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 "entity.h"
  41 #include "irprintf.h"
  42 #include "irgwalk.h"
  43 #include "irdump_t.h"
  44 #include "irnode_t.h"
  45 #include "ircons_t.h"
  46 #include "irloop_t.h"
  47 #include "iredges.h"
  48 #include "execfreq.h"
  49 #include "irvrfy.h"
  50 #include "type.h"
  51
  52 #include "be_t.h"
  53 #include "belive_t.h"
  54 #include "besched_t.h"
  55 #include "beirgmod.h"
  56 #include "bearch_t.h"
  57 #include "beabi.h"
  58 #include "benode_t.h"
  59 #include "beutil.h"
  60 #include "ircons.h"
  61 #include "irhooks.h"
  62 #include "iredges.h"
  63
  64 #include "bechordal_t.h"
  65
  66 #include "beprofile.h"
  67
  68 /** An entry in the id-to-location map */
  69 typedef struct loc_entry {
  70         ir_entity    *fname;   /**< the entity holding the file name */
  71         unsigned int lineno;   /**< line number */
  72 } loc_entry;
  73
  74 typedef struct _block_id_walker_data_t {
  75         tarval         **array;    /**< the entity the holds the block counts */
  76         unsigned int   id;         /**< current block id number */
  77         ir_node        *symconst;  /**< the SymConst representing array */
  78         pmap           *fname_map; /**< set containing all found filenames */
  79         loc_entry      *locs;      /**< locations */
  80         ir_type        *tp_char;   /**< the character type */
  81         unsigned       flags;      /**< profile flags */
  82 } block_id_walker_data_t;
  83
  84 typedef struct _execcount_t {
  85         unsigned int block;
  86         unsigned int count;
  87 } execcount_t;
  88
  89 static int
  90 cmp_execcount(const void * a, const void * b, size_t size)
  91 {
  92         return ((execcount_t*)a)->block != ((execcount_t*)b)->block;
  93 }
  94
  95 static void
  96 block_counter(ir_node * bb, void * data)
  97 {
  98         unsigned int  *count = data;
  99         *count = *count + 1;
 100 }
 101
 102 static unsigned int
 103 count_blocks(ir_graph * irg)
 104 {
 105         unsigned int count = 0;
 106
 107         irg_block_walk_graph(irg, block_counter, NULL, &count);
 108         return count;
 109 }
 110
 111 /* keep the execcounts here because they are only read once per compiler run */
 112 static set * profile = NULL;
 113 static hook_entry_t hook;
 114
 115 /**
 116  * Instrument a block with code needed for profiling
 117  */
 118 static void
 119 instrument_block(ir_node * bb, ir_node * address, unsigned int id)
 120 {
 121         ir_graph *irg = get_irn_irg(bb);
 122         ir_node  *start_block = get_irg_start_block(irg);
 123         ir_node  *load, *store, *offset, *add, *projm, *proji, *unknown;
 124         ir_node  *cnst;
 125
 126         /**
 127          * We can't instrument the start and end block as there are no real
 128          * instructions in these blocks
 129          */
 130         if(bb == start_block || bb == get_irg_end_block(irg))
 131                 return;
 132
 133         unknown = new_r_Unknown(irg, mode_M);
 134         cnst    = new_r_Const_long(irg, start_block, mode_Iu, get_mode_size_bytes(mode_Iu) * id);
 135         offset  = new_r_Add(irg, bb, address, cnst, mode_P);
 136         load    = new_r_Load(irg, bb, unknown, offset, mode_Iu);
 137         projm   = new_r_Proj(irg, bb, load, mode_M, pn_Load_M);
 138         proji   = new_r_Proj(irg, bb, load, mode_Iu, pn_Load_res);
 139         cnst    = new_r_Const_long(irg, start_block, mode_Iu, 1);
 140         add     = new_r_Add(irg, bb, proji, cnst, mode_Iu);
 141         store   = new_r_Store(irg, bb, projm, offset, add);
 142         projm   = new_r_Proj(irg, bb, store, mode_M, pn_Store_M);
 143         set_irn_link(bb, projm);
 144         set_irn_link(projm, load);
 145 }
 146
 147 typedef struct fix_env {
 148         ir_node *start_block;
 149         ir_node *end_block;
 150 } fix_env;
 151
 152 /**
 153  * SSA Construction for instrumentation code memory
 154  */
 155 static void
