From: adam8157@gmail.com (Adam Lee)
To: kernelnewbies@lists.kernelnewbies.org
Subject: What does %P1 mean in gcc inline assembly?
Date: Mon, 7 Mar 2016 10:51:58 +0800 [thread overview]
Message-ID: <20160307025158.GB1158@rmbp> (raw)
In-Reply-To: <F7866D80-A9FF-4B61-863D-582D6E953C2E@163.com>
On Sat, Mar 05, 2016 at 11:37:21AM +0800, ?? wrote:
>
> On Mar 4, 2016, at 11:59 PM, Dave Tian <dave.jing.tian@gmail.com> wrote:
>
> This ?P? is used to make gcc happy and work.
> Without ?P?, this inline would be interpreted as:
> leal $-512(%esp), %eax
> With ?P?, this inline is the thing we really want:
> leal -512(%esp), %eax
>
> Eventually, my gcc 4.9.2 does not compile with ?P? is missing. I am not
> sure if this is still the case for newer gcc (5/6). But you get the point.
>
> -daveti
>
> Thank you for your detailed answer !
>
> By the way? If someone have the problems alike, I suggest them to write some
> inline assembly and check the compiler?s assembly output.
Didn't get different outputs here, do you have updates?
--
Adam Lee
http://adam8157.info
next prev parent reply other threads:[~2016-03-07 2:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-04 12:36 What does %P1 mean in gcc inline assembly? 张云
2016-03-04 15:59 ` Dave Tian
2016-03-05 3:37 ` 张云
2016-03-07 2:51 ` Adam Lee [this message]
2016-03-07 3:22 ` 回复：Re: " 张云
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