LP64 vs LLP64

https://en.wikipedia.org/wiki/64-bit_computing

64-bit data models
Data model short (integer) int long (integer) long long pointers,
size_t
Sample operating systems
LLP64,
IL32P64
16 32 32 64 64 Microsoft Windows (x86-64 and IA-64) using Visual C++; and MinGW
LP64,
I32LP64
16 32 64 64 64 Most Unix and Unix-like systems, e.g., Solaris, Linux, BSD, macOS. Windows when using Cygwin; z/OS
ILP64 16 64 64 64 64 HAL Computer Systems port of Solaris to the SPARC64
SILP64 64 64 64 64 64 Classic UNICOS[41] (versus UNICOS/mp, etc.)