bli_arch_query_id() is used to select kernels in optimized BLAS APIs. Previous
implementation incurred the overhead of multiple function calls. This has
been reduced by:
- Changing the function to be defined in a header file so it can be inlined.
- Avoiding call to bli_arch_check_id_once that was a wrapper for a call to
bli_pthread_once. Instead bli_pthread_once is called directly.
- For builds with a single BLIS sub-configuration, correct arch_id is taken
directly from a header file in the corresponding config subdirectory,
avoiding the bli_pthread_once call and making the value explicit at
compile time, which may enable additional optimizations.
To enable these changes, the variables arch_id and model_id defined in
frame/base/bli_arch.c are no longer static, as they must be accessed in multiple
files (i.e. they are now global variables). Rename to g_arch_id and g_model_id
to distinguish from any locally defined arch_id or model_id variables.
