{-# LANGUAGE GADTs, DisambiguateRecordFields, BangPatterns #-}

module CmmProcPoint
    ( ProcPointSet, Status(..)
    , callProcPoints, minimalProcPointSet
    , splitAtProcPoints, procPointAnalysis
    , attachContInfoTables
    )
where

import GhcPrelude hiding (last, unzip, succ, zip)

import DynFlags
import BlockId
import CLabel
import Cmm
import PprCmm () -- For Outputable instances
import CmmUtils
import CmmInfo
import CmmLive
import CmmSwitch
import Data.List (sortBy)
import Maybes
import Control.Monad
import Outputable
import GHC.Platform
import UniqSupply
import Hoopl.Block
import Hoopl.Collections
import Hoopl.Dataflow
import Hoopl.Graph
import Hoopl.Label

-- Compute a minimal set of proc points for a control-flow graph.

-- Determine a protocol for each proc point (which live variables will
-- be passed as arguments and which will be on the stack).

{-
A proc point is a basic block that, after CPS transformation, will
start a new function.  The entry block of the original function is a
proc point, as is the continuation of each function call.
A third kind of proc point arises if we want to avoid copying code.
Suppose we have code like the following:

  f() {
    if (...) { ..1..; call foo(); ..2..}
    else     { ..3..; call bar(); ..4..}
    x = y + z;
    return x;
  }

The statement 'x = y + z' can be reached from two different proc
points: the continuations of foo() and bar().  We would prefer not to
put a copy in each continuation; instead we would like 'x = y + z' to
be the start of a new procedure to which the continuations can jump:

  f_cps () {
    if (...) { ..1..; push k_foo; jump foo_cps(); }
    else     { ..3..; push k_bar; jump bar_cps(); }
  }
  k_foo() { ..2..; jump k_join(y, z); }
  k_bar() { ..4..; jump k_join(y, z); }
  k_join(y, z) { x = y + z; return x; }

You might think then that a criterion to make a node a proc point is
that it is directly reached by two distinct proc points.  (Note
[Direct reachability].)  But this criterion is a bit too simple; for
example, 'return x' is also reached by two proc points, yet there is
no point in pulling it out of k_join.  A good criterion would be to
say that a node should be made a proc point if it is reached by a set
of proc points that is different than its immediate dominator.  NR
believes this criterion can be shown to produce a minimum set of proc
points, and given a dominator tree, the proc points can be chosen in
time linear in the number of blocks.  Lacking a dominator analysis,
however, we turn instead to an iterative solution, starting with no
proc points and adding them according to these rules:

  1. The entry block is a proc point.
  2. The continuation of a call is a proc point.
  3. A node is a proc point if it is directly reached by more proc
     points than one of its predecessors.

Because we don't understand the problem very well, we apply rule 3 at
most once per iteration, then recompute the reachability information.
(See Note [No simple dataflow].)  The choice of the new proc point is
arbitrary, and I don't know if the choice affects the final solution,
so I don't know if the number of proc points chosen is the
minimum---but the set will be minimal.



Note [Proc-point analysis]
~~~~~~~~~~~~~~~~~~~~~~~~~~

Given a specified set of proc-points (a set of block-ids), "proc-point
analysis" figures out, for every block, which proc-point it belongs to.
All the blocks belonging to proc-point P will constitute a single
top-level C procedure.

A non-proc-point block B "belongs to" a proc-point P iff B is
reachable from P without going through another proc-point.

Invariant: a block B should belong to at most one proc-point; if it
belongs to two, that's a bug.

Note [Non-existing proc-points]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On some architectures it might happen that the list of proc-points
computed before stack layout pass will be invalidated by the stack
layout. This will happen if stack layout removes from the graph
blocks that were determined to be proc-points. Later on in the pipeline
we use list of proc-points to perform [Proc-point analysis], but
if a proc-point does not exist anymore then we will get compiler panic.
See #8205.
-}

type ProcPointSet = LabelSet

data Status
  = ReachedBy ProcPointSet  -- set of proc points that directly reach the block
  | ProcPoint               -- this block is itself a proc point

instance Outputable Status where
  ppr :: Status -> SDoc
ppr (ReachedBy ProcPointSet
ps)
      | ProcPointSet -> Bool
forall set. IsSet set => set -> Bool
setNull ProcPointSet
ps = String -> SDoc
text String
"<not-reached>"
      | Bool
otherwise = String -> SDoc
text String
"reached by" SDoc -> SDoc -> SDoc
<+>
                    ([SDoc] -> SDoc
hsep ([SDoc] -> SDoc) -> [SDoc] -> SDoc
forall a b. (a -> b) -> a -> b
$ SDoc -> [SDoc] -> [SDoc]
punctuate SDoc
comma ([SDoc] -> [SDoc]) -> [SDoc] -> [SDoc]
forall a b. (a -> b) -> a -> b
$ (Label -> SDoc) -> [Label] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map Label -> SDoc
forall a. Outputable a => a -> SDoc
ppr ([Label] -> [SDoc]) -> [Label] -> [SDoc]
forall a b. (a -> b) -> a -> b
$ ProcPointSet -> [ElemOf ProcPointSet]
forall set. IsSet set => set -> [ElemOf set]
setElems ProcPointSet
ps)
  ppr Status
ProcPoint = String -> SDoc
text String
"<procpt>"

--------------------------------------------------
-- Proc point analysis

-- Once you know what the proc-points are, figure out
-- what proc-points each block is reachable from
-- See Note [Proc-point analysis]
procPointAnalysis :: ProcPointSet -> CmmGraph -> LabelMap Status
procPointAnalysis :: ProcPointSet -> CmmGraph -> LabelMap Status
procPointAnalysis ProcPointSet
procPoints cmmGraph :: CmmGraph
cmmGraph@(CmmGraph {g_graph :: forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Graph n C C
g_graph = Graph CmmNode C C
graph}) =
    DataflowLattice Status
-> TransferFun Status
-> CmmGraph
-> LabelMap Status
-> LabelMap Status
forall f.
DataflowLattice f
-> TransferFun f -> CmmGraph -> FactBase f -> FactBase f
analyzeCmmFwd DataflowLattice Status
procPointLattice TransferFun Status
procPointTransfer CmmGraph
cmmGraph LabelMap Status
initProcPoints
  where
    initProcPoints :: LabelMap Status
initProcPoints =
        DataflowLattice Status -> [(Label, Status)] -> LabelMap Status
forall f. DataflowLattice f -> [(Label, f)] -> FactBase f
mkFactBase
            DataflowLattice Status
procPointLattice
            [ (Label
id, Status
ProcPoint)
            | Label
id <- ProcPointSet -> [ElemOf ProcPointSet]
forall set. IsSet set => set -> [ElemOf set]
setElems ProcPointSet
procPoints
            -- See Note [Non-existing proc-points]
            , ElemOf ProcPointSet
Label
id ElemOf ProcPointSet -> ProcPointSet -> Bool
forall set. IsSet set => ElemOf set -> set -> Bool
`setMember` ProcPointSet
labelsInGraph
            ]
    labelsInGraph :: ProcPointSet
labelsInGraph = Graph CmmNode C C -> ProcPointSet
forall (block :: (Extensibility -> Extensibility -> *)
                 -> Extensibility -> Extensibility -> *)
       (n :: Extensibility -> Extensibility -> *) (e :: Extensibility)
       (x :: Extensibility).
