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From: "segher at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/99927] [11 Regression] Maybe wrong code since
 r11-39-gf9e1ea10e657af9f
Date: Tue, 06 Apr 2021 19:59:03 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99927

--- Comment #9 from Segher Boessenkool <segher at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #5)
> But what is wrong is that try_combine has been called at all, because
> (reg:CCZ 17 flags) is used in 3 instructions rather than just one.

That is not a problem; If that were true it just would mean that
added_sets_2 should be set:

  added_sets_2 =3D !dead_or_set_p (i3, i2dest);

But, the flags reg actually *is* dead in i3 (insn 108), it dies in i2
(insn 107):

     (expr_list:REG_DEAD (reg:SI 107)

So something earlier is bad already.=