mesa: Replace a priori knowledge of gcc builtins with configure tests.
Presumbly this will let clang and other compilers use the built-ins as
well.
Notice two changes specifically:
- in _mesa_next_pow_two_64(), always use __builtin_clzll and add a
static assertion that this is safe.
- in macros.h, remove the clang-specific definition since it should
be able to detect __builtin_unreachable in configure.
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com> [C bits]
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
6 files changed