NonLocal (block n) =>
Graph' block n e x -> ProcPointSet
labelsDefined Graph CmmNode C C
graph

procPointTransfer :: TransferFun Status
procPointTransfer :: TransferFun Status
procPointTransfer CmmBlock
block LabelMap Status
facts =
    let label :: Label
label = CmmBlock -> Label
forall (thing :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
NonLocal thing =>
thing C x -> Label
entryLabel CmmBlock
block
        !fact :: Status
fact = case DataflowLattice Status -> Label -> LabelMap Status -> Status
forall f. DataflowLattice f -> Label -> FactBase f -> f
getFact DataflowLattice Status
procPointLattice Label
label LabelMap Status
facts of
            Status
ProcPoint -> ProcPointSet -> Status
ReachedBy (ProcPointSet -> Status) -> ProcPointSet -> Status
forall a b. (a -> b) -> a -> b
$! ElemOf ProcPointSet -> ProcPointSet
forall set. IsSet set => ElemOf set -> set
setSingleton ElemOf ProcPointSet
Label
label
            Status
f -> Status
f
        result :: [(Label, Status)]
result = (Label -> (Label, Status)) -> [Label] -> [(Label, Status)]
forall a b. (a -> b) -> [a] -> [b]
map (\Label
id -> (Label
id, Status
fact)) (CmmBlock -> [Label]
forall (thing :: Extensibility -> Extensibility -> *)
       (e :: Extensibility).
NonLocal thing =>
thing e C -> [Label]
successors CmmBlock
block)
    in DataflowLattice Status -> [(Label, Status)] -> LabelMap Status
forall f. DataflowLattice f -> [(Label, f)] -> FactBase f
mkFactBase DataflowLattice Status
procPointLattice [(Label, Status)]
result

procPointLattice :: DataflowLattice Status
procPointLattice :: DataflowLattice Status
procPointLattice = Status -> JoinFun Status -> DataflowLattice Status
forall a. a -> JoinFun a -> DataflowLattice a
DataflowLattice Status
unreached JoinFun Status
add_to
  where
    unreached :: Status
unreached = ProcPointSet -> Status
ReachedBy ProcPointSet
forall set. IsSet set => set
setEmpty
    add_to :: JoinFun Status
add_to (OldFact Status
ProcPoint) NewFact Status
_ = Status -> JoinedFact Status
forall a. a -> JoinedFact a
NotChanged Status
ProcPoint
    add_to OldFact Status
_ (NewFact Status
ProcPoint) = Status -> JoinedFact Status
forall a. a -> JoinedFact a
Changed Status
ProcPoint -- because of previous case
    add_to (OldFact (ReachedBy ProcPointSet
p)) (NewFact (ReachedBy ProcPointSet
p'))
        | ProcPointSet -> Int
forall set. IsSet set => set -> Int
setSize ProcPointSet
union Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> ProcPointSet -> Int
forall set. IsSet set => set -> Int
setSize ProcPointSet
p = Status -> JoinedFact Status
forall a. a -> JoinedFact a
Changed (ProcPointSet -> Status
ReachedBy ProcPointSet
union)
        | Bool
otherwise = Status -> JoinedFact Status
forall a. a -> JoinedFact a
NotChanged (ProcPointSet -> Status
ReachedBy ProcPointSet
p)
      where
        union :: ProcPointSet
union = ProcPointSet -> ProcPointSet -> ProcPointSet
forall set. IsSet set => set -> set -> set
setUnion ProcPointSet
p' ProcPointSet
p

----------------------------------------------------------------------

-- It is worth distinguishing two sets of proc points: those that are
-- induced by calls in the original graph and those that are
-- introduced because they're reachable from multiple proc points.
--
-- Extract the set of Continuation BlockIds, see Note [Continuation BlockIds].
callProcPoints      :: CmmGraph -> ProcPointSet
callProcPoints :: CmmGraph -> ProcPointSet
callProcPoints CmmGraph
g = (ProcPointSet -> CmmBlock -> ProcPointSet)
-> ProcPointSet -> CmmGraph -> ProcPointSet
forall a. (a -> CmmBlock -> a) -> a -> CmmGraph -> a
foldlGraphBlocks ProcPointSet -> CmmBlock -> ProcPointSet
add (ElemOf ProcPointSet -> ProcPointSet
forall set. IsSet set => ElemOf set -> set
setSingleton (CmmGraph -> Label
forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Label
g_entry CmmGraph
g)) CmmGraph
g
  where add :: LabelSet -> CmmBlock -> LabelSet
        add :: ProcPointSet -> CmmBlock -> ProcPointSet
add ProcPointSet
set CmmBlock
b = case CmmBlock -> CmmNode O C
forall (n :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
Block n x C -> n O C
lastNode CmmBlock
b of
                      CmmCall {cml_cont :: CmmNode O C -> Maybe Label
cml_cont = Just Label
k} -> ElemOf ProcPointSet -> ProcPointSet -> ProcPointSet
forall set. IsSet set => ElemOf set -> set -> set
setInsert ElemOf ProcPointSet
Label
k ProcPointSet
set
                      CmmForeignCall {succ :: CmmNode O C -> Label
succ=Label
k}     -> ElemOf ProcPointSet -> ProcPointSet -> ProcPointSet
forall set. IsSet set => ElemOf set -> set -> set
setInsert ElemOf ProcPointSet
Label
k ProcPointSet
set
                      CmmNode O C
_ -> ProcPointSet
set

minimalProcPointSet :: Platform -> ProcPointSet -> CmmGraph
                    -> UniqSM ProcPointSet
-- Given the set of successors of calls (which must be proc-points)
-- figure out the minimal set of necessary proc-points
minimalProcPointSet :: Platform -> ProcPointSet -> CmmGraph -> UniqSM ProcPointSet
minimalProcPointSet Platform
platform ProcPointSet
callProcPoints CmmGraph
g
  = Platform
-> CmmGraph -> [CmmBlock] -> ProcPointSet -> UniqSM ProcPointSet
extendPPSet Platform
platform CmmGraph
g (CmmGraph -> [CmmBlock]
revPostorder CmmGraph
g) ProcPointSet
callProcPoints

extendPPSet
    :: Platform -> CmmGraph -> [CmmBlock] -> ProcPointSet -> UniqSM ProcPointSet
extendPPSet :: Platform
-> CmmGraph -> [CmmBlock] -> ProcPointSet -> UniqSM ProcPointSet
extendPPSet Platform
platform CmmGraph
g [CmmBlock]
blocks ProcPointSet
procPoints =
    let env :: LabelMap Status
env = ProcPointSet -> CmmGraph -> LabelMap Status
procPointAnalysis ProcPointSet
procPoints CmmGraph
g
        add :: ProcPointSet -> CmmBlock -> ProcPointSet
add ProcPointSet
pps CmmBlock
block = let id :: Label
id = CmmBlock -> Label
forall (thing :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
NonLocal thing =>
thing C x -> Label
entryLabel CmmBlock
block
                        in  case KeyOf LabelMap -> LabelMap Status -> Maybe Status
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
id LabelMap Status
env of
                              Just Status
ProcPoint -> ElemOf ProcPointSet -> ProcPointSet -> ProcPointSet
forall set. IsSet set => ElemOf set -> set -> set
setInsert ElemOf ProcPointSet
Label
id ProcPointSet
pps
                              Maybe Status
_ -> ProcPointSet
pps
        procPoints' :: ProcPointSet
procPoints' = (ProcPointSet -> CmmBlock -> ProcPointSet)
-> ProcPointSet -> CmmGraph -> ProcPointSet
forall a. (a -> CmmBlock -> a) -> a -> CmmGraph -> a
foldlGraphBlocks ProcPointSet -> CmmBlock -> ProcPointSet
add ProcPointSet
forall set. IsSet set => set
setEmpty CmmGraph
g
        newPoints :: [Label]
newPoints = (CmmBlock -> Maybe Label) -> [CmmBlock] -> [Label]
forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe CmmBlock -> Maybe Label
ppSuccessor [CmmBlock]
blocks
        newPoint :: Maybe Label
newPoint  = [Label] -> Maybe Label
forall a. [a] -> Maybe a
listToMaybe [Label]
newPoints
        ppSuccessor :: CmmBlock -> Maybe Label
ppSuccessor CmmBlock
b =
            let nreached :: Label -> Int
nreached Label
id = case KeyOf LabelMap -> LabelMap Status -> Maybe Status
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
id LabelMap Status
env Maybe Status -> Status -> Status
forall a. Maybe a -> a -> a
`orElse`
                                    String -> SDoc -> Status
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"no ppt" (Label -> SDoc
forall a. Outputable a => a -> SDoc
ppr Label
id SDoc -> SDoc -> SDoc
<+> CmmBlock -> SDoc
forall a. Outputable a => a -> SDoc
ppr CmmBlock
b) of
                                Status
ProcPoint -> Int
1
                                ReachedBy ProcPointSet
ps -> ProcPointSet -> Int
forall set. IsSet set => set -> Int
setSize ProcPointSet
ps
                block_procpoints :: Int
block_procpoints = Label -> Int
nreached (CmmBlock -> Label
forall (thing :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
NonLocal thing =>
thing C x -> Label
entryLabel CmmBlock
b)
                -- | Looking for a successor of b that is reached by
                -- more proc points than b and is not already a proc
                -- point.  If found, it can become a proc point.
