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diff --git a/gcc-4.2.1-5666.3/gcc/tracer.c b/gcc-4.2.1-5666.3/gcc/tracer.c
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-/* The tracer pass for the GNU compiler.
- Contributed by Jan Hubicka, SuSE Labs.
- Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
-
- This file is part of GCC.
-
- GCC is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
-
- GCC is distributed in the hope that it will be useful, but WITHOUT
- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
- License for more details.
-
- You should have received a copy of the GNU General Public License
- along with GCC; see the file COPYING. If not, write to the Free
- Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
-
-/* This pass performs the tail duplication needed for superblock formation.
- For more information see:
-
- Design and Analysis of Profile-Based Optimization in Compaq's
- Compilation Tools for Alpha; Journal of Instruction-Level
- Parallelism 3 (2000) 1-25
-
- Unlike Compaq's implementation we don't do the loop peeling as most
- probably a better job can be done by a special pass and we don't
- need to worry too much about the code size implications as the tail
- duplicates are crossjumped again if optimizations are not
- performed. */
-
-
-#include "config.h"
-#include "system.h"
-#include "coretypes.h"
-#include "tm.h"
-#include "tree.h"
-#include "rtl.h"
-#include "hard-reg-set.h"
-#include "basic-block.h"
-#include "output.h"
-#include "cfglayout.h"
-#include "fibheap.h"
-#include "flags.h"
-#include "timevar.h"
-#include "params.h"
-#include "coverage.h"
-#include "tree-pass.h"
-
-static int count_insns (basic_block);
-static bool ignore_bb_p (basic_block);
-static bool better_p (edge, edge);
-static edge find_best_successor (basic_block);
-static edge find_best_predecessor (basic_block);
-static int find_trace (basic_block, basic_block *);
-static void tail_duplicate (void);
-static void layout_superblocks (void);
-
-/* Minimal outgoing edge probability considered for superblock formation. */
-static int probability_cutoff;
-static int branch_ratio_cutoff;
-
-/* Return true if BB has been seen - it is connected to some trace
- already. */
-
-#define seen(bb) (bb->il.rtl->visited || bb->aux)
-
-/* Return true if we should ignore the basic block for purposes of tracing. */
-static bool
-ignore_bb_p (basic_block bb)
-{
- if (bb->index < NUM_FIXED_BLOCKS)
- return true;
- if (!maybe_hot_bb_p (bb))
- return true;
- return false;
-}
-
-/* Return number of instructions in the block. */
-
-static int
-count_insns (basic_block bb)
-{
- rtx insn;
- int n = 0;
-
- for (insn = BB_HEAD (bb);
- insn != NEXT_INSN (BB_END (bb));
- insn = NEXT_INSN (insn))
- if (active_insn_p (insn))
- n++;
- return n;
-}
-
-/* Return true if E1 is more frequent than E2. */
-static bool
-better_p (edge e1, edge e2)
-{
- if (e1->count != e2->count)
- return e1->count > e2->count;
- if (e1->src->frequency * e1->probability !=
- e2->src->frequency * e2->probability)
- return (e1->src->frequency * e1->probability
- > e2->src->frequency * e2->probability);
- /* This is needed to avoid changes in the decision after
- CFG is modified. */
- if (e1->src != e2->src)
- return e1->src->index > e2->src->index;
- return e1->dest->index > e2->dest->index;
-}
-
-/* Return most frequent successor of basic block BB. */
-
-static edge
-find_best_successor (basic_block bb)
-{
- edge e;
- edge best = NULL;
- edge_iterator ei;
-
- FOR_EACH_EDGE (e, ei, bb->succs)
- if (!best || better_p (e, best))
- best = e;
- if (!best || ignore_bb_p (best->dest))
- return NULL;
- if (best->probability <= probability_cutoff)
- return NULL;
- return best;
-}
-
-/* Return most frequent predecessor of basic block BB. */
-
-static edge
-find_best_predecessor (basic_block bb)
-{
- edge e;
- edge best = NULL;
- edge_iterator ei;
-
- FOR_EACH_EDGE (e, ei, bb->preds)
- if (!best || better_p (e, best))
- best = e;
- if (!best || ignore_bb_p (best->src))
- return NULL;
- if (EDGE_FREQUENCY (best) * REG_BR_PROB_BASE
- < bb->frequency * branch_ratio_cutoff)
- return NULL;
- return best;
-}
-
-/* Find the trace using bb and record it in the TRACE array.
