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cfgcleanup.c (first_pass): New static variable.

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* cfgcleanup.c (first_pass): New static variable.
	(try_forward_edges):  Add work limiting check for threading.
	(try_crossjump_bb):  Add work limiting check for crossjumping.
	(try_optimize_cfg):  Maintain first pass variable.

From-SVN: r76375
This commit is contained in:
Jan Hubicka 2004-01-22 23:33:51 +01:00 • committed by Jan Hubicka
parent b16417d615
commit 7cf240d54c
2 changed files with 28 additions and 2 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2004-01-22 Jan Hubicka <jh@suse.cz>
* cfgcleanup.c (first_pass): New static variable.
(try_forward_edges): Add work limiting check for threading.
(try_crossjump_bb): Add work limiting check for crossjumping.
(try_optimize_cfg): Maintain first pass variable.
2004-01-22 Bob Wilson <bob.wilson@acm.org>
* config/xtensa/xtensa.c (function_arg): Generalize logic so that it

23
gcc/cfgcleanup.c
View file

@ -67,6 +67,8 @@ enum bb_flags
#define FORWARDER_BLOCK_P(BB) (BB_FLAGS (BB) & BB_FORWARDER_BLOCK)
/* Set to true when we are running first pass of try_optimize_cfg loop. */
static bool first_pass;
static bool try_crossjump_to_edge (int, edge, edge);
static bool try_crossjump_bb (int, basic_block);
static bool outgoing_edges_match (int, basic_block, basic_block);
@ -429,6 +431,7 @@ try_forward_edges (int mode, basic_block b)
int counter;
bool threaded = false;
int nthreaded_edges = 0;
bool may_thread = first_pass | (b->flags & BB_DIRTY);
next = e->succ_next;
@ -447,6 +450,7 @@ try_forward_edges (int mode, basic_block b)
{
basic_block new_target = NULL;
bool new_target_threaded = false;
may_thread |= target->flags & BB_DIRTY;
if (FORWARDER_BLOCK_P (target)
&& target->succ->dest != EXIT_BLOCK_PTR)
@ -459,7 +463,7 @@ try_forward_edges (int mode, basic_block b)
/* Allow to thread only over one edge at time to simplify updating
of probabilities. */
else if (mode & CLEANUP_THREADING)
else if ((mode & CLEANUP_THREADING) && may_thread)
{
edge t = thread_jump (mode, e, target);
if (t)
@ -1573,6 +1577,12 @@ try_crossjump_bb (int mode, basic_block bb)
If there is a match, we'll do it the other way around. */
if (e == fallthru)
continue;
/* If nothing changed since the last attempt, there is nothing
we can do. */
if (!first_pass
&& (!(e->src->flags & BB_DIRTY)
&& !(fallthru->src->flags & BB_DIRTY)))
continue;
if (try_crossjump_to_edge (mode, e, fallthru))
{
@ -1615,6 +1625,13 @@ try_crossjump_bb (int mode, basic_block bb)
if (e->src->index > e2->src->index)
continue;
/* If nothing changed since the last attempt, there is nothing
we can do. */
if (!first_pass
&& (!(e->src->flags & BB_DIRTY)
&& !(e2->src->flags & BB_DIRTY)))
continue;
if (try_crossjump_to_edge (mode, e, e2))
{
changed = true;
@ -1644,11 +1661,12 @@ try_optimize_cfg (int mode)
FOR_EACH_BB (bb)
update_forwarder_flag (bb);
if (mode & CLEANUP_UPDATE_LIFE)
if (mode & (CLEANUP_UPDATE_LIFE | CLEANUP_CROSSJUMP | CLEANUP_THREADING))
clear_bb_flags ();
if (! (* targetm.cannot_modify_jumps_p) ())
{
first_pass = true;
/* Attempt to merge blocks as made possible by edge removal. If
a block has only one successor, and the successor has only
one predecessor, they may be combined. */
@ -1824,6 +1842,7 @@ try_optimize_cfg (int mode)
#endif
changed_overall |= changed;
first_pass = false;
}
while (changed);
}