gcc/tree-profile.c

   1 /* Calculate branch probabilities, and basic block execution counts.
   2    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999,
   3    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
   4    Free Software Foundation, Inc.
   5    Contributed by James E. Wilson, UC Berkeley/Cygnus Support;
   6    based on some ideas from Dain Samples of UC Berkeley.
   7    Further mangling by Bob Manson, Cygnus Support.
   8    Converted to use trees by Dale Johannesen, Apple Computer.
   9
  10 This file is part of GCC.
  11
  12 GCC is free software; you can redistribute it and/or modify it under
  13 the terms of the GNU General Public License as published by the Free
  14 Software Foundation; either version 3, or (at your option) any later
  15 version.
  16
  17 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  18 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20 for more details.
  21
  22 You should have received a copy of the GNU General Public License
  23 along with GCC; see the file COPYING3.  If not see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 /* Generate basic block profile instrumentation and auxiliary files.
  27    Tree-based version.  See profile.c for overview.  */
  28
  29 #include "config.h"
  30 #include "system.h"
  31 #include "coretypes.h"
  32 #include "tm.h"
  33 #include "rtl.h"
  34 #include "flags.h"
  35 #include "output.h"
  36 #include "regs.h"
  37 #include "expr.h"
  38 #include "function.h"
  39 #include "toplev.h"
  40 #include "coverage.h"
  41 #include "tree.h"
  42 #include "tree-flow.h"
  43 #include "tree-dump.h"
  44 #include "tree-pass.h"
  45 #include "timevar.h"
  46 #include "value-prof.h"
  47 #include "ggc.h"
  48 #include "cgraph.h"
  49
  50 static GTY(()) tree gcov_type_node;
  51 static GTY(()) tree gcov_type_tmp_var;
  52 static GTY(()) tree tree_interval_profiler_fn;
  53 static GTY(()) tree tree_pow2_profiler_fn;
  54 static GTY(()) tree tree_one_value_profiler_fn;
  55 static GTY(()) tree tree_indirect_call_profiler_fn;
  56 static GTY(()) tree tree_average_profiler_fn;
  57 static GTY(()) tree tree_ior_profiler_fn;
  58 \f
  59
  60 static GTY(()) tree ic_void_ptr_var;
  61 static GTY(()) tree ic_gcov_type_ptr_var;
  62 static GTY(()) tree ptr_void;
  63
  64 /* Do initialization work for the edge profiler.  */
  65
  66 /* Add code:
  67    static gcov* __gcov_indirect_call_counters; // pointer to actual counter
  68    static void* __gcov_indirect_call_callee; // actual callee addres
  69 */
  70 static void
  71 tree_init_ic_make_global_vars (void)
  72 {
  73   tree  gcov_type_ptr;
  74
  75   ptr_void = build_pointer_type (void_type_node);
  76
  77   ic_void_ptr_var
  78     = build_decl (VAR_DECL,
  79                   get_identifier ("__gcov_indirect_call_callee"),
  80                   ptr_void);
  81   TREE_STATIC (ic_void_ptr_var) = 1;
  82   TREE_PUBLIC (ic_void_ptr_var) = 0;
  83   DECL_ARTIFICIAL (ic_void_ptr_var) = 1;
  84   DECL_INITIAL (ic_void_ptr_var) = NULL;
  85   assemble_variable (ic_void_ptr_var, 0, 0, 0);
  86
  87   gcov_type_ptr = build_pointer_type (get_gcov_type ());
  88   ic_gcov_type_ptr_var
  89     = build_decl (VAR_DECL,
  90                   get_identifier ("__gcov_indirect_call_counters"),
  91                   gcov_type_ptr);
  92   TREE_STATIC (ic_gcov_type_ptr_var) = 1;
  93   TREE_PUBLIC (ic_gcov_type_ptr_var) = 0;
  94   DECL_ARTIFICIAL (ic_gcov_type_ptr_var) = 1;
  95   DECL_INITIAL (ic_gcov_type_ptr_var) = NULL;
  96   assemble_variable (ic_gcov_type_ptr_var, 0, 0, 0);
  97 }
  98
  99 static void
 100 tree_init_edge_profiler (void)
 101 {
 102   tree interval_profiler_fn_type;
 103   tree pow2_profiler_fn_type;
 104   tree one_value_profiler_fn_type;
 105   tree gcov_type_ptr;
 106   tree ic_profiler_fn_type;
