[PATCH] D20555: [MemCpyOpt] Be conservative in the face of returns_twice calls

[Eli Friedman via llvm-commits]

eli.friedman added inline comments.

================
Comment at: lib/Transforms/Scalar/MemCpyOptimizer.cpp:1381
@@ +1380,3 @@
+  if (F.callsFunctionThatReturnsTwice())
+    return false;
+
----------------
I don't think all the optimizations in this pass are affected; memset merging seems pretty safe.  That said, probably not worth the trouble, given how rare functions which call setjmp are.


http://reviews.llvm.org/D20555