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From: "marc.glisse at normalesup dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/52381] asm goto output operands diagnostics
Date: Mon, 27 Feb 2012 21:13:00 -0000	[thread overview]
Message-ID: <bug-52381-4-kGyYfoMkmE@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-52381-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52381

--- Comment #2 from Marc Glisse <marc.glisse at normalesup dot org> 2012-02-27 21:08:44 UTC ---
(In reply to comment #1)
> I don't think asm goto was designed to contain more than a computed jump
> instruction.  And I don't know how reliably we could allocate registers
> for outputs on the multiple outgoing edges.
> 
> So, it's definitely by design.

Note that if output was only reliable on the fall-through path, it would
already be useful. It may not have to be all-edges-or-nothing (or it may have
to, I don't know enough). Although that could be confusing...

> Confirmed for the diagnostic issue.

Thanks. While I am asking, I guess that since asm goto involves control flow it
never gets reordered (as opposed to regular asm), but if someone feels like
adding a sentence with this guarantee to the doc it would be helpful too.


  parent reply	other threads:[~2012-02-27 21:09 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-25 13:07 [Bug c/52381] New: asm goto output operands marc.glisse at normalesup dot org
2012-02-27  9:24 ` [Bug c/52381] asm goto output operands diagnostics rguenth at gcc dot gnu.org
2012-02-27 21:13 ` marc.glisse at normalesup dot org [this message]
2013-01-10 13:49 ` timo.kreuzer at reactos dot org
2013-01-10 14:13 ` schwab@linux-m68k.org
2013-01-11 14:56 ` timo.kreuzer at reactos dot org
2023-01-25 22:27 ` pinskia at gcc dot gnu.org

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