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Subject: Re: [RFC v1 0/2] Use -fno-delete-null-pointer-checks to build glibc
From: Xi Ruoyao <xry111@xry111.site>
To: Alejandro Colomar <alx@kernel.org>, libc-alpha@sourceware.org
Cc: Florian Weimer <fweimer@redhat.com>, Sam James <sam@gentoo.org>, Richard
	Biener <rguenth@gcc.gnu.org>, Andrew Pinski <apinski@marvell.com>
Date: Tue, 11 Jul 2023 21:22:41 +0800
In-Reply-To: <20230711131105.19203-1-alx@kernel.org>
References: <20230711131105.19203-1-alx@kernel.org>
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On Tue, 2023-07-11 at 15:11 +0200, Alejandro Colomar wrote:
> Florian reported that there's -fno-delete-null-pointer-checks to tell
> the compiler to not optimize, and only warn about incorrect uses of null
> pointers.

One potential problem is -fno-delete-null-pointer-checks not only
disables optimizations based on __nonnull, but also disables the
optimizations based on other provable non-null pointer values.  So maybe
we should run a benchmark to see if there is some severe degradation, if
there is any we may fix it by moving null checks away from hot paths.=20

--=20
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University