void
loop_optimizer_init (unsigned flags)
{
timevar_push (TV_LOOP_INIT);
if (!current_loops)
{
gcc_assert (!(cfun->curr_properties & PROP_loops));
/* Find the loops. */
current_loops = flow_loops_find (NULL);
}
else
{
bool recorded_exits = loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS);
bool needs_fixup = loops_state_satisfies_p (LOOPS_NEED_FIXUP);
gcc_assert (cfun->curr_properties & PROP_loops);
/* Ensure that the dominators are computed, like flow_loops_find does. */
calculate_dominance_info (CDI_DOMINATORS);
#ifdef ENABLE_CHECKING
if (!needs_fixup)
verify_loop_structure ();
#endif
/* Clear all flags. */
if (recorded_exits)
release_recorded_exits ();
loops_state_clear (~0U);
if (needs_fixup)
{
/* Apply LOOPS_MAY_HAVE_MULTIPLE_LATCHES early as fix_loop_structure
re-applies flags. */
loops_state_set (flags & LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
fix_loop_structure (NULL);
}
}
/* Apply flags to loops. */
apply_loop_flags (flags);
/* Dump loops. */
flow_loops_dump (dump_file, NULL, 1);
#ifdef ENABLE_CHECKING
verify_loop_structure ();
#endif
timevar_pop (TV_LOOP_INIT);
}
void
loop_optimizer_finalize (void)
{
struct loop *loop;
basic_block bb;
timevar_push (TV_LOOP_FINI);
if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
release_recorded_exits ();
free_numbers_of_iterations_estimates ();
/* If we should preserve loop structure, do not free it but clear
flags that advanced properties are there as we are not preserving
that in full. */
if (cfun->curr_properties & PROP_loops)
{
loops_state_clear (LOOP_CLOSED_SSA
| LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS
| LOOPS_HAVE_PREHEADERS
| LOOPS_HAVE_SIMPLE_LATCHES
| LOOPS_HAVE_FALLTHRU_PREHEADERS);
loops_state_set (LOOPS_MAY_HAVE_MULTIPLE_LATCHES);
goto loop_fini_done;
}
gcc_assert (current_loops != NULL);
FOR_EACH_LOOP (loop, 0)
free_simple_loop_desc (loop);
/* Clean up. */
flow_loops_free (current_loops);
ggc_free (current_loops);
current_loops = NULL;
FOR_ALL_BB_FN (bb, cfun)
{
bb->loop_father = NULL;
}
loop_fini_done:
timevar_pop (TV_LOOP_FINI);
}
unsigned
fix_loop_structure (bitmap changed_bbs)
{
basic_block bb;
int record_exits = 0;
struct loop *loop;
unsigned old_nloops, i;
timevar_push (TV_LOOP_INIT);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "fix_loop_structure: fixing up loops for function\n");
/* We need exact and fast dominance info to be available. */
gcc_assert (dom_info_state (CDI_DOMINATORS) == DOM_OK);
if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
{
release_recorded_exits (cfun);
record_exits = LOOPS_HAVE_RECORDED_EXITS;
}
/* Remember the depth of the blocks in the loop hierarchy, so that we can
recognize blocks whose loop nesting relationship has changed. */
if (changed_bbs)
FOR_EACH_BB_FN (bb, cfun)
bb->aux = (void *) (size_t) loop_depth (bb->loop_father);
/* Remove the dead loops from structures. We start from the innermost
loops, so that when we remove the loops, we know that the loops inside
are preserved, and do not waste time relinking loops that will be
removed later. */
FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
{
/* Detect the case that the loop is no longer present even though
it wasn't marked for removal.
??? If we do that we can get away with not marking loops for
removal at all. And possibly avoid some spurious removals. */
if (loop->header
&& bb_loop_header_p (loop->header))
continue;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "fix_loop_structure: removing loop %d\n",
loop->num);
while (loop->inner)
{
struct loop *ploop = loop->inner;
flow_loop_tree_node_remove (ploop);
flow_loop_tree_node_add (loop_outer (loop), ploop);
}
/* Remove the loop. */
if (loop->header)
loop->former_header = loop->header;
else
gcc_assert (loop->former_header != NULL);
loop->header = NULL;
flow_loop_tree_node_remove (loop);
}
/* Remember the number of loops so we can return how many new loops
flow_loops_find discovered. */
old_nloops = number_of_loops (cfun);
/* Re-compute loop structure in-place. */
flow_loops_find (current_loops);
/* Mark the blocks whose loop has changed. */
if (changed_bbs)
{
FOR_EACH_BB_FN (bb, cfun)
{
if ((void *) (size_t) loop_depth (bb->loop_father) != bb->aux)
bitmap_set_bit (changed_bbs, bb->index);
bb->aux = NULL;
}
}
/* Finally free deleted loops. */
bool any_deleted = false;
FOR_EACH_VEC_ELT (*get_loops (cfun), i, loop)
if (loop && loop->header == NULL)
{
if (dump_file
&& ((unsigned) loop->former_header->index
< basic_block_info_for_fn (cfun)->length ()))
{
basic_block former_header
= BASIC_BLOCK_FOR_FN (cfun, loop->former_header->index);
/* If the old header still exists we want to check if the
original loop is re-discovered or the old header is now
part of a newly discovered loop.
In both cases we should have avoided removing the loop. */
if (former_header == loop->former_header)
{
if (former_header->loop_father->header == former_header)
fprintf (dump_file, "fix_loop_structure: rediscovered "
"removed loop %d as loop %d with old header %d\n",
loop->num, former_header->loop_father->num,
former_header->index);
else if ((unsigned) former_header->loop_father->num
>= old_nloops)
fprintf (dump_file, "fix_loop_structure: header %d of "
"removed loop %d is part of the newly "
"discovered loop %d with header %d\n",
former_header->index, loop->num,
former_header->loop_father->num,
former_header->loop_father->header->index);
}
}
(*get_loops (cfun))[i] = NULL;
flow_loop_free (loop);
any_deleted = true;
}
/* If we deleted loops then the cached scalar evolutions refering to
those loops become invalid. */
if (any_deleted && scev_initialized_p ())
scev_reset_htab ();
loops_state_clear (LOOPS_NEED_FIXUP);
/* Apply flags to loops. */
apply_loop_flags (current_loops->state | record_exits);
checking_verify_loop_structure ();
timevar_pop (TV_LOOP_INIT);
return number_of_loops (cfun) - old_nloops;
}