- Return number of basic blocks recorded. */
-
-static int
-find_trace (basic_block bb, basic_block *trace)
-{
- int i = 0;
- edge e;
-
- if (dump_file)
- fprintf (dump_file, "Trace seed %i [%i]", bb->index, bb->frequency);
-
- while ((e = find_best_predecessor (bb)) != NULL)
- {
- basic_block bb2 = e->src;
- if (seen (bb2) || (e->flags & (EDGE_DFS_BACK | EDGE_COMPLEX))
- || find_best_successor (bb2) != e)
- break;
- if (dump_file)
- fprintf (dump_file, ",%i [%i]", bb->index, bb->frequency);
- bb = bb2;
- }
- if (dump_file)
- fprintf (dump_file, " forward %i [%i]", bb->index, bb->frequency);
- trace[i++] = bb;
-
- /* Follow the trace in forward direction. */
- while ((e = find_best_successor (bb)) != NULL)
- {
- bb = e->dest;
- if (seen (bb) || (e->flags & (EDGE_DFS_BACK | EDGE_COMPLEX))
- || find_best_predecessor (bb) != e)
- break;
- if (dump_file)
- fprintf (dump_file, ",%i [%i]", bb->index, bb->frequency);
- trace[i++] = bb;
- }
- if (dump_file)
- fprintf (dump_file, "\n");
- return i;
-}
-
-/* Look for basic blocks in frequency order, construct traces and tail duplicate
- if profitable. */
-
-static void
-tail_duplicate (void)
-{
- fibnode_t *blocks = XCNEWVEC (fibnode_t, last_basic_block);
- basic_block *trace = XNEWVEC (basic_block, n_basic_blocks);
- int *counts = XNEWVEC (int, last_basic_block);
- int ninsns = 0, nduplicated = 0;
- gcov_type weighted_insns = 0, traced_insns = 0;
- fibheap_t heap = fibheap_new ();
- gcov_type cover_insns;
- int max_dup_insns;
- basic_block bb;
-
- if (profile_info && flag_branch_probabilities)
- probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK);
- else
- probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY);
- probability_cutoff = REG_BR_PROB_BASE / 100 * probability_cutoff;
-
- branch_ratio_cutoff =
- (REG_BR_PROB_BASE / 100 * PARAM_VALUE (TRACER_MIN_BRANCH_RATIO));
-
- FOR_EACH_BB (bb)
- {
- int n = count_insns (bb);
- if (!ignore_bb_p (bb))
- blocks[bb->index] = fibheap_insert (heap, -bb->frequency,
- bb);
-
- counts [bb->index] = n;
- ninsns += n;
- weighted_insns += n * bb->frequency;
- }
-
- if (profile_info && flag_branch_probabilities)
- cover_insns = PARAM_VALUE (TRACER_DYNAMIC_COVERAGE_FEEDBACK);
- else
- cover_insns = PARAM_VALUE (TRACER_DYNAMIC_COVERAGE);
- cover_insns = (weighted_insns * cover_insns + 50) / 100;
- max_dup_insns = (ninsns * PARAM_VALUE (TRACER_MAX_CODE_GROWTH) + 50) / 100;
-
- while (traced_insns < cover_insns && nduplicated < max_dup_insns
- && !fibheap_empty (heap))
- {
- basic_block bb = fibheap_extract_min (heap);
- int n, pos;
-
- if (!bb)
- break;
-
- blocks[bb->index] = NULL;
-
- if (ignore_bb_p (bb))
- continue;
- gcc_assert (!seen (bb));
-
- n = find_trace (bb, trace);
-
- bb = trace[0];
- traced_insns += bb->frequency * counts [bb->index];
- if (blocks[bb->index])
- {
- fibheap_delete_node (heap, blocks[bb->index]);
- blocks[bb->index] = NULL;
- }
-
- for (pos = 1; pos < n; pos++)
- {
- basic_block bb2 = trace[pos];
-
- if (blocks[bb2->index])
- {
- fibheap_delete_node (heap, blocks[bb2->index]);
- blocks[bb2->index] = NULL;
- }
- traced_insns += bb2->frequency * counts [bb2->index];
- if (EDGE_COUNT (bb2->preds) > 1
- && can_duplicate_block_p (bb2))
- {
- edge e;
- basic_block old = bb2;
-
- e = find_edge (bb, bb2);
-
- nduplicated += counts [bb2->index];
- bb2 = duplicate_block (bb2, e, bb);
-
- /* Reconsider the original copy of block we've duplicated.
