Patch ping (was Re: [PATCH] libstdc++: Clear padding bits in atomic compare_exchange)

[Rainer Orth]

Hi Jonathan,

> Here's a complete patch that combines the various incremental patches
> that have been going around. I'm testing this now.
>
> Please take a look.

unfortunately, this patch broke macOS bootstrap (seen on
x86_64-apple-darwin11.4.2):

In file included from /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/shared_ptr_atomic.h:33,
                 from /var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/memory:78,
                 from /vol/gcc/src/hg/master/darwin/libstdc++-v3/include/precompiled/stdc++.h:82:
/var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/atomic_base.h: In function 'bool std::__atomic_impl::__compare_exchange(_Tp&, _Val<_Tp>&, _Val<_Tp>&, bool, std::memory_order, std::memory_order)':
/var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/atomic_base.h:1008:49: error: expected primary-expression before ',' token
 1008 |                                           __weak, int(__s), int(__f)))
      |                                                 ^
/var/gcc/regression/master/10.7-gcc/build/x86_64-apple-darwin11.4.2/libstdc++-v3/include/bits/atomic_base.h:1017:50: error: expected primary-expression before ',' token
 1017 |                                            __weak, int(__s), int(__f));
      |                                                  ^

Darwin gcc predefines __weak= in gcc/config/darwin-c.cc (darwin_cpp_builtins).

	Rainer

-- 
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Rainer Orth, Center for Biotechnology, Bielefeld University