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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/113441] [14 Regression] Fail to fold the last
 element with multiple loop
Date: Tue, 23 Jan 2024 12:50:41 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113441

--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Tamar Christina from comment #17)
> Ok, bisected to
>=20
> g:2efe3a7de0107618397264017fb045f237764cc7 is the first bad commit
> commit 2efe3a7de0107618397264017fb045f237764cc7
> Author: Hao Liu <hliu@os.amperecomputing.com>
> Date:   Wed Dec 6 14:52:19 2023 +0800
>=20
>     tree-optimization/112774: extend the SCEV CHREC tree with a nonwrappi=
ng
> flag
>=20
> Before this commit we were unable to analyse the stride of the access.
> After this niters seems to estimate the loop trip count at 4 and after th=
at
> the logs diverge enormously.

Hum, but that's backward and would match to what I said in comment#2 - we
should get better code with that.

Juzhe - when you revert the above ontop of trunk does the generated code
look better for Risc-V?=