Unboxed arrays in FSu

20% faster than before on suvh.txt

1 files changed, 6 insertions, 8 deletions

diff --git a/hsolve/FSu.hs b/hsolve/FSu.hs
index 1bd250a..1d0eea3 100644
--- a/hsolve/FSu.hs
+++ b/hsolve/FSu.hs
@@ -10,7 +10,7 @@ import Data.STRef
 type Value = Int  -- Sudoku value
 type Index = Int  -- Sudoku index
 
-type Arr s a = STArray s Int a
+type Arr s a = STUArray s Int a
 
 data State s = State { stateMark :: Arr s Bool, stateResults :: STRef s [[Maybe Value]] }
 
@@ -54,7 +54,7 @@ tryAll arr !i (v:vs) st = do
 -- assumes the considered position is empty
 getPoss :: forall s. Arr s Value -> Index -> State s -> ST s [Value]
 getPoss arr i st = do
-    fillArray mark 0 8 True
+    fillArrayBool mark 0 8 True
     goRow (rowOf i) 0
     goCol (colOf i) 0
     goBlock (blockOrigin (blockOf i)) 0
@@ -107,7 +107,7 @@ isValidBlock arr b st = indexSetNoDups arr [blockOrigin b + 9 * y + x| y <- [0..
 
 indexSetNoDups :: forall s. Arr s Value -> [Index] -> State s -> ST s Bool
 indexSetNoDups arr set st = do
-    fillArray mark 0 8 False
+    fillArrayBool mark 0 8 False
     applyInMark set
   where
     mark = stateMark st
@@ -124,11 +124,9 @@ indexSetNoDups arr set st = do
                 then return False
                 else writeArray mark v True >> applyInMark is
 
-fillArray :: Arr s a -> Int -> Int -> a -> ST s ()
-fillArray arr !i1 !i2 v
-    | i1 <= i2 = do
-        writeArray arr i1 v
-        fillArray arr (i1 + 1) i2 v
+fillArrayBool :: Arr s Bool -> Int -> Int -> Bool -> ST s ()
+fillArrayBool arr !i1 !i2 v
+    | i1 <= i2 = unsafeWrite arr i1 v >> fillArrayBool arr (i1 + 1) i2 v
     | otherwise = return ()
 
 rowOf :: Index -> Index