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1703 lines
52 KiB
C
1703 lines
52 KiB
C
/* Calculate branch probabilities, and basic block execution counts.
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Copyright (C) 1990, 91-94, 96, 97, 1998 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 GNU CC.
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GNU CC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU CC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License 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 GNU CC; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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/* ??? Really should not put insns inside of LIBCALL sequences, when putting
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insns after a call, should look for the insn setting the retval, and
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insert the insns after that one. */
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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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/* ??? Rearrange code so that the most frequently executed arcs become from
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one block to the next block (i.e. a fall through), move seldom executed
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code outside of loops even at the expense of adding a few branches to
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achieve this, see Dain Sample's UC Berkeley thesis. */
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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 "flags.h"
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#include "insn-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 "tree.h"
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#include "output.h"
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#include "gcov-io.h"
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#include "toplev.h"
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extern char * xmalloc ();
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/* One of these is dynamically created whenever we identify an arc in the
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function. */
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struct adj_list
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{
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int source;
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int target;
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int arc_count;
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unsigned int count_valid : 1;
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unsigned int on_tree : 1;
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unsigned int fake : 1;
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unsigned int fall_through : 1;
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rtx branch_insn;
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struct adj_list *pred_next;
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struct adj_list *succ_next;
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};
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#define ARC_TARGET(ARCPTR) (ARCPTR->target)
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#define ARC_SOURCE(ARCPTR) (ARCPTR->source)
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#define ARC_COUNT(ARCPTR) (ARCPTR->arc_count)
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/* Count the number of basic blocks, and create an array of these structures,
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one for each bb in the function. */
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struct bb_info
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{
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struct adj_list *succ;
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struct adj_list *pred;
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int succ_count;
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int pred_count;
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int exec_count;
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unsigned int count_valid : 1;
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unsigned int on_tree : 1;
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rtx first_insn;
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};
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/* Indexed by label number, gives the basic block number containing that
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label. */
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static int *label_to_bb;
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/* Number of valid entries in the label_to_bb array. */
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static int label_to_bb_size;
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/* Indexed by block index, holds the basic block graph. */
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static struct bb_info *bb_graph;
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/* Name and file pointer of the output file for the basic block graph. */
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static char *bbg_file_name;
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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 char *da_file_name;
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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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/* Indicates whether the next line number note should be output to
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bb_file or not. Used to eliminate a redundant note after an
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expanded inline function call. */
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static int ignore_next_note;
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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_arcs;
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/* Number of executions for the return label. */
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int return_label_execution_count;
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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_arcs;
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static int total_num_arcs_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 init_arc PROTO((struct adj_list *, int, int, rtx));
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static void find_spanning_tree PROTO((int));
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static void expand_spanning_tree PROTO((int));
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static void fill_spanning_tree PROTO((int));
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static void init_arc_profiler PROTO((void));
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static void output_arc_profiler PROTO((int, rtx));
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#ifndef LONG_TYPE_SIZE
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#define LONG_TYPE_SIZE BITS_PER_WORD
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#endif
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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 arc 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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DUMP_FILE, if nonzero, is an rtl dump file we can write to. */
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static void
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instrument_arcs (f, num_blocks, dump_file)
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rtx f;
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int num_blocks;
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FILE *dump_file;
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{
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register int i;
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register struct adj_list *arcptr, *backptr;
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int num_arcs = 0;
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int num_instr_arcs = 0;
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rtx insn;
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/* Instrument the program start. */
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/* Handle block 0 specially, since it will always be instrumented,
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but it doesn't have a valid first_insn or branch_insn. We must
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put the instructions before the NOTE_INSN_FUNCTION_BEG note, so
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that they don't clobber any of the parameters of the current
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function. */
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for (insn = f; insn; insn = NEXT_INSN (insn))
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if (GET_CODE (insn) == NOTE
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&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
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break;
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insn = PREV_INSN (insn);
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need_func_profiler = 1;
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output_arc_profiler (total_num_arcs_instrumented + num_instr_arcs++, insn);
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for (i = 1; i < num_blocks; i++)
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for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next)
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if (! arcptr->on_tree)
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{
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if (dump_file)
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fprintf (dump_file, "Arc %d to %d instrumented\n", i,
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ARC_TARGET (arcptr));
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/* Check to see if this arc is the only exit from its source block,
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or the only entrance to its target block. In either case,
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we don't need to create a new block to instrument the arc. */
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if (bb_graph[i].succ == arcptr && arcptr->succ_next == 0)
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{
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/* Instrument the source block. */
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output_arc_profiler (total_num_arcs_instrumented
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+ num_instr_arcs++,
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PREV_INSN (bb_graph[i].first_insn));
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}
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else if (arcptr == bb_graph[ARC_TARGET (arcptr)].pred
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&& arcptr->pred_next == 0)
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{
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/* Instrument the target block. */
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output_arc_profiler (total_num_arcs_instrumented
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+ num_instr_arcs++,
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PREV_INSN (bb_graph[ARC_TARGET (arcptr)].first_insn));
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}
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else if (arcptr->fall_through)
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{
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/* This is a fall-through; put the instrumentation code after
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the branch that ends this block. */
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for (backptr = bb_graph[i].succ; backptr;
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backptr = backptr->succ_next)
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if (backptr != arcptr)
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break;
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output_arc_profiler (total_num_arcs_instrumented
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+ num_instr_arcs++,
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backptr->branch_insn);
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}
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else
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{
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/* Must emit a new basic block to hold the arc counting code. */
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enum rtx_code code = GET_CODE (PATTERN (arcptr->branch_insn));
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if (code == SET)
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{
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/* Create the new basic block right after the branch.
