From: David Brown <david.brown@hesbynett.no>
To: gcc-help@gcc.gnu.org
Subject: Re: Odd error with the "X" inline assembly constraint
Date: Mon, 8 Jan 2024 19:39:39 +0100 [thread overview]
Message-ID: <unhfhb$11ka$1@ciao.gmane.io> (raw)
In-Reply-To: <20240107183235.GH19790@gate.crashing.org>
On 07/01/2024 19:32, Segher Boessenkool wrote:
> On Sun, Jan 07, 2024 at 06:04:23PM +0800, LIU Hao wrote:
>> 在 2024/1/6 2:46, Segher Boessenkool 写道:
>>> The C constraint means "Any operand whatsoever is allowed." Here you
>>> are saying to use it both as input and as output, and GCC does not know
>>> how to reload wherever it chose to put it.
>>
>> Would you mind elaborating a bit more? On x86 and x86-64 it's almost always
>> the case that an expression can be used as either a source or a destination.
>
> This is just GCC internals. The compiler will never look at the
> template string in an asm at all, anyway.
>
> I don't know why exactly you get the error. Make a compilable
> reproducer, file a bug (<https://gcc.gnu.org/bugs.html>), it sounds like
> something we can improve :-)
>
I've filed it :
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113280>
I don't know if this is something that the developer will want to spend
much time on, but it might appeal to someone's curiosity!
David
next prev parent reply other threads:[~2024-01-08 18:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-05 16:30 David Brown
2024-01-05 17:53 ` LIU Hao
2024-01-05 18:46 ` Segher Boessenkool
2024-01-07 10:04 ` LIU Hao
2024-01-07 15:26 ` David Brown
2024-01-07 18:32 ` Segher Boessenkool
2024-01-08 18:39 ` David Brown [this message]
2024-01-07 15:10 ` David Brown
2024-01-07 18:24 ` Segher Boessenkool
2024-01-08 18:48 ` David Brown
2024-01-07 23:18 ` Marc Glisse
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