[PATCH] D55287: VirtRegMap: Support partially allocated virtual registers

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet added a comment.

> The LiveIntervals for the relevant regunits needs to be removed.

Could you elaborate on why we need to remove these?



================
Comment at: lib/CodeGen/VirtRegMap.cpp:624
+      }
+    }
+  }
----------------
Although that's unlikely to happen, we could imagine that another physical reg that share regunits with the one we are clearing is still relevant for subsequence allocation.

Put differently, why is this code valid?

In theory we may clear RegA's regunits, while they overlap with RegB's regunits and RegB's live interval needs to be valid.


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  https://reviews.llvm.org/D55287/new/

https://reviews.llvm.org/D55287