1565 lines
45 KiB
C
1565 lines
45 KiB
C
/* Calculate branch probabilities, and basic block execution counts.
|
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Copyright (C) 1990-2013 Free Software Foundation, Inc.
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Contributed by James E. Wilson, UC Berkeley/Cygnus Support;
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based on some ideas from Dain Samples of UC Berkeley.
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Further mangling by Bob Manson, Cygnus Support.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
|
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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/* Generate basic block profile instrumentation and auxiliary files.
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Profile generation is optimized, so that not all arcs in the basic
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block graph need instrumenting. First, the BB graph is closed with
|
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one entry (function start), and one exit (function exit). Any
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ABNORMAL_EDGE cannot be instrumented (because there is no control
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path to place the code). We close the graph by inserting fake
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EDGE_FAKE edges to the EXIT_BLOCK, from the sources of abnormal
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edges that do not go to the exit_block. We ignore such abnormal
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edges. Naturally these fake edges are never directly traversed,
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and so *cannot* be directly instrumented. Some other graph
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massaging is done. To optimize the instrumentation we generate the
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BB minimal span tree, only edges that are not on the span tree
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(plus the entry point) need instrumenting. From that information
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all other edge counts can be deduced. By construction all fake
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edges must be on the spanning tree. We also attempt to place
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EDGE_CRITICAL edges on the spanning tree.
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The auxiliary files generated are <dumpbase>.gcno (at compile time)
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and <dumpbase>.gcda (at run time). The format is
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described in full in gcov-io.h. */
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/* ??? Register allocation should use basic block execution counts to
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give preference to the most commonly executed blocks. */
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/* ??? Should calculate branch probabilities before instrumenting code, since
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then we can use arc counts to help decide which arcs to instrument. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "rtl.h"
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#include "flags.h"
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#include "regs.h"
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#include "expr.h"
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#include "function.h"
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#include "basic-block.h"
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#include "diagnostic-core.h"
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#include "coverage.h"
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#include "value-prof.h"
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#include "tree.h"
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#include "tree-flow.h"
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#include "cfgloop.h"
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#include "dumpfile.h"
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#include "profile.h"
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struct bb_info {
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unsigned int count_valid : 1;
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/* Number of successor and predecessor edges. */
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gcov_type succ_count;
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gcov_type pred_count;
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};
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#define BB_INFO(b) ((struct bb_info *) (b)->aux)
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/* Counter summary from the last set of coverage counts read. */
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const struct gcov_ctr_summary *profile_info;
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/* Number of data points in the working set summary array. Using 128
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provides information for at least every 1% increment of the total
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profile size. The last entry is hardwired to 99.9% of the total. */
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#define NUM_GCOV_WORKING_SETS 128
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/* Counter working set information computed from the current counter
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summary. Not initialized unless profile_info summary is non-NULL. */
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static gcov_working_set_t gcov_working_sets[NUM_GCOV_WORKING_SETS];
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/* Collect statistics on the performance of this pass for the entire source
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file. */
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static int total_num_blocks;
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static int total_num_edges;
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static int total_num_edges_ignored;
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static int total_num_edges_instrumented;
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static int total_num_blocks_created;
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static int total_num_passes;
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static int total_num_times_called;
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static int total_hist_br_prob[20];
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static int total_num_branches;
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/* Forward declarations. */
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static void find_spanning_tree (struct edge_list *);
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/* Add edge instrumentation code to the entire insn chain.
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F is the first insn of the chain.
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NUM_BLOCKS is the number of basic blocks found in F. */
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static unsigned
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instrument_edges (struct edge_list *el)
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{
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unsigned num_instr_edges = 0;
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int num_edges = NUM_EDGES (el);
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basic_block bb;
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FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
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{
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edge e;
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edge_iterator ei;
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FOR_EACH_EDGE (e, ei, bb->succs)
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{
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struct edge_info *inf = EDGE_INFO (e);
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if (!inf->ignore && !inf->on_tree)
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{
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gcc_assert (!(e->flags & EDGE_ABNORMAL));
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if (dump_file)
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fprintf (dump_file, "Edge %d to %d instrumented%s\n",
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e->src->index, e->dest->index,
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EDGE_CRITICAL_P (e) ? " (and split)" : "");
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gimple_gen_edge_profiler (num_instr_edges++, e);
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}
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}
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}
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total_num_blocks_created += num_edges;
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if (dump_file)
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fprintf (dump_file, "%d edges instrumented\n", num_instr_edges);
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return num_instr_edges;
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}
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/* Add code to measure histograms for values in list VALUES. */
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static void
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instrument_values (histogram_values values)
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{
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unsigned i;
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/* Emit code to generate the histograms before the insns. */
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for (i = 0; i < values.length (); i++)
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{
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histogram_value hist = values[i];
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unsigned t = COUNTER_FOR_HIST_TYPE (hist->type);
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if (!coverage_counter_alloc (t, hist->n_counters))
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continue;
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switch (hist->type)
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{
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case HIST_TYPE_INTERVAL:
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gimple_gen_interval_profiler (hist, t, 0);
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break;
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case HIST_TYPE_POW2:
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gimple_gen_pow2_profiler (hist, t, 0);
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break;
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case HIST_TYPE_SINGLE_VALUE:
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gimple_gen_one_value_profiler (hist, t, 0);
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break;
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case HIST_TYPE_CONST_DELTA:
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gimple_gen_const_delta_profiler (hist, t, 0);
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break;
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case HIST_TYPE_INDIR_CALL:
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gimple_gen_ic_profiler (hist, t, 0);
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break;
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case HIST_TYPE_AVERAGE:
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gimple_gen_average_profiler (hist, t, 0);
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break;
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case HIST_TYPE_IOR:
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gimple_gen_ior_profiler (hist, t, 0);
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break;
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default:
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gcc_unreachable ();
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}
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}
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}
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/* Compute the working set information from the counter histogram in
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the profile summary. This is an array of information corresponding to a
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range of percentages of the total execution count (sum_all), and includes
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the number of counters required to cover that working set percentage and
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the minimum counter value in that working set. */
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void
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compute_working_sets (void)
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{
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gcov_type working_set_cum_values[NUM_GCOV_WORKING_SETS];
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gcov_type ws_cum_hotness_incr;
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gcov_type cum, tmp_cum;
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const gcov_bucket_type *histo_bucket;
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unsigned ws_ix, c_num, count, pctinc, pct;
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int h_ix;
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gcov_working_set_t *ws_info;
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if (!profile_info)
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return;
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/* Compute the amount of sum_all that the cumulative hotness grows
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by in each successive working set entry, which depends on the
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number of working set entries. */
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ws_cum_hotness_incr = profile_info->sum_all / NUM_GCOV_WORKING_SETS;
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/* Next fill in an array of the cumulative hotness values corresponding
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to each working set summary entry we are going to compute below.
