[PATCH] D77576: [globalisel] Add lost debug locations verifier

Fri Apr 10 17:47:50 PDT 2020

dsanders added inline comments.

================
Comment at: llvm/lib/CodeGen/GlobalISel/LostDebugLocObserver.cpp:83
+  if (MI.getOpcode() != TargetOpcode::G_CONSTANT &&
+      MI.getOpcode() != TargetOpcode::G_FCONSTANT) {
+    PotentialMIsForDebugLocs.erase(&MI);
----------------
vsk wrote:
> Please have this return early, ideally like 'if (MI.isConstant()) return;'
> 
> I don't mean to suggest that you make tangential changes, it's just that it seems like there's a need for such a predicate (e.g. https://llvm.org/doxygen/AMDGPUInstructionSelector_8cpp_source.html#l01470 defines isConstant for MIs but leaves out G_FCONSTANT).
I looked at this again and found I'd missed G_IMPLICIT_DEF and G_GLOBAL_VALUE which also have their debug locations removed by the IRTranslator to avoid 'jumpy' behaviour in the debugger. I've added a predicate so we don't have two copies of the code in this file but it's not really meaningful for other code.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77576/new/

https://reviews.llvm.org/D77576