[Bug rtl-optimization/69609] block reordering consumes an inordinate amount of time, REE consumes much memory

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69609

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |stevenb.gcc at gmail dot com

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Top offender is now

 df live&initialized regs:  12.06 (21%) usr   0.00 ( 0%) sys  12.10 (21%) wall 
     0 kB ( 0%) ggc
 PRE                     :  15.53 (27%) usr   0.29 (26%) sys  15.83 (27%) wall 
   793 kB ( 0%) ggc

with perf reporting

 11.95%  cc1  cc1                [.] df_live_bb_local_compute(unsigned int)
  6.69%  cc1  cc1                [.] compute_transp(rtx_def const*, int,
simple_
  4.44%  cc1  cc1                [.] df_worklist_dataflow(dataflow*,
bitmap_head
  3.10%  cc1  cc1                [.]
df_simulate_one_insn_forwards(basic_block_d
  2.99%  cc1  cc1                [.] bitmap_set_bit(bitmap_head*, int)

I suspect the DF part is PRE as well.  PRE already has some limiting on
CFG complexity that appearantly doesn't trigger here.  See
gcse_or_cprop_is_too_expensive.  OTOH we still call df_analyze before
checking that (oops?!).