Add strings to type system and parser/lexer

[snipe.git] / codegen / codegen.sml

diff --git a/codegen/codegen.sml b/codegen/codegen.sml
index 8a5afe27965b552b3c6e7c4dcdc81abfe1f1a128..de8fa1e7867f5fcc851a1bfb924bb9975ef31c4e 100644 (file)
--- a/codegen/codegen.sml
+++ b/codegen/codegen.sml
@@ -6,430 +6,315 @@
 
 signature CODEGEN =
 sig
 
 signature CODEGEN =
 sig

-  val codegen : Tree.stm list -> x86.insn list
+  val codegen : Tree.stm list -> Blarg.insn list

 end
 
 structure Codegen :> CODEGEN = 
 struct
   structure T = Tree
 end
 
 structure Codegen :> CODEGEN = 
 struct
   structure T = Tree

-  structure X = x86
-
-  (* effect : T.exp -> bool
-   * true iff the given expression has an effect.
-   *)
-  fun effect (T.BINOP(T.DIV, _, _)) = true
-    | effect (T.BINOP(T.MOD, _, _)) = true
-    | effect (T.CALL _) = true
-    | effect (T.BINOP(_, a, b)) = (effect a) orelse (effect b)
-    | effect (T.UNOP (_, a)) = effect a
-    | effect _ = false
+  structure TU = TreeUtils
+  structure X = Blarg
+  structure Tm = Temp

 
   (* hasfixed : T.exp -> bool
 
   (* hasfixed : T.exp -> bool

-   * true iff the given expression has an hasfixed. Somewhat like effect, hmm?
+   * true iff the given expression has an hasfixed.

    *)
    *)

-  fun hasfixed (T.BINOP(T.DIV, _, _)) = true
-    | hasfixed (T.BINOP(T.MOD, _, _)) = true
-    | hasfixed (T.BINOP(T.LSH, _, _)) = true
-    | hasfixed (T.BINOP(T.RSH, _, _)) = true
-    | hasfixed (T.CALL _) = true
+  fun hasfixed (T.CALL _) = true

     | hasfixed (T.BINOP(_, a, b)) = (hasfixed a) orelse (hasfixed b)
     | hasfixed (T.UNOP (_, a)) = hasfixed a
     | hasfixed (T.BINOP(_, a, b)) = (hasfixed a) orelse (hasfixed b)
     | hasfixed (T.UNOP (_, a)) = hasfixed a

+    | hasfixed (T.ALLOC(_)) = true
+    | hasfixed (T.MEMORY (m)) = hasfixed m
+    | hasfixed (T.STMVAR _) = true

     | hasfixed _ = false
 
     | hasfixed _ = false
 

+  (* binophit : X.oper -> X.opc -> T.exp -> T.exp -> X.insn list *)
+  (* binophit d oper e1 e2
+   * generates instructions to achieve d <- e1 oper e2
+   * oper should be something like X.ADD
+   *)
+  fun binophit d oper e1 e2 =
+    let
+      val t = X.TEMP (Tm.new "binop")
+      val i1 = munch_exp d e1
+      val i2 = munch_exp t e2
+(*      val _ = print ("s1 = " ^ Tm.sfx s1 ^ ", s2 = " ^ Tm.sfx s2 ^ ", ") *)
+(*      val _ = print ("rs = " ^ Tm.sfx rs ^ " from " ^ TU.Print.pp_exp e1 ^ " and " ^ TU.Print.pp_exp e2 ^ "\n") *)
+    in
+      [X.COMMENT "binophit" ] @ i1 @ i2 @ [X.INSN (X.AL, oper (d, t)), X.COMMENT "binophit done"]
+    end
+  
+  (* cmphit : X.oper -> X.exp -> X.insn list
+   * cmphit d ex 
+   * generates instructions to set d based on the truth value of ex
+   *)
+  and cmphit d ex =
+    let
+      val (insns, pos, neg) = munch_cond ex
+    in 
+      insns @ [X.INSN (X.AL, X.MOVLIT (d, 0w0)), X.INSN (pos, X.MOVLIT (d, 0w1))]
+    end
+

   (* munch_exp : prex86oper -> T.exp -> prex86insn list *)
   (* munch_exp d e
    * generates instructions to achieve d <- e
    * d must be TEMP(t) or REG(r)
    *)
   (* munch_exp : prex86oper -> T.exp -> prex86insn list *)
   (* munch_exp d e
    * generates instructions to achieve d <- e
    * d must be TEMP(t) or REG(r)
    *)

-  fun munch_exp d (T.CONST(n)) = [X.MOV(d, X.CONST n)]
-    | munch_exp d (T.TEMP(t)) = [X.MOV(d, X.TEMP t)]
-    | munch_exp d (T.ARG(0)) = [X.MOV(d, X.REG X.EDI)]
-    | munch_exp d (T.ARG(1)) = [X.MOV(d, X.REG X.ESI)]
-    | munch_exp d (T.ARG(2)) = [X.MOV(d, X.REG X.EDX)]
-    | munch_exp d (T.ARG(3)) = [X.MOV(d, X.REG X.ECX)]
-    | munch_exp d (T.ARG(4)) = [X.MOV(d, X.REG X.R8D)]
-    | munch_exp d (T.ARG(5)) = [X.MOV(d, X.REG X.R9D)]
-    | munch_exp d (T.ARG(t)) = [X.MOV(d, X.STACKARG (t - 6))]
-    | munch_exp d (T.CALL(name, l)) =  (* Scary demons live here. *)
+  and munch_exp d (T.CONST n) = [X.INSN (X.AL, X.MOVLIT(d, Word.fromLarge n))]
+    | munch_exp d (T.NULLPTR) = [X.INSN (X.AL, X.MOVLIT(d, 0w0))]
+    | munch_exp d (T.TEMP(t)) = [X.INSN (X.AL, X.MOV(d, X.TEMP t))]
+    | munch_exp d (T.ARG(0)) = [X.INSN (X.AL, X.MOV(d, X.REG X.R0))]
+    | munch_exp d (T.ARG(1)) = [X.INSN (X.AL, X.MOV(d, X.REG X.R1))]
+    | munch_exp d (T.ARG(2)) = [X.INSN (X.AL, X.MOV(d, X.REG X.R2))]
+    | munch_exp d (T.ARG(3)) = [X.INSN (X.AL, X.MOV(d, X.REG X.R3))]
+    | munch_exp d (T.ARG(t)) = [X.INSN (X.AL, X.MOV(d, X.STACKARG (t - 4)))]
+    | munch_exp d (T.CALL(name, l)) = (* Scary demons live here. *)

