1204 lines
34 KiB
C
1204 lines
34 KiB
C
/* Calculate branch probabilities, and basic block execution counts.
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Copyright (C) 1990, 1991, 1992, 1993, 1994, 1996, 1997, 1998, 1999,
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2000, 2001 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 2, 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 COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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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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/* ??? The .da files are not safe. Changing the program after creating .da
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files or using different options when compiling with -fbranch-probabilities
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can result the arc data not matching the program. Maybe add instrumented
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arc count to .bbg file? Maybe check whether PFG matches the .bbg file? */
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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 "rtl.h"
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#include "tree.h"
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#include "flags.h"
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#include "insn-config.h"
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#include "output.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 "toplev.h"
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#include "ggc.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "gcov-io.h"
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#include "target.h"
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/* Additional information about the edges we need. */
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struct edge_info
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{
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unsigned int count_valid : 1;
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unsigned int on_tree : 1;
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unsigned int ignore : 1;
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};
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struct bb_info
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{
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unsigned int count_valid : 1;
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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 EDGE_INFO(e) ((struct edge_info *) (e)->aux)
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#define BB_INFO(b) ((struct bb_info *) (b)->aux)
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/* Keep all basic block indexes nonnegative in the gcov output. Index 0
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is used for entry block, last block exit block. */
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#define GCOV_INDEX_TO_BB(i) ((i) == 0 ? ENTRY_BLOCK_PTR \
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: (((i) == n_basic_blocks + 1) \
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? EXIT_BLOCK_PTR : BASIC_BLOCK ((i)-1)))
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#define BB_TO_GCOV_INDEX(bb) ((bb) == ENTRY_BLOCK_PTR ? 0 \
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: ((bb) == EXIT_BLOCK_PTR \
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? n_basic_blocks + 1 : (bb)->index + 1))
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/* Name and file pointer of the output file for the basic block graph. */
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static FILE *bbg_file;
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/* Name and file pointer of the input file for the arc count data. */
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static FILE *da_file;
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/* Pointer of the output file for the basic block/line number map. */
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static FILE *bb_file;
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/* Last source file name written to bb_file. */
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static char *last_bb_file_name;
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/* Used by final, for allocating the proper amount of storage for the
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instrumented arc execution counts. */
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int count_instrumented_edges;
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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_never_executed;
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static int total_num_branches;
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/* Forward declarations. */
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static void find_spanning_tree PARAMS ((struct edge_list *));
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static void init_edge_profiler PARAMS ((void));
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static rtx gen_edge_profiler PARAMS ((int));
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static void instrument_edges PARAMS ((struct edge_list *));
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static void output_gcov_string PARAMS ((const char *, long));
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static void compute_branch_probabilities PARAMS ((void));
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static basic_block find_group PARAMS ((basic_block));
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static void union_groups PARAMS ((basic_block, basic_block));
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/* If non-zero, we need to output a constructor to set up the
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per-object-file data. */
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static int need_func_profiler = 0;
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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 void
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instrument_edges (el)
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struct edge_list *el;
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{
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int i;
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int num_instr_edges = 0;
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int num_edges = NUM_EDGES (el);
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remove_fake_edges ();
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for (i = 0; i < n_basic_blocks + 2; i++)
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{
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basic_block bb = GCOV_INDEX_TO_BB (i);
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edge e = bb->succ;
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while (e)
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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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if (e->flags & EDGE_ABNORMAL)
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abort ();
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if (rtl_dump_file)
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fprintf (rtl_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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need_func_profiler = 1;
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insert_insn_on_edge (
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gen_edge_profiler (total_num_edges_instrumented
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+ num_instr_edges++), e);
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}
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e = e->succ_next;
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}
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}
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total_num_edges_instrumented += num_instr_edges;
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count_instrumented_edges = total_num_edges_instrumented;
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total_num_blocks_created += num_edges;
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if (rtl_dump_file)
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fprintf (rtl_dump_file, "%d edges instrumented\n", num_instr_edges);
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commit_edge_insertions ();
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}
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/* Output STRING to bb_file, surrounded by DELIMITER. */
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static void
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output_gcov_string (string, delimiter)
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const char *string;
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long delimiter;
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{
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long temp;
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/* Write a delimiter to indicate that a file name follows. */
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__write_long (delimiter, bb_file, 4);
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/* Write the string. */
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temp = strlen (string) + 1;
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fwrite (string, temp, 1, bb_file);
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/* Append a few zeros, to align the output to a 4 byte boundary. */
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temp = temp & 0x3;
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if (temp)
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{
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char c[4];
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c[0] = c[1] = c[2] = c[3] = 0;
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fwrite (c, sizeof (char), 4 - temp, bb_file);
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}
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/* Store another delimiter in the .bb file, just to make it easy to find
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the end of the file name. */
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__write_long (delimiter, bb_file, 4);
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}
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/* Compute the branch probabilities for the various branches.
