{-
(c) The GRASP/AQUA Project, Glasgow University, 1992-2012

Note [Unarisation]
~~~~~~~~~~~~~~~~~~
The idea of this pass is to translate away *all* unboxed-tuple and unboxed-sum
binders. So for example:

  f (x :: (# Int, Bool #)) = f x + f (# 1, True #)

  ==>

  f (x1 :: Int) (x2 :: Bool) = f x1 x2 + f 1 True

It is important that we do this at the STG level and NOT at the Core level
because it would be very hard to make this pass Core-type-preserving. In this
example the type of 'f' changes, for example.

STG fed to the code generators *must* be unarised because the code generators do
not support unboxed tuple and unboxed sum binders natively.

In more detail: (see next note for unboxed sums)

Suppose that a variable x : (# t1, t2 #).

  * At the binding site for x, make up fresh vars  x1:t1, x2:t2

  * Extend the UnariseEnv   x :-> MultiVal [x1,x2]

  * Replace the binding with a curried binding for x1,x2

       Lambda:   \x.e                ==>   \x1 x2. e
       Case alt: MkT a b x c d -> e  ==>   MkT a b x1 x2 c d -> e

  * Replace argument occurrences with a sequence of args via a lookup in
    UnariseEnv

       f a b x c d   ==>   f a b x1 x2 c d

  * Replace tail-call occurrences with an unboxed tuple via a lookup in
    UnariseEnv

       x  ==>  (# x1, x2 #)

    So, for example

       f x = x    ==>   f x1 x2 = (# x1, x2 #)

  * We /always/ eliminate a case expression when

       - It scrutinises an unboxed tuple or unboxed sum

       - The scrutinee is a variable (or when it is an explicit tuple, but the
         simplifier eliminates those)

    The case alternative (there can be only one) can be one of these two
    things:

      - An unboxed tuple pattern. e.g.

          case v of x { (# x1, x2, x3 #) -> ... }

        Scrutinee has to be in form `(# t1, t2, t3 #)` so we just extend the
        environment with

          x :-> MultiVal [t1,t2,t3]
          x1 :-> UnaryVal t1, x2 :-> UnaryVal t2, x3 :-> UnaryVal t3

      - A DEFAULT alternative. Just the same, without the bindings for x1,x2,x3

By the end of this pass, we only have unboxed tuples in return positions.
Unboxed sums are completely eliminated, see next note.

Note [Translating unboxed sums to unboxed tuples]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Unarise also eliminates unboxed sum binders, and translates unboxed sums in
return positions to unboxed tuples. We want to overlap fields of a sum when
translating it to a tuple to have efficient memory layout. When translating a
sum pattern to a tuple pattern, we need to translate it so that binders of sum
alternatives will be mapped to right arguments after the term translation. So
translation of sum DataCon applications to tuple DataCon applications and
translation of sum patterns to tuple patterns need to be in sync.

These translations work like this. Suppose we have

  (# x1 | | ... #) :: (# t1 | t2 | ... #)

remember that t1, t2 ... can be sums and tuples too. So we first generate
layouts of those. Then we "merge" layouts of each alternative, which gives us a
sum layout with best overlapping possible.

Layout of a flat type 'ty1' is just [ty1].
Layout of a tuple is just concatenation of layouts of its fields.

For layout of a sum type,

  - We first get layouts of all alternatives.
  - We sort these layouts based on their "slot types".
  - We merge all the alternatives.

For example, say we have (# (# Int#, Char #) | (# Int#, Int# #) | Int# #)

  - Layouts of alternatives: [ [Word, Ptr], [Word, Word], [Word] ]
  - Sorted: [ [Ptr, Word], [Word, Word], [Word] ]
  - Merge all alternatives together: [ Ptr, Word, Word ]

We add a slot for the tag to the first position. So our tuple type is

  (# Tag#, Any, Word#, Word# #)
  (we use Any for pointer slots)

Now, any term of this sum type needs to generate a tuple of this type instead.
The translation works by simply putting arguments to first slots that they fit
in. Suppose we had

  (# (# 42#, 'c' #) | | #)

42# fits in Word#, 'c' fits in Any, so we generate this application:

  (# 1#, 'c', 42#, rubbish #)

Another example using the same type: (# | (# 2#, 3# #) | #). 2# fits in Word#,
3# fits in Word #, so we get:

  (# 2#, rubbish, 2#, 3# #).

Note [Types in StgConApp]
~~~~~~~~~~~~~~~~~~~~~~~~~
Suppose we have this unboxed sum term:

  (# 123 | #)

What will be the unboxed tuple representation? We can't tell without knowing the
type of this term. For example, these are all valid tuples for this:

  (# 1#, 123 #)          -- when type is (# Int | String #)
  (# 1#, 123, rubbish #) -- when type is (# Int | Float# #)
  (# 1#, 123, rubbish, rubbish #)
                         -- when type is (# Int | (# Int, Int, Int #) #)

So we pass type arguments of the DataCon's TyCon in StgConApp to decide what
layout to use. Note that unlifted values can't be let-bound, so we don't need
types in StgRhsCon.

Note [UnariseEnv can map to literals]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To avoid redundant case expressions when unarising unboxed sums, UnariseEnv
needs to map variables to literals too. Suppose we have this Core:

  f (# x | #)

  ==> (CorePrep)

  case (# x | #) of y {
    _ -> f y
  }

  ==> (MultiVal)

  case (# 1#, x #) of [x1, x2] {
    _ -> f x1 x2
  }

To eliminate this case expression we need to map x1 to 1# in UnariseEnv:

  x1 :-> UnaryVal 1#, x2 :-> UnaryVal x

so that `f x1 x2` becomes `f 1# x`.

Note [Unarisation and arity]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Because of unarisation, the arity that will be recorded in the generated info
table for an Id may be larger than the idArity. Instead we record what we call
the RepArity, which is the Arity taking into account any expanded arguments, and
corresponds to the number of (possibly-void) *registers* arguments will arrive
in.

Note [Post-unarisation invariants]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
STG programs after unarisation have these invariants:

  * No unboxed sums at all.

  * No unboxed tuple binders. Tuples only appear in return position.

  * DataCon applications (StgRhsCon and StgConApp) don't have void arguments.
    This means that it's safe to wrap `StgArg`s of DataCon applications with
    `GHC.StgToCmm.Env.NonVoid`, for example.

  * Alt binders (binders in patterns) are always non-void.

  * Binders always have zero (for void arguments) or one PrimRep.
-}

{-# LANGUAGE CPP, TupleSections #-}

module UnariseStg (unarise) where

#include "HsVersions.h"

import GhcPrelude

import BasicTypes
import CoreSyn
import DataCon
import FastString (FastString, mkFastString)
import Id
import Literal
import MkCore (aBSENT_SUM_FIELD_ERROR_ID)
import MkId (voidPrimId, voidArgId)
import MonadUtils (mapAccumLM)
import Outputable
import RepType
import StgSyn
import Type
import TysPrim (intPrimTy,wordPrimTy,word64PrimTy)
import TysWiredIn
import UniqSupply
import Util
import VarEnv

import Data.Bifunctor (second)
import Data.Maybe (mapMaybe)
import qualified Data.IntMap as IM

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

-- | A mapping from binders to the Ids they were expanded/renamed to.
--
--   x :-> MultiVal [a,b,c] in rho
--
-- iff  x's typePrimRep is not a singleton, or equivalently
--      x's type is an unboxed tuple, sum or void.
--
--    x :-> UnaryVal x'
--
-- iff x's RepType is UnaryRep or equivalently
--     x's type is not unboxed tuple, sum or void.
--
-- So
--     x :-> MultiVal [a] in rho
-- means x is represented by singleton tuple.
--
--     x :-> MultiVal [] in rho
-- means x is void.
--
-- INVARIANT: OutStgArgs in the range only have NvUnaryTypes
--            (i.e. no unboxed tuples, sums or voids)
--
type UnariseEnv = VarEnv UnariseVal

data UnariseVal
  = MultiVal [OutStgArg] -- MultiVal to tuple. Can be empty list (void).
  | UnaryVal OutStgArg   -- See NOTE [Renaming during unarisation].

instance Outputable UnariseVal where
  ppr :: UnariseVal -> SDoc
ppr (MultiVal [OutStgArg]
args) = String -> SDoc
text String
"MultiVal" SDoc -> SDoc -> SDoc
<+> [OutStgArg] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [OutStgArg]
args
  ppr (UnaryVal OutStgArg
arg)   = String -> SDoc
text String
"UnaryVal" SDoc -> SDoc -> SDoc
<+> OutStgArg -> SDoc
forall a. Outputable a => a -> SDoc
ppr OutStgArg
arg

