[LLVMdev] Incrementing a pointer to array element?

[Eli Friedman]

On Wed, Oct 17, 2012 at 5:19 PM, Paul J. Lucas <paul at lucasmail.org> wrote:
> Using the LLVM C++ API, if I want to create an array via an Alloca instruction like:
>
>         Value *a = ir_builder.CreateAlloca( my_type, my_size );
>
> and then I want to initialize each element of the array with values computed elsewhere like:
>
>         for ( vector<Value*>::const_iterator i = v.begin(); i != v.end(); ++i ) {
>           builder.CreateStore( *i, a );
>           // How do I increment 'a' to point to the next element?
>         }
>
> how do I increment 'a' to point to the next element (taking the size of my_type into account) so that each store instruction stores in successive elements?

    for ( vector<Value*>::const_iterator i = v.begin(); i != v.end(); ++i ) {
      builder.CreateStore( *i, a );
      a = builder.CreateGEP(a, Builder.getInt64(1));
    }

-Eli