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Skip 0% statistics, which can be extrapolated from the
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rest of the summary data. */
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cum = ws_cum_hotness_incr;
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for (ws_ix = 0; ws_ix < NUM_GCOV_WORKING_SETS;
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ws_ix++, cum += ws_cum_hotness_incr)
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working_set_cum_values[ws_ix] = cum;
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/* The last summary entry is reserved for (roughly) 99.9% of the
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working set. Divide by 1024 so it becomes a shift, which gives
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almost exactly 99.9%. */
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working_set_cum_values[NUM_GCOV_WORKING_SETS-1]
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= profile_info->sum_all - profile_info->sum_all/1024;
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/* Next, walk through the histogram in decending order of hotness
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and compute the statistics for the working set summary array.
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As histogram entries are accumulated, we check to see which
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working set entries have had their expected cum_value reached
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and fill them in, walking the working set entries in increasing
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size of cum_value. */
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ws_ix = 0; /* The current entry into the working set array. */
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cum = 0; /* The current accumulated counter sum. */
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count = 0; /* The current accumulated count of block counters. */
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for (h_ix = GCOV_HISTOGRAM_SIZE - 1;
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h_ix >= 0 && ws_ix < NUM_GCOV_WORKING_SETS; h_ix--)
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{
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histo_bucket = &profile_info->histogram[h_ix];
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/* If we haven't reached the required cumulative counter value for
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the current working set percentage, simply accumulate this histogram
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entry into the running sums and continue to the next histogram
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entry. */
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if (cum + histo_bucket->cum_value < working_set_cum_values[ws_ix])
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{
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cum += histo_bucket->cum_value;
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count += histo_bucket->num_counters;
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continue;
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}
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/* If adding the current histogram entry's cumulative counter value
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causes us to exceed the current working set size, then estimate
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how many of this histogram entry's counter values are required to
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reach the working set size, and fill in working set entries
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as we reach their expected cumulative value. */
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for (c_num = 0, tmp_cum = cum;
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c_num < histo_bucket->num_counters && ws_ix < NUM_GCOV_WORKING_SETS;
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c_num++)
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{
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count++;
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/* If we haven't reached the last histogram entry counter, add
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in the minimum value again. This will underestimate the
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cumulative sum so far, because many of the counter values in this
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entry may have been larger than the minimum. We could add in the
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average value every time, but that would require an expensive
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divide operation. */
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if (c_num + 1 < histo_bucket->num_counters)
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tmp_cum += histo_bucket->min_value;
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/* If we have reached the last histogram entry counter, then add
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in the entire cumulative value. */
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else
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tmp_cum = cum + histo_bucket->cum_value;
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/* Next walk through successive working set entries and fill in
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the statistics for any whose size we have reached by accumulating
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this histogram counter. */
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while (ws_ix < NUM_GCOV_WORKING_SETS
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&& tmp_cum >= working_set_cum_values[ws_ix])
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{
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gcov_working_sets[ws_ix].num_counters = count;
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gcov_working_sets[ws_ix].min_counter
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= histo_bucket->min_value;
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ws_ix++;
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}
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}
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/* Finally, update the running cumulative value since we were
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using a temporary above. */
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cum += histo_bucket->cum_value;
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}
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gcc_assert (ws_ix == NUM_GCOV_WORKING_SETS);
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if (dump_file)
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{
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fprintf (dump_file, "Counter working sets:\n");
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/* Multiply the percentage by 100 to avoid float. */
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pctinc = 100 * 100 / NUM_GCOV_WORKING_SETS;
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for (ws_ix = 0, pct = pctinc; ws_ix < NUM_GCOV_WORKING_SETS;
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ws_ix++, pct += pctinc)
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{
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if (ws_ix == NUM_GCOV_WORKING_SETS - 1)
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pct = 9990;
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ws_info = &gcov_working_sets[ws_ix];
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/* Print out the percentage using int arithmatic to avoid float. */
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fprintf (dump_file, "\t\t%u.%02u%%: num counts=%u, min counter="
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HOST_WIDEST_INT_PRINT_DEC "\n",
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pct / 100, pct - (pct / 100 * 100),
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ws_info->num_counters,
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(HOST_WIDEST_INT)ws_info->min_counter);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Given a the desired percentage of the full profile (sum_all from the
|
||
summary), multiplied by 10 to avoid float in PCT_TIMES_10, returns
|
||
the corresponding working set information. If an exact match for
|
||
the percentage isn't found, the closest value is used. */
|
||
|
||
gcov_working_set_t *
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find_working_set (unsigned pct_times_10)
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{
|
||
unsigned i;
|
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if (!profile_info)
|
||
return NULL;
|
||
gcc_assert (pct_times_10 <= 1000);
|
||
if (pct_times_10 >= 999)
|
||
return &gcov_working_sets[NUM_GCOV_WORKING_SETS - 1];
|
||
i = pct_times_10 * NUM_GCOV_WORKING_SETS / 1000;
|
||
if (!i)
|
||
return &gcov_working_sets[0];
|
||
return &gcov_working_sets[i - 1];
|
||
}
|
||
|
||
/* Computes hybrid profile for all matching entries in da_file.
|
||
|
||
CFG_CHECKSUM is the precomputed checksum for the CFG. */
|
||
|
||
static gcov_type *
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get_exec_counts (unsigned cfg_checksum, unsigned lineno_checksum)
|
||
{
|
||
unsigned num_edges = 0;
|
||
basic_block bb;
|
||
gcov_type *counts;
|
||
|
||
/* Count the edges to be (possibly) instrumented. */
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
|
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num_edges++;
|
||
}
|
||
|
||
counts = get_coverage_counts (GCOV_COUNTER_ARCS, num_edges, cfg_checksum,
|
||
lineno_checksum, &profile_info);
|
||
if (!counts)
|
||
return NULL;
|
||
|
||
compute_working_sets();
|
||
|
||
if (dump_file && profile_info)
|
||
fprintf(dump_file, "Merged %u profiles with maximal count %u.\n",
|
||
profile_info->runs, (unsigned) profile_info->sum_max);
|
||
|
||
return counts;
|
||
}
|
||
|
||
|
||
static bool
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||
is_edge_inconsistent (vec<edge, va_gc> *edges)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
FOR_EACH_EDGE (e, ei, edges)
|
||
{
|
||
if (!EDGE_INFO (e)->ignore)
|
||
{
|
||
if (e->count < 0
|
||
&& (!(e->flags & EDGE_FAKE)
|
||
|| !block_ends_with_call_p (e->src)))
|
||
{
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file,
|
||
"Edge %i->%i is inconsistent, count"HOST_WIDEST_INT_PRINT_DEC,
|
||
e->src->index, e->dest->index, e->count);
|
||
dump_bb (dump_file, e->src, 0, TDF_DETAILS);
|
||
dump_bb (dump_file, e->dest, 0, TDF_DETAILS);
|
||
}
|
||
return true;
|
||
}
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
|
||
static void
|
||
correct_negative_edge_counts (void)
|
||
{
|
||
basic_block bb;
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
{
|
||
if (e->count < 0)
|
||
e->count = 0;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Check consistency.
