From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: libc-alpha@sourceware.org,
Wilco Dijkstra <Wilco.Dijkstra@arm.com>,
"H . J . Lu" <hjl.tools@gmail.com>,
Noah Goldstein <goldstein.w.n@gmail.com>
Subject: Re: [PATCH 00/12] Remove bcopy and bzero optimizations
Date: Tue, 22 Feb 2022 12:40:02 -0300 [thread overview]
Message-ID: <85c89014-39c2-8a19-a7fa-6d32ac0f2bfc@linaro.org> (raw)
In-Reply-To: <20220221163904.GL2692478@arm.com>
On 21/02/2022 13:39, Szabolcs Nagy wrote:
> The 02/10/2022 16:58, Adhemerval Zanella via Libc-alpha wrote:
>> Both symbols are marked as legacy in POSIX.1-2001 and removed on
>> POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE
>> or _DEFAULT_SOURCE.
>>
>> Most architectures just route bcopy/bzero to internal memmove/memset
>> implementation, however some do implement iFUNC variants when memset
>> or memmove are also provided through iFUNC.
>>
>> However, gcc already replaces bcopy with a memmove and bzero with memset
>> on default configuration (to actually get a bstring libc call the code
>> requires to omit string.h inclusion and built with --fno-builtin), so
>> it is highly unlikely programs are actually calling libc bcopy or
>> bzero symbols.
> ...
>> So there is point in keeping such optimization.
>>
>> Adhemerval Zanella (12):
>> ia64: Remove bcopy
>> powerpc: Remove bcopy optimizations
>> i386: Remove bcopy optimizations
>> x86_64: Remove bcopy optimizations
>> alpha: Remove bzero optimization
>> ia64: Remove bzero optimization
>> Remove bzero optimization
>> powerpc: Remove powerpc32 bzero optimizations
>> powerpc: Remove powerpc64 bzero optimizations
>> s390: Remove bzero optimizations
>> i686: Remove bzero optimizations
>> x86_64: Remove bzero optimizations
>
> i see this does not affect aarch64, but i agree with the principle.
>
> (there was a comment about the x86 bzero code that if __memsetzero
> is accepted then it's easier to rename the bzero optimization instead
> of removing and readding.)
I will exclude the last patch that touches x86_64 and commit the rest.
From last discussions on both maillist and weekly we still need to
get consensus on __memsetzero addition.
prev parent reply other threads:[~2022-02-22 15:40 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-10 19:58 Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 01/12] ia64: Remove bcopy Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 02/12] powerpc: Remove bcopy optimizations Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 03/12] i386: " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 04/12] x86_64: " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 05/12] alpha: Remove bzero optimization Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 06/12] ia64: " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 07/12] " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 08/12] powerpc: Remove powerpc32 bzero optimizations Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 09/12] powerpc: Remove powerpc64 " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 10/12] s390: Remove " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 11/12] i686: " Adhemerval Zanella
2022-02-10 19:58 ` [PATCH 12/12] x86_64: " Adhemerval Zanella
2022-02-14 14:29 ` [PATCH 00/12] Remove bcopy and " Florian Weimer
2022-02-14 14:41 ` Adhemerval Zanella
2022-02-21 16:39 ` Szabolcs Nagy
2022-02-22 15:40 ` Adhemerval Zanella [this message]
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