import CmmExpr
import CoreSyn
import DataCon
+import ForeignCall
import Id
+import PrimOp
import TyCon
import CostCentre ( CostCentreStack, currentCCS )
import Maybes
cgExpr (StgApp fun args) = cgIdApp fun args
cgExpr (StgOpApp op args ty) = cgOpApp op args ty
cgExpr (StgConApp con args) = cgConApp con args
-
cgExpr (StgSCC cc expr) = do { emitSetCCC cc; cgExpr expr }
cgExpr (StgTick m n expr) = do { emit (mkTickBox m n); cgExpr expr }
-cgExpr (StgLit lit) = emitReturn [CmmLit (mkSimpleLit lit)]
+cgExpr (StgLit lit) = do cmm_lit <- cgLit lit
+ emitReturn [CmmLit cmm_lit]
-cgExpr (StgLet binds expr) = do { emit (mkComment $ mkFastString "calling cgBind"); cgBind binds; emit (mkComment $ mkFastString "calling cgExpr"); cgExpr expr }
+cgExpr (StgLet binds expr) = do { cgBind binds; cgExpr expr }
cgExpr (StgLetNoEscape _ _ binds expr) = do { cgLneBinds binds; cgExpr expr }
-cgExpr (StgCase expr _live_vars _save_vars bndr srt alt_type alts)
- = cgCase expr bndr srt alt_type alts
+cgExpr (StgCase expr _live_vars _save_vars bndr srt alt_type alts) =
+ cgCase expr bndr srt alt_type alts
cgExpr (StgLam {}) = panic "cgExpr: StgLam"
------------------------------------------------------------------------
{- Generating code for a let-no-escape binding, aka join point is very
-very similar to whatwe do for a case expression. The duality is
+very similar to what we do for a case expression. The duality is
between
let-no-escape x = b
in e
cgLneBinds (StgNonRec bndr rhs)
= do { local_cc <- saveCurrentCostCentre
-- See Note [Saving the current cost centre]
- ; (bndr,info) <- cgLetNoEscapeRhs local_cc bndr rhs
- ; addBindC bndr info }
+ ; info <- cgLetNoEscapeRhs local_cc bndr rhs
+ ; addBindC (cg_id info) info }
cgLneBinds (StgRec pairs)
= do { local_cc <- saveCurrentCostCentre
; addBindsC new_bindings }
+
-------------------------
-cgLetNoEscapeRhs
+cgLetNoEscapeRhs, cgLetNoEscapeRhsBody
:: Maybe LocalReg -- Saved cost centre
-> Id
-> StgRhs
- -> FCode (Id, CgIdInfo)
-
-cgLetNoEscapeRhs local_cc bndr (StgRhsClosure cc _bi _ _upd srt args body)
- = cgLetNoEscapeClosure bndr local_cc cc srt args body
-cgLetNoEscapeRhs local_cc bndr (StgRhsCon cc con args)
+ -> FCode CgIdInfo
+
+cgLetNoEscapeRhs local_cc bndr rhs =
+ do { (info, rhs_body) <- getCodeR $ cgLetNoEscapeRhsBody local_cc bndr rhs
+ ; let (bid, _) = expectJust "cgLetNoEscapeRhs" $ maybeLetNoEscape info
+ ; emit (outOfLine $ mkLabel bid emptyStackInfo <*> rhs_body)
+ ; return info
+ }
+
+cgLetNoEscapeRhsBody local_cc bndr (StgRhsClosure cc _bi _ _upd srt args body)
+ = cgLetNoEscapeClosure bndr local_cc cc srt (nonVoidIds args) body
+cgLetNoEscapeRhsBody local_cc bndr (StgRhsCon cc con args)
= cgLetNoEscapeClosure bndr local_cc cc NoSRT [] (StgConApp con args)
-- For a constructor RHS we want to generate a single chunk of
-- code which can be jumped to from many places, which will
-> Maybe LocalReg -- Slot for saved current cost centre
-> CostCentreStack -- XXX: *** NOT USED *** why not?