         let
           val nargs = length l
         let
           val nargs = length l

-          val nstack = if (nargs <= 6)
+          val nstack = if (nargs <= 4)

                        then 0
                        then 0

-                       else nargs - 6
-          val stackb = nstack * 8
-          fun argdest 1 = X.REG X.EDI
-            | argdest 2 = X.REG X.ESI
-            | argdest 3 = X.REG X.EDX
-            | argdest 4 = X.REG X.ECX
-            | argdest 5 = X.REG X.R8D
-            | argdest 6 = X.REG X.R9D
-            | argdest n = X.REL (X.RSP, (~(stackb - 8 * (n - 7))))
+                       else nargs - 4
+          val stackb = nstack * 1
+          fun argdest 1 = X.REG X.R0
+            | argdest 2 = X.REG X.R1
+            | argdest 3 = X.REG X.R2
+            | argdest 4 = X.REG X.R3
+            | argdest n = raise ErrorMsg.InternalError "more than 4 args not supported yet" (*X.REL ((X.REG X.RSP, Tm.Quad), (X.CONST (Word32.fromInt (~(stackb - 8 * (n - 7)))), Tm.Quad), 0w1)*)

 
           val dests = List.tabulate (nargs, fn x => argdest (x+1))
           val hf = List.map hasfixed l
 
           val dests = List.tabulate (nargs, fn x => argdest (x+1))
           val hf = List.map hasfixed l

-          val (d_hf, exps_hf) = ListPair.unzip (ListPair.foldr
+          val (d_hf, l_hf) = ListPair.unzip (ListPair.foldr

             (fn (a,b,c) => if b then a::c else c)
             nil
             (ListPair.zip (dests,l), hf)
           )
             (fn (a,b,c) => if b then a::c else c)
             nil
             (ListPair.zip (dests,l), hf)
           )

-          val (d_nohf, exps_nohf) = ListPair.unzip (ListPair.foldr
+          val (d_nohf, l_nohf) = ListPair.unzip (ListPair.foldr

             (fn (a,b,c) => if b then c else a::c)
             nil
             (ListPair.zip (dests,l), hf)
           )
             (fn (a,b,c) => if b then c else a::c)
             nil
             (ListPair.zip (dests,l), hf)
           )

-          val temps = List.tabulate (List.length d_hf, fn x => Temp.new(Int.toString x ^ " arg"))
+          val temps = List.map (fn _ => Temp.new ("arg")) l_hf

           val argevals_hf = List.map
             (fn (t,exp) => munch_exp (X.TEMP t) exp)
           val argevals_hf = List.map
             (fn (t,exp) => munch_exp (X.TEMP t) exp)

-            (ListPair.zip (temps, exps_hf))
+            (ListPair.zip (temps, l_hf))

           val argpushes = List.map
           val argpushes = List.map

-            (fn (dest, t) => [(X.MOV (dest, X.TEMP t))])
+            (fn (dest, t) => [X.INSN (X.AL, X.MOV (dest, X.TEMP t))])

             (ListPair.zip (d_hf, temps))
           val argevals_nohf = List.map
             (fn (d,exp) => munch_exp d exp)
             (ListPair.zip (d_hf, temps))
           val argevals_nohf = List.map
             (fn (d,exp) => munch_exp d exp)

-            (ListPair.zip (d_nohf, exps_nohf))
+            (ListPair.zip (d_nohf, l_nohf))
+          
+          val t_stackb = Temp.new ("stackb")
+          val t_target = Temp.new ("target")

         in
           List.concat argevals_hf @ 
           List.concat argpushes @
           List.concat argevals_nohf @
         in
           List.concat argevals_hf @ 
           List.concat argpushes @
           List.concat argevals_nohf @

