[PATCH] D78135: [MachineDebugify] Insert synthetic DBG_VALUE instructions

[Vedant Kumar via Phabricator via llvm-commits]

vsk created this revision.
vsk added reviewers: dsanders, aprantl.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

Teach MachineDebugify how to insert DBG_VALUE instructions.  This can
help find bugs causing CodeGen differences when debug info is present.
DBG_VALUE instructions are only emitted when -debugify-level is set to
locations+variables.

There is essentially no attempt made to match up DBG_VALUE register
operands with the local variables they ought to correspond to. I'm not
sure how to improve the situation. In some cases (MachineMemOperand?)
it's possible to find the IR instruction a MachineInstr corresponds to,
but in general this seems to call for "undoing" the work done by ISel.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D78135

Files:
  llvm/lib/CodeGen/MachineDebugify.cpp
  llvm/test/CodeGen/Generic/MIRDebugify/locations.mir

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D78135.257411.patch
Type: text/x-patch
Size: 5494 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200414/881a74f4/attachment.bin>