[PATCH] D83047: [LiveDebugValues] 2/4 Add instruction-referencing LiveDebugValues implementation

[Djordje Todorovic via Phabricator via llvm-commits]

djtodoro added inline comments.


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Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp:132
+///   Overlapping fragments
+///   Entry values
+///   Add back DEBUG statements for debugging this
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>From the RFC [0]:

>The new implementation has enough information to solve this, as it tracks all
>values in all machine locations. Unfortunately it doesn't make much difference
>to the location statistics for clang RelWithDebInfo builds. An additional
>benefit is that we would be better placed to produce saner locations lists [4].

Have you disabled the Debug Entry Values feature (in the original LideDebugValues) when comparing new and old implementations?
It adds a lot of extra inputs with location lists, so it may be interesting to see the comparison without it.

[0] http://lists.llvm.org/pipermail/llvm-dev/2020-June/142368.html


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Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp:1648
+  // Copy MTracker info, including subregs if available.
+  InstrRefBasedLDV::performCopy(SrcReg, DestReg);
+
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This will help us to get rid of [0]?

[0] https://github.com/llvm/llvm-project/blob/f24ac13aaae63d92317dac839ce57857a7b444dc/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp#L587


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