|
||
Return true if inconsistency is found. */
|
||
static bool
|
||
is_inconsistent (void)
|
||
{
|
||
basic_block bb;
|
||
bool inconsistent = false;
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
inconsistent |= is_edge_inconsistent (bb->preds);
|
||
if (!dump_file && inconsistent)
|
||
return true;
|
||
inconsistent |= is_edge_inconsistent (bb->succs);
|
||
if (!dump_file && inconsistent)
|
||
return true;
|
||
if (bb->count < 0)
|
||
{
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "BB %i count is negative "
|
||
HOST_WIDEST_INT_PRINT_DEC,
|
||
bb->index,
|
||
bb->count);
|
||
dump_bb (dump_file, bb, 0, TDF_DETAILS);
|
||
}
|
||
inconsistent = true;
|
||
}
|
||
if (bb->count != sum_edge_counts (bb->preds))
|
||
{
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "BB %i count does not match sum of incoming edges "
|
||
HOST_WIDEST_INT_PRINT_DEC" should be " HOST_WIDEST_INT_PRINT_DEC,
|
||
bb->index,
|
||
bb->count,
|
||
sum_edge_counts (bb->preds));
|
||
dump_bb (dump_file, bb, 0, TDF_DETAILS);
|
||
}
|
||
inconsistent = true;
|
||
}
|
||
if (bb->count != sum_edge_counts (bb->succs) &&
|
||
! (find_edge (bb, EXIT_BLOCK_PTR) != NULL && block_ends_with_call_p (bb)))
|
||
{
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "BB %i count does not match sum of outgoing edges "
|
||
HOST_WIDEST_INT_PRINT_DEC" should be " HOST_WIDEST_INT_PRINT_DEC,
|
||
bb->index,
|
||
bb->count,
|
||
sum_edge_counts (bb->succs));
|
||
dump_bb (dump_file, bb, 0, TDF_DETAILS);
|
||
}
|
||
inconsistent = true;
|
||
}
|
||
if (!dump_file && inconsistent)
|
||
return true;
|
||
}
|
||
|
||
return inconsistent;
|
||
}
|
||
|
||
/* Set each basic block count to the sum of its outgoing edge counts */
|
||
static void
|
||
set_bb_counts (void)
|
||
{
|
||
basic_block bb;
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
bb->count = sum_edge_counts (bb->succs);
|
||
gcc_assert (bb->count >= 0);
|
||
}
|
||
}
|
||
|
||
/* Reads profile data and returns total number of edge counts read */
|
||
static int
|
||
read_profile_edge_counts (gcov_type *exec_counts)
|
||
{
|
||
basic_block bb;
|
||
int num_edges = 0;
|
||
int exec_counts_pos = 0;
|
||
/* For each edge not on the spanning tree, set its execution count from
|
||
the .da file. */
|
||
/* The first count in the .da file is the number of times that the function
|
||
was entered. This is the exec_count for block zero. */
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
|
||
{
|
||
num_edges++;
|
||
if (exec_counts)
|
||
{
|
||
e->count = exec_counts[exec_counts_pos++];
|
||
if (e->count > profile_info->sum_max)
|
||
{
|
||
if (flag_profile_correction)
|
||
{
|
||
static bool informed = 0;
|
||
if (!informed)
|
||
inform (input_location,
|
||
"corrupted profile info: edge count exceeds maximal count");
|
||
informed = 1;
|
||
}
|
||
else
|
||
error ("corrupted profile info: edge from %i to %i exceeds maximal count",
|
||
bb->index, e->dest->index);
|
||
}
|
||
}
|
||
else
|
||
e->count = 0;
|
||
|
||
EDGE_INFO (e)->count_valid = 1;
|
||
BB_INFO (bb)->succ_count--;
|
||
BB_INFO (e->dest)->pred_count--;
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "\nRead edge from %i to %i, count:",
|
||
bb->index, e->dest->index);
|
||
fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC,
|
||
(HOST_WIDEST_INT) e->count);
|
||
}
|
||
}
|
||
}
|
||
|
||
return num_edges;
|
||
}
|
||
|
||
#define OVERLAP_BASE 10000
|
||
|
||
/* Compare the static estimated profile to the actual profile, and
|
||
return the "degree of overlap" measure between them.
|
||
|
||
Degree of overlap is a number between 0 and OVERLAP_BASE. It is
|
||
the sum of each basic block's minimum relative weights between
|
||
two profiles. And overlap of OVERLAP_BASE means two profiles are
|
||
identical. */
|
||
|
||
static int
|
||
compute_frequency_overlap (void)
|
||
{
|
||
gcov_type count_total = 0, freq_total = 0;
|
||
int overlap = 0;
|
||
basic_block bb;
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
count_total += bb->count;
|
||
freq_total += bb->frequency;
|
||
}
|
||
|
||
if (count_total == 0 || freq_total == 0)
|
||
return 0;
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
overlap += MIN (bb->count * OVERLAP_BASE / count_total,
|
||
bb->frequency * OVERLAP_BASE / freq_total);
|
||
|
||
return overlap;
|
||
}
|
||
|
||
/* Compute the branch probabilities for the various branches.
|
||
Annotate them accordingly.
|
||
|
||
CFG_CHECKSUM is the precomputed checksum for the CFG. */
|
||
|
||
static void
|
||
compute_branch_probabilities (unsigned cfg_checksum, unsigned lineno_checksum)
|
||
{
|
||
basic_block bb;
|
||
int i;
|
||
int num_edges = 0;
|
||
int changes;
|
||
int passes;
|
||
int hist_br_prob[20];
|
||
int num_branches;
|
||
gcov_type *exec_counts = get_exec_counts (cfg_checksum, lineno_checksum);
|
||
int inconsistent = 0;
|
||
|
||
/* Very simple sanity checks so we catch bugs in our profiling code. */
|
||
if (!profile_info)
|
||
return;
|
||
if (profile_info->run_max * profile_info->runs < profile_info->sum_max)
|
||
{
|
||
error ("corrupted profile info: run_max * runs < sum_max");
|
||
exec_counts = NULL;
|
||
}
|
||
|
||
if (profile_info->sum_all < profile_info->sum_max)
|
||
{
|
||
error ("corrupted profile info: sum_all is smaller than sum_max");
|
||
exec_counts = NULL;
|
||
}
|
||
|
||
/* Attach extra info block to each bb. */
|
||
alloc_aux_for_blocks (sizeof (struct bb_info));
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (!EDGE_INFO (e)->ignore)
|
||
BB_INFO (bb)->succ_count++;
|
||
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
if (!EDGE_INFO (e)->ignore)
|
||
BB_INFO (bb)->pred_count++;
|
||
}
|
||
|
||
/* Avoid predicting entry on exit nodes. */
|
||
BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
|
||
BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
|
||
|
||
num_edges = read_profile_edge_counts (exec_counts);
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "\n%d edge counts read\n", num_edges);
|
||
|
||
/* For every block in the file,
|
||
- if every exit/entrance edge has a known count, then set the block count
|
||
- if the block count is known, and every exit/entrance edge but one has
|
||
a known execution count, then set the count of the remaining edge
|
||
|
||
As edge counts are set, decrement the succ/pred count, but don't delete
|
||
the edge, that way we can easily tell when all edges are known, or only
|
||
one edge is unknown. */
|
||
|
||
/* The order that the basic blocks are iterated through is important.
|
||
Since the code that finds spanning trees starts with block 0, low numbered
|
||
edges are put on the spanning tree in preference to high numbered edges.
|
||
Hence, most instrumented edges are at the end. Graph solving works much
|
||
faster if we propagate numbers from the end to the start.
|
||
|
||
This takes an average of slightly more than 3 passes. */
|
||
|
||
changes = 1;
|
||
passes = 0;
|
||
while (changes)
|
||
{
|
||
passes++;
|
||
changes = 0;
|
||
FOR_BB_BETWEEN (bb, EXIT_BLOCK_PTR, NULL, prev_bb)
|
||
{
|
||
struct bb_info *bi = BB_INFO (bb);
|
||
if (! bi->count_valid)
|
||
{
|
||
if (bi->succ_count == 0)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
gcov_type total = 0;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
total += e->count;
|
||
bb->count = total;
|
||
bi->count_valid = 1;
|
||
changes = 1;
|
||
}
|
||
else if (bi->pred_count == 0)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
gcov_type total = 0;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
total += e->count;
|
||
bb->count = total;
|
||
bi->count_valid = 1;
|
||
changes = 1;
|
||
}
|
||
}
|
||
if (bi->count_valid)
|
||
{
|
||
if (bi->succ_count == 1)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
gcov_type total = 0;
|
||
|
||
/* One of the counts will be invalid, but it is zero,
|
||
so adding it in also doesn't hurt. */
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
total += e->count;
|
||
|
||
/* Search for the invalid edge, and set its count. */
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
|
||
break;
|
||
|
||
/* Calculate count for remaining edge by conservation. */
|
||
total = bb->count - total;
|
||
|
||
gcc_assert (e);
|
||
EDGE_INFO (e)->count_valid = 1;
|
||
e->count = total;
|
||
bi->succ_count--;
|
||
|
||
BB_INFO (e->dest)->pred_count--;
|
||
changes = 1;
|
||
}
|
||
if (bi->pred_count == 1)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
gcov_type total = 0;
|
||
|
||
/* One of the counts will be invalid, but it is zero,
|
||
so adding it in also doesn't hurt. */
|
||
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
total += e->count;
|
||
|
||
/* Search for the invalid edge, and set its count. */
|
||
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
if (!EDGE_INFO (e)->count_valid && !EDGE_INFO (e)->ignore)
|
||
break;
|
||
|
||
/* Calculate count for remaining edge by conservation. */
|
||
total = bb->count - total + e->count;
|
||
|
||
gcc_assert (e);
|
||
EDGE_INFO (e)->count_valid = 1;
|
||
e->count = total;
|
||
bi->pred_count--;
|
||
|
||
BB_INFO (e->src)->succ_count--;
|
||
changes = 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
if (dump_file)
|
||
{
|
||
int overlap = compute_frequency_overlap ();
|
||
gimple_dump_cfg (dump_file, dump_flags);
|
||
fprintf (dump_file, "Static profile overlap: %d.%d%%\n",
|
||
overlap / (OVERLAP_BASE / 100),
|
||
overlap % (OVERLAP_BASE / 100));
|
||
}
|
||
|
||
total_num_passes += passes;
|
||
if (dump_file)
|
||
fprintf (dump_file, "Graph solving took %d passes.\n\n", passes);
|
||
|
||
/* If the graph has been correctly solved, every block will have a
|
||
succ and pred count of zero. */
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
gcc_assert (!BB_INFO (bb)->succ_count && !BB_INFO (bb)->pred_count);
|
||
}
|
||
|
||
/* Check for inconsistent basic block counts */
|
||
inconsistent = is_inconsistent ();
|
||
|
||
if (inconsistent)
|
||
{
|
||
if (flag_profile_correction)
|
||
{
|
||
/* Inconsistency detected. Make it flow-consistent. */
|
||
static int informed = 0;
|
||
if (informed == 0)
|
||
{
|
||
informed = 1;
|
||
inform (input_location, "correcting inconsistent profile data");
|
||
}
|
||
correct_negative_edge_counts ();
|
||
/* Set bb counts to the sum of the outgoing edge counts */
|
||
set_bb_counts ();
|
||
if (dump_file)
|
||
fprintf (dump_file, "\nCalling mcf_smooth_cfg\n");
|
||
mcf_smooth_cfg ();
|
||
}
|
||
else
|
||
error ("corrupted profile info: profile data is not flow-consistent");
|
||
}
|
||
|
||
/* For every edge, calculate its branch probability and add a reg_note
|
||
to the branch insn to indicate this. */
|
||
|
||
for (i = 0; i < 20; i++)
|
||
hist_br_prob[i] = 0;
|
||
num_branches = 0;
|
||
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
if (bb->count < 0)
|
||
{
|
||
error ("corrupted profile info: number of iterations for basic block %d thought to be %i",
|
||
bb->index, (int)bb->count);
|
||
bb->count = 0;
|
||
}
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
{
|
||
/* Function may return twice in the cased the called function is
|
||
setjmp or calls fork, but we can't represent this by extra
|
||
edge from the entry, since extra edge from the exit is
|
||
already present. We get negative frequency from the entry
|
||
point. */
|
||
if ((e->count < 0
|
||
&& e->dest == EXIT_BLOCK_PTR)
|
||
|| (e->count > bb->count
|
||
&& e->dest != EXIT_BLOCK_PTR))
|
||
{
|
||
if (block_ends_with_call_p (bb))
|
||
e->count = e->count < 0 ? 0 : bb->count;
|
||
}
|
||
if (e->count < 0 || e->count > bb->count)
|
||
{
|
||
error ("corrupted profile info: number of executions for edge %d-%d thought to be %i",
|
||
e->src->index, e->dest->index,
|
||
(int)e->count);
|
||
e->count = bb->count / 2;
|
||
}
|
||
}
|
||
if (bb->count)
|
||
{
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
e->probability = (e->count * REG_BR_PROB_BASE + bb->count / 2) / bb->count;
|
||
if (bb->index >= NUM_FIXED_BLOCKS
|
||
&& block_ends_with_condjump_p (bb)
|
||
&& EDGE_COUNT (bb->succs) >= 2)
|
||
{
|
||
int prob;
|
||
edge e;
|
||
int index;
|
||
|
||
/* Find the branch edge. It is possible that we do have fake
|
||
edges here. */
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (!(e->flags & (EDGE_FAKE | EDGE_FALLTHRU)))
|
||
break;
|
||
|
||
prob = e->probability;
|
||
index = prob * 20 / REG_BR_PROB_BASE;
|
||
|
||
if (index == 20)
|
||
index = 19;
|
||
hist_br_prob[index]++;
|
||
|
||
num_branches++;
|
||
}
|
||
}
|
||
/* As a last resort, distribute the probabilities evenly.
