)
where
-import Cmm
+import BlockId
import CmmExpr
import CmmTx
import DFMonad
-import Maybes
+import Monad
import PprCmm()
import PprCmmZ()
-import UniqSet
+import ZipCfg
import ZipDataflow
import ZipCfgCmmRep
+import Maybes
+import UniqSet
+
-----------------------------------------------------------------------------
-- Calculating what variables are live on entry to a basic block
-----------------------------------------------------------------------------
-----------------------------------------------------------------------------
-- | Calculated liveness info for a CmmGraph
-----------------------------------------------------------------------------
-cmmLivenessZ :: CmmGraph -> BlockEntryLiveness
-cmmLivenessZ g = env
- where env = runDFA liveLattice $
- do run_b_anal transfer g
- allFacts
- transfer = BComp "liveness analysis" exit last middle first
- exit = emptyUniqSet
- first live _ = live
- middle = flip middleLiveness
- last = flip lastLiveness
+cmmLivenessZ :: CmmGraph -> FuelMonad BlockEntryLiveness
+cmmLivenessZ g = liftM zdfFpFacts $ (res :: FuelMonad (CmmBackwardFixedPoint CmmLive))
+ where res = zdfSolveFrom emptyBlockEnv "liveness analysis" liveLattice transfers
+ emptyUniqSet (graphOfLGraph g)
+ transfers = BackwardTransfers first middle last
+ first live _ = live
+ middle = flip middleLiveness
+ last = flip lastLiveness
-- | The transfer equations use the traditional 'gen' and 'kill'
-- notations, which should be familiar from the dragon book.
middleLiveness :: Middle -> CmmLive -> CmmLive
middleLiveness m = middle m
- where middle (MidNop) = id
- middle (MidComment {}) = id
+ where middle (MidComment {}) = id
middle (MidAssign lhs expr) = gen expr . kill lhs
middle (MidStore addr rval) = gen addr . gen rval
middle (MidUnsafeCall tgt ress args) = gen tgt . gen args . kill ress
+ middle (MidAddToContext ra args) = gen ra . gen args
middle (CopyIn _ formals _) = kill formals
- middle (CopyOut _ formals) = gen formals
+ middle (CopyOut _ actuals) = gen actuals
lastLiveness :: Last -> (BlockId -> CmmLive) -> CmmLive
lastLiveness l env = last l
- where last (LastReturn ress) = gen ress emptyUniqSet
- last (LastJump e args) = gen e $ gen args emptyUniqSet
- last (LastBranch id args) = gen args $ env id
+ where last (LastReturn) = emptyUniqSet
+ last (LastJump e) = gen e $ emptyUniqSet
+ last (LastBranch id) = env id
last (LastCall tgt (Just k)) = gen tgt $ env k
last (LastCall tgt Nothing) = gen tgt $ emptyUniqSet
last (LastCondBranch e t f) = gen e $ unionUniqSets (env t) (env f)