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From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/98782] [11/12 Regression] Bad interaction
 between IPA frequences and IRA resulting in spills due to changes in BB
 frequencies
Date: Fri, 10 Dec 2021 11:36:38 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D98782

--- Comment #22 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
We discussed with Richard the option to biass the IRA spilling heuristics to
spill into blocks containing calls (since they are slow anyway) bypassing s=
ome
of the guessed frequencies.

Thinking on it, perhaps I should note that I believe that even with profile
feedback we seem to have IRA problem (it used to be possible to get faster =
code
w/o -fprofile-use then with), so the default heuristics seems to be somehow
misbehaving. With current guessed profile the frequency of BB containing the
recursive call is about 0.9, while reality is about 0.99 which is quite clo=
se.=