sched: Remove debug counter sched_block

Currently the debug counter sched_block doesn't work well
since we create dependencies for some insns and those
dependencies are expected to be resolved during scheduling
insns but they can get skipped once we are skipping some
block while respecting sched_block debug counter.

For example, for the below test case:
--
int a, b, c, e, f;
float d;

void
g ()
{
  float h, i[1];
  for (; f;)
    if (c)
      {
	d *e;
	if (b)
	  {
	    float *j = i;
	    j[0] = 0;
	  }
	h = d;
      }
  if (h)
    a = i[0];
}
--
ICE occurs with option "-O2 -fdbg-cnt=sched_block:1".

As the discussion in [1], it seems that we think this debug
counter is useless and can be removed.  It's also implied
that if it's useful and used often, the above issue should
have been cared about and resolved earlier.  So this patch
is to remove this debug counter.

[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-November/635852.html

gcc/ChangeLog:

	* dbgcnt.def (sched_block): Remove.
	* sched-rgn.cc (schedule_region): Remove the support of debug count
	sched_block.
This commit is contained in:
Kewen Lin 2023-12-20 21:21:54 -06:00
parent 4d9e0f3f21
commit ef259ebeb3
2 changed files with 6 additions and 14 deletions

View File

@ -198,7 +198,6 @@ DEBUG_COUNTER (pre_insn)
DEBUG_COUNTER (prefetch)
DEBUG_COUNTER (registered_jump_thread)
DEBUG_COUNTER (sched2_func)
DEBUG_COUNTER (sched_block)
DEBUG_COUNTER (sched_breakdep)
DEBUG_COUNTER (sched_func)
DEBUG_COUNTER (sched_insn)

View File

@ -3198,20 +3198,13 @@ schedule_region (int rgn)
current_sched_info->queue_must_finish_empty = current_nr_blocks == 1;
curr_bb = first_bb;
if (dbg_cnt (sched_block))
{
int saved_last_basic_block = last_basic_block_for_fn (cfun);
int saved_last_basic_block = last_basic_block_for_fn (cfun);
schedule_block (&curr_bb, bb_state[first_bb->index]);
gcc_assert (EBB_FIRST_BB (bb) == first_bb);
sched_rgn_n_insns += sched_n_insns;
realloc_bb_state_array (saved_last_basic_block);
save_state_for_fallthru_edge (last_bb, curr_state);
}
else
{
sched_rgn_n_insns += rgn_n_insns;
}
schedule_block (&curr_bb, bb_state[first_bb->index]);
gcc_assert (EBB_FIRST_BB (bb) == first_bb);
sched_rgn_n_insns += sched_n_insns;
realloc_bb_state_array (saved_last_basic_block);
save_state_for_fallthru_edge (last_bb, curr_state);
/* Clean up. */
if (current_nr_blocks > 1)