-- | Extend the environment, checking the UnariseEnv invariant.
extendRho :: UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho :: UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x (MultiVal [OutStgArg]
args)
  = ASSERT(all (isNvUnaryType . stgArgType) args)
    UnariseEnv -> Id -> UnariseVal -> UnariseEnv
forall a. VarEnv a -> Id -> a -> VarEnv a
extendVarEnv UnariseEnv
rho Id
x ([OutStgArg] -> UnariseVal
MultiVal [OutStgArg]
args)
extendRho UnariseEnv
rho Id
x (UnaryVal OutStgArg
val)
  = ASSERT(isNvUnaryType (stgArgType val))
    UnariseEnv -> Id -> UnariseVal -> UnariseEnv
forall a. VarEnv a -> Id -> a -> VarEnv a
extendVarEnv UnariseEnv
rho Id
x (OutStgArg -> UnariseVal
UnaryVal OutStgArg
val)

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

unarise :: UniqSupply -> [StgTopBinding] -> [StgTopBinding]
unarise :: UniqSupply -> [StgTopBinding] -> [StgTopBinding]
unarise UniqSupply
us [StgTopBinding]
binds = UniqSupply -> UniqSM [StgTopBinding] -> [StgTopBinding]
forall a. UniqSupply -> UniqSM a -> a
initUs_ UniqSupply
us ((StgTopBinding -> UniqSM StgTopBinding)
-> [StgTopBinding] -> UniqSM [StgTopBinding]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (UnariseEnv -> StgTopBinding -> UniqSM StgTopBinding
unariseTopBinding UnariseEnv
forall a. VarEnv a
emptyVarEnv) [StgTopBinding]
binds)

unariseTopBinding :: UnariseEnv -> StgTopBinding -> UniqSM StgTopBinding
unariseTopBinding :: UnariseEnv -> StgTopBinding -> UniqSM StgTopBinding
unariseTopBinding UnariseEnv
rho (StgTopLifted GenStgBinding 'Vanilla
bind)
  = GenStgBinding 'Vanilla -> StgTopBinding
forall (pass :: StgPass).
GenStgBinding pass -> GenStgTopBinding pass
StgTopLifted (GenStgBinding 'Vanilla -> StgTopBinding)
-> UniqSM (GenStgBinding 'Vanilla) -> UniqSM StgTopBinding
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv
-> GenStgBinding 'Vanilla -> UniqSM (GenStgBinding 'Vanilla)
unariseBinding UnariseEnv
rho GenStgBinding 'Vanilla
bind
unariseTopBinding UnariseEnv
_ bind :: StgTopBinding
bind@StgTopStringLit{} = StgTopBinding -> UniqSM StgTopBinding
forall (m :: * -> *) a. Monad m => a -> m a
return StgTopBinding
bind

unariseBinding :: UnariseEnv -> StgBinding -> UniqSM StgBinding
unariseBinding :: UnariseEnv
-> GenStgBinding 'Vanilla -> UniqSM (GenStgBinding 'Vanilla)
unariseBinding UnariseEnv
rho (StgNonRec BinderP 'Vanilla
x GenStgRhs 'Vanilla
rhs)
  = BinderP 'Vanilla -> GenStgRhs 'Vanilla -> GenStgBinding 'Vanilla
forall (pass :: StgPass).
BinderP pass -> GenStgRhs pass -> GenStgBinding pass
StgNonRec BinderP 'Vanilla
x (GenStgRhs 'Vanilla -> GenStgBinding 'Vanilla)
-> UniqSM (GenStgRhs 'Vanilla) -> UniqSM (GenStgBinding 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv -> GenStgRhs 'Vanilla -> UniqSM (GenStgRhs 'Vanilla)
unariseRhs UnariseEnv
rho GenStgRhs 'Vanilla
rhs
unariseBinding UnariseEnv
rho (StgRec [(BinderP 'Vanilla, GenStgRhs 'Vanilla)]
xrhss)
  = [(Id, GenStgRhs 'Vanilla)] -> GenStgBinding 'Vanilla
forall (pass :: StgPass).
[(BinderP pass, GenStgRhs pass)] -> GenStgBinding pass
StgRec ([(Id, GenStgRhs 'Vanilla)] -> GenStgBinding 'Vanilla)
-> UniqSM [(Id, GenStgRhs 'Vanilla)]
-> UniqSM (GenStgBinding 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> ((Id, GenStgRhs 'Vanilla) -> UniqSM (Id, GenStgRhs 'Vanilla))
-> [(Id, GenStgRhs 'Vanilla)] -> UniqSM [(Id, GenStgRhs 'Vanilla)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (\(Id
x, GenStgRhs 'Vanilla
rhs) -> (Id
x,) (GenStgRhs 'Vanilla -> (Id, GenStgRhs 'Vanilla))
-> UniqSM (GenStgRhs 'Vanilla) -> UniqSM (Id, GenStgRhs 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv -> GenStgRhs 'Vanilla -> UniqSM (GenStgRhs 'Vanilla)
unariseRhs UnariseEnv
rho GenStgRhs 'Vanilla
rhs) [(Id, GenStgRhs 'Vanilla)]
[(BinderP 'Vanilla, GenStgRhs 'Vanilla)]
xrhss

unariseRhs :: UnariseEnv -> StgRhs -> UniqSM StgRhs
unariseRhs :: UnariseEnv -> GenStgRhs 'Vanilla -> UniqSM (GenStgRhs 'Vanilla)
unariseRhs UnariseEnv
rho (StgRhsClosure XRhsClosure 'Vanilla
ext CostCentreStack
ccs UpdateFlag
update_flag [BinderP 'Vanilla]
args GenStgExpr 'Vanilla
expr)
  = do (UnariseEnv
rho', [Id]
args1) <- UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseFunArgBinders UnariseEnv
rho [Id]
[BinderP 'Vanilla]
args
       GenStgExpr 'Vanilla
expr' <- UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho' GenStgExpr 'Vanilla
expr
       GenStgRhs 'Vanilla -> UniqSM (GenStgRhs 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (XRhsClosure 'Vanilla
-> CostCentreStack
-> UpdateFlag
-> [BinderP 'Vanilla]
-> GenStgExpr 'Vanilla
-> GenStgRhs 'Vanilla
forall (pass :: StgPass).
XRhsClosure pass
-> CostCentreStack
-> UpdateFlag
-> [BinderP pass]
-> GenStgExpr pass
-> GenStgRhs pass
StgRhsClosure XRhsClosure 'Vanilla
ext CostCentreStack
ccs UpdateFlag
update_flag [Id]
[BinderP 'Vanilla]
args1 GenStgExpr 'Vanilla
expr')

unariseRhs UnariseEnv
rho (StgRhsCon CostCentreStack
ccs DataCon
con [OutStgArg]
args)
  = ASSERT(not (isUnboxedTupleCon con || isUnboxedSumCon con))
    GenStgRhs 'Vanilla -> UniqSM (GenStgRhs 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (CostCentreStack -> DataCon -> [OutStgArg] -> GenStgRhs 'Vanilla
forall (pass :: StgPass).
CostCentreStack -> DataCon -> [OutStgArg] -> GenStgRhs pass
StgRhsCon CostCentreStack
ccs DataCon
con (UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseConArgs UnariseEnv
rho [OutStgArg]
args))

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

unariseExpr :: UnariseEnv -> StgExpr -> UniqSM StgExpr

unariseExpr :: UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho e :: GenStgExpr 'Vanilla
e@(StgApp Id
f [])
  = case UnariseEnv -> Id -> Maybe UnariseVal
forall a. VarEnv a -> Id -> Maybe a
lookupVarEnv UnariseEnv
rho Id
f of
      Just (MultiVal [OutStgArg]
args)  -- Including empty tuples
        -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return ([OutStgArg] -> GenStgExpr 'Vanilla
mkTuple [OutStgArg]
args)
      Just (UnaryVal (StgVarArg Id
f'))
        -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (Id -> [OutStgArg] -> GenStgExpr 'Vanilla
forall (pass :: StgPass). Id -> [OutStgArg] -> GenStgExpr pass
StgApp Id
f' [])
      Just (UnaryVal (StgLitArg Literal
f'))
        -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (Literal -> GenStgExpr 'Vanilla
forall (pass :: StgPass). Literal -> GenStgExpr pass
StgLit Literal
f')
      Maybe UnariseVal
Nothing
        -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return GenStgExpr 'Vanilla
e