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Annotate them accordingly. */
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static void
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compute_branch_probabilities ()
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{
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int i;
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int num_edges = 0;
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int changes;
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int passes;
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int hist_br_prob[20];
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int num_never_executed;
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int num_branches;
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/* Attach extra info block to each bb. */
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alloc_aux_for_blocks (sizeof (struct bb_info));
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for (i = 0; i < n_basic_blocks + 2; i++)
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{
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basic_block bb = GCOV_INDEX_TO_BB (i);
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edge e;
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for (e = bb->succ; e; e = e->succ_next)
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if (!EDGE_INFO (e)->ignore)
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BB_INFO (bb)->succ_count++;
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for (e = bb->pred; e; e = e->pred_next)
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if (!EDGE_INFO (e)->ignore)
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BB_INFO (bb)->pred_count++;
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}
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/* Avoid predicting entry on exit nodes. */
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BB_INFO (EXIT_BLOCK_PTR)->succ_count = 2;
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BB_INFO (ENTRY_BLOCK_PTR)->pred_count = 2;
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/* For each edge not on the spanning tree, set its execution count from
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the .da file. */
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/* The first count in the .da file is the number of times that the function
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was entered. This is the exec_count for block zero. */
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for (i = 0; i < n_basic_blocks + 2; i++)
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{
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basic_block bb = GCOV_INDEX_TO_BB (i);
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edge e;
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for (e = bb->succ; e; e = e->succ_next)
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if (!EDGE_INFO (e)->ignore && !EDGE_INFO (e)->on_tree)
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{
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num_edges++;
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if (da_file)
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{
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gcov_type value;
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__read_gcov_type (&value, da_file, 8);
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e->count = value;
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}
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else
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e->count = 0;
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EDGE_INFO (e)->count_valid = 1;
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BB_INFO (bb)->succ_count--;
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BB_INFO (e->dest)->pred_count--;
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if (rtl_dump_file)
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{
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fprintf (rtl_dump_file, "\nRead edge from %i to %i, count:",
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bb->index, e->dest->index);
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fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC,
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(HOST_WIDEST_INT) e->count);
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}
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}
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}
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if (rtl_dump_file)
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fprintf (rtl_dump_file, "\n%d edge counts read\n", num_edges);
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/* For every block in the file,
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- if every exit/entrance edge has a known count, then set the block count
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- if the block count is known, and every exit/entrance edge but one has
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a known execution count, then set the count of the remaining edge
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As edge counts are set, decrement the succ/pred count, but don't delete
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the edge, that way we can easily tell when all edges are known, or only
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one edge is unknown. */
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/* The order that the basic blocks are iterated through is important.
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Since the code that finds spanning trees starts with block 0, low numbered
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edges are put on the spanning tree in preference to high numbered edges.
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Hence, most instrumented edges are at the end. Graph solving works much
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faster if we propagate numbers from the end to the start.