-          [ X.SIZE (X.Qword, X.SUB (X.REG X.RSP, X.CONST (Word32.fromInt stackb))),
-            X.CALL (name, nargs),
-            X.SIZE (X.Qword, X.ADD (X.REG X.RSP, X.CONST (Word32.fromInt stackb))),
-            X.MOV (d, X.REG X.EAX) ]   (* Finally! *)
-        end
-    | munch_exp d (T.BINOP(T.ADD, e1, T.CONST 0w0)) = munch_exp d e1
-    | munch_exp d (T.BINOP(T.ADD, T.CONST 0w0, e1)) = munch_exp d e1
-    | munch_exp d (T.BINOP(T.ADD, e1, T.CONST n)) = (munch_exp d e1) @ [X.ADD(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.ADD, T.CONST n, e1)) = (munch_exp d e1) @ [X.ADD(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.ADD, e1, T.TEMP t)) = (munch_exp d e1) @ [X.ADD(d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.ADD, T.TEMP t, e2)) = (munch_exp d e2) @ [X.ADD(d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.ADD, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("add"))
-        in
-          (munch_exp d e1) @ (munch_exp t1 e2) @ [X.ADD(d, t1)]
-        end
-    | munch_exp d (T.BINOP(T.SUB, T.CONST 0w0, e1)) = (munch_exp d e1) @ [X.NEG d]
-    | munch_exp d (T.BINOP(T.SUB, e1, T.CONST 0w0)) = munch_exp d e1
-    | munch_exp d (T.BINOP(T.SUB, e1, T.CONST(n))) = (munch_exp d e1) @ [X.SUB(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.SUB, e1, T.TEMP t)) = (munch_exp d e1) @ [X.SUB(d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.SUB, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("sub"))
-        in
-          (munch_exp d e1) @ (munch_exp t1 e2) @ [X.SUB(d, t1)]
-        end
-    | munch_exp d (T.BINOP(T.MUL, T.TEMP t, T.CONST n)) = [X.IMUL3(d, X.TEMP t, n)]
-    | munch_exp d (T.BINOP(T.MUL, T.CONST n, T.TEMP t)) = [X.IMUL3(d, X.TEMP t, n)]
-    | munch_exp d (T.BINOP(T.MUL, e1, T.CONST 0w1)) = munch_exp d e1
-    | munch_exp d (T.BINOP(T.MUL, T.CONST 0w1, e1)) = munch_exp d e1
-    | munch_exp d (T.BINOP(T.MUL, e1, T.CONST n)) = (munch_exp d e1) @ [X.IMUL(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.MUL, T.CONST n, e1)) = (munch_exp d e1) @ [X.IMUL(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.MUL, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("mul"))
-        in
-          (munch_exp d e1) @ (munch_exp t1 e2) @ [X.IMUL(d, t1)]
-        end
-    | munch_exp d (T.BINOP(T.DIV, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("div"))
-        in
-          (munch_exp t1 e1) @ (munch_exp d e2) @
-          [X.MOV (X.REG X.EAX, t1), X.CLTD, X.IDIV d, X.MOV (d, X.REG X.EAX)]
-        end
-    | munch_exp d (T.BINOP(T.MOD, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("mod"))
-        in
-          (munch_exp t1 e1) @ (munch_exp d e2) @
-          [X.MOV (X.REG X.EAX, t1), X.CLTD, X.IDIV d, X.MOV (d, X.REG X.EDX)]
-        end
-    | munch_exp d (T.BINOP(T.LSH, e1, T.CONST n)) = (munch_exp d e1) @ [X.SAL (d, X.CONST (n mod 0w32))]
-    | munch_exp d (T.BINOP(T.LSH, e1, T.TEMP t)) = (munch_exp d e1) @ [X.MOV (X.REG X.ECX, X.TEMP t), X.SAL (d, X.REG X.ECX)]
-    | munch_exp d (T.BINOP(T.LSH, e1, e2)) =
-        let
-          val t = X.TEMP (Temp.new ("lsh"))
-        in
-          (munch_exp d e1) @ (munch_exp t e2) @ [X.MOV (X.REG X.ECX, t), X.SAL (d, X.REG X.ECX)]
-        end
-    | munch_exp d (T.BINOP(T.RSH, e1, T.CONST n)) = (munch_exp d e1) @ [X.SAR (d, X.CONST (n mod 0w32))]
-    | munch_exp d (T.BINOP(T.RSH, e1, T.TEMP t)) = (munch_exp d e1) @ [X.MOV (X.REG X.ECX, X.TEMP t), X.SAR (d, X.REG X.ECX)]
-    | munch_exp d (T.BINOP(T.RSH, e1, e2)) =
-        let
-          val t = X.TEMP (Temp.new ("rsh"))
-        in
-          (munch_exp d e1) @ (munch_exp t e2) @ [X.MOV (X.REG X.ECX, t), X.SAR (d, X.REG X.ECX)]
-        end
-    | munch_exp d (T.BINOP(T.BITAND, T.CONST n, e1)) = (munch_exp d e1) @ [X.AND (d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.BITAND, e1, T.CONST n)) = (munch_exp d e1) @ [X.AND (d, X.CONST n)] 
-    | munch_exp d (T.BINOP(T.BITAND, T.TEMP t, e1)) = (munch_exp d e1) @ [X.AND (d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.BITAND, e1, T.TEMP t)) = (munch_exp d e1) @ [X.AND (d, X.TEMP t)] 
-    | munch_exp d (T.BINOP(T.BITAND, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("bitand"))
-        in
-          (munch_exp d e1) @ (munch_exp t1 e2) @ [X.AND(d, t1)]
-        end
-    | munch_exp d (T.BINOP(T.BITOR, T.CONST n, e1)) = (munch_exp d e1) @ [X.OR (d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.BITOR, e1, T.CONST n)) = (munch_exp d e1) @ [X.OR (d, X.CONST n)] 
-    | munch_exp d (T.BINOP(T.BITOR, T.TEMP t, e1)) = (munch_exp d e1) @ [X.OR (d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.BITOR, e1, T.TEMP t)) = (munch_exp d e1) @ [X.OR (d, X.TEMP t)] 
-    | munch_exp d (T.BINOP(T.BITOR, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("bitor"))
-        in
-          (munch_exp d e1) @ (munch_exp t1 e2) @ [X.OR(d, t1)]
+          [ X.INSN (X.AL, X.MOVLIT (X.TEMP t_stackb, Word.fromInt stackb)),
+            X.INSN (X.AL, X.MOVSYM (X.TEMP t_target, name)),
+            X.INSN (X.AL, X.SUB (X.REG X.SP, X.TEMP t_stackb)),
+            X.INSN (X.AL, X.CALL (X.REG X.SP, X.TEMP t_target, nargs)),
+            X.INSN (X.AL, X.ADD (X.REG X.SP, X.TEMP t_stackb)),
+            X.INSN (X.AL, X.MOV (d, X.REG X.R0))]