 107   tree average_profiler_fn_type;
 108
 109   if (!gcov_type_node)
 110     {
 111       gcov_type_node = get_gcov_type ();
 112       gcov_type_ptr = build_pointer_type (gcov_type_node);
 113
 114       /* void (*) (gcov_type *, gcov_type, int, unsigned)  */
 115       interval_profiler_fn_type
 116               = build_function_type_list (void_type_node,
 117                                           gcov_type_ptr, gcov_type_node,
 118                                           integer_type_node,
 119                                           unsigned_type_node, NULL_TREE);
 120       tree_interval_profiler_fn
 121               = build_fn_decl ("__gcov_interval_profiler",
 122                                      interval_profiler_fn_type);
 123
 124       /* void (*) (gcov_type *, gcov_type)  */
 125       pow2_profiler_fn_type
 126               = build_function_type_list (void_type_node,
 127                                           gcov_type_ptr, gcov_type_node,
 128                                           NULL_TREE);
 129       tree_pow2_profiler_fn = build_fn_decl ("__gcov_pow2_profiler",
 130                                                    pow2_profiler_fn_type);
 131
 132       /* void (*) (gcov_type *, gcov_type)  */
 133       one_value_profiler_fn_type
 134               = build_function_type_list (void_type_node,
 135                                           gcov_type_ptr, gcov_type_node,
 136                                           NULL_TREE);
 137       tree_one_value_profiler_fn
 138               = build_fn_decl ("__gcov_one_value_profiler",
 139                                      one_value_profiler_fn_type);
 140
 141       tree_init_ic_make_global_vars ();
 142
 143       /* void (*) (gcov_type *, gcov_type, void *, void *)  */
 144       ic_profiler_fn_type
 145                = build_function_type_list (void_type_node,
 146                                           gcov_type_ptr, gcov_type_node,
 147                                           ptr_void,
 148                                           ptr_void, NULL_TREE);
 149       tree_indirect_call_profiler_fn
 150               = build_fn_decl ("__gcov_indirect_call_profiler",
 151                                      ic_profiler_fn_type);
 152       /* void (*) (gcov_type *, gcov_type)  */
 153       average_profiler_fn_type
 154               = build_function_type_list (void_type_node,
 155                                           gcov_type_ptr, gcov_type_node, NULL_TREE);
 156       tree_average_profiler_fn
 157               = build_fn_decl ("__gcov_average_profiler",
 158                                      average_profiler_fn_type);
 159       tree_ior_profiler_fn
 160               = build_fn_decl ("__gcov_ior_profiler",
 161                                      average_profiler_fn_type);
 162     }
 163 }
 164
 165 /* Output instructions as GIMPLE trees to increment the edge
 166    execution count, and insert them on E.  We rely on
 167    bsi_insert_on_edge to preserve the order.  */
 168
 169 static void
 170 tree_gen_edge_profiler (int edgeno, edge e)
 171 {
 172   tree ref, one, stmt1, stmt2, stmt3;
 173
 174   /* We share one temporary variable declaration per function.  This
 175      gets re-set in tree_profiling.  */
 176   if (gcov_type_tmp_var == NULL_TREE)
 177     gcov_type_tmp_var = create_tmp_var (gcov_type_node, "PROF_edge_counter");
 178   ref = tree_coverage_counter_ref (GCOV_COUNTER_ARCS, edgeno);
 179   one = build_int_cst (gcov_type_node, 1);
 180   stmt1 = build_gimple_modify_stmt (gcov_type_tmp_var, ref);
 181   stmt2 = build_gimple_modify_stmt (gcov_type_tmp_var,
 182                                     build2 (PLUS_EXPR, gcov_type_node,
 183                                             gcov_type_tmp_var, one));
 184   stmt3 = build_gimple_modify_stmt (ref, gcov_type_tmp_var);
