Add string pasting support to the gramamr.

[snipe.git] / codegen / codegen.sml

diff --git a/codegen/codegen.sml b/codegen/codegen.sml
index 9b99ef723ec9f60bc30aeb3279dd3655775373a8..a407a2014ec562685de39437787879d1f427c35b 100644 (file)
--- a/codegen/codegen.sml
+++ b/codegen/codegen.sml
@@ -1,4 +1,4 @@
-(* L2 Compiler
+(* L3 Compiler

  * Assembly code generator for fake x86 assembly
  * Author: Joshua Wise <jwise@andrew.cmu.edu>
  * Author: Chris Lu <czl@andrew.cmu.edu>
  * Assembly code generator for fake x86 assembly
  * Author: Joshua Wise <jwise@andrew.cmu.edu>
  * Author: Chris Lu <czl@andrew.cmu.edu>


@@ -6,181 +6,332 @@
 
 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
+  structure TU = TreeUtils
+  structure X = Blarg
+  structure Tm = Temp
+
+  (* hasfixed : T.exp -> bool
+   * true iff the given expression has an hasfixed.
+   *)
+  fun hasfixed (T.CALL _) = true
+    | 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
+
+  (* 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
+      i1 @ i2 @ [X.INSN (X.AL, oper (d, t))]
+    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.MOVL(d, X.CONST n)]
-    | munch_exp d (T.TEMP(t)) = [X.MOVL(d, X.TEMP t)]
-    | munch_exp d (T.BINOP(T.ADD, e1, T.CONST n)) = (munch_exp d e1) @ [X.ADDL(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.ADD, T.CONST n, e1)) = (munch_exp d e1) @ [X.ADDL(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.ADD, e1, e2)) =
+  and munch_exp d (T.CONST n) = [X.INSN (X.AL, X.MOVLIT(d, Word.fromLarge (Word32.toLarge n)))]
+    | munch_exp d (T.STRING s) = [X.INSN (X.AL, X.MOVSTR(d, s))]
+    | 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
         let

-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @ [X.ADDL(d, X.TEMP 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(n))) = (munch_exp d e1) @ [X.SUBL(d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.SUB, e1, e2)) =
-        let val
-          t1 = Temp.new ()
+          val nargs = length l
+          val nstack = if (nargs <= 4)
+                       then 0
+                       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 = 
+              let
+                val t = Temp.new "argdest"
+                val t2 = Temp.new "argptr"
+              in
+                (X.TEMP t, (* Dude, I *love* this shit. *)
+                 [ X.INSN (X.AL, X.MOVLIT (X.TEMP t2, Word.fromInt (0x10000 - (n - 4 + 1)))),
+                   X.INSN (X.AL, X.ADD (X.TEMP t2, X.REG X.SP)),
+                   X.INSN (X.AL, X.STO (X.TEMP t2, X.TEMP t)) ] )
+              end
+
+          val dests = List.tabulate (nargs, fn x => argdest (x+1))
+          val hf = List.map hasfixed l
+          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)
+          )
+          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)
+          )
+          val temps = List.map (fn _ => Temp.new ("arg")) l_hf
+          val argevals_hf = List.map
+            (fn (t,exp) => munch_exp (X.TEMP t) exp)
+            (ListPair.zip (temps, l_hf))
+          val argpushes = List.map
+            (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_nohf, l_nohf))
+          val shittodo = List.concat (List.map (fn (_, shit) => shit) (d_hf @ d_nohf))
+          
+          val t_stackb = Temp.new ("stackb")
+          val t_target = Temp.new ("target")

         in
         in

-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @ [X.SUBL(d, X.TEMP t1)]
+          List.concat argevals_hf @ 
+          List.concat argpushes @
+          List.concat argevals_nohf @
+          shittodo @
+          (if stackb > 0
+           then [ 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))]
+           else [ X.INSN (X.AL, X.MOVSYM (X.TEMP t_target, name)),
+                  X.INSN (X.AL, X.CALL (X.REG X.SP, X.TEMP t_target, nargs)),
+                  X.INSN (X.AL, X.MOV (d, X.REG X.R0))]
+          )

         end
         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 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)) =
+    (*| 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.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
         let

-          val t1 = Temp.new ()
+          val (insn1, pos1, neg1) = munch_cond e1
+          val (insn2, pos2, neg2) = munch_cond e2
+          val l = Label.new ()

         in
         in

-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @ [X.IMUL(d, X.TEMP 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
         end

-    | munch_exp d (T.BINOP(T.DIV, e1, e2)) =
+    | munch_exp d (a as T.BINOP(T.LOGOR, e1, e2)) =

         let
         let

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

         in
         in

-          (munch_exp (X.TEMP t1) e1) @ (munch_exp d e2) @
-          [X.MOVL (X.REG X.EAX, X.TEMP t1), X.CLTD, X.IDIVL d, X.MOVL (d, X.REG X.EAX)]
+          (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 (T.BINOP(T.MOD, e1, e2)) =
+    | 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 t1 = Temp.new ()
+          val t = Temp.new "-val"
+          val i = munch_exp (X.TEMP t) e1

         in
         in

-          (munch_exp (X.TEMP t1) e1) @ (munch_exp d e2) @
-          [X.MOVL (X.REG X.EAX, X.TEMP t1), X.CLTD, X.IDIVL d, X.MOVL (d, X.REG X.EDX)]
+          (i) @
+          [X.INSN (X.AL, X.MOVLIT (d, 0w0)),
+           X.INSN (X.AL, X.SUB (d, X.TEMP t))]

         end
         end

-    | munch_exp d (T.BINOP(T.LSH, e1, T.CONST n)) = (munch_exp d e1) @ [X.SALL (d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.LSH, e1, e2)) =
+    | 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
         let

