[LLVMdev] How to call a pointer that points to a C function

C K Tan cktanx at gmail.com
Mon Oct 27 00:46:58 PDT 2014

I have a pointer to a function that I need to invoke without going
through llvm::Module::getOrInsertFunction. This example does not work:

static int add(int x, int y);
llvm::Value *one, *two;

llvm::Constant* addfn
   = llvm::ConstantInt::get(JB->getIntPtrTy(DataLayout), (intptr_t)add);
llvm::Type* args[] = { Int32Ty, Int32Ty };
llvm::FunctionType* ftype = llvm::FunctionType::get(Int32Ty, args);
addfn = llvm::ConstantExpr::getPointerCast(addfn, ftype);
CreateCall(addfn, one, two);


Is there a way? Or must I call getOrInsertFunction?

Before anyone asks why I am doing this, it is because I have maybe 200
functions with the same signature that I would like JIT a call to. I
would like to avoid calling getOrInsertFunction 200 times. I know
exactly the address of the functions.


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