Re: [v3] updated atomic configury

[Andrew MacLeod <amacleod at redhat dot com>]

On 11/21/2011 11:02 PM, Andrew MacLeod wrote:
> Anyway, it looks like __atomic_always_lock_free doesn't fold early 
> enough to be usable by the preprocessor like that even with my earlier 
> version. ugg.  I think I can get something defined in cpp-builtins 
> that we can use.   We're going to need it for C1x next release 
> anyway.  Should be ready to try tomorrow sometime.
Ok, try this.  I've changed CPP to define a set of macros
__GCC_ATOMIC_{TYPE}_IS_LOCK_FREE
which we can use directly in the c++ header.  We're going to need 
something like this for C1x next release when stdatomic.h defines the 
same macros.

C currently doesn't have a char16_t and char32_t, so they aren't defined 
there. I defined them in the C++ header with the appropriate 
HAVE_COMPARE_AND_SWAP.

this should make things work the way you were looking for, ie

#if (ATOMIC_INT_LOCK_FREE>  1)
// yes, cool, yeah!
#endif

should work just fine.

Give it a shot and see if you get what you are looking for.  Ive 
bootstrapped this on x86_64-unknown-linux-gnu, and didn't see any 
regressions in libstdc++-v3...   Im running a full bootstrap and 
testsuite run overnight

Andrew

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