-> SRT
- -> [Id] -- Args (as in \ args -> body)
+ -> [NonVoid Id] -- Args (as in \ args -> body)
-> StgExpr -- Body (as in above)
- -> FCode (Id, CgIdInfo)
+ -> FCode CgIdInfo
cgLetNoEscapeClosure bndr cc_slot _unused_cc srt args body
= do { arg_regs <- forkProc $ do
-- Using altHeapCheck just reduces
-- instructions to save on stack
; return arg_regs }
- ; return (bndr, lneIdInfo bndr arg_regs) }
+ ; return $ lneIdInfo bndr arg_regs}
------------------------------------------------------------------------
-------------------------------------
cgCase :: StgExpr -> Id -> SRT -> AltType -> [StgAlt] -> FCode ()
+-- cgCase (OpApp ) bndr srt AlgAlt [(DataAlt flase, a2]
+ -- | isBoolTy (idType bndr)
+ -- , isDeadBndr bndr
+ -- =
+
cgCase scrut bndr srt alt_type alts
= do { up_hp_usg <- getVirtHp -- Upstream heap usage
; let ret_bndrs = chooseReturnBndrs bndr alt_type alts
; restoreCurrentCostCentre mb_cc
; bindArgsToRegs ret_bndrs
- ; cgAlts gc_plan bndr alt_type alts }
+ ; cgAlts gc_plan (NonVoid bndr) alt_type alts }
-----------------
maybeSaveCostCentre :: Bool -> FCode (Maybe LocalReg)
| otherwise = return Nothing
-
-----------------
isSimpleScrut :: StgExpr -> AltType -> Bool
--- Simple scrutinee, does not allocate
-isSimpleScrut (StgOpApp _ _ _) _ = True
-isSimpleScrut (StgLit _) _ = True
-isSimpleScrut (StgApp _ []) (PrimAlt _) = True
+-- Simple scrutinee, does not block or allocate; hence safe to amalgamate
+-- heap usage from alternatives into the stuff before the case
+-- NB: if you get this wrong, and claim that the expression doesn't allocate
+-- when it does, you'll deeply mess up allocation
+isSimpleScrut (StgOpApp op _ _) _ = isSimpleOp op
+isSimpleScrut (StgLit _) _ = True -- case 1# of { 0# -> ..; ... }
+isSimpleScrut (StgApp _ []) (PrimAlt _) = True -- case x# of { 0# -> ..; ... }
isSimpleScrut _ _ = False
+isSimpleOp :: StgOp -> Bool
+-- True iff the op cannot block or allocate
+isSimpleOp (StgFCallOp (CCall (CCallSpec _ _ safe)) _) = not (playSafe safe)
+isSimpleOp (StgFCallOp (DNCall _) _) = False -- Safe!
+isSimpleOp (StgPrimOp op) = not (primOpOutOfLine op)
+
-----------------
-chooseReturnBndrs :: Id -> AltType -> [StgAlt] -> [Id]
+chooseReturnBndrs :: Id -> AltType -> [StgAlt] -> [NonVoid Id]
-- These are the binders of a case that are assigned
-- by the evaluation of the scrutinee
-- Only non-void ones come back
= nonVoidIds ids -- 'bndr' is not assigned!
chooseReturnBndrs bndr (AlgAlt _) _alts
- = [bndr] -- Only 'bndr' is assigned
+ = nonVoidIds [bndr] -- Only 'bndr' is assigned
chooseReturnBndrs bndr PolyAlt _alts
- = [bndr] -- Only 'bndr' is assigned
+ = nonVoidIds [bndr] -- Only 'bndr' is assigned
chooseReturnBndrs _ _ _ = panic "chooseReturnBndrs"
-- UbxTupALt has only one alternative
-nonVoidIds :: [Id] -> [Id]
-nonVoidIds ids = [id | id <- ids, not (isVoidRep (idPrimRep id))]
-
-------------------------------------
-cgAlts :: GcPlan -> Id -> AltType -> [StgAlt] -> FCode ()
+cgAlts :: GcPlan -> NonVoid Id -> AltType -> [StgAlt] -> FCode ()
-- At this point the result of the case are in the binders
cgAlts gc_plan _bndr PolyAlt [(_, _, _, rhs)]
= maybeAltHeapCheck gc_plan (cgExpr rhs)
| (DataAlt con, cmm) <- tagged_cmms ]
-- Is the constructor tag in the node reg?
