From: dfawcus+lists-tuhs@employees.org (Derek Fawcus)
Subject: [TUHS] C declarations.
Date: Sun, 14 May 2017 14:14:44 +0100 [thread overview]
Message-ID: <20170514131444.GB81508@cowbell.employees.org> (raw)
In-Reply-To: <1494702324.1901172.975588504.1BA76452@webmail.messagingengine.com>
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On Sat, May 13, 2017 at 03:05:24PM -0400, Random832 wrote:
> On Sat, May 13, 2017, at 08:20, Michael Kjörling wrote:
> > Correct me if I am wrong, but _pass by value_ as opposed to _pass by
> > reference_ requires making a copy, no? That's the whole point, to
> > allow the callee to poke at the value it is given at will.
>
> If that were the issue, the callee could simply automatically make the
> copy if-and-only-if it needs it.
I recall reading a proposed ABI for C on MIPS which would have done
something similar for passing structs by value, namely pass a pointer
but allocate local storage space in the callee. If the callee ever
assigned to the passed struct, it was to copy the actual values,
then update its pointer. I don't think that ABI was ever implemented.
DF
next prev parent reply other threads:[~2017-05-14 13:14 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-11 21:49 Ron Natalie
2017-05-11 22:01 ` Arthur Krewat
2017-05-11 23:44 ` Dave Horsfall
2017-05-11 22:03 ` David Arnold
2017-05-11 22:32 ` Larry McVoy
2017-05-11 22:41 ` Ron Natalie
2017-05-13 1:24 ` Larry McVoy
2017-05-13 2:45 ` Ron Natalie
2017-05-13 12:20 ` Michael Kjörling
2017-05-13 12:35 ` Tim Bradshaw
2017-05-13 12:42 ` Michael Kjörling
2017-05-13 15:36 ` Stephen Kitt
2017-05-14 1:59 ` Lawrence Stewart
2017-05-14 2:23 ` Dave Horsfall
2017-05-14 4:24 ` Bakul Shah
2017-05-14 6:12 ` Steve Johnson
2017-05-14 6:48 ` Bakul Shah
2017-05-14 23:06 ` Ron Natalie
2017-05-14 23:34 ` Arthur Krewat
2017-05-15 0:14 ` Dan Cross
2017-05-15 0:23 ` Ron Natalie
2017-05-15 3:43 ` Random832
2017-05-15 0:40 ` Larry McVoy
2017-05-15 2:00 ` Nevin Liber
2017-05-15 10:21 ` Tony Finch
2017-05-15 4:35 ` Dave Horsfall
2017-05-15 4:54 ` Bakul Shah
2017-05-15 5:01 ` Dave Horsfall
2017-05-15 12:58 ` Michael Kjörling
2017-05-15 16:58 ` Dave Horsfall
2017-05-15 19:00 ` [TUHS] cdecl (Re: " Bakul Shah
2017-05-15 22:52 ` Dave Horsfall
2017-05-13 13:46 ` [TUHS] " Hellwig Geisse
2017-05-13 19:08 ` Random832
2017-05-13 23:21 ` Dave Horsfall
2017-05-14 14:48 ` Nemo
2017-05-13 19:05 ` Random832
2017-05-14 13:14 ` Derek Fawcus [this message]
2017-05-12 0:15 ` Bakul Shah
2017-05-12 2:41 ` Theo Pavlidis
2017-05-12 14:04 Richard Tobin
2017-05-13 23:11 Richard Tobin
2017-05-15 6:46 ` Tim Bradshaw
2017-05-14 14:11 Doug McIlroy
2017-05-14 14:58 ` Steve Nickolas
2017-05-15 18:47 Steve Johnson
2017-05-15 19:54 ` Bakul Shah
2017-05-16 7:25 ` George Ross
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