[llvm-commits] [llvm] r84134 - in /llvm/trunk/lib/CodeGen/AsmPrinter: DwarfDebug.cpp DwarfDebug.h

[Chris Lattner]

On Jan 15, 2010, at 2:06 PM, Devang Patel wrote:

>
> On Jan 15, 2010, at 1:52 PM, Chris Lattner wrote:
>
>> ping?
>
> Right now, FE relies on MDNode::replaceAllUsesWith. We need to come  
> up of another way to handle recursive constructs in FE.

This code is in the code generator's asmwriter, not in the frontend.   
The frontend should be done by the time these are created.

> Plus,
> MDNode's replaceOperand may also trigger MDNode::replaceAllUsesWith.  
> So, Between beginFunction() and endFunction(), if metadata changes  
> (Dale is introducing new machine instruction with a metadata  
> operand, which may change during codegen pipeline) then we need  
> WeakVH to track MDNode.
>
> I have not had a chance to measure DbgScope's impact on performance.  
> I'll do the measurement then update it, if required, appropriately.  
> Meanwhile, I am adding FIXME now.

The code generator should only be run when the metadata is all done, I  
don't see how it can change here.

-Chris