cxx-mem-model merge [6 of 9] - libstdc++-v3

[Richard Henderson]

On 11/07/2011 06:44 AM, Andrew MacLeod wrote:
> rth: __sync_lock_test_and_set_1  could be provided by libgcc if the
> OS has hooks in it to provide functionality...  How can we tell when
> compiling a C++ program whether that is going to be an unresolved
> external or whether libgcc is going to provide it? I know you have a
> pending patch for libgcc support fo the __atomics, but Im unsure how
> we check this from the compiler

In the pending patch, several of the direct_optabs get transformed
to normal optabs, and have the opportunity to have their libcall
fields filled in.

At which point one checks both optab_handler and optab_libcall for
the availability of the feature.


r~