[Openmp-dev] clang: Emit Target Functions when #pragma omp declare target

Daniel Schürmann via Openmp-dev openmp-dev at lists.llvm.org
Fri Dec 1 07:18:21 PST 2017


I wanted to ask, if this behavior is on purpose or if I am missing 

To me it seems that using "#pragma omp declare target" has no effect on 
the code generation.
The specification states that variables and functions are mapped to the 
In my understanding, this means that device code should be emitted.

However, CGOpenMPRuntime::emitTargetGlobal() does only search for target 
#pragmas and doesn't check for OMPDeclareTargetDeclAttr. This check is 
done in ASTContext::DeclMustBeEmitted(), but it seems, this can never 
happen. The reason is that CodeGenModule::EmitGlobal() returns early 
after calling CGOpenMPRuntime::emitTargetGlobal(). I hope, this is 

It might be that this problem never showed up when the device is x86 as 
well. But I don't understand how Nvidia can compile e.g. lulesh like this...

My question is if the intended way would be to change emitTargetGlobal() 
to also emit functions/variables with OMPDeclareTargetDeclAttr.

Thanks in advance,

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