llvm dev - Oct 2012 - [LLVMdev] 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

On 10/9/12 1:19 PM, apala guha wrote:
> 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.
> -Apala
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

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

On 10/09/2012 01:24 PM, John Criswell wrote:
> On 10/9/12 1:19 PM, apala guha wrote:
>> 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.
>> -Apala
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>