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Invert the branch so that it jumps past the end of the new
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block. The new block will consist of the instrumentation
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code, and a jump to the target of this arc. */
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int this_is_simplejump = simplejump_p (arcptr->branch_insn);
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rtx new_label = gen_label_rtx ();
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rtx old_label, set_src;
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rtx after = arcptr->branch_insn;
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/* Simplejumps can't reach here. */
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if (this_is_simplejump)
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abort ();
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/* We can't use JUMP_LABEL, because it won't be set if we
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are compiling without optimization. */
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set_src = SET_SRC (single_set (arcptr->branch_insn));
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if (GET_CODE (set_src) == LABEL_REF)
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old_label = set_src;
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else if (GET_CODE (set_src) != IF_THEN_ELSE)
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abort ();
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else if (XEXP (set_src, 1) == pc_rtx)
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old_label = XEXP (XEXP (set_src, 2), 0);
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else
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old_label = XEXP (XEXP (set_src, 1), 0);
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/* Set the JUMP_LABEL so that redirect_jump will work. */
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JUMP_LABEL (arcptr->branch_insn) = old_label;
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/* Add a use for OLD_LABEL that will be needed when we emit
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the JUMP_INSN below. If we don't do this here,
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`invert_jump' might delete it for us. We must add two
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when not optimizing, because the NUSES is zero now,
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but must be at least two to prevent the label from being
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deleted. */
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LABEL_NUSES (old_label) += 2;
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/* Emit the insns for the new block in reverse order,
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since that is most convenient. */
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if (this_is_simplejump)
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{
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after = NEXT_INSN (arcptr->branch_insn);
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if (! redirect_jump (arcptr->branch_insn, new_label))
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/* Don't know what to do if this branch won't
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redirect. */
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abort ();
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}
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else
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{
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if (! invert_jump (arcptr->branch_insn, new_label))
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/* Don't know what to do if this branch won't invert. */
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abort ();
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emit_label_after (new_label, after);
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LABEL_NUSES (new_label)++;
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}
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emit_barrier_after (after);
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emit_jump_insn_after (gen_jump (old_label), after);
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JUMP_LABEL (NEXT_INSN (after)) = old_label;
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/* Instrument the source arc. */
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output_arc_profiler (total_num_arcs_instrumented
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+ num_instr_arcs++,
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after);
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if (this_is_simplejump)
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{
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emit_label_after (new_label, after);
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LABEL_NUSES (new_label)++;
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}
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}
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else if (code == ADDR_VEC || code == ADDR_DIFF_VEC)
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{
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/* A table jump. Create a new basic block immediately
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after the table, by emitting a barrier, a label, a
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counting note, and a jump to the old label. Put the
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new label in the table. */
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rtx new_label = gen_label_rtx ();
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rtx old_lref, new_lref;
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int index;
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/* Must determine the old_label reference, do this
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by counting the arcs after this one, which will
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give the index of our label in the table. */
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index = 0;
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for (backptr = arcptr->succ_next; backptr;
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backptr = backptr->succ_next)
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index++;
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old_lref = XVECEXP (PATTERN (arcptr->branch_insn),
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(code == ADDR_DIFF_VEC), index);
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/* Emit the insns for the new block in reverse order,
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since that is most convenient. */
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emit_jump_insn_after (gen_jump (XEXP (old_lref, 0)),
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arcptr->branch_insn);
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JUMP_LABEL (NEXT_INSN (arcptr->branch_insn))
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= XEXP (old_lref, 0);
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/* Instrument the source arc. */
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output_arc_profiler (total_num_arcs_instrumented
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+ num_instr_arcs++,
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arcptr->branch_insn);
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emit_label_after (new_label, arcptr->branch_insn);
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LABEL_NUSES (NEXT_INSN (arcptr->branch_insn))++;
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emit_barrier_after (arcptr->branch_insn);
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/* Fix up the table jump. */
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new_lref = gen_rtx_LABEL_REF (Pmode, new_label);
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XVECEXP (PATTERN (arcptr->branch_insn),
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(code == ADDR_DIFF_VEC), index) = new_lref;
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}
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else
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abort ();
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num_arcs += 1;
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if (dump_file)
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fprintf (dump_file,
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"Arc %d to %d needed new basic block\n", i,
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ARC_TARGET (arcptr));
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}
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}
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total_num_arcs_instrumented += num_instr_arcs;
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count_instrumented_arcs = total_num_arcs_instrumented;
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total_num_blocks_created += num_arcs;
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if (dump_file)
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{
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fprintf (dump_file, "%d arcs instrumented\n", num_instr_arcs);
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fprintf (dump_file, "%d extra basic blocks created\n", num_arcs);
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}
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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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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 the
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end of the file name. */
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__write_long (delimiter, bb_file, 4);
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}
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/* Return TRUE if this insn must be a tablejump entry insn. This works for
|
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the MIPS port, but may give false negatives for some targets. */
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int
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tablejump_entry_p (insn, label)
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rtx insn, label;
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{
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rtx next = next_active_insn (insn);
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enum rtx_code code = GET_CODE (PATTERN (next));
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if (code != ADDR_DIFF_VEC && code != ADDR_VEC)
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return 0;
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if (PREV_INSN (next) == XEXP (label, 0))
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return 1;
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return 0;
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||
}
|
||
|
||
/* Instrument and/or analyze program behavior based on program flow graph.
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In either case, this function builds a flow graph for the function being
|
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compiled. The flow graph is stored in BB_GRAPH.
|
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|
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When FLAG_PROFILE_ARCS is nonzero, this function instruments the arcs in
|
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the flow graph that are needed to reconstruct the dynamic behavior of the
|
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flow graph.
|
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When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary
|
||
information from a data file containing arc 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.
|
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|
||
Main entry point of this file. */
|
||
|
||
void
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||
branch_prob (f, dump_file)
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||
rtx f;
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||
FILE *dump_file;
|
||
{
|
||
int i, num_blocks;
|
||
struct adj_list *arcptr;
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||
int num_arcs, changes, passes;
|
||
int total, prob;
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||
int hist_br_prob[20], num_never_executed, num_branches;
|
||
/* Set to non-zero if we got bad count information. */
|
||
int bad_counts = 0;
|
||
|
||
/* start of a function. */
|
||
if (flag_test_coverage)
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||
output_gcov_string (current_function_name, (long) -2);
|
||
|
||
/* Execute this only if doing arc profiling or branch probabilities. */
|
||
if (! profile_arc_flag && ! flag_branch_probabilities
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||
&& ! flag_test_coverage)
|
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abort ();
|
||
|
||
total_num_times_called++;
|
||
|
||
/* Create an array label_to_bb of ints of size max_label_num. */
|
||
label_to_bb_size = max_label_num ();
|
||
label_to_bb = (int *) oballoc (label_to_bb_size * sizeof (int));
|
||
bzero ((char *) label_to_bb, label_to_bb_size * sizeof (int));
|
||
|
||
/* Scan the insns in the function, count the number of basic blocks
|
||
present. When a code label is passed, set label_to_bb[label] = bb
|
||
number. */
|
||
|
||
/* The first block found will be block 1, so that function entry can be
|
||
block 0. */
|
||
|
||
{
|
||
register RTX_CODE prev_code = JUMP_INSN;
|
||
register RTX_CODE code;
|
||
register rtx insn;
|
||
register int i;
|
||
int block_separator_emitted = 0;
|
||
|
||
ignore_next_note = 0;
|
||
|
||
for (insn = NEXT_INSN (f), i = 0; insn; insn = NEXT_INSN (insn))
|
||
{
|
||
code = GET_CODE (insn);
|
||
|
||
if (code == BARRIER)
|
||
;
|
||
else if (code == CODE_LABEL)
|
||
/* This label is part of the next block, but we can't increment
|
||
block number yet since there might be multiple labels. */
|
||
label_to_bb[CODE_LABEL_NUMBER (insn)] = i + 1;
|
||
/* We make NOTE_INSN_SETJMP notes into a block of their own, so that
|
||
they can be the target of the fake arc for the setjmp call.