unariseExpr UnariseEnv
rho e :: GenStgExpr 'Vanilla
e@(StgApp Id
f [OutStgArg]
args)
  = GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (Id -> [OutStgArg] -> GenStgExpr 'Vanilla
forall (pass :: StgPass). Id -> [OutStgArg] -> GenStgExpr pass
StgApp Id
f' (UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseFunArgs UnariseEnv
rho [OutStgArg]
args))
  where
    f' :: Id
f' = case UnariseEnv -> Id -> Maybe UnariseVal
forall a. VarEnv a -> Id -> Maybe a
lookupVarEnv UnariseEnv
rho Id
f of
           Just (UnaryVal (StgVarArg Id
f')) -> Id
f'
           Maybe UnariseVal
Nothing -> Id
f
           Maybe UnariseVal
err -> String -> SDoc -> Id
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"unariseExpr - app2" (GenStgExpr 'Vanilla -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenStgExpr 'Vanilla
e SDoc -> SDoc -> SDoc
$$ Maybe UnariseVal -> SDoc
forall a. Outputable a => a -> SDoc
ppr Maybe UnariseVal
err)
               -- Can't happen because 'args' is non-empty, and
               -- a tuple or sum cannot be applied to anything

unariseExpr UnariseEnv
_ (StgLit Literal
l)
  = GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (Literal -> GenStgExpr 'Vanilla
forall (pass :: StgPass). Literal -> GenStgExpr pass
StgLit Literal
l)

unariseExpr UnariseEnv
rho (StgConApp DataCon
dc [OutStgArg]
args [Type]
ty_args)
  | Just [OutStgArg]
args' <- UnariseEnv -> DataCon -> [OutStgArg] -> [Type] -> Maybe [OutStgArg]
unariseMulti_maybe UnariseEnv
rho DataCon
dc [OutStgArg]
args [Type]
ty_args
  = GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return ([OutStgArg] -> GenStgExpr 'Vanilla
mkTuple [OutStgArg]
args')

  | Bool
otherwise
  , let args' :: [OutStgArg]
args' = UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseConArgs UnariseEnv
rho [OutStgArg]
args
  = GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (DataCon -> [OutStgArg] -> [Type] -> GenStgExpr 'Vanilla
forall (pass :: StgPass).
DataCon -> [OutStgArg] -> [Type] -> GenStgExpr pass
StgConApp DataCon
dc [OutStgArg]
args' ((OutStgArg -> Type) -> [OutStgArg] -> [Type]
forall a b. (a -> b) -> [a] -> [b]
map OutStgArg -> Type
stgArgType [OutStgArg]
args'))

unariseExpr UnariseEnv
rho (StgOpApp StgOp
op [OutStgArg]
args Type
ty)
  = GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (StgOp -> [OutStgArg] -> Type -> GenStgExpr 'Vanilla
forall (pass :: StgPass).
StgOp -> [OutStgArg] -> Type -> GenStgExpr pass
StgOpApp StgOp
op (UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseFunArgs UnariseEnv
rho [OutStgArg]
args) Type
ty)

unariseExpr UnariseEnv
_ e :: GenStgExpr 'Vanilla
e@StgLam{}
  = String -> SDoc -> UniqSM (GenStgExpr 'Vanilla)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"unariseExpr: found lambda" (GenStgExpr 'Vanilla -> SDoc
forall a. Outputable a => a -> SDoc
ppr GenStgExpr 'Vanilla
e)

unariseExpr UnariseEnv
rho (StgCase GenStgExpr 'Vanilla
scrut BinderP 'Vanilla
bndr AltType
alt_ty [GenStgAlt 'Vanilla]
alts)
  -- tuple/sum binders in the scrutinee can always be eliminated
  | StgApp Id
v [] <- GenStgExpr 'Vanilla
scrut
  , Just (MultiVal [OutStgArg]
xs) <- UnariseEnv -> Id -> Maybe UnariseVal
forall a. VarEnv a -> Id -> Maybe a
lookupVarEnv UnariseEnv
rho Id
v
  = UnariseEnv
-> [OutStgArg]
-> Id
-> AltType
-> [GenStgAlt 'Vanilla]
-> UniqSM (GenStgExpr 'Vanilla)
elimCase UnariseEnv
rho [OutStgArg]
xs Id
BinderP 'Vanilla
bndr AltType
alt_ty [GenStgAlt 'Vanilla]
alts

  -- Handle strict lets for tuples and sums:
  --   case (# a,b #) of r -> rhs
  -- and analogously for sums
  | StgConApp DataCon
dc [OutStgArg]
args [Type]
ty_args <- GenStgExpr 'Vanilla
scrut
  , Just [OutStgArg]
args' <- UnariseEnv -> DataCon -> [OutStgArg] -> [Type] -> Maybe [OutStgArg]
unariseMulti_maybe UnariseEnv
rho DataCon
dc [OutStgArg]
args [Type]
ty_args
  = UnariseEnv
-> [OutStgArg]
-> Id
-> AltType
-> [GenStgAlt 'Vanilla]
-> UniqSM (GenStgExpr 'Vanilla)
elimCase UnariseEnv
rho [OutStgArg]
args' Id
BinderP 'Vanilla
bndr AltType
alt_ty [GenStgAlt 'Vanilla]
alts

  -- general case
  | Bool
otherwise
  = do GenStgExpr 'Vanilla
scrut' <- UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho GenStgExpr 'Vanilla
scrut
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
alts'  <- UnariseEnv
-> AltType
-> Id
-> [GenStgAlt 'Vanilla]
-> UniqSM [GenStgAlt 'Vanilla]
unariseAlts UnariseEnv
rho AltType
alt_ty Id
BinderP 'Vanilla
bndr [GenStgAlt 'Vanilla]
alts
       GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (GenStgExpr 'Vanilla
-> BinderP 'Vanilla
-> AltType
-> [GenStgAlt 'Vanilla]
-> GenStgExpr 'Vanilla
forall (pass :: StgPass).
GenStgExpr pass
-> BinderP pass -> AltType -> [GenStgAlt pass] -> GenStgExpr pass
StgCase GenStgExpr 'Vanilla
scrut' BinderP 'Vanilla
bndr AltType
alt_ty [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts')
                       -- bndr may have a unboxed sum/tuple type but it will be
                       -- dead after unarise (checked in StgLint)

unariseExpr UnariseEnv
rho (StgLet XLet 'Vanilla
ext GenStgBinding 'Vanilla
bind GenStgExpr 'Vanilla
e)
  = XLet 'Vanilla
-> GenStgBinding 'Vanilla
-> GenStgExpr 'Vanilla
-> GenStgExpr 'Vanilla
forall (pass :: StgPass).
XLet pass
-> GenStgBinding pass -> GenStgExpr pass -> GenStgExpr pass
StgLet XLet 'Vanilla
ext (GenStgBinding 'Vanilla
 -> GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
-> UniqSM (GenStgBinding 'Vanilla)
-> UniqSM (GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv
-> GenStgBinding 'Vanilla -> UniqSM (GenStgBinding 'Vanilla)
unariseBinding UnariseEnv
rho GenStgBinding 'Vanilla
bind UniqSM (GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
-> UniqSM (GenStgExpr 'Vanilla) -> UniqSM (GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho GenStgExpr 'Vanilla
e

unariseExpr UnariseEnv
rho (StgLetNoEscape XLetNoEscape 'Vanilla
ext GenStgBinding 'Vanilla
bind GenStgExpr 'Vanilla
e)
  = XLetNoEscape 'Vanilla
-> GenStgBinding 'Vanilla
-> GenStgExpr 'Vanilla
-> GenStgExpr 'Vanilla
forall (pass :: StgPass).
XLetNoEscape pass
-> GenStgBinding pass -> GenStgExpr pass -> GenStgExpr pass
StgLetNoEscape XLetNoEscape 'Vanilla
ext (GenStgBinding 'Vanilla
 -> GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
-> UniqSM (GenStgBinding 'Vanilla)
-> UniqSM (GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv
-> GenStgBinding 'Vanilla -> UniqSM (GenStgBinding 'Vanilla)
unariseBinding UnariseEnv
rho GenStgBinding 'Vanilla
bind UniqSM (GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
-> UniqSM (GenStgExpr 'Vanilla) -> UniqSM (GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho GenStgExpr 'Vanilla
e

unariseExpr UnariseEnv
rho (StgTick Tickish Id
tick GenStgExpr 'Vanilla
e)
  = Tickish Id -> GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla
forall (pass :: StgPass).
Tickish Id -> GenStgExpr pass -> GenStgExpr pass
StgTick Tickish Id
tick (GenStgExpr 'Vanilla -> GenStgExpr 'Vanilla)
-> UniqSM (GenStgExpr 'Vanilla) -> UniqSM (GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho GenStgExpr 'Vanilla
e

-- Doesn't return void args.
unariseMulti_maybe :: UnariseEnv -> DataCon -> [InStgArg] -> [Type] -> Maybe [OutStgArg]
unariseMulti_maybe :: UnariseEnv -> DataCon -> [OutStgArg] -> [Type] -> Maybe [OutStgArg]
unariseMulti_maybe UnariseEnv
rho DataCon
dc [OutStgArg]
args [Type]
ty_args
  | DataCon -> Bool
isUnboxedTupleCon DataCon
dc
  = [OutStgArg] -> Maybe [OutStgArg]
forall a. a -> Maybe a
Just (UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseConArgs UnariseEnv
rho [OutStgArg]
args)

  | DataCon -> Bool
isUnboxedSumCon DataCon
dc
  , let args1 :: [OutStgArg]
args1 = ASSERT(isSingleton args) (unariseConArgs rho args)
  = [OutStgArg] -> Maybe [OutStgArg]
forall a. a -> Maybe a
Just (DataCon -> [Type] -> [OutStgArg] -> [OutStgArg]
mkUbxSum DataCon
dc [Type]
ty_args [OutStgArg]
args1)

  | Bool
otherwise
  = Maybe [OutStgArg]
forall a. Maybe a
Nothing

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

elimCase :: UnariseEnv
         -> [OutStgArg] -- non-void args
         -> InId -> AltType -> [InStgAlt] -> UniqSM OutStgExpr

elimCase :: UnariseEnv
-> [OutStgArg]
-> Id
-> AltType
-> [GenStgAlt 'Vanilla]
-> UniqSM (GenStgExpr 'Vanilla)
elimCase UnariseEnv
rho [OutStgArg]
args Id
bndr (MultiValAlt Int
_) [(AltCon
_, [BinderP 'Vanilla]
bndrs, GenStgExpr 'Vanilla
rhs)]
  = do let rho1 :: UnariseEnv
rho1 = UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
bndr ([OutStgArg] -> UnariseVal
MultiVal [OutStgArg]
args)
           rho2 :: UnariseEnv
rho2
             | Id -> Bool
isUnboxedTupleBndr Id
bndr
             = [Id] -> [OutStgArg] -> UnariseEnv -> UnariseEnv
mapTupleIdBinders [Id]
[BinderP 'Vanilla]
bndrs [OutStgArg]
args UnariseEnv
rho1
             | Bool
otherwise
             = ASSERT(isUnboxedSumBndr bndr)
               if [Id] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [Id]
[BinderP 'Vanilla]
bndrs then UnariseEnv
rho1
                             else [Id] -> [OutStgArg] -> UnariseEnv -> UnariseEnv
mapSumIdBinders [Id]
[BinderP 'Vanilla]
bndrs [OutStgArg]
args UnariseEnv
rho1

       UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho2 GenStgExpr 'Vanilla
rhs

elimCase UnariseEnv
rho [OutStgArg]
args Id
bndr (MultiValAlt Int
_) [GenStgAlt 'Vanilla]
alts
  | Id -> Bool
isUnboxedSumBndr Id
bndr
  = do let (OutStgArg
tag_arg : [OutStgArg]
real_args) = [OutStgArg]
args
       Id
tag_bndr <- FastString -> Type -> UniqSM Id
mkId (String -> FastString
mkFastString String
"tag") Type
tagTy
          -- this won't be used but we need a binder anyway
       let rho1 :: UnariseEnv
rho1 = UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
bndr ([OutStgArg] -> UnariseVal
MultiVal [OutStgArg]
args)
           scrut' :: GenStgExpr pass
scrut' = case OutStgArg
tag_arg of
                      StgVarArg Id
v     -> Id -> [OutStgArg] -> GenStgExpr pass
forall (pass :: StgPass). Id -> [OutStgArg] -> GenStgExpr pass
StgApp Id
v []
                      StgLitArg Literal
l     -> Literal -> GenStgExpr pass
forall (pass :: StgPass). Literal -> GenStgExpr pass
StgLit Literal
l

       [(AltCon, [Id], GenStgExpr 'Vanilla)]
alts' <- UnariseEnv
-> [OutStgArg]
-> [GenStgAlt 'Vanilla]
-> UniqSM [GenStgAlt 'Vanilla]
unariseSumAlts UnariseEnv
rho1 [OutStgArg]
real_args [GenStgAlt 'Vanilla]
alts
       GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return (GenStgExpr 'Vanilla
-> BinderP 'Vanilla
-> AltType
-> [GenStgAlt 'Vanilla]
-> GenStgExpr 'Vanilla
forall (pass :: StgPass).
GenStgExpr pass
-> BinderP pass -> AltType -> [GenStgAlt pass] -> GenStgExpr pass
StgCase GenStgExpr 'Vanilla
forall (pass :: StgPass). GenStgExpr pass
scrut' Id
BinderP 'Vanilla
tag_bndr AltType
tagAltTy [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts')

elimCase UnariseEnv
_ [OutStgArg]
args Id
bndr AltType
alt_ty [GenStgAlt 'Vanilla]
alts
  = String -> SDoc -> UniqSM (GenStgExpr 'Vanilla)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"elimCase - unhandled case"
      ([OutStgArg] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [OutStgArg]
args SDoc -> SDoc -> SDoc
<+> Id -> SDoc
forall a. Outputable a => a -> SDoc
ppr Id
bndr SDoc -> SDoc -> SDoc
<+> AltType -> SDoc
forall a. Outputable a => a -> SDoc
ppr AltType
alt_ty SDoc -> SDoc -> SDoc
$$ [(AltCon, [Id], GenStgExpr 'Vanilla)] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts)

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

unariseAlts :: UnariseEnv -> AltType -> InId -> [StgAlt] -> UniqSM [StgAlt]
unariseAlts :: UnariseEnv
-> AltType
-> Id
-> [GenStgAlt 'Vanilla]
-> UniqSM [GenStgAlt 'Vanilla]
unariseAlts UnariseEnv
rho (MultiValAlt Int
n) Id
bndr [(AltCon
DEFAULT, [], GenStgExpr 'Vanilla
e)]
  | Id -> Bool
isUnboxedTupleBndr Id
bndr
  = do (UnariseEnv
rho', [Id]
ys) <- UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseConArgBinder UnariseEnv
rho Id
bndr
       GenStgExpr 'Vanilla
e' <- UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho' GenStgExpr 'Vanilla
e
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (m :: * -> *) a. Monad m => a -> m a
return [(DataCon -> AltCon
DataAlt (Boxity -> Int -> DataCon
tupleDataCon Boxity
Unboxed Int
n), [Id]
ys, GenStgExpr 'Vanilla
e')]

unariseAlts UnariseEnv
rho (MultiValAlt Int
n) Id
bndr [(DataAlt DataCon
_, [BinderP 'Vanilla]
ys, GenStgExpr 'Vanilla
e)]
  | Id -> Bool
isUnboxedTupleBndr Id
bndr
  = do (UnariseEnv
rho', [Id]
ys1) <- UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseConArgBinders UnariseEnv
rho [Id]
[BinderP 'Vanilla]
ys
       MASSERT(ys1 `lengthIs` n)
       let rho'' :: UnariseEnv
rho'' = UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho' Id
bndr ([OutStgArg] -> UnariseVal
MultiVal ((Id -> OutStgArg) -> [Id] -> [OutStgArg]
forall a b. (a -> b) -> [a] -> [b]
map Id -> OutStgArg
StgVarArg [Id]
ys1))
       GenStgExpr 'Vanilla
e' <- UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho'' GenStgExpr 'Vanilla
e
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (m :: * -> *) a. Monad m => a -> m a
return [(DataCon -> AltCon
DataAlt (Boxity -> Int -> DataCon
tupleDataCon Boxity
Unboxed Int
n), [Id]
ys1, GenStgExpr 'Vanilla
e')]

unariseAlts UnariseEnv
_ (MultiValAlt Int
_) Id
bndr [GenStgAlt 'Vanilla]
alts
  | Id -> Bool
isUnboxedTupleBndr Id
bndr
  = String -> SDoc -> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"unariseExpr: strange multi val alts" ([(AltCon, [Id], GenStgExpr 'Vanilla)] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts)

-- In this case we don't need to scrutinize the tag bit
unariseAlts UnariseEnv
rho (MultiValAlt Int
_) Id
bndr [(AltCon
DEFAULT, [BinderP 'Vanilla]
_, GenStgExpr 'Vanilla
rhs)]
  | Id -> Bool
isUnboxedSumBndr Id
bndr
  = do (UnariseEnv
rho_sum_bndrs, [Id]
sum_bndrs) <- UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseConArgBinder UnariseEnv
rho Id
bndr
       GenStgExpr 'Vanilla
rhs' <- UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho_sum_bndrs GenStgExpr 'Vanilla
rhs
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (m :: * -> *) a. Monad m => a -> m a
return [(DataCon -> AltCon
DataAlt (Boxity -> Int -> DataCon
tupleDataCon Boxity
Unboxed ([Id] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [Id]
sum_bndrs)), [Id]
sum_bndrs, GenStgExpr 'Vanilla
rhs')]

unariseAlts UnariseEnv
rho (MultiValAlt Int
_) Id
bndr [GenStgAlt 'Vanilla]
alts
  | Id -> Bool
isUnboxedSumBndr Id
bndr
  = do (UnariseEnv
rho_sum_bndrs, scrt_bndrs :: [Id]
scrt_bndrs@(Id
tag_bndr : [Id]
real_bndrs)) <- UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseConArgBinder UnariseEnv
rho Id
bndr
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
alts' <- UnariseEnv
-> [OutStgArg]
-> [GenStgAlt 'Vanilla]
-> UniqSM [GenStgAlt 'Vanilla]
unariseSumAlts UnariseEnv
rho_sum_bndrs ((Id -> OutStgArg) -> [Id] -> [OutStgArg]
forall a b. (a -> b) -> [a] -> [b]
map Id -> OutStgArg
StgVarArg [Id]
real_bndrs) [GenStgAlt 'Vanilla]
alts
       let inner_case :: GenStgExpr 'Vanilla
inner_case = GenStgExpr 'Vanilla
-> BinderP 'Vanilla
-> AltType
-> [GenStgAlt 'Vanilla]
-> GenStgExpr 'Vanilla
forall (pass :: StgPass).
GenStgExpr pass
-> BinderP pass -> AltType -> [GenStgAlt pass] -> GenStgExpr pass
StgCase (Id -> [OutStgArg] -> GenStgExpr 'Vanilla
forall (pass :: StgPass). Id -> [OutStgArg] -> GenStgExpr pass
StgApp Id
tag_bndr []) Id
BinderP 'Vanilla
tag_bndr AltType
tagAltTy [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts'
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (m :: * -> *) a. Monad m => a -> m a
return [ (DataCon -> AltCon
DataAlt (Boxity -> Int -> DataCon
tupleDataCon Boxity
Unboxed ([Id] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [Id]
scrt_bndrs)),
                 [Id]
scrt_bndrs,
                 GenStgExpr 'Vanilla
inner_case) ]

unariseAlts UnariseEnv
rho AltType
_ Id
_ [GenStgAlt 'Vanilla]
alts
  = ((AltCon, [Id], GenStgExpr 'Vanilla)
 -> UniqSM (AltCon, [Id], GenStgExpr 'Vanilla))
-> [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (\(AltCon, [Id], GenStgExpr 'Vanilla)
alt -> UnariseEnv -> GenStgAlt 'Vanilla -> UniqSM (GenStgAlt 'Vanilla)
unariseAlt UnariseEnv
rho (AltCon, [Id], GenStgExpr 'Vanilla)
GenStgAlt 'Vanilla
alt) [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts

unariseAlt :: UnariseEnv -> StgAlt -> UniqSM StgAlt
unariseAlt :: UnariseEnv -> GenStgAlt 'Vanilla -> UniqSM (GenStgAlt 'Vanilla)
unariseAlt UnariseEnv
rho (AltCon
con, [BinderP 'Vanilla]
xs, GenStgExpr 'Vanilla
e)
  = do (UnariseEnv
rho', [Id]
xs') <- UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseConArgBinders UnariseEnv
rho [Id]
[BinderP 'Vanilla]
xs
       (AltCon
con, [Id]
xs',) (GenStgExpr 'Vanilla -> (AltCon, [Id], GenStgExpr 'Vanilla))
-> UniqSM (GenStgExpr 'Vanilla)
-> UniqSM (AltCon, [Id], GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho' GenStgExpr 'Vanilla
e

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

-- | Make alternatives that match on the tag of a sum
-- (i.e. generate LitAlts for the tag)
unariseSumAlts :: UnariseEnv
               -> [StgArg] -- sum components _excluding_ the tag bit.
               -> [StgAlt] -- original alternative with sum LHS
               -> UniqSM [StgAlt]
unariseSumAlts :: UnariseEnv
-> [OutStgArg]
-> [GenStgAlt 'Vanilla]
-> UniqSM [GenStgAlt 'Vanilla]
unariseSumAlts UnariseEnv
env [OutStgArg]
args [GenStgAlt 'Vanilla]
alts
  = do [(AltCon, [Id], GenStgExpr 'Vanilla)]
alts' <- ((AltCon, [Id], GenStgExpr 'Vanilla)
 -> UniqSM (AltCon, [Id], GenStgExpr 'Vanilla))
-> [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (UnariseEnv
-> [OutStgArg] -> GenStgAlt 'Vanilla -> UniqSM (GenStgAlt 'Vanilla)
unariseSumAlt UnariseEnv
env [OutStgArg]
args) [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts
       [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> UniqSM [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall (m :: * -> *) a. Monad m => a -> m a
return ([GenStgAlt 'Vanilla] -> [GenStgAlt 'Vanilla]
mkDefaultLitAlt [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts')

unariseSumAlt :: UnariseEnv
              -> [StgArg] -- sum components _excluding_ the tag bit.
              -> StgAlt   -- original alternative with sum LHS
              -> UniqSM StgAlt
unariseSumAlt :: UnariseEnv
-> [OutStgArg] -> GenStgAlt 'Vanilla -> UniqSM (GenStgAlt 'Vanilla)
unariseSumAlt UnariseEnv
rho [OutStgArg]
_ (AltCon
DEFAULT, [BinderP 'Vanilla]
_, GenStgExpr 'Vanilla
e)
  = ( AltCon
DEFAULT, [], ) (GenStgExpr 'Vanilla -> (AltCon, [Id], GenStgExpr 'Vanilla))
-> UniqSM (GenStgExpr 'Vanilla)
-> UniqSM (AltCon, [Id], GenStgExpr 'Vanilla)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho GenStgExpr 'Vanilla
e

unariseSumAlt UnariseEnv
rho [OutStgArg]
args (DataAlt DataCon
sumCon, [BinderP 'Vanilla]
bs, GenStgExpr 'Vanilla
e)
  = do let rho' :: UnariseEnv
rho' = [Id] -> [OutStgArg] -> UnariseEnv -> UnariseEnv
mapSumIdBinders [Id]
[BinderP 'Vanilla]
bs [OutStgArg]
args UnariseEnv
rho
       GenStgExpr 'Vanilla
e' <- UnariseEnv -> GenStgExpr 'Vanilla -> UniqSM (GenStgExpr 'Vanilla)
unariseExpr UnariseEnv
rho' GenStgExpr 'Vanilla
e
       (AltCon, [Id], GenStgExpr 'Vanilla)
-> UniqSM (AltCon, [Id], GenStgExpr 'Vanilla)
forall (m :: * -> *) a. Monad m => a -> m a
return ( Literal -> AltCon
LitAlt (LitNumType -> Integer -> Type -> Literal
LitNumber LitNumType
LitNumInt (Int -> Integer
forall a b. (Integral a, Num b) => a -> b
fromIntegral (DataCon -> Int
dataConTag DataCon
sumCon)) Type
intPrimTy), [], GenStgExpr 'Vanilla
e' )

unariseSumAlt UnariseEnv
_ [OutStgArg]
scrt GenStgAlt 'Vanilla
alt
  = String -> SDoc -> UniqSM (AltCon, [Id], GenStgExpr 'Vanilla)
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"unariseSumAlt" ([OutStgArg] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [OutStgArg]
scrt SDoc -> SDoc -> SDoc
$$ (AltCon, [Id], GenStgExpr 'Vanilla) -> SDoc
forall a. Outputable a => a -> SDoc
ppr (AltCon, [Id], GenStgExpr 'Vanilla)
GenStgAlt 'Vanilla
alt)

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

mapTupleIdBinders
  :: [InId]       -- Un-processed binders of a tuple alternative.
                  -- Can have void binders.
  -> [OutStgArg]  -- Arguments that form the tuple (after unarisation).
                  -- Can't have void args.
  -> UnariseEnv
  -> UnariseEnv
mapTupleIdBinders :: [Id] -> [OutStgArg] -> UnariseEnv -> UnariseEnv
mapTupleIdBinders [Id]
ids [OutStgArg]
args0 UnariseEnv
rho0
  = ASSERT(not (any (isVoidTy . stgArgType) args0))
    let
      ids_unarised :: [(Id, [PrimRep])]
      ids_unarised :: [(Id, [PrimRep])]
ids_unarised = (Id -> (Id, [PrimRep])) -> [Id] -> [(Id, [PrimRep])]
forall a b. (a -> b) -> [a] -> [b]
map (\Id
id -> (Id
id, HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep (Id -> Type
idType Id
id))) [Id]
ids

      map_ids :: UnariseEnv -> [(Id, [PrimRep])] -> [StgArg] -> UnariseEnv
      map_ids :: UnariseEnv -> [(Id, [PrimRep])] -> [OutStgArg] -> UnariseEnv
map_ids UnariseEnv
rho [] [OutStgArg]
_  = UnariseEnv
rho
      map_ids UnariseEnv
rho ((Id
x, [PrimRep]
x_reps) : [(Id, [PrimRep])]
xs) [OutStgArg]
args =
        let
          x_arity :: Int
x_arity = [PrimRep] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [PrimRep]
x_reps
          ([OutStgArg]
x_args, [OutStgArg]
args') =
            ASSERT(args `lengthAtLeast` x_arity)
            Int -> [OutStgArg] -> ([OutStgArg], [OutStgArg])
forall a. Int -> [a] -> ([a], [a])
splitAt Int
x_arity [OutStgArg]
args

          rho' :: UnariseEnv
rho'
            | Int
x_arity Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
1
            = ASSERT(x_args `lengthIs` 1)
              UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x (OutStgArg -> UnariseVal
UnaryVal ([OutStgArg] -> OutStgArg
forall a. [a] -> a
head [OutStgArg]
x_args))
            | Bool
otherwise
            = UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x ([OutStgArg] -> UnariseVal
MultiVal [OutStgArg]
x_args)
        in
          UnariseEnv -> [(Id, [PrimRep])] -> [OutStgArg] -> UnariseEnv
map_ids UnariseEnv
rho' [(Id, [PrimRep])]
xs [OutStgArg]
args'
    in
      UnariseEnv -> [(Id, [PrimRep])] -> [OutStgArg] -> UnariseEnv
map_ids UnariseEnv
rho0 [(Id, [PrimRep])]
ids_unarised [OutStgArg]
args0

mapSumIdBinders
  :: [InId]      -- Binder of a sum alternative (remember that sum patterns
                 -- only have one binder, so this list should be a singleton)
  -> [OutStgArg] -- Arguments that form the sum (NOT including the tag).
                 -- Can't have void args.
  -> UnariseEnv
  -> UnariseEnv

mapSumIdBinders :: [Id] -> [OutStgArg] -> UnariseEnv -> UnariseEnv
mapSumIdBinders [Id
id] [OutStgArg]
args UnariseEnv
rho0
  = ASSERT(not (any (isVoidTy . stgArgType) args))
    let
      arg_slots :: [SlotTy]
arg_slots = (PrimRep -> SlotTy) -> [PrimRep] -> [SlotTy]
forall a b. (a -> b) -> [a] -> [b]
map PrimRep -> SlotTy
primRepSlot ([PrimRep] -> [SlotTy]) -> [PrimRep] -> [SlotTy]
forall a b. (a -> b) -> a -> b
$ (OutStgArg -> [PrimRep]) -> [OutStgArg] -> [PrimRep]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap (HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep (Type -> [PrimRep])
-> (OutStgArg -> Type) -> OutStgArg -> [PrimRep]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. OutStgArg -> Type
stgArgType) [OutStgArg]
args
      id_slots :: [SlotTy]
id_slots  = (PrimRep -> SlotTy) -> [PrimRep] -> [SlotTy]
forall a b. (a -> b) -> [a] -> [b]
map PrimRep -> SlotTy
primRepSlot ([PrimRep] -> [SlotTy]) -> [PrimRep] -> [SlotTy]
forall a b. (a -> b) -> a -> b
$ HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep (Id -> Type
idType Id
id)
      layout1 :: [Int]
layout1   = [SlotTy] -> [SlotTy] -> [Int]
layoutUbxSum [SlotTy]
arg_slots [SlotTy]
id_slots
    in
      if Id -> Bool
isMultiValBndr Id
id
        then UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho0 Id
id ([OutStgArg] -> UnariseVal
MultiVal [ [OutStgArg]
args [OutStgArg] -> Int -> OutStgArg
forall a. [a] -> Int -> a
!! Int
i | Int
i <- [Int]
layout1 ])
        else ASSERT(layout1 `lengthIs` 1)
             UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho0 Id
id (OutStgArg -> UnariseVal
UnaryVal ([OutStgArg]
args [OutStgArg] -> Int -> OutStgArg
forall a. [a] -> Int -> a
!! [Int] -> Int
forall a. [a] -> a
head [Int]
layout1))

mapSumIdBinders [Id]
ids [OutStgArg]
sum_args UnariseEnv
_
  = String -> SDoc -> UnariseEnv
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"mapSumIdBinders" ([Id] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [Id]
ids SDoc -> SDoc -> SDoc
$$ [OutStgArg] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [OutStgArg]
sum_args)

-- | Build a unboxed sum term from arguments of an alternative.
--
-- Example, for (# x | #) :: (# (# #) | Int #) we call
--
--   mkUbxSum (# _ | #) [ (# #), Int ] [ voidPrimId ]
--
-- which returns
--
--   [ 1#, rubbish ]
--
mkUbxSum
  :: DataCon      -- Sum data con
  -> [Type]       -- Type arguments of the sum data con
  -> [OutStgArg]  -- Actual arguments of the alternative.
  -> [OutStgArg]  -- Final tuple arguments
mkUbxSum :: DataCon -> [Type] -> [OutStgArg] -> [OutStgArg]
mkUbxSum DataCon
dc [Type]
ty_args [OutStgArg]
args0
  = let
      (SlotTy
_ : [SlotTy]
sum_slots) = [[PrimRep]] -> [SlotTy]
ubxSumRepType ((Type -> [PrimRep]) -> [Type] -> [[PrimRep]]
forall a b. (a -> b) -> [a] -> [b]
map HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep [Type]
ty_args)
        -- drop tag slot

      tag :: Int
tag = DataCon -> Int
dataConTag DataCon
dc

      layout' :: [Int]
layout'  = [SlotTy] -> [SlotTy] -> [Int]
layoutUbxSum [SlotTy]
sum_slots ((OutStgArg -> Maybe SlotTy) -> [OutStgArg] -> [SlotTy]
forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe (Type -> Maybe SlotTy
typeSlotTy (Type -> Maybe SlotTy)
-> (OutStgArg -> Type) -> OutStgArg -> Maybe SlotTy
forall b c a. (b -> c) -> (a -> b) -> a -> c
. OutStgArg -> Type
stgArgType) [OutStgArg]
args0)
      tag_arg :: OutStgArg
tag_arg  = Literal -> OutStgArg
StgLitArg (LitNumType -> Integer -> Type -> Literal
LitNumber LitNumType
LitNumInt (Int -> Integer
forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
tag) Type
intPrimTy)
      arg_idxs :: IntMap OutStgArg
arg_idxs = [(Int, OutStgArg)] -> IntMap OutStgArg
forall a. [(Int, a)] -> IntMap a
IM.fromList (String -> [Int] -> [OutStgArg] -> [(Int, OutStgArg)]
forall a b. String -> [a] -> [b] -> [(a, b)]
zipEqual String
"mkUbxSum" [Int]
layout' [OutStgArg]
args0)

      mkTupArgs :: Int -> [SlotTy] -> IM.IntMap StgArg -> [StgArg]
      mkTupArgs :: Int -> [SlotTy] -> IntMap OutStgArg -> [OutStgArg]
mkTupArgs Int
_ [] IntMap OutStgArg
_
        = []
      mkTupArgs Int
arg_idx (SlotTy
slot : [SlotTy]
slots_left) IntMap OutStgArg
arg_map
        | Just OutStgArg
stg_arg <- Int -> IntMap OutStgArg -> Maybe OutStgArg
forall a. Int -> IntMap a -> Maybe a
IM.lookup Int
arg_idx IntMap OutStgArg
arg_map
        = OutStgArg
stg_arg OutStgArg -> [OutStgArg] -> [OutStgArg]
forall a. a -> [a] -> [a]
: Int -> [SlotTy] -> IntMap OutStgArg -> [OutStgArg]
mkTupArgs (Int
arg_idx Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
1) [SlotTy]
slots_left IntMap OutStgArg
arg_map
        | Bool
otherwise
        = SlotTy -> OutStgArg
slotRubbishArg SlotTy
slot OutStgArg -> [OutStgArg] -> [OutStgArg]
forall a. a -> [a] -> [a]
: Int -> [SlotTy] -> IntMap OutStgArg -> [OutStgArg]
mkTupArgs (Int
arg_idx Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
1) [SlotTy]
slots_left IntMap OutStgArg
arg_map

