Add test for Hugs #37

testsuite/tests/ghc-regress/codeGen/should_run/all.T

@@ -58,3 +58,4 @@ test('cg057', compose( only_ways(['prof','profasm']),
 		       extra_run_opts('+RTS -xc') ),
 	 compile_and_run, [''])
 
+test('cg058', normal, compile_and_run, [''])

testsuite/tests/ghc-regress/codeGen/should_run/cg058.hs

+-- Not really a code-gen test, but this program gave
+-- incorrect results in Hugs (Husg Trac #37), so I 
+-- thought I'd add it to GHC's test suite.
+
+module Main where
+
+data MInt = Zero | Succ MInt | Pred MInt deriving Show
+
+tn :: Int -> MInt
+tn x | x<0 = Pred (tn (x+1))
+tn 0     =  Zero
+tn (n+1) = Succ (tn n)
+
+ti :: MInt -> Int
+ti Zero = 0
+ti (Succ x) = 1+(ti x)
+ti (Pred x) = (ti x) -1
+
+testi :: (MInt -> MInt -> MInt) -> (Int -> Int -> Int) -> Int -> Int -> Bool
+testi f g x y = (ti (f (tn x) (tn y))) /= (g x y)
+
+myMul x y = tn ((ti x) * (ti y))
+
+-- test should be empty!
+test = [ (x,y,ti (myMul (tn x) (tn y)),x * y)
+       | x<-[-100..100],
+         y<-([-100..(-1)]++[1..100]),
+	 testi myMul (*)  x y ]
+
+main = print test

testsuite/tests/ghc-regress/codeGen/should_run/cg058.stdout

+[]