 156 fix_ssa(ir_node * bb, void * data)
 157 {
 158         fix_env *env = data;
 159         ir_node *mem;
 160         int     arity = get_Block_n_cfgpreds(bb);
 161
 162         /* start and end block are not instrumented, skip! */
 163         if (bb == env->start_block || bb == env->end_block)
 164                 return;
 165
 166         if (arity == 1) {
 167                 mem = get_irn_link(get_Block_cfgpred_block(bb, 0));
 168         } else {
 169                 int n;
 170                 ir_node **ins;
 171                 ir_graph *irg = current_ir_graph;
 172
 173                 NEW_ARR_A(ir_node*, ins, arity);
 174                 for (n = arity - 1; n >= 0; --n) {
 175                         ins[n] = get_irn_link(get_Block_cfgpred_block(bb, n));
 176                 }
 177                 mem = new_r_Phi(irg, bb, arity, ins, mode_M);
 178         }
 179         set_Load_mem(get_irn_link(get_irn_link(bb)), mem);
 180 }
 181
 182
 183 /**
 184  * Generates a new irg which calls the initializer
 185  *
 186  * Pseudocode:
 187  *       void __firmprof_initializer(void) { __init_firmprof(ent_filename, bblock_id, bblock_counts, n_blocks); }
 188  */
 189 static ir_graph *
 190 gen_initializer_irg(ir_entity * ent_filename, ir_entity * bblock_id, ir_entity * bblock_counts, int n_blocks)
 191 {
 192         ir_node *start_block;
 193
 194         ir_node   *ins[4];
 195         ident     *name = new_id_from_str("__firmprof_initializer");
 196         ir_entity *ent  = new_entity(get_glob_type(), name, new_type_method(name, 0, 0));
 197         ir_node   *ret, *call, *symconst;
 198         symconst_symbol sym;
 199
 200         ident     *init_name = new_id_from_str("__init_firmprof");
 201         ir_type   *init_type = new_type_method(init_name, 4, 0);
 202         ir_type   *uint, *uintptr, *string;
 203         ir_entity *init_ent;
 204         ir_graph  *irg;
 205         ir_node   *bb;
 206         ir_type   *empty_frame_type;
 207
 208         set_entity_ld_ident(ent, name);
 209
 210         uint    = new_type_primitive(new_id_from_str("__uint"), mode_Iu);
 211         uintptr = new_type_pointer(new_id_from_str("__uintptr"), uint, mode_P);
 212         string  = new_type_pointer(new_id_from_str("__charptr"), new_type_primitive(new_id_from_str("__char"), mode_Bs), mode_P);
 213
 214         set_method_param_type(init_type, 0, string);
 215         set_method_param_type(init_type, 1, uintptr);
 216         set_method_param_type(init_type, 2, uintptr);
 217         set_method_param_type(init_type, 3, uint);
 218         init_ent = new_entity(get_glob_type(), init_name, init_type);
 219         set_entity_ld_ident(init_ent, init_name);
 220
 221         irg = new_ir_graph(ent, 0);
 222         empty_frame_type = get_irg_frame_type(irg);
 223         set_type_size_bytes(empty_frame_type, 0);
 224
 225         bb = get_cur_block();
 226
 227         start_block = get_irg_start_block(irg);
 228
 229         sym.entity_p = init_ent;
 230         symconst     = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 231
 232         sym.entity_p = ent_filename;
 233         ins[0] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 234         sym.entity_p = bblock_id;
 235         ins[1] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 236         sym.entity_p = bblock_counts;
 237         ins[2] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
 238         ins[3] = new_r_Const_long(irg, start_block, mode_Iu, n_blocks);
 239
 240         call = new_r_Call(irg, bb, get_irg_initial_mem(irg), symconst, 4, ins, init_type);
 241         ret = new_r_Return(irg, bb, new_r_Proj(irg, bb, call, mode_M, pn_Call_M_regular), 0, NULL);
 242         mature_immBlock(bb);
 243
 244         add_immBlock_pred(get_irg_end_block(irg), ret);
 245         mature_immBlock(get_irg_end_block(irg));
 246
 247         irg_finalize_cons(irg);
 248
 249         return irg;
 250 }
 251
 252 /**
 253  * Create the location data for the given debug info.