|
||
This avoids creating cycles of fake arcs, which would happen if
|
||
the block after the setjmp call contained a call insn. */
|
||
else if ((prev_code == JUMP_INSN || prev_code == CALL_INSN
|
||
|| prev_code == CODE_LABEL || prev_code == BARRIER)
|
||
&& (GET_RTX_CLASS (code) == 'i'
|
||
|| (code == NOTE
|
||
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP)))
|
||
{
|
||
i += 1;
|
||
|
||
/* Emit the block separator if it hasn't already been emitted. */
|
||
if (flag_test_coverage && ! block_separator_emitted)
|
||
{
|
||
/* Output a zero to the .bb file to indicate that a new
|
||
block list is starting. */
|
||
__write_long (0, bb_file, 4);
|
||
}
|
||
block_separator_emitted = 0;
|
||
}
|
||
/* If flag_test_coverage is true, then we must add an entry to the
|
||
.bb file for every note. */
|
||
else if (code == NOTE && flag_test_coverage)
|
||
{
|
||
/* 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_REPEATED_LINE_NUMBER)
|
||
ignore_next_note = 1;
|
||
else if (NOTE_LINE_NUMBER (insn) > 0)
|
||
{
|
||
if (ignore_next_note)
|
||
ignore_next_note = 0;
|
||
else
|
||
{
|
||
/* Emit a block separator here to ensure that a NOTE
|
||
immediately following a JUMP_INSN or CALL_INSN will end
|
||
up in the right basic block list. */
|
||
if ((prev_code == JUMP_INSN || prev_code == CALL_INSN
|
||
|| prev_code == CODE_LABEL || prev_code == BARRIER)
|
||
&& ! block_separator_emitted)
|
||
{
|
||
/* Output a zero to the .bb file to indicate that
|
||
a new block list is starting. */
|
||
__write_long (0, bb_file, 4);
|
||
|
||
block_separator_emitted = 1;
|
||
}
|
||
|
||
/* 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
|
||
= xmalloc (strlen (NOTE_SOURCE_FILE (insn)) + 1);
|
||
strcpy (last_bb_file_name, 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);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (code != NOTE)
|
||
prev_code = code;
|
||
else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP)
|
||
prev_code = CALL_INSN;
|
||
}
|
||
|
||
/* Allocate last `normal' entry for bb_graph. */
|
||
|
||
/* The last insn was a jump, call, or label. In that case we have
|
||
a block at the end of the function with no insns. */
|
||
if (prev_code == JUMP_INSN || prev_code == CALL_INSN
|
||
|| prev_code == CODE_LABEL || prev_code == BARRIER)
|
||
{
|
||
i++;
|
||
|
||
/* Emit the block separator if it hasn't already been emitted. */
|
||
if (flag_test_coverage && ! block_separator_emitted)
|
||
{
|
||
/* Output a zero to the .bb file to indicate that a new
|
||
block list is starting. */
|
||
__write_long (0, bb_file, 4);
|
||
}
|
||
}
|
||
|
||
/* Create another block to stand for EXIT, and make all return insns, and
|
||
the last basic block point here. Add one more to account for block
|
||
zero. */
|
||
num_blocks = i + 2;
|
||
}
|
||
|
||
total_num_blocks += num_blocks;
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d basic blocks\n", num_blocks);
|
||
|
||
/* If we are only doing test coverage here, then return now. */
|
||
if (! profile_arc_flag && ! flag_branch_probabilities)
|
||
return;
|
||
|
||
/* Create and initialize the arrays that will hold bb_graph
|
||
and execution count info. */
|
||
|
||
bb_graph = (struct bb_info *) alloca (num_blocks * sizeof (struct bb_info));
|
||
bzero ((char *) bb_graph, (sizeof (struct bb_info) * num_blocks));
|
||
|
||
{
|
||
/* Scan the insns again:
|
||
- at the entry to each basic block, increment the predecessor count
|
||
(and successor of previous block) if it is a fall through entry,
|
||
create adj_list entries for this and the previous block
|
||
- at each jump insn, increment predecessor/successor counts for
|
||
target/source basic blocks, add this insn to pred/succ lists.
|
||
|
||
This also cannot be broken out as a separate subroutine
|
||
because it uses `alloca'. */
|
||
|
||
register RTX_CODE prev_code = JUMP_INSN;
|
||
register RTX_CODE code;
|
||
register rtx insn;
|
||
register int i;
|
||
int fall_through = 0;
|
||
struct adj_list *arcptr;
|
||
int dest = 0;
|
||
|
||
/* Block 0 always falls through to block 1. */
|
||
num_arcs = 0;
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
init_arc (arcptr, 0, 1, 0);
|
||
arcptr->fall_through = 1;
|
||
num_arcs++;
|
||
|
||
/* Add a fake fall through arc from the last block to block 0, to make the
|
||
graph complete. */
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
init_arc (arcptr, num_blocks - 1, 0, 0);
|
||
arcptr->fake = 1;
|
||
num_arcs++;
|
||
|
||
/* Exit must be one node of the graph, and all exits from the function
|
||
must point there. When see a return branch, must point the arc to the
|
||
exit node. */
|
||
|
||
/* Must start scan with second insn in function as above. */
|
||
for (insn = NEXT_INSN (f), i = 0; insn; insn = NEXT_INSN (insn))
|
||
{
|
||
code = GET_CODE (insn);
|
||
|
||
if (code == BARRIER)
|
||
fall_through = 0;
|
||
else if (code == CODE_LABEL)
|
||
;
|
||
/* We make NOTE_INSN_SETJMP notes into a block of their own, so that
|
||
they can be the target of the fake arc for the setjmp call.
|
||
This avoids creating cycles of fake arcs, which would happen if
|
||
the block after the setjmp call ended with a call. */
|
||
else if ((prev_code == JUMP_INSN || prev_code == CALL_INSN
|
||
|| prev_code == CODE_LABEL || prev_code == BARRIER)
|
||
&& (GET_RTX_CLASS (code) == 'i'
|
||
|| (code == NOTE
|
||
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP)))
|
||
{
|
||
/* This is the first insn of the block. */
|
||
i += 1;
|
||
if (fall_through)
|
||
{
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
init_arc (arcptr, i - 1, i, 0);
|
||
arcptr->fall_through = 1;
|
||
|
||
num_arcs++;
|
||
}
|
||
fall_through = 1;
|
||
bb_graph[i].first_insn = insn;
|
||
}
|
||
else if (code == NOTE)
|
||
{;}
|
||
|
||
if (code == CALL_INSN)
|
||
{
|
||
/* In the normal case, the call returns, and this is just like
|
||
a branch fall through. */
|
||
fall_through = 1;
|
||
|
||
/* Setjmp may return more times than called, so to make the graph
|
||
solvable, add a fake arc from the function entrance to the
|
||
next block.
|
||
|
||
All other functions may return fewer times than called (if
|
||
a descendent call longjmp or exit), so to make the graph
|
||
solvable, add a fake arc to the function exit from the
|
||
current block.
|
||
|
||
Distinguish the cases by checking for a SETJUMP note.
