diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/simplCore/SimplUtils.hs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/compiler/simplCore/SimplUtils.hs b/compiler/simplCore/SimplUtils.hs index 47c5be6d8e..3b48924ed1 100644 --- a/compiler/simplCore/SimplUtils.hs +++ b/compiler/simplCore/SimplUtils.hs @@ -64,6 +64,7 @@ import PrelRules import Literal import Control.Monad ( when ) +import Data.List ( sortBy ) {- ************************************************************************ @@ -1926,7 +1927,7 @@ mkCase1 dflags scrut bndr alts_ty alts = mkCase2 dflags scrut bndr alts_ty alts mkCase2 dflags scrut bndr alts_ty alts | gopt Opt_CaseFolding dflags , Just (scrut',f) <- caseRules dflags scrut - = mkCase3 dflags scrut' bndr alts_ty (map (mapAlt f) alts) + = mkCase3 dflags scrut' bndr alts_ty (new_alts f) | otherwise = mkCase3 dflags scrut bndr alts_ty alts where @@ -1946,6 +1947,9 @@ mkCase2 dflags scrut bndr alts_ty alts | isDeadBinder bndr = rhs | otherwise = Let (NonRec bndr l) rhs + -- We need to re-sort the alternatives to preserve the #case_invariants# + new_alts f = sortBy cmpAlt (map (mapAlt f) alts) + mapAlt f alt@(c,bs,e) = case c of DEFAULT -> (c, bs, wrap_rhs scrut e) LitAlt l |