 185   bsi_insert_on_edge (e, stmt1);
 186   bsi_insert_on_edge (e, stmt2);
 187   bsi_insert_on_edge (e, stmt3);
 188 }
 189
 190 /* Emits code to get VALUE to instrument at BSI, and returns the
 191    variable containing the value.  */
 192
 193 static tree
 194 prepare_instrumented_value (block_stmt_iterator *bsi,
 195                             histogram_value value)
 196 {
 197   tree val = value->hvalue.value;
 198   return force_gimple_operand_bsi (bsi, fold_convert (gcov_type_node, val),
 199                                    true, NULL_TREE, true, BSI_SAME_STMT);
 200 }
 201
 202 /* Output instructions as GIMPLE trees to increment the interval histogram
 203    counter.  VALUE is the expression whose value is profiled.  TAG is the
 204    tag of the section for counters, BASE is offset of the counter position.  */
 205
 206 static void
 207 tree_gen_interval_profiler (histogram_value value, unsigned tag, unsigned base)
 208 {
 209   tree stmt = value->hvalue.stmt;
 210   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 211   tree ref = tree_coverage_counter_ref (tag, base), ref_ptr;
 212   tree call, val;
 213   tree start = build_int_cst_type (integer_type_node, value->hdata.intvl.int_start);
 214   tree steps = build_int_cst_type (unsigned_type_node, value->hdata.intvl.steps);
 215
 216   ref_ptr = force_gimple_operand_bsi (&bsi,
 217                                       build_addr (ref, current_function_decl),
 218                                       true, NULL_TREE, true, BSI_SAME_STMT);
 219   val = prepare_instrumented_value (&bsi, value);
 220   call = build_call_expr (tree_interval_profiler_fn, 4,
 221                           ref_ptr, val, start, steps);
 222   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 223 }
 224
 225 /* Output instructions as GIMPLE trees to increment the power of two histogram
 226    counter.  VALUE is the expression whose value is profiled.  TAG is the tag
 227    of the section for counters, BASE is offset of the counter position.  */
 228
 229 static void
 230 tree_gen_pow2_profiler (histogram_value value, unsigned tag, unsigned base)
 231 {
 232   tree stmt = value->hvalue.stmt;
 233   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 234   tree ref = tree_coverage_counter_ref (tag, base), ref_ptr;
 235   tree call, val;
 236
 237   ref_ptr = force_gimple_operand_bsi (&bsi,
 238                                       build_addr (ref, current_function_decl),
 239                                       true, NULL_TREE, true, BSI_SAME_STMT);
 240   val = prepare_instrumented_value (&bsi, value);
 241   call = build_call_expr (tree_pow2_profiler_fn, 2, ref_ptr, val);
 242   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 243 }
 244
 245 /* Output instructions as GIMPLE trees for code to find the most common value.
 246    VALUE is the expression whose value is profiled.  TAG is the tag of the
 247    section for counters, BASE is offset of the counter position.  */
 248
 249 static void
 250 tree_gen_one_value_profiler (histogram_value value, unsigned tag, unsigned base)
 251 {
 252   tree stmt = value->hvalue.stmt;
 253   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 254   tree ref = tree_coverage_counter_ref (tag, base), ref_ptr;
 255   tree call, val;
 256
 257   ref_ptr = force_gimple_operand_bsi (&bsi,
 258                                       build_addr (ref, current_function_decl),
 259                                       true, NULL_TREE, true, BSI_SAME_STMT);
 260   val = prepare_instrumented_value (&bsi, value);
 261   call = build_call_expr (tree_one_value_profiler_fn, 2, ref_ptr, val);
 262   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 263 }
 264
 265
 266 /* Output instructions as GIMPLE trees for code to find the most
 267    common called function in indirect call.
