[PATCH] D33839: Prevent outlining of basicblock that uses BlockAddress

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: lib/Transforms/Utils/CodeExtractor.cpp:79
+    if (isa<BlockAddress const>(Curr))
+      return false; // even a reference to self is likely to be not compatible
+
----------------
I'm not sure I follow this check.

You can't extract a basic block whose terminator is an indirectbr; in general, you can't efficiently break the relevant CFG edges.  Similarly, you can't extract a block with an indirectbr predecessor.  And extracting a block whose address is taken is likely to lead to unexpected results in other cases for code which abuses block addresses for other uses (like the Linux kernel).

But I can't see why you would want to block extracting a basic block just because it refers to a blockaddress, or a global variable which contains a blockaddress.


Repository:
  rL LLVM

https://reviews.llvm.org/D33839