                newId :: Label -> Bool
newId Label
succ_id = Bool -> Bool
not (ElemOf ProcPointSet -> ProcPointSet -> Bool
forall set. IsSet set => ElemOf set -> set -> Bool
setMember ElemOf ProcPointSet
Label
succ_id ProcPointSet
procPoints') Bool -> Bool -> Bool
&&
                                Label -> Int
nreached Label
succ_id Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
> Int
block_procpoints
            in  [Label] -> Maybe Label
forall a. [a] -> Maybe a
listToMaybe ([Label] -> Maybe Label) -> [Label] -> Maybe Label
forall a b. (a -> b) -> a -> b
$ (Label -> Bool) -> [Label] -> [Label]
forall a. (a -> Bool) -> [a] -> [a]
filter Label -> Bool
newId ([Label] -> [Label]) -> [Label] -> [Label]
forall a b. (a -> b) -> a -> b
$ CmmBlock -> [Label]
forall (thing :: Extensibility -> Extensibility -> *)
       (e :: Extensibility).
NonLocal thing =>
thing e C -> [Label]
successors CmmBlock
b

    in case Maybe Label
newPoint of
         Just Label
id ->
             if ElemOf ProcPointSet -> ProcPointSet -> Bool
forall set. IsSet set => ElemOf set -> set -> Bool
setMember ElemOf ProcPointSet
Label
id ProcPointSet
procPoints'
                then String -> UniqSM ProcPointSet
forall a. String -> a
panic String
"added old proc pt"
                else Platform
-> CmmGraph -> [CmmBlock] -> ProcPointSet -> UniqSM ProcPointSet
extendPPSet Platform
platform CmmGraph
g [CmmBlock]
blocks (ElemOf ProcPointSet -> ProcPointSet -> ProcPointSet
forall set. IsSet set => ElemOf set -> set -> set
setInsert ElemOf ProcPointSet
Label
id ProcPointSet
procPoints')
         Maybe Label
Nothing -> ProcPointSet -> UniqSM ProcPointSet
forall (m :: * -> *) a. Monad m => a -> m a
return ProcPointSet
procPoints'


-- At this point, we have found a set of procpoints, each of which should be
-- the entry point of a procedure.
-- Now, we create the procedure for each proc point,
-- which requires that we:
-- 1. build a map from proc points to the blocks reachable from the proc point
-- 2. turn each branch to a proc point into a jump
-- 3. turn calls and returns into jumps
-- 4. build info tables for the procedures -- and update the info table for
--    the SRTs in the entry procedure as well.
-- Input invariant: A block should only be reachable from a single ProcPoint.
-- ToDo: use the _ret naming convention that the old code generator
-- used. -- EZY
splitAtProcPoints :: DynFlags -> CLabel -> ProcPointSet-> ProcPointSet -> LabelMap Status ->
                     CmmDecl -> UniqSM [CmmDecl]
splitAtProcPoints :: DynFlags
-> CLabel
-> ProcPointSet
-> ProcPointSet
-> LabelMap Status
-> CmmDecl
-> UniqSM [CmmDecl]
splitAtProcPoints DynFlags
dflags CLabel
entry_label ProcPointSet
callPPs ProcPointSet
procPoints LabelMap Status
procMap
                  (CmmProc (TopInfo {info_tbls :: CmmTopInfo -> LabelMap CmmInfoTable
info_tbls = LabelMap CmmInfoTable
info_tbls})
                           CLabel
top_l [GlobalReg]
_ g :: CmmGraph
g@(CmmGraph {g_entry :: forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Label
g_entry=Label
entry})) =
  do -- Build a map from procpoints to the blocks they reach
     let add_block
             :: LabelMap (LabelMap CmmBlock)
             -> CmmBlock
             -> LabelMap (LabelMap CmmBlock)
         add_block :: LabelMap (LabelMap CmmBlock)
-> CmmBlock -> LabelMap (LabelMap CmmBlock)
add_block LabelMap (LabelMap CmmBlock)
graphEnv CmmBlock
b =
           case KeyOf LabelMap -> LabelMap Status -> Maybe Status
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
bid LabelMap Status
procMap of
             Just Status
ProcPoint -> LabelMap (LabelMap CmmBlock)
-> KeyOf LabelMap
-> KeyOf LabelMap
-> CmmBlock
-> LabelMap (LabelMap CmmBlock)
forall (map :: * -> *) (map :: * -> *) a.
(IsMap map, IsMap map) =>
map (map a) -> KeyOf map -> KeyOf map -> a -> map (map a)
add LabelMap (LabelMap CmmBlock)
graphEnv KeyOf LabelMap
Label
bid KeyOf LabelMap
Label
bid CmmBlock
b
             Just (ReachedBy ProcPointSet
set) ->
               case ProcPointSet -> [ElemOf ProcPointSet]
forall set. IsSet set => set -> [ElemOf set]
setElems ProcPointSet
set of
                 []   -> LabelMap (LabelMap CmmBlock)
graphEnv
                 [ElemOf ProcPointSet
id] -> LabelMap (LabelMap CmmBlock)
-> KeyOf LabelMap
-> KeyOf LabelMap
-> CmmBlock
-> LabelMap (LabelMap CmmBlock)
forall (map :: * -> *) (map :: * -> *) a.
(IsMap map, IsMap map) =>
map (map a) -> KeyOf map -> KeyOf map -> a -> map (map a)
add LabelMap (LabelMap CmmBlock)
graphEnv KeyOf LabelMap
ElemOf ProcPointSet
id KeyOf LabelMap
Label
bid CmmBlock
b
                 [ElemOf ProcPointSet]
_    -> String -> LabelMap (LabelMap CmmBlock)
forall a. String -> a
panic String
"Each block should be reachable from only one ProcPoint"
             Maybe Status
Nothing -> LabelMap (LabelMap CmmBlock)
graphEnv
           where bid :: Label
bid = CmmBlock -> Label
forall (thing :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
NonLocal thing =>
thing C x -> Label
entryLabel CmmBlock
b
         add :: map (map a) -> KeyOf map -> KeyOf map -> a -> map (map a)
add map (map a)
graphEnv KeyOf map
procId KeyOf map
bid a
b = KeyOf map -> map a -> map (map a) -> map (map a)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert KeyOf map
procId map a
graph' map (map a)
graphEnv
               where graph :: map a
graph  = KeyOf map -> map (map a) -> Maybe (map a)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf map
procId map (map a)
graphEnv Maybe (map a) -> map a -> map a
forall a. Maybe a -> a -> a
`orElse` map a
forall (map :: * -> *) a. IsMap map => map a
mapEmpty
                     graph' :: map a
graph' = KeyOf map -> a -> map a -> map a
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert KeyOf map
bid a
b map a
graph

     let liveness :: BlockEntryLiveness GlobalReg
liveness = DynFlags -> CmmGraph -> BlockEntryLiveness GlobalReg
cmmGlobalLiveness DynFlags
dflags CmmGraph
g
     let ppLiveness :: Label -> [GlobalReg]
ppLiveness Label
pp = (GlobalReg -> Bool) -> [GlobalReg] -> [GlobalReg]
forall a. (a -> Bool) -> [a] -> [a]
filter GlobalReg -> Bool
isArgReg ([GlobalReg] -> [GlobalReg]) -> [GlobalReg] -> [GlobalReg]
forall a b. (a -> b) -> a -> b
$
                         RegSet GlobalReg -> [GlobalReg]
forall r. RegSet r -> [r]
regSetToList (RegSet GlobalReg -> [GlobalReg])
-> RegSet GlobalReg -> [GlobalReg]
forall a b. (a -> b) -> a -> b
$
                         String -> Maybe (RegSet GlobalReg) -> RegSet GlobalReg
forall a. HasCallStack => String -> Maybe a -> a
expectJust String
"ppLiveness" (Maybe (RegSet GlobalReg) -> RegSet GlobalReg)
-> Maybe (RegSet GlobalReg) -> RegSet GlobalReg
forall a b. (a -> b) -> a -> b
$ KeyOf LabelMap
-> BlockEntryLiveness GlobalReg -> Maybe (RegSet GlobalReg)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
pp BlockEntryLiveness GlobalReg
liveness

     LabelMap (LabelMap CmmBlock)
graphEnv <- LabelMap (LabelMap CmmBlock)
-> UniqSM (LabelMap (LabelMap CmmBlock))
forall (m :: * -> *) a. Monad m => a -> m a
return (LabelMap (LabelMap CmmBlock)
 -> UniqSM (LabelMap (LabelMap CmmBlock)))
-> LabelMap (LabelMap CmmBlock)
-> UniqSM (LabelMap (LabelMap CmmBlock))
forall a b. (a -> b) -> a -> b
$ (LabelMap (LabelMap CmmBlock)
 -> CmmBlock -> LabelMap (LabelMap CmmBlock))
-> LabelMap (LabelMap CmmBlock)
-> CmmGraph
-> LabelMap (LabelMap CmmBlock)
forall a. (a -> CmmBlock -> a) -> a -> CmmGraph -> a
foldlGraphBlocks LabelMap (LabelMap CmmBlock)
-> CmmBlock -> LabelMap (LabelMap CmmBlock)
add_block LabelMap (LabelMap CmmBlock)
forall (map :: * -> *) a. IsMap map => map a
mapEmpty CmmGraph
g

     -- Build a map from proc point BlockId to pairs of:
     --  * Labels for their new procedures
     --  * Labels for the info tables of their new procedures (only if
     --    the proc point is a callPP)
     -- Due to common blockification, we may overestimate the set of procpoints.
     let add_label :: LabelMap (CLabel, Maybe CLabel)
-> Label -> LabelMap (CLabel, Maybe CLabel)
add_label LabelMap (CLabel, Maybe CLabel)
map Label
pp = KeyOf LabelMap
-> (CLabel, Maybe CLabel)
-> LabelMap (CLabel, Maybe CLabel)
-> LabelMap (CLabel, Maybe CLabel)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert KeyOf LabelMap
Label
pp (CLabel, Maybe CLabel)
lbls LabelMap (CLabel, Maybe CLabel)
map
           where lbls :: (CLabel, Maybe CLabel)
lbls | Label
pp Label -> Label -> Bool
forall a. Eq a => a -> a -> Bool
== Label
entry = (CLabel
entry_label, (CmmInfoTable -> CLabel) -> Maybe CmmInfoTable -> Maybe CLabel
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap CmmInfoTable -> CLabel
cit_lbl (KeyOf LabelMap -> LabelMap CmmInfoTable -> Maybe CmmInfoTable
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
entry LabelMap CmmInfoTable
info_tbls))
                      | Bool
otherwise   = (CLabel
block_lbl, Bool -> Maybe ()
forall (f :: * -> *). Alternative f => Bool -> f ()
guard (ElemOf ProcPointSet -> ProcPointSet -> Bool
forall set. IsSet set => ElemOf set -> set -> Bool
setMember ElemOf ProcPointSet
Label
pp ProcPointSet
callPPs) Maybe () -> Maybe CLabel -> Maybe CLabel
forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>>
                                                    CLabel -> Maybe CLabel
forall a. a -> Maybe a
Just CLabel
info_table_lbl)
                      where block_lbl :: CLabel
block_lbl      = Label -> CLabel
blockLbl Label
pp
                            info_table_lbl :: CLabel
info_table_lbl = Label -> CLabel
infoTblLbl Label
pp

         procLabels :: LabelMap (CLabel, Maybe CLabel)
         procLabels :: LabelMap (CLabel, Maybe CLabel)
procLabels = (LabelMap (CLabel, Maybe CLabel)
 -> Label -> LabelMap (CLabel, Maybe CLabel))
-> LabelMap (CLabel, Maybe CLabel)
-> [Label]
-> LabelMap (CLabel, Maybe CLabel)
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' LabelMap (CLabel, Maybe CLabel)
-> Label -> LabelMap (CLabel, Maybe CLabel)
add_label LabelMap (CLabel, Maybe CLabel)
forall (map :: * -> *) a. IsMap map => map a
mapEmpty
                             ((Label -> Bool) -> [Label] -> [Label]
forall a. (a -> Bool) -> [a] -> [a]
filter ((Label -> LabelMap CmmBlock -> Bool)
-> LabelMap CmmBlock -> Label -> Bool
forall a b c. (a -> b -> c) -> b -> a -> c
flip Label -> LabelMap CmmBlock -> Bool
forall (map :: * -> *) a. IsMap map => KeyOf map -> map a -> Bool
mapMember (CmmGraph -> LabelMap CmmBlock
toBlockMap CmmGraph
g)) (ProcPointSet -> [ElemOf ProcPointSet]
forall set. IsSet set => set -> [ElemOf set]
setElems ProcPointSet
procPoints))

     -- In each new graph, add blocks jumping off to the new procedures,
     -- and replace branches to procpoints with branches to the jump-off blocks
     let add_jump_block
             :: (LabelMap Label, [CmmBlock])
             -> (Label, CLabel)
             -> UniqSM (LabelMap Label, [CmmBlock])
         add_jump_block :: (LabelMap Label, [CmmBlock])
-> (Label, CLabel) -> UniqSM (LabelMap Label, [CmmBlock])
add_jump_block (LabelMap Label
env, [CmmBlock]
bs) (Label
pp, CLabel
l) =
           do Label
bid <- (Unique -> Label) -> UniqSM Unique -> UniqSM Label
forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r
liftM Unique -> Label
mkBlockId UniqSM Unique
forall (m :: * -> *). MonadUnique m => m Unique
getUniqueM
              let b :: CmmBlock
b = CmmNode C O -> Block CmmNode O O -> CmmNode O C -> CmmBlock
forall (n :: Extensibility -> Extensibility -> *).
n C O -> Block n O O -> n O C -> Block n C C
blockJoin (Label -> CmmTickScope -> CmmNode C O
CmmEntry Label
bid CmmTickScope
GlobalScope) Block CmmNode O O
forall (n :: Extensibility -> Extensibility -> *). Block n O O
emptyBlock CmmNode O C
jump
                  live :: [GlobalReg]
live = Label -> [GlobalReg]
ppLiveness Label
pp
                  jump :: CmmNode O C
jump = CmmExpr
-> Maybe Label -> [GlobalReg] -> Int -> Int -> Int -> CmmNode O C
CmmCall (CmmLit -> CmmExpr
CmmLit (CLabel -> CmmLit
CmmLabel CLabel
l)) Maybe Label
forall a. Maybe a
Nothing [GlobalReg]
live Int
0 Int
0 Int
0
              (LabelMap Label, [CmmBlock]) -> UniqSM (LabelMap Label, [CmmBlock])
forall (m :: * -> *) a. Monad m => a -> m a
return (KeyOf LabelMap -> Label -> LabelMap Label -> LabelMap Label
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert KeyOf LabelMap
Label
pp Label
bid LabelMap Label
env, CmmBlock
b CmmBlock -> [CmmBlock] -> [CmmBlock]
forall a. a -> [a] -> [a]
: [CmmBlock]
bs)

         add_jumps
             :: LabelMap CmmGraph
             -> (Label, LabelMap CmmBlock)
             -> UniqSM (LabelMap CmmGraph)
         add_jumps :: LabelMap CmmGraph
-> (Label, LabelMap CmmBlock) -> UniqSM (LabelMap CmmGraph)
add_jumps LabelMap CmmGraph
newGraphEnv (Label
ppId, LabelMap CmmBlock
blockEnv) =
           do let needed_jumps :: [(Label, CLabel)]
needed_jumps = -- find which procpoints we currently branch to
                    (CmmBlock -> [(Label, CLabel)] -> [(Label, CLabel)])
-> [(Label, CLabel)] -> LabelMap CmmBlock -> [(Label, CLabel)]
forall (map :: * -> *) a b.
IsMap map =>
(a -> b -> b) -> b -> map a -> b
mapFoldr CmmBlock -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_branch_to_pp [] LabelMap CmmBlock
blockEnv
                  add_if_branch_to_pp :: CmmBlock -> [(BlockId, CLabel)] -> [(BlockId, CLabel)]
                  add_if_branch_to_pp :: CmmBlock -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_branch_to_pp CmmBlock
block [(Label, CLabel)]
rst =
                    case CmmBlock -> CmmNode O C
forall (n :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
Block n x C -> n O C
lastNode CmmBlock
block of
                      CmmBranch Label
id          -> Label -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_pp Label
id [(Label, CLabel)]
rst
                      CmmCondBranch CmmExpr
_ Label
ti Label
fi Maybe Bool
_ -> Label -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_pp Label
ti (Label -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_pp Label
fi [(Label, CLabel)]
rst)
                      CmmSwitch CmmExpr
_ SwitchTargets
ids       -> (Label -> [(Label, CLabel)] -> [(Label, CLabel)])
-> [(Label, CLabel)] -> [Label] -> [(Label, CLabel)]
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr Label -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_pp [(Label, CLabel)]
rst ([Label] -> [(Label, CLabel)]) -> [Label] -> [(Label, CLabel)]
forall a b. (a -> b) -> a -> b
$ SwitchTargets -> [Label]
switchTargetsToList SwitchTargets
ids
                      CmmNode O C
_                     -> [(Label, CLabel)]
rst

                  -- when jumping to a PP that has an info table, if
                  -- tablesNextToCode is off we must jump to the entry
                  -- label instead.
                  jump_label :: Maybe CLabel -> CLabel -> CLabel
jump_label (Just CLabel
info_lbl) CLabel
_
                             | DynFlags -> Bool
tablesNextToCode DynFlags
dflags = CLabel
info_lbl
                             | Bool
otherwise               = CLabel -> CLabel
toEntryLbl CLabel
info_lbl
                  jump_label Maybe CLabel
Nothing         CLabel
block_lbl = CLabel
block_lbl

                  add_if_pp :: Label -> [(Label, CLabel)] -> [(Label, CLabel)]
add_if_pp Label
id [(Label, CLabel)]
rst = case KeyOf LabelMap
-> LabelMap (CLabel, Maybe CLabel) -> Maybe (CLabel, Maybe CLabel)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
id LabelMap (CLabel, Maybe CLabel)
procLabels of
                                       Just (CLabel
lbl, Maybe CLabel
mb_info_lbl) -> (Label
id, Maybe CLabel -> CLabel -> CLabel
jump_label Maybe CLabel
mb_info_lbl CLabel
lbl) (Label, CLabel) -> [(Label, CLabel)] -> [(Label, CLabel)]
forall a. a -> [a] -> [a]
: [(Label, CLabel)]
rst
                                       Maybe (CLabel, Maybe CLabel)
Nothing                 -> [(Label, CLabel)]
rst
              (LabelMap Label
jumpEnv, [CmmBlock]
jumpBlocks) <-
                 ((LabelMap Label, [CmmBlock])
 -> (Label, CLabel) -> UniqSM (LabelMap Label, [CmmBlock]))
-> (LabelMap Label, [CmmBlock])
-> [(Label, CLabel)]
-> UniqSM (LabelMap Label, [CmmBlock])
forall (t :: * -> *) (m :: * -> *) b a.