|
||
A call_insn can be the last ins of a function, so must check
|
||
to see if next insn actually exists. */
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
if (NEXT_INSN (insn)
|
||
&& GET_CODE (NEXT_INSN (insn)) == NOTE
|
||
&& NOTE_LINE_NUMBER (NEXT_INSN (insn)) == NOTE_INSN_SETJMP)
|
||
init_arc (arcptr, 0, i+1, insn);
|
||
else
|
||
init_arc (arcptr, i, num_blocks-1, insn);
|
||
arcptr->fake = 1;
|
||
num_arcs++;
|
||
}
|
||
else if (code == JUMP_INSN)
|
||
{
|
||
rtx tem, pattern = PATTERN (insn);
|
||
rtx tablejump = 0;
|
||
|
||
/* If running without optimization, then jump label won't be valid,
|
||
so we must search for the destination label in that case.
|
||
We have to handle tablejumps and returns specially anyways, so
|
||
we don't check the JUMP_LABEL at all here. */
|
||
|
||
/* ??? This code should be rewritten. We need a more elegant way
|
||
to find the LABEL_REF. We need a more elegant way to
|
||
differentiate tablejump entries from computed gotos.
|
||
We should perhaps reuse code from flow to compute the CFG
|
||
instead of trying to compute it here.
|
||
|
||
We can't use current_function_has_computed_jump, because that
|
||
is calculated later by flow. We can't use computed_jump_p,
|
||
because that returns true for tablejump entry insns for some
|
||
targets, e.g. HPPA and MIPS. */
|
||
|
||
if (GET_CODE (pattern) == PARALLEL)
|
||
{
|
||
/* This assumes that PARALLEL jumps with a USE are
|
||
tablejump entry jumps. The same assumption can be found
|
||
in computed_jump_p. */
|
||
/* Make an arc from this jump to the label of the
|
||
jump table. This will instrument the number of
|
||
times the switch statement is executed. */
|
||
if (GET_CODE (XVECEXP (pattern, 0, 1)) == USE)
|
||
{
|
||
tem = XEXP (XVECEXP (pattern, 0, 1), 0);
|
||
if (GET_CODE (tem) != LABEL_REF)
|
||
abort ();
|
||
dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (tem, 0))];
|
||
}
|
||
else if (GET_CODE (XVECEXP (pattern, 0, 0)) == SET
|
||
&& SET_DEST (XVECEXP (pattern, 0, 0)) == pc_rtx)
|
||
{
|
||
tem = SET_SRC (XVECEXP (pattern, 0, 0));
|
||
if (GET_CODE (tem) == PLUS
|
||
&& GET_CODE (XEXP (tem, 1)) == LABEL_REF)
|
||
{
|
||
tem = XEXP (tem, 1);
|
||
dest = label_to_bb [CODE_LABEL_NUMBER (XEXP (tem, 0))];
|
||
}
|
||
}
|
||
else
|
||
abort ();
|
||
}
|
||
else if (GET_CODE (pattern) == ADDR_VEC
|
||
|| GET_CODE (pattern) == ADDR_DIFF_VEC)
|
||
tablejump = pattern;
|
||
else if (GET_CODE (pattern) == RETURN)
|
||
dest = num_blocks - 1;
|
||
else if (GET_CODE (pattern) != SET)
|
||
abort ();
|
||
else if ((tem = SET_SRC (pattern))
|
||
&& GET_CODE (tem) == LABEL_REF)
|
||
dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (tem, 0))];
|
||
/* Recognize HPPA table jump entry. This code is similar to
|
||
the code above in the PARALLEL case. */
|
||
else if (GET_CODE (tem) == PLUS
|
||
&& GET_CODE (XEXP (tem, 0)) == MEM
|
||
&& GET_CODE (XEXP (XEXP (tem, 0), 0)) == PLUS
|
||
&& GET_CODE (XEXP (XEXP (XEXP (tem, 0), 0), 0)) == PC
|
||
&& GET_CODE (XEXP (tem, 1)) == LABEL_REF
|
||
&& tablejump_entry_p (insn, XEXP (tem, 1)))
|
||
dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (XEXP (tem, 1), 0))];
|
||
/* Recognize the MIPS table jump entry. */
|
||
else if (GET_CODE (tem) == PLUS
|
||
&& GET_CODE (XEXP (tem, 0)) == REG
|
||
&& GET_CODE (XEXP (tem, 1)) == LABEL_REF
|
||
&& tablejump_entry_p (insn, XEXP (tem, 1)))
|
||
dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (XEXP (tem, 1), 0))];
|
||
else
|
||
{
|
||
rtx label_ref;
|
||
|
||
/* Must be an IF_THEN_ELSE branch. If it isn't, assume it
|
||
is a computed goto, which aren't supported yet. */
|
||
if (GET_CODE (tem) != IF_THEN_ELSE)
|
||
fatal ("-fprofile-arcs does not support computed gotos");
|
||
if (XEXP (tem, 1) != pc_rtx)
|
||
label_ref = XEXP (tem, 1);
|
||
else
|
||
label_ref = XEXP (tem, 2);
|
||
dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (label_ref, 0))];
|
||
}
|
||
|
||
if (tablejump)
|
||
{
|
||
int diff_vec_p = GET_CODE (tablejump) == ADDR_DIFF_VEC;
|
||
int len = XVECLEN (tablejump, diff_vec_p);
|
||
int k;
|
||
|
||
for (k = 0; k < len; k++)
|
||
{
|
||
rtx tem = XEXP (XVECEXP (tablejump, diff_vec_p, k), 0);
|
||
dest = label_to_bb[CODE_LABEL_NUMBER (tem)];
|
||
|
||
arcptr = (struct adj_list *) alloca (sizeof(struct adj_list));
|
||
init_arc (arcptr, i, dest, insn);
|
||
|
||
num_arcs++;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
init_arc (arcptr, i, dest, insn);
|
||
|
||
num_arcs++;
|
||
}
|
||
|
||
/* Determine whether or not this jump will fall through.