|
||
Use simple heuristics that if there are normal edges,
|
||
give all abnormals frequency of 0, otherwise distribute the
|
||
frequency over abnormals (this is the case of noreturn
|
||
calls). */
|
||
else if (profile_status == PROFILE_ABSENT)
|
||
{
|
||
int total = 0;
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
|
||
total ++;
|
||
if (total)
|
||
{
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
|
||
e->probability = REG_BR_PROB_BASE / total;
|
||
else
|
||
e->probability = 0;
|
||
}
|
||
else
|
||
{
|
||
total += EDGE_COUNT (bb->succs);
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
e->probability = REG_BR_PROB_BASE / total;
|
||
}
|
||
if (bb->index >= NUM_FIXED_BLOCKS
|
||
&& block_ends_with_condjump_p (bb)
|
||
&& EDGE_COUNT (bb->succs) >= 2)
|
||
num_branches++;
|
||
}
|
||
}
|
||
counts_to_freqs ();
|
||
profile_status = PROFILE_READ;
|
||
compute_function_frequency ();
|
||
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "%d branches\n", num_branches);
|
||
if (num_branches)
|
||
for (i = 0; i < 10; i++)
|
||
fprintf (dump_file, "%d%% branches in range %d-%d%%\n",
|
||
(hist_br_prob[i] + hist_br_prob[19-i]) * 100 / num_branches,
|
||
5 * i, 5 * i + 5);
|
||
|
||
total_num_branches += num_branches;
|
||
for (i = 0; i < 20; i++)
|
||
total_hist_br_prob[i] += hist_br_prob[i];
|
||
|
||
fputc ('\n', dump_file);
|
||
fputc ('\n', dump_file);
|
||
}
|
||
|
||
free_aux_for_blocks ();
|
||
}
|
||
|
||
/* Load value histograms values whose description is stored in VALUES array
|
||
from .gcda file.
|
||
|
||
CFG_CHECKSUM is the precomputed checksum for the CFG. */
|
||
|
||
static void
|
||
compute_value_histograms (histogram_values values, unsigned cfg_checksum,
|
||
unsigned lineno_checksum)
|
||
{
|
||
unsigned i, j, t, any;
|
||
unsigned n_histogram_counters[GCOV_N_VALUE_COUNTERS];
|
||
gcov_type *histogram_counts[GCOV_N_VALUE_COUNTERS];
|
||
gcov_type *act_count[GCOV_N_VALUE_COUNTERS];
|
||
gcov_type *aact_count;
|
||
|
||
for (t = 0; t < GCOV_N_VALUE_COUNTERS; t++)
|
||
n_histogram_counters[t] = 0;
|
||
|
||
for (i = 0; i < values.length (); i++)
|
||
{
|
||
histogram_value hist = values[i];
|
||
n_histogram_counters[(int) hist->type] += hist->n_counters;
|
||
}
|
||
|
||
any = 0;
|
||
for (t = 0; t < GCOV_N_VALUE_COUNTERS; t++)
|
||
{
|
||
if (!n_histogram_counters[t])
|
||
{
|
||
histogram_counts[t] = NULL;
|
||
continue;
|
||
}
|
||
|
||
histogram_counts[t] =
|
||
get_coverage_counts (COUNTER_FOR_HIST_TYPE (t),
|
||
n_histogram_counters[t], cfg_checksum,
|
||
lineno_checksum, NULL);
|
||
if (histogram_counts[t])
|
||
any = 1;
|
||
act_count[t] = histogram_counts[t];
|
||
}
|
||
if (!any)
|
||
return;
|
||
|
||
for (i = 0; i < values.length (); i++)
|
||
{
|
||
histogram_value hist = values[i];
|
||
gimple stmt = hist->hvalue.stmt;
|
||
|
||
t = (int) hist->type;
|
||
|
||
aact_count = act_count[t];
|
||
act_count[t] += hist->n_counters;
|
||
|
||
gimple_add_histogram_value (cfun, stmt, hist);
|
||
hist->hvalue.counters = XNEWVEC (gcov_type, hist->n_counters);
|
||
for (j = 0; j < hist->n_counters; j++)
|
||
hist->hvalue.counters[j] = aact_count[j];
|
||
}
|
||
|
||
for (t = 0; t < GCOV_N_VALUE_COUNTERS; t++)
|
||
free (histogram_counts[t]);
|
||
}
|
||
|
||
/* When passed NULL as file_name, initialize.
|
||
When passed something else, output the necessary commands to change
|
||
line to LINE and offset to FILE_NAME. */
|
||
static void
|
||
output_location (char const *file_name, int line,
|
||
gcov_position_t *offset, basic_block bb)
|
||
{
|
||
static char const *prev_file_name;
|
||
static int prev_line;
|
||
bool name_differs, line_differs;
|
||
|
||
if (!file_name)
|
||
{
|
||
prev_file_name = NULL;
|
||
prev_line = -1;
|
||
return;
|
||
}
|
||
|
||
name_differs = !prev_file_name || filename_cmp (file_name, prev_file_name);
|
||
line_differs = prev_line != line;
|
||
|
||
if (name_differs || line_differs)
|
||
{
|
||
if (!*offset)
|
||
{
|
||
*offset = gcov_write_tag (GCOV_TAG_LINES);
|
||
gcov_write_unsigned (bb->index);
|
||
name_differs = line_differs=true;
|
||
}
|
||
|
||
/* If this is a new source file, then output the
|
||
file's name to the .bb file. */
|
||
if (name_differs)
|
||
{
|
||
prev_file_name = file_name;
|
||
gcov_write_unsigned (0);
|
||
gcov_write_string (prev_file_name);
|
||
}
|
||
if (line_differs)
|
||
{
|
||
gcov_write_unsigned (line);
|
||
prev_line = line;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Instrument and/or analyze program behavior based on program the CFG.
|
||
|
||
This function creates a representation of the control flow graph (of
|
||
the function being compiled) that is suitable for the instrumentation
|
||
of edges and/or converting measured edge counts to counts on the
|
||
complete CFG.
|
||
|
||
When FLAG_PROFILE_ARCS is nonzero, this function instruments the edges in
|
||
the flow graph that are needed to reconstruct the dynamic behavior of the
|
||
flow graph. This data is written to the gcno file for gcov.
|
||
|
||
When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
|
||
information from the gcda file containing edge count information from
|
||
previous executions of the function being compiled. In this case, the
|
||
control flow graph is annotated with actual execution counts by
|
||
compute_branch_probabilities().
|
||
|
||
Main entry point of this file. */
|
||
|
||
void
|
||
branch_prob (void)
|
||
{
|
||
basic_block bb;
|
||
unsigned i;
|
||
unsigned num_edges, ignored_edges;
|
||
unsigned num_instrumented;
|
||
struct edge_list *el;
|
||
histogram_values values = histogram_values();
|
||
unsigned cfg_checksum, lineno_checksum;
|
||
|
||
total_num_times_called++;
|
||
|
||
flow_call_edges_add (NULL);
|
||
add_noreturn_fake_exit_edges ();
|
||
|
||
/* We can't handle cyclic regions constructed using abnormal edges.
|
||
To avoid these we replace every source of abnormal edge by a fake
|
||
edge from entry node and every destination by fake edge to exit.
|
||
This keeps graph acyclic and our calculation exact for all normal
|
||
edges except for exit and entrance ones.
|
||
|
||
We also add fake exit edges for each call and asm statement in the
|
||
basic, since it may not return. */
|
||
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
int need_exit_edge = 0, need_entry_edge = 0;
|
||
int have_exit_edge = 0, have_entry_edge = 0;
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
/* Functions returning multiple times are not handled by extra edges.
|
||
Instead we simply allow negative counts on edges from exit to the
|
||
block past call and corresponding probabilities. We can't go
|
||
with the extra edges because that would result in flowgraph that
|
||
needs to have fake edges outside the spanning tree. */
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
{
|
||
gimple_stmt_iterator gsi;
|
||
gimple last = NULL;
|
||
|
||
/* It may happen that there are compiler generated statements
|
||
without a locus at all. Go through the basic block from the
|
||
last to the first statement looking for a locus. */
|
||
for (gsi = gsi_last_nondebug_bb (bb);
|
||
!gsi_end_p (gsi);
|
||
gsi_prev_nondebug (&gsi))
|
||
{
|
||
last = gsi_stmt (gsi);
|
||
if (gimple_has_location (last))
|
||
break;
|
||
}
|
||
|
||
/* Edge with goto locus might get wrong coverage info unless
|
||
it is the only edge out of BB.
|
||
Don't do that when the locuses match, so
|
||
if (blah) goto something;
|
||
is not computed twice. */
|
||
if (last
|
||
&& gimple_has_location (last)
|
||
&& LOCATION_LOCUS (e->goto_locus) != UNKNOWN_LOCATION
|
||
&& !single_succ_p (bb)
|
||
&& (LOCATION_FILE (e->goto_locus)
|
||
!= LOCATION_FILE (gimple_location (last))
|
||
|| (LOCATION_LINE (e->goto_locus)
|
||
!= LOCATION_LINE (gimple_location (last)))))
|
||
{
|
||
basic_block new_bb = split_edge (e);
|
||
edge ne = single_succ_edge (new_bb);
|
||
ne->goto_locus = e->goto_locus;
|
||
}
|
||
if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
|
||
&& e->dest != EXIT_BLOCK_PTR)
|
||
need_exit_edge = 1;
|
||
if (e->dest == EXIT_BLOCK_PTR)
|
||
have_exit_edge = 1;
|
||
}
|
||
FOR_EACH_EDGE (e, ei, bb->preds)
|
||
{
|
||
if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
|
||
&& e->src != ENTRY_BLOCK_PTR)
|
||
need_entry_edge = 1;
|
||
if (e->src == ENTRY_BLOCK_PTR)
|
||
have_entry_edge = 1;
|
||
}
|
||
|
||
if (need_exit_edge && !have_exit_edge)
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Adding fake exit edge to bb %i\n",
|
||
bb->index);
|
||
make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
|
||
}
|
||
if (need_entry_edge && !have_entry_edge)
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Adding fake entry edge to bb %i\n",
|
||
bb->index);
|
||
make_edge (ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
|
||
/* Avoid bbs that have both fake entry edge and also some
|
||
exit edge. One of those edges wouldn't be added to the
|
||
spanning tree, but we can't instrument any of them. */
|
||
if (have_exit_edge || need_exit_edge)
|
||
{
|
||
gimple_stmt_iterator gsi;
|
||
gimple first;
|
||
tree fndecl;
|
||
|
||
gsi = gsi_after_labels (bb);
|
||
gcc_checking_assert (!gsi_end_p (gsi));
|
||
first = gsi_stmt (gsi);
|
||
if (is_gimple_debug (first))
|
||
{
|
||
gsi_next_nondebug (&gsi);
|
||
gcc_checking_assert (!gsi_end_p (gsi));
|
||
first = gsi_stmt (gsi);
|
||
}
|
||
/* Don't split the bbs containing __builtin_setjmp_receiver
|
||
or __builtin_setjmp_dispatcher calls. These are very
|
||
special and don't expect anything to be inserted before
|
||
them. */
|
||
if (!is_gimple_call (first)
|
||
|| (fndecl = gimple_call_fndecl (first)) == NULL
|
||
|| DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL
|
||
|| (DECL_FUNCTION_CODE (fndecl) != BUILT_IN_SETJMP_RECEIVER
|
||
&& (DECL_FUNCTION_CODE (fndecl)
|
||
!= BUILT_IN_SETJMP_DISPATCHER)))
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Splitting bb %i after labels\n",
|
||
bb->index);
|
||
split_block_after_labels (bb);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
el = create_edge_list ();
|
||
num_edges = NUM_EDGES (el);
|
||
alloc_aux_for_edges (sizeof (struct edge_info));
|
||
|
||
/* The basic blocks are expected to be numbered sequentially. */
|
||
compact_blocks ();
|
||
|
||
ignored_edges = 0;
|
||
for (i = 0 ; i < num_edges ; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
e->count = 0;
|
||
|
||
/* Mark edges we've replaced by fake edges above as ignored. */
|
||
if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL))
|
||
&& e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR)
|
||
{
|
||
EDGE_INFO (e)->ignore = 1;
|
||
ignored_edges++;
|
||
}
|
||
}
|
||
|
||
/* Create spanning tree from basic block graph, mark each edge that is
|
||
on the spanning tree. We insert as many abnormal and critical edges
|
||
as possible to minimize number of edge splits necessary. */
|
||
|
||
find_spanning_tree (el);
|
||
|
||
/* Fake edges that are not on the tree will not be instrumented, so
|
||
mark them ignored. */
|
||
for (num_instrumented = i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
struct edge_info *inf = EDGE_INFO (e);
|
||
|
||
if (inf->ignore || inf->on_tree)
|
||
/*NOP*/;
|
||
else if (e->flags & EDGE_FAKE)
|
||
{
|
||
inf->ignore = 1;
|
||
ignored_edges++;
|
||
}
|
||
else
|
||
num_instrumented++;
|
||
}
|
||
|
||
total_num_blocks += n_basic_blocks;
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d basic blocks\n", n_basic_blocks);
|
||
|
||
total_num_edges += num_edges;
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d edges\n", num_edges);
|
||
|
||
total_num_edges_ignored += ignored_edges;
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d ignored edges\n", ignored_edges);
|
||
|
||
total_num_edges_instrumented += num_instrumented;
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d instrumentation edges\n", num_instrumented);
|
||
|
||
/* Compute two different checksums. Note that we want to compute
|
||
the checksum in only once place, since it depends on the shape
|
||
of the control flow which can change during
|
||
various transformations. */
|
||
cfg_checksum = coverage_compute_cfg_checksum ();
|
||
lineno_checksum = coverage_compute_lineno_checksum ();
|
||
|
||
/* Write the data from which gcov can reconstruct the basic block
|
||
graph and function line numbers (the gcno file). */
|
||
if (coverage_begin_function (lineno_checksum, cfg_checksum))
|
||
{
|
||
gcov_position_t offset;
|
||
|
||
/* Basic block flags */
|
||
offset = gcov_write_tag (GCOV_TAG_BLOCKS);
|
||
for (i = 0; i != (unsigned) (n_basic_blocks); i++)
|
||
gcov_write_unsigned (0);
|
||
gcov_write_length (offset);
|
||
|
||
/* Arcs */
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
|
||
{
|
||
edge e;
|
||
edge_iterator ei;
|
||
|
||
offset = gcov_write_tag (GCOV_TAG_ARCS);
|
||
gcov_write_unsigned (bb->index);
|
||
|
||
FOR_EACH_EDGE (e, ei, bb->succs)
|
||
{
|
||
struct edge_info *i = EDGE_INFO (e);
|
||
if (!i->ignore)
|
||
{
|
||
unsigned flag_bits = 0;
|
||
|
||
if (i->on_tree)
|
||
flag_bits |= GCOV_ARC_ON_TREE;
|
||
if (e->flags & EDGE_FAKE)
|
||
flag_bits |= GCOV_ARC_FAKE;
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
flag_bits |= GCOV_ARC_FALLTHROUGH;
|
||
/* On trees we don't have fallthru flags, but we can
|
||
recompute them from CFG shape. */
|
||
if (e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)
|
||
&& e->src->next_bb == e->dest)
|
||
flag_bits |= GCOV_ARC_FALLTHROUGH;
|
||
|
||
gcov_write_unsigned (e->dest->index);
|
||
gcov_write_unsigned (flag_bits);
|
||
}
|
||
}
|
||
|
||
gcov_write_length (offset);
|
||
}
|
||
|
||
/* Line numbers. */
|
||
/* Initialize the output. */
|
||
output_location (NULL, 0, NULL, NULL);
|
||
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
gimple_stmt_iterator gsi;
|
||
gcov_position_t offset = 0;
|
||
|
||
if (bb == ENTRY_BLOCK_PTR->next_bb)
|
||
{
|
||
expanded_location curr_location =
|
||
expand_location (DECL_SOURCE_LOCATION (current_function_decl));
|
||
output_location (curr_location.file, curr_location.line,
|
||
&offset, bb);
|
||
}
|
||
|
||
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
||
{
|
||
gimple stmt = gsi_stmt (gsi);
|
||
if (gimple_has_location (stmt))
|
||
output_location (gimple_filename (stmt), gimple_lineno (stmt),
|
||
&offset, bb);
|
||
}
|
||
|
||
/* Notice GOTO expressions eliminated while constructing the CFG. */
|
||
if (single_succ_p (bb)
|
||
&& LOCATION_LOCUS (single_succ_edge (bb)->goto_locus)
|
||
!= UNKNOWN_LOCATION)
|
||
{
|
||
expanded_location curr_location
|
||
= expand_location (single_succ_edge (bb)->goto_locus);
|
||
output_location (curr_location.file, curr_location.line,
|
||
&offset, bb);
|
||
}
|
||
|
||
if (offset)
|
||
{
|
||
/* A file of NULL indicates the end of run. */
|
||
gcov_write_unsigned (0);
|
||
gcov_write_string (NULL);
|
||
gcov_write_length (offset);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (flag_profile_values)
|
||
gimple_find_values_to_profile (&values);
|
||
|
||
if (flag_branch_probabilities)
|
||
{
|
||
compute_branch_probabilities (cfg_checksum, lineno_checksum);