(Foldable t, Monad m) =>
(b -> a -> m b) -> b -> t a -> m b
foldM (LabelMap Label, [CmmBlock])
-> (Label, CLabel) -> UniqSM (LabelMap Label, [CmmBlock])
add_jump_block (LabelMap Label
forall (map :: * -> *) a. IsMap map => map a
mapEmpty, []) [(Label, CLabel)]
needed_jumps
                  -- update the entry block
              let b :: CmmBlock
b = String -> Maybe CmmBlock -> CmmBlock
forall a. HasCallStack => String -> Maybe a -> a
expectJust String
"block in env" (Maybe CmmBlock -> CmmBlock) -> Maybe CmmBlock -> CmmBlock
forall a b. (a -> b) -> a -> b
$ KeyOf LabelMap -> LabelMap CmmBlock -> Maybe CmmBlock
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
ppId LabelMap CmmBlock
blockEnv
                  blockEnv' :: LabelMap CmmBlock
blockEnv' = KeyOf LabelMap
-> CmmBlock -> LabelMap CmmBlock -> LabelMap CmmBlock
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert KeyOf LabelMap
Label
ppId CmmBlock
b LabelMap CmmBlock
blockEnv
                  -- replace branches to procpoints with branches to jumps
                  blockEnv'' :: LabelMap CmmBlock
blockEnv'' = CmmGraph -> LabelMap CmmBlock
toBlockMap (CmmGraph -> LabelMap CmmBlock) -> CmmGraph -> LabelMap CmmBlock
forall a b. (a -> b) -> a -> b
$ LabelMap Label -> CmmGraph -> CmmGraph
replaceBranches LabelMap Label
jumpEnv (CmmGraph -> CmmGraph) -> CmmGraph -> CmmGraph
forall a b. (a -> b) -> a -> b
$ Label -> LabelMap CmmBlock -> CmmGraph
ofBlockMap Label
ppId LabelMap CmmBlock
blockEnv'
                  -- add the jump blocks to the graph
                  blockEnv''' :: LabelMap CmmBlock
blockEnv''' = (LabelMap CmmBlock -> CmmBlock -> LabelMap CmmBlock)
-> LabelMap CmmBlock -> [CmmBlock] -> LabelMap CmmBlock
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' ((CmmBlock -> LabelMap CmmBlock -> LabelMap CmmBlock)
-> LabelMap CmmBlock -> CmmBlock -> LabelMap CmmBlock
forall a b c. (a -> b -> c) -> b -> a -> c
flip CmmBlock -> LabelMap CmmBlock -> LabelMap CmmBlock
forall (block :: Extensibility -> Extensibility -> *).
(NonLocal block, HasDebugCallStack) =>
block C C -> LabelMap (block C C) -> LabelMap (block C C)
addBlock) LabelMap CmmBlock
blockEnv'' [CmmBlock]
jumpBlocks
              let g' :: CmmGraph
g' = Label -> LabelMap CmmBlock -> CmmGraph
ofBlockMap Label
ppId LabelMap CmmBlock
blockEnv'''
              -- pprTrace "g' pre jumps" (ppr g') $ do
              LabelMap CmmGraph -> UniqSM (LabelMap CmmGraph)
forall (m :: * -> *) a. Monad m => a -> m a
return (KeyOf LabelMap
-> CmmGraph -> LabelMap CmmGraph -> LabelMap CmmGraph
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert KeyOf LabelMap
Label
ppId CmmGraph
g' LabelMap CmmGraph
newGraphEnv)

     LabelMap CmmGraph
graphEnv <- (LabelMap CmmGraph
 -> (Label, LabelMap CmmBlock) -> UniqSM (LabelMap CmmGraph))
-> LabelMap CmmGraph
-> [(Label, LabelMap CmmBlock)]
-> UniqSM (LabelMap CmmGraph)
forall (t :: * -> *) (m :: * -> *) b a.
(Foldable t, Monad m) =>
(b -> a -> m b) -> b -> t a -> m b
foldM LabelMap CmmGraph
-> (Label, LabelMap CmmBlock) -> UniqSM (LabelMap CmmGraph)
add_jumps LabelMap CmmGraph
forall (map :: * -> *) a. IsMap map => map a
mapEmpty ([(Label, LabelMap CmmBlock)] -> UniqSM (LabelMap CmmGraph))
-> [(Label, LabelMap CmmBlock)] -> UniqSM (LabelMap CmmGraph)
forall a b. (a -> b) -> a -> b
$ LabelMap (LabelMap CmmBlock)
-> [(KeyOf LabelMap, LabelMap CmmBlock)]
forall (map :: * -> *) a. IsMap map => map a -> [(KeyOf map, a)]
mapToList LabelMap (LabelMap CmmBlock)
graphEnv

     let to_proc :: (Label, CmmGraph) -> CmmDecl
to_proc (Label
bid, CmmGraph
g)
             | Label
bid Label -> Label -> Bool
forall a. Eq a => a -> a -> Bool
== Label
entry
             =  CmmTopInfo -> CLabel -> [GlobalReg] -> CmmGraph -> CmmDecl
forall d h g. h -> CLabel -> [GlobalReg] -> g -> GenCmmDecl d h g
CmmProc (TopInfo :: LabelMap CmmInfoTable -> CmmStackInfo -> CmmTopInfo
TopInfo {info_tbls :: LabelMap CmmInfoTable
info_tbls  = LabelMap CmmInfoTable
info_tbls,
                                  stack_info :: CmmStackInfo
stack_info = CmmStackInfo
stack_info})
                        CLabel
top_l [GlobalReg]
live CmmGraph
g'
             | Bool
otherwise
             = case String -> Maybe (CLabel, Maybe CLabel) -> (CLabel, Maybe CLabel)
forall a. HasCallStack => String -> Maybe a -> a
expectJust String
"pp label" (Maybe (CLabel, Maybe CLabel) -> (CLabel, Maybe CLabel))
-> Maybe (CLabel, Maybe CLabel) -> (CLabel, Maybe CLabel)
forall a b. (a -> b) -> a -> b
$ KeyOf LabelMap
-> LabelMap (CLabel, Maybe CLabel) -> Maybe (CLabel, Maybe CLabel)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
bid LabelMap (CLabel, Maybe CLabel)
procLabels of
                 (CLabel
lbl, Just CLabel
info_lbl)
                    -> CmmTopInfo -> CLabel -> [GlobalReg] -> CmmGraph -> CmmDecl
forall d h g. h -> CLabel -> [GlobalReg] -> g -> GenCmmDecl d h g
CmmProc (TopInfo :: LabelMap CmmInfoTable -> CmmStackInfo -> CmmTopInfo
TopInfo { info_tbls :: LabelMap CmmInfoTable
info_tbls = KeyOf LabelMap -> CmmInfoTable -> LabelMap CmmInfoTable
forall (map :: * -> *) a. IsMap map => KeyOf map -> a -> map a
mapSingleton (CmmGraph -> Label
forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Label
g_entry CmmGraph
g) (CLabel -> CmmInfoTable
mkEmptyContInfoTable CLabel
info_lbl)
                                        , stack_info :: CmmStackInfo
stack_info=CmmStackInfo
stack_info})
                               CLabel
lbl [GlobalReg]
live CmmGraph
g'
                 (CLabel
lbl, Maybe CLabel
Nothing)
                    -> CmmTopInfo -> CLabel -> [GlobalReg] -> CmmGraph -> CmmDecl
forall d h g. h -> CLabel -> [GlobalReg] -> g -> GenCmmDecl d h g
CmmProc (TopInfo :: LabelMap CmmInfoTable -> CmmStackInfo -> CmmTopInfo
TopInfo {info_tbls :: LabelMap CmmInfoTable
info_tbls = LabelMap CmmInfoTable
forall (map :: * -> *) a. IsMap map => map a
mapEmpty, stack_info :: CmmStackInfo
stack_info=CmmStackInfo
stack_info})
                               CLabel
lbl [GlobalReg]
live CmmGraph
g'
                where
                 g' :: CmmGraph
g' = CmmGraph -> CmmGraph
replacePPIds CmmGraph
g
                 live :: [GlobalReg]
live = Label -> [GlobalReg]
ppLiveness (CmmGraph -> Label
forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Label
g_entry CmmGraph
g')
                 stack_info :: CmmStackInfo
stack_info = StackInfo :: Int -> Maybe Int -> Bool -> CmmStackInfo
StackInfo { arg_space :: Int
arg_space = Int
0
                                        , updfr_space :: Maybe Int
updfr_space =  Maybe Int
forall a. Maybe a
Nothing
                                        , do_layout :: Bool
do_layout = Bool
True }
                               -- cannot use panic, this is printed by -ddump-cmm

         -- References to procpoint IDs can now be replaced with the
         -- infotable's label
         replacePPIds :: CmmGraph -> CmmGraph
replacePPIds CmmGraph
g = {-# SCC "replacePPIds" #-}
                          (CmmNode C O -> CmmNode C O, CmmNode O O -> CmmNode O O,
 CmmNode O C -> CmmNode O C)
-> CmmGraph -> CmmGraph
mapGraphNodes (CmmNode C O -> CmmNode C O
forall a. a -> a
id, (CmmExpr -> CmmExpr) -> CmmNode O O -> CmmNode O O
forall (e :: Extensibility) (x :: Extensibility).
(CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExp CmmExpr -> CmmExpr
repl, (CmmExpr -> CmmExpr) -> CmmNode O C -> CmmNode O C
forall (e :: Extensibility) (x :: Extensibility).
(CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExp CmmExpr -> CmmExpr
repl) CmmGraph
g
           where repl :: CmmExpr -> CmmExpr
repl e :: CmmExpr
e@(CmmLit (CmmBlock Label
bid)) =
                   case KeyOf LabelMap
-> LabelMap (CLabel, Maybe CLabel) -> Maybe (CLabel, Maybe CLabel)
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
bid LabelMap (CLabel, Maybe CLabel)
procLabels of
                     Just (CLabel
_, Just CLabel
info_lbl)  -> CmmLit -> CmmExpr
CmmLit (CLabel -> CmmLit
CmmLabel CLabel
info_lbl)
                     Maybe (CLabel, Maybe CLabel)
_ -> CmmExpr
e
                 repl CmmExpr
e = CmmExpr
e

     -- The C back end expects to see return continuations before the
     -- call sites.  Here, we sort them in reverse order -- it gets
     -- reversed later.
     let (Int
_, LabelMap Int
block_order) =
             ((Int, LabelMap Int) -> CmmBlock -> (Int, LabelMap Int))
-> (Int, LabelMap Int) -> [CmmBlock] -> (Int, LabelMap Int)
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' (Int, LabelMap Int) -> CmmBlock -> (Int, LabelMap Int)
forall a (map :: * -> *)
       (thing :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
(Num a, IsMap map, NonLocal thing, KeyOf map ~ Label) =>
(a, map a) -> thing C x -> (a, map a)
add_block_num (Int
0::Int, LabelMap Int
forall (map :: * -> *) a. IsMap map => map a
mapEmpty :: LabelMap Int)
                   (CmmGraph -> [CmmBlock]
revPostorder CmmGraph
g)
         add_block_num :: (a, map a) -> thing C x -> (a, map a)
add_block_num (a
i, map a
map) thing C x
block =
           (a
i a -> a -> a
forall a. Num a => a -> a -> a
+ a
1, KeyOf map -> a -> map a -> map a
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> a -> map a -> map a
mapInsert (thing C x -> Label
forall (thing :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
NonLocal thing =>
thing C x -> Label
entryLabel thing C x
block) a
i map a
map)
         sort_fn :: (Label, CmmGraph) -> (Label, CmmGraph) -> Ordering
sort_fn (Label
bid, CmmGraph
_) (Label
bid', CmmGraph
_) =
           Int -> Int -> Ordering
forall a. Ord a => a -> a -> Ordering
compare (String -> Maybe Int -> Int
forall a. HasCallStack => String -> Maybe a -> a
expectJust String
"block_order" (Maybe Int -> Int) -> Maybe Int -> Int
forall a b. (a -> b) -> a -> b
$ KeyOf LabelMap -> LabelMap Int -> Maybe Int
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
bid  LabelMap Int
block_order)
                   (String -> Maybe Int -> Int
forall a. HasCallStack => String -> Maybe a -> a
expectJust String
"block_order" (Maybe Int -> Int) -> Maybe Int -> Int
forall a b. (a -> b) -> a -> b
$ KeyOf LabelMap -> LabelMap Int -> Maybe Int
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
bid' LabelMap Int
block_order)
     [CmmDecl]
procs <- [CmmDecl] -> UniqSM [CmmDecl]
forall (m :: * -> *) a. Monad m => a -> m a
return ([CmmDecl] -> UniqSM [CmmDecl]) -> [CmmDecl] -> UniqSM [CmmDecl]
forall a b. (a -> b) -> a -> b
$ ((Label, CmmGraph) -> CmmDecl) -> [(Label, CmmGraph)] -> [CmmDecl]
forall a b. (a -> b) -> [a] -> [b]
map (Label, CmmGraph) -> CmmDecl
to_proc ([(Label, CmmGraph)] -> [CmmDecl])
-> [(Label, CmmGraph)] -> [CmmDecl]
forall a b. (a -> b) -> a -> b
$ ((Label, CmmGraph) -> (Label, CmmGraph) -> Ordering)
-> [(Label, CmmGraph)] -> [(Label, CmmGraph)]
forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy (Label, CmmGraph) -> (Label, CmmGraph) -> Ordering
sort_fn ([(Label, CmmGraph)] -> [(Label, CmmGraph)])
-> [(Label, CmmGraph)] -> [(Label, CmmGraph)]
forall a b. (a -> b) -> a -> b
$ LabelMap CmmGraph -> [(KeyOf LabelMap, CmmGraph)]
forall (map :: * -> *) a. IsMap map => map a -> [(KeyOf map, a)]
mapToList LabelMap CmmGraph
graphEnv
     [CmmDecl] -> UniqSM [CmmDecl]
forall (m :: * -> *) a. Monad m => a -> m a
return -- pprTrace "procLabels" (ppr procLabels)
            -- pprTrace "splitting graphs" (ppr procs)
            [CmmDecl]
procs
splitAtProcPoints DynFlags
_ CLabel
_ ProcPointSet
_ ProcPointSet
_ LabelMap Status
_ t :: CmmDecl
t@(CmmData Section
_ CmmStatics
_) = [CmmDecl] -> UniqSM [CmmDecl]
forall (m :: * -> *) a. Monad m => a -> m a
return [CmmDecl
t]

-- Only called from CmmProcPoint.splitAtProcPoints. NB. does a
-- recursive lookup, see comment below.
replaceBranches :: LabelMap BlockId -> CmmGraph -> CmmGraph
replaceBranches :: LabelMap Label -> CmmGraph -> CmmGraph
replaceBranches LabelMap Label
env CmmGraph
cmmg
  = {-# SCC "replaceBranches" #-}
    Label -> LabelMap CmmBlock -> CmmGraph
ofBlockMap (CmmGraph -> Label
forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Label
g_entry CmmGraph
cmmg) (LabelMap CmmBlock -> CmmGraph) -> LabelMap CmmBlock -> CmmGraph
forall a b. (a -> b) -> a -> b
$ (CmmBlock -> CmmBlock) -> LabelMap CmmBlock -> LabelMap CmmBlock
forall (map :: * -> *) a b. IsMap map => (a -> b) -> map a -> map b
mapMap CmmBlock -> CmmBlock
forall (x :: Extensibility). Block CmmNode x C -> Block CmmNode x C
f (LabelMap CmmBlock -> LabelMap CmmBlock)
-> LabelMap CmmBlock -> LabelMap CmmBlock
forall a b. (a -> b) -> a -> b
$ CmmGraph -> LabelMap CmmBlock
toBlockMap CmmGraph
cmmg
  where
    f :: Block CmmNode x C -> Block CmmNode x C
f Block CmmNode x C
block = Block CmmNode x C -> CmmNode O C -> Block CmmNode x C
forall (n :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
Block n x C -> n O C -> Block n x C
replaceLastNode Block CmmNode x C
block (CmmNode O C -> Block CmmNode x C)
-> CmmNode O C -> Block CmmNode x C
forall a b. (a -> b) -> a -> b
$ CmmNode O C -> CmmNode O C
last (Block CmmNode x C -> CmmNode O C
forall (n :: Extensibility -> Extensibility -> *)
       (x :: Extensibility).