 254  */
 255 static void create_location_data(dbg_info *dbg, block_id_walker_data_t *wd)
 256 {
 257         unsigned lineno;
 258         const char *fname = be_retrieve_dbg_info(dbg, &lineno);
 259
 260         if (fname) {
 261                 pmap_entry *entry = pmap_find(wd->fname_map, (void *)fname);
 262                 ir_entity  *ent;
 263
 264                 if (! entry) {
 265                         static unsigned nr = 0;
 266                         ident   *id;
 267                         char    buf[128];
 268                         ir_type *arr;
 269                         int     i, len = strlen(fname) + 1;
 270                         tarval  **tarval_string;
 271
 272                         snprintf(buf, sizeof(buf), "firm_name_arr.%d", nr);
 273                         arr = new_type_array(new_id_from_str(buf), 1, wd->tp_char);
 274                         set_array_bounds_int(arr, 0, 0, len);
 275
 276                         snprintf(buf, sizeof(buf), "__firm_name.%d", nr++);
 277                         id = new_id_from_str(buf);
 278                         ent = new_entity(get_glob_type(), id, arr);
 279                         set_entity_ld_ident(ent, id);
 280
 281                         pmap_insert(wd->fname_map, (void *)fname, ent);
 282
 283                         /* initialize file name string constant */
 284                         tarval_string = alloca(sizeof(*tarval_string) * (len));
 285                         for (i = 0; i < len; ++i) {
 286                                 tarval_string[i] = new_tarval_from_long(fname[i], mode_Bs);
 287                         }
 288                         set_entity_variability(ent, variability_constant);
 289                         set_array_entity_values(ent, tarval_string, len);
 290                 } else {
 291                         ent = entry->value;
 292                 }
 293                 wd->locs[wd->id].fname  = ent;
 294                 wd->locs[wd->id].lineno = lineno;
 295         } else {
 296                 wd->locs[wd->id].fname  = NULL;
 297                 wd->locs[wd->id].lineno = 0;
 298         }
 299 }
 300
 301 /**
 302  * Walker: assigns an ID to every block.
 303  * Builds the string table
 304  */
 305 static void
 306 block_id_walker(ir_node * bb, void * data)
 307 {
 308         block_id_walker_data_t *wd = data;
 309
 310         wd->array[wd->id] = new_tarval_from_long(get_irn_node_nr(bb), mode_Iu);
 311         instrument_block(bb, wd->symconst, wd->id);
 312
 313         if (wd->flags & profile_with_locations) {
 314                 dbg_info *dbg = get_irn_dbg_info(bb);
 315                 create_location_data(dbg, wd);
 316         }
 317         ++wd->id;
 318 }
 319
 320 #define IDENT(x)        new_id_from_chars(x, sizeof(x) - 1)
 321
 322 ir_graph *
 323 be_profile_instrument(const char *filename, unsigned flags)
 324 {
 325         int n, i;
 326         int n_blocks = 0;
 327         ir_entity *bblock_id;
 328         ir_entity *bblock_counts;
 329         ir_entity *ent_filename;
 330         ir_entity *ent_locations = NULL;
 331         ir_entity *loc_lineno = NULL;
 332         ir_entity *loc_name = NULL;
 333         ir_entity *ent;
 334         ir_type *array_type;
 335         ir_type *uint_type;
 336         ir_type *string_type;
 337         ir_type *character_type;
 338         ir_type *loc_type = NULL;
 339         ir_type *charptr_type;
 340         ir_type *gtp;
 341         tarval **tarval_array;
 342         tarval **tarval_string;
 343         tarval *tv;
 344         int filename_len = strlen(filename)+1;
 345         ident *cur_ident;
 346         int align_l, align_n, size;
 347         ir_graph *rem;
 348         block_id_walker_data_t  wd;
 349         symconst_symbol sym;
 350
 351         /* count the number of block first */
 352         for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
 353                 ir_graph *irg = get_irp_irg(n);
 354
 355                 n_blocks += count_blocks(irg);
 356         }
 357
 358         /* create all the necessary types and entities. Note that the
 359            types must have a fixed layout, because we already running in the
 360            backend */
 361         uint_type      = new_type_primitive(IDENT("__uint"), mode_Iu);
 362         set_type_alignment_bytes(uint_type, get_type_size_bytes(uint_type));
 363         array_type     = new_type_array(IDENT("__block_info_array"), 1, uint_type);