|
||
if (flag_profile_values)
|
||
compute_value_histograms (values, cfg_checksum, lineno_checksum);
|
||
}
|
||
|
||
remove_fake_edges ();
|
||
|
||
/* For each edge not on the spanning tree, add counting code. */
|
||
if (profile_arc_flag
|
||
&& coverage_counter_alloc (GCOV_COUNTER_ARCS, num_instrumented))
|
||
{
|
||
unsigned n_instrumented;
|
||
|
||
gimple_init_edge_profiler ();
|
||
|
||
n_instrumented = instrument_edges (el);
|
||
|
||
gcc_assert (n_instrumented == num_instrumented);
|
||
|
||
if (flag_profile_values)
|
||
instrument_values (values);
|
||
|
||
/* Commit changes done by instrumentation. */
|
||
gsi_commit_edge_inserts ();
|
||
}
|
||
|
||
free_aux_for_edges ();
|
||
|
||
values.release ();
|
||
free_edge_list (el);
|
||
coverage_end_function (lineno_checksum, cfg_checksum);
|
||
}
|
||
|
||
/* Union find algorithm implementation for the basic blocks using
|
||
aux fields. */
|
||
|
||
static basic_block
|
||
find_group (basic_block bb)
|
||
{
|
||
basic_block group = bb, bb1;
|
||
|
||
while ((basic_block) group->aux != group)
|
||
group = (basic_block) group->aux;
|
||
|
||
/* Compress path. */
|
||
while ((basic_block) bb->aux != group)
|
||
{
|
||
bb1 = (basic_block) bb->aux;
|
||
bb->aux = (void *) group;
|
||
bb = bb1;
|
||
}
|
||
return group;
|
||
}
|
||
|
||
static void
|
||
union_groups (basic_block bb1, basic_block bb2)
|
||
{
|
||
basic_block bb1g = find_group (bb1);
|
||
basic_block bb2g = find_group (bb2);
|
||
|
||
/* ??? I don't have a place for the rank field. OK. Lets go w/o it,
|
||
this code is unlikely going to be performance problem anyway. */
|
||
gcc_assert (bb1g != bb2g);
|
||
|
||
bb1g->aux = bb2g;
|
||
}
|
||
|
||
/* This function searches all of the edges in the program flow graph, and puts
|
||
as many bad edges as possible onto the spanning tree. Bad edges include
|
||
abnormals edges, which can't be instrumented at the moment. Since it is
|
||
possible for fake edges to form a cycle, we will have to develop some
|
||
better way in the future. Also put critical edges to the tree, since they
|
||
are more expensive to instrument. */
|
||
|
||
static void
|
||
find_spanning_tree (struct edge_list *el)
|
||
{
|
||
int i;
|
||
int num_edges = NUM_EDGES (el);
|
||
basic_block bb;
|
||
|
||
/* We use aux field for standard union-find algorithm. */
|
||
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
|
||
bb->aux = bb;
|
||
|
||
/* Add fake edge exit to entry we can't instrument. */
|
||
union_groups (EXIT_BLOCK_PTR, ENTRY_BLOCK_PTR);
|
||
|
||
/* First add all abnormal edges to the tree unless they form a cycle. Also
|
||
add all edges to EXIT_BLOCK_PTR to avoid inserting profiling code behind
|
||
setting return value from function. */
|
||
for (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
if (((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
|
||
|| e->dest == EXIT_BLOCK_PTR)
|
||
&& !EDGE_INFO (e)->ignore
|
||
&& (find_group (e->src) != find_group (e->dest)))
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Abnormal edge %d to %d put to tree\n",
|
||
e->src->index, e->dest->index);
|
||
EDGE_INFO (e)->on_tree = 1;
|
||
union_groups (e->src, e->dest);
|
||
}
|
||
}
|
||
|
||
/* Now insert all critical edges to the tree unless they form a cycle. */
|
||
for (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
if (EDGE_CRITICAL_P (e) && !EDGE_INFO (e)->ignore
|
||
&& find_group (e->src) != find_group (e->dest))
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Critical edge %d to %d put to tree\n",
|
||
e->src->index, e->dest->index);
|
||
EDGE_INFO (e)->on_tree = 1;
|
||
union_groups (e->src, e->dest);
|
||
}
|
||
}
|
||
|
||
/* And now the rest. */
|
||
for (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
if (!EDGE_INFO (e)->ignore
|
||
&& find_group (e->src) != find_group (e->dest))
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "Normal edge %d to %d put to tree\n",
|
||
e->src->index, e->dest->index);
|
||
EDGE_INFO (e)->on_tree = 1;
|
||
union_groups (e->src, e->dest);
|
||
}
|
||
}
|
||
|
||
clear_aux_for_blocks ();
|
||
}
|
||
|
||
/* Perform file-level initialization for branch-prob processing. */
|
||
|
||
void
|
||
init_branch_prob (void)
|
||
{
|
||
int i;
|
||
|
||
total_num_blocks = 0;
|
||
total_num_edges = 0;
|
||
total_num_edges_ignored = 0;
|
||
total_num_edges_instrumented = 0;
|
||
total_num_blocks_created = 0;
|
||
total_num_passes = 0;
|
||
total_num_times_called = 0;
|
||
total_num_branches = 0;
|
||
for (i = 0; i < 20; i++)
|
||
total_hist_br_prob[i] = 0;
|
||
}
|
||
|
||
/* Performs file-level cleanup after branch-prob processing
|
||
is completed. */
|
||
|
||
void
|
||
end_branch_prob (void)
|
||
{
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "\n");
|
||
fprintf (dump_file, "Total number of blocks: %d\n",
|
||
total_num_blocks);
|
||
fprintf (dump_file, "Total number of edges: %d\n", total_num_edges);
|
||
fprintf (dump_file, "Total number of ignored edges: %d\n",
|
||
total_num_edges_ignored);
|
||
fprintf (dump_file, "Total number of instrumented edges: %d\n",
|
||
total_num_edges_instrumented);
|
||
fprintf (dump_file, "Total number of blocks created: %d\n",
|
||
total_num_blocks_created);
|
||
fprintf (dump_file, "Total number of graph solution passes: %d\n",
|
||
total_num_passes);
|
||
if (total_num_times_called != 0)
|
||
fprintf (dump_file, "Average number of graph solution passes: %d\n",
|
||
(total_num_passes + (total_num_times_called >> 1))
|
||
/ total_num_times_called);
|
||
fprintf (dump_file, "Total number of branches: %d\n",
|
||
total_num_branches);
|
||
if (total_num_branches)
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < 10; i++)
|
||
fprintf (dump_file, "%d%% branches in range %d-%d%%\n",
|
||
(total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100
|
||
/ total_num_branches, 5*i, 5*i+5);
|
||
}
|
||
}
|
||
}
|