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From: "segher at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/107172] [13 Regression] wrong code with "-O1 -ftree-vrp"
 on x86_64-linux-gnu since r13-1268-g8c99e307b20c502e
Date: Tue, 11 Oct 2022 20:26:23 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107172

--- Comment #16 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Hi Roger,

(In reply to Roger Sayle from comment #15)
> Yes, a COMPARE rtx can be used to set various flags on x86, but many other
> operations also legitimately set and/or use MODE_CC, often in a parallel
> with the primary operation.

*Any* MODE_CC setter sets the flags as-if from a compare.  This is what
MODE_CC *is*.

Setting something as ne:CC and then using it as somethingelse:CC has no
defined meaning.=