 364         set_array_bounds_int(array_type, 0, 0, n_blocks);
 365
 366         character_type = new_type_primitive(IDENT("__char"), mode_Bs);
 367         string_type    = new_type_array(IDENT("__filename"), 1, character_type);
 368         set_array_bounds_int(string_type, 0, 0, filename_len);
 369
 370         gtp            = get_glob_type();
 371
 372         cur_ident      = IDENT("__FIRMPROF__BLOCK_IDS");
 373         bblock_id      = new_entity(gtp, cur_ident, array_type);
 374         set_entity_ld_ident(bblock_id, cur_ident);
 375         set_entity_variability(bblock_id, variability_initialized);
 376
 377         cur_ident      = IDENT("__FIRMPROF__BLOCK_COUNTS");
 378         bblock_counts  = new_entity(gtp, cur_ident, array_type);
 379         set_entity_ld_ident(bblock_counts, cur_ident);
 380         set_entity_variability(bblock_counts, variability_initialized);
 381
 382         cur_ident      = IDENT("__FIRMPROF__FILE_NAME");
 383         ent_filename   = new_entity(gtp, cur_ident, string_type);
 384         set_entity_ld_ident(ent_filename, cur_ident);
 385
 386         if (flags & profile_with_locations) {
 387                 loc_type       = new_type_struct(IDENT("__location"));
 388                 loc_lineno     = new_entity(loc_type, IDENT("lineno"), uint_type);
 389                 align_l        = get_type_alignment_bytes(uint_type);
 390                 size           = get_type_size_bytes(uint_type);
 391                 set_entity_offset(loc_lineno, 0);
 392
 393                 charptr_type   = new_type_pointer(IDENT("__charptr"), character_type, mode_P_data);
 394                 align_n        = get_type_size_bytes(charptr_type);
 395                 set_type_alignment_bytes(charptr_type, align_n);
 396                 loc_name       = new_entity(loc_type, IDENT("name"), charptr_type);
 397                 size           = (size + align_n - 1) & -align_n;
 398                 set_entity_offset(loc_name, size);
 399                 size          += align_n;
 400
 401                 if (align_n > align_l)
 402                         align_l = align_n;
 403                 size = (size + align_l - 1) & -align_l;
 404                 set_type_size_bytes(loc_type, size);
 405                 set_type_state(loc_type, layout_fixed);
 406
 407                 loc_type = new_type_array(IDENT("__locarray"), 1, loc_type);
 408                 set_array_bounds_int(string_type, 0, 0, n_blocks);
 409
 410                 cur_ident      = IDENT("__FIRMPROF__LOCATIONS");
 411                 ent_locations   = new_entity(gtp, cur_ident, loc_type);
 412                 set_entity_ld_ident(ent_locations, cur_ident);
 413         }
 414
 415         /* initialize count array */
 416         NEW_ARR_A(tarval *, tarval_array, n_blocks);
 417         tv = get_tarval_null(mode_Iu);
 418         for (i = 0; i < n_blocks; ++i) {
 419                 tarval_array[i] = tv;
 420         }
 421         set_array_entity_values(bblock_counts, tarval_array, n_blocks);
 422
 423         /* initialize function name string constant */
 424         tarval_string = alloca(sizeof(*tarval_string) * (filename_len));
 425         for (i = 0; i < filename_len; ++i) {
 426                 tarval_string[i] = new_tarval_from_long(filename[i], mode_Bs);
 427         }
 428         set_entity_variability(ent_filename, variability_constant);
 429         set_array_entity_values(ent_filename, tarval_string, filename_len);
 430
 431         /* initialize block id array and instrument blocks */
 432         wd.array     = tarval_array;
 433         wd.id        = 0;
 434         wd.tp_char   = character_type;
 435         wd.flags     = flags;
 436         if (flags & profile_with_locations) {
 437                 wd.fname_map = pmap_create();
 438                 NEW_ARR_A(loc_entry, wd.locs, n_blocks);
 439         }
 440
 441         for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
 442                 ir_graph      *irg = get_irp_irg(n);
 443                 int            i;
 444                 ir_node       *endbb = get_irg_end_block(irg);
 445                 fix_env       env;
 446
 447                 set_current_ir_graph(irg);
 448
 449                 /* generate a symbolic constant pointing to the count array */
 450                 sym.entity_p = bblock_counts;
 451                 wd.symconst  = new_r_SymConst(irg, get_irg_start_block(irg), sym, symconst_addr_ent);
 452
 453                 irg_block_walk_graph(irg, block_id_walker, NULL, &wd);
 454                 env.start_block = get_irg_start_block(irg);
 455                 env.end_block   = get_irg_end_block(irg);
 456                 set_irn_link(env.start_block, get_irg_no_mem(irg));
 457                 irg_block_walk_graph(irg, fix_ssa, NULL, &env);
 458                 for (i = get_Block_n_cfgpreds(endbb) - 1; i >= 0; --i) {
 459                         ir_node *node = skip_Proj(get_Block_cfgpred(endbb, i));
 460                         ir_node *bb   = get_Block_cfgpred_block(endbb, i);
 461                         ir_node *sync;
 462                         ir_node *ins[2];
 463
 464                         switch (get_irn_opcode(node)) {
 465                         case iro_Return:
 466                                 ins[0] = get_irn_link(bb);
 467                                 ins[1] = get_Return_mem(node);
 468                                 sync   = new_r_Sync(irg, bb, 2, ins);
 469                                 set_Return_mem(node, sync);
 470                                 break;
 471                         case iro_Raise:
 472                                 ins[0] = get_irn_link(bb);
 473                                 ins[1] = get_Raise_mem(node);
 474                                 sync   = new_r_Sync(irg, bb, 2, ins);
 475                                 set_Raise_mem(node, sync);
 476                                 break;
 477                         default:
 478                                 /* a fragile's op exception. There should be another path to End,
 479                                    so ignore it */
 480                                 assert(is_fragile_op(node) && "unexpected End control flow predecessor");
 481                         }
 482                 }
 483         }
 484         set_array_entity_values(bblock_id, tarval_array, n_blocks);
 485
 486         if (flags & profile_with_locations) {
 487                 /* build the initializer for the locations */
 488                 rem = current_ir_graph;
 489                 current_ir_graph = get_const_code_irg();
 490                 ent = get_array_element_entity(loc_type);
 491                 set_entity_variability(ent_locations, variability_constant);
 492                 for (i = 0; i < n_blocks; ++i) {
 493                         compound_graph_path *path;
 494                         tarval *tv;
 495                         ir_node *n;
 496
 497                         /* lineno */
 498                         path = new_compound_graph_path(loc_type, 2);
 499                         set_compound_graph_path_array_index(path, 0, i);
 500                         set_compound_graph_path_node(path, 0, ent);
 501                         set_compound_graph_path_node(path, 1, loc_lineno);
 502                         tv = new_tarval_from_long(wd.locs[i].lineno, mode_Iu);
 503                         add_compound_ent_value_w_path(ent_locations, new_Const(mode_Iu, tv), path);
 504
 505                         /* name */
 506                         path = new_compound_graph_path(loc_type, 2);
 507                         set_compound_graph_path_array_index(path, 0, i);
 508                         set_compound_graph_path_node(path, 0, ent);
 509                         set_compound_graph_path_node(path, 1, loc_name);
 510                         if (wd.locs[i].fname) {
 511                                 sym.entity_p = wd.locs[i].fname;
 512                                 n = new_SymConst(sym, symconst_addr_ent);
 513                         } else {
 514                                 n = new_Const(mode_P_data, get_mode_null(mode_P_data));
 515                         }
 516                         add_compound_ent_value_w_path(ent_locations, n, path);
 517                 }
 518                 pmap_destroy(wd.fname_map);
 519         }
 520         return gen_initializer_irg(ent_filename, bblock_id, bblock_counts, n_blocks);
 521 }
 522
 523 static void
 524 profile_node_info(void *ctx, FILE *f, const ir_node *irn)
 525 {
 526         if(is_Block(irn)) {
 527                 fprintf(f, "profiled execution count: %u\n", be_profile_get_block_execcount(irn));
 528         }
 529 }
 530
 531 static void
 532 register_vcg_hook(void)
 533 {
 534         memset(&hook, 0, sizeof(hook));
 535         hook.hook._hook_node_info = profile_node_info;
 536         register_hook(hook_node_info, &hook);
