[LLVMdev] Metadata

[Dan Gohman]

On Feb 11, 2010, at 3:41 PM, Devang Patel wrote:

> Dan,
> 
>> Sharing only happens when two instructions have the "same" memory
>> reference info. You just need to make sure that the non-temporal
>> flag is significant. It's not fundamentally different from the
>> volatile flag in this respect.
> 
> Metadata is used to monitor values from the sideline. It should not
> influence optimization or code gen in general other then the intended
> recipient of the metadata info. So your suggestion is not a good idea
> for all kind of metadata in general. Just a note.

I was talking about MachineMemOperands in the above, not metadata.

But that does suggest a consideration: if you're using metadata at
the LLVM IR level, it may make sense to use metadata at the codegen
level too, to avoid this confusion.

Dan