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From: caiyinyu <caiyinyu@loongson.cn>
To: Wilco Dijkstra <Wilco.Dijkstra@arm.com>, Xi Ruoyao <xry111@xry111.site>
Cc: 'GNU C Library' <libc-alpha@sourceware.org>
Subject: Re: [PATCH v2 0/5] linux: Avoid va_list for generic syscall wrappers if possible
Date: Fri, 7 Apr 2023 15:31:19 +0800	[thread overview]
Message-ID: <a1c5bcf1-dd52-3377-c349-67ffb57b3744@loongson.cn> (raw)
In-Reply-To: <PAWPR08MB89822CB484CCE39EFD7FFD4183909@PAWPR08MB8982.eurprd08.prod.outlook.com>


在 2023/4/5 下午9:19, Wilco Dijkstra 写道:
> 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?

Thanks.

The patch is dropped and we will go with generic code.




>
> Cheers,
> Wilco


  parent reply	other threads:[~2023-04-07  7:31 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-05 13:19 Wilco Dijkstra
2023-04-05 14:04 ` Adhemerval Zanella Netto
2023-04-07  7:31 ` caiyinyu [this message]
  -- 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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