diff options
Diffstat (limited to 'ghc/compiler/codeGen/CgCase.lhs')
| -rw-r--r-- | ghc/compiler/codeGen/CgCase.lhs | 70 |
1 files changed, 41 insertions, 29 deletions
diff --git a/ghc/compiler/codeGen/CgCase.lhs b/ghc/compiler/codeGen/CgCase.lhs index 99eb1ab89e..2182c17b8d 100644 --- a/ghc/compiler/codeGen/CgCase.lhs +++ b/ghc/compiler/codeGen/CgCase.lhs @@ -1,7 +1,7 @@ % % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % -% $Id: CgCase.lhs,v 1.25 1999/03/22 16:57:10 simonm Exp $ +% $Id: CgCase.lhs,v 1.26 1999/04/23 13:53:28 simonm Exp $ % %******************************************************** %* * @@ -27,12 +27,12 @@ import AbsCUtils ( mkAbstractCs, mkAbsCStmts, mkAlgAltsCSwitch, ) import CoreSyn ( isDeadBinder ) import CgUpdate ( reserveSeqFrame ) -import CgBindery ( getVolatileRegs, getArgAmodes, +import CgBindery ( getVolatileRegs, getArgAmodes, getArgAmode, bindNewToReg, bindNewToTemp, bindNewPrimToAmode, rebindToStack, getCAddrMode, getCAddrModeAndInfo, getCAddrModeIfVolatile, - buildContLivenessMask, nukeDeadBindings + buildContLivenessMask, nukeDeadBindings, ) import CgCon ( bindConArgs, bindUnboxedTupleComponents ) import CgHeapery ( altHeapCheck, yield ) @@ -62,8 +62,9 @@ import PrimRep ( getPrimRepSize, retPrimRepSize, PrimRep(..) import TyCon ( TyCon, isEnumerationTyCon, isUnboxedTupleTyCon, isNewTyCon, isAlgTyCon, isFunTyCon, isPrimTyCon, tyConDataCons, tyConFamilySize ) -import Type ( Type, typePrimRep, splitAlgTyConApp, splitTyConApp_maybe, - splitFunTys, applyTys ) +import Type ( Type, typePrimRep, splitAlgTyConApp, + splitTyConApp_maybe, + splitFunTys, applyTys ) import Unique ( Unique, Uniquable(..) ) import Maybes ( maybeToBool ) import Outputable @@ -116,14 +117,6 @@ Against: This never hurts us if there is only one alternative. - -*** NOT YET DONE *** The difficulty is that \tr{!B!}, \tr{!C!} need -to take account of what is live, and that includes all live volatile -variables, even if they also have stable analogues. Furthermore, the -stack pointers must be lined up properly so that GC sees tidy stacks. -If these things are done, then the heap checks can be done at \tr{!B!} and -\tr{!C!} without a full save-volatile-vars sequence. - \begin{code} cgCase :: StgExpr -> StgLiveVars @@ -137,7 +130,26 @@ cgCase :: StgExpr Several special cases for inline primitive operations. \begin{code} -cgCase (StgCon (PrimOp op) args res_ty) live_in_whole_case live_in_alts bndr srt alts +cgCase (StgCon (PrimOp TagToEnumOp) [arg] res_ty) + live_in_whole_case live_in_alts bndr srt alts + | isEnumerationTyCon tycon + = getArgAmode arg `thenFC` \amode -> + let + [res] = getPrimAppResultAmodes (getUnique bndr) alts + in + absC (CAssign res (CTableEntry + (CLbl (mkClosureTblLabel tycon) PtrRep) + amode PtrRep)) `thenC` + + -- Scrutinise the result + cgInlineAlts bndr alts + + | otherwise = panic "cgCase: tagToEnum# of non-enumerated type" + where + (Just (tycon,_)) = splitTyConApp_maybe res_ty + +cgCase (StgCon (PrimOp op) args res_ty) + live_in_whole_case live_in_alts bndr srt alts | not (primOpOutOfLine op) = -- Get amodes for the arguments and results @@ -338,22 +350,22 @@ getPrimAppResultAmodes -> [CAddrMode] \end{code} -\begin{code} --- If there's an StgBindDefault which does use the bound --- variable, then we can only handle it if the type involved is --- an enumeration type. That's important in the case --- of comparisions: --- --- case x ># y of --- r -> f r --- --- The only reason for the restriction to *enumeration* types is our --- inability to invent suitable temporaries to hold the results; --- Elaborating the CTemp addr mode to have a second uniq field --- (which would simply count from 1) would solve the problem. --- Anyway, cgInlineAlts is now capable of handling all cases; --- it's only this function which is being wimpish. +If there's an StgBindDefault which does use the bound +variable, then we can only handle it if the type involved is +an enumeration type. That's important in the case +of comparisions: + case x ># y of + r -> f r + +The only reason for the restriction to *enumeration* types is our +inability to invent suitable temporaries to hold the results; +Elaborating the CTemp addr mode to have a second uniq field +(which would simply count from 1) would solve the problem. +Anyway, cgInlineAlts is now capable of handling all cases; +it's only this function which is being wimpish. + +\begin{code} getPrimAppResultAmodes uniq (StgAlgAlts ty alts (StgBindDefault rhs)) | isEnumerationTyCon spec_tycon = [tag_amode] |