_type;
 420         wd.flags     = flags;
 421         if (flags & profile_with_locations) {
 422                 wd.fname_map = pmap_create();
 423                 NEW_ARR_A(loc_entry, wd.locs, n_blocks);
 424         }
 425
 426         for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
 427                 ir_graph      *irg = get_irp_irg(n);
 428                 int            i;
 429                 ir_node       *endbb = get_irg_end_block(irg);
 430                 fix_env       env;
 431
 432                 set_current_ir_graph(irg);
 433
 434                 /* generate a symbolic constant pointing to the count array */
 435                 sym.entity_p = bblock_counts;
 436                 wd.symconst  = new_r_SymConst(irg, get_irg_start_block(irg), sym, symconst_addr_ent);
 437
 438                 irg_block_walk_graph(irg, block_id_walker, NULL, &wd);
 439                 env.start_block = get_irg_start_block(irg);
 440                 env.end_block   = get_irg_end_block(irg);
 441                 set_irn_link(env.start_block, get_irg_no_mem(irg));
 442                 irg_block_walk_graph(irg, fix_ssa, NULL, &env);
 443                 for (i = get_Block_n_cfgpreds(endbb) - 1; i >= 0; --i) {
 444                         ir_node *node = skip_Proj(get_Block_cfgpred(endbb, i));
 445                         ir_node *bb   = get_Block_cfgpred_block(endbb, i);
 446                         ir_node *sync;
 447                         ir_node *ins[2];
 448
 449                         switch (get_irn_opcode(node)) {
 450                         case iro_Return:
 451                                 ins[0] = get_irn_link(bb);
 452                                 ins[1] = get_Return_mem(node);
 453                                 sync   = new_r_Sync(irg, bb, 2, ins);
 454                                 set_Return_mem(node, sync);
 455                                 break;
 456                         case iro_Raise:
 457                                 ins[0] = get_irn_link(bb);
 458                                 ins[1] = get_Raise_mem(node);
 459                                 sync   = new_r_Sync(irg, bb, 2, ins);
 460                                 set_Raise_mem(node, sync);
 461                                 break;
 462                         default:
 463                                 /* a fragile's op exception. There should be another path to End,
 464                                    so ignore it */
 465                                 assert(is_fragile_op(node) && "unexpected End control flow predecessor");
 466                         }
 467                 }
 468         }
 469         set_array_entity_values(bblock_id, tarval_array, n_blocks);
 470
 471         if (flags & profile_with_locations) {
 472                 /* build the initializer for the locations */
 473                 rem = current_ir_graph;
 474                 current_ir_graph = get_const_code_irg();
 475                 ent = get_array_element_entity(loc_type);
 476                 set_entity_variability(ent_locations, variability_constant);
 477                 for (i = 0; i < n_blocks; ++i) {
 478                         compound_graph_path *path;
 479                         tarval *tv;
 480                         ir_node *n;
 481
 482                         /* lineno */
 483                         path = new_compound_graph_path(loc_type, 2);
 484                         set_compound_graph_path_array_index(path, 0, i);
 485                         set_compound_graph_path_node(path, 0, ent);
 486                         set_compound_graph_path_node(path, 1, loc_lineno);
 487                         tv = new_tarval_from_long(wd.locs[i].lineno, mode_Iu);
 488                         add_compound_ent_value_w_path(ent_locations, new_Const(mode_Iu, tv), path);
 489
 490                         /* name */
 491                         path = new_compound_graph_path(loc_type, 2);
 492                         set_compound_graph_path_array_index(path, 0, i);
 493                         set_compound_graph_path_node(path, 0, ent);
 494                         set_compound_graph_path_node(path, 1, loc_name);
 495                         if (wd.locs[i].fname) {
 496                                 sym.entity_p = wd.locs[i].fname;
 497                                 n = new_SymConst(sym, symconst_addr_ent);
 498                         } else {
 499                                 n = new_Const(mode_P_data, get_mode_null(mode_P_data));
 500                         }
 501                         add_compound_ent_value_w_path(ent_locations, n, path);
 502                 }
 503                 pmap_destroy(wd.fname_map);
 504         }
 505         return gen_initializer_irg(ent_filename, bblock_id, bblock_counts, n_blocks);
 506 }
 507
 508 static void
 509 profile_node_info(void *ctx, FILE *f, const ir_node *irn)
