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

[Zack Weinberg]

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).

Also please add commentary to std_expand_builtin_va_arg explaining
what this code is doing.

zw