         end
         end

-    | munch_exp d (T.BINOP(T.BITXOR, T.CONST n, e1)) = (munch_exp d e1) @ [X.XOR (d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.BITXOR, e1, T.CONST n)) = (munch_exp d e1) @ [X.XOR (d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.BITXOR, T.TEMP t, e1)) = (munch_exp d e1) @ [X.XOR (d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.BITXOR, e1, T.TEMP t)) = (munch_exp d e1) @ [X.XOR (d, X.TEMP t)]
+    (*| munch_exp d (T.BINOP(T.ADD, e1, T.CONST n)) = binophit_c d X.ADD e1 n
+    | munch_exp d (T.BINOP(T.ADD, T.CONST n, e1)) = binophit_c d X.ADD e1 n
+    | munch_exp d (T.BINOP(T.ADD, e1, T.TEMP t)) = binophit_t d X.ADD e1 t
+    | munch_exp d (T.BINOP(T.ADD, T.TEMP t, e1)) = binophit_t d X.ADD e1 t*)
+    | munch_exp d (T.BINOP(T.ADD, e1, e2)) = binophit d X.ADD e1 e2
+
+    (*| munch_exp d (T.BINOP(T.SUB, e1, T.CONST n)) = binophit_c d X.SUB e1 n
+    | munch_exp d (T.BINOP(T.SUB, e1, T.TEMP t)) = binophit_t d X.SUB e1 t*)
+    | munch_exp d (T.BINOP(T.SUB, e1, e2)) = binophit d X.SUB e1 e2
+    | munch_exp d (T.BINOP(T.MUL, e1, e2)) = munch_exp d (T.CALL (Symbol.symbol "__blarg_mul", [e1, e2]))
+    | munch_exp d (T.BINOP(T.DIV, e1, e2)) = munch_exp d (T.CALL (Symbol.symbol "__blarg_div", [e1, e2]))
+    | munch_exp d (T.BINOP(T.MOD, e1, e2)) = munch_exp d (T.CALL (Symbol.symbol "__blarg_mod", [e1, e2]))
+    | munch_exp d (T.BINOP(T.LSH, e1, e2)) = binophit d X.SHL e1 e2
+    | munch_exp d (T.BINOP(T.RSH, e1, e2)) = binophit d X.SHR e1 e2
+    | munch_exp d (T.BINOP(T.BITAND, e1, e2)) = binophit d X.AND e1 e2
+    | munch_exp d (T.BINOP(T.BITOR, e1, e2)) = munch_exp d (T.UNOP (T.BITNOT, T.BINOP (T.BITAND, T.UNOP (T.BITNOT, e1), T.UNOP (T.BITNOT, e2))))

     | munch_exp d (T.BINOP(T.BITXOR, e1, e2)) =
     | munch_exp d (T.BINOP(T.BITXOR, e1, e2)) =

-        let
-          val t1 = X.TEMP (Temp.new ("bitxor"))
-        in
-          (munch_exp d e1) @ (munch_exp t1 e2) @ [X.XOR(d, t1)]
-        end
+        munch_exp d (T.BINOP(T.BITOR, T.BINOP(T.BITAND, e1, T.UNOP(T.BITNOT, e2)),
+                                      T.BINOP(T.BITAND, e2, T.UNOP(T.BITNOT, e1))))
+

     | munch_exp d (a as T.BINOP(T.LOGAND, e1, e2)) =
         let
           val (insn1, pos1, neg1) = munch_cond e1
           val (insn2, pos2, neg2) = munch_cond e2
     | munch_exp d (a as T.BINOP(T.LOGAND, e1, e2)) =
         let
           val (insn1, pos1, neg1) = munch_cond e1
           val (insn2, pos2, neg2) = munch_cond e2

-          val t1 = X.TEMP (Temp.new("logand 1"))
-          val t2 = X.TEMP (Temp.new("logand 2"))

           val l = Label.new ()
         in
           val l = Label.new ()
         in

-          if (effect e2 orelse (length insn2 > 10))
-          then (insn1) @
-               [X.SETcc(pos1, t1), X.Jcc (neg1, l)] @
-               (insn2) @
-               [X.SETcc(pos2, t1), X.LABEL l, X.MOVZB(d, t1)]
-          else insn1 @ [X.SETcc (pos1, t1)] @ insn2 @ [X.SETcc (pos2, t2), X.SIZE(X.Byte, X.AND(t1, t2)), X.MOVZB(d, t1)]
+          (insn1) @
+          [X.INSN (X.AL, X.MOVLIT (d, 0w0)),
+           X.INSN (neg1, X.MOVLBL (X.REG X.PC, l))] @
+          (insn2) @
+          [X.INSN (pos2, X.MOVLIT (d, 0w1)),
+           X.LABEL l]

         end
     | munch_exp d (a as T.BINOP(T.LOGOR, e1, e2)) =
         let
           val (insn1, pos1, neg1) = munch_cond e1
           val (insn2, pos2, neg2) = munch_cond e2
         end
     | munch_exp d (a as T.BINOP(T.LOGOR, e1, e2)) =
         let
           val (insn1, pos1, neg1) = munch_cond e1
           val (insn2, pos2, neg2) = munch_cond e2

-          val t1 = X.TEMP (Temp.new("logor 1"))
-          val t2 = X.TEMP (Temp.new("logor 2"))
+          val t1 = X.TEMP (Tm.new "logand 1")
+          val t2 = X.TEMP (Tm.new "logand 2")

           val l = Label.new ()
         in
           val l = Label.new ()
         in

-          if (effect e2 orelse (length insn2 > 10))
-          then (insn1) @
-               [X.SETcc(pos1, t1), X.Jcc (pos1, l)] @
-               (insn2) @
-               [X.SETcc(pos2, t1), X.LABEL l, X.MOVZB(d, t1)]
-          else insn1 @ [X.SETcc (pos1, t1)] @ insn2 @ [X.SETcc (pos2, t2), X.SIZE(X.Byte, X.OR(t1, t2)), X.MOVZB(d, t1)]
+          (insn1) @
+          [X.INSN (X.AL, X.MOVLIT (d, 0w0)),
+           X.INSN (pos1, X.MOVLIT (d, 0w1)),
+           X.INSN (pos1, X.MOVLBL (X.REG X.PC, l))] @
+          (insn2) @
+          [X.INSN (pos2, X.MOVLIT (d, 0w1)),
+           X.LABEL l]

         end
         end

-    | munch_exp d (a as T.BINOP(T.EQ, _, _)) =
-        let val (insns, pos, neg) = munch_cond a in insns @ [X.SETcc (pos, d), X.MOVZB(d, d)] end
-    | munch_exp d (a as T.BINOP(T.NEQ, _, _)) =
-        let val (insns, pos, neg) = munch_cond a in insns @ [X.SETcc (pos, d), X.MOVZB(d, d)] end
-    | munch_exp d (a as T.BINOP(T.LE, _, _)) =
-        let val (insns, pos, neg) = munch_cond a in insns @ [X.SETcc (pos, d), X.MOVZB(d, d)] end
-    | munch_exp d (a as T.BINOP(T.LT, _, _)) =
-        let val (insns, pos, neg) = munch_cond a in insns @ [X.SETcc (pos, d), X.MOVZB(d, d)] end
-    | munch_exp d (a as T.BINOP(T.GE, _, _)) =
-        let val (insns, pos, neg) = munch_cond a in insns @ [X.SETcc (pos, d), X.MOVZB(d, d)] end
-    | munch_exp d (a as T.BINOP(T.GT, _, _)) =
-        let val (insns, pos, neg) = munch_cond a in insns @ [X.SETcc (pos, d), X.MOVZB(d, d)] end
-    | munch_exp d (T.UNOP(T.NEG, T.CONST n)) = [X.MOV (d, X.CONST (~n))]
-    | munch_exp d (T.UNOP(T.NEG, e1)) = (munch_exp d e1) @ [X.NEG d]
-    | munch_exp d (T.UNOP(T.BITNOT, T.CONST n)) = [X.MOV (d, X.CONST (Word32.notb n))]
-    | munch_exp d (T.UNOP(T.BITNOT, e1)) = (munch_exp d e1) @ [X.NOT d]
-    | munch_exp d (T.UNOP(T.BANG, T.CONST n)) = if (n = 0w0) then [X.MOV (d, X.CONST 0w1)] else [X.MOV (d, X.CONST 0w0)]
-    | munch_exp d (T.UNOP(T.BANG, e)) = 
+    | munch_exp d (a as T.BINOP(T.EQ, _, _)) = cmphit d a
+    | munch_exp d (a as T.BINOP(T.NEQ, _, _)) = cmphit d a
+    | munch_exp d (a as T.BINOP(T.LE, _, _)) = cmphit d a
+    | munch_exp d (a as T.BINOP(T.LT, _, _)) = cmphit d a
+    | munch_exp d (a as T.BINOP(T.GE, _, _)) = cmphit d a
+    | munch_exp d (a as T.BINOP(T.GT, _, _)) = cmphit d a
+    | munch_exp d (a as T.BINOP(T.BE, _, _)) = cmphit d a
+
+    | munch_exp d (T.UNOP(T.NEG, e1)) =

         let
         let

-          val (insns, pos, neg) = munch_cond e
+          val t = Temp.new "-val"
+          val i = munch_exp (X.TEMP t) e1

         in
         in

-          insns @ [X.SETcc (neg, d), X.MOVZB(d, d)]
+          (i) @
+          [X.INSN (X.AL, X.MOVLIT (d, 0w0)),
+           X.INSN (X.AL, X.SUB (d, X.TEMP t))]

         end
         end

-  (* munch_cond : T.exp -> X.insn list * X.cond * X.cond
-   * munch_cond stm generates code to set flags, and then returns a conditional
-   * to test if the expression was true and for if it was false.
-   *)
-  and munch_cond (T.UNOP (T.BANG, e)) =
+    | munch_exp d (T.UNOP(T.BITNOT, e1)) = let val i = munch_exp d e1 in i @ [X.INSN (X.AL, X.NOT (d, d))] end
+    | munch_exp d (T.UNOP(T.BANG, e)) = 

         let
           val (insns, pos, neg) = munch_cond e
         in
         let
           val (insns, pos, neg) = munch_cond e
         in

-          (insns, neg, pos)
-        end
-    | munch_cond (T.BINOP(T.NEQ, T.TEMP t, T.CONST n)) = ([X.CMP(X.TEMP t, X.CONST n)], X.NE, X.E)
-    | munch_cond (T.BINOP(T.NEQ, T.CONST n, T.TEMP t)) = ([X.CMP(X.TEMP t, X.CONST n)], X.NE, X.E)
-    | munch_cond (T.BINOP(T.NEQ, T.CONST n, e1)) =
-        let val t = X.TEMP (Temp.new ("const neq")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.NE, X.E) end
-    | munch_cond (T.BINOP(T.NEQ, e1, T.CONST n)) =
-        let val t = X.TEMP (Temp.new ("const neq")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.NE, X.E) end
-    | munch_cond (T.BINOP(T.NEQ, T.TEMP t, e1)) =
-        let val t1 = X.TEMP (Temp.new ("const neq")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.NE, X.E) end
-    | munch_cond (T.BINOP(T.NEQ, e1, T.TEMP t)) =
-        let val t1 = X.TEMP (Temp.new ("const neq")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.NE, X.E) end
-    | munch_cond (T.BINOP(T.NEQ, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("var neq 1"))
-          val t2 = X.TEMP (Temp.new ("var neq 2"))
-        in
-          (munch_exp t1 e1 @ munch_exp t2 e2 @
-           [X.CMP(t1, t2)], X.NE, X.E)
-        end
-    | munch_cond (T.BINOP(T.EQ, T.TEMP t, T.CONST n)) = ([X.CMP(X.TEMP t, X.CONST n)], X.E, X.NE)
-    | munch_cond (T.BINOP(T.EQ, T.CONST n, T.TEMP t)) = ([X.CMP(X.TEMP t, X.CONST n)], X.E, X.NE)
-    | munch_cond (T.BINOP(T.EQ, T.CONST n, e1)) =
-        let val t = X.TEMP (Temp.new ("const eq")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.E, X.NE) end
-    | munch_cond (T.BINOP(T.EQ, e1, T.CONST n)) =
-        let val t = X.TEMP (Temp.new ("const eq")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.E, X.NE) end
-    | munch_cond (T.BINOP(T.EQ, T.TEMP t, e1)) =
-        let val t1 = X.TEMP (Temp.new ("const eq")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.E, X.NE) end
-    | munch_cond (T.BINOP(T.EQ, e1, T.TEMP t)) =
-        let val t1 = X.TEMP (Temp.new ("const eq")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.E, X.NE) end
-    | munch_cond (T.BINOP(T.EQ, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("var eq 1"))
-          val t2 = X.TEMP (Temp.new ("var eq 2"))
-        in
-          (munch_exp t1 e1 @ munch_exp t2 e2 @
-           [X.CMP(t1, t2)], X.E, X.NE)
+          insns @
+          [X.INSN (X.AL, X.MOVLIT (d, 0w0)),
+           X.INSN (neg, X.MOVLIT (d, 0w1))]