      slotRubbishArg :: SlotTy -> StgArg
      slotRubbishArg :: SlotTy -> OutStgArg
slotRubbishArg SlotTy
PtrSlot    = Id -> OutStgArg
StgVarArg Id
aBSENT_SUM_FIELD_ERROR_ID
                         -- See Note [aBSENT_SUM_FIELD_ERROR_ID] in MkCore
      slotRubbishArg SlotTy
WordSlot   = Literal -> OutStgArg
StgLitArg (LitNumType -> Integer -> Type -> Literal
LitNumber LitNumType
LitNumWord Integer
0 Type
wordPrimTy)
      slotRubbishArg SlotTy
Word64Slot = Literal -> OutStgArg
StgLitArg (LitNumType -> Integer -> Type -> Literal
LitNumber LitNumType
LitNumWord64 Integer
0 Type
word64PrimTy)
      slotRubbishArg SlotTy
FloatSlot  = Literal -> OutStgArg
StgLitArg (Rational -> Literal
LitFloat Rational
0)
      slotRubbishArg SlotTy
DoubleSlot = Literal -> OutStgArg
StgLitArg (Rational -> Literal
LitDouble Rational
0)
    in
      OutStgArg
tag_arg OutStgArg -> [OutStgArg] -> [OutStgArg]
forall a. a -> [a] -> [a]
: Int -> [SlotTy] -> IntMap OutStgArg -> [OutStgArg]
mkTupArgs Int
0 [SlotTy]
sum_slots IntMap OutStgArg
arg_idxs

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

{-
For arguments (StgArg) and binders (Id) we have two kind of unarisation:

  - When unarising function arg binders and arguments, we don't want to remove
    void binders and arguments. For example,

      f :: (# (# #), (# #) #) -> Void# -> RealWorld# -> ...
      f x y z = <body>

    Here after unarise we should still get a function with arity 3. Similarly
    in the call site we shouldn't remove void arguments:

      f (# (# #), (# #) #) voidId rw

    When unarising <body>, we extend the environment with these binders:

      x :-> MultiVal [], y :-> MultiVal [], z :-> MultiVal []

    Because their rep types are `MultiRep []` (aka. void). This means that when
    we see `x` in a function argument position, we actually replace it with a
    void argument. When we see it in a DataCon argument position, we just get
    rid of it, because DataCon applications in STG are always saturated.

  - When unarising case alternative binders we remove void binders, but we
    still update the environment the same way, because those binders may be
    used in the RHS. Example:

      case x of y {
        (# x1, x2, x3 #) -> <RHS>
      }

    We know that y can't be void, because we don't scrutinize voids, so x will
    be unarised to some number of arguments, and those arguments will have at
    least one non-void thing. So in the rho we will have something like:

      x :-> MultiVal [xu1, xu2]

    Now, after we eliminate void binders in the pattern, we get exactly the same
    number of binders, and extend rho again with these:

      x1 :-> UnaryVal xu1
      x2 :-> MultiVal [] -- x2 is void
      x3 :-> UnaryVal xu2

    Now when we see x2 in a function argument position or in return position, we
    generate void#. In constructor argument position, we just remove it.

So in short, when we have a void id,

  - We keep it if it's a lambda argument binder or
                       in argument position of an application.

  - We remove it if it's a DataCon field binder or
                         in argument position of a DataCon application.
-}

unariseArgBinder
    :: Bool -- data con arg?
    -> UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseArgBinder :: Bool -> UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseArgBinder Bool
is_con_arg UnariseEnv
rho Id
x =
  case HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep (Id -> Type
idType Id
x) of
    []
      | Bool
is_con_arg
      -> (UnariseEnv, [Id]) -> UniqSM (UnariseEnv, [Id])
forall (m :: * -> *) a. Monad m => a -> m a
return (UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x ([OutStgArg] -> UnariseVal
MultiVal []), [])
      | Bool
otherwise -- fun arg, do not remove void binders
      -> (UnariseEnv, [Id]) -> UniqSM (UnariseEnv, [Id])
forall (m :: * -> *) a. Monad m => a -> m a
return (UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x ([OutStgArg] -> UnariseVal
MultiVal []), [Id
voidArgId])

    [PrimRep
rep]
      -- Arg represented as single variable, but original type may still be an
      -- unboxed sum/tuple, e.g. (# Void# | Void# #).
      --
      -- While not unarising the binder in this case does not break any programs
      -- (because it unarises to a single variable), it triggers StgLint as we
      -- break the the post-unarisation invariant that says unboxed tuple/sum
      -- binders should vanish. See Note [Post-unarisation invariants].
      | Type -> Bool
isUnboxedSumType (Id -> Type
idType Id
x) Bool -> Bool -> Bool
|| Type -> Bool
isUnboxedTupleType (Id -> Type
idType Id
x)
      -> do Id
x' <- FastString -> Type -> UniqSM Id
mkId (String -> FastString
mkFastString String
"us") (PrimRep -> Type
primRepToType PrimRep
rep)
            (UnariseEnv, [Id]) -> UniqSM (UnariseEnv, [Id])
forall (m :: * -> *) a. Monad m => a -> m a
return (UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x ([OutStgArg] -> UnariseVal
MultiVal [Id -> OutStgArg
StgVarArg Id
x']), [Id
x'])
      | Bool
otherwise
      -> (UnariseEnv, [Id]) -> UniqSM (UnariseEnv, [Id])
forall (m :: * -> *) a. Monad m => a -> m a
return (UnariseEnv
rho, [Id
x])

    [PrimRep]
reps -> do
      [Id]
xs <- FastString -> [Type] -> UniqSM [Id]
mkIds (String -> FastString
mkFastString String
"us") ((PrimRep -> Type) -> [PrimRep] -> [Type]
forall a b. (a -> b) -> [a] -> [b]
map PrimRep -> Type
primRepToType [PrimRep]
reps)
      (UnariseEnv, [Id]) -> UniqSM (UnariseEnv, [Id])
forall (m :: * -> *) a. Monad m => a -> m a
return (UnariseEnv -> Id -> UnariseVal -> UnariseEnv
extendRho UnariseEnv
rho Id
x ([OutStgArg] -> UnariseVal
MultiVal ((Id -> OutStgArg) -> [Id] -> [OutStgArg]
forall a b. (a -> b) -> [a] -> [b]
map Id -> OutStgArg
StgVarArg [Id]
xs)), [Id]
xs)

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

-- | MultiVal a function argument. Never returns an empty list.
unariseFunArg :: UnariseEnv -> StgArg -> [StgArg]
unariseFunArg :: UnariseEnv -> OutStgArg -> [OutStgArg]
unariseFunArg UnariseEnv
rho (StgVarArg Id
x) =
  case UnariseEnv -> Id -> Maybe UnariseVal
forall a. VarEnv a -> Id -> Maybe a
lookupVarEnv UnariseEnv
rho Id
x of
    Just (MultiVal [])  -> [OutStgArg
voidArg]   -- NB: do not remove void args
    Just (MultiVal [OutStgArg]
as)  -> [OutStgArg]
as
    Just (UnaryVal OutStgArg
arg) -> [OutStgArg
arg]
    Maybe UnariseVal
Nothing             -> [Id -> OutStgArg
StgVarArg Id
x]
unariseFunArg UnariseEnv
_ OutStgArg
arg = [OutStgArg
arg]

unariseFunArgs :: UnariseEnv -> [StgArg] -> [StgArg]
unariseFunArgs :: UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseFunArgs = (OutStgArg -> [OutStgArg]) -> [OutStgArg] -> [OutStgArg]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap ((OutStgArg -> [OutStgArg]) -> [OutStgArg] -> [OutStgArg])
-> (UnariseEnv -> OutStgArg -> [OutStgArg])
-> UnariseEnv
-> [OutStgArg]
-> [OutStgArg]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. UnariseEnv -> OutStgArg -> [OutStgArg]
unariseFunArg

unariseFunArgBinders :: UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseFunArgBinders :: UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseFunArgBinders UnariseEnv
rho [Id]
xs = ([[Id]] -> [Id]) -> (UnariseEnv, [[Id]]) -> (UnariseEnv, [Id])
forall (p :: * -> * -> *) b c a.
Bifunctor p =>
(b -> c) -> p a b -> p a c
second [[Id]] -> [Id]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat ((UnariseEnv, [[Id]]) -> (UnariseEnv, [Id]))
-> UniqSM (UnariseEnv, [[Id]]) -> UniqSM (UnariseEnv, [Id])
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id]))
-> UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [[Id]])
forall (m :: * -> *) acc x y.
Monad m =>
(acc -> x -> m (acc, y)) -> acc -> [x] -> m (acc, [y])
mapAccumLM UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseFunArgBinder UnariseEnv
rho [Id]
xs