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This takes an average of slightly more than 3 passes. */
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changes = 1;
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passes = 0;
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while (changes)
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{
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passes++;
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changes = 0;
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for (i = n_basic_blocks + 1; i >= 0; i--)
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{
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basic_block bb = GCOV_INDEX_TO_BB (i);
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struct bb_info *bi = BB_INFO (bb);
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if (! bi->count_valid)
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{
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if (bi->succ_count == 0)
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{
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edge e;
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gcov_type total = 0;
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for (e = bb->succ; e; e = e->succ_next)
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total += e->count;
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bb->count = total;
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bi->count_valid = 1;
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changes = 1;
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}
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else if (bi->pred_count == 0)
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{
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edge e;
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gcov_type total = 0;
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for (e = bb->pred; e; e = e->pred_next)
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total += e->count;
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bb->count = total;
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bi->count_valid = 1;
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changes = 1;
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}
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}
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if (bi->count_valid)
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{
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if (bi->succ_count == 1)
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{
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edge e;
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gcov_type total = 0;
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/* One of the counts will be invalid, but it is zero,
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so adding it in also doesn't hurt. */
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for (e = bb->succ; e; e = e->succ_next)
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total += e->count;
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/* Seedgeh for the invalid edge, and set its count. */
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for (e = bb->succ; e; e = e->succ_next)
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if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
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break;
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/* Calculate count for remaining edge by conservation. */
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total = bb->count - total;
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if (! e)
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abort ();
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EDGE_INFO (e)->count_valid = 1;
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e->count = total;
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bi->succ_count--;
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BB_INFO (e->dest)->pred_count--;
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changes = 1;
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}
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if (bi->pred_count == 1)
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{
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edge e;
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gcov_type total = 0;
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/* One of the counts will be invalid, but it is zero,
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so adding it in also doesn't hurt. */
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for (e = bb->pred; e; e = e->pred_next)
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total += e->count;
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/* Seedgeh for the invalid edge, and set its count. */
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for (e = bb->pred; e; e = e->pred_next)
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if (! EDGE_INFO (e)->count_valid && ! EDGE_INFO (e)->ignore)
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break;
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/* Calculate count for remaining edge by conservation. */
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total = bb->count - total + e->count;
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if (! e)
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abort ();
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EDGE_INFO (e)->count_valid = 1;
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e->count = total;
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bi->pred_count--;
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BB_INFO (e->src)->succ_count--;
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changes = 1;
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}
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}
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}
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}
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if (rtl_dump_file)
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dump_flow_info (rtl_dump_file);
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total_num_passes += passes;
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if (rtl_dump_file)
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fprintf (rtl_dump_file, "Graph solving took %d passes.\n\n", passes);
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/* If the graph has been correctly solved, every block will have a
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succ and pred count of zero. */
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for (i = 0; i < n_basic_blocks; i++)
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{
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basic_block bb = BASIC_BLOCK (i);
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if (BB_INFO (bb)->succ_count || BB_INFO (bb)->pred_count)
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abort ();
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}
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/* For every edge, calculate its branch probability and add a reg_note
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to the branch insn to indicate this. */
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for (i = 0; i < 20; i++)
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hist_br_prob[i] = 0;
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num_never_executed = 0;
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num_branches = 0;
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||
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for (i = 0; i <= n_basic_blocks + 1; i++)
|
||
{
|
||
basic_block bb = GCOV_INDEX_TO_BB (i);
|
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edge e;
|
||
gcov_type total;
|
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rtx note;
|
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|
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total = bb->count;
|
||
if (total)
|
||
{
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
{
|
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e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total;
|
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if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
|
||
{
|
||
error ("corrupted profile info: prob for %d-%d thought to be %d",
|
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e->src->index, e->dest->index, e->probability);
|
||
e->probability = REG_BR_PROB_BASE / 2;
|
||
}
|
||
}
|
||
if (bb->index >= 0
|
||
&& any_condjump_p (bb->end)
|
||
&& bb->succ->succ_next)
|
||
{
|
||
int prob;
|
||
edge e;
|
||
int index;
|
||
|
||
/* Find the branch edge. It is possible that we do have fake
|
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edges here. */
|
||
for (e = bb->succ; e->flags & (EDGE_FAKE | EDGE_FALLTHRU);
|
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e = e->succ_next)
|
||
continue; /* Loop body has been intentionally left blank. */
|
||
|
||
prob = e->probability;
|
||
index = prob * 20 / REG_BR_PROB_BASE;
|
||
|
||
if (index == 20)
|
||
index = 19;
|
||
hist_br_prob[index]++;
|
||
|
||
note = find_reg_note (bb->end, REG_BR_PROB, 0);
|
||
/* There may be already note put by some other pass, such
|
||
as builtin_expect expander. */
|
||
if (note)
|
||
XEXP (note, 0) = GEN_INT (prob);
|
||
else
|
||
REG_NOTES (bb->end)
|
||
= gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
|
||
REG_NOTES (bb->end));
|
||
num_branches++;
|
||
}
|
||
}
|
||
/* Otherwise distribute the probabilities evenly so we get sane sum.
