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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/38474] compile time explosion in
 dataflow_set_preserve_mem_locs at -O3
Date: Wed, 10 Feb 2021 15:03:58 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D38474

--- Comment #84 from Richard Biener <rguenth at gcc dot gnu.org> ---
So it's the usual (quadratic) culprit:

Samples: 1M of event 'cycles:u', Event count (approx.): 1675893461671=20=20=
=20=20=20=20=20=20=20=20=20
Overhead       Samples  Command  Shared Object     Symbol=20=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20
  20.61%        316521  f951     f951              [.] get_ref_base_and_ext=
ent
  14.42%        221221  f951     f951              [.] (anonymous
namespace)::pass_store_merging::terminate_all_aliasing_chains
   5.77%         88586  f951     f951              [.] special_function_p

I'll see whether I can do some surgery.=