- Removing the most common predecessor may make it to be
- head. */
- blocks[old->index] =
- fibheap_insert (heap, -old->frequency, old);
-
- if (dump_file)
- fprintf (dump_file, "Duplicated %i as %i [%i]\n",
- old->index, bb2->index, bb2->frequency);
- }
- bb->aux = bb2;
- bb2->il.rtl->visited = 1;
- bb = bb2;
- /* In case the trace became infrequent, stop duplicating. */
- if (ignore_bb_p (bb))
- break;
- }
- if (dump_file)
- fprintf (dump_file, " covered now %.1f\n\n",
- traced_insns * 100.0 / weighted_insns);
- }
- if (dump_file)
- fprintf (dump_file, "Duplicated %i insns (%i%%)\n", nduplicated,
- nduplicated * 100 / ninsns);
-
- free (blocks);
- free (trace);
- free (counts);
- fibheap_delete (heap);
-}
-
-/* Connect the superblocks into linear sequence. At the moment we attempt to keep
- the original order as much as possible, but the algorithm may be made smarter
- later if needed. BB reordering pass should void most of the benefits of such
- change though. */
-
-static void
-layout_superblocks (void)
-{
- basic_block end = single_succ (ENTRY_BLOCK_PTR);
- basic_block bb = end->next_bb;
-
- while (bb != EXIT_BLOCK_PTR)
- {
- edge_iterator ei;
- edge e, best = NULL;
- while (end->aux)
- end = end->aux;
-
- FOR_EACH_EDGE (e, ei, end->succs)
- if (e->dest != EXIT_BLOCK_PTR
- && e->dest != single_succ (ENTRY_BLOCK_PTR)
- && !e->dest->il.rtl->visited
- && (!best || EDGE_FREQUENCY (e) > EDGE_FREQUENCY (best)))
- best = e;
-
- if (best)
- {
- end->aux = best->dest;
- best->dest->il.rtl->visited = 1;
- }
- else
- for (; bb != EXIT_BLOCK_PTR; bb = bb->next_bb)
- {
- if (!bb->il.rtl->visited)
- {
- end->aux = bb;
- bb->il.rtl->visited = 1;
- break;
- }
- }
- }
-}
-
-/* Main entry point to this file. FLAGS is the set of flags to pass
- to cfg_layout_initialize(). */
-
-void
-tracer (unsigned int flags)
-{
- if (n_basic_blocks <= NUM_FIXED_BLOCKS + 1)
- return;
-
- cfg_layout_initialize (flags);
- mark_dfs_back_edges ();
- if (dump_file)
- dump_flow_info (dump_file, dump_flags);
- tail_duplicate ();
- layout_superblocks ();
- if (dump_file)
- dump_flow_info (dump_file, dump_flags);
- cfg_layout_finalize ();
-
- /* Merge basic blocks in duplicated traces. */
- cleanup_cfg (CLEANUP_EXPENSIVE);
-}
-
-static bool
-gate_handle_tracer (void)
-{
- return (optimize > 0 && flag_tracer);
-}
-
-/* Run tracer. */
-static unsigned int
-rest_of_handle_tracer (void)
-{
- if (dump_file)
- dump_flow_info (dump_file, dump_flags);
- tracer (0);
- cleanup_cfg (CLEANUP_EXPENSIVE);
- reg_scan (get_insns (), max_reg_num ());
- return 0;
-}
-
-struct tree_opt_pass pass_tracer =
-{
- "tracer", /* name */
- gate_handle_tracer, /* gate */
- rest_of_handle_tracer, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_TRACER, /* tv_id */
- 0, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_dump_func, /* todo_flags_finish */
- 'T' /* letter */
-};
-
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