/* Calculate branch probabilities, and basic block execution counts. Copyright (C) 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. Contributed by James E. Wilson, UC Berkeley/Cygnus Support; based on some ideas from Dain Samples of UC Berkeley. Further mangling by Bob Manson, Cygnus Support. Converted to use trees by Dale Johannesen, Apple Computer. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Generate basic block profile instrumentation and auxiliary files. Profile generation is optimized, so that not all arcs in the basic block graph need instrumenting. First, the BB graph is closed with one entry (function start), and one exit (function exit). Any ABNORMAL_EDGE cannot be instrumented (because there is no control path to place the code). We close the graph by inserting fake EDGE_FAKE edges to the EXIT_BLOCK, from the sources of abnormal edges that do not go to the exit_block. We ignore such abnormal edges. Naturally these fake edges are never directly traversed, and so *cannot* be directly instrumented. Some other graph massaging is done. To optimize the instrumentation we generate the BB minimal span tree, only edges that are not on the span tree (plus the entry point) need instrumenting. From that information all other edge counts can be deduced. By construction all fake edges must be on the spanning tree. We also attempt to place EDGE_CRITICAL edges on the spanning tree. The auxiliary file generated is <dumpbase>.bbg. The format is described in full in gcov-io.h. */ /* ??? Register allocation should use basic block execution counts to give preference to the most commonly executed blocks. */ /* ??? Should calculate branch probabilities before instrumenting code, since then we can use arc counts to help decide which arcs to instrument. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "rtl.h" #include "flags.h" #include "output.h" #include "regs.h" #include "expr.h" #include "function.h" #include "toplev.h" #include "coverage.h" #include "tree.h" #include "tree-flow.h" #include "tree-dump.h" #include "tree-pass.h" #include "timevar.h" #include "value-prof.h" /* Do initialization work for the edge profiler. */ static void tree_init_edge_profiler (void) { } /* Output instructions as GIMPLE trees to increment the edge execution count, and insert them on E. We rely on bsi_insert_on_edge to preserve the order. */ static void tree_gen_edge_profiler (int edgeno, edge e) { tree tmp1 = create_tmp_var (GCOV_TYPE_NODE, "PROF"); tree tmp2 = create_tmp_var (GCOV_TYPE_NODE, "PROF"); tree ref = tree_coverage_counter_ref (GCOV_COUNTER_ARCS, edgeno); tree stmt1 = build (MODIFY_EXPR, GCOV_TYPE_NODE, tmp1, ref); tree stmt2 = build (MODIFY_EXPR, GCOV_TYPE_NODE, tmp2, build (PLUS_EXPR, GCOV_TYPE_NODE, tmp1, integer_one_node)); tree stmt3 = build (MODIFY_EXPR, GCOV_TYPE_NODE, ref, tmp2); bsi_insert_on_edge (e, stmt1); bsi_insert_on_edge (e, stmt2); bsi_insert_on_edge (e, stmt3); } /* Output instructions as GIMPLE trees to increment the interval histogram counter. VALUE is the expression whose value is profiled. TAG is the tag of the section for counters, BASE is offset of the counter position. */ static void tree_gen_interval_profiler (histogram_value value ATTRIBUTE_UNUSED, unsigned tag ATTRIBUTE_UNUSED, unsigned base ATTRIBUTE_UNUSED) { /* FIXME implement this. */ #ifdef ENABLE_CHECKING internal_error ("unimplemented functionality"); #endif gcc_unreachable (); } /* Output instructions as GIMPLE trees to increment the power of two histogram counter. VALUE is the expression whose value is profiled. TAG is the tag of the section for counters, BASE is offset of the counter position. */ static void tree_gen_pow2_profiler (histogram_value value ATTRIBUTE_UNUSED, unsigned tag ATTRIBUTE_UNUSED, unsigned base ATTRIBUTE_UNUSED) { /* FIXME implement this. */ #ifdef ENABLE_CHECKING internal_error ("unimplemented functionality"); #endif gcc_unreachable (); } /* Output instructions as GIMPLE trees for code to find the most common value. VALUE is the expression whose value is profiled. TAG is the tag of the section for counters, BASE is offset of the counter position. */ static void tree_gen_one_value_profiler (histogram_value value ATTRIBUTE_UNUSED, unsigned tag ATTRIBUTE_UNUSED, unsigned base ATTRIBUTE_UNUSED) { /* FIXME implement this. */ #ifdef ENABLE_CHECKING internal_error ("unimplemented functionality"); #endif gcc_unreachable (); } /* Output instructions as GIMPLE trees for code to find the most common value of a difference between two evaluations of an expression. VALUE is the expression whose value is profiled. TAG is the tag of the section for counters, BASE is offset of the counter position. */ static void tree_gen_const_delta_profiler (histogram_value value ATTRIBUTE_UNUSED, unsigned tag ATTRIBUTE_UNUSED, unsigned base ATTRIBUTE_UNUSED) { /* FIXME implement this. */ #ifdef ENABLE_CHECKING internal_error ("unimplemented functionality"); #endif gcc_unreachable (); } /* Return 1 if tree-based profiling is in effect, else 0. If it is, set up hooks for tree-based profiling. Gate for pass_tree_profile. */ static bool do_tree_profiling (void) { if (flag_tree_based_profiling && (profile_arc_flag || flag_test_coverage || flag_branch_probabilities)) { tree_register_profile_hooks (); tree_register_value_prof_hooks (); return true; } return false; } /* Return the file on which profile dump output goes, if any. */ static FILE *tree_profile_dump_file (void) { return dump_file; } struct tree_opt_pass pass_tree_profile = { "tree_profile", /* name */ do_tree_profiling, /* gate */ branch_prob, /* execute */ NULL, /* sub */ NULL, /* next */ 0, /* static_pass_number */ TV_BRANCH_PROB, /* tv_id */ PROP_gimple_leh | PROP_cfg, /* properties_required */ PROP_gimple_leh | PROP_cfg, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_verify_stmts, /* todo_flags_finish */ 0 /* letter */ }; struct profile_hooks tree_profile_hooks = { tree_init_edge_profiler, /* init_edge_profiler */ tree_gen_edge_profiler, /* gen_edge_profiler */ tree_gen_interval_profiler, /* gen_interval_profiler */ tree_gen_pow2_profiler, /* gen_pow2_profiler */ tree_gen_one_value_profiler, /* gen_one_value_profiler */ tree_gen_const_delta_profiler,/* gen_const_delta_profiler */ tree_profile_dump_file /* profile_dump_file */ };