function calls

Hi,

I am seeing some strange function calls in the LLVM IR, such as, 'call llvm.lifetime.start'. What are these functions and why are they appearing in the IR?

Thanks.
-Apala

Hi,

I am seeing some strange function calls in the LLVM IR, such as, 'call llvm.lifetime.start'. What are these functions and why are they appearing in the IR?

These are LLVM intrinsics that provide information to the optimization passes. See the Language reference manual (http://llvm.org/docs/LangRef.html) for a description of what these intrinsics do.

-- John T.

Thanks. Is there a way I can ignore the instructions calling LLVM intrinsics? Or, prevent them from getting into the IR representation?

Basically, I do not need optimization passes. I am only interested in analyzing the intermediate representation.

-Apala