[LLVMdev] RFC: Separate machine IR from lib/CodeGen into lib/MIR

[Duncan P. N. Exon Smith]

> On 2015-May-26, at 09:46, Alex L <arphaman at gmail.com> wrote:
> 
> Hi all,
> 
> The CodeGen library is a big bag of interdependent bits. This caused
> a circular dependency in the MIR serialization commit (r237954), which got
> reverted in r238007.
> 
> I propose separating the machine IR out of CodeGen and into its own
> MIR library, living at lib/MIR. This touches every target but it's mostly a
> mechanical change that renames the header files, although a couple of pre-rename
> commits are needed to decouple several things in CodeGen. I've attached a proof
> of concept patch that renames the files and applies cleanly to r238038.
> 
> The MIR serialization code will go under the new MIR library and not under
> CodeGen which will break the dependency. The CodeGen library will link MIR
> automatically so the build files for tools that link with CodeGen won't have to
> be changed.
> 
> Thanks for reading,
> Alex
> 

FWIW, I'm in favour of this.  I'd be interested to hear if there's
a reason *not* to do this.

Here's some more context:

  http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150518/278031.html