[LLVMdev] simulating c style unions in LLVM

Eli Friedman eli.friedman at gmail.com
Mon Jun 29 23:20:48 PDT 2009

On Mon, Jun 29, 2009 at 11:09 PM, Carter Cheng<carter_cheng at yahoo.com> wrote:
> I am trying to create a boxed tagged datatype for a language where it is necessary to resolve the type at runtime. If I were writing an interpreter in C- it would most likely look something like this-
> struct
> {
>    unsigned tag;
>    union { long Int; double Float; .... }
> }
> Is there a standard way for constructing a type like this in LLVM?

You have to write it using bitcasts.  Try looking at llvm-gcc or clang
output for a rough outline.


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