[PATCH] D27283: Fix invalid addrspacecast due to combining alloca with global var

[David Majnemer via Phabricator via llvm-commits]

majnemer added inline comments.


================
Comment at: lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp:253-256
+      auto *NewI = GetElementPtrInst::Create(NT->getElementType(), V, Indices);
+      InsertNewInstWith(NewI, *GEP);
+      if (!replacePointer(*GEP, NewI))
+        return false;
----------------
yaxunl wrote:
> majnemer wrote:
> > Is it possible for you to create instructions which you never RAUW?
> Yes, but then these instructions will be removed. The lit test checks that.
It is bad form to create new instructions in instcombine if you aren't sure you will want to keep them.  Please keep in mind that IC is heavily relied upon and shows up several times in the pass pipeline.


https://reviews.llvm.org/D27283