[exDM69]

I'm guessing that it's only conventions to work around the hardware specific parts of LLVM IR. Stuff like pointer and integer size, etc.

If you want to look at something similar, OpenCL has an LLVM IR -based standardized binary IR.

[DannyBee]

Actually, this is very wrong :)

SIL has a very large number of differences from LLVM IR. It's essentially built as an IR that the can do static analysis and high level optimization on.

This means it has a number of higher level constructs that LLVM doesn't, in order to be able to achieve the semantics they want for static analysis, and in order to be able to do things like optimize dispatch.