Slightly better

1 files changed, 14 insertions, 8 deletions

diff --git a/src/Micro/Asm/Sdcc.hs b/src/Micro/Asm/Sdcc.hs
index a3f83ed..af4e7d7 100644
--- a/src/Micro/Asm/Sdcc.hs
+++ b/src/Micro/Asm/Sdcc.hs
@@ -62,6 +62,17 @@ mul8 a b p = do
          toLabel loop0 True
        ]
 
+mul :: A.Expr -> A.Expr -> SourcePos -> [String]
+mul a b@(A.Num v _) p
+  | v == 2 = oCode (emit a) ++ ["\tsla a"]
+  | v == 4 = oCode (emit a) ++ replicate 2 "\tsla a"
+  | v == 8 = oCode (emit a) ++ replicate 3 "\tsla a"
+  | v == 16 = oCode (emit a) ++ replicate 4 "\tsla a"
+  | v == 32 = oCode (emit a) ++ replicate 5 "\tsla a"
+  | v < 6 = oCode (emit a) ++ ["\tld c, a"] ++ replicate (fromInteger v - 1) "\tadd c"
+  | otherwise = mul8 a b p
+mul _ _ _ = [";; unimplemented"]
+
 data Output = Output
   { oPre :: [String],
     oInit :: [String],
@@ -104,14 +115,9 @@ emit x =
       o {oCode = ["\txor a"]}
     (A.BinOp A.Mul _ (A.Num 1 _) b) -> o {oCode = oCode (emit b)}
     (A.BinOp A.Mul _ a (A.Num 1 _)) -> o {oCode = oCode (emit a)}
-    (A.BinOp A.Mul _ a (A.Num 2 _)) ->
-      o {oCode = oCode (emit a) ++ ["\tsla a"]}
-    (A.BinOp A.Mul _ (A.Num 2 _) b) ->
-      o {oCode = oCode (emit b) ++ ["\tsla a"]}
-    (A.BinOp A.Mul _ a (A.Num v _)) ->
-      o {oCode = oCode (emit a) ++ ["\tld c, a"] ++ replicate (fromInteger v - 1) "\tadd c"}
-    (A.BinOp A.Mul p a b) -> do
-      o {oCode = mul8 a b p}
+    (A.BinOp A.Mul pos a b@(A.Num _ _)) -> o {oCode = mul a b pos}
+    (A.BinOp A.Mul pos a@(A.Num _ _) b) -> o {oCode = mul b a pos}
+    (A.BinOp A.Mul p a b) -> o {oCode = mul8 a b p}
     (A.BinOp A.Assign _ (A.Variable id _) b) ->
       o {oCode = oCode (emit b) ++ ["\tld (" ++ toIdent id ++ "), a"]}
     _ -> o {oCode = [";; unimplemented " ++ show x]}