[PATCH] D141747: Resolve a FIXME in MachineCopyPropagation by allowig propagation to subregister uses.

[Owen Anderson via Phabricator via llvm-commits]

resistor added inline comments.


================
Comment at: llvm/lib/CodeGen/MachineCopyPropagation.cpp:604
+      SubregIdx = TRI->getSubRegIndex(CopyDstReg, MOUse.getReg());
+      assert(SubregIdx && "Unable to find index of subregister");
     }
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arsenm wrote:
> This should bail as before rather than assert, the result class might not support the index
Can you explain how that scenario could arise? I'm unable to picture it, and I didn't hit any cases of it in the test suite.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D141747/new/

https://reviews.llvm.org/D141747