[LLVMdev] Question on sret

[Eli Friedman]

On Wed, Jul 14, 2010 at 8:49 AM, John Criswell <criswell at uiuc.edu> wrote:
> Dear All,
>
> What is the purpose of the sret function parameter attribute?  Does it
> affect the calling convention used during code generation, is it a hint
> to optimizations, or is it used for something else?

Both of the above; see LangRef.

> I'm currently working on automatic pool allocation; this transform
> clones a function and adds extra parameters to the beginning of the
> function's parameter list.  This means that I have to remove the sret
> attribute from the original first parameter.  Is removing sret safe?

Removing sret changes the calling convention, but otherwise it's safe.

-Eli