[PATCH] D139590: [RegAllocFast] Handle new debug values for spills

Wed Dec 7 16:44:44 PST 2022

MatzeB added a subscriber: StephenTozer.
MatzeB added a comment.

- I'm somewhat confused that this problem isn't breaking things all over the place and wasn't noticed until now... There must be something unusual here that I don't understand yet...
- This change feels wrong to me: `handleDebugValue()` is making use of the `LiveRegMap` infrastructure (`findLiveVirtReg`) which describes the state at the point of the program where we are currently allocating; However `NewDV` was created a different position (wherever the previous debug instruction was located that is rewritten).
- I have a feeling that this may be related to DBG_VALUE_LIST / D92578 <https://reviews.llvm.org/D92578> / CC @StephenTozer as we now suddenly have multiple operands and the problematic vreg operand is an unrelated operand to the spill instruction and is just copied around by `buildDbgValueForSpill`...

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139590/new/

https://reviews.llvm.org/D139590