 268    VALUE is the call expression whose indirect callee is profiled.
 269    TAG is the tag of the section for counters, BASE is offset of the
 270    counter position.  */
 271
 272 static void
 273 tree_gen_ic_profiler (histogram_value value, unsigned tag, unsigned base)
 274 {
 275   tree tmp1, stmt1, stmt2, stmt3;
 276   tree stmt = value->hvalue.stmt;
 277   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 278   tree ref = tree_coverage_counter_ref (tag, base), ref_ptr;
 279
 280   ref_ptr = force_gimple_operand_bsi (&bsi,
 281                                       build_addr (ref, current_function_decl),
 282                                       true, NULL_TREE, true, BSI_SAME_STMT);
 283
 284   /* Insert code:
 285
 286     __gcov_indirect_call_counters = get_relevant_counter_ptr ();
 287     __gcov_indirect_call_callee = (void *) indirect call argument;
 288    */
 289
 290   tmp1 = create_tmp_var (ptr_void, "PROF");
 291   stmt1 = build_gimple_modify_stmt (ic_gcov_type_ptr_var, ref_ptr);
 292   stmt2 = build_gimple_modify_stmt (tmp1, unshare_expr (value->hvalue.value));
 293   stmt3 = build_gimple_modify_stmt (ic_void_ptr_var, tmp1);
 294
 295   bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
 296   bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
 297   bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
 298 }
 299
 300
 301 /* Output instructions as GIMPLE trees for code to find the most
 302    common called function in indirect call. Insert instructions at the
 303    beginning of every possible called function.
 304   */
 305
 306 static void
 307 tree_gen_ic_func_profiler (void)
 308 {
 309   struct cgraph_node * c_node = cgraph_node (current_function_decl);
 310   block_stmt_iterator bsi;
 311   edge e;
 312   basic_block bb;
 313   edge_iterator ei;
 314   tree stmt1;
 315   tree tree_uid, cur_func;
 316
 317   if (flag_unit_at_a_time)
 318     {
 319       if (!c_node->needed)
 320         return;
 321     }
 322
 323   tree_init_edge_profiler ();
 324
 325   FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
 326     {
 327       bb = split_edge (e);
 328       bsi = bsi_start (bb);
 329       cur_func = force_gimple_operand_bsi (&bsi,
 330                                            build_addr (current_function_decl,
 331                                                        current_function_decl),
 332                                            true, NULL_TREE,
 333                                            true, BSI_SAME_STMT);
 334       tree_uid = build_int_cst (gcov_type_node, c_node->pid);
 335       stmt1 = build_call_expr (tree_indirect_call_profiler_fn, 4,
 336                                ic_gcov_type_ptr_var,
 337                                tree_uid,
 338                                cur_func,
 339                                ic_void_ptr_var);
 340       bsi_insert_after (&bsi, stmt1, BSI_NEW_STMT);
 341     }
 342 }
 343
 344 /* Output instructions as GIMPLE trees for code to find the most common value
 345    of a difference between two evaluations of an expression.
 346    VALUE is the expression whose value is profiled.  TAG is the tag of the
 347    section for counters, BASE is offset of the counter position.  */
 348
 349 static void
 350 tree_gen_const_delta_profiler (histogram_value value ATTRIBUTE_UNUSED,
 351                                 unsigned tag ATTRIBUTE_UNUSED,
 352                                 unsigned base ATTRIBUTE_UNUSED)
 353 {
 354   /* FIXME implement this.  */
 355 #ifdef ENABLE_CHECKING
 356   internal_error ("unimplemented functionality");
 357 #endif
 358   gcc_unreachable ();
 359 }
 360
 361 /* Output instructions as GIMPLE trees to increment the average histogram
 362    counter.  VALUE is the expression whose value is profiled.  TAG is the
 363    tag of the section for counters, BASE is offset of the counter position.  */
 364
 365 static void
 366 tree_gen_average_profiler (histogram_value value, unsigned tag, unsigned base)
 367 {
 368   tree stmt = value->hvalue.stmt;
 369   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 370   tree ref = tree_coverage_counter_ref (tag, base), ref_ptr;
 371   tree call, val;
 372
 373   ref_ptr = force_gimple_operand_bsi (&bsi,
 374                                       build_addr (ref, current_function_decl),
 375                                       true, NULL_TREE,
 376                                       true, BSI_SAME_STMT);
 377   val = prepare_instrumented_value (&bsi, value);
 378   call = build_call_expr (tree_average_profiler_fn, 2, ref_ptr, val);
 379   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 380 }
 381
 382 /* Output instructions as GIMPLE trees to increment the ior histogram
 383    counter.  VALUE is the expression whose value is profiled.  TAG is the
 384    tag of the section for counters, BASE is offset of the counter position.  */
 385
 386 static void
 387 tree_gen_ior_profiler (histogram_value value, unsigned tag, unsigned base)
 388 {
 389   tree stmt = value->hvalue.stmt;
 390   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 391   tree ref = tree_coverage_counter_ref (tag, base), ref_ptr;
 392   tree call, val;
 393
 394   ref_ptr = force_gimple_operand_bsi (&bsi,
 395                                       build_addr (ref, current_function_decl),
 396                                       true, NULL_TREE, true, BSI_SAME_STMT);
 397   val = prepare_instrumented_value (&bsi, value);
 398   call = build_call_expr (tree_ior_profiler_fn, 2, ref_ptr, val);
 399   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 400 }
 401
 402 /* Return 1 if tree-based profiling is in effect, else 0.