|
||
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
|
||
{
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
|
||
total ++;
|
||
if (total)
|
||
{
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE)))
|
||
e->probability = REG_BR_PROB_BASE / total;
|
||
else
|
||
e->probability = 0;
|
||
}
|
||
else
|
||
{
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
total ++;
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
e->probability = REG_BR_PROB_BASE / total;
|
||
}
|
||
if (bb->index >= 0
|
||
&& any_condjump_p (bb->end)
|
||
&& bb->succ->succ_next)
|
||
num_branches++, num_never_executed;
|
||
}
|
||
}
|
||
|
||
if (rtl_dump_file)
|
||
{
|
||
fprintf (rtl_dump_file, "%d branches\n", num_branches);
|
||
fprintf (rtl_dump_file, "%d branches never executed\n",
|
||
num_never_executed);
|
||
if (num_branches)
|
||
for (i = 0; i < 10; i++)
|
||
fprintf (rtl_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;
|
||
total_num_never_executed += num_never_executed;
|
||
for (i = 0; i < 20; i++)
|
||
total_hist_br_prob[i] += hist_br_prob[i];
|
||
|
||
fputc ('\n', rtl_dump_file);
|
||
fputc ('\n', rtl_dump_file);
|
||
}
|
||
|
||
free_aux_for_blocks ();
|
||
}
|
||
|
||
/* Instrument and/or analyze program behavior based on program flow graph.
|
||
In either case, this function builds a flow graph for the function being
|
||
compiled. The flow graph is stored in BB_GRAPH.
|
||
|
||
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.
|
||
|
||
When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
|
||
information from a data file containing edge count information from previous
|
||
executions of the function being compiled. In this case, the flow graph is
|
||
annotated with actual execution counts, which are later propagated into the
|
||
rtl for optimization purposes.
|
||
|
||
Main entry point of this file. */
|
||
|
||
void
|
||
branch_prob ()
|
||
{
|
||
int i;
|
||
int num_edges, ignored_edges;
|
||
struct edge_list *el;
|
||
|
||
/* Start of a function. */
|
||
if (flag_test_coverage)
|
||
output_gcov_string (current_function_name, (long) -2);
|
||
|
||
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 (i = 0; i < n_basic_blocks ; i++)
|
||
{
|
||
int need_exit_edge = 0, need_entry_edge = 0;
|
||
int have_exit_edge = 0, have_entry_edge = 0;
|
||
basic_block bb = BASIC_BLOCK (i);
|
||
rtx insn;
|
||
edge e;
|
||
|
||
/* Add fake edges from entry block to the call insns that may return
|
||
twice. The CFG is not quite correct then, as call insn plays more
|
||
role of CODE_LABEL, but for our purposes, everything should be OK,
|
||
as we never insert code to the beggining of basic block. */
|
||
for (insn = bb->head; insn != NEXT_INSN (bb->end);
|
||
insn = NEXT_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == CALL_INSN
|
||
&& find_reg_note (insn, REG_SETJMP, NULL))
|
||
{
|
||
if (GET_CODE (bb->head) == CODE_LABEL
|
||
|| insn != NEXT_INSN (bb->head))
|
||
{
|
||
e = split_block (bb, PREV_INSN (insn));
|
||
make_edge (ENTRY_BLOCK_PTR, e->dest, EDGE_FAKE);
|
||
break;
|
||
}
|
||
else
|
||
{
|
||
/* We should not get abort here, as call to setjmp should not
|
||
be the very first instruction of function. */
|
||
if (!i)
|
||
abort ();
|
||
make_edge (ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
|
||
}
|
||
}
|
||
}
|
||
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
{
|
||
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 (e = bb->pred; e; e = e->pred_next)
|
||
{
|
||
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 (rtl_dump_file)
|
||
fprintf (rtl_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 (rtl_dump_file)
|
||
fprintf (rtl_dump_file, "Adding fake entry edge to bb %i\n",
|
||
bb->index);
|
||
make_edge (ENTRY_BLOCK_PTR, bb, EDGE_FAKE);
|
||
}
|
||
}
|
||
|
||
el = create_edge_list ();
