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From: Florian Weimer <fweimer@redhat.com>
To: Jeff Law via Gcc <gcc@gcc.gnu.org>
Cc: Paul Koning <paulkoning@comcast.net>,
	 Iain Sandoe <iain@sandoe.co.uk>,
	Jeff Law <jeffreyalaw@gmail.com>
Subject: Re: Help with an ABI peculiarity
Date: Mon, 10 Jan 2022 09:38:32 +0100	[thread overview]
Message-ID: <877db80yuv.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <6238c748-c7f3-159b-0464-2175eb6d1b0a@gmail.com> (Jeff Law via Gcc's message of "Sat, 8 Jan 2022 09:35:52 -0700")

* Jeff Law via Gcc:

> Most targets these days use registers for parameter passing and
> obviously we can run out of registers on all of them.  The key
> property is the size/alignment of the argument differs depending on if
> it's pass in a register (get promoted) or passed in memory (not
> promoted).  I'm not immediately aware of another ABI with that
> feature.  Though I haven't really gone looking.

I think what AArch64 Darwin does is not compatible with a GCC extension
that allows calling functions defined with a prototype without it (for
pre-ISO-C compatibility).  Given that, anyone defining an ABI in
parallel with a GCC implementation probably has paused, reconsidered
what they were doing, and adjusted the ABI for K&R compatibility.

Thanks,
Florian


  reply	other threads:[~2022-01-10  8:38 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-07 21:06 Iain Sandoe
2022-01-07 21:55 ` Paul Koning
2022-01-08 16:35   ` Jeff Law
2022-01-10  8:38     ` Florian Weimer [this message]
2022-01-10 13:27       ` Iain Sandoe
2022-01-10 13:46         ` Florian Weimer
2022-01-11 12:53         ` Eric Gallager
2022-01-11 11:57       ` Richard Earnshaw
2022-01-10 10:46 ` Richard Sandiford
2022-01-10 13:06   ` Iain Sandoe
2022-01-20 22:32     ` Richard Sandiford
2022-01-21 11:19       ` Iain Sandoe
2022-01-21 12:22         ` Richard Sandiford

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