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 (unshare_expr (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_ptr = tree_coverage_counter_addr (tag, base);
 235   tree call, val;
 236
 237   ref_ptr = force_gimple_operand_bsi (&bsi, ref_ptr,
 238                                       true, NULL_TREE, true, BSI_SAME_STMT);
 239   val = prepare_instrumented_value (&bsi, value);
 240   call = build_call_expr (tree_pow2_profiler_fn, 2, ref_ptr, val);
 241   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 242 }
 243
 244 /* Output instructions as GIMPLE trees for code to find the most common value.
 245    VALUE is the expression whose value is profiled.  TAG is the tag of the
 246    section for counters, BASE is offset of the counter position.  */
 247
 248 static void
 249 tree_gen_one_value_profiler (histogram_value value, unsigned tag, unsigned base)
 250 {
 251   tree stmt = value->hvalue.stmt;
 252   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 253   tree ref_ptr = tree_coverage_counter_addr (tag, base);
 254   tree call, val;
 255
 256   ref_ptr = force_gimple_operand_bsi (&bsi, ref_ptr,
 257                                       true, NULL_TREE, true, BSI_SAME_STMT);
 258   val = prepare_instrumented_value (&bsi, value);
 259   call = build_call_expr (tree_one_value_profiler_fn, 2, ref_ptr, val);
 260   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 261 }
 262
 263
 264 /* Output instructions as GIMPLE trees for code to find the most
 265    common called function in indirect call.
 266    VALUE is the call expression whose indirect callee is profiled.
 267    TAG is the tag of the section for counters, BASE is offset of the
 268    counter position.  */
 269
 270 static void
 271 tree_gen_ic_profiler (histogram_value value, unsigned tag, unsigned base)
 272 {
 273   tree tmp1, stmt1, stmt2, stmt3;
 274   tree stmt = value->hvalue.stmt;
 275   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 276   tree ref_ptr = tree_coverage_counter_addr (tag, base);
 277
 278   ref_ptr = force_gimple_operand_bsi (&bsi, ref_ptr,
 279                                       true, NULL_TREE, true, BSI_SAME_STMT);
 280
 281   /* Insert code:
 282
 283     __gcov_indirect_call_counters = get_relevant_counter_ptr ();
 284     __gcov_indirect_call_callee = (void *) indirect call argument;
 285    */
 286
 287   tmp1 = create_tmp_var (ptr_void, "PROF");
 288   stmt1 = build_gimple_modify_stmt (ic_gcov_type_ptr_var, ref_ptr);
 289   stmt2 = build_gimple_modify_stmt (tmp1, unshare_expr (value->hvalue.value));
 290   stmt3 = build_gimple_modify_stmt (ic_void_ptr_var, tmp1);
 291
 292   bsi_insert_before (&bsi, stmt1, BSI_SAME_STMT);
 293   bsi_insert_before (&bsi, stmt2, BSI_SAME_STMT);
 294   bsi_insert_before (&bsi, stmt3, BSI_SAME_STMT);
 295 }
 296
 297
 298 /* Output instructions as GIMPLE trees for code to find the most
 299    common called function in indirect call. Insert instructions at the
 300    beginning of every possible called function.
 301   */
 302
 303 static void
 304 tree_gen_ic_func_profiler (void)
 305 {
 306   struct cgraph_node * c_node = cgraph_node (current_function_decl);
 307   block_stmt_iterator bsi;
 308   edge e;
 309   basic_block bb;
 310   edge_iterator ei;
 311   tree stmt1;
 312   tree tree_uid, cur_func;
 313
 314   if (flag_unit_at_a_time)
 315     {
 316       if (!c_node->needed)
 317         return;
 318     }
 319
 320   tree_init_edge_profiler ();
 321
 322   FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
 323     {
 324       bb = split_edge (e);
 325       bsi = bsi_start (bb);
 326       cur_func = force_gimple_operand_bsi (&bsi,
 327                                            build_addr (current_function_decl,
 328                                                        current_function_decl),
 329                                            true, NULL_TREE,
 330                                            true, BSI_SAME_STMT);
 331       tree_uid = build_int_cst (gcov_type_node, c_node->pid);
 332       stmt1 = build_call_expr (tree_indirect_call_profiler_fn, 4,
 333                                ic_gcov_type_ptr_var,
 334                                tree_uid,
 335                                cur_func,
 336                                ic_void_ptr_var);
 337       bsi_insert_after (&bsi, stmt1, BSI_NEW_STMT);
 338     }
 339 }
 340
 341 /* Output instructions as GIMPLE trees for code to find the most common value
 342    of a difference between two evaluations of an expression.
