From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dibyendu Majumdar <mobile@majumdar.org.uk>
Subject: Re: [RFC v0 0/4] Give a type to constants too
Date: Fri, 11 Aug 2017 13:20:38 +0100
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To: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Christopher Li <sparse@chrisli.org>, Linus Torvalds <torvalds@linux-foundation.org>, Sparse Mailing-list <linux-sparse@vger.kernel.org>, Jeff Garzik <jeff@garzik.org>, Pekka Enberg <penberg@kernel.org>

Hi Luc,

On 11 August 2017 at 12:49, Luc Van Oostenryck
<luc.vanoostenryck@gmail.com> wrote:
> On Fri, Aug 11, 2017 at 11:28:23AM +0100, Dibyendu Majumdar wrote:
>> On 10 August 2017 at 23:34, Luc Van Oostenryck
>> <luc.vanoostenryck@gmail.com> wrote:
>> > * the OP_PUSH instructions do a perfect job of giving a type to functions
>> >   arguments
>> > * the OP_PUSH instructions also nicely abstract away the *operation* of
>> >   argument passing that all architectures have. It's a good thing.
>> >
>>
>> It is true that OP_PUSH instructions resolved the issue I was having.
>> However there is something odd about them as they are not really
>> instructions in the instruction stream, are they? They get added as
>> arguments to the OP_CALL instruction. The solution works great though.
>
> Yes, they are somehow odd. I'm not totally sure by what you exactly
> mean by "in the instruction stream", though.
>
> Let's use an example:
>         fun(1, a)
>
> Currently it's linearized as:
>         call    fun, 1, a
>
> The first version of the patch gave:
>         arg     %r1, $1
>         arg     %r2, a
>         call    fun, %r1, %r2
>
> The current version gives:
>         push    $1
>         push    a
>         call    fun
> which is very much like a lot of functions really work.

I was mistaken - I think they do appear in the instruction stream. I
thought they didn't because we kind of ignore them - and only look at
them as part of the OP_CALL arguments.

Regards
Dibyendu