|
||
num_edges = NUM_EDGES (el);
|
||
alloc_aux_for_edges (sizeof (struct edge_info));
|
||
|
||
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++;
|
||
}
|
||
}
|
||
|
||
#ifdef ENABLE_CHECKING
|
||
verify_flow_info ();
|
||
#endif
|
||
|
||
/* Output line number information about each basic block for
|
||
GCOV utility. */
|
||
if (flag_test_coverage)
|
||
{
|
||
int i = 0;
|
||
for (i = 0 ; i < n_basic_blocks; i++)
|
||
{
|
||
basic_block bb = BASIC_BLOCK (i);
|
||
rtx insn = bb->head;
|
||
static int ignore_next_note = 0;
|
||
|
||
/* We are looking for line number notes. Search backward before
|
||
basic block to find correct ones. */
|
||
insn = prev_nonnote_insn (insn);
|
||
if (!insn)
|
||
insn = get_insns ();
|
||
else
|
||
insn = NEXT_INSN (insn);
|
||
|
||
/* Output a zero to the .bb file to indicate that a new
|
||
block list is starting. */
|
||
__write_long (0, bb_file, 4);
|
||
|
||
while (insn != bb->end)
|
||
{
|
||
if (GET_CODE (insn) == NOTE)
|
||
{
|
||
/* Must ignore the line number notes that immediately
|
||
follow the end of an inline function to avoid counting
|
||
it twice. There is a note before the call, and one
|
||
after the call. */
|
||
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_REPEATED_LINE_NUMBER)
|
||
ignore_next_note = 1;
|
||
else if (NOTE_LINE_NUMBER (insn) > 0)
|
||
{
|
||
if (ignore_next_note)
|
||
ignore_next_note = 0;
|
||
else
|
||
{
|
||
/* If this is a new source file, then output the
|
||
file's name to the .bb file. */
|
||
if (! last_bb_file_name
|
||
|| strcmp (NOTE_SOURCE_FILE (insn),
|
||
last_bb_file_name))
|
||
{
|
||
if (last_bb_file_name)
|
||
free (last_bb_file_name);
|
||
last_bb_file_name
|
||
= xstrdup (NOTE_SOURCE_FILE (insn));
|
||
output_gcov_string (NOTE_SOURCE_FILE (insn),
|
||
(long)-1);
|
||
}
|
||
/* Output the line number to the .bb file. Must be
|
||
done after the output_bb_profile_data() call, and
|
||
after the file name is written, to ensure that it
|
||
is correctly handled by gcov. */
|
||
__write_long (NOTE_LINE_NUMBER (insn), bb_file, 4);
|
||
}
|
||
}
|
||
}
|
||
insn = NEXT_INSN (insn);
|
||
}
|
||
}
|
||
__write_long (0, bb_file, 4);
|
||
}
|
||
|
||
/* 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 (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
struct edge_info *inf = EDGE_INFO (e);
|
||
if ((e->flags & EDGE_FAKE) && !inf->ignore && !inf->on_tree)
|
||
{
|
||
inf->ignore = 1;
|
||
ignored_edges++;
|
||
}
|
||
}
|
||
|
||
total_num_blocks += n_basic_blocks + 2;
|
||
if (rtl_dump_file)
|
||
fprintf (rtl_dump_file, "%d basic blocks\n", n_basic_blocks);
|
||
|
||
total_num_edges += num_edges;
|
||
if (rtl_dump_file)
|
||
fprintf (rtl_dump_file, "%d edges\n", num_edges);
|
||
|
||
total_num_edges_ignored += ignored_edges;
|
||
if (rtl_dump_file)
|
||
fprintf (rtl_dump_file, "%d ignored edges\n", ignored_edges);
|
||
|
||
/* Create a .bbg file from which gcov can reconstruct the basic block
|
||
graph. First output the number of basic blocks, and then for every
|
||
edge output the source and target basic block numbers.
|
||
NOTE: The format of this file must be compatible with gcov. */
|
||
|
||
if (flag_test_coverage)
|
||
{
|
||
int flag_bits;
|
||
|
||
/* The plus 2 stands for entry and exit block. */
|
||
__write_long (n_basic_blocks + 2, bbg_file, 4);
|
||
__write_long (num_edges - ignored_edges + 1, bbg_file, 4);
|
||
|
||
for (i = 0; i < n_basic_blocks + 1; i++)
|
||
{
|
||
basic_block bb = GCOV_INDEX_TO_BB (i);
|
||
edge e;
|
||
long count = 0;
|
||
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
if (!EDGE_INFO (e)->ignore)
|
||
count++;
|
||
__write_long (count, bbg_file, 4);
|
||
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
{
|
||
struct edge_info *i = EDGE_INFO (e);
|
||
if (!i->ignore)
|
||
{
|
||
flag_bits = 0;
|
||
