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From: Christian Svensson <blue@cmd.nu>
To: clg@kaod.org
Cc: Christian Svensson <bluecmd@google.com>,
	 "openbmc @ lists . ozlabs . org" <openbmc@lists.ozlabs.org>,
	Joel Stanley <joel@jms.id.au>,
	andrew@aj.id.au
Subject: Re: [PATCH] qemu: aspeed_timer: Use signed muldiv for timer resets
Date: Mon, 12 Nov 2018 19:45:10 +0100	[thread overview]
Message-ID: <CADiuDAQ1mjh56ibSd+tNq2NFiJFtLcAfyoC8fdd=y+4Mu+jD6w@mail.gmail.com> (raw)
In-Reply-To: <21acbd66-c75c-d5e3-fcfb-fa75421a7879@kaod.org>

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Hi
On Mon, Nov 12, 2018 at 7:37 PM Cédric Le Goater <clg@kaod.org> wrote:
> isn't QEMU using the helpers from :
>
>         include/qemu/host-utils.h
>
> which do about the same ?

Multdiv64 only takes unsigned ints, and while I'm not familiar with the
details of how that propagates to the division, it seems to result in
nonsensical values for negative inputs.
Before copying this logic here I looked for an equivalent for signed ints
but did not find any suitable one, and the expansion seemed simple enough.

You can see more details in
https://github.com/openbmc/qemu/issues/14#issuecomment-437692215.

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  reply	other threads:[~2018-11-12 18:45 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-12 14:21 [PATCH] qemu: aspeed_timer: Use signed muldiv for timer resets Christian Svensson
2018-11-12 18:37 ` Cédric Le Goater
2018-11-12 18:45   ` Christian Svensson [this message]
2018-11-13  0:27     ` Andrew Jeffery
2018-11-13  8:58       ` Christian Svensson
2019-01-11 12:30         ` Christian Svensson
2019-01-14  2:14           ` Andrew Jeffery
2019-01-14  7:18             ` Christian Svensson
2019-02-11 22:52               ` Andrew Jeffery

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