------- Comment #1 from abel at gcc dot gnu dot org 2009-12-24 08:32 -------
Here, we broke pipelining of outer loops when optimizing the scheduler core.
The problems analyzed by Alexander are simple though. First, when testing
whether a loop is considered for pipelining, I decided to play safe and also
check pipelining_p in addition to the flag in the aux loop data that was
designed specially for this. Naturally, when we then disabled pipelining_p for
rescheduling pipelined loops, this broke, so to fix it we just need to stop
checking for pipelining_p. The second problem is that we use the
last_added_blocks vector when adding blocks to the region, and we failed to
initialize it correctly for the case of moving preheader blocks from an inner
loop to an outer loop when we have added the vector. Also easily fixed via
correctly initializing the vector.
Again, we would ask someone with access to ppc/ppc64 to test this patch as a
part of the combined patch with fixes for all sel-sched bugs, when our testing
will be completed.
This patch also fixes PR39453.
* sel-sched-ir.c (considered_for_pipelining_p): Do not test
for pipelining_p.
(sel_add_loop_preheaders): Add preheader to last_added_blocks.
---
gcc/sel-sched-ir.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
index 2469822..3c2989a 100644
--- a/gcc/sel-sched-ir.c
+++ b/gcc/sel-sched-ir.c
@@ -5825,7 +5825,7 @@ considered_for_pipelining_p (struct loop *loop)
latch. We can't use header here, because this header could be
just removed preheader and it will give us the wrong region number.
Latch can't be used because it could be in the inner loop too. */
- if (LOOP_MARKED_FOR_PIPELINING_P (loop) && pipelining_p)
+ if (LOOP_MARKED_FOR_PIPELINING_P (loop))
{
int rgn = CONTAINING_RGN (loop->latch->index);
@@ -5974,7 +5974,10 @@ sel_add_loop_preheaders (void)
for (i = 0;
VEC_iterate (basic_block, preheader_blocks, i, bb);
i++)
+ {
+ VEC_safe_push (basic_block, heap, last_added_blocks, bb);
sel_add_bb (bb);
+ }
VEC_free (basic_block, heap, preheader_blocks);
}
--
abel at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |abel at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42246
