[llvm-branch-commits] [GlobalISel] Combiner: Observer-based DCE and retrying of combines (PR #102163)

[Tobias Stadler via llvm-branch-commits]

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@@ -45,61 +45,190 @@ cl::OptionCategory GICombinerOptionCategory(
 );
 } // end namespace llvm
 
-/// This class acts as the glue the joins the CombinerHelper to the overall
+/// This class acts as the glue that joins the CombinerHelper to the overall
 /// Combine algorithm. The CombinerHelper is intended to report the
 /// modifications it makes to the MIR to the GISelChangeObserver and the
-/// observer subclass will act on these events. In this case, instruction
-/// erasure will cancel any future visits to the erased instruction and
-/// instruction creation will schedule that instruction for a future visit.
-/// Other Combiner implementations may require more complex behaviour from
-/// their GISelChangeObserver subclass.
+/// observer subclass will act on these events.
 class Combiner::WorkListMaintainer : public GISelChangeObserver {
-  using WorkListTy = GISelWorkList<512>;
-  WorkListTy &WorkList;
+protected:
+#ifndef NDEBUG
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tobias-stadler wrote:

Good point, but I don't think it's needed in this case, because you can't get the complete type of WorkListMaintainer outside of Combiner.cpp. Combiner.h only contains the declaration. Thoughts?

https://github.com/llvm/llvm-project/pull/102163