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