[llvm-dev] LLVM and Pthreads

[Doerfert, Johannes via llvm-dev]

Hi Iulia,

The declaration Rob has shared was never part of mainline LLVM (afaik).
The implementation Rob provided should however still work.
Have you tried it?

There is no need to add/change anything in the machine representation.

Cheers,
  Johannes



On 04/22, Iulia Stirb via llvm-dev wrote:
> Hello all,
> I am returning to this subject after a while and I was looking for CBuilder::CreatePThreadCreateCall function below. I cannot find it anywere and I guess it has been rename or changed into a more generic one. I would want to insert a phtread call into the input source code. Which builder class to use for that instead of CBuilder class? If I insert the call into IR representation, do I need to insert the call also into machine representation?
> Kind regards,
> ----------------------------------------------------------Iulia ȘTIRBPhD Student in Computer ScienceAssociate Teaching AssistantDepartment of Computers and Software EngineeringPolitehnica University of Timișoara2 Piața Victoriei, Timișoara, Romania, 300006 Tel.: +(40) 76 560 3230E-mail: iulia.stirb at gmail.com, iulia_s24 at yahoo.comSkype: iulia.stirb----------------------------------------------------------
> 
> 
> 
> 
>  
> 
>     On Saturday, May 6, 2017, 5:58:03 PM GMT+3, Rob Cameron <cameron at cs.sfu.ca> wrote:  
>  
>  Hi, Iulia.
> 
> You can create calls to pthread routines.  For example, this is a declaration
> in one of our header files.
> 
>   //  Create a call to:  int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
>   //                    void *(*start_routine)(void*), void *arg);
>   llvm::Value * CreatePThreadCreateCall(llvm::Value * thread, llvm::Value * attr, 
>                                         llvm::Function * start_routine, llvm::Value * arg);
> 
> Here is our implementation (mMod is the Module * containing the code we are building).
> 
> Value * CBuilder::CreatePThreadCreateCall(Value * thread, Value * attr, Function * start_routine, Value * arg) {
>     Type * const voidPtrTy = getVoidPtrTy();
>     Function * pthreadCreateFunc = mMod->getFunction("pthread_create");
>     if (pthreadCreateFunc == nullptr) {
>         Type * pthreadTy = getSizeTy();
>         FunctionType * funVoidPtrVoidTy = FunctionType::get(getVoidTy(), {getVoidPtrTy()}, false);
>         FunctionType * fty = FunctionType::get(getInt32Ty(), {pthreadTy->getPointerTo(), voidPtrTy, funVoidPtrVoidTy->getPointerTo(), voidPtrTy}, false);
>         pthreadCreateFunc = Function::Create(fty, Function::ExternalLinkage, "pthread_create", mMod);
>         pthreadCreateFunc->setCallingConv(CallingConv::C);
>     }
>     return CreateCall(pthreadCreateFunc, {thread, attr, start_routine, CreatePointerCast(arg, voidPtrTy)});
> }
> 
> The actual routine called is determined at link time.  In our case, 
> we rely on the ExecutionEngine to dynamically link to the pthread routines 
> available on our target platform.  This approach works well for us on both
> Linux and Mac OS.  I don't know what happens with Windows OS.
> 
> 
> 
> ----- On May 6, 2017, at 4:16 AM, Iulia Stirb via llvm-dev llvm-dev at lists.llvm.org wrote:
> 
> > Hello,
> > I know clang supports -pthread option (here). Does this mean I can call pthread
> > routines inside llvm code and which pthread library is used, the one for Linux
> > OS or the one for Windows?
> > Thank you.Iulia
> > 
> > 
> > _______________________________________________
> > LLVM Developers mailing list
> > llvm-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>   

> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev


-- 

Johannes Doerfert
Researcher

Argonne National Laboratory
Lemont, IL 60439, USA

jdoerfert at anl.gov
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 228 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190422/abde8ef1/attachment.sig>