if (i->on_tree)
|
||
flag_bits |= 0x1;
|
||
if (e->flags & EDGE_FAKE)
|
||
flag_bits |= 0x2;
|
||
if (e->flags & EDGE_FALLTHRU)
|
||
flag_bits |= 0x4;
|
||
|
||
__write_long (BB_TO_GCOV_INDEX (e->dest), bbg_file, 4);
|
||
__write_long (flag_bits, bbg_file, 4);
|
||
}
|
||
}
|
||
}
|
||
/* Emit fake loopback edge for EXIT block to maintain compatibility with
|
||
old gcov format. */
|
||
__write_long (1, bbg_file, 4);
|
||
__write_long (0, bbg_file, 4);
|
||
__write_long (0x1, bbg_file, 4);
|
||
|
||
/* Emit a -1 to separate the list of all edges from the list of
|
||
loop back edges that follows. */
|
||
__write_long (-1, bbg_file, 4);
|
||
}
|
||
|
||
if (flag_branch_probabilities)
|
||
compute_branch_probabilities ();
|
||
|
||
/* For each edge not on the spanning tree, add counting code as rtl. */
|
||
|
||
if (profile_arc_flag)
|
||
{
|
||
instrument_edges (el);
|
||
allocate_reg_info (max_reg_num (), FALSE, FALSE);
|
||
}
|
||
|
||
remove_fake_edges ();
|
||
/* Re-merge split basic blocks and the mess introduced by
|
||
insert_insn_on_edge. */
|
||
cleanup_cfg (profile_arc_flag ? CLEANUP_EXPENSIVE : 0);
|
||
if (rtl_dump_file)
|
||
dump_flow_info (rtl_dump_file);
|
||
|
||
free_aux_for_edges ();
|
||
free_edge_list (el);
|
||
}
|
||
|
||
/* Union find algorithm implementation for the basic blocks using
|
||
aux fields. */
|
||
|
||
static basic_block
|
||
find_group (bb)
|
||
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 (bb1, bb2)
|
||
basic_block bb1, 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. */
|
||
if (bb1g == bb2g)
|
||
abort ();
|
||
|
||
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 an 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 (el)
|
||
struct edge_list *el;
|
||
{
|
||
int i;
|
||
int num_edges = NUM_EDGES (el);
|
||
|
||
/* We use aux field for standard union-find algorithm. */
|
||
EXIT_BLOCK_PTR->aux = EXIT_BLOCK_PTR;
|
||
ENTRY_BLOCK_PTR->aux = ENTRY_BLOCK_PTR;
|
||
for (i = 0; i < n_basic_blocks; i++)
|
||
BASIC_BLOCK (i)->aux = BASIC_BLOCK (i);
|
||
|
||
/* 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 an cycle. */
|
||
for (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (el, i);
|
||
if ((e->flags & (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_FAKE))
|
||
&& !EDGE_INFO (e)->ignore
|
||
&& (find_group (e->src) != find_group (e->dest)))
|
||
{
|
||
EDGE_INFO (e)->on_tree = 1;
|
||
union_groups (e->src, e->dest);
|
||
}
|
||
}
|
||
|
||
/* Now insert all critical edges to the tree unless they form an 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)))
|
||
{
|
||
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 (find_group (e->src) != find_group (e->dest)
|
||
&& !EDGE_INFO (e)->ignore)
|
||
{
|
||
EDGE_INFO (e)->on_tree = 1;
|
||
union_groups (e->src, e->dest);
|
||
}
|
||
}
|
||
|
||
EXIT_BLOCK_PTR->aux = NULL;
|
||
ENTRY_BLOCK_PTR->aux = NULL;
|
||
for (i = 0; i < n_basic_blocks; i++)
|
||
BASIC_BLOCK (i)->aux = NULL;
|
||
}
|
||
|
||
/* Perform file-level initialization for branch-prob processing. */
|
||
|
||
void
|
||
init_branch_prob (filename)
|
||
const char *filename;
|
||
{
|
||
long len;
|
||
int i;
|
||
|
||
if (flag_test_coverage)
|
||
{
|
||
int len = strlen (filename);
|
||
char *data_file, *bbg_file_name;
|
||
|
||
/* Open an output file for the basic block/line number map. */
|
||
data_file = (char *) alloca (len + 4);
|
||
strcpy (data_file, filename);
|
||
strip_off_ending (data_file, len);
|
||
strcat (data_file, ".bb");
|
||
if ((bb_file = fopen (data_file, "wb")) == 0)
|
||
fatal_io_error ("can't open %s", data_file);
|
||
|
||
/* Open an output file for the program flow graph. */
|
||
bbg_file_name = (char *) alloca (len + 5);
|
||
strcpy (bbg_file_name, filename);
|
||
strip_off_ending (bbg_file_name, len);
|
||
strcat (bbg_file_name, ".bbg");
