Most built-in types have implementation-defined sizes. The following table lists the amount of storage required for built-in types in Microsoft C++. In particular, long is 4 bytes even on 64-bit operating systems.
Type
Size
bool, char, char8_t, unsigned char, signed char, __int8
This returns the processor’s serial number. The processor serial number was introduced on Intel Pentium III, but due to privacy concerns, this feature is no longer implemented on later models (PSN feature bit is always cleared). Transmeta’s Efficeon and Crusoe processors also provide this feature. AMD CPUs however, do not implement this feature in any CPU models.
For Intel Pentium III CPUs, the serial number is returned in EDX:ECX registers. For Transmeta Efficeon CPUs, it is returned in EBX:EAX registers. And for Transmeta Crusoe CPUs, it is returned in EBX register only.
Note that the processor serial number feature must be enabled in the BIOS setting in order to function.
Processor information that describes the processor features. For an x86 class CPU, the field format depends on the processor support of the CPUID instruction. If the instruction is supported, the property contains 2 (two) DWORD formatted values. The first is an offset of 08h-0Bh, which is the EAX value that a CPUID instruction returns with input EAX set to 1. The second is an offset of 0Ch-0Fh, which is the EDX value that the instruction returns. Only the first two bytes of the property are significant and contain the contents of the DX register at CPU reset—all others are set to 0 (zero), and the contents are in DWORD format.”