module CmmLive
( CmmLocalLive
, cmmLocalLiveness
, cmmGlobalLiveness
, liveLattice
, gen_kill
)
where
import GhcPrelude
import DynFlags
import BlockId
import Cmm
import PprCmmExpr ()
import Hoopl.Block
import Hoopl.Collections
import Hoopl.Dataflow
import Hoopl.Label
import Maybes
import Outputable
type CmmLive r = RegSet r
type CmmLocalLive = CmmLive LocalReg
liveLattice :: Ord r => DataflowLattice (CmmLive r)
liveLattice = DataflowLattice emptyRegSet add
where
add (OldFact old) (NewFact new) =
let !join = plusRegSet old new
in changedIf (sizeRegSet join > sizeRegSet old) join
type BlockEntryLiveness r = LabelMap (CmmLive r)
cmmLocalLiveness :: DynFlags -> CmmGraph -> BlockEntryLiveness LocalReg
cmmLocalLiveness dflags graph =
check $ analyzeCmmBwd liveLattice (xferLive dflags) graph mapEmpty
where
entry = g_entry graph
check facts =
noLiveOnEntry entry (expectJust "check" $ mapLookup entry facts) facts
cmmGlobalLiveness :: DynFlags -> CmmGraph -> BlockEntryLiveness GlobalReg
cmmGlobalLiveness dflags graph =
analyzeCmmBwd liveLattice (xferLive dflags) graph mapEmpty
noLiveOnEntry :: BlockId -> CmmLive LocalReg -> a -> a
noLiveOnEntry bid in_fact x =
if nullRegSet in_fact then x
else pprPanic "LocalReg's live-in to graph" (ppr bid <+> ppr in_fact)
gen_kill
:: (DefinerOfRegs r n, UserOfRegs r n)
=> DynFlags -> n -> CmmLive r -> CmmLive r
gen_kill dflags node set =
let !afterKill = foldRegsDefd dflags deleteFromRegSet set node
in foldRegsUsed dflags extendRegSet afterKill node
xferLive
:: forall r.
( UserOfRegs r (CmmNode O O)
, DefinerOfRegs r (CmmNode O O)
, UserOfRegs r (CmmNode O C)
, DefinerOfRegs r (CmmNode O C)
)
=> DynFlags -> TransferFun (CmmLive r)
xferLive dflags (BlockCC eNode middle xNode) fBase =
let joined = gen_kill dflags xNode $! joinOutFacts liveLattice xNode fBase
!result = foldNodesBwdOO (gen_kill dflags) middle joined
in mapSingleton (entryLabel eNode) result