diff options
Diffstat (limited to 'compiler/codeGen/StgCmmExpr.hs')
| -rw-r--r-- | compiler/codeGen/StgCmmExpr.hs | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/compiler/codeGen/StgCmmExpr.hs b/compiler/codeGen/StgCmmExpr.hs index 8282f1ec88..9e1d7fa37f 100644 --- a/compiler/codeGen/StgCmmExpr.hs +++ b/compiler/codeGen/StgCmmExpr.hs @@ -39,8 +39,8 @@ import ForeignCall import Id import PrimOp import TyCon -import Type -import RepType ( isVoidTy, countConRepArgs ) +import Type ( isUnliftedType ) +import RepType ( isVoidTy, countConRepArgs, primRepSlot ) import CostCentre ( CostCentreStack, currentCCS ) import Maybes import Util @@ -49,6 +49,7 @@ import Outputable import Control.Monad (unless,void) import Control.Arrow (first) +import Data.Function ( on ) import Prelude hiding ((<*>)) @@ -402,14 +403,23 @@ cgCase (StgApp v []) bndr alt_type@(PrimAlt _) alts = -- assignment suffices for unlifted types do { dflags <- getDynFlags ; unless reps_compatible $ - panic "cgCase: reps do not match, perhaps a dodgy unsafeCoerce?" + pprPanic "cgCase: reps do not match, perhaps a dodgy unsafeCoerce?" + (pp_bndr v $$ pp_bndr bndr) ; v_info <- getCgIdInfo v ; emitAssign (CmmLocal (idToReg dflags (NonVoid bndr))) (idInfoToAmode v_info) ; bindArgToReg (NonVoid bndr) ; cgAlts (NoGcInAlts,AssignedDirectly) (NonVoid bndr) alt_type alts } where - reps_compatible = idPrimRep v == idPrimRep bndr + reps_compatible = ((==) `on` (primRepSlot . idPrimRep)) v bndr + -- Must compare SlotTys, not proper PrimReps, because with unboxed sums, + -- the types of the binders are generated from slotPrimRep and might not + -- match. Test case: + -- swap :: (# Int | Int #) -> (# Int | Int #) + -- swap (# x | #) = (# | x #) + -- swap (# | y #) = (# y | #) + + pp_bndr id = ppr id <+> dcolon <+> ppr (idType id) <+> parens (ppr (idPrimRep id)) {- Note [Dodgy unsafeCoerce 2, #3132] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |