Revert "Adds data instances, and denesting for ByteArray#"

This reverts commit 8e558717285d306442c2464421ecfaf42354e946.

24 files changed, 185 insertions, 263 deletions

diff --git a/compiler/GHC/Builtin/PrimOps.hs b/compiler/GHC/Builtin/PrimOps.hs
index 5766caa998..ecd9da0ac2 100644
--- a/compiler/GHC/Builtin/PrimOps.hs
+++ b/compiler/GHC/Builtin/PrimOps.hs
@@ -5,8 +5,6 @@
 -}
 
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE StandaloneDeriving #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Builtin.PrimOps (
         PrimOp(..), PrimOpVecCat(..), allThePrimOps,
@@ -55,7 +53,6 @@ import GHC.Unit.Types    ( Unit )
 import GHC.Utils.Outputable
 
 import GHC.Data.FastString
-import Data.Data (Data)
 
 {-
 ************************************************************************
@@ -76,8 +73,7 @@ These are in \tr{state-interface.verb} order.
 #include "primop-tag.hs-incl"
 primOpTag _ = error "primOpTag: unknown primop"
 
-deriving instance Data PrimOp
-deriving instance Data PrimOpVecCat
+
 instance Eq PrimOp where
     op1 == op2 = primOpTag op1 == primOpTag op2
 
diff --git a/compiler/GHC/Builtin/Types.hs b/compiler/GHC/Builtin/Types.hs
index bbabc6e241..21c579460a 100644
--- a/compiler/GHC/Builtin/Types.hs
+++ b/compiler/GHC/Builtin/Types.hs
@@ -180,7 +180,7 @@ import GHC.Unit.Module        ( Module )
 import GHC.Core.Type
 import qualified GHC.Core.TyCo.Rep as TyCoRep (Type(TyConApp))
 import GHC.Core.TyCo.Rep (RuntimeRepType)
-import GHC.Types.RepType (runtimeRepPrimRep, slotPrimRep, ubxSumRepType)
+import GHC.Types.RepType ()
 import GHC.Core.DataCon
 import GHC.Core.ConLike
 import GHC.Core.TyCon
diff --git a/compiler/GHC/Cmm/CLabel.hs b/compiler/GHC/Cmm/CLabel.hs
index 2e9c283241..b718b73f30 100644
--- a/compiler/GHC/Cmm/CLabel.hs
+++ b/compiler/GHC/Cmm/CLabel.hs
@@ -9,7 +9,6 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 
 module GHC.Cmm.CLabel (
@@ -157,7 +156,6 @@ import GHC.Types.Unique.Set
 import GHC.Utils.Misc
 import GHC.Core.Ppr ( {- instances -} )
 import GHC.Types.SrcLoc
-import Data.Data (Data)
 
 -- -----------------------------------------------------------------------------
 -- The CLabel type
@@ -292,7 +290,7 @@ data CLabel
   | LargeBitmapLabel
         {-# UNPACK #-} !Unique
 
-  deriving (Eq,Data)
+  deriving Eq
 
 instance Show CLabel where
   show = showPprUnsafe . pprDebugCLabel genericPlatform
@@ -302,7 +300,7 @@ data ModuleLabelKind
     | MLK_InitializerArray
     | MLK_Finalizer String
     | MLK_FinalizerArray
-    deriving (Eq, Ord, Data)
+    deriving (Eq, Ord)
 
 instance Outputable ModuleLabelKind where
     ppr MLK_InitializerArray = text "init_arr"
@@ -336,7 +334,7 @@ isTickyLabel _ = False
 -- for why extern declaration are needed at all.
 newtype NeedExternDecl
    = NeedExternDecl Bool
-   deriving (Ord,Eq, Data)
+   deriving (Ord,Eq)
 
 -- This is laborious, but necessary. We can't derive Ord because
 -- Unique doesn't have an Ord instance. Note nonDetCmpUnique in the
@@ -443,7 +441,7 @@ data ForeignLabelSource
    --   destination module.
    | ForeignLabelInThisPackage
 
-   deriving (Eq, Ord, Data)
+   deriving (Eq, Ord)
 
 
 -- | For debugging problems with the CLabel representation.
@@ -472,7 +470,7 @@ pprDebugCLabel platform lbl = pprCLabel platform AsmStyle lbl <> parens extra
 data TickyIdInfo
   = TickyRednCounts           -- ^ Used for dynamic allocations
   | TickyInferedTag !Unique    -- ^ Used to track dynamic hits of tag inference.
-  deriving (Eq,Show, Data)
+  deriving (Eq,Show)
 
 instance Outputable TickyIdInfo where
     ppr TickyRednCounts = text "ct_rdn"
@@ -521,12 +519,12 @@ data IdLabelInfo
                         -- instead of a closure entry-point.
                         -- See Note [Proc-point local block entry-points].
 
-  deriving (Eq, Ord, Data)
+  deriving (Eq, Ord)
 
 -- | Which module is the info table from, and which number was it.
 data ConInfoTableLocation = UsageSite Module Int
                           | DefinitionSite
-                              deriving (Eq, Ord, Data)
+                              deriving (Eq, Ord)
 
 instance Outputable ConInfