{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE ExplicitForAll #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE ScopedTypeVariables #-}


-- CmmNode type for representation using Hoopl graphs.

module CmmNode (
     CmmNode(..), CmmFormal, CmmActual, CmmTickish,
     UpdFrameOffset, Convention(..),
     ForeignConvention(..), ForeignTarget(..), foreignTargetHints,
     CmmReturnInfo(..),
     mapExp, mapExpDeep, wrapRecExp, foldExp, foldExpDeep, wrapRecExpf,
     mapExpM, mapExpDeepM, wrapRecExpM, mapSuccessors, mapCollectSuccessors,

     -- * Tick scopes
     CmmTickScope(..), isTickSubScope, combineTickScopes,
  ) where

import GhcPrelude hiding (succ)

import CodeGen.Platform
import CmmExpr
import CmmSwitch
import DynFlags
import FastString
import ForeignCall
import Outputable
import SMRep
import CoreSyn (Tickish)
import qualified Unique as U

import Hoopl.Block
import Hoopl.Graph
import Hoopl.Collections
import Hoopl.Label
import Data.Maybe
import Data.List (tails,sortBy)
import Unique (nonDetCmpUnique)
import Util


------------------------
-- CmmNode

#define ULabel {-# UNPACK #-} !Label

data CmmNode e x where
  CmmEntry :: ULabel -> CmmTickScope -> CmmNode C O

  CmmComment :: FastString -> CmmNode O O

    -- Tick annotation, covering Cmm code in our tick scope. We only
    -- expect non-code @Tickish@ at this point (e.g. @SourceNote@).
    -- See Note [CmmTick scoping details]
  CmmTick :: !CmmTickish -> CmmNode O O

    -- Unwind pseudo-instruction, encoding stack unwinding
    -- instructions for a debugger. This describes how to reconstruct
    -- the "old" value of a register if we want to navigate the stack
    -- up one frame. Having unwind information for @Sp@ will allow the
    -- debugger to "walk" the stack.
    --
    -- See Note [What is this unwinding business?] in Debug
  CmmUnwind :: [(GlobalReg, Maybe CmmExpr)] -> CmmNode O O

  CmmAssign :: !CmmReg -> !CmmExpr -> CmmNode O O
    -- Assign to register

  CmmStore :: !CmmExpr -> !CmmExpr -> CmmNode O O
    -- Assign to memory location.  Size is
    -- given by cmmExprType of the rhs.

  CmmUnsafeForeignCall ::       -- An unsafe foreign call;
                                -- see Note [Foreign calls]
                                -- Like a "fat machine instruction"; can occur
                                -- in the middle of a block
      ForeignTarget ->          -- call target
      [CmmFormal] ->            -- zero or more results
      [CmmActual] ->            -- zero or more arguments
      CmmNode O O
      -- Semantics: clobbers any GlobalRegs for which callerSaves r == True
      -- See Note [Unsafe foreign calls clobber caller-save registers]
      --
      -- Invariant: the arguments and the ForeignTarget must not
      -- mention any registers for which CodeGen.Platform.callerSaves
      -- is True.  See Note [Register Parameter Passing].

  CmmBranch :: ULabel -> CmmNode O C
                                   -- Goto another block in the same procedure

  CmmCondBranch :: {                 -- conditional branch
      CmmNode O C -> CmmExpr
cml_pred :: CmmExpr,
      CmmNode O C -> Label
cml_true, CmmNode O C -> Label
cml_false :: ULabel,
      CmmNode O C -> Maybe Bool
cml_likely :: Maybe Bool       -- likely result of the conditional,
                                     -- if known
  } -> CmmNode O C

  CmmSwitch
    :: CmmExpr       -- Scrutinee, of some integral type
    -> SwitchTargets -- Cases. See [Note SwitchTargets]
    -> CmmNode O C

  CmmCall :: {                -- A native call or tail call
      CmmNode O C -> CmmExpr
cml_target :: CmmExpr,  -- never a CmmPrim to a CallishMachOp!

      CmmNode O C -> Maybe Label
cml_cont :: Maybe Label,
          -- Label of continuation (Nothing for return or tail call)
          --
          -- Note [Continuation BlockId]: these BlockIds are called
          -- Continuation BlockIds, and are the only BlockIds that can
          -- occur in CmmExprs, namely as (CmmLit (CmmBlock b)) or
          -- (CmmStackSlot (Young b) _).

      CmmNode O C -> [GlobalReg]
cml_args_regs :: [GlobalReg],
          -- The argument GlobalRegs (Rx, Fx, Dx, Lx) that are passed
          -- to the call.  This is essential information for the
          -- native code generator's register allocator; without
          -- knowing which GlobalRegs are live it has to assume that
          -- they are all live.  This list should only include
          -- GlobalRegs that are mapped to real machine registers on
          -- the target platform.

      CmmNode O C -> ByteOff
cml_args :: ByteOff,
          -- Byte offset, from the *old* end of the Area associated with
          -- the Label (if cml_cont = Nothing, then Old area), of
          -- youngest outgoing arg.  Set the stack pointer to this before
          -- transferring control.
          -- (NB: an update frame might also have been stored in the Old
          --      area, but it'll be in an older part than the args.)

      CmmNode O C -> ByteOff
cml_ret_args :: ByteOff,
          -- For calls *only*, the byte offset for youngest returned value
          -- This is really needed at the *return* point rather than here
          -- at the call, but in practice it's convenient to record it here.

      CmmNode O C -> ByteOff
cml_ret_off :: ByteOff
        -- For calls *only*, the byte offset of the base of the frame that
        -- must be described by the info table for the return point.
        -- The older words are an update frames, which have their own
        -- info-table and layout information

        -- From a liveness point of view, the stack words older than
        -- cml_ret_off are treated as live, even if the sequel of
        -- the call goes into a loop.
  } -> CmmNode O C

  CmmForeignCall :: {           -- A safe foreign call; see Note [Foreign calls]
                                -- Always the last node of a block
      CmmNode O C -> ForeignTarget
tgt   :: ForeignTarget,   -- call target and convention
      CmmNode O C -> [CmmFormal]
res   :: [CmmFormal],     -- zero or more results
      CmmNode O C -> [CmmExpr]
args  :: [CmmActual],     -- zero or more arguments; see Note [Register parameter passing]
      CmmNode O C -> Label
succ  :: ULabel,          -- Label of continuation
      CmmNode O C -> ByteOff
ret_args :: ByteOff,      -- same as cml_ret_args
      CmmNode O C -> ByteOff
ret_off :: ByteOff,       -- same as cml_ret_off
      CmmNode O C -> Bool
intrbl:: Bool             -- whether or not the call is interruptible
  } -> CmmNode O C