         end
         end

-    | munch_cond (T.BINOP(T.LE, T.TEMP t, T.CONST n)) = ([X.CMP(X.TEMP t, X.CONST n)], X.LE, X.G)
-    | munch_cond (T.BINOP(T.LE, T.CONST n, T.TEMP t)) = ([X.CMP(X.TEMP t, X.CONST n)], X.GE, X.L)
-    | munch_cond (T.BINOP(T.LE, T.CONST n, e1)) =
-        let val t = X.TEMP (Temp.new ("const le")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.GE, X.L) end
-    | munch_cond (T.BINOP(T.LE, e1, T.CONST n)) =
-        let val t = X.TEMP (Temp.new ("const le")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.LE, X.G) end
-    | munch_cond (T.BINOP(T.LE, T.TEMP t, e1)) =
-        let val t1 = X.TEMP (Temp.new ("const le")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.GE, X.L) end
-    | munch_cond (T.BINOP(T.LE, e1, T.TEMP t)) =
-        let val t1 = X.TEMP (Temp.new ("const le")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.LE, X.G) end
-    | munch_cond (T.BINOP(T.LE, e1, e2)) =
+    | munch_exp d (T.MEMORY (e1)) =

         let
         let

-          val t1 = X.TEMP (Temp.new ("var le 1"))
-          val t2 = X.TEMP (Temp.new ("var le 2"))
+          val a = X.TEMP (Temp.new "addr")
+          val i = munch_exp a e1

         in
         in

-          (munch_exp t1 e1 @ munch_exp t2 e2 @
-           [X.CMP(t1, t2)], X.LE, X.G)
+          i @
+          [X.INSN (X.AL, X.LDR (d, a))]

         end
         end

-    | munch_cond (T.BINOP(T.LT, T.TEMP t, T.CONST n)) = ([X.CMP(X.TEMP t, X.CONST n)], X.L, X.GE)
-    | munch_cond (T.BINOP(T.LT, T.CONST n, T.TEMP t)) = ([X.CMP(X.TEMP t, X.CONST n)], X.G, X.LE)
-    | munch_cond (T.BINOP(T.LT, T.CONST n, e1)) =
-        let val t = X.TEMP (Temp.new ("const lt")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.G, X.LE) end
-    | munch_cond (T.BINOP(T.LT, e1, T.CONST n)) =
-        let val t = X.TEMP (Temp.new ("const lt")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.L, X.GE) end
-    | munch_cond (T.BINOP(T.LT, T.TEMP t, e1)) =
-        let val t1 = X.TEMP (Temp.new ("const lt")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.G, X.LE) end
-    | munch_cond (T.BINOP(T.LT, e1, T.TEMP t)) =
-        let val t1 = X.TEMP (Temp.new ("const lt")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.L, X.GE) end
-    | munch_cond (T.BINOP(T.LT, e1, e2)) =
+    
+    | munch_exp d (T.ALLOC(exp)) =

         let
         let

-          val t1 = X.TEMP (Temp.new ("var lt 1"))
-          val t2 = X.TEMP (Temp.new ("var lt 2"))
+          val t1 = Temp.new "alloc"
+          val l1 = Label.new()
+          val einsn = munch_exp (X.TEMP t1) exp
+          val insns = munch_exp d (T.CALL (Symbol.symbol "calloc", [T.TEMP t1, T.CONST 0w1]))

         in
         in

-          (munch_exp t1 e1 @ munch_exp t2 e2 @
-           [X.CMP(t1, t2)], X.L, X.GE)
+          einsn @ insns 

         end
         end

-    | munch_cond (T.BINOP(T.GT, T.TEMP t, T.CONST n)) = ([X.CMP(X.TEMP t, X.CONST n)], X.G, X.LE)
-    | munch_cond (T.BINOP(T.GT, T.CONST n, T.TEMP t)) = ([X.CMP(X.TEMP t, X.CONST n)], X.L, X.GE)
-    | munch_cond (T.BINOP(T.GT, e1, T.CONST n)) =
-        let val t = X.TEMP (Temp.new ("const gt")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.G, X.LE) end
-    | munch_cond (T.BINOP(T.GT, T.CONST n, e1)) =
-        let val t = X.TEMP (Temp.new ("const gt")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.L, X.GE) end
-    | munch_cond (T.BINOP(T.GT, e1, T.TEMP t)) =
-        let val t1 = X.TEMP (Temp.new ("const gt")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.G, X.LE) end
-    | munch_cond (T.BINOP(T.GT, T.TEMP t, e1)) =
-        let val t1 = X.TEMP (Temp.new ("const gt")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.L, X.GE) end
-    | munch_cond (T.BINOP(T.GT, e1, e2)) =
+(*    | munch_exp d (T.COND(c, T.CONST n1, T.CONST n2)) = let val (i,p,n) = munch_cond c in ((X.MOV (d, X.CONST n1))::i) @ [X.CMOVcc (p, d, X.CONST n2)] end *)
+    | munch_exp d (T.COND(c,e1,e2)) =

