va-arg-25.c still fails on i686-linux

[Geoffrey Keating]

On 12/01/2004, at 4:37 PM, Jan Hubicka wrote:

>> Jan Hubicka <hubicka@ucw.cz> writes:
>>
>>>>
>>>> On 09/01/2004, at 11:06 PM, Zack Weinberg wrote:
>>>>
>>>>>
>>>>> I am still seeing va-arg-25.c fail at all optimization levels on
>>>>> i686-linux.  It has done so, as far as I can tell, ever since it
>>>>> was introduced.  Could you please either fix it or XFAIL it?
>>>>>
>>>> I think it would be better if an x86 port maintainer looked at this
>>>> failure.  The testcase does not fail on powerpc-Darwin.
>>>
>>> It don't even need x86 port maintainer :)
>>> The problem is wrong aligning of va_arg inside builtins.c when 
>>> argument
>>> alignment exceeds PARM_BOUNDARY.
>>>
>>> Additionally I noticed some problems with SSE enabled (we mistakely 
>>> used
>>> SSE regiser for variadic call and output warning)
>>>
>>> Note that I am not quite sure about the PAD_VARARGS_DOWN check, it 
>>> just
>>> seems appropriate at that place.
>>>
>>> Bootstrapping/regtesting in progress, OK if it passes?
>>
>> The concept looks good but I am nervous about a change in
>> machine-independent code.  Can you arrange testing on a few more
>> architectures?  (especially ones with complicated rules about
>> arguments being passed in registers - ia64 comes to mind).
>
> Every architecture passing arguments in registers use it's own va_arg
> expander (see ia64_va_arg).  This code triggers only in quite specific
> case of architecture having no register passing convention but still
> requiring larger alignment than word for some operands.  I know only of
> i386 being such a crazy creature.

ppc does this, in fact that was the motivation for this testcase.