Re: libffi trunk: new regressions on x86_64-linux-gnu, some test failures left on i686-linux-gnu

[Anthony Green <green at moxielogic dot com>]

That was the wrong report.. here's the right one:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85667

AG

On Sat, May 5, 2018 at 9:30 PM, Anthony Green <green@moxielogic.com> wrote:

> On Sat, May 5, 2018 at 10:36 AM, Kaz Kylheku (libffi) <
> 382-725-6798@kylheku.com> wrote:
>
>> On 2018-05-05 06:51, Anthony Green wrote:
>>
>>> These failures are showing up because we're testing the microsoft ABI
>>> now.
>>>
>>> This looks like a bug in GCC.  It's not returning small structures with
>>> floating point values in the right registers when following the Microsoft
>>> ABI.  I'm going to figure out how to 'xfail' those tests and open a bug
>>> against GCC.   Clang appears to get it right.
>>>
>>
>> When would this be an actual issue?
>>
>
> As far as I know this is the first time this bug has been reported.   I've
> filed it here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43869
>
> GCC is internally consistant, but can't generate code that will interface
> correctly to binaries built with clang or visual c.
>
> Since nobody has reported this problem before, I'm OK with having libffi
> follow the correct ABI as long as the GCC hackers agree to fix this in
> future versions of GCC.  Libffi won't work with GCC-compiled ms_abi
> functions returning short structs (8 bytes or less) containing floating
> point values (a pretty narrow use-case!).  This is why I'll just xfail
> the problematic test cases when we know we're using GCC.
>
> AG
>
>