[LLVMdev] most optimised and lowest level IR before machine codegen?

[Yi Lin]

Hi,

I am interested to know how to get the most optimised IR (the compiler 
won't do any higher level opt but only translates it down to MC).

I tried to emit LLVM IR in clang by using '-S -O3 -emit-llvm'. Then I 
tried to use 'opt' to optimise it, but it seems to produce the same code.

Can I assume that LLVM will not do any code transformation on this level 
of IR but directly translate this IR into MC?
Is there any internal lower-level IR that LLVM uses during the machine 
code generation?

Thank you very much.

Regards,
Yi