|
||
if ((bbg_file = fopen (bbg_file_name, "wb")) == 0)
|
||
fatal_io_error ("can't open %s", bbg_file_name);
|
||
|
||
/* Initialize to zero, to ensure that the first file name will be
|
||
written to the .bb file. */
|
||
last_bb_file_name = 0;
|
||
}
|
||
|
||
if (flag_branch_probabilities)
|
||
{
|
||
char *da_file_name;
|
||
|
||
len = strlen (filename);
|
||
da_file_name = (char *) alloca (len + 4);
|
||
strcpy (da_file_name, filename);
|
||
strip_off_ending (da_file_name, len);
|
||
strcat (da_file_name, ".da");
|
||
if ((da_file = fopen (da_file_name, "rb")) == 0)
|
||
warning ("file %s not found, execution counts assumed to be zero",
|
||
da_file_name);
|
||
|
||
/* The first word in the .da file gives the number of instrumented
|
||
edges, which is not needed for our purposes. */
|
||
|
||
if (da_file)
|
||
__read_long (&len, da_file, 8);
|
||
}
|
||
|
||
if (profile_arc_flag)
|
||
init_edge_profiler ();
|
||
|
||
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;
|
||
total_num_never_executed = 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 ()
|
||
{
|
||
if (flag_test_coverage)
|
||
{
|
||
fclose (bb_file);
|
||
fclose (bbg_file);
|
||
}
|
||
|
||
if (flag_branch_probabilities)
|
||
{
|
||
if (da_file)
|
||
{
|
||
long temp;
|
||
/* This seems slightly dangerous, as it presumes the EOF
|
||
flag will not be set until an attempt is made to read
|
||
past the end of the file. */
|
||
if (feof (da_file))
|
||
error (".da file contents exhausted too early");
|
||
/* Should be at end of file now. */
|
||
if (__read_long (&temp, da_file, 8) == 0)
|
||
error (".da file contents not exhausted");
|
||
fclose (da_file);
|
||
}
|
||
}
|
||
|
||
if (rtl_dump_file)
|
||
{
|
||
fprintf (rtl_dump_file, "\n");
|
||
fprintf (rtl_dump_file, "Total number of blocks: %d\n",
|
||
total_num_blocks);
|
||
fprintf (rtl_dump_file, "Total number of edges: %d\n", total_num_edges);
|
||
fprintf (rtl_dump_file, "Total number of ignored edges: %d\n",
|
||
total_num_edges_ignored);
|
||
fprintf (rtl_dump_file, "Total number of instrumented edges: %d\n",
|
||
total_num_edges_instrumented);
|
||
fprintf (rtl_dump_file, "Total number of blocks created: %d\n",
|
||
total_num_blocks_created);
|
||
fprintf (rtl_dump_file, "Total number of graph solution passes: %d\n",
|
||
total_num_passes);
|
||
if (total_num_times_called != 0)
|
||
fprintf (rtl_dump_file, "Average number of graph solution passes: %d\n",
|
||
(total_num_passes + (total_num_times_called >> 1))
|
||
/ total_num_times_called);
|
||
fprintf (rtl_dump_file, "Total number of branches: %d\n",
|
||
total_num_branches);
|
||
fprintf (rtl_dump_file, "Total number of branches never executed: %d\n",
|
||
total_num_never_executed);
|
||
if (total_num_branches)
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < 10; i++)
|
||
fprintf (rtl_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);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* The label used by the edge profiling code. */
|
||
|
||
static rtx profiler_label;
|
||
|
||
/* Initialize the profiler_label. */
|
||
|
||
static void
|
||
init_edge_profiler ()
|
||
{
|
||
/* Generate and save a copy of this so it can be shared. */
|
||
char buf[20];
|
||
ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 2);
|
||
profiler_label = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf));
|
||
ggc_add_rtx_root (&profiler_label, 1);
|
||
}
|
||
|
||
/* Output instructions as RTL to increment the edge execution count. */
|
||
|
||
static rtx
|
||
gen_edge_profiler (edgeno)
|
||
int edgeno;
|
||
{
|
||
enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
|
||
rtx mem_ref, tmp;
|
||
rtx sequence;
|
||
|
||
start_sequence ();
|
||
|
||
tmp = force_reg (Pmode, profiler_label);
|
||
tmp = plus_constant (tmp, GCOV_TYPE_SIZE / BITS_PER_UNIT * edgeno);
|
||