{- Note [Foreign calls]
~~~~~~~~~~~~~~~~~~~~~~~
A CmmUnsafeForeignCall is used for *unsafe* foreign calls;
a CmmForeignCall call is used for *safe* foreign calls.

Unsafe ones are mostly easy: think of them as a "fat machine
instruction".  In particular, they do *not* kill all live registers,
just the registers they return to (there was a bit of code in GHC that
conservatively assumed otherwise.)  However, see [Register parameter passing].

Safe ones are trickier.  A safe foreign call
     r = f(x)
ultimately expands to
     push "return address"      -- Never used to return to;
                                -- just points an info table
     save registers into TSO
     call suspendThread
     r = f(x)                   -- Make the call
     call resumeThread
     restore registers
     pop "return address"
We cannot "lower" a safe foreign call to this sequence of Cmms, because
after we've saved Sp all the Cmm optimiser's assumptions are broken.

Note that a safe foreign call needs an info table.

So Safe Foreign Calls must remain as last nodes until the stack is
made manifest in CmmLayoutStack, where they are lowered into the above
sequence.
-}

{- Note [Unsafe foreign calls clobber caller-save registers]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A foreign call is defined to clobber any GlobalRegs that are mapped to
caller-saves machine registers (according to the prevailing C ABI).
StgCmmUtils.callerSaves tells you which GlobalRegs are caller-saves.

This is a design choice that makes it easier to generate code later.
We could instead choose to say that foreign calls do *not* clobber
caller-saves regs, but then we would have to figure out which regs
were live across the call later and insert some saves/restores.

Furthermore when we generate code we never have any GlobalRegs live
across a call, because they are always copied-in to LocalRegs and
copied-out again before making a call/jump.  So all we have to do is
avoid any code motion that would make a caller-saves GlobalReg live
across a foreign call during subsequent optimisations.
-}

{- Note [Register parameter passing]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
On certain architectures, some registers are utilized for parameter
passing in the C calling convention.  For example, in x86-64 Linux
convention, rdi, rsi, rdx and rcx (as well as r8 and r9) may be used for
argument passing.  These are registers R3-R6, which our generated
code may also be using; as a result, it's necessary to save these
values before doing a foreign call.  This is done during initial
code generation in callerSaveVolatileRegs in StgCmmUtils.hs.  However,
one result of doing this is that the contents of these registers
may mysteriously change if referenced inside the arguments.  This
is dangerous, so you'll need to disable inlining much in the same
way is done in cmm/CmmOpt.hs currently.  We should fix this!
-}

---------------------------------------------
-- Eq instance of CmmNode

deriving instance Eq (CmmNode e x)

----------------------------------------------
-- Hoopl instances of CmmNode

instance NonLocal CmmNode where
  entryLabel :: CmmNode C x -> Label
entryLabel (CmmEntry l :: Label
l _) = Label
l

  successors :: CmmNode e C -> [Label]
successors (CmmBranch l :: Label
l) = [Label
l]
  successors (CmmCondBranch {cml_true :: CmmNode O C -> Label
cml_true=Label
t, cml_false :: CmmNode O C -> Label
cml_false=Label
f}) = [Label
f, Label
t] -- meets layout constraint
  successors (CmmSwitch _ ids :: SwitchTargets
ids) = SwitchTargets -> [Label]
switchTargetsToList SwitchTargets
ids
  successors (CmmCall {cml_cont :: CmmNode O C -> Maybe Label
cml_cont=Maybe Label
l}) = Maybe Label -> [Label]
forall a. Maybe a -> [a]
maybeToList Maybe Label
l
  successors (CmmForeignCall {succ :: CmmNode O C -> Label
succ=Label
l}) = [Label
l]


--------------------------------------------------
-- Various helper types

type CmmActual = CmmExpr
type CmmFormal = LocalReg

type UpdFrameOffset = ByteOff

-- | A convention maps a list of values (function arguments or return
-- values) to registers or stack locations.
data Convention
  = NativeDirectCall
       -- ^ top-level Haskell functions use @NativeDirectCall@, which
       -- maps arguments to registers starting with R2, according to
       -- how many registers are available on the platform.  This
       -- convention ignores R1, because for a top-level function call
       -- the function closure is implicit, and doesn't need to be passed.
  | NativeNodeCall
       -- ^ non-top-level Haskell functions, which pass the address of
       -- the function closure in R1 (regardless of whether R1 is a
       -- real register or not), and the rest of the arguments in
       -- registers or on the stack.
  | NativeReturn
       -- ^ a native return.  The convention for returns depends on
       -- how many values are returned: for just one value returned,
       -- the appropriate register is used (R1, F1, etc.). regardless
       -- of whether it is a real register or not.  For multiple
       -- values returned, they are mapped to registers or the stack.
  | Slow
       -- ^ Slow entry points: all args pushed on the stack
  | GC
       -- ^ Entry to the garbage collector: uses the node reg!
       -- (TODO: I don't think we need this --SDM)
  deriving( Convention -> Convention -> Bool
(Convention -> Convention -> Bool)
-> (Convention -> Convention -> Bool) -> Eq Convention
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: Convention -> Convention -> Bool
$c/= :: Convention -> Convention -> Bool
== :: Convention -> Convention -> Bool
$c== :: Convention -> Convention -> Bool
Eq )

data ForeignConvention
  = ForeignConvention
        CCallConv               -- Which foreign-call convention
        [ForeignHint]           -- Extra info about the args
        [ForeignHint]           -- Extra info about the result
        CmmReturnInfo
  deriving ForeignConvention -> ForeignConvention -> Bool
(ForeignConvention -> ForeignConvention -> Bool)
-> (ForeignConvention -> ForeignConvention -> Bool)
-> Eq ForeignConvention
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: ForeignConvention -> ForeignConvention -> Bool
$c/= :: ForeignConvention -> ForeignConvention -> Bool
== :: ForeignConvention -> ForeignConvention -> Bool
$c== :: ForeignConvention -> ForeignConvention -> Bool
Eq

data CmmReturnInfo
  = CmmMayReturn
  | CmmNeverReturns
  deriving ( CmmReturnInfo -> CmmReturnInfo -> Bool
(CmmReturnInfo -> CmmReturnInfo -> Bool)
-> (CmmReturnInfo -> CmmReturnInfo -> Bool) -> Eq CmmReturnInfo
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: CmmReturnInfo -> CmmReturnInfo -> Bool
$c/= :: CmmReturnInfo -> CmmReturnInfo -> Bool
== :: CmmReturnInfo -> CmmReturnInfo -> Bool
$c== :: CmmReturnInfo -> CmmReturnInfo -> Bool
Eq )

data ForeignTarget        -- The target of a foreign call
  = ForeignTarget                -- A foreign procedure
        CmmExpr                  -- Its address
        ForeignConvention        -- Its calling convention
  | PrimTarget            -- A possibly-side-effecting machine operation
        CallishMachOp            -- Which one
  deriving ForeignTarget -> ForeignTarget -> Bool
(ForeignTarget -> ForeignTarget -> Bool)
-> (ForeignTarget -> ForeignTarget -> Bool) -> Eq ForeignTarget
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: ForeignTarget -> ForeignTarget -> Bool
$c/= :: ForeignTarget -> ForeignTarget -> Bool
== :: ForeignTarget -> ForeignTarget -> Bool
$c== :: ForeignTarget -> ForeignTarget -> Bool
Eq

foreignTargetHints :: ForeignTarget -> ([ForeignHint], [ForeignHint])
foreignTargetHints :: ForeignTarget -> ([ForeignHint], [ForeignHint])
foreignTargetHints target :: ForeignTarget
target
  = ( [ForeignHint]
res_hints [ForeignHint] -> [ForeignHint] -> [ForeignHint]
forall a. [a] -> [a] -> [a]
++ ForeignHint -> [ForeignHint]
forall a. a -> [a]
repeat ForeignHint
NoHint
    , [ForeignHint]
arg_hints [ForeignHint] -> [ForeignHint] -> [ForeignHint]
forall a. [a] -> [a] -> [a]
++ ForeignHint -> [ForeignHint]
forall a. a -> [a]
repeat ForeignHint
NoHint )
  where
    (res_hints :: [ForeignHint]
res_hints, arg_hints :: [ForeignHint]
arg_hints) =
       case ForeignTarget
target of
          PrimTarget op :: CallishMachOp
op -> CallishMachOp -> ([ForeignHint], [ForeignHint])
callishMachOpHints CallishMachOp
op
          ForeignTarget _ (ForeignConvention _ arg_hints :: [ForeignHint]
arg_hints res_hints :: [ForeignHint]
res_hints _) ->
             ([ForeignHint]
res_hints, [ForeignHint]
arg_hints)

--------------------------------------------------
-- Instances of register and slot users / definers

instance UserOfRegs LocalReg (CmmNode e x) where
  foldRegsUsed :: DynFlags -> (b -> CmmFormal -> b) -> b -> CmmNode e x -> b
foldRegsUsed dflags :: DynFlags
dflags f :: b -> CmmFormal -> b
f !b
z n :: CmmNode e x
n = case CmmNode e x
n of
    CmmAssign _ expr :: CmmExpr
expr -> (b -> CmmFormal -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z CmmExpr
expr
    CmmStore addr :: CmmExpr
addr rval :: CmmExpr
rval -> (b -> CmmFormal -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f ((b -> CmmFormal -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z CmmExpr
addr) CmmExpr
rval
    CmmUnsafeForeignCall t :: ForeignTarget
t _ args :: [CmmExpr]
args -> (b -> CmmFormal -> b) -> b -> [CmmExpr] -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f ((b -> CmmFormal -> b) -> b -> ForeignTarget -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z ForeignTarget
t) [CmmExpr]
args
    CmmCondBranch expr :: CmmExpr
expr _ _ _ -> (b -> CmmFormal -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z CmmExpr
expr
    CmmSwitch expr :: CmmExpr
expr _ -> (b -> CmmFormal -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z CmmExpr
expr
    CmmCall {cml_target :: CmmNode O C -> CmmExpr
cml_target=CmmExpr
tgt} -> (b -> CmmFormal -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z CmmExpr
tgt
    CmmForeignCall {tgt :: CmmNode O C -> ForeignTarget
tgt=ForeignTarget
tgt, args :: CmmNode O C -> [CmmExpr]
args=[CmmExpr]
args} -> (b -> CmmFormal -> b) -> b -> [CmmExpr] -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f ((b -> CmmFormal -> b) -> b -> ForeignTarget -> b
forall a b.
UserOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z ForeignTarget
tgt) [CmmExpr]
args
    _ -> b
z
    where fold :: forall a b. UserOfRegs LocalReg a
               => (b -> LocalReg -> b) -> b -> a -> b
          fold :: (b -> CmmFormal -> b) -> b -> a -> b
fold f :: b -> CmmFormal -> b
f z :: b
z n :: a
n = DynFlags -> (b -> CmmFormal -> b) -> b -> a -> b
forall r a b.
UserOfRegs r a =>
DynFlags -> (b -> r -> b) -> b -> a -> b
foldRegsUsed DynFlags
dflags b -> CmmFormal -> b
f b
z a
n

instance UserOfRegs GlobalReg (CmmNode e x) where
  foldRegsUsed :: DynFlags -> (b -> GlobalReg -> b) -> b -> CmmNode e x -> b
foldRegsUsed dflags :: DynFlags
dflags f :: b -> GlobalReg -> b
f !b
z n :: CmmNode e x
n = case CmmNode e x
n of
    CmmAssign _ expr :: CmmExpr
expr -> (b -> GlobalReg -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z CmmExpr
expr
    CmmStore addr :: CmmExpr
addr rval :: CmmExpr
rval -> (b -> GlobalReg -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f ((b -> GlobalReg -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z CmmExpr
addr) CmmExpr
rval
    CmmUnsafeForeignCall t :: ForeignTarget
t _ args :: [CmmExpr]
args -> (b -> GlobalReg -> b) -> b -> [CmmExpr] -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f ((b -> GlobalReg -> b) -> b -> ForeignTarget -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z ForeignTarget
t) [CmmExpr]
args
    CmmCondBranch expr :: CmmExpr
expr _ _ _ -> (b -> GlobalReg -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z CmmExpr
expr
    CmmSwitch expr :: CmmExpr
expr _ -> (b -> GlobalReg -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z CmmExpr
expr
    CmmCall {cml_target :: CmmNode O C -> CmmExpr
cml_target=CmmExpr
tgt, cml_args_regs :: CmmNode O C -> [GlobalReg]
cml_args_regs=[GlobalReg]
args} -> (b -> GlobalReg -> b) -> b -> CmmExpr -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f ((b -> GlobalReg -> b) -> b -> [GlobalReg] -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z [GlobalReg]
args) CmmExpr
tgt
    CmmForeignCall {tgt :: CmmNode O C -> ForeignTarget
tgt=ForeignTarget
tgt, args :: CmmNode O C -> [CmmExpr]
args=[CmmExpr]
args} -> (b -> GlobalReg -> b) -> b -> [CmmExpr] -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f ((b -> GlobalReg -> b) -> b -> ForeignTarget -> b
forall a b.
UserOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z ForeignTarget
tgt) [CmmExpr]
args
    _ -> b
z
    where fold :: forall a b.  UserOfRegs GlobalReg a
               => (b -> GlobalReg -> b) -> b -> a -> b
          fold :: (b -> GlobalReg -> b) -> b -> a -> b
fold f :: b -> GlobalReg -> b
f z :: b
z n :: a
n = DynFlags -> (b -> GlobalReg -> b) -> b -> a -> b
forall r a b.
UserOfRegs r a =>
DynFlags -> (b -> r -> b) -> b -> a -> b
foldRegsUsed DynFlags
dflags b -> GlobalReg -> b
f b
z a
n

instance (Ord r, UserOfRegs r CmmReg) => UserOfRegs r ForeignTarget where
  -- The (Ord r) in the context is necessary here
  -- See Note [Recursive superclasses] in TcInstDcls
  foldRegsUsed :: DynFlags -> (b -> r -> b) -> b -> ForeignTarget -> b
foldRegsUsed _      _ !b
z (PrimTarget _)      = b
z
  foldRegsUsed dflags :: DynFlags
dflags f :: b -> r -> b
f !b
z (ForeignTarget e :: CmmExpr
e _) = DynFlags -> (b -> r -> b) -> b -> CmmExpr -> b
forall r a b.
UserOfRegs r a =>
DynFlags -> (b -> r -> b) -> b -> a -> b
foldRegsUsed DynFlags
dflags b -> r -> b
f b
z CmmExpr
e

instance DefinerOfRegs LocalReg (CmmNode e x) where
  foldRegsDefd :: DynFlags -> (b -> CmmFormal -> b) -> b -> CmmNode e x -> b
foldRegsDefd dflags :: DynFlags
dflags f :: b -> CmmFormal -> b
f !b
z n :: CmmNode e x
n = case CmmNode e x
n of
    CmmAssign lhs :: CmmReg
lhs _ -> (b -> CmmFormal -> b) -> b -> CmmReg -> b
forall a b.
DefinerOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z CmmReg
lhs
    CmmUnsafeForeignCall _ fs :: [CmmFormal]
fs _ -> (b -> CmmFormal -> b) -> b -> [CmmFormal] -> b
forall a b.
DefinerOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z [CmmFormal]
fs
    CmmForeignCall {res :: CmmNode O C -> [CmmFormal]
res=[CmmFormal]
res} -> (b -> CmmFormal -> b) -> b -> [CmmFormal] -> b
forall a b.
DefinerOfRegs CmmFormal a =>
(b -> CmmFormal -> b) -> b -> a -> b
fold b -> CmmFormal -> b
f b
z [CmmFormal]
res
    _ -> b
z
    where fold :: forall a b. DefinerOfRegs LocalReg a
               => (b -> LocalReg -> b) -> b -> a -> b
          fold :: (b -> CmmFormal -> b) -> b -> a -> b
fold f :: b -> CmmFormal -> b
f z :: b
z n :: a
n = DynFlags -> (b -> CmmFormal -> b) -> b -> a -> b
forall r a b.
DefinerOfRegs r a =>
DynFlags -> (b -> r -> b) -> b -> a -> b
foldRegsDefd DynFlags
dflags b -> CmmFormal -> b
f b
z a
n

instance DefinerOfRegs GlobalReg (CmmNode e x) where
  foldRegsDefd :: DynFlags -> (b -> GlobalReg -> b) -> b -> CmmNode e x -> b
foldRegsDefd dflags :: DynFlags
dflags f :: b -> GlobalReg -> b
f !b
z n :: CmmNode e x
n = case CmmNode e x
n of
    CmmAssign lhs :: CmmReg
lhs _ -> (b -> GlobalReg -> b) -> b -> CmmReg -> b
forall a b.
DefinerOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z CmmReg
lhs
    CmmUnsafeForeignCall tgt :: ForeignTarget
tgt _ _  -> (b -> GlobalReg -> b) -> b -> [GlobalReg] -> b
forall a b.
DefinerOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z (ForeignTarget -> [GlobalReg]
foreignTargetRegs ForeignTarget
tgt)
    CmmCall        {} -> (b -> GlobalReg -> b) -> b -> [GlobalReg] -> b
forall a b.
DefinerOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z [GlobalReg]
activeRegs
    CmmForeignCall {} -> (b -> GlobalReg -> b) -> b -> [GlobalReg] -> b
forall a b.
DefinerOfRegs GlobalReg a =>
(b -> GlobalReg -> b) -> b -> a -> b
fold b -> GlobalReg -> b
f b
z [GlobalReg]
activeRegs
                      -- See Note [Safe foreign calls clobber STG registers]
    _ -> b
z
    where fold :: forall a b. DefinerOfRegs GlobalReg a
               => (b -> GlobalReg -> b) -> b -> a -> b
          fold :: (b -> GlobalReg -> b) -> b -> a -> b
fold f :: b -> GlobalReg -> b
f z :: b
z n :: a
n = DynFlags -> (b -> GlobalReg -> b) -> b -> a -> b
forall r a b.
DefinerOfRegs r a =>
DynFlags -> (b -> r -> b) -> b -> a -> b
foldRegsDefd DynFlags
dflags b -> GlobalReg -> b
f b
z a
n

          platform :: Platform
platform = DynFlags -> Platform
targetPlatform DynFlags
dflags
          activeRegs :: [GlobalReg]
activeRegs = Platform -> [GlobalReg]
activeStgRegs Platform
platform
          activeCallerSavesRegs :: [GlobalReg]
activeCallerSavesRegs = (GlobalReg -> Bool) -> [GlobalReg] -> [GlobalReg]
forall a. (a -> Bool) -> [a] -> [a]
filter (Platform -> GlobalReg -> Bool
callerSaves Platform
platform) [GlobalReg]
activeRegs

          foreignTargetRegs :: ForeignTarget -> [GlobalReg]
foreignTargetRegs (ForeignTarget _ (ForeignConvention _ _ _ CmmNeverReturns)) = []
          foreignTargetRegs _ = [GlobalReg]
activeCallerSavesRegs

-- Note [Safe foreign calls clobber STG registers]
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
-- During stack layout phase every safe foreign call is expanded into a block
-- that contains unsafe foreign call (instead of safe foreign call) and ends
-- with a normal call (See Note [Foreign calls]). This means that we must
-- treat safe foreign call as if it was a normal call (because eventually it
-- will be). This is important if we try to run sinking pass before stack
-- layout phase. Consider this example of what might go wrong (this is cmm
-- code from stablename001 test). Here is code after common block elimination
-- (before stack layout):
--
--  c1q6:
--      _s1pf::P64 = R1;
--      _c1q8::I64 = performMajorGC;
--      I64[(young<c1q9> + 8)] = c1q9;
--      foreign call "ccall" arg hints:  []  result hints:  [] (_c1q8::I64)(...)
--                   returns to c1q9 args: ([]) ress: ([])ret_args: 8ret_off: 8;
--  c1q9:
--      I64[(young<c1qb> + 8)] = c1qb;
--      R1 = _s1pc::P64;
--      call stg_makeStableName#(R1) returns to c1qb, args: 8, res: 8, upd: 8;
--
-- If we run sinking pass now (still before stack layout) we will get this:
--
--  c1q6:
--      I64[(young<c1q9> + 8)] = c1q9;
--      foreign call "ccall" arg hints:  []  result hints:  [] performMajorGC(...)
--                   returns to c1q9 args: ([]) ress: ([])ret_args: 8ret_off: 8;
--  c1q9:
--      I64[(young<c1qb> + 8)] = c1qb;
--      _s1pf::P64 = R1;         <------ _s1pf sunk past safe foreign call
--      R1 = _s1pc::P64;
--      call stg_makeStableName#(R1) returns to c1qb, args: 8, res: 8, upd: 8;
--
-- Notice that _s1pf was sunk past a foreign call. When we run stack layout
-- safe call to performMajorGC will be turned into:
--
--  c1q6:
--      _s1pc::P64 = P64[Sp + 8];
--      I64[Sp - 8] = c1q9;
--      Sp = Sp - 8;
--      I64[I64[CurrentTSO + 24] + 16] = Sp;
--      P64[CurrentNursery + 8] = Hp + 8;
--      (_u1qI::I64) = call "ccall" arg hints:  [PtrHint,]
--                           result hints:  [PtrHint] suspendThread(BaseReg, 0);
--      call "ccall" arg hints:  []  result hints:  [] performMajorGC();
--      (_u1qJ::I64) = call "ccall" arg hints:  [PtrHint]
--                           result hints:  [PtrHint] resumeThread(_u1qI::I64);
--      BaseReg = _u1qJ::I64;
--      _u1qK::P64 = CurrentTSO;
--      _u1qL::P64 = I64[_u1qK::P64 + 24];
--      Sp = I64[_u1qL::P64 + 16];
--      SpLim = _u1qL::P64 + 192;
--      HpAlloc = 0;
--      Hp = I64[CurrentNursery + 8] - 8;
--      HpLim = I64[CurrentNursery] + (%MO_SS_Conv_W32_W64(I32[CurrentNursery + 48]) * 4096 - 1);
--      call (I64[Sp])() returns to c1q9, args: 8, res: 8, upd: 8;
--  c1q9:
--      I64[(young<c1qb> + 8)] = c1qb;
--      _s1pf::P64 = R1;         <------ INCORRECT!
--      R1 = _s1pc::P64;
--      call stg_makeStableName#(R1) returns to c1qb, args: 8, res: 8, upd: 8;
--
-- Notice that c1q6 now ends with a call. Sinking _s1pf::P64 = R1 past that
-- call is clearly incorrect. This is what would happen if we assumed that
-- safe foreign call has the same semantics as unsafe foreign call. To prevent
-- this we need to treat safe foreign call as if was normal call.

-----------------------------------
-- mapping Expr in CmmNode

mapForeignTarget :: (CmmExpr -> CmmExpr) -> ForeignTarget -> ForeignTarget
mapForeignTarget :: (CmmExpr -> CmmExpr) -> ForeignTarget -> ForeignTarget
mapForeignTarget exp :: CmmExpr -> CmmExpr
exp   (ForeignTarget e :: CmmExpr
e c :: ForeignConvention
c) = CmmExpr -> ForeignConvention -> ForeignTarget
ForeignTarget (CmmExpr -> CmmExpr
exp CmmExpr
e) ForeignConvention
c
mapForeignTarget _   m :: ForeignTarget
m@(PrimTarget _)      = ForeignTarget
m

wrapRecExp :: (CmmExpr -> CmmExpr) -> CmmExpr -> CmmExpr
-- Take a transformer on expressions and apply it recursively.
-- (wrapRecExp f e) first recursively applies itself to sub-expressions of e
--                  then  uses f to rewrite the resulting expression
wrapRecExp :: (CmmExpr -> CmmExpr) -> CmmExpr -> CmmExpr
wrapRecExp f :: CmmExpr -> CmmExpr
f (CmmMachOp op :: MachOp
op es :: [CmmExpr]
es)    = CmmExpr -> CmmExpr
f (MachOp -> [CmmExpr] -> CmmExpr
CmmMachOp MachOp
op ([CmmExpr] -> CmmExpr) -> [CmmExpr] -> CmmExpr
forall a b. (a -> b) -> a -> b
$ (CmmExpr -> CmmExpr) -> [CmmExpr] -> [CmmExpr]
forall a b. (a -> b) -> [a] -> [b]
map ((CmmExpr -> CmmExpr) -> CmmExpr -> CmmExpr
wrapRecExp CmmExpr -> CmmExpr
f) [CmmExpr]
es)
wrapRecExp f :: CmmExpr -> CmmExpr
f (CmmLoad addr :: CmmExpr
addr ty :: CmmType
ty)    = CmmExpr -> CmmExpr
f (CmmExpr -> CmmType -> CmmExpr
CmmLoad ((CmmExpr -> CmmExpr) -> CmmExpr -> CmmExpr
wrapRecExp CmmExpr -> CmmExpr
f CmmExpr
addr) CmmType
ty)
wrapRecExp f :: CmmExpr -> CmmExpr
f e :: CmmExpr
e                    = CmmExpr -> CmmExpr
f CmmExpr
e

mapExp :: (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExp :: (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExp _ f :: CmmNode e x
f@(CmmEntry{})                          = CmmNode e x
f
mapExp _ m :: CmmNode e x
m@(CmmComment _)                        = CmmNode e x
m
mapExp _ m :: CmmNode e x
m@(CmmTick _)                           = CmmNode e x
m
mapExp f :: CmmExpr -> CmmExpr
f   (CmmUnwind regs :: [(GlobalReg, Maybe CmmExpr)]
regs)                      = [(GlobalReg, Maybe CmmExpr)] -> CmmNode O O
CmmUnwind (((GlobalReg, Maybe CmmExpr) -> (GlobalReg, Maybe CmmExpr))
-> [(GlobalReg, Maybe CmmExpr)] -> [(GlobalReg, Maybe CmmExpr)]
forall a b. (a -> b) -> [a] -> [b]
map ((Maybe CmmExpr -> Maybe CmmExpr)
-> (GlobalReg, Maybe CmmExpr) -> (GlobalReg, Maybe CmmExpr)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap ((CmmExpr -> CmmExpr) -> Maybe CmmExpr -> Maybe CmmExpr
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap CmmExpr -> CmmExpr
f)) [(GlobalReg, Maybe CmmExpr)]
regs)
mapExp f :: CmmExpr -> CmmExpr
f   (CmmAssign r :: CmmReg
r e :: CmmExpr
e)                       = CmmReg -> CmmExpr -> CmmNode O O
CmmAssign CmmReg
r (CmmExpr -> CmmExpr
f CmmExpr
e)
mapExp f :: CmmExpr -> CmmExpr
f   (CmmStore addr :: CmmExpr
addr e :: CmmExpr
e)                     = CmmExpr -> CmmExpr -> CmmNode O O
CmmStore (CmmExpr -> CmmExpr
f CmmExpr
addr) (CmmExpr -> CmmExpr
f CmmExpr
e)
mapExp f :: CmmExpr -> CmmExpr
f   (CmmUnsafeForeignCall tgt :: ForeignTarget
tgt fs :: [CmmFormal]
fs as :: [CmmExpr]
as)      = ForeignTarget -> [CmmFormal] -> [CmmExpr] -> CmmNode O O
CmmUnsafeForeignCall ((CmmExpr -> CmmExpr) -> ForeignTarget -> ForeignTarget
mapForeignTarget CmmExpr -> CmmExpr
f ForeignTarget
tgt) [CmmFormal]
fs ((CmmExpr -> CmmExpr) -> [CmmExpr] -> [CmmExpr]
forall a b. (a -> b) -> [a] -> [b]
map CmmExpr -> CmmExpr
f [CmmExpr]
as)
mapExp _ l :: CmmNode e x
l@(CmmBranch _)                         = CmmNode e x
l
mapExp f :: CmmExpr -> CmmExpr
f   (CmmCondBranch e :: CmmExpr
e ti :: Label
ti fi :: Label
fi l :: Maybe Bool
l)             = CmmExpr -> Label -> Label -> Maybe Bool -> CmmNode O C
CmmCondBranch (CmmExpr -> CmmExpr
f CmmExpr
e) Label
ti Label
fi Maybe Bool
l
mapExp f :: CmmExpr -> CmmExpr
f   (CmmSwitch e :: CmmExpr
e ids :: SwitchTargets
ids)                     = CmmExpr -> SwitchTargets -> CmmNode O C
CmmSwitch (CmmExpr -> CmmExpr
f CmmExpr
e) SwitchTargets
ids
mapExp f :: CmmExpr -> CmmExpr
f   n :: CmmNode e x
n@CmmCall {cml_target :: CmmNode O C -> CmmExpr
cml_target=CmmExpr
tgt}            = CmmNode e x
n{cml_target :: CmmExpr
cml_target = CmmExpr -> CmmExpr
f CmmExpr
tgt}
mapExp f :: CmmExpr -> CmmExpr
f   (CmmForeignCall tgt :: ForeignTarget
tgt fs :: [CmmFormal]
fs as :: [CmmExpr]
as succ :: Label
succ ret_args :: ByteOff
ret_args updfr :: ByteOff
updfr intrbl :: Bool
intrbl) = ForeignTarget
-> [CmmFormal]
-> [CmmExpr]
-> Label
-> ByteOff
-> ByteOff
-> Bool
-> CmmNode O C
CmmForeignCall ((CmmExpr -> CmmExpr) -> ForeignTarget -> ForeignTarget
mapForeignTarget CmmExpr -> CmmExpr
f ForeignTarget
tgt) [CmmFormal]
fs ((CmmExpr -> CmmExpr) -> [CmmExpr] -> [CmmExpr]
forall a b. (a -> b) -> [a] -> [b]
map CmmExpr -> CmmExpr
f [CmmExpr]
as) Label
succ ByteOff
ret_args ByteOff
updfr Bool
intrbl

mapExpDeep :: (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExpDeep :: (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExpDeep f :: CmmExpr -> CmmExpr
f = (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
forall e x. (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
mapExp ((CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x)
-> (CmmExpr -> CmmExpr) -> CmmNode e x -> CmmNode e x
forall a b. (a -> b) -> a -> b
$ (CmmExpr -> CmmExpr) -> CmmExpr -> CmmExpr
wrapRecExp CmmExpr -> CmmExpr
f

------------------------------------------------------------------------
-- mapping Expr in CmmNode, but not performing allocation if no changes

mapForeignTargetM :: (CmmExpr -> Maybe CmmExpr) -> ForeignTarget -> Maybe ForeignTarget
mapForeignTargetM :: (CmmExpr -> Maybe CmmExpr) -> ForeignTarget -> Maybe ForeignTarget
mapForeignTargetM f :: CmmExpr -> Maybe CmmExpr
f (ForeignTarget e :: CmmExpr
e c :: ForeignConvention
c) = (\x :: CmmExpr
x -> CmmExpr -> ForeignConvention -> ForeignTarget
ForeignTarget CmmExpr
x ForeignConvention
c) (CmmExpr -> ForeignTarget) -> Maybe CmmExpr -> Maybe ForeignTarget
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CmmExpr -> Maybe CmmExpr
f CmmExpr
e
mapForeignTargetM _ (PrimTarget _)      = Maybe ForeignTarget
forall a. Maybe a
Nothing

wrapRecExpM :: (CmmExpr -> Maybe CmmExpr) -> (CmmExpr -> Maybe CmmExpr)
-- (wrapRecExpM f e) first recursively applies itself to sub-expressions of e
--                   then  gives f a chance to rewrite the resulting expression
wrapRecExpM :: (CmmExpr -> Maybe CmmExpr) -> CmmExpr -> Maybe CmmExpr
wrapRecExpM f :: CmmExpr -> Maybe CmmExpr
f n :: CmmExpr
n@(CmmMachOp op :: MachOp
op es :: [CmmExpr]
es)  = Maybe CmmExpr
-> ([CmmExpr] -> Maybe CmmExpr) -> Maybe [CmmExpr] -> Maybe CmmExpr
forall b a. b -> (a -> b) -> Maybe a -> b
maybe (CmmExpr -> Maybe CmmExpr
f CmmExpr
n) (CmmExpr -> Maybe CmmExpr
f (CmmExpr -> Maybe CmmExpr)
-> ([CmmExpr] -> CmmExpr) -> [CmmExpr] -> Maybe CmmExpr
forall b c a. (b -> c) -> (a -> b) -> a -> c
. MachOp -> [CmmExpr] -> CmmExpr
CmmMachOp MachOp
op)    ((CmmExpr -> Maybe CmmExpr) -> [CmmExpr] -> Maybe [CmmExpr]
forall a. (a -> Maybe a) -> [a] -> Maybe [a]
mapListM ((CmmExpr -> Maybe CmmExpr) -> CmmExpr -> Maybe CmmExpr
wrapRecExpM CmmExpr -> Maybe CmmExpr
f) [CmmExpr]
es)
wrapRecExpM f :: CmmExpr -> Maybe CmmExpr
f n :: CmmExpr
n@(CmmLoad addr :: CmmExpr
addr ty :: CmmType
ty)  = Maybe CmmExpr
-> (CmmExpr -> Maybe CmmExpr) -> Maybe CmmExpr -> Maybe CmmExpr
forall b a. b -> (a -> b) -> Maybe a -> b
maybe (CmmExpr -> Maybe CmmExpr
f CmmExpr
n) (CmmExpr -> Maybe CmmExpr
f (CmmExpr -> Maybe CmmExpr)
-> (CmmExpr -> CmmExpr) -> CmmExpr -> Maybe CmmExpr
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (CmmExpr -> CmmType -> CmmExpr) -> CmmType -> CmmExpr -> CmmExpr
forall a b c. (a -> b -> c) -> b -> a -> c
flip CmmExpr -> CmmType -> CmmExpr
CmmLoad CmmType
ty) ((CmmExpr -> Maybe CmmExpr) -> CmmExpr -> Maybe CmmExpr
wrapRecExpM CmmExpr -> Maybe CmmExpr
f CmmExpr
addr)
wrapRecExpM f :: CmmExpr -> Maybe CmmExpr
f e :: CmmExpr
e                    = CmmExpr -> Maybe CmmExpr
f CmmExpr
e

mapExpM :: (CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
mapExpM :: (CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
mapExpM _ (CmmEntry{})              = Maybe (CmmNode e x)
forall a. Maybe a
Nothing
mapExpM _ (CmmComment _)            = Maybe (CmmNode e x)
forall a. Maybe a
Nothing
mapExpM _ (CmmTick _)               = Maybe (CmmNode e x)
forall a. Maybe a
Nothing
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmUnwind regs :: [(GlobalReg, Maybe CmmExpr)]
regs)          = [(GlobalReg, Maybe CmmExpr)] -> CmmNode O O
CmmUnwind ([(GlobalReg, Maybe CmmExpr)] -> CmmNode O O)
-> Maybe [(GlobalReg, Maybe CmmExpr)] -> Maybe (CmmNode O O)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` ((GlobalReg, Maybe CmmExpr) -> Maybe (GlobalReg, Maybe CmmExpr))
-> [(GlobalReg, Maybe CmmExpr)]
-> Maybe [(GlobalReg, Maybe CmmExpr)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (\(r :: GlobalReg
r,e :: Maybe CmmExpr
e) -> (CmmExpr -> Maybe CmmExpr)
-> Maybe CmmExpr -> Maybe (Maybe CmmExpr)
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM CmmExpr -> Maybe CmmExpr
f Maybe CmmExpr
e Maybe (Maybe CmmExpr)
-> (Maybe CmmExpr -> Maybe (GlobalReg, Maybe CmmExpr))
-> Maybe (GlobalReg, Maybe CmmExpr)
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= \e' :: Maybe CmmExpr
e' -> (GlobalReg, Maybe CmmExpr) -> Maybe (GlobalReg, Maybe CmmExpr)
forall (f :: * -> *) a. Applicative f => a -> f a
pure (GlobalReg
r,Maybe CmmExpr
e')) [(GlobalReg, Maybe CmmExpr)]
regs
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmAssign r :: CmmReg
r e :: CmmExpr
e)           = CmmReg -> CmmExpr -> CmmNode O O
CmmAssign CmmReg
r (CmmExpr -> CmmNode O O) -> Maybe CmmExpr -> Maybe (CmmNode O O)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CmmExpr -> Maybe CmmExpr
f CmmExpr
e
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmStore addr :: CmmExpr
addr e :: CmmExpr
e)         = (\[addr' :: CmmExpr
addr', e' :: CmmExpr
e'] -> CmmExpr -> CmmExpr -> CmmNode O O
CmmStore CmmExpr
addr' CmmExpr
e') ([CmmExpr] -> CmmNode O O)
-> Maybe [CmmExpr] -> Maybe (CmmNode O O)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` (CmmExpr -> Maybe CmmExpr) -> [CmmExpr] -> Maybe [CmmExpr]
forall a. (a -> Maybe a) -> [a] -> Maybe [a]
mapListM CmmExpr -> Maybe CmmExpr
f [CmmExpr
addr, CmmExpr
e]
mapExpM _ (CmmBranch _)             = Maybe (CmmNode e x)
forall a. Maybe a
Nothing
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmCondBranch e :: CmmExpr
e ti :: Label
ti fi :: Label
fi l :: Maybe Bool
l) = (\x :: CmmExpr
x -> CmmExpr -> Label -> Label -> Maybe Bool -> CmmNode O C
CmmCondBranch CmmExpr
x Label
ti Label
fi Maybe Bool
l) (CmmExpr -> CmmNode O C) -> Maybe CmmExpr -> Maybe (CmmNode O C)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CmmExpr -> Maybe CmmExpr
f CmmExpr
e
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmSwitch e :: CmmExpr
e tbl :: SwitchTargets
tbl)         = (\x :: CmmExpr
x -> CmmExpr -> SwitchTargets -> CmmNode O C
CmmSwitch CmmExpr
x SwitchTargets
tbl)       (CmmExpr -> CmmNode O C) -> Maybe CmmExpr -> Maybe (CmmNode O C)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CmmExpr -> Maybe CmmExpr
f CmmExpr
e
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmCall tgt :: CmmExpr
tgt mb_id :: Maybe Label
mb_id r :: [GlobalReg]
r o :: ByteOff
o i :: ByteOff
i s :: ByteOff
s) = (\x :: CmmExpr
x -> CmmExpr
-> Maybe Label
-> [GlobalReg]
-> ByteOff
-> ByteOff
-> ByteOff
-> CmmNode O C
CmmCall CmmExpr
x Maybe Label
mb_id [GlobalReg]
r ByteOff
o ByteOff
i ByteOff
s) (CmmExpr -> CmmNode O C) -> Maybe CmmExpr -> Maybe (CmmNode O C)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` CmmExpr -> Maybe CmmExpr
f CmmExpr
tgt
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmUnsafeForeignCall tgt :: ForeignTarget
tgt fs :: [CmmFormal]
fs as :: [CmmExpr]
as)
    = case (CmmExpr -> Maybe CmmExpr) -> ForeignTarget -> Maybe ForeignTarget
mapForeignTargetM CmmExpr -> Maybe CmmExpr
f ForeignTarget
tgt of
        Just tgt' :: ForeignTarget
tgt' -> CmmNode O O -> Maybe (CmmNode O O)
forall a. a -> Maybe a
Just (ForeignTarget -> [CmmFormal] -> [CmmExpr] -> CmmNode O O
CmmUnsafeForeignCall ForeignTarget
tgt' [CmmFormal]
fs ((CmmExpr -> Maybe CmmExpr) -> [CmmExpr] -> [CmmExpr]
forall a. (a -> Maybe a) -> [a] -> [a]
mapListJ CmmExpr -> Maybe CmmExpr
f [CmmExpr]
as))
        Nothing   -> (\xs :: [CmmExpr]
xs -> ForeignTarget -> [CmmFormal] -> [CmmExpr] -> CmmNode O O
CmmUnsafeForeignCall ForeignTarget
tgt [CmmFormal]
fs [CmmExpr]
xs) ([CmmExpr] -> CmmNode O O)
-> Maybe [CmmExpr] -> Maybe (CmmNode O O)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` (CmmExpr -> Maybe CmmExpr) -> [CmmExpr] -> Maybe [CmmExpr]
forall a. (a -> Maybe a) -> [a] -> Maybe [a]
mapListM CmmExpr -> Maybe CmmExpr
f [CmmExpr]
as
mapExpM f :: CmmExpr -> Maybe CmmExpr
f (CmmForeignCall tgt :: ForeignTarget
tgt fs :: [CmmFormal]
fs as :: [CmmExpr]
as succ :: Label
succ ret_args :: ByteOff
ret_args updfr :: ByteOff
updfr intrbl :: Bool
intrbl)
    = case (CmmExpr -> Maybe CmmExpr) -> ForeignTarget -> Maybe ForeignTarget
mapForeignTargetM CmmExpr -> Maybe CmmExpr
f ForeignTarget
tgt of
        Just tgt' :: ForeignTarget
tgt' -> CmmNode O C -> Maybe (CmmNode O C)
forall a. a -> Maybe a
Just (ForeignTarget
-> [CmmFormal]
-> [CmmExpr]
-> Label
-> ByteOff
-> ByteOff
-> Bool
-> CmmNode O C
CmmForeignCall ForeignTarget
tgt' [CmmFormal]
fs ((CmmExpr -> Maybe CmmExpr) -> [CmmExpr] -> [CmmExpr]
forall a. (a -> Maybe a) -> [a] -> [a]
mapListJ CmmExpr -> Maybe CmmExpr
f [CmmExpr]
as) Label
succ ByteOff
ret_args ByteOff
updfr Bool
intrbl)
        Nothing   -> (\xs :: [CmmExpr]
xs -> ForeignTarget
-> [CmmFormal]
-> [CmmExpr]
-> Label
-> ByteOff
-> ByteOff
-> Bool
-> CmmNode O C
CmmForeignCall ForeignTarget
tgt [CmmFormal]
fs [CmmExpr]
xs Label
succ ByteOff
ret_args ByteOff
updfr Bool
intrbl) ([CmmExpr] -> CmmNode O C)
-> Maybe [CmmExpr] -> Maybe (CmmNode O C)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
`fmap` (CmmExpr -> Maybe CmmExpr) -> [CmmExpr] -> Maybe [CmmExpr]
forall a. (a -> Maybe a) -> [a] -> Maybe [a]
mapListM CmmExpr -> Maybe CmmExpr
f [CmmExpr]
as

-- share as much as possible
mapListM :: (a -> Maybe a) -> [a] -> Maybe [a]
mapListM :: (a -> Maybe a) -> [a] -> Maybe [a]
mapListM f :: a -> Maybe a
f xs :: [a]
xs = let (b :: Bool
b, r :: [a]
r) = (a -> Maybe a) -> [a] -> (Bool, [a])
forall a. (a -> Maybe a) -> [a] -> (Bool, [a])
mapListT a -> Maybe a
f [a]
xs
                in if Bool
b then [a] -> Maybe [a]
forall a. a -> Maybe a
Just [a]
r else Maybe [a]
forall a. Maybe a
Nothing

mapListJ :: (a -> Maybe a) -> [a] -> [a]
mapListJ :: (a -> Maybe a) -> [a] -> [a]
mapListJ f :: a -> Maybe a
f xs :: [a]
xs = (Bool, [a]) -> [a]
forall a b. (a, b) -> b
snd ((a -> Maybe a) -> [a] -> (Bool, [a])
forall a. (a -> Maybe a) -> [a] -> (Bool, [a])
mapListT a -> Maybe a
f [a]
xs)

mapListT :: (a -> Maybe a) -> [a] -> (Bool, [a])
mapListT :: (a -> Maybe a) -> [a] -> (Bool, [a])
mapListT f :: a -> Maybe a
f xs :: [a]
xs = (([a], a, Maybe a) -> (Bool, [a]) -> (Bool, [a]))
-> (Bool, [a]) -> [([a], a, Maybe a)] -> (Bool, [a])
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr ([a], a, Maybe a) -> (Bool, [a]) -> (Bool, [a])
forall a. ([a], a, Maybe a) -> (Bool, [a]) -> (Bool, [a])
g (Bool
False, []) ([[a]] -> [a] -> [Maybe a] -> [([a], a, Maybe a)]
forall a b c. [a] -> [b] -> [c] -> [(a, b, c)]
zip3 ([a] -> [[a]]
forall a. [a] -> [[a]]
tails [a]
xs) [a]
xs ((a -> Maybe a) -> [a] -> [Maybe a]
forall a b. (a -> b) -> [a] -> [b]
map a -> Maybe a
f [a]
xs))
    where g :: ([a], a, Maybe a) -> (Bool, [a]) -> (Bool, [a])
g (_,   y :: a
y, Nothing) (True, ys :: [a]
ys)  = (Bool
True,  a
ya -> [a] -> [a]
forall a. a -> [a] -> [a]
:[a]
ys)
          g (_,   _, Just y :: a
y)  (True, ys :: [a]
ys)  = (Bool
True,  a
ya -> [a] -> [a]
forall a. a -> [a] -> [a]
:[a]
ys)
          g (ys' :: [a]
ys', _, Nothing) (False, _)  = (Bool
False, [a]
ys')
          g (_,   _, Just y :: a
y)  (False, ys :: [a]
ys) = (Bool
True,  a
ya -> [a] -> [a]
forall a. a -> [a] -> [a]
:[a]
ys)

mapExpDeepM :: (CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
mapExpDeepM :: (CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
mapExpDeepM f :: CmmExpr -> Maybe CmmExpr
f = (CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
forall e x.
(CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
mapExpM ((CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x))
-> (CmmExpr -> Maybe CmmExpr) -> CmmNode e x -> Maybe (CmmNode e x)
forall a b. (a -> b) -> a -> b
$ (CmmExpr -> Maybe CmmExpr) -> CmmExpr -> Maybe CmmExpr
wrapRecExpM CmmExpr -> Maybe CmmExpr
f

-----------------------------------
-- folding Expr in CmmNode

foldExpForeignTarget :: (CmmExpr -> z -> z) -> ForeignTarget -> z -> z
foldExpForeignTarget :: (CmmExpr -> z -> z) -> ForeignTarget -> z -> z
foldExpForeignTarget exp :: CmmExpr -> z -> z
exp (ForeignTarget e :: CmmExpr
e _) z :: z
z = CmmExpr -> z -> z
exp CmmExpr
e z
z
foldExpForeignTarget _   (PrimTarget _)      z :: z
z = z
z

-- Take a folder on expressions and apply it recursively.
-- Specifically (wrapRecExpf f e z) deals with CmmMachOp and CmmLoad
-- itself, delegating all the other CmmExpr forms to 'f'.
wrapRecExpf :: (CmmExpr -> z -> z) -> CmmExpr -> z -> z
wrapRecExpf :: (CmmExpr -> z -> z) -> CmmExpr -> z -> z
wrapRecExpf f :: CmmExpr -> z -> z
f e :: CmmExpr
e@(CmmMachOp _ es :: [CmmExpr]
es) z :: z
z = (CmmExpr -> z -> z) -> z -> [CmmExpr] -> z
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr ((CmmExpr -> z -> z) -> CmmExpr -> z -> z
forall z. (CmmExpr -> z -> z) -> CmmExpr -> z -> z
wrapRecExpf CmmExpr -> z -> z
f) (CmmExpr -> z -> z
f CmmExpr
e z
z) [CmmExpr]
es
wrapRecExpf f :: CmmExpr -> z -> z
f e :: CmmExpr
e@(CmmLoad addr :: CmmExpr
addr _) z :: z
z = (CmmExpr -> z -> z) -> CmmExpr -> z -> z
forall z. (CmmExpr -> z -> z) -> CmmExpr -> z -> z
wrapRecExpf CmmExpr -> z -> z
f CmmExpr
addr (CmmExpr -> z -> z
f CmmExpr
e z
z)
wrapRecExpf f :: CmmExpr -> z -> z
f e :: CmmExpr
e                  z :: z
z = CmmExpr -> z -> z
f CmmExpr
e z
z

foldExp :: (CmmExpr -> z -> z) -> CmmNode e x -> z -> z
foldExp :: (CmmExpr -> z -> z) -> CmmNode e x -> z -> z
foldExp _ (CmmEntry {}) z :: z
z                         = z
z
foldExp _ (CmmComment {}) z :: z
z                       = z
z
foldExp _ (CmmTick {}) z :: z
z                          = z
z
foldExp f :: CmmExpr -> z -> z
f (CmmUnwind xs :: [(GlobalReg, Maybe CmmExpr)]
xs) z :: z
z                        = (Maybe CmmExpr -> z -> z) -> z -> [Maybe CmmExpr] -> z
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr ((z -> z) -> (CmmExpr -> z -> z) -> Maybe CmmExpr -> z -> z
forall b a. b -> (a -> b) -> Maybe a -> b
maybe z -> z
forall a. a -> a
id CmmExpr -> z -> z
f) z
z (((GlobalReg, Maybe CmmExpr) -> Maybe CmmExpr)
-> [(GlobalReg, Maybe CmmExpr)] -> [Maybe CmmExpr]
forall a b. (a -> b) -> [a] -> [b]
map (GlobalReg, Maybe CmmExpr) -> Maybe CmmExpr
forall a b. (a, b) -> b
snd [(GlobalReg, Maybe CmmExpr)]
xs)
foldExp f :: CmmExpr -> z -> z
f (CmmAssign _ e :: CmmExpr
e) z :: z
z                       = CmmExpr -> z -> z
f CmmExpr
e z
z
foldExp f :: CmmExpr -> z -> z
f (CmmStore addr :: CmmExpr
addr e :: CmmExpr
e) z :: z
z                     = CmmExpr -> z -> z
f CmmExpr
addr (z -> z) -> z -> z
forall a b. (a -> b) -> a -> b
$ CmmExpr -> z -> z
f CmmExpr
e z
z
foldExp f :: CmmExpr -> z -> z
f (CmmUnsafeForeignCall t :: ForeignTarget
t _ as :: [CmmExpr]
as) z :: z
z         = (CmmExpr -> z -> z) -> z -> [CmmExpr] -> z
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr CmmExpr -> z -> z
f ((CmmExpr -> z -> z) -> ForeignTarget -> z -> z
forall z. (CmmExpr -> z -> z) -> ForeignTarget -> z -> z
foldExpForeignTarget CmmExpr -> z -> z
f ForeignTarget
t z
z) [CmmExpr]
as
foldExp _ (CmmBranch _) z :: z
z                         = z
z
foldExp f :: CmmExpr -> z -> z
f (CmmCondBranch e :: CmmExpr
e _ _ _) z :: z
z               = CmmExpr -> z -> z
f CmmExpr
e z
z
foldExp f :: CmmExpr -> z -> z
f (CmmSwitch e :: CmmExpr
e _) z :: z
z                       = CmmExpr -> z -> z
f CmmExpr
e z
z
foldExp f :: CmmExpr -> z -> z
f (CmmCall {cml_target :: CmmNode O C -> CmmExpr
cml_target=CmmExpr
tgt}) z :: z
z            = CmmExpr -> z -> z
f CmmExpr
tgt z
z
foldExp f :: CmmExpr -> z -> z
f (CmmForeignCall {tgt :: CmmNode O C -> ForeignTarget
tgt=ForeignTarget
tgt, args :: CmmNode O C -> [CmmExpr]
args=[CmmExpr]
args}) z :: z
z = (CmmExpr -> z -> z) -> z -> [CmmExpr] -> z
forall (t :: * -> *) a b.
Foldable t =>
(a -> b -> b) -> b -> t a -> b
foldr CmmExpr -> z -> z
f ((CmmExpr -> z -> z) -> ForeignTarget -> z -> z
forall z. (CmmExpr -> z -> z) -> ForeignTarget -> z -> z
foldExpForeignTarget CmmExpr -> z -> z
f ForeignTarget
tgt z
z) [CmmExpr]
args

foldExpDeep :: (CmmExpr -> z -> z) -> CmmNode e x -> z -> z
foldExpDeep :: (CmmExpr -> z -> z) -> CmmNode e x -> z -> z
foldExpDeep f :: CmmExpr -> z -> z
f = (CmmExpr -> z -> z) -> CmmNode e x -> z -> z
forall z e x. (CmmExpr -> z -> z) -> CmmNode e x -> z -> z
foldExp ((CmmExpr -> z -> z) -> CmmExpr -> z -> z
forall z. (CmmExpr -> z -> z) -> CmmExpr -> z -> z
wrapRecExpf CmmExpr -> z -> z
f)

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

mapSuccessors :: (Label -> Label) -> CmmNode O C -> CmmNode O C
mapSuccessors :: (Label -> Label) -> CmmNode O C -> CmmNode O C
mapSuccessors f :: Label -> Label
f (CmmBranch bid :: Label
bid)         = Label -> CmmNode O C
CmmBranch (Label -> Label
f Label
bid)
mapSuccessors f :: Label -> Label
f (CmmCondBranch p :: CmmExpr
p y :: Label
y n :: Label
n l :: Maybe Bool
l) = CmmExpr -> Label -> Label -> Maybe Bool -> CmmNode O C
CmmCondBranch CmmExpr
p (Label -> Label
f Label
y) (Label -> Label
f Label
n) Maybe Bool
l
mapSuccessors f :: Label -> Label
f (CmmSwitch e :: CmmExpr
e ids :: SwitchTargets
ids)       = CmmExpr -> SwitchTargets -> CmmNode O C
CmmSwitch CmmExpr
e ((Label -> Label) -> SwitchTargets -> SwitchTargets
mapSwitchTargets Label -> Label
f SwitchTargets
ids)
mapSuccessors _ n :: CmmNode O C
n = CmmNode O C
n

mapCollectSuccessors :: forall a. (Label -> (Label,a)) -> CmmNode O C
                     -> (CmmNode O C, [a])
mapCollectSuccessors :: (Label -> (Label, a)) -> CmmNode O C -> (CmmNode O C, [a])
mapCollectSuccessors f :: Label -> (Label, a)
f (CmmBranch bid :: Label
bid)
  = let (bid' :: Label
bid', acc :: a
acc) = Label -> (Label, a)
f Label
bid in (Label -> CmmNode O C
CmmBranch Label
bid', [a
acc])
mapCollectSuccessors f :: Label -> (Label, a)
f (CmmCondBranch p :: CmmExpr
p y :: Label
y n :: Label
n l :: Maybe Bool
l)
  = let (bidt :: Label
bidt, acct :: a
acct) = Label -> (Label, a)
f Label
y
        (bidf :: Label
bidf, accf :: a
accf) = Label -> (Label, a)
f Label
n
    in  (CmmExpr -> Label -> Label -> Maybe Bool -> CmmNode O C
CmmCondBranch CmmExpr
p Label
bidt Label
bidf Maybe Bool
l, [a
accf, a
acct])
mapCollectSuccessors f :: Label -> (Label, a)
f (CmmSwitch e :: CmmExpr
e ids :: SwitchTargets
ids)
  = let lbls :: [Label]
lbls = SwitchTargets -> [Label]
switchTargetsToList SwitchTargets
ids :: [Label]
        lblMap :: LabelMap (Label, a)
lblMap = [(KeyOf LabelMap, (Label, a))] -> LabelMap (Label, a)
forall (map :: * -> *) a. IsMap map => [(KeyOf map, a)] -> map a
mapFromList ([(KeyOf LabelMap, (Label, a))] -> LabelMap (Label, a))
-> [(KeyOf LabelMap, (Label, a))] -> LabelMap (Label, a)
forall a b. (a -> b) -> a -> b
$ [Label] -> [(Label, a)] -> [(Label, (Label, a))]
forall a b. [a] -> [b] -> [(a, b)]
zip [Label]
lbls ((Label -> (Label, a)) -> [Label] -> [(Label, a)]
forall a b. (a -> b) -> [a] -> [b]
map Label -> (Label, a)
f [Label]
lbls) :: LabelMap (Label, a)
    in ( CmmExpr -> SwitchTargets -> CmmNode O C
CmmSwitch CmmExpr
e
          ((Label -> Label) -> SwitchTargets -> SwitchTargets
mapSwitchTargets
            (\l :: Label
l -> (Label, a) -> Label
forall a b. (a, b) -> a
fst ((Label, a) -> Label) -> (Label, a) -> Label
forall a b. (a -> b) -> a -> b
$ (Label, a) -> KeyOf LabelMap -> LabelMap (Label, a) -> (Label, a)
forall (map :: * -> *) a. IsMap map => a -> KeyOf map -> map a -> a
mapFindWithDefault ([Char] -> (Label, a)
forall a. HasCallStack => [Char] -> a
error "impossible") KeyOf LabelMap
Label
l LabelMap (Label, a)
lblMap) SwitchTargets
ids)
          , ((Label, a) -> a) -> [(Label, a)] -> [a]
forall a b. (a -> b) -> [a] -> [b]
map (Label, a) -> a
forall a b. (a, b) -> b
snd (LabelMap (Label, a) -> [(Label, a)]
forall (map :: * -> *) a. IsMap map => map a -> [a]
mapElems LabelMap (Label, a)
lblMap)
        )
mapCollectSuccessors _ n :: CmmNode O C
n = (CmmNode O C
n, [])

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

-- | Tickish in Cmm context (annotations only)
type CmmTickish = Tickish ()

-- | Tick scope identifier, allowing us to reason about what
-- annotations in a Cmm block should scope over. We especially take
-- care to allow optimisations to reorganise blocks without losing
-- tick association in the process.
data CmmTickScope
  = GlobalScope
    -- ^ The global scope is the "root" of the scope graph. Every
    -- scope is a sub-scope of the global scope. It doesn't make sense
    -- to add ticks to this scope. On the other hand, this means that
    -- setting this scope on a block means no ticks apply to it.

  | SubScope !U.Unique CmmTickScope
    -- ^ Constructs a new sub-scope to an existing scope. This allows
    -- us to translate Core-style scoping rules (see @tickishScoped@)
    -- into the Cmm world. Suppose the following code:
    --
    --   tick<1> case ... of
    --             A -> tick<2> ...
    --             B -> tick<3> ...
    --
    -- We want the top-level tick annotation to apply to blocks
    -- generated for the A and B alternatives. We can achieve that by
    -- generating tick<1> into a block with scope a, while the code
    -- for alternatives A and B gets generated into sub-scopes a/b and
    -- a/c respectively.

  | CombinedScope CmmTickScope CmmTickScope
    -- ^ A combined scope scopes over everything that the two given
    -- scopes cover. It is therefore a sub-scope of either scope. This
    -- is required for optimisations. Consider common block elimination:
    --
    --   A -> tick<2> case ... of
    --     C -> [common]
    --   B -> tick<3> case ... of
    --     D -> [common]
    --
    -- We will generate code for the C and D alternatives, and figure
    -- out afterwards that it's actually common code. Scoping rules
    -- dictate that the resulting common block needs to be covered by
    -- both tick<2> and tick<3>, therefore we need to construct a
    -- scope that is a child to *both* scope. Now we can do that - if
    -- we assign the scopes a/c and b/d to the common-ed up blocks,
    -- the new block could have a combined tick scope a/c+b/d, which
    -- both tick<2> and tick<3> apply to.

-- Note [CmmTick scoping details]:
--
-- The scope of a @CmmTick@ is given by the @CmmEntry@ node of the
-- same block. Note that as a result of this, optimisations making
-- tick scopes more specific can *reduce* the amount of code a tick
-- scopes over. Fixing this would require a separate @CmmTickScope@
-- field for @CmmTick@. Right now we do not do this simply because I
-- couldn't find an example where it actually mattered -- multiple
-- blocks within the same scope generally jump to each other, which
-- prevents common block elimination from happening in the first
-- place. But this is no strong reason, so if Cmm optimisations become
-- more involved in future this might have to be revisited.

-- | Output all scope paths.
scopeToPaths :: CmmTickScope -> [[U.Unique]]
scopeToPaths :: CmmTickScope -> [[Unique]]
scopeToPaths GlobalScope           = [[]]
scopeToPaths (SubScope u :: Unique
u s :: CmmTickScope
s)        = ([Unique] -> [Unique]) -> [[Unique]] -> [[Unique]]
forall a b. (a -> b) -> [a] -> [b]
map (Unique
uUnique -> [Unique] -> [Unique]
forall a. a -> [a] -> [a]
:) (CmmTickScope -> [[Unique]]
scopeToPaths CmmTickScope
s)
scopeToPaths (CombinedScope s1 :: CmmTickScope
s1 s2 :: CmmTickScope
s2) = CmmTickScope -> [[Unique]]
scopeToPaths CmmTickScope
s1 [[Unique]] -> [[Unique]] -> [[Unique]]
forall a. [a] -> [a] -> [a]
++ CmmTickScope -> [[Unique]]
scopeToPaths CmmTickScope
s2

-- | Returns the head uniques of the scopes. This is based on the
-- assumption that the @Unique@ of @SubScope@ identifies the
-- underlying super-scope. Used for efficient equality and comparison,
-- see below.
scopeUniques :: CmmTickScope -> [U.Unique]
scopeUniques :: CmmTickScope -> [Unique]
scopeUniques GlobalScope           = []
scopeUniques (SubScope u :: Unique
u _)        = [Unique
u]
scopeUniques (CombinedScope s1 :: CmmTickScope
s1 s2 :: CmmTickScope
s2) = CmmTickScope -> [Unique]
scopeUniques CmmTickScope
s1 [Unique] -> [Unique] -> [Unique]
forall a. [a] -> [a] -> [a]
++ CmmTickScope -> [Unique]
scopeUniques CmmTickScope
s2

-- Equality and order is based on the head uniques defined above. We
-- take care to short-cut the (extremly) common cases.
instance Eq CmmTickScope where
  GlobalScope    == :: CmmTickScope -> CmmTickScope -> Bool
== GlobalScope     = Bool
True
  GlobalScope    == _               = Bool
False
  _              == GlobalScope     = Bool
False
  (SubScope u :: Unique
u _) == (SubScope u' :: Unique
u' _) = Unique
u Unique -> Unique -> Bool
forall a. Eq a => a -> a -> Bool
== Unique
u'
  (SubScope _ _) == _               = Bool
False
  _              == (SubScope _ _)  = Bool
False
  scope :: CmmTickScope
scope          == scope' :: CmmTickScope
scope'          =
    (Unique -> Unique -> Ordering) -> [Unique] -> [Unique]
forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy Unique -> Unique -> Ordering
nonDetCmpUnique (CmmTickScope -> [Unique]
scopeUniques CmmTickScope
scope) [Unique] -> [Unique] -> Bool
forall a. Eq a => a -> a -> Bool
==
    (Unique -> Unique -> Ordering) -> [Unique] -> [Unique]
forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy Unique -> Unique -> Ordering
nonDetCmpUnique (CmmTickScope -> [Unique]
scopeUniques CmmTickScope
scope')
    -- This is still deterministic because
    -- the order is the same for equal lists

-- This is non-deterministic but we do not currently support deterministic
-- code-generation. See Note [Unique Determinism and code generation]
-- See Note [No Ord for Unique]
instance Ord CmmTickScope where
  compare :: CmmTickScope -> CmmTickScope -> Ordering
compare GlobalScope    GlobalScope     = Ordering
EQ
  compare GlobalScope    _               = Ordering
LT
  compare _              GlobalScope     = Ordering
GT
  compare (SubScope u :: Unique
u _) (SubScope u' :: Unique
u' _) = Unique -> Unique -> Ordering
nonDetCmpUnique Unique
u Unique
u'
  compare scope :: CmmTickScope
scope scope' :: CmmTickScope
scope'                   = (Unique -> Unique -> Ordering) -> [Unique] -> [Unique] -> Ordering
forall a. (a -> a -> Ordering) -> [a] -> [a] -> Ordering
cmpList Unique -> Unique -> Ordering
nonDetCmpUnique
     ((Unique -> Unique -> Ordering) -> [Unique] -> [Unique]
forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy Unique -> Unique -> Ordering
nonDetCmpUnique ([Unique] -> [Unique]) -> [Unique] -> [Unique]
forall a b. (a -> b) -> a -> b
$ CmmTickScope -> [Unique]
scopeUniques CmmTickScope
scope)
     ((Unique -> Unique -> Ordering) -> [Unique] -> [Unique]
forall a. (a -> a -> Ordering) -> [a] -> [a]
sortBy Unique -> Unique -> Ordering
nonDetCmpUnique ([Unique] -> [Unique]) -> [Unique] -> [Unique]
forall a b. (a -> b) -> a -> b
$ CmmTickScope -> [Unique]
scopeUniques CmmTickScope
scope')

instance Outputable CmmTickScope where
  ppr :: CmmTickScope -> SDoc
ppr GlobalScope     = [Char] -> SDoc
text "global"
  ppr (SubScope us :: Unique
us GlobalScope)
                      = Unique -> SDoc
forall a. Outputable a => a -> SDoc
ppr Unique
us
  ppr (SubScope us :: Unique
us s :: CmmTickScope
s) = CmmTickScope -> SDoc
forall a. Outputable a => a -> SDoc
ppr CmmTickScope
s SDoc -> SDoc -> SDoc
<> Char -> SDoc
char '/' SDoc -> SDoc -> SDoc
<> Unique -> SDoc
forall a. Outputable a => a -> SDoc
ppr Unique
us
  ppr combined :: CmmTickScope
combined        = SDoc -> SDoc
parens (SDoc -> SDoc) -> SDoc -> SDoc
forall a b. (a -> b) -> a -> b
$ [SDoc] -> SDoc
hcat ([SDoc] -> SDoc) -> [SDoc] -> SDoc
forall a b. (a -> b) -> a -> b
$ SDoc -> [SDoc] -> [SDoc]
punctuate (Char -> SDoc
char '+') ([SDoc] -> [SDoc]) -> [SDoc] -> [SDoc]
forall a b. (a -> b) -> a -> b
$
                        ([Unique] -> SDoc) -> [[Unique]] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map ([SDoc] -> SDoc
hcat ([SDoc] -> SDoc) -> ([Unique] -> [SDoc]) -> [Unique] -> SDoc
forall b c a. (b -> c) -> (a -> b) -> a -> c
. SDoc -> [SDoc] -> [SDoc]
punctuate (Char -> SDoc
char '/') ([SDoc] -> [SDoc]) -> ([Unique] -> [SDoc]) -> [Unique] -> [SDoc]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (Unique -> SDoc) -> [Unique] -> [SDoc]
forall a b. (a -> b) -> [a] -> [b]
map Unique -> SDoc
forall a. Outputable a => a -> SDoc
ppr ([Unique] -> [SDoc])
-> ([Unique] -> [Unique]) -> [Unique] -> [SDoc]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [Unique] -> [Unique]
forall a. [a] -> [a]
reverse) ([[Unique]] -> [SDoc]) -> [[Unique]] -> [SDoc]
forall a b. (a -> b) -> a -> b
$
                        CmmTickScope -> [[Unique]]
scopeToPaths CmmTickScope
combined

-- | Checks whether two tick scopes are sub-scopes of each other. True
-- if the two scopes are equal.
isTickSubScope :: CmmTickScope -> CmmTickScope -> Bool
isTickSubScope :: CmmTickScope -> CmmTickScope -> Bool
isTickSubScope = CmmTickScope -> CmmTickScope -> Bool
cmp
  where cmp :: CmmTickScope -> CmmTickScope -> Bool
cmp _              GlobalScope             = Bool
True
        cmp GlobalScope    _                       = Bool
False
        cmp (CombinedScope s1 :: CmmTickScope
s1 s2 :: CmmTickScope
s2) s' :: CmmTickScope
s'               = CmmTickScope -> CmmTickScope -> Bool
cmp CmmTickScope
s1 CmmTickScope
s' Bool -> Bool -> Bool
&& CmmTickScope -> CmmTickScope -> Bool
cmp CmmTickScope
s2 CmmTickScope
s'
        cmp s :: CmmTickScope
s              (CombinedScope s1' :: CmmTickScope
s1' s2' :: CmmTickScope
s2') = CmmTickScope -> CmmTickScope -> Bool
cmp CmmTickScope
s CmmTickScope
s1' Bool -> Bool -> Bool
|| CmmTickScope -> CmmTickScope -> Bool
cmp CmmTickScope
s CmmTickScope
s2'
        cmp (SubScope u :: Unique
u s :: CmmTickScope
s) s' :: CmmTickScope
s'@(SubScope u' :: Unique
u' _)      = Unique
u Unique -> Unique -> Bool
forall a. Eq a => a -> a -> Bool
== Unique
u' Bool -> Bool -> Bool
|| CmmTickScope -> CmmTickScope -> Bool
cmp CmmTickScope
s CmmTickScope
s'

-- | Combine two tick scopes. The new scope should be sub-scope of
-- both parameters. We simplfy automatically if one tick scope is a
-- sub-scope of the other already.
combineTickScopes :: CmmTickScope -> CmmTickScope -> CmmTickScope
combineTickScopes :: CmmTickScope -> CmmTickScope -> CmmTickScope
combineTickScopes s1 :: CmmTickScope
s1 s2 :: CmmTickScope
s2
  | CmmTickScope
s1 CmmTickScope -> CmmTickScope -> Bool
`isTickSubScope` CmmTickScope
s2 = CmmTickScope
s1
  | CmmTickScope
s2 CmmTickScope -> CmmTickScope -> Bool
`isTickSubScope` CmmTickScope
s1 = CmmTickScope
s2
  | Bool
otherwise              = CmmTickScope -> CmmTickScope -> CmmTickScope
CombinedScope CmmTickScope
s1 CmmTickScope
s2