- ; if isSmallFamily fam_sz
+ ; if isSmallFamily fam_sz
then let -- Yes, bndr_reg has constr. tag in ls bits
tag_expr = cmmConstrTag1 (CmmReg bndr_reg)
branches' = [(tag+1,branch) | (tag,branch) <- branches]
-- UbxTupAlt and PolyAlt have only one alternative
-------------------
-cgAltRhss :: GcPlan -> Id -> [StgAlt] -> FCode [(AltCon, CmmAGraph)]
+cgAltRhss :: GcPlan -> NonVoid Id -> [StgAlt] -> FCode [(AltCon, CmmAGraph)]
cgAltRhss gc_plan bndr alts
= forkAlts (map cg_alt alts)
where
cg_alt (con, bndrs, _uses, rhs)
= getCodeR $
maybeAltHeapCheck gc_plan $
- do { bindConArgs con base_reg bndrs
+ do { pprTrace "binding args for" (ppr bndr <+> ppr con) $ bindConArgs con base_reg bndrs
; cgExpr rhs
; return con }
cgConApp :: DataCon -> [StgArg] -> FCode ()
cgConApp con stg_args
+ | isUnboxedTupleCon con -- Unboxed tuple: assign and return
+ = do { arg_exprs <- getNonVoidArgAmodes stg_args
+ ; tickyUnboxedTupleReturn (length arg_exprs)
+ ; emitReturn arg_exprs }
+
+ | otherwise -- Boxed constructors; allocate and return
= ASSERT( stg_args `lengthIs` dataConRepArity con )
- do { idinfo <- buildDynCon (dataConWorkId con) currentCCS con stg_args
+ do { (idinfo, init) <- buildDynCon (dataConWorkId con) currentCCS con stg_args
-- The first "con" says that the name bound to this closure is
-- is "con", which is a bit of a fudge, but it only affects profiling
+ ; emit init
; emitReturn [idInfoToAmode idinfo] }
+
cgIdApp :: Id -> [StgArg] -> FCode ()
+cgIdApp fun_id [] | isVoidId fun_id = emitReturn []
cgIdApp fun_id args
= do { fun_info <- getCgIdInfo fun_id
- ; case maybeLetNoEscape fun_info of
- Just (blk_id, lne_regs) -> cgLneJump blk_id lne_regs args
- Nothing -> cgTailCall fun_id fun_info args }
+ ; case maybeLetNoEscape fun_info of
+ Just (blk_id, lne_regs) -> cgLneJump blk_id lne_regs args
+ Nothing -> cgTailCall fun_id fun_info args }
cgLneJump :: BlockId -> [LocalReg] -> [StgArg] -> FCode ()
cgLneJump blk_id lne_regs args -- Join point; discard sequel
cgTailCall fun_id fun_info args
= case (getCallMethod fun_name (idCafInfo fun_id) lf_info (length args)) of
- -- A value in WHNF, so we can just return it.
+ -- A value in WHNF, so we can just return it.
ReturnIt -> emitReturn [fun] -- ToDo: does ReturnIt guarantee tagged?
EnterIt -> ASSERT( null args ) -- Discarding arguments
- do { [ret,call] <- forkAlts [
+ do { let fun' = CmmLoad fun (cmmExprType fun)
+ ; [ret,call] <- forkAlts [
getCode $ emitReturn [fun], -- Is tagged; no need to untag
- getCode $ emitCall (entryCode fun) [fun]] -- Not tagged
+ getCode $ do emit (mkAssign nodeReg fun)
+ emitCall Native (entryCode fun') []] -- Not tagged
; emit (mkCmmIfThenElse (cmmIsTagged fun) ret call) }
SlowCall -> do -- A slow function call via the RTS apply routines
{ tickySlowCall lf_info args
+ ; emit $ mkComment $ mkFastString "slowCall"
; slowCall fun args }
-- A direct function call (possibly with some left-over arguments)
DirectEntry lbl arity -> do
{ tickyDirectCall arity args
; if node_points then
- do call <- getCode $ directCall lbl arity args
- emit (mkAssign nodeReg fun <*> call)
+ do emit $ mkComment $ mkFastString "directEntry"
+ emit (mkAssign nodeReg fun)
+ directCall lbl arity args
-- directCall lbl (arity+1) (StgVarArg fun_id : args))
-- >>= (emit . (mkComment (mkFastString "DirectEntry") <*>))
- else directCall lbl arity args }
+ else do emit $ mkComment $ mkFastString "directEntry else"
+ directCall lbl arity args }
JumpToIt {} -> panic "cgTailCall" -- ???
where
- fun_name = idName fun_id
- fun = idInfoToAmode fun_info
- lf_info = cgIdInfoLF fun_info
+ fun_name = idName fun_id
+ fun = idInfoToAmode fun_info
+ lf_info = cgIdInfoLF fun_info
node_points = nodeMustPointToIt lf_info
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