|
||
Unconditional jumps and returns are not always followed by
|
||
barriers. */
|
||
pattern = PATTERN (insn);
|
||
if (GET_CODE (pattern) == PARALLEL
|
||
|| GET_CODE (pattern) == RETURN)
|
||
fall_through = 0;
|
||
else if (GET_CODE (pattern) == ADDR_VEC
|
||
|| GET_CODE (pattern) == ADDR_DIFF_VEC)
|
||
/* These aren't actually jump insns, but they never fall
|
||
through, so... */
|
||
fall_through = 0;
|
||
else
|
||
{
|
||
if (GET_CODE (pattern) != SET || SET_DEST (pattern) != pc_rtx)
|
||
abort ();
|
||
if (GET_CODE (SET_SRC (pattern)) != IF_THEN_ELSE)
|
||
fall_through = 0;
|
||
}
|
||
}
|
||
|
||
if (code != NOTE)
|
||
prev_code = code;
|
||
else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP)
|
||
{
|
||
/* Make a fake insn to tag our notes on. */
|
||
bb_graph[i].first_insn = insn
|
||
= emit_insn_after (gen_rtx_USE (VOIDmode, stack_pointer_rtx),
|
||
insn);
|
||
prev_code = CALL_INSN;
|
||
}
|
||
}
|
||
|
||
/* If the code at the end of the function would give a new block, then
|
||
do the following. */
|
||
|
||
if (prev_code == JUMP_INSN || prev_code == CALL_INSN
|
||
|| prev_code == CODE_LABEL || prev_code == BARRIER)
|
||
{
|
||
if (fall_through)
|
||
{
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
init_arc (arcptr, i, i + 1, 0);
|
||
arcptr->fall_through = 1;
|
||
|
||
num_arcs++;
|
||
}
|
||
|
||
/* This may not be a real insn, but that should not cause a problem. */
|
||
bb_graph[i+1].first_insn = get_last_insn ();
|
||
}
|
||
|
||
/* There is always a fake arc from the last block of the function
|
||
to the function exit block. */
|
||
arcptr = (struct adj_list *) alloca (sizeof (struct adj_list));
|
||
init_arc (arcptr, num_blocks-2, num_blocks-1, 0);
|
||
arcptr->fake = 1;
|
||
num_arcs++;
|
||
}
|
||
|
||
total_num_arcs += num_arcs;
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d arcs\n", num_arcs);
|
||
|
||
/* Create spanning tree from basic block graph, mark each arc that is
|
||
on the spanning tree. */
|
||
|
||
/* To reduce the instrumentation cost, make two passes over the tree.
|
||
First, put as many must-split (crowded and fake) arcs on the tree as
|
||
possible, then on the second pass fill in the rest of the tree.
|
||
Note that the spanning tree is considered undirected, so that as many
|
||
must-split arcs as possible can be put on it.
|
||
|
||
Fallthrough arcs which are crowded should not be chosen on the first
|
||
pass, since they do not require creating a new basic block. These
|
||
arcs will have fall_through set. */
|
||
|
||
find_spanning_tree (num_blocks);
|
||
|
||
/* Create a .bbg file from which gcov can reconstruct the basic block
|
||
graph. First output the number of basic blocks, and then for every
|
||
arc 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;
|
||
|
||
__write_long (num_blocks, bbg_file, 4);
|
||
__write_long (num_arcs, bbg_file, 4);
|
||
|
||
for (i = 0; i < num_blocks; i++)
|
||
{
|
||
long count = 0;
|
||
for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next)
|
||
count++;
|
||
__write_long (count, bbg_file, 4);
|
||
|
||
for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next)
|
||
{
|
||
flag_bits = 0;
|
||
if (arcptr->on_tree)
|
||
flag_bits |= 0x1;
|
||
if (arcptr->fake)
|
||
flag_bits |= 0x2;
|
||
if (arcptr->fall_through)
|
||
flag_bits |= 0x4;
|
||
|
||
__write_long (ARC_TARGET (arcptr), bbg_file, 4);
|
||
__write_long (flag_bits, bbg_file, 4);
|
||
}
|
||
}
|
||
|
||
/* Emit a -1 to separate the list of all arcs from the list of
|
||
loop back edges that follows. */
|
||
__write_long (-1, bbg_file, 4);
|
||
}
|
||
|
||
/* For each arc not on the spanning tree, add counting code as rtl. */
|
||
|
||
if (profile_arc_flag)
|
||
{
|
||
instrument_arcs (f, num_blocks, dump_file);
|
||
allocate_reg_info (max_reg_num (), FALSE, FALSE);
|
||
}
|
||
|
||
/* Execute the rest only if doing branch probabilities. */
|
||
if (! flag_branch_probabilities)
|
||
return;
|
||
|
||
/* For each arc 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. */
|
||
|
||
num_arcs = 0;
|
||
for (i = 0; i < num_blocks; i++)
|
||
for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next)
|
||
if (! arcptr->on_tree)
|
||
{
|
||
num_arcs++;
|
||
if (da_file)
|
||
{
|
||
long value;
|
||
__read_long (&value, da_file, 8);
|
||
ARC_COUNT (arcptr) = value;
|
||
}
|
||
else
|
||
ARC_COUNT (arcptr) = 0;
|
||
arcptr->count_valid = 1;
|
||
bb_graph[i].succ_count--;
|
||
bb_graph[ARC_TARGET (arcptr)].pred_count--;
|
||
}
|
||
|
||
if (dump_file)
|
||
fprintf (dump_file, "%d arc counts read\n", num_arcs);
|
||
|
||
/* For every block in the file,
|
||
- if every exit/entrance arc has a known count, then set the block count
|
||
- if the block count is known, and every exit/entrance arc but one has
|
||
a known execution count, then set the count of the remaining arc
|
||
|
||
As arc counts are set, decrement the succ/pred count, but don't delete
|
||
the arc, that way we can easily tell when all arcs are known, or only
|
||
one arc 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
|
||
arcs are put on the spanning tree in preference to high numbered arcs.
