llvm dev - Nov 2009 - [LLVMdev] embedded metadata

I have a quick question about embedded metadata. I've lost track of 
exactly what we want to support.

What about making MDNodes that refer to Instructions? Is that desired 
any more, or is that obsolete? I had a patch to do this locally and I 
either want to fix it up and commit it or discard it.

The relevant section of my locally modified 
test/Feature/embeddedmetadata.ll reads:

define void @foo() {
   ;; Intrinsic using MDNode and MDString
   %x = call i8 @llvm.something(metadata !21, i32 42, metadata !"bar")
   %y = call i8 @llvm.something(
       metadata !{i8 %x, i8 %y, i32 %z, metadata* @llvm.foo, null,
       i32* null, metadata undef, metadata !{i8 %y, metadata !"foo"}, 
metadata !"foo"})
   %z = add i32 1, 1
   ret void
}

where %y is a new instruction demonstrating the MDNode's ability to 
refer to other instructions.

Nick

On Sun, Nov 22, 2009 at 1:58 PM, Nick Lewycky <nicholas at mxc.ca>
wrote:
> I have a quick question about embedded metadata. I've lost track of
> exactly what we want to support.
>
> What about making MDNodes that refer to Instructions? Is that desired
yes.
> any more, or is that obsolete? I had a patch to do this locally and I
> either want to fix it up and commit it or discard it.
MDNode now holds values so it should work, but have not tried it yet.
If you run into to issues please let us know.

LLParser requires one change (that is -- accept inline metadata
content) and Victor is working on it so that
  call @llvm.dbg.declare(metadata !{i32* %X }, metadata !4)

works.

-
Devang