Improve hashing of expressions for CSE (reduces warnings about extendCSEnv)

[ghc-hetmet.git] / compiler / coreSyn / CoreUtils.lhs

diff --git a/compiler/coreSyn/CoreUtils.lhs b/compiler/coreSyn/CoreUtils.lhs
index a43be02..d4d58df 100644 (file)
--- a/compiler/coreSyn/CoreUtils.lhs
+++ b/compiler/coreSyn/CoreUtils.lhs
@@ -1386,10 +1386,10 @@ fast_hash_expr env other        = 1
 
 fast_hash_type :: HashEnv -> Type -> Word32
 fast_hash_type env ty 
-  | Just tv <- getTyVar_maybe ty          = hashVar env tv
-  | Just (tc,_) <- splitTyConApp_maybe ty
-                              = fromIntegral (hashName (tyConName tc))
-  | otherwise                            = 1
+  | Just tv <- getTyVar_maybe ty            = hashVar env tv
+  | Just (tc,tys) <- splitTyConApp_maybe ty = let hash_tc = fromIntegral (hashName (tyConName tc))
+                                             in foldr (\t n -> fast_hash_type env t + n) hash_tc tys
+  | otherwise                              = 1
 
 extend_env :: HashEnv -> Var -> (Int, VarEnv Int)
 extend_env (n,env) b = (n+1, extendVarEnv env b n)