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From: "krebbel at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/94613] combine: Wrong code due to splitting a
 simplified IF_THEN_ELSE
Date: Thu, 16 Apr 2020 07:37:47 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94613

--- Comment #5 from Andreas Krebbel <krebbel at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #3)
> Why is it not correct to split the insn the way you describe?  I see noth=
ing
> wrong with that - the use of r115 is still under r110 =3D=3D 0.  Is the i=
ssue
> that r115 is re-used and r115 has more than a single use?

Yes that's what it appeared to me in the original testcase but I have just
noticed that auto-reduction broke it.  In the reduced testcase r115 dies in
INSN 36 so it isn't useful right now. I agree that the splitting is legal in
that case.=