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From: "tnfchris at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/115120] Bad interaction between ivcanon and
 early break vectorization
Date: Fri, 17 May 2024 07:47:30 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D115120

--- Comment #3 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
That makes sense, though I also wonder how it works for scalar multi exit
loops, IVops has various checks on single exits.

I guess one problem is that the code in IVops that does this uses the exit =
to
determine niters.

But in the case of the multiple exits vector code the vectorizer could have
picked a different exit.

So I guess the question is how do we even tell which one is used or could t=
he
transformation be driven from the PHI nodes themselves instead of an exit.=