blob: ca474ef61c182d5950087e5d4342b360a03231de (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE ScopedTypeVariables #-}
module CmmLive
( CmmLocalLive
, cmmLocalLiveness
, cmmGlobalLiveness
, liveLattice
, gen_kill
)
where
import GhcPrelude
import DynFlags
import BlockId
import Cmm
import PprCmmExpr () -- For Outputable instances
import Hoopl.Block
import Hoopl.Collections
import Hoopl.Dataflow
import Hoopl.Label
import Maybes
import Outputable
-----------------------------------------------------------------------------
-- Calculating what variables are live on entry to a basic block
-----------------------------------------------------------------------------
-- | The variables live on entry to a block
type CmmLive r = RegSet r
type CmmLocalLive = CmmLive LocalReg
-- | The dataflow lattice
liveLattice :: Ord r => DataflowLattice (CmmLive r)
{-# SPECIALIZE liveLattice :: DataflowLattice (CmmLive LocalReg) #-}
{-# SPECIALIZE liveLattice :: DataflowLattice (CmmLive GlobalReg) #-}
liveLattice = DataflowLattice emptyRegSet add
where
add (OldFact old) (NewFact new) =
let !join = plusRegSet old new
in changedIf (sizeRegSet join > sizeRegSet old) join
-- | A mapping from block labels to the variables live on entry
type BlockEntryLiveness r = LabelMap (CmmLive r)
-----------------------------------------------------------------------------
-- | Calculated liveness info for a CmmGraph
-----------------------------------------------------------------------------
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
-- | On entry to the procedure, there had better not be any LocalReg's live-in.
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
{-# INLINE gen_kill #-}
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
{-# SPECIALIZE xferLive :: DynFlags -> TransferFun (CmmLive LocalReg) #-}
{-# SPECIALIZE xferLive :: DynFlags -> TransferFun (CmmLive GlobalReg) #-}
|
