[PATCH] D45637: [DebugInfo] Ignore DBG_VALUE instructions in PostRA Machine Sink

[Bjorn Pettersson via Phabricator via llvm-commits]

bjope added a comment.

This comment in the description does not make sense to me:

> The original logic intentionally ignores all call instructions. Since debug intrinsics
>  are represented as calls, the pass was skipping that block and not
>  performing the sink.

The debug intrinsic is no longer a call after being lowered to DBG_VALUE. So it must have been something else that caused the debug invariant behavior, right?
I guess it was the call to  `TII->trackRegDefsUses` (on trunk it is `LiveRegUnits::accumulateUsedDefed`), done for non COPY instructions, that would track register uses in debug instructions unless we avoid that somehow.

Could you update the description to make it less confusing?



================
Comment at: lib/CodeGen/MachineSink.cpp:1131
     ++I;
+    if (MI->isDebugValue())
+      continue;
----------------
Nowadays we have isDebugInstr() to cover all kinds of debug instructions. I suggest using that instead here, to make the check more general.


https://reviews.llvm.org/D45637