 537 }
 538
 539 static void
 540 unregister_vcg_hook(void)
 541 {
 542         unregister_hook(hook_node_info, &hook);
 543 }
 544
 545 /**
 546  * Reads the corresponding profile info file if it exists and returns a
 547  * profile info struct
 548  */
 549 void
 550 be_profile_read(const char *filename)
 551 {
 552         FILE   *f;
 553         char    buf[8];
 554         size_t  ret;
 555
 556         f = fopen(filename, "r");
 557         if(f == NULL) {
 558                 return;
 559         }
 560         printf("found profile data '%s'.\n", filename);
 561
 562         /* check magic */
 563         ret = fread(buf, 8, 1, f);
 564         if(ret == 0 || strncmp(buf, "firmprof", 8) != 0) {
 565                 return;
 566         }
 567
 568         if(profile) be_profile_free();
 569         profile = new_set(cmp_execcount, 16);
 570
 571         do {
 572                 execcount_t  query;
 573                 ret = fread(&query, sizeof(unsigned int), 2, f);
 574
 575                 if(ret != 2) break;
 576
 577                 set_insert(profile, &query, sizeof(query), query.block);
 578         } while(1);
 579
 580         fclose(f);
 581         register_vcg_hook();
 582 }
 583
 584 /**
 585  * Frees the profile info
 586  */
 587 void
 588 be_profile_free(void)
 589 {
 590         if(profile) {
 591                 unregister_vcg_hook();
 592                 del_set(profile);
 593         }
 594 }
 595
 596 /**
 597  * Tells whether profile module has acquired data
 598  */
 599 int
 600 be_profile_has_data(void)
 601 {
 602         return (profile != NULL);
 603 }
 604
 605 /**
 606  * Get block execution count as determined be profiling
 607  */
 608 unsigned int
 609 be_profile_get_block_execcount(const ir_node *block)
 610 {
 611         execcount_t *ec, query;
 612
 613         if(!profile)
 614                 return 1;
 615
 616         query.block = get_irn_node_nr(block);
 617         ec = set_find(profile, &query, sizeof(query), get_irn_node_nr(block));
 618
 619         if(ec != NULL) {
 620                 return ec->count;
 621         } else {
 622                 ir_fprintf(stderr, "Warning: Profile contains no data for %+F\n",
 623                            block);
 624                 return 1;
 625         }
 626 }
 627
 628 typedef struct _intialize_execfreq_env_t {
 629         ir_graph *irg;
 630         ir_exec_freq *execfreqs;
 631         double freq_factor;
 632 } initialize_execfreq_env_t;
 633
 634 // minimal execution frequency (an execfreq of 0 confuses algos)
 635 static const double MIN_EXECFREQ = 0.00001;
 636
 637 static void initialize_execfreq(ir_node *block, void *data) {
 638         initialize_execfreq_env_t *env = data;
 639         double freq;
 640
 641         if(block == get_irg_start_block(env->irg)
 642            || block == get_irg_end_block(env->irg)) {
 643                 freq = 1.0;
 644         } else {
 645                 freq = be_profile_get_block_execcount(block);
 646                 freq *= env->freq_factor;
 647                 if(freq < MIN_EXECFREQ)
 648                         freq = MIN_EXECFREQ;
 649         }
 650
 651         set_execfreq(env->execfreqs, block, freq);
 652 }
 653
 654 ir_exec_freq *be_create_execfreqs_from_profile(ir_graph *irg)
 655 {
 656         ir_node *block2 = NULL;
 657         ir_node *start_block;
 658         const ir_edge_t *edge;
 659         initialize_execfreq_env_t env;
 660         unsigned count;
 661
 662         env.irg = irg;
 663         env.execfreqs = create_execfreq(irg);
 664
 665         // find the successor to the start block
 666         start_block = get_irg_start_block(irg);
 667         foreach_block_succ(start_block, edge) {
 668                 ir_node *succ = get_edge_src_irn(edge);
 669                 if(succ != start_block) {
 670                         block2 = succ;
 671                         break;
 672                 }
 673         }
 674         assert(block2 != NULL);
 675
 676         count = be_profile_get_block_execcount(block2);
 677         if(count == 0) {
 678                 // the function was never executed, so fallback to estimated freqs
 679                 free_execfreq(env.execfreqs);
 680
 681                 return compute_execfreq(irg, 10);
 682         }
 683
 684         env.freq_factor = 1.0 / count;
 685         irg_block_walk_graph(irg, initialize_execfreq, NULL, &env);
 686
 687         return env.execfreqs;
 688 }