-          val t1 = Temp.new()
+          val (insns, pos, neg) = munch_cond e

         in
         in

-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.MOVL (X.REG X.ECX, X.TEMP t1), X.SALL (d, X.REG X.ECX)]
+          insns @
+          [X.INSN (X.AL, X.MOVLIT (d, 0w0)),
+           X.INSN (neg, X.MOVLIT (d, 0w1))]

         end
         end

-    | munch_exp d (T.BINOP(T.RSH, e1, T.CONST n)) = (munch_exp d e1) @ [X.SARL (d, X.CONST n)]
-    | munch_exp d (T.BINOP(T.RSH, e1, e2)) =
+    | munch_exp d (T.MEMORY (e1)) =

         let
         let

-          val t1 = Temp.new()
+          val a = X.TEMP (Temp.new "addr")
+          val i = munch_exp a e1

         in
         in

-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.MOVL (X.REG X.ECX, X.TEMP t1), X.SARL (d, X.REG X.ECX)]
+          i @
+          [X.INSN (X.AL, X.LDR (d, a))]

         end
         end

-    | munch_exp d (T.BINOP(T.LOGOR, e1, e2)) =
+    
+    | munch_exp d (T.ALLOC(exp)) =

         let
         let

+          val t1 = Temp.new "alloc"

           val l1 = Label.new()
           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 d e1) @ [X.CMPL (d, X.CONST(0w0)), X.JNE l1] @ (munch_exp d e2) @ [X.CMPL (d, X.CONST(0w0)), X.LABEL l1, X.SETNE d, X.MOVZBL(d,d)]
+          einsn @ insns 

         end
         end

-    | munch_exp d (T.BINOP(T.LOGAND, 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 (insns, pos, neg) = munch_cond c

           val l1 = Label.new()
           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 d e1) @ [X.CMPL (d, X.CONST(0w0)), X.JE l1] @ (munch_exp d e2) @ [X.CMPL (d, X.CONST(0w0)), X.LABEL l1, X.SETNE d, X.MOVZBL(d,d)]
+          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_exp d (T.BINOP(T.BITAND, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @ [X.ANDL(d, X.TEMP t1)]
-        end
-    | munch_exp d (T.BINOP(T.BITOR, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @ [X.ORL(d, X.TEMP t1)]
-        end
-    | munch_exp d (T.BINOP(T.BITXOR, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @ [X.XORL(d, X.TEMP t1)]
-        end
-    | munch_exp d (T.BINOP(T.NEQ, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.CMPL(d, X.TEMP t1), X.SETNE(d), X.MOVZBL(d, d)]
-        end
-    | munch_exp d (T.BINOP(T.EQ, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.CMPL(d, X.TEMP t1), X.SETE(d), X.MOVZBL(d, d)]
-        end
-    | munch_exp d (T.BINOP(T.LE, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.CMPL(d, X.TEMP t1), X.SETLE(d), X.MOVZBL(d, d)]
-        end
-    | munch_exp d (T.BINOP(T.LT, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.CMPL(d, X.TEMP t1), X.SETL(d), X.MOVZBL(d, d)]
-        end
-    | munch_exp d (T.BINOP(T.GE, e1, e2)) =
-        let
-          val t1 = Temp.new ()
-        in
-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.CMPL(d, X.TEMP t1), X.SETGE(d), X.MOVZBL(d, d)]
-        end
-    | munch_exp d (T.BINOP(T.GT, 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 t1 = Temp.new ()
+          val (insns, pos, neg) = munch_cond e

         in
         in

-          (munch_exp d e1) @ (munch_exp (X.TEMP t1) e2) @
-          [X.CMPL(d, X.TEMP t1), X.SETG(d), X.MOVZBL(d, d)]
+          (insns, neg, pos)

         end
         end

-    | munch_exp d (T.UNOP(T.NEG, e1)) = (munch_exp d e1) @ [X.NEG d]
-    | munch_exp d (T.UNOP(T.BITNOT, e1)) = (munch_exp d e1) @ [X.NOTL d]
-    | munch_exp d (T.UNOP(T.BANG, e1)) = (munch_exp d e1) @
-                                         [X.TEST(d,d), X.SETE(d), X.MOVZBL(d, d)]
+    | 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"))
+        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
+        i @
+        [X.INSN (X.AL, X.STO (t, oper))]
+      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(t1), e2)) =
+  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 (Word32.toLarge 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 (a, e2)) =

         let
         let

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

         in
         in

-          munch_exp (X.TEMP t) e
-          @ [X.MOVL(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
     | munch_stm (T.JUMPIFN(e, l)) =
        let

-         val t = Temp.new ()
+         val (insns, pos, neg) = munch_cond e 

        in
        in

-         munch_exp (X.TEMP t) e
-         @ [X.TEST(X.TEMP t, X.TEMP t), X.JE 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