[LLVMdev] Unimplemented documentation

[Dan Gohman]

On Jan 24, 2009, at 4:34 AM, Lennart Augustsson  
<lennart at augustsson.net> wrote:

> Hi,
>
> Is there some documentation about what has not been implemented yet?

I've started adding notes to
docs/LangRef.html

Historically this document has been used to describe just the LLVM IR,  
and not what specific consumers of it do or don't support, but codegen  
is a very important consumer, so I've started adding notes about its  
limitations.

>
> I'm trying to use vectors and I just run into one thing after another
> that seem to be missing.
> (I.e., fcmp on vectors doesn't work; trying to do the same thing with
> expanded instructions doesn't work; select on a vector doesn't work)

A common thread here is that the code generator doesn't support  
vectors of booleans very well yet. Comparisons and selects are very  
useful (and are also the first step towards more advanced conditional  
vector support), so we'd really like to see this fixed, though it will  
depend on  someone stepping forward to do the work.

What do you mean by "expanded instructions"?

Dan