X-Git-Url: https://git.stderr.nl/gitweb?p=matthijs%2Fmaster-project%2Fc%CE%BBash.git;a=blobdiff_plain;f=clash%2FCLasH%2FNormalize.hs;h=11212f943df0678a4b9cef09fb52657ba06bc2dd;hp=a70829ade05370f51d66c9dbe0575e8e124ef97c;hb=ef7d876bddac1ebf8ae72dfac9aff33023650f53;hpb=c86f74b8af5fb3ca467c7a22fa2d14498b46fb1a

diff --git a/clash/CLasH/Normalize.hs b/clash/CLasH/Normalize.hs
index a70829a..11212f9 100644
--- a/clash/CLasH/Normalize.hs
+++ b/clash/CLasH/Normalize.hs
@@ -410,15 +410,14 @@ funextract c expr = return expr
 -- Make sure the scrutinee of a case expression is a local variable
 -- reference.
 scrutsimpl :: Transform
--- Don't touch scrutinees that are already simple
-scrutsimpl c expr@(Case (Var _) _ _ _) = return expr
--- Replace all other cases with a let that binds the scrutinee and a new
+-- Replace a case expression with a let that binds the scrutinee and a new
 -- simple scrutinee, but only when the scrutinee is representable (to prevent
 -- loops with inlinenonrep, though I don't think a non-representable scrutinee
--- will be supported anyway...) 
+-- will be supported anyway...) and is not a local variable already.
 scrutsimpl c expr@(Case scrut b ty alts) = do
   repr <- isRepr scrut
-  if repr
+  local_var <- Trans.lift $ is_local_var scrut
+  if repr && not local_var
     then do
       id <- Trans.lift $ mkBinderFor scrut "scrut"
       change $ Let (NonRec id scrut) (Case (Var id) b ty alts)
@@ -821,6 +820,10 @@ inlinenonrepresult context expr | not (is_applicable expr) && not (has_free_tyva
 -- Leave all other expressions unchanged
 inlinenonrepresult c expr = return expr
 
+----------------------------------------------------------------
+-- Type-class transformations
+----------------------------------------------------------------
+
 --------------------------------
 -- ClassOp resolution
 --------------------------------