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Diffstat (limited to 'gcc/tree-profile.c')
| -rw-r--r-- | gcc/tree-profile.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/gcc/tree-profile.c b/gcc/tree-profile.c new file mode 100644 index 00000000000..c1498ea8d5c --- /dev/null +++ b/gcc/tree-profile.c @@ -0,0 +1,188 @@ +/* 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" + + +/* 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 (struct histogram_value *value ATTRIBUTE_UNUSED, + unsigned tag ATTRIBUTE_UNUSED, + unsigned base ATTRIBUTE_UNUSED) +{ + /* FIXME implement this. */ + abort (); +} + +/* 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 (struct histogram_value *value ATTRIBUTE_UNUSED, + unsigned tag ATTRIBUTE_UNUSED, + unsigned base ATTRIBUTE_UNUSED) +{ + /* FIXME implement this. */ + abort (); +} + +/* 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 (struct histogram_value *value ATTRIBUTE_UNUSED, + unsigned tag ATTRIBUTE_UNUSED, + unsigned base ATTRIBUTE_UNUSED) +{ + /* FIXME implement this. */ + abort (); +} + +/* 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 (struct histogram_value *value ATTRIBUTE_UNUSED, + unsigned tag ATTRIBUTE_UNUSED, + unsigned base ATTRIBUTE_UNUSED) +{ + /* FIXME implement this. */ + abort (); +} + +/* 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) + { + tree_register_profile_hooks (); + tree_register_value_prof_hooks (); + } + return flag_tree_based_profiling; +} + +/* 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 */ +}; + +struct profile_hooks tree_profile_hooks = +{ + 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 */ +}; |