[project @ 2001-10-17 16:08:35 by simonpj]

[ghc-hetmet.git] / ghc / compiler / simplCore / Simplify.lhs

diff --git a/ghc/compiler/simplCore/Simplify.lhs b/ghc/compiler/simplCore/Simplify.lhs
index 2edb45b..ee35251 100644 (file)
--- a/ghc/compiler/simplCore/Simplify.lhs
+++ b/ghc/compiler/simplCore/Simplify.lhs
@@ -565,10 +565,7 @@ completeLazyBind env top_lvl old_bndr new_bndr new_rhs
                   | otherwise    = new_bndr_info `setUnfoldingInfo` unfolding
        unfolding = mkUnfolding (isTopLevel top_lvl) new_rhs
 
-               -- Don't fiddle with the IdInfo of a constructor
-               -- wrapper or other GlobalId.
-       final_id | isLocalId new_bndr = new_bndr `setIdInfo` info_w_unf
-                | otherwise          = new_bndr
+       final_id = new_bndr `setIdInfo` info_w_unf
     in
                -- These seqs forces the Id, and hence its IdInfo,
                -- and hence any inner substitutions
@@ -1241,6 +1238,10 @@ rebuildCase env scrut case_bndr alts cont
                        []    -> alts
                        other -> [alt | alt@(con,_,_) <- alts, 
                                        not (con `elem` impossible_cons)]
+
+       -- handled_cons are handled either by the context, 
+       -- or by an alternative in this case
+       handled_cons = impossible_cons ++ [con | (con,_,_) <- better_alts]
     in
 
        -- Deal with the case binder, and prepare the continuation;
@@ -1252,11 +1253,11 @@ rebuildCase env scrut case_bndr alts cont
     simplCaseBinder env scrut case_bndr                `thenSmpl` \ (alt_env, case_bndr', zap_occ_info) ->
 
        -- Deal with the case alternatives
-    simplAlts alt_env zap_occ_info impossible_cons
+    simplAlts alt_env zap_occ_info handled_cons
              case_bndr' better_alts cont'              `thenSmpl` \ alts' ->
 
        -- Put the case back together
-    mkCase scrut case_bndr' alts'                      `thenSmpl` \ case_expr ->
+    mkCase scrut handled_cons case_bndr' alts'         `thenSmpl` \ case_expr ->
 
        -- Notice that rebuildDone returns the in-scope set from env, not alt_env
        -- The case binder *not* scope over the whole returned case-expression
@@ -1361,20 +1362,16 @@ simplCaseBinder env other_scrut case_bndr
 simplAlts :: SimplEnv 
          -> (InId -> InId)             -- Occ-info zapper
          -> [AltCon]                   -- Alternatives the scrutinee can't be
+                                       -- in the default case
          -> OutId                      -- Case binder
          -> [InAlt] -> SimplCont
          -> SimplM [OutAlt]            -- Includes the continuation
 
-simplAlts env zap_occ_info impossible_cons case_bndr' alts cont'
+simplAlts env zap_occ_info handled_cons case_bndr' alts cont'
   = mapSmpl simpl_alt alts
   where
     inst_tys' = tyConAppArgs (idType case_bndr')
 
-       -- handled_cons is all the constructors that are dealt
-       -- with, either by being impossible, or by there being an alternative
-    (con_alts,_) = findDefault alts
-    handled_cons = impossible_cons ++ [con | (con,_,_) <- con_alts]
-
     simpl_alt (DEFAULT, _, rhs)
        = let
                -- In the default case we record the constructors that the