[LLVMdev] casting Constant * to value *?

[John Criswell]

On 3/17/15 8:40 PM, Alexander Poddey wrote:
> Hi all,
>
> extracting datafields of globals, the API code ends up in a Constant *
>
>
> Constant* const_ptr_103 = ConstantExpr::getGetElementPtr(gvar_struct_foo,
> const_ptr_103_indices);
>
> it can be used to initialize e.g. a new instruction like:
>
> StoreInst* void_119 = new StoreInst(const_float_102, const_ptr_103, false,
> label_entry_113);
>
>
> But how about replacing the operand of an already existing instruction using
> a Constant *?
>
> Instruction->setOperand(1,__needs_a_value*_here__);

If you look at the inheritance tree, you'll see that an llvm::Constant 
is a subclass of llvm::Value.  Therefore, you can use an llvm::Constant 
anywhere in which an llvm::Value is needed.

To look at the inheritance tree, look at the LLVM doxygen documentation.

Regards,

John Criswell
>
>
> Thx
> Alex
>
>
>
>
>   
>
>
>
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-- 
John Criswell
Assistant Professor
Department of Computer Science, University of Rochester
http://www.cs.rochester.edu/u/criswell