Index: llvm/trunk/lib/Target/WebAssembly/README.txt
===================================================================
--- llvm/trunk/lib/Target/WebAssembly/README.txt
+++ llvm/trunk/lib/Target/WebAssembly/README.txt
@@ -12,4 +12,15 @@
   * https://github.com/WebAssembly/design/blob/master/AstSemantics.md
   * https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md
 
+Interesting work that remains to be done:
+* Write a pass to restructurize irreducible control flow. This needs to be done
+  before register allocation to be efficient, because it may duplicate basic
+  blocks and WebAssembly performs register allocation at a whole-function
+  level. Note that LLVM's GPU code has such a pass, but it linearizes control
+  flow (e.g. both sides of branches execute and are masked) which is undesirable
+  for WebAssembly.
+* Basic relooper to expose control flow as an AST.
+* Figure out how to properly use MC for virtual ISAs. This may require some
+  refactoring of MC.
+
 //===---------------------------------------------------------------------===//