Add TODO note

1 files changed, 10 insertions, 1 deletions

diff --git a/Lower.hs b/Lower.hs
index 57ac9ca..cde2e2b 100644
--- a/Lower.hs
+++ b/Lower.hs
@@ -1,3 +1,13 @@
+-- TODO
+-- Use the link register, R14, for the frame pointer (i.e. points to the
+-- link register stack slot, from which argument positions are independent
+-- of spill space). Upon a function call, the frame pointer needs to be
+-- pushed because R14 is overwritten by the call. The value 8 can be
+-- obtained each time through a Li on a new temporary.
+-- If that works out to be impossible, use R12 as the constant 8.
+
+
+
 {-# LANGUAGE TupleSections, MultiWayIf, GeneralizedNewtypeDeriving #-}
 module Lower(lowerIR) where
 
@@ -116,7 +126,6 @@ genTemp = liftM AReg genId
 
 lowerIR :: IRProgram -> AsmProgram'
 lowerIR origProgram =
-    -- TODO: For each function, push and pop the link register
     let res1 = closuresAreParams origProgram
         IRProgram bbs gfds _ = res1