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From: "juzhe.zhong at rivai dot ai" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/113134] gcc does not version loops with early break
 conditions that don't have side-effects
Date: Thu, 28 Dec 2023 03:55:16 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113134

--- Comment #5 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
(In reply to Tamar Christina from comment #4)
> (In reply to JuzheZhong from comment #3)
> > I guess this code is just disabling partial vector for length for now.
> >=20
> > And need me to test and port this part for length in the followup patch=
es.
> >=20
> > Am I right ?
>=20
> Yeah, it needed to safely not allow it through for now. Once implemented=
=20
> you'll hit an assert in vectorizable_live_operations where you need to
> provide a way to also get the first active element from a vector.

So for a length target, I enable cbranch optab but no vcond_mask_len optab.
Will it behavior wrong ?

Another question is could you give me more hints about
vectorizable_live_operation?

I thought vectorizable_live_operation is doing extract last active element,
I didn't see extract first active element.=