mem_ref = validize_mem (gen_rtx_MEM (mode, tmp));
|
||
|
||
tmp = expand_simple_binop (mode, PLUS, mem_ref, const1_rtx,
|
||
mem_ref, 0, OPTAB_WIDEN);
|
||
|
||
if (tmp != mem_ref)
|
||
emit_move_insn (copy_rtx (mem_ref), tmp);
|
||
|
||
sequence = gen_sequence ();
|
||
end_sequence ();
|
||
return sequence;
|
||
}
|
||
|
||
/* Output code for a constructor that will invoke __bb_init_func, if
|
||
this has not already been done. */
|
||
|
||
void
|
||
output_func_start_profiler ()
|
||
{
|
||
tree fnname, fndecl;
|
||
char *name;
|
||
char buf[20];
|
||
const char *cfnname;
|
||
rtx table_address;
|
||
enum machine_mode mode = mode_for_size (GCOV_TYPE_SIZE, MODE_INT, 0);
|
||
int save_flag_inline_functions = flag_inline_functions;
|
||
int save_flag_test_coverage = flag_test_coverage;
|
||
int save_profile_arc_flag = profile_arc_flag;
|
||
int save_flag_branch_probabilities = flag_branch_probabilities;
|
||
|
||
/* It's either already been output, or we don't need it because we're
|
||
not doing profile-edges. */
|
||
if (! need_func_profiler)
|
||
return;
|
||
|
||
need_func_profiler = 0;
|
||
|
||
/* Synthesize a constructor function to invoke __bb_init_func with a
|
||
pointer to this object file's profile block. */
|
||
|
||
/* Try and make a unique name given the "file function name".
|
||
|
||
And no, I don't like this either. */
|
||
|
||
fnname = get_file_function_name ('I');
|
||
cfnname = IDENTIFIER_POINTER (fnname);
|
||
name = concat (cfnname, "GCOV", NULL);
|
||
fnname = get_identifier (name);
|
||
free (name);
|
||
|
||
fndecl = build_decl (FUNCTION_DECL, fnname,
|
||
build_function_type (void_type_node, NULL_TREE));
|
||
DECL_EXTERNAL (fndecl) = 0;
|
||
|
||
/* It can be a static function as long as collect2 does not have
|
||
to scan the object file to find its ctor/dtor routine. */
|
||
TREE_PUBLIC (fndecl) = ! targetm.have_ctors_dtors;
|
||
|
||
TREE_USED (fndecl) = 1;
|
||
|
||
DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
|
||
|
||
fndecl = pushdecl (fndecl);
|
||
rest_of_decl_compilation (fndecl, 0, 1, 0);
|
||
announce_function (fndecl);
|
||
current_function_decl = fndecl;
|
||
DECL_INITIAL (fndecl) = error_mark_node;
|
||
make_decl_rtl (fndecl, NULL);
|
||
init_function_start (fndecl, input_filename, lineno);
|
||
pushlevel (0);
|
||
expand_function_start (fndecl, 0);
|
||
|
||
/* Actually generate the code to call __bb_init_func. */
|
||
ASM_GENERATE_INTERNAL_LABEL (buf, "LPBX", 0);
|
||
table_address = force_reg (Pmode,
|
||
gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (buf)));
|
||
emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_init_func"), LCT_NORMAL,
|
||
mode, 1, table_address, Pmode);
|
||
|
||
expand_function_end (input_filename, lineno, 0);
|
||
poplevel (1, 0, 1);
|
||
|
||
/* Since fndecl isn't in the list of globals, it would never be emitted
|
||
when it's considered to be 'safe' for inlining, so turn off
|
||
flag_inline_functions. */
|
||
flag_inline_functions = 0;
|
||
|
||
/* Don't instrument the function that turns on instrumentation. Which
|
||
is also handy since we'd get silly warnings about not consuming all
|
||
of our da_file input. */
|
||
flag_test_coverage = 0;
|
||
profile_arc_flag = 0;
|
||
flag_branch_probabilities = 0;
|
||
|
||
rest_of_compilation (fndecl);
|
||
|
||
/* Reset flag_inline_functions to its original value. */
|
||
flag_inline_functions = save_flag_inline_functions;
|
||
flag_test_coverage = save_flag_test_coverage;
|
||
profile_arc_flag = save_profile_arc_flag;
|
||
flag_branch_probabilities = save_flag_branch_probabilities;
|
||
|
||
if (! quiet_flag)
|
||
fflush (asm_out_file);
|
||
current_function_decl = NULL_TREE;
|
||
|
||
if (targetm.have_ctors_dtors)
|
||
(* targetm.asm_out.constructor) (XEXP (DECL_RTL (fndecl), 0),
|
||
DEFAULT_INIT_PRIORITY);
|
||
}
|