-- Result list of binders is never empty
unariseFunArgBinder :: UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseFunArgBinder :: UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseFunArgBinder = Bool -> UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseArgBinder Bool
False

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

-- | MultiVal a DataCon argument. Returns an empty list when argument is void.
unariseConArg :: UnariseEnv -> InStgArg -> [OutStgArg]
unariseConArg :: UnariseEnv -> OutStgArg -> [OutStgArg]
unariseConArg UnariseEnv
rho (StgVarArg Id
x) =
  case UnariseEnv -> Id -> Maybe UnariseVal
forall a. VarEnv a -> Id -> Maybe a
lookupVarEnv UnariseEnv
rho Id
x of
    Just (UnaryVal OutStgArg
arg) -> [OutStgArg
arg]
    Just (MultiVal [OutStgArg]
as) -> [OutStgArg]
as      -- 'as' can be empty
    Maybe UnariseVal
Nothing
      | Type -> Bool
isVoidTy (Id -> Type
idType Id
x) -> [] -- e.g. C realWorld#
                                  -- Here realWorld# is not in the envt, but
                                  -- is a void, and so should be eliminated
      | Bool
otherwise -> [Id -> OutStgArg
StgVarArg Id
x]
unariseConArg UnariseEnv
_ arg :: OutStgArg
arg@(StgLitArg Literal
lit) =
    ASSERT(not (isVoidTy (literalType lit)))  -- We have no void literals
    [OutStgArg
arg]

unariseConArgs :: UnariseEnv -> [InStgArg] -> [OutStgArg]
unariseConArgs :: UnariseEnv -> [OutStgArg] -> [OutStgArg]
unariseConArgs = (OutStgArg -> [OutStgArg]) -> [OutStgArg] -> [OutStgArg]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap ((OutStgArg -> [OutStgArg]) -> [OutStgArg] -> [OutStgArg])
-> (UnariseEnv -> OutStgArg -> [OutStgArg])
-> UnariseEnv
-> [OutStgArg]
-> [OutStgArg]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. UnariseEnv -> OutStgArg -> [OutStgArg]
unariseConArg

unariseConArgBinders :: UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseConArgBinders :: UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [Id])
unariseConArgBinders UnariseEnv
rho [Id]
xs = ([[Id]] -> [Id]) -> (UnariseEnv, [[Id]]) -> (UnariseEnv, [Id])
forall (p :: * -> * -> *) b c a.
Bifunctor p =>
(b -> c) -> p a b -> p a c
second [[Id]] -> [Id]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat ((UnariseEnv, [[Id]]) -> (UnariseEnv, [Id]))
-> UniqSM (UnariseEnv, [[Id]]) -> UniqSM (UnariseEnv, [Id])
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> (UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id]))
-> UnariseEnv -> [Id] -> UniqSM (UnariseEnv, [[Id]])
forall (m :: * -> *) acc x y.
Monad m =>
(acc -> x -> m (acc, y)) -> acc -> [x] -> m (acc, [y])
mapAccumLM UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseConArgBinder UnariseEnv
rho [Id]
xs

-- Different from `unariseFunArgBinder`: result list of binders may be empty.
-- See DataCon applications case in Note [Post-unarisation invariants].
unariseConArgBinder :: UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseConArgBinder :: UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseConArgBinder = Bool -> UnariseEnv -> Id -> UniqSM (UnariseEnv, [Id])
unariseArgBinder Bool
True

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

mkIds :: FastString -> [UnaryType] -> UniqSM [Id]
mkIds :: FastString -> [Type] -> UniqSM [Id]
mkIds FastString
fs [Type]
tys = (Type -> UniqSM Id) -> [Type] -> UniqSM [Id]
forall (t :: * -> *) (m :: * -> *) a b.
(Traversable t, Monad m) =>
(a -> m b) -> t a -> m (t b)
mapM (FastString -> Type -> UniqSM Id
mkId FastString
fs) [Type]
tys

mkId :: FastString -> UnaryType -> UniqSM Id
mkId :: FastString -> Type -> UniqSM Id
mkId = FastString -> Type -> UniqSM Id
forall (m :: * -> *). MonadUnique m => FastString -> Type -> m Id
mkSysLocalOrCoVarM

isMultiValBndr :: Id -> Bool
isMultiValBndr :: Id -> Bool
isMultiValBndr Id
id
  | [PrimRep
_] <- HasDebugCallStack => Type -> [PrimRep]
Type -> [PrimRep]
typePrimRep (Id -> Type
idType Id
id)
  = Bool
False
  | Bool
otherwise
  = Bool
True

isUnboxedSumBndr :: Id -> Bool
isUnboxedSumBndr :: Id -> Bool
isUnboxedSumBndr = Type -> Bool
isUnboxedSumType (Type -> Bool) -> (Id -> Type) -> Id -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> Type
idType

isUnboxedTupleBndr :: Id -> Bool
isUnboxedTupleBndr :: Id -> Bool
isUnboxedTupleBndr = Type -> Bool
isUnboxedTupleType (Type -> Bool) -> (Id -> Type) -> Id -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> Type
idType

mkTuple :: [StgArg] -> StgExpr
mkTuple :: [OutStgArg] -> GenStgExpr 'Vanilla
mkTuple [OutStgArg]
args = DataCon -> [OutStgArg] -> [Type] -> GenStgExpr 'Vanilla
forall (pass :: StgPass).
DataCon -> [OutStgArg] -> [Type] -> GenStgExpr pass
StgConApp (Boxity -> Int -> DataCon
tupleDataCon Boxity
Unboxed ([OutStgArg] -> Int
forall (t :: * -> *) a. Foldable t => t a -> Int
length [OutStgArg]
args)) [OutStgArg]
args ((OutStgArg -> Type) -> [OutStgArg] -> [Type]
forall a b. (a -> b) -> [a] -> [b]
map OutStgArg -> Type
stgArgType [OutStgArg]
args)

tagAltTy :: AltType
tagAltTy :: AltType
tagAltTy = PrimRep -> AltType
PrimAlt PrimRep
IntRep

tagTy :: Type
tagTy :: Type
tagTy = Type
intPrimTy

voidArg :: StgArg
voidArg :: OutStgArg
voidArg = Id -> OutStgArg
StgVarArg Id
voidPrimId

mkDefaultLitAlt :: [StgAlt] -> [StgAlt]
-- We have an exhauseive list of literal alternatives
--    1# -> e1
--    2# -> e2
-- Since they are exhaustive, we can replace one with DEFAULT, to avoid
-- generating a final test. Remember, the DEFAULT comes first if it exists.
mkDefaultLitAlt :: [GenStgAlt 'Vanilla] -> [GenStgAlt 'Vanilla]
mkDefaultLitAlt [] = String -> SDoc -> [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"elimUbxSumExpr.mkDefaultAlt" (String -> SDoc
text String
"Empty alts")
mkDefaultLitAlt alts :: [GenStgAlt 'Vanilla]
alts@((AltCon
DEFAULT, [BinderP 'Vanilla]
_, GenStgExpr 'Vanilla
_) : [GenStgAlt 'Vanilla]
_) = [GenStgAlt 'Vanilla]
alts
mkDefaultLitAlt ((LitAlt{}, [], GenStgExpr 'Vanilla
rhs) : [GenStgAlt 'Vanilla]
alts) = (AltCon
DEFAULT, [], GenStgExpr 'Vanilla
rhs) (AltCon, [Id], GenStgExpr 'Vanilla)
-> [(AltCon, [Id], GenStgExpr 'Vanilla)]
-> [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall a. a -> [a] -> [a]
: [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts
mkDefaultLitAlt [GenStgAlt 'Vanilla]
alts = String -> SDoc -> [(AltCon, [Id], GenStgExpr 'Vanilla)]
forall a. HasCallStack => String -> SDoc -> a
pprPanic String
"mkDefaultLitAlt" (String -> SDoc
text String
"Not a lit alt:" SDoc -> SDoc -> SDoc
<+> [(AltCon, [Id], GenStgExpr 'Vanilla)] -> SDoc
forall a. Outputable a => a -> SDoc
ppr [(AltCon, [Id], GenStgExpr 'Vanilla)]
[GenStgAlt 'Vanilla]
alts)