How to use MSVC intrinsics to get the equivalent of this GCC code?

Question

The following code calls the builtin functions for clz/ctz in GCC and, on other systems, has C versions. Obviously, the C versions are a bit suboptimal if the system has a

Answer 1

If MSVC has a compiler intrinsic for this, it'll be here:

Compiler Intrinsics on MSDN

Otherwise, you'll have to write it using __asm