         let
         let

-          val t1 = X.TEMP (Temp.new ("var gt 1"))
-          val t2 = X.TEMP (Temp.new ("var gt 2"))
+          val (insns, pos, neg) = munch_cond c
+          val l1 = Label.new()
+          val l2 = Label.new()
+          val i1 = munch_exp d e1
+          val i2 = munch_exp d e2
+(*          val _ = print ("cond: size " ^ Tm.sfx s1 ^ " from " ^ TU.Print.pp_exp e1 ^ ", " ^ Tm.sfx s2 ^ " from " ^ TU.Print.pp_exp e2 ^ "\n") *)

         in
         in

-          (munch_exp t1 e1 @ munch_exp t2 e2 @
-           [X.CMP(t1, t2)], X.G, X.LE)
+          insns @
+          [X.INSN (neg, X.MOVLBL (X.REG X.PC, l1))] @
+          i1 @
+          [X.INSN (X.AL, X.MOVLBL (X.REG X.PC, l2)),
+           X.LABEL l1] @
+          i2 @
+          [X.LABEL l2]

         end
         end

-    | munch_cond (T.BINOP(T.GE, T.TEMP t, T.CONST n)) = ([X.CMP(X.TEMP t, X.CONST n)], X.GE, X.L)
-    | munch_cond (T.BINOP(T.GE, T.CONST n, T.TEMP t)) = ([X.CMP(X.TEMP t, X.CONST n)], X.LE, X.G)
-    | munch_cond (T.BINOP(T.GE, e1, T.CONST n)) =
-        let val t = X.TEMP (Temp.new ("const ge")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.GE, X.L) end
-    | munch_cond (T.BINOP(T.GE, T.CONST n, e1)) =
-        let val t = X.TEMP (Temp.new ("const ge")) in (munch_exp t e1 @ [X.CMP(t, X.CONST n)], X.LE, X.G) end
-    | munch_cond (T.BINOP(T.GE, e1, T.TEMP t)) =
-        let val t1 = X.TEMP (Temp.new ("const ge")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.GE, X.L) end
-    | munch_cond (T.BINOP(T.GE, T.TEMP t, e1)) =
-        let val t1 = X.TEMP (Temp.new ("const ge")) in (munch_exp t1 e1 @ [X.CMP(t1, X.TEMP t)], X.LE, X.G) end
-    | munch_cond (T.BINOP(T.GE, e1, e2)) =
-        let
-          val t1 = X.TEMP (Temp.new ("var ge 1"))
-          val t2 = X.TEMP (Temp.new ("var ge 2"))
-        in
-          (munch_exp t1 e1 @ munch_exp t2 e2 @
-           [X.CMP(t1, t2)], X.GE, X.L)
-        end
-    | munch_cond (T.BINOP(T.LOGOR, e1, e2)) =
-        let
-          val (insn1, pos1, neg1) = munch_cond e1
-          val (insn2, pos2, neg2) = munch_cond e2
-          val t1 = X.TEMP (Temp.new("logor c 1"))
-          val t2 = X.TEMP (Temp.new("logor c 2"))
-          val l = Label.new ()
-        in
-          if (effect e2 orelse (length insn2 > 10))
-          then ((insn1) @
-                [X.SETcc (pos1, t1), X.Jcc (pos1, l)] @
-                (insn2) @
-                [X.SETcc (pos2, t1), X.LABEL l, X.SIZE (X.Byte, X.TEST (t1, t1))],
-                X.NE, X.E)
-          else (insn1 @ [X.SETcc (pos1, t1)] @ insn2 @ [X.SETcc (pos2, t2), X.SIZE(X.Byte, X.OR(t1, t2))], X.NE, X.E)
-        end
-    | munch_cond (T.BINOP(T.LOGAND, e1, e2)) =
+    | munch_exp d (T.STMVAR (sl, e)) = let val i = munch_exp d e in List.concat (map munch_stm sl) @ i end
+
+  and condhit e1 e2 (pos, neg) =
+    let
+      val t1 = X.TEMP (Temp.new ("var cond 1"))
+      val t2 = X.TEMP (Temp.new ("var cond 2"))
+      val i1 = munch_exp t1 e1
+      val i2 = munch_exp t2 e2
+    in
+      (i1 @ i2 @ [X.INSN (X.AL, X.SUBS (t1, t2))], pos, neg)
+    end
+
+  (* munch_cond : T.exp -> X.insn list * X.cond * X.cond
+   * munch_cond stm generates code to set flags, and then returns a conditional
+   * to test if the expression was true and for if it was false.
+   *)
+  and munch_cond (T.UNOP (T.BANG, e)) =

         let
         let

-          val (insn1, pos1, neg1) = munch_cond e1
-          val (insn2, pos2, neg2) = munch_cond e2
-          val t1 = X.TEMP (Temp.new("logand c 1"))
-          val t2 = X.TEMP (Temp.new("logand c 2"))
-          val l = Label.new ()
+          val (insns, pos, neg) = munch_cond e

         in
         in

-          if (effect e2 orelse (length insn2 > 10))
-          then ((insn1) @
-                [X.SETcc (pos1, t1), X.Jcc (neg1, l)] @
-                (insn2) @
-                [X.SETcc (pos2, t1), X.LABEL l, X.SIZE (X.Byte, X.TEST (t1, t1))],
-                X.NE, X.E)
-          else (insn1 @ [X.SETcc (pos1, t1)] @ insn2 @ [X.SETcc (pos2, t2), X.SIZE(X.Byte, X.AND(t1, t2))], X.NE, X.E)
+          (insns, neg, pos)

