[PATCH] D30438: SplitKit: Correctly implement partial copies

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz added inline comments.


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Comment at: lib/CodeGen/SplitKit.cpp:551
+        LaneMask & ~(TRI.getSubRegIndexLaneMask(BestCover));
+    while (LanesLeft.any()) {
+      unsigned BestIdx = 0;
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Is there any guarantee that this loop will actually terminate?  In other words, do we know that the set PossibleIndexes covers the lanes completely?


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Comment at: lib/CodeGen/SplitKit.cpp:572
+
+      if (BestIdx == 0)
+        report_fatal_error("Impossible to implement partial COPY");
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Would it make sense to add `|| BestCover <= 0`?


Repository:
  rL LLVM

https://reviews.llvm.org/D30438