__gcc_cpu_feature

[Paolo Carlini]

Richard Guenther wrote:

>Just to put some more thoughts on the table, I'm about to propose adding
>a __gcc_cpu_feature symbol to $suitable_place, similar to what Intel is
>doing with its __intel_cpu_indicator which is used in their runtime libraries
>to select different code paths based on processor capabilities.  I'm not
>yet sure if and how to best expose this to the user, but internally this could
>be mapped 1:1 to what we have in the TARGET_* flags.
>  
>
Richard, I think that irrespective of the current needs of v3, this
preprocessor builtin can be very useful for people wanting to flexibly
configure their projects to exploit the builtins when available. I would
like to see you proposing a finished patch.

Are there objections?

Paolo.