[project @ 1999-04-23 13:53:28 by simonm]

[ghc-hetmet.git] / ghc / compiler / codeGen / CgExpr.lhs

diff --git a/ghc/compiler/codeGen/CgExpr.lhs b/ghc/compiler/codeGen/CgExpr.lhs
index 6e02c25..7b11429 100644 (file)
--- a/ghc/compiler/codeGen/CgExpr.lhs
+++ b/ghc/compiler/codeGen/CgExpr.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgExpr.lhs,v 1.22 1999/03/25 13:13:51 simonm Exp $
+% $Id: CgExpr.lhs,v 1.23 1999/04/23 13:53:29 simonm Exp $
 %
 %********************************************************
 %*                                                     *
@@ -22,7 +22,7 @@ import AbsCUtils      ( mkAbstractCs )
 import CLabel          ( mkClosureTblLabel )
 
 import SMRep           ( fixedHdrSize )
-import CgBindery       ( getArgAmodes, CgIdInfo, nukeDeadBindings )
+import CgBindery       ( getArgAmodes, getArgAmode, CgIdInfo, nukeDeadBindings)
 import CgCase          ( cgCase, saveVolatileVarsAndRegs, 
                          restoreCurrentCostCentre, freeCostCentreSlot,
                          splitTyConAppThroughNewTypes )
@@ -48,7 +48,7 @@ import PrimOp         ( primOpOutOfLine,
 import PrimRep         ( getPrimRepSize, PrimRep(..), isFollowableRep )
 import TyCon           ( maybeTyConSingleCon,
                          isUnboxedTupleTyCon, isEnumerationTyCon )
-import Type            ( Type, typePrimRep )
+import Type            ( Type, typePrimRep, splitTyConApp_maybe )
 import Maybes          ( assocMaybe, maybeToBool )
 import Unique          ( mkBuiltinUnique )
 import BasicTypes      ( TopLevelFlag(..), RecFlag(..) )
@@ -116,12 +116,30 @@ NOTE about _ccall_GC_:
 A _ccall_GC_ is treated as an out-of-line primop for the case
 expression code, because we want a proper stack frame on the stack
 when we perform it.  When we get here, however, we need to actually
-perform the call, so we treat it an an inline primop.
+perform the call, so we treat it as an inline primop.
 
 \begin{code}
 cgExpr (StgCon (PrimOp op@(CCallOp _ _ may_gc@True _)) args res_ty)
   = primRetUnboxedTuple op args res_ty
 
+-- tagToEnum# is special: we need to pull the constructor out of the table,
+-- and perform an appropriate return.
+
+cgExpr (StgCon (PrimOp TagToEnumOp) [arg] res_ty) 
+  | isEnumerationTyCon tycon =
+       getArgAmode arg `thenFC` \amode ->
+       performReturn (CAssign (CReg node) 
+                       (CTableEntry 
+                         (CLbl (mkClosureTblLabel tycon) PtrRep)
+                         amode PtrRep))
+                 (\ sequel -> mkDynamicAlgReturnCode tycon amode sequel)
+
+  | otherwise = panic "cgExpr: tagToEnum# of non-enumerated type"
+
+   where
+       (Just (tycon,_)) = splitTyConApp_maybe res_ty
+
+
 cgExpr x@(StgCon (PrimOp op) args res_ty)
   | primOpOutOfLine op = tailCallPrimOp op args
   | otherwise
@@ -144,7 +162,6 @@ cgExpr x@(StgCon (PrimOp op) args res_ty)
        ReturnsAlg tycon
            | isUnboxedTupleTyCon tycon -> primRetUnboxedTuple op args res_ty
 
-
            | isEnumerationTyCon  tycon ->
                performReturn
                     (COpStmt [dyn_tag] op arg_amodes [{-no vol_regs-}])