[llvm] r241513 - WebAssembly: add some TODO

[JF Bastien]

Author: jfb
Date: Mon Jul  6 16:41:59 2015
New Revision: 241513

URL: http://llvm.org/viewvc/llvm-project?rev=241513&view=rev
Log:
WebAssembly: add some TODO

Reviewers: sunfish

Subscribers: llvm-commits, jfb

Differential Revision: http://reviews.llvm.org/D10971

Modified:
    llvm/trunk/lib/Target/WebAssembly/README.txt

Modified: llvm/trunk/lib/Target/WebAssembly/README.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/README.txt?rev=241513&r1=241512&r2=241513&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/README.txt (original)
+++ llvm/trunk/lib/Target/WebAssembly/README.txt Mon Jul  6 16:41:59 2015
@@ -12,4 +12,15 @@ binary encoding of WebAssembly itself:
   * 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.
+
 //===---------------------------------------------------------------------===//