Add a test for 2-word-multiply

testsuite/tests/numeric/should_run/all.T

@@ -55,4 +55,5 @@ test('4381', normal, compile_and_run, [''])
 test('4383', normal, compile_and_run, [''])
 
 test('add2', normal, compile_and_run, [''])
+test('mul2', normal, compile_and_run, [''])
 

testsuite/tests/numeric/should_run/mul2.hs

+
+{-# LANGUAGE MagicHash, UnboxedTuples #-}
+
+import GHC.Prim
+import GHC.Word
+import Data.Bits
+
+main :: IO ()
+main = do f 5 6
+          f 0xFE36FB18 49
+          f 0xFE36FB18 0xFB29FC6A
+
+f :: Word -> Word -> IO ()
+f wx@(W# x) wy@(W# y)
+    = do putStrLn "-----"
+         putStrLn ("Doing " ++ show wx ++ " * " ++ show wy)
+         case x `timesWord2#` y of
+             (# h, l #) ->
+                 do let wh = W# h
+                        wl = W# l
+                        r = shiftL (fromIntegral wh) (bitSize wh)
+                          + fromIntegral wl
+                    putStrLn ("High: " ++ show wh)
+                    putStrLn ("Low: " ++ show wl)
+                    putStrLn ("Result: " ++ show (r :: Integer))
+

testsuite/tests/numeric/should_run/mul2.stdout

+-----
+Doing 5 * 6
+High: 0
+Low: 30
+Result: 30
+-----
+Doing 4265016088 * 49
+High: 0
+Low: 208985788312
+Result: 208985788312
+-----
+Doing 4265016088 * 4213832810
+High: 0
+Low: 17972064726792247280
+Result: 17972064726792247280