 343    VALUE is the expression whose value is profiled.  TAG is the tag of the
 344    section for counters, BASE is offset of the counter position.  */
 345
 346 static void
 347 tree_gen_const_delta_profiler (histogram_value value ATTRIBUTE_UNUSED,
 348                                 unsigned tag ATTRIBUTE_UNUSED,
 349                                 unsigned base ATTRIBUTE_UNUSED)
 350 {
 351   /* FIXME implement this.  */
 352 #ifdef ENABLE_CHECKING
 353   internal_error ("unimplemented functionality");
 354 #endif
 355   gcc_unreachable ();
 356 }
 357
 358 /* Output instructions as GIMPLE trees to increment the average histogram
 359    counter.  VALUE is the expression whose value is profiled.  TAG is the
 360    tag of the section for counters, BASE is offset of the counter position.  */
 361
 362 static void
 363 tree_gen_average_profiler (histogram_value value, unsigned tag, unsigned base)
 364 {
 365   tree stmt = value->hvalue.stmt;
 366   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 367   tree ref_ptr = tree_coverage_counter_addr (tag, base);
 368   tree call, val;
 369
 370   ref_ptr = force_gimple_operand_bsi (&bsi, ref_ptr,
 371                                       true, NULL_TREE,
 372                                       true, BSI_SAME_STMT);
 373   val = prepare_instrumented_value (&bsi, value);
 374   call = build_call_expr (tree_average_profiler_fn, 2, ref_ptr, val);
 375   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 376 }
 377
 378 /* Output instructions as GIMPLE trees to increment the ior histogram
 379    counter.  VALUE is the expression whose value is profiled.  TAG is the
 380    tag of the section for counters, BASE is offset of the counter position.  */
 381
 382 static void
 383 tree_gen_ior_profiler (histogram_value value, unsigned tag, unsigned base)
 384 {
 385   tree stmt = value->hvalue.stmt;
 386   block_stmt_iterator bsi = bsi_for_stmt (stmt);
 387   tree ref_ptr = tree_coverage_counter_addr (tag, base);
 388   tree call, val;
 389
 390   ref_ptr = force_gimple_operand_bsi (&bsi, ref_ptr,
 391                                       true, NULL_TREE, true, BSI_SAME_STMT);
 392   val = prepare_instrumented_value (&bsi, value);
 393   call = build_call_expr (tree_ior_profiler_fn, 2, ref_ptr, val);
 394   bsi_insert_before (&bsi, call, BSI_SAME_STMT);
 395 }
 396
 397 /* Return 1 if tree-based profiling is in effect, else 0.
 398    If it is, set up hooks for tree-based profiling.
 399    Gate for pass_tree_profile.  */
 400
 401 static bool
 402 do_tree_profiling (void)
 403 {
 404   if (profile_arc_flag || flag_test_coverage || flag_branch_probabilities)
 405     {
 406       tree_register_profile_hooks ();
 407       tree_register_value_prof_hooks ();
 408       return true;
 409     }
 410   return false;
 411 }
 412
 413 static unsigned int
 414 tree_profiling (void)
 415 {
 416   /* Don't profile functions produced at destruction time, particularly
 417      the gcov datastructure initializer.  Don't profile if it has been
 418      already instrumented either (when OpenMP expansion creates
 419      child function from already instrumented body).  */
 420   if (cgraph_state == CGRAPH_STATE_FINISHED
 421       || cfun->after_tree_profile)
 422     return 0;
 423
 424   /* Re-set global shared temporary variable for edge-counters.  */
 425   gcov_type_tmp_var = NULL_TREE;
 426
 427   branch_prob ();
 428
 429   if (! flag_branch_probabilities
 430       && flag_profile_values)
 431     tree_gen_ic_func_profiler ();
 432
 433   if (flag_branch_probabilities
 434       && flag_profile_values
 435       && flag_value_profile_transformations)
 436     value_profile_transformations ();
 437   /* The above could hose dominator info.  Currently there is
 438      none coming in, this is a safety valve.  It should be
 439      easy to adjust it, if and when there is some.  */
 440   free_dominance_info (CDI_DOMINATORS);
 441   free_dominance_info (CDI_POST_DOMINATORS);
 442   cfun->after_tree_profile = 1;
 443   return 0;
 444 }
 445
 446 struct gimple_opt_pass pass_tree_profile =
 447 {
 448  {
 449   GIMPLE_PASS,
 450   "tree_profile",                       /* name */
 451   do_tree_profiling,                    /* gate */
 452   tree_profiling,                       /* execute */
 453   NULL,                                 /* sub */
 454   NULL,                                 /* next */
 455   0,                                    /* static_pass_number */
 456   TV_BRANCH_PROB,                       /* tv_id */
 457   PROP_gimple_leh | PROP_cfg,           /* properties_required */
 458   PROP_gimple_leh | PROP_cfg,           /* properties_provided */
 459   0,                                    /* properties_destroyed */
 460   0,                                    /* todo_flags_start */
 461   TODO_verify_stmts | TODO_dump_func    /* todo_flags_finish */
 462  }
 463 };
 464
 465 struct profile_hooks tree_profile_hooks =
 466 {
 467   tree_init_edge_profiler,       /* init_edge_profiler */
 468   tree_gen_edge_profiler,        /* gen_edge_profiler */
 469   tree_gen_interval_profiler,    /* gen_interval_profiler */
 470   tree_gen_pow2_profiler,        /* gen_pow2_profiler */
 471   tree_gen_one_value_profiler,   /* gen_one_value_profiler */
 472   tree_gen_const_delta_profiler, /* gen_const_delta_profiler */
 473   tree_gen_ic_profiler,          /* gen_ic_profiler */
 474   tree_gen_average_profiler,     /* gen_average_profiler */
 475   tree_gen_ior_profiler          /* gen_ior_profiler */
 476 };
 477
 478 #include "gt-tree-profile.h"