Constant FEATURE_FLAGS_C 

pub const FEATURE_FLAGS_C: CpuidValue<0x1, 0x0, ECX, FeatureFlagsC>;

Leaf/Function 0x1, ECX

[intel/vol2]: Table 3-10. Feature Information Returned in the ECX Register. [amd/vol3]: E.3.2, CPUID Fn0000_0001_ECX Feature Identifiers.