Implement division and modulo

compiler/src/l3/CPSValueRepresenter.scala

@@ -28,7 +28,7 @@ object CPSValueRepresenter extends (H.Tree => L.Tree) {
 
     case H.If(cond, args, thenC, elseC) =>
       transformIf(cond, args, thenC, elseC)
-    case _ => throw new Exception(tree.getClass.toString)
+    case _ => throw new Exception("Unimplemented: " + tree.getClass.toString)
   }
 
   private def transformIf(cond: L3, args: Seq[H.Atom], thenC: H.Name, elseC: H.Name): L.Tree = {
@@ -101,9 +101,27 @@ object CPSValueRepresenter extends (H.Tree => L.Tree) {
     }
   }
 
+
+
   // Transforms value primitives that take 2 arguments
   private def applyLetPBinary(n: H.Name, prim: L3, x: H.Atom, y: H.Atom, body: H.Tree): L.LetP = {
     val lAtomOne: Either[H.Atom, L.Atom] = Right(L.AtomL(1))
+    
+    // Generates the LetP tree for a brute "untag, apply, retag" operation
+    def rawTree(op: CPS): L.LetP = {
+      // Untag both values
+      tempLetP(CPS.ShiftRight, Seq(Left(x), lAtomOne)) { x1 =>
+        tempLetP(CPS.ShiftRight, Seq(Left(y), lAtomOne)) { y1 =>
+          // Apply the actual operation
+          tempLetP(op, Seq(Right(x1), Right(y1))) { truDiv =>
+            // Retag the result
+            tempLetP(CPS.ShiftLeft, Seq(Right(truDiv), lAtomOne)) { shiftedRes =>
+              L.LetP(n, CPS.Add, Seq(shiftedRes, L.AtomL(1)), apply(body))
+            }
+          }
+        }
+      }
+    }
     prim match {
       case L3.BlockGet => 
         // In theory, x has to be a name, since there cannot be pointer literals
@@ -129,8 +147,8 @@ object CPSValueRepresenter extends (H.Tree => L.Tree) {
         }
 
       // I don't think there is a way to do this in a smart way
-      case L3.IntDiv => ???
-      case L3.IntMod => ???
+      case L3.IntDiv => rawTree(CPS.Div)
+      case L3.IntMod => rawTree(CPS.Mod)
 
       case L3.IntShiftLeft =>
         tempLetP(CPS.Sub, Seq(Left(x), lAtomOne)) { x1 =>