Re: [PATCH] calls: Fix up TYPE_NO_NAMED_ARGS_STDARG_P handling [PR107453]

[Alexandre Oliva <oliva@gnu.org>]

On Feb 27, 2024, Richard Earnshaw <Richard.Earnshaw@arm.com> wrote:

> This one has been festering for a while; both Alexandre and Torbjorn
> have attempted to fix it recently, but I'm not sure either is really
> right...

*nod* xref https://gcc.gnu.org/pipermail/gcc-patches/2024-March/646926.html
The patch I proposed was indeed far too limited in scope.

> On Arm this is causing all anonymous arguments to be passed on the
> stack, which is incorrect per the ABI.  On a target that uses
> 'pretend_outgoing_vararg_named', why is it correct to set n_named_args
> to zero?  Is it enough to guard both the statements you've added with
> !targetm.calls.pretend_outgoing_args_named?

ISTM that the change you suggest over Jakub's patch would address the
inconsistency on ARM.

Matthew suggested a patch along these lines in the other thread, that I
xrefed above, that seems sound to me, but I also suspect it won't fix
the ppc64le issue.  My hunch is that we'll need a combination of both,
possibly with further tweaks to adjust for Jakub's just-added test.

-- 
Alexandre Oliva, happy hacker                    https://FSFLA.org/blogs/lxo/
   Free Software Activist                           GNU Toolchain Engineer
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