|
||
Hence, most instrumented arcs 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 (i = num_blocks - 1; i >= 0; i--)
|
||
{
|
||
struct bb_info *binfo = &bb_graph[i];
|
||
if (! binfo->count_valid)
|
||
{
|
||
if (binfo->succ_count == 0)
|
||
{
|
||
total = 0;
|
||
for (arcptr = binfo->succ; arcptr;
|
||
arcptr = arcptr->succ_next)
|
||
total += ARC_COUNT (arcptr);
|
||
binfo->exec_count = total;
|
||
binfo->count_valid = 1;
|
||
changes = 1;
|
||
}
|
||
else if (binfo->pred_count == 0)
|
||
{
|
||
total = 0;
|
||
for (arcptr = binfo->pred; arcptr;
|
||
arcptr = arcptr->pred_next)
|
||
total += ARC_COUNT (arcptr);
|
||
binfo->exec_count = total;
|
||
binfo->count_valid = 1;
|
||
changes = 1;
|
||
}
|
||
}
|
||
if (binfo->count_valid)
|
||
{
|
||
if (binfo->succ_count == 1)
|
||
{
|
||
total = 0;
|
||
/* One of the counts will be invalid, but it is zero,
|
||
so adding it in also doesn't hurt. */
|
||
for (arcptr = binfo->succ; arcptr;
|
||
arcptr = arcptr->succ_next)
|
||
total += ARC_COUNT (arcptr);
|
||
/* Calculate count for remaining arc by conservation. */
|
||
total = binfo->exec_count - total;
|
||
/* Search for the invalid arc, and set its count. */
|
||
for (arcptr = binfo->succ; arcptr;
|
||
arcptr = arcptr->succ_next)
|
||
if (! arcptr->count_valid)
|
||
break;
|
||
if (! arcptr)
|
||
abort ();
|
||
arcptr->count_valid = 1;
|
||
ARC_COUNT (arcptr) = total;
|
||
binfo->succ_count--;
|
||
|
||
bb_graph[ARC_TARGET (arcptr)].pred_count--;
|
||
changes = 1;
|
||
}
|
||
if (binfo->pred_count == 1)
|
||
{
|
||
total = 0;
|
||
/* One of the counts will be invalid, but it is zero,
|
||
so adding it in also doesn't hurt. */
|
||
for (arcptr = binfo->pred; arcptr;
|
||
arcptr = arcptr->pred_next)
|
||
total += ARC_COUNT (arcptr);
|
||
/* Calculate count for remaining arc by conservation. */
|
||
total = binfo->exec_count - total;
|
||
/* Search for the invalid arc, and set its count. */
|
||
for (arcptr = binfo->pred; arcptr;
|
||
arcptr = arcptr->pred_next)
|
||
if (! arcptr->count_valid)
|
||
break;
|
||
if (! arcptr)
|
||
abort ();
|
||
arcptr->count_valid = 1;
|
||
ARC_COUNT (arcptr) = total;
|
||
binfo->pred_count--;
|
||
|
||
bb_graph[ARC_SOURCE (arcptr)].succ_count--;
|
||
changes = 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
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 (i = 0; i < num_blocks; i++)
|
||
{
|
||
struct bb_info *binfo = &bb_graph[i];
|
||
if (binfo->succ_count || binfo->pred_count)
|
||
abort ();
|
||
}
|
||
|
||
/* For every arc, 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_never_executed = 0;
|
||
num_branches = 0;
|
||
|
||
for (i = 0; i < num_blocks; i++)
|
||
{
|
||
struct bb_info *binfo = &bb_graph[i];
|
||
|
||
total = binfo->exec_count;
|
||
for (arcptr = binfo->succ; arcptr; arcptr = arcptr->succ_next)
|
||
{
|
||
if (arcptr->branch_insn)
|
||
{
|
||
/* This calculates the branch probability as an integer between
|
||
0 and REG_BR_PROB_BASE, properly rounded to the nearest
|
||
integer. Perform the arithmetic in double to avoid
|
||
overflowing the range of ints. */
|
||
|
||
if (total == 0)
|
||
prob = -1;
|
||
else
|
||
{
|
||
rtx pat = PATTERN (arcptr->branch_insn);
|
||
|
||
prob = (((double)ARC_COUNT (arcptr) * REG_BR_PROB_BASE)
|
||
+ (total >> 1)) / total;
|
||
if (prob < 0 || prob > REG_BR_PROB_BASE)
|
||
{
|
||
if (dump_file)
|
||
fprintf (dump_file, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n",
|
||
ARC_SOURCE (arcptr), ARC_TARGET (arcptr),
|
||
prob);
|
||
|
||
bad_counts = 1;
|
||
prob = REG_BR_PROB_BASE / 2;
|
||
}
|
||
|
||
/* Match up probability with JUMP pattern. */
|
||
|
||
if (GET_CODE (pat) == SET
|
||
&& GET_CODE (SET_SRC (pat)) == IF_THEN_ELSE)
|
||
{
|
||
if (ARC_TARGET (arcptr) == ARC_SOURCE (arcptr) + 1)
|
||
{
|
||
/* A fall through arc should never have a
|
||
branch insn. */
|
||
abort ();
|
||
}
|
||
else
|
||
{
|
||
/* This is the arc for the taken branch. */
|
||
if (GET_CODE (XEXP (SET_SRC (pat), 2)) != PC)
|
||
prob = REG_BR_PROB_BASE - prob;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (prob == -1)
|
||
num_never_executed++;
|
||
else
|
||
{
|
||
int index = prob * 20 / REG_BR_PROB_BASE;
|
||
if (index == 20)
|
||
index = 19;
|
||
hist_br_prob[index]++;
|
||
}
|
||
num_branches++;
|
||
|
||
REG_NOTES (arcptr->branch_insn)
|
||
= gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
|
||
REG_NOTES (arcptr->branch_insn));
|
||
}
|
||
}
|
||
|
||
/* Add a REG_EXEC_COUNT note to the first instruction of this block. */
|
||
if (! binfo->first_insn
|
||
|| GET_RTX_CLASS (GET_CODE (binfo->first_insn)) != 'i')
|
||
{
|
||
/* Block 0 is a fake block representing function entry, and does
|
||
not have a real first insn. The second last block might not
|
||
begin with a real insn. */
|
||
if (i == num_blocks - 1)
|
||
return_label_execution_count = total;
|
||
else if (i != 0 && i != num_blocks - 2)
|
||
abort ();
|
||
}
|
||
else
|
||
{
|
||
REG_NOTES (binfo->first_insn)
|
||
= gen_rtx_EXPR_LIST (REG_EXEC_COUNT, GEN_INT (total),
|
||
REG_NOTES (binfo->first_insn));
|
||
if (i == num_blocks - 1)
|
||
return_label_execution_count = total;
|
||
}
|
||
}
|
||
|
||
/* This should never happen. */
|
||
if (bad_counts)
|
||
warning ("Arc profiling: some arc counts were bad.");
|
||
|
||
if (dump_file)
|
||
{
|
||
fprintf (dump_file, "%d branches\n", num_branches);
|
||
fprintf (dump_file, "%d branches never executed\n",
|
||
num_never_executed);
|
||
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;
|
||
total_num_never_executed += num_never_executed;
|
||
for (i = 0; i < 20; i++)
|
||
total_hist_br_prob[i] += hist_br_prob[i];
|
||
}
|
||
|
||
}
|
||
|
||
/* Initialize a new arc.
|
||
ARCPTR is the empty adj_list this function fills in.
|
||
SOURCE is the block number of the source block.
|
||
TARGET is the block number of the target block.