 510 {
 511         if(is_Block(irn)) {
 512                 fprintf(f, "profiled execution count: %u\n", be_profile_get_block_execcount(irn));
 513         }
 514 }
 515
 516 static void
 517 register_vcg_hook(void)
 518 {
 519         memset(&hook, 0, sizeof(hook));
 520         hook.hook._hook_node_info = profile_node_info;
 521         register_hook(hook_node_info, &hook);
 522 }
 523
 524 static void
 525 unregister_vcg_hook(void)
 526 {
 527         unregister_hook(hook_node_info, &hook);
 528 }
 529
 530 /**
 531  * Reads the corresponding profile info file if it exists and returns a
 532  * profile info struct
 533  */
 534 void
 535 be_profile_read(const char *filename)
 536 {
 537         FILE   *f;
 538         char    buf[8];
 539         size_t  ret;
 540
 541         f = fopen(filename, "r");
 542         if(f == NULL) {
 543                 return;
 544         }
 545         printf("found profile data '%s'.\n", filename);
 546
 547         /* check magic */
 548         ret = fread(buf, 8, 1, f);
 549         if(ret == 0 || strncmp(buf, "firmprof", 8) != 0) {
 550                 return;
 551         }
 552
 553         if(profile) be_profile_free();
 554         profile = new_set(cmp_execcount, 16);
 555
 556         do {
 557                 execcount_t  query;
 558                 ret = fread(&query, sizeof(unsigned int), 2, f);
 559
 560                 if(ret != 2) break;
 561
 562                 set_insert(profile, &query, sizeof(query), query.block);
 563         } while(1);
 564
 565         fclose(f);
 566         register_vcg_hook();
 567 }
 568
 569 /**
 570  * Frees the profile info
 571  */
 572 void
 573 be_profile_free(void)
 574 {
 575         if(profile) {
 576                 unregister_vcg_hook();
 577                 del_set(profile);
 578         }
 579 }
 580
 581 /**
 582  * Tells whether profile module has acquired data
 583  */
 584 int
 585 be_profile_has_data(void)
 586 {
 587         return (profile != NULL);
 588 }
 589
 590 /**
 591  * Get block execution count as determined be profiling
 592  */
 593 unsigned int
 594 be_profile_get_block_execcount(const ir_node *block)
 595 {
 596         execcount_t *ec, query;
 597
 598         if(!profile)
 599                 return 1;
 600
 601         query.block = get_irn_node_nr(block);
 602         ec = set_find(profile, &query, sizeof(query), get_irn_node_nr(block));
 603
 604         if(ec != NULL) {
 605                 return ec->count;
 606         } else {
 607                 ir_fprintf(stderr, "Warning: Profile contains no data for %+F\n",
 608                            block);
 609                 return 1;
 610         }
 611 }
 612
 613 typedef struct _intialize_execfreq_env_t {
 614         ir_graph *irg;
 615         ir_exec_freq *execfreqs;
 616         double freq_factor;
 617 } initialize_execfreq_env_t;
 618
 619 // minimal execution frequency (an execfreq of 0 confuses algos)
 620 static const double MIN_EXECFREQ = 0.00001;
 621
 622 static void initialize_execfreq(ir_node *block, void *data) {
 623         initialize_execfreq_env_t *env = data;
 624         double freq;
 625
 626         if(block == get_irg_start_block(env->irg)
 627            || block == get_irg_end_block(env->irg)) {
 628                 freq = 1.0;
 629         } else {
 630                 freq = be_profile_get_block_execcount(block);
 631                 freq *= env->freq_factor;
 632                 if(freq < MIN_EXECFREQ)
 633                         freq = MIN_EXECFREQ;
 634         }
 635
 636         set_execfreq(env->execfreqs, block, freq);
 637 }
 638
 639 ir_exec_freq *be_create_execfreqs_from_profile(ir_graph *irg)
 640 {
 641         ir_node *block2 = NULL;
 642         ir_node *start_block;
 643         const ir_edge_t *edge;
 644         initialize_execfreq_env_t env;
 645         unsigned count;
 646
 647         env.irg = irg;
 648         env.execfreqs = create_execfreq(irg);
 649
 650         // find the successor to the start block
 651         start_block = get_irg_start_block(irg);
 652         foreach_block_succ(start_block, edge) {
 653                 ir_node *succ = get_edge_src_irn(edge);
 654                 if(succ != start_block) {
 655                         block2 = succ;
 656                         break;
 657                 }
 658         }
 659         assert(block2 != NULL);
 660
 661         count = be_profile_get_block_execcount(block2);
 662         if(count == 0) {
 663                 // the function was never executed, so fallback to estimated freqs
 664                 free_execfreq(env.execfreqs);
 665
 666                 return compute_execfreq(irg, 10);
 667         }
 668
 669         env.freq_factor = 1.0 / count;
 670         irg_block_walk_graph(irg, initialize_execfreq, NULL, &env);
 671
 672         return env.execfreqs;
 673 }