 403    If it is, set up hooks for tree-based profiling.
 404    Gate for pass_tree_profile.  */
 405
 406 static bool
 407 do_tree_profiling (void)
 408 {
 409   if (profile_arc_flag || flag_test_coverage || flag_branch_probabilities)
 410     {
 411       tree_register_profile_hooks ();
 412       tree_register_value_prof_hooks ();
 413       return true;
 414     }
 415   return false;
 416 }
 417
 418 static unsigned int
 419 tree_profiling (void)
 420 {
 421   /* Don't profile functions produced at destruction time, particularly
 422      the gcov datastructure initializer.  Don't profile if it has been
 423      already instrumented either (when OpenMP expansion creates
 424      child function from already instrumented body).  */
 425   if (cgraph_state == CGRAPH_STATE_FINISHED
 426       || cfun->after_tree_profile)
 427     return 0;
 428
 429   /* Re-set global shared temporary variable for edge-counters.  */
 430   gcov_type_tmp_var = NULL_TREE;
 431
 432   branch_prob ();
 433
 434   if (! flag_branch_probabilities
 435       && flag_profile_values)
 436     tree_gen_ic_func_profiler ();
 437
 438   if (flag_branch_probabilities
 439       && flag_profile_values
 440       && flag_value_profile_transformations)
 441     value_profile_transformations ();
 442   /* The above could hose dominator info.  Currently there is
 443      none coming in, this is a safety valve.  It should be
 444      easy to adjust it, if and when there is some.  */
 445   free_dominance_info (CDI_DOMINATORS);
 446   free_dominance_info (CDI_POST_DOMINATORS);
 447   cfun->after_tree_profile = 1;
 448   return 0;
 449 }
 450
 451 struct tree_opt_pass pass_tree_profile =
 452 {
 453   "tree_profile",                       /* name */
 454   do_tree_profiling,                    /* gate */
 455   tree_profiling,                       /* execute */
 456   NULL,                                 /* sub */
 457   NULL,                                 /* next */
 458   0,                                    /* static_pass_number */
 459   TV_BRANCH_PROB,                       /* tv_id */
 460   PROP_gimple_leh | PROP_cfg,           /* properties_required */
 461   PROP_gimple_leh | PROP_cfg,           /* properties_provided */
 462   0,                                    /* properties_destroyed */
 463   0,                                    /* todo_flags_start */
 464   TODO_verify_stmts | TODO_dump_func,   /* todo_flags_finish */
 465   0                                     /* letter */
 466 };
 467
 468 struct profile_hooks tree_profile_hooks =
 469 {
 470   tree_init_edge_profiler,       /* init_edge_profiler */
 471   tree_gen_edge_profiler,        /* gen_edge_profiler */
 472   tree_gen_interval_profiler,    /* gen_interval_profiler */
 473   tree_gen_pow2_profiler,        /* gen_pow2_profiler */
 474   tree_gen_one_value_profiler,   /* gen_one_value_profiler */
 475   tree_gen_const_delta_profiler, /* gen_const_delta_profiler */
 476   tree_gen_ic_profiler,          /* gen_ic_profiler */
 477   tree_gen_average_profiler,     /* gen_average_profiler */
 478   tree_gen_ior_profiler          /* gen_ior_profiler */
 479 };
 480
 481 #include "gt-tree-profile.h"