|
||
INSN is the insn which transfers control from SOURCE to TARGET,
|
||
or zero if the transfer is implicit. */
|
||
|
||
static void
|
||
init_arc (arcptr, source, target, insn)
|
||
struct adj_list *arcptr;
|
||
int source, target;
|
||
rtx insn;
|
||
{
|
||
ARC_TARGET (arcptr) = target;
|
||
ARC_SOURCE (arcptr) = source;
|
||
|
||
ARC_COUNT (arcptr) = 0;
|
||
arcptr->count_valid = 0;
|
||
arcptr->on_tree = 0;
|
||
arcptr->fake = 0;
|
||
arcptr->fall_through = 0;
|
||
arcptr->branch_insn = insn;
|
||
|
||
arcptr->succ_next = bb_graph[source].succ;
|
||
bb_graph[source].succ = arcptr;
|
||
bb_graph[source].succ_count++;
|
||
|
||
arcptr->pred_next = bb_graph[target].pred;
|
||
bb_graph[target].pred = arcptr;
|
||
bb_graph[target].pred_count++;
|
||
}
|
||
|
||
/* This function searches all of the arcs in the program flow graph, and puts
|
||
as many bad arcs as possible onto the spanning tree. Bad arcs include
|
||
fake arcs (needed for setjmp(), longjmp(), exit()) which MUST be on the
|
||
spanning tree as they can't be instrumented. Also, arcs which must be
|
||
split when instrumented should be part of the spanning tree if possible. */
|
||
|
||
static void
|
||
find_spanning_tree (num_blocks)
|
||
int num_blocks;
|
||
{
|
||
int i;
|
||
struct adj_list *arcptr;
|
||
struct bb_info *binfo = &bb_graph[0];
|
||
|
||
/* Fake arcs must be part of the spanning tree, and are always safe to put
|
||
on the spanning tree. Fake arcs will either be a successor of node 0,
|
||
a predecessor of the last node, or from the last node to node 0. */
|
||
|
||
for (arcptr = bb_graph[0].succ; arcptr; arcptr = arcptr->succ_next)
|
||
if (arcptr->fake)
|
||
{
|
||
/* Adding this arc should never cause a cycle. This is a fatal
|
||
error if it would. */
|
||
if (bb_graph[ARC_TARGET (arcptr)].on_tree && binfo->on_tree)
|
||
abort();
|
||
else
|
||
{
|
||
arcptr->on_tree = 1;
|
||
bb_graph[ARC_TARGET (arcptr)].on_tree = 1;
|
||
binfo->on_tree = 1;
|
||
}
|
||
}
|
||
|
||
binfo = &bb_graph[num_blocks-1];
|
||
for (arcptr = binfo->pred; arcptr; arcptr = arcptr->pred_next)
|
||
if (arcptr->fake)
|
||
{
|
||
/* Adding this arc should never cause a cycle. This is a fatal
|
||
error if it would. */
|
||
if (bb_graph[ARC_SOURCE (arcptr)].on_tree && binfo->on_tree)
|
||
abort();
|
||
else
|
||
{
|
||
arcptr->on_tree = 1;
|
||
bb_graph[ARC_SOURCE (arcptr)].on_tree = 1;
|
||
binfo->on_tree = 1;
|
||
}
|
||
}
|
||
/* The only entrace to node zero is a fake arc. */
|
||
bb_graph[0].pred->on_tree = 1;
|
||
|
||
/* Arcs which are crowded at both the source and target should be put on
|
||
the spanning tree if possible, except for fall_throuch arcs which never
|
||
require adding a new block even if crowded, add arcs with the same source
|
||
and dest which must always be instrumented. */
|
||
for (i = 0; i < num_blocks; i++)
|
||
{
|
||
binfo = &bb_graph[i];
|
||
|
||
for (arcptr = binfo->succ; arcptr; arcptr = arcptr->succ_next)
|
||
if (! ((binfo->succ == arcptr && arcptr->succ_next == 0)
|
||
|| (bb_graph[ARC_TARGET (arcptr)].pred
|
||
&& arcptr->pred_next == 0))
|
||
&& ! arcptr->fall_through
|
||
&& ARC_TARGET (arcptr) != i)
|
||
{
|
||
/* This is a crowded arc at both source and target. Try to put
|
||
in on the spanning tree. Can do this if either the source or
|
||
target block is not yet on the tree. */
|
||
if (! bb_graph[ARC_TARGET (arcptr)].on_tree || ! binfo->on_tree)
|
||
{
|
||
arcptr->on_tree = 1;
|
||
bb_graph[ARC_TARGET (arcptr)].on_tree = 1;
|
||
binfo->on_tree = 1;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Clear all of the basic block on_tree bits, so that we can use them to
|
||
create the spanning tree. */
|
||
for (i = 0; i < num_blocks; i++)
|
||
bb_graph[i].on_tree = 0;
|
||
|
||
/* Now fill in the spanning tree until every basic block is on it.
|
||
Don't put the 0 to 1 fall through arc on the tree, since it is
|
||
always cheap to instrument, so start filling the tree from node 1. */
|
||
|
||
for (i = 1; i < num_blocks; i++)
|
||
for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next)
|
||
if (! arcptr->on_tree
|
||
&& ! bb_graph[ARC_TARGET (arcptr)].on_tree)
|
||
{
|
||
fill_spanning_tree (i);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Add arcs reached from BLOCK to the spanning tree if they are needed and
|
||
not already there. */
|
||
|
||
static void
|
||
fill_spanning_tree (block)
|
||
int block;
|
||
{
|
||
struct adj_list *arcptr;
|
||
|
||
expand_spanning_tree (block);
|
||
|
||
for (arcptr = bb_graph[block].succ; arcptr; arcptr = arcptr->succ_next)
|
||
if (! arcptr->on_tree
|
||
&& ! bb_graph[ARC_TARGET (arcptr)].on_tree)
|
||
{
|
||
arcptr->on_tree = 1;
|
||
fill_spanning_tree (ARC_TARGET (arcptr));
|
||
}
|
||
}
|
||
|
||
/* When first visit a block, must add all blocks that are already connected
|
||
to this block via tree arcs to the spanning tree. */
|
||
|
||
static void
|
||
expand_spanning_tree (block)
|
||
int block;
|
||
{
|
||
struct adj_list *arcptr;
|
||
|
||
bb_graph[block].on_tree = 1;
|
||
|
||
for (arcptr = bb_graph[block].succ; arcptr; arcptr = arcptr->succ_next)
|
||
if (arcptr->on_tree && ! bb_graph[ARC_TARGET (arcptr)].on_tree)
|
||
expand_spanning_tree (ARC_TARGET (arcptr));
|
||
|
||
for (arcptr = bb_graph[block].pred;
|
||
arcptr; arcptr = arcptr->pred_next)
|
||
if (arcptr->on_tree && ! bb_graph[ARC_SOURCE (arcptr)].on_tree)
|
||
expand_spanning_tree (ARC_SOURCE (arcptr));
|
||
}
|
||
|
||
/* Perform file-level initialization for branch-prob processing. */
|
||
|
||
void
|
||
init_branch_prob (filename)
|
||
char *filename;
|
||
{
|
||
long len;
|
||
int i;
|
||
|
||
if (flag_test_coverage)
|
||
{
|
||
/* Open an output file for the basic block/line number map. */
|
||
int len = strlen (filename);
|
||
char *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, "w")) == 0)
|
||
pfatal_with_name (data_file);
|
||
|
||
/* Open an output file for the program flow graph. */
|
||
len = strlen (filename);
|
||
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, "w")) == 0)
|
||
pfatal_with_name (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)
|
||
{
|
||
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, "r")) == 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 arcs,
|
||
which is not needed for our purposes. */
