[llvm-dev] [GlobalISel][RFC] Thoughts on MachineModulePass

[Philip Reames via llvm-dev]

On 01/22/2016 03:16 PM, Quentin Colombet via llvm-dev wrote:
> Hi,
>
> In the initial thread of the proposal for GlobalISel, I have mentioned that it may be interesting to have a kind of MachineModulePass.
> Marcello mentioned this would be useful for their current pipeline.
>
> I am interested in knowing:
> 1. If anyone else is interested for such concept?
> 2. What kind of information should we make accessible in an hypothetical MachineModule? I.e., how do you plan to use the MachineModulePass so that we make the right design decisions for the MachineModule feeding those passes?
> 3. Who would be willing to work on that?
This could be interested from a GC perspective.  The current RS4GC pass 
which exists as an IR to IR transform would be (potentially) nice to 
push back into the backend.  It's inherently a module level pass, so 
having an MI layer equivalent could be useful.  Note that I'm not saying 
"required" or even "definitely useful"; I suspect we can find a 
practical engineering compromise today by splitting RS4GC into two or 
more pieces that run at different times.

Also, just an FYI, we already have Module level analysis passes over MI, 
but only the immutable variety.  One of those is used by the gc.root 
infrastructure.  See GCModuleInfo.
>
> Thanks,
> -Quentin
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev