Constant ADDRESS_SIZE_INFO 

pub const ADDRESS_SIZE_INFO: CpuidValue<0x8000_0008, 0, EAX, AddressSizeInfo>;

Leaf/Function 0x8000_0008, EAX

[intel/vol2]: Table 3-8. Information Returned by CPUID Instruction. [amd/vol3]: E.4.7 Function 8000_0008h-Processor Capacity Parameters and Extended Feature Identification.