[LLVMdev] The Trouble with Triples

[Renato Golin]

On 30 July 2015 at 14:52, Daniel Sanders <Daniel.Sanders at imgtec.com> wrote:
> We will need a string serialization of the TargetTuple so that we can store it in the IR and read it back.

Why does it have to be in the IR? If every tool that deals with IR has
the same options and they mean the same thing I don't see why we'd
need that.


> Whether this is in one piece (e.g. 'target tuple = "...") or multiple pieces (e.g. 'target arch = "..."', 'target endian = "..."') doesn't matter too much at first but I can see the benefits of the latter being the end point. If we do choose that multiple pieces then I'd like to pass through the former first to keep the early steps of the migration to a TargetTuple as simple and mechanical as possible.

Assuming we really need it, wouldn't it work if we put in metadata?
That way, it would bloat the IR of targets that really needed it and
not the ones that don't, at the same time as being non-critical to
parsing and validating the IR, so you could safely drop some
information without breaking the file.

This would allow more flexibility across targets, if they need
different types of storage, and would allow targets that do need the
info to complement the missing info with their own defaults. So we
could reuse old IR with new IR and still make it work.

cheers,
--renato