Block n x C -> n O C
lastNode Block CmmNode x C
block)

    last :: CmmNode O C -> CmmNode O C
    last :: CmmNode O C -> CmmNode O C
last (CmmBranch Label
id)          = Label -> CmmNode O C
CmmBranch (Label -> Label
lookup Label
id)
    last (CmmCondBranch CmmExpr
e Label
ti Label
fi Maybe Bool
l) = CmmExpr -> Label -> Label -> Maybe Bool -> CmmNode O C
CmmCondBranch CmmExpr
e (Label -> Label
lookup Label
ti) (Label -> Label
lookup Label
fi) Maybe Bool
l
    last (CmmSwitch CmmExpr
e SwitchTargets
ids)       = CmmExpr -> SwitchTargets -> CmmNode O C
CmmSwitch CmmExpr
e ((Label -> Label) -> SwitchTargets -> SwitchTargets
mapSwitchTargets Label -> Label
lookup SwitchTargets
ids)
    last l :: CmmNode O C
l@(CmmCall {})          = CmmNode O C
l { cml_cont :: Maybe Label
cml_cont = Maybe Label
forall a. Maybe a
Nothing }
            -- NB. remove the continuation of a CmmCall, since this
            -- label will now be in a different CmmProc.  Not only
            -- is this tidier, it stops CmmLint from complaining.
    last l :: CmmNode O C
l@(CmmForeignCall {})   = CmmNode O C
l
    lookup :: Label -> Label
lookup Label
id = (Label -> Label) -> Maybe Label -> Maybe Label
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap Label -> Label
lookup (KeyOf LabelMap -> LabelMap Label -> Maybe Label
forall (map :: * -> *) a.
IsMap map =>
KeyOf map -> map a -> Maybe a
mapLookup KeyOf LabelMap
Label
id LabelMap Label
env) Maybe Label -> Label -> Label
forall a. Maybe a -> a -> a
`orElse` Label
id
            -- XXX: this is a recursive lookup, it follows chains
            -- until the lookup returns Nothing, at which point we
            -- return the last BlockId

-- --------------------------------------------------------------
-- Not splitting proc points: add info tables for continuations

attachContInfoTables :: ProcPointSet -> CmmDecl -> CmmDecl
attachContInfoTables :: ProcPointSet -> CmmDecl -> CmmDecl
attachContInfoTables ProcPointSet
call_proc_points (CmmProc CmmTopInfo
top_info CLabel
top_l [GlobalReg]
live CmmGraph
g)
 = CmmTopInfo -> CLabel -> [GlobalReg] -> CmmGraph -> CmmDecl
forall d h g. h -> CLabel -> [GlobalReg] -> g -> GenCmmDecl d h g
CmmProc CmmTopInfo
top_info{info_tbls :: LabelMap CmmInfoTable
info_tbls = LabelMap CmmInfoTable
info_tbls'} CLabel
top_l [GlobalReg]
live CmmGraph
g
 where
   info_tbls' :: LabelMap CmmInfoTable
info_tbls' = LabelMap CmmInfoTable
-> LabelMap CmmInfoTable -> LabelMap CmmInfoTable
forall (map :: * -> *) a. IsMap map => map a -> map a -> map a
mapUnion (CmmTopInfo -> LabelMap CmmInfoTable
info_tbls CmmTopInfo
top_info) (LabelMap CmmInfoTable -> LabelMap CmmInfoTable)
-> LabelMap CmmInfoTable -> LabelMap CmmInfoTable
forall a b. (a -> b) -> a -> b
$
                [(KeyOf LabelMap, CmmInfoTable)] -> LabelMap CmmInfoTable
forall (map :: * -> *) a. IsMap map => [(KeyOf map, a)] -> map a
mapFromList [ (KeyOf LabelMap
Label
l, CLabel -> CmmInfoTable
mkEmptyContInfoTable (Label -> CLabel
infoTblLbl Label
l))
                            | Label
l <- ProcPointSet -> [ElemOf ProcPointSet]
forall set. IsSet set => set -> [ElemOf set]
setElems ProcPointSet
call_proc_points
                            , Label
l Label -> Label -> Bool
forall a. Eq a => a -> a -> Bool
/= CmmGraph -> Label
forall (n :: Extensibility -> Extensibility -> *).
GenCmmGraph n -> Label
g_entry CmmGraph
g ]
attachContInfoTables ProcPointSet
_ CmmDecl
other_decl
 = CmmDecl
other_decl

----------------------------------------------------------------

{-
Note [Direct reachability]

Block B is directly reachable from proc point P iff control can flow
from P to B without passing through an intervening proc point.
-}

----------------------------------------------------------------

{-
Note [No simple dataflow]

Sadly, it seems impossible to compute the proc points using a single
dataflow pass.  One might attempt to use this simple lattice:

  data Location = Unknown
                | InProc BlockId -- node is in procedure headed by the named proc point
                | ProcPoint      -- node is itself a proc point

At a join, a node in two different blocks becomes a proc point.
The difficulty is that the change of information during iterative
computation may promote a node prematurely.  Here's a program that
illustrates the difficulty:

  f () {
  entry:
    ....
  L1:
    if (...) { ... }
    else { ... }

  L2: if (...) { g(); goto L1; }
      return x + y;
  }

The only proc-point needed (besides the entry) is L1.  But in an
iterative analysis, consider what happens to L2.  On the first pass
through, it rises from Unknown to 'InProc entry', but when L1 is
promoted to a proc point (because it's the successor of g()), L1's
successors will be promoted to 'InProc L1'.  The problem hits when the
new fact 'InProc L1' flows into L2 which is already bound to 'InProc entry'.
The join operation makes it a proc point when in fact it needn't be,
because its immediate dominator L1 is already a proc point and there
are no other proc points that directly reach L2.
-}



{- Note [Separate Adams optimization]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It may be worthwhile to attempt the Adams optimization by rewriting
the graph before the assignment of proc-point protocols.  Here are a
couple of rules:

  g() returns to k;                    g() returns to L;
  k: CopyIn c ress; goto L:
   ...                        ==>        ...
  L: // no CopyIn node here            L: CopyIn c ress;


And when c == c' and ress == ress', this also:

  g() returns to k;                    g() returns to L;
  k: CopyIn c ress; goto L:
   ...                        ==>        ...
  L: CopyIn c' ress'                   L: CopyIn c' ress' ;

In both cases the goal is to eliminate k.
-}