From ddb69212f03a82e980144594d809a072b50e7f19 Mon Sep 17 00:00:00 2001
From: Rose Hogenson <rhogenson@posteo.net>
Date: Sat, 11 Feb 2023 09:40:25 -0800
Subject: Finish the compiler.

Just joking. But we did manage to compile a program from SML
to bytecode.
---
 linker.sml | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

(limited to 'linker.sml')

diff --git a/linker.sml b/linker.sml
index b52e84b..874e145 100644
--- a/linker.sml
+++ b/linker.sml
@@ -18,23 +18,33 @@ struct
     BinIO.output1 (w, Word8.fromInt (Word.toInt (Word.andb (n, Word.fromInt 0xff))))
 
   fun writeInt w i =
-    let
-      val n = Word.fromInt i
-      fun go b =
-        if b < 8
-        then
-          (lowByte w (Word.>> (n, Word.fromInt (8 * b))) ;
-           go (b + 1))
-        else ()
+    let val n = Word.fromInt i
     in
-      go 0
+      (lowByte w (Word.orb (Word.<< (n, Word.fromInt 1), Word.fromInt 0x1)) ;
+       lowByte w (Word.>> (n, Word.fromInt 7)) ;
+       lowByte w (Word.>> (n, Word.fromInt 15)) ;
+       lowByte w (Word.>> (n, Word.fromInt 23)) ;
+       lowByte w (Word.>> (n, Word.fromInt 31)) ;
+       lowByte w (Word.>> (n, Word.fromInt 39)) ;
+       lowByte w (Word.>> (n, Word.fromInt 47)) ;
+       lowByte w (Word.>> (n, Word.fromInt 55)))
     end
 
+  fun writeVar w v =
+    if v > 7
+    then raise Fail ("var out of range: " ^ Int.toString v)
+    else lowByte w (Word.fromInt v)
+
+  fun writeOffset w i =
+    if ~128 > i orelse i > 127
+    then raise Fail ("offset out of range: " ^ Int.toString i)
+    else lowByte w 
+
   structure IntMap = Map(type k = int val cmp = Int.compare);
 
   fun encode (m : int IntMap.map) (w : BinIO.outstream) (oper : Syntax.opcode) : unit =
     let
-      fun writeValue w (Syntax.VVar v) = writeInt w v
+      fun writeValue w (Syntax.VVar v) = writeVar w v
         | writeValue w (Syntax.VLabel l) = writeInt w (getOpt (IntMap.lookup l m, 0))
         | writeValue w (Syntax.VInt i) = writeInt w i
         | writeValue w (Syntax.VString _) = raise Fail "I don't support strings yet"
@@ -42,23 +52,23 @@ struct
       case oper of
         Syntax.OAlloc (r, v) =>
           (makeOpcode w 1 (isConst v) false ;
-           writeInt w r ;
+           writeVar w r ;
            writeValue w v)
       | Syntax.OCall =>
           makeOpcode w 2 false false
       | Syntax.OPoke (off, p, v) =>
           (makeOpcode w 3 (isConst v) false ;
            writeInt w off ;
-           writeInt w p ;
+           writeVar w p ;
            writeValue w v)
       | Syntax.OPeek (r, off, v) =>
           (makeOpcode w 4 (isConst v) false ;
-           writeInt w r ;
+           writeVar w r ;
            writeInt w off ;
            writeValue w v)
       | Syntax.OShuf (r, v) =>
           (makeOpcode w 5 (isConst v) false ;
-           writeInt w r ;
+           writeVar w r ;
            writeValue w v)
       | Syntax.OExit v =>
           (makeOpcode w 6 (isConst v) false ;
-- 
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