|
||
|
||
if (da_file)
|
||
__read_long (&len, da_file, 8);
|
||
}
|
||
|
||
if (profile_arc_flag)
|
||
init_arc_profiler ();
|
||
|
||
total_num_blocks = 0;
|
||
total_num_arcs = 0;
|
||
total_num_arcs_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 (dump_file)
|
||
FILE *dump_file;
|
||
{
|
||
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))
|
||
warning (".da file contents exhausted too early\n");
|
||
/* Should be at end of file now. */
|
||
if (__read_long (&temp, da_file, 8) == 0)
|
||
warning (".da file contents not exhausted\n");
|
||
fclose (da_file);
|
||
}
|
||
}
|
||
|
||
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 arcs: %d\n", total_num_arcs);
|
||
fprintf (dump_file, "Total number of instrumented arcs: %d\n",
|
||
total_num_arcs_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);
|
||
fprintf (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 (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 arc profiling code. */
|
||
|
||
static rtx profiler_label;
|
||
|
||
/* Initialize the profiler_label. */
|
||
|
||
static void
|
||
init_arc_profiler ()
|
||
{
|
||
/* Generate and save a copy of this so it can be shared. */
|
||
char *name = xmalloc (20);
|
||
ASM_GENERATE_INTERNAL_LABEL (name, "LPBX", 2);
|
||
profiler_label = gen_rtx_SYMBOL_REF (Pmode, name);
|
||
}
|
||
|
||
/* Output instructions as RTL to increment the arc execution count. */
|
||
|
||
static void
|
||
output_arc_profiler (arcno, insert_after)
|
||
int arcno;
|
||
rtx insert_after;
|
||
{
|
||
rtx profiler_target_addr
|
||
= (arcno
|
||
? gen_rtx_CONST (Pmode,
|
||
gen_rtx_PLUS (Pmode, profiler_label,
|
||
GEN_INT (LONG_TYPE_SIZE / BITS_PER_UNIT * arcno)))
|
||
: profiler_label);
|
||
enum machine_mode mode = mode_for_size (LONG_TYPE_SIZE, MODE_INT, 0);
|
||
rtx profiler_reg = gen_reg_rtx (mode);
|
||
rtx address_reg = gen_reg_rtx (Pmode);
|
||
rtx mem_ref, add_ref;
|
||
rtx sequence;
|
||
|
||
/* In this case, reload can use explicitly mentioned hard registers for
|
||
reloads. It is not safe to output profiling code between a call
|
||
and the instruction that copies the result to a pseudo-reg. This
|
||
is because reload may allocate one of the profiling code pseudo-regs
|
||
to the return value reg, thus clobbering the return value. So we
|
||
must check for calls here, and emit the profiling code after the
|
||
instruction that uses the return value, if any.
|
||
|
||
??? The code here performs the same tests that reload does so hopefully
|
||
all the bases are covered. */
|
||
|
||
if (SMALL_REGISTER_CLASSES
|
||
&& GET_CODE (insert_after) == CALL_INSN
|
||
&& (GET_CODE (PATTERN (insert_after)) == SET
|
||
|| (GET_CODE (PATTERN (insert_after)) == PARALLEL
|
||
&& GET_CODE (XVECEXP (PATTERN (insert_after), 0, 0)) == SET)))
|
||
{
|
||
rtx return_reg;
|
||
rtx next_insert_after = next_nonnote_insn (insert_after);
|
||
|
||
/* The first insn after the call may be a stack pop, skip it. */
|
||
if (next_insert_after
|
||
&& GET_CODE (next_insert_after) == INSN
|
||
&& GET_CODE (PATTERN (next_insert_after)) == SET
|
||
&& SET_DEST (PATTERN (next_insert_after)) == stack_pointer_rtx)
|
||
next_insert_after = next_nonnote_insn (next_insert_after);
|
||
|
||
if (next_insert_after
|
||
&& GET_CODE (next_insert_after) == INSN)
|
||
{
|
||
if (GET_CODE (PATTERN (insert_after)) == SET)
|
||
return_reg = SET_DEST (PATTERN (insert_after));
|
||
else
|
||
return_reg = SET_DEST (XVECEXP (PATTERN (insert_after), 0, 0));
|
||
|
||
/* Now, NEXT_INSERT_AFTER may be an instruction that uses the
|
||
return value. However, it could also be something else,
|
||
like a CODE_LABEL, so check that the code is INSN. */
|
||
if (next_insert_after != 0
|
||
&& GET_RTX_CLASS (GET_CODE (next_insert_after)) == 'i'
|
||
&& reg_referenced_p (return_reg, PATTERN (next_insert_after)))
|
||
insert_after = next_insert_after;
|
||
}
|
||
}
|
||
|
||
start_sequence ();
|
||
|
||
emit_move_insn (address_reg, profiler_target_addr);
|
||
mem_ref = gen_rtx_MEM (mode, address_reg);
|
||
emit_move_insn (profiler_reg, mem_ref);
|
||
|
||
add_ref = gen_rtx_PLUS (mode, profiler_reg, GEN_INT (1));
|
||
emit_move_insn (profiler_reg, add_ref);
|
||
|
||
/* This is the same rtx as above, but it is not legal to share this rtx. */
|
||
mem_ref = gen_rtx_MEM (mode, address_reg);
|
||
emit_move_insn (mem_ref, profiler_reg);
|
||
|
||
sequence = gen_sequence ();
|
||
end_sequence ();
|
||
emit_insn_after (sequence, insert_after);
|
||
}
|
||
|
||
/* 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, *cfnname;
|
||
rtx table_address;
|
||
enum machine_mode mode = mode_for_size (LONG_TYPE_SIZE, MODE_INT, 0);
|
||
int save_flag_inline_functions = flag_inline_functions;
|
||
|
||
/* It's either already been output, or we don't need it because we're
|
||
not doing profile-arcs. */
|
||
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. */
|
||
start_sequence ();
|
||
|
||
/* 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 = xmalloc (strlen (cfnname) + 5);
|
||
sprintf (name, "%sGCOV",cfnname);
|
||
fnname = get_identifier (name);
|
||
free (name);
|
||
|
||
fndecl = build_decl (FUNCTION_DECL, fnname,
|
||
build_function_type (void_type_node, NULL_TREE));
|
||
DECL_EXTERNAL (fndecl) = 0;
|
||
TREE_PUBLIC (fndecl) = 1;
|
||
DECL_ASSEMBLER_NAME (fndecl) = fnname;
|
||
DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
|
||
current_function_decl = fndecl;
|
||
pushlevel (0);
|
||
make_function_rtl (fndecl);
|
||
init_function_start (fndecl, input_filename, lineno);
|
||
expand_function_start (fndecl, 0);
|
||
|
||
/* Actually generate the code to call __bb_init_func. */
|
||
name = xmalloc (20);
|
||
ASM_GENERATE_INTERNAL_LABEL (name, "LPBX", 0);
|
||
table_address = force_reg (Pmode, gen_rtx_SYMBOL_REF (Pmode, name));
|
||
emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_init_func"), 0,
|
||
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;
|
||
|
||
rest_of_compilation (fndecl);
|
||
|
||
/* Reset flag_inline_functions to its original value. */
|
||
flag_inline_functions = save_flag_inline_functions;
|
||
|
||
if (! quiet_flag)
|
||
fflush (asm_out_file);
|
||
current_function_decl = NULL_TREE;
|
||
|
||
assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl)));
|
||
}
|