         end
         end

+    | munch_cond (T.BINOP(T.NEQ, e1, e2)) = condhit e1 e2 (X.NE, X.EQ)
+    | munch_cond (T.BINOP(T.EQ, e1, e2)) =  condhit e1 e2 (X.EQ, X.NE)
+    | munch_cond (T.BINOP(T.LE, e1, e2)) =  condhit e1 e2 (X.LE, X.GT)
+    | munch_cond (T.BINOP(T.LT, e1, e2)) =  condhit e1 e2 (X.LT, X.GE)
+    | munch_cond (T.BINOP(T.GT, e1, e2)) =  condhit e1 e2 (X.GT, X.LE)
+    | munch_cond (T.BINOP(T.GE, e1, e2)) =  condhit e1 e2 (X.GE, X.LT)
+
+    | munch_cond (T.BINOP(T.BE, e1, e2)) = raise ErrorMsg.InternalError "memory safety not supported"
+

     | munch_cond e =
       let
         val t = X.TEMP (Temp.new ("munch c"))
     | munch_cond e =
       let
         val t = X.TEMP (Temp.new ("munch c"))

+        val i = munch_exp t e
+      in
+        (i @ [ X.INSN (X.AL, X.MOVS (t,t)) ], X.NE, X.EQ)
+      end
+
+  (* munch_lval : T.exp -> X.operand
+   * Takes an expression that has been typechecked as being a valid lvalue and a location of a datum, and then returns an instruction list to store.
+   *)
+  and munch_lval (T.TEMP t) oper = [X.INSN (X.AL, X.MOV (X.TEMP t, oper))]
+    | munch_lval (T.MEMORY m) oper = 
+      let
+        val t = X.TEMP (Tm.new "lv addr")
+        val i = munch_exp t m

       in
       in

-        (munch_exp t e @ [ X.TEST (t,t) ], X.NE, X.E)
+        i @
+        [X.INSN (X.AL, X.STO (t, oper))]

       end
       end

+    | munch_lval _ _ = raise ErrorMsg.InternalError "That wasn't really a valid lvalue..."

 
   (* munch_stm : T.stm -> X.insn list *)
   (* munch_stm stm generates code to execute stm *)
 
   (* munch_stm : T.stm -> X.insn list *)
   (* munch_stm stm generates code to execute stm *)

-  fun munch_stm (T.MOVE (T.TEMP t, a as T.TEMP _)) = munch_exp (X.TEMP t) a
-    | munch_stm (T.MOVE (T.TEMP t, a as T.CONST _)) = munch_exp (X.TEMP t) a
-    | munch_stm (T.MOVE (T.TEMP t, a as T.ARG _)) = munch_exp (X.TEMP t) a
+  and munch_stm (T.MOVE (T.TEMP t1, T.TEMP t2)) = [X.INSN (X.AL, X.MOV(X.TEMP t1, X.TEMP t2))]
+    | munch_stm (T.MOVE (T.TEMP t, T.CONST n)) = [X.INSN (X.AL, X.MOVLIT(X.TEMP t, Word.fromLarge n))]
+    | munch_stm (T.MOVE (T.TEMP t, a as T.ARG (an))) =
+        let
+          val i = munch_exp (X.TEMP t) a
+        in
+          i
+        end

     | munch_stm (T.MOVE (T.TEMP t, a as T.CALL _)) = munch_exp (X.TEMP t) a
     | munch_stm (T.MOVE (T.TEMP t, a as T.CALL _)) = munch_exp (X.TEMP t) a

-    | munch_stm (T.MOVE(T.TEMP t1, e2)) =
+    | munch_stm (T.MOVE (a, e2)) =

         let
         let

-          val t = Temp.new ("assign")
+          val t = X.TEMP (Temp.new ("assign"))
+          val i = munch_exp t e2
+          val li = munch_lval a t

         in
         in

-          munch_exp (X.TEMP t) e2
-          @ [X.MOV(X.TEMP t1, X.TEMP t)]
+          i @ li

         end
         end

-    | munch_stm (T.MOVE(_, _)) =
-        raise ErrorMsg.InternalError "Incorrect first operand for T.MOVE?"

     | munch_stm (T.RETURN(e)) =
         let
     | munch_stm (T.RETURN(e)) =
         let

-          val t = Temp.new ("retval")
+          val t = X.TEMP (Temp.new ("retval"))
+          val i = munch_exp t e

         in
         in

-          munch_exp (X.TEMP t) e
-          @ [X.MOV(X.REG X.EAX, X.TEMP t), X.RET]
+          i @ [X.INSN (X.AL, X.MOV(X.REG X.R0, t)), X.INSN (X.AL, X.POP (X.REG X.SP, X.REG X.PC))]

         end
         end

-    | munch_stm (T.LABEL(l)) = [X.LABEL l]
-    | munch_stm (T.JUMP(l)) = [X.JMP l]
+    | munch_stm (T.LABEL l) = [X.LABEL l]
+    | munch_stm (T.JUMP l) = [X.INSN (X.AL, X.MOVLBL (X.REG X.PC, l))]

     | munch_stm (T.JUMPIFN(e, l)) =
        let
          val (insns, pos, neg) = munch_cond e 
        in
     | munch_stm (T.JUMPIFN(e, l)) =
        let
          val (insns, pos, neg) = munch_cond e 
        in

-         insns @ [X.Jcc (neg, l)]
+         insns @ [X.INSN (neg, X.MOVLBL (X.REG X.PC, l))]

        end
        end

+    | munch_stm (T.EFFECT exp) = let val t = X.TEMP (Temp.new "throwaway") val i = munch_exp t exp in i end

 
   fun codegen nil = nil
     | codegen (stm::stms) = munch_stm stm @ codegen stms
 
   fun codegen nil = nil
     | codegen (stm::stms) = munch_stm stm @ codegen stms