[LLVMdev] Passing a pointer to a function

Scott Ricketts sricketts at maxentric.com
Thu May 21 08:17:46 PDT 2009

Eli: Thanks for the quick and helpful response.

> I would suggest bit-casting p to an i8*.

Yup, that did the trick:

visitLoadInst(LoadInst &I) {
  Value *P = I.getPointerOperand();

  const Type *PtrTy = PointerType::getUnqual(Type::Int8Ty);

  BasicBlock::iterator it(I);

  CastInst *CI =
    CastInst::Create(Instruction::BitCast, P, PtrTy, "", it);

  CallInst::Create(load_fcall, CI, "", it);

> I'm not sure why you're getting crashes with the last approach; it
> looks like it should work.

In that particular case, it encounters a pointer to an element of type
label and then segfaults on the call to isInteger(). I didn't look
into this bug because of the bitcast solution works for now.


More information about the llvm-dev mailing list