We just added the __cpu_features__ structure. I am not quite sure what it provides, but there are up to three things that are interesting.

The CPU features:

1. supported by the system
2. NumPy is compiled with (targeted)
3. the union of both (i.e. the ones that are actually in use for the running instance)

I am wondering if we should add that information @seiko2plus, @mattip? That could be either by providing an additional struct, or assuming that we currently have the "supported by the system" definition, we change True to a string "enabled" and "supported" (the truthiness of which actually evaluates to the identical thing). Information "2." would not be available, but I am not sure it is super relevant.

EDIT: Sorry, if we are using definition "3.", I think that is probably all good, but I thought we may be using definition "1." in which case I wonder it is what we actually want to know in most cases.