From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: Xi Ruoyao <xry111@xry111.site>
Cc: 'GNU C Library' <libc-alpha@sourceware.org>,
"caiyinyu@loongson.cn" <caiyinyu@loongson.cn>
Subject: Re: [PATCH v2 0/5] linux: Avoid va_list for generic syscall wrappers if possible
Date: Wed, 5 Apr 2023 13:19:29 +0000 [thread overview]
Message-ID: <PAWPR08MB89822CB484CCE39EFD7FFD4183909@PAWPR08MB8982.eurprd08.prod.outlook.com> (raw)
Hi,
> Maybe we can use a custom C implementation (like RISC-V) as well. But
> strictly speaking the RISC-V syscall.c is invoking undefined behavior
> (like my proposal) so I agree with assembly here.
How does assembly code not invoke the exact same undefined behaviour?
In both cases you rely on variable arguments being passed in the same
way as integer args - this is true in many ABIs. The goal is to avoid introducing
unnecessary assembly and use generic implementations where possible.
So if that C version works as well as assembler on LoongArch and assuming
that bare syscall() performance is essential, then why not use it?
Cheers,
Wilco
next reply other threads:[~2023-04-05 13:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-05 13:19 Wilco Dijkstra [this message]
2023-04-05 14:04 ` Adhemerval Zanella Netto
2023-04-07 7:31 ` caiyinyu
-- strict thread matches above, loose matches on Subject: below --
2023-04-04 10:12 Wilco Dijkstra
2023-03-25 14:08 Xi Ruoyao
2023-03-27 14:04 ` Carlos O'Donell
2023-03-27 14:44 ` Xi Ruoyao
2023-03-27 14:45 ` Xi Ruoyao
2023-03-27 14:51 ` Xi Ruoyao
2023-04-04 1:25 ` caiyinyu
2023-04-04 12:12 ` Xi Ruoyao
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