[llvm-dev] Live DEBUG_VALUE analysis transfer

[Adrian Prantl via llvm-dev]

> On Aug 1, 2019, at 3:50 PM, Son Tuan VU via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> Hello,
> 
> Looking at the code of Live DEBUG_VALUE analysis which propagates debug information by inserting new DBG_VALUE instructions to the MIR.
> 
> Currently, this pass inserts new DBG_VALUE instructions for register copy, spill and restore instructions. However, extend instructions such as ARM's {S|U}XT{B|H} should also have new DBG_VALUE instructions inserted, since they do kill and define registers.
> 
> Is this just a TODO that needs to be implemented, or there is in fact a reason for this?
> 

Could you post a short example that illustrates the issue? LiveDebugValue's primary purpose is to propagate DBG_VALUEs across basic block boundaries. Based on your description I'm not sure whether this wouldn't be a better fit for a different phase.

-- adrian