Re: Darwin bootstrap failure following wide int merge

[Richard Sandiford <rsandifo at linux dot vnet dot ibm dot com>]

Richard Biener <richard.guenther@gmail.com> writes:
> On Wed, May 28, 2014 at 11:40 AM, Richard Biener
> <richard.guenther@gmail.com> wrote:
>> On Wed, May 28, 2014 at 10:24 AM, Richard Sandiford
>> <rdsandiford@googlemail.com> wrote:
>>> Richard Biener <richard.guenther@gmail.com> writes:
>>>> On Wed, May 28, 2014 at 8:50 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>>>>> On Mon, May 26, 2014 at 08:36:31AM -0700, Mike Stump wrote:
>>>>>> On May 26, 2014, at 2:22 AM, FX <fxcoudert@gmail.com> wrote:
>>>>>> >> This causes GCC bootstrap to fail on Darwin systems (whose system
>>>>>> > compiler is clang-based). Since PR 61146 was resolved as INVALID
>>>>>> > (but Iâm not sure itâs the right call, see below), Iâve filed a
>>>>>> > separate report for the bootstrap issue
>>>>>> > (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61315).
>>>>>> >
>>>>>> > Since my PR has been closed twice by Andrew Pinski (âitâs clangâs
>>>>>> > fault, bouh ouhâ), Iâd ask the maintainers to step in. Can we
>>>>>> > please provide a GCC that works for the default darwin setup? Or at
>>>>>> > least drop darwin as secondary target and document the failure?
>>>>>>
>>>>>> The best coarse of action, post a patch, have it reviewed and put in.
>>>>>> Current action, a patch has been posted, the review is outstanding, Iâd
>>>>>> like to see it put in; though, I am curious why the casts were there in
>>>>>> the first place.
>>>>>
>>>>> Note, haven't added them there, but from what I can test, the casts there
>>>>> can serve as a compile time check that the right type is used, e.g.
>>>>> unsigned long i;
>>>>>
>>>>> void
>>>>> foo (void)
>>>>> {
>>>>>   asm volatile ("# %0 %1" : "=r" ((unsigned long long) i) : "0"
>>>>> ((unsigned long long) 0));
>>>>> }
>>>>
>>>> Ah, interesting.  A not-so-hineous extension then.
>>>
>>> In that case, how about just protecting the include with:
>>>
>>> #if GCC_VERSION >= 4300 && (W_TYPE_SIZE == 32 || defined (__SIZEOF_INT128__))
>>>
>>> rather than:
>>>
>>> #if GCC_VERSION >= 3000 && (W_TYPE_SIZE == 32 || defined (__SIZEOF_INT128__))
>>>
>>> so that clang will fail the version check?  At the end of the day we
>>> only really care what happens during stage 2 and 3.  Cross-compilers
>>> built with recentish gccs will still benefit.
>>
>> Works for me (thus, pre-approved with a comment explaining the version
>> choice).
>
> Btw, testing coverage would ask for && defined (__OPTIMIZE__), too, disabling
> that path in stage1 unconditionally even for new GCC.

Ah, but surely the day is near when we use -O or -Og for stage1?
I've been using -O for a good few years now and it definitely makes
things faster (and without affecting debugging too much -- in the
rare cases where it does affect debugging, a recompile with -g
is very quick).

ATM we get the testing coverage for i686 and ppc32 hosts.  So TBH I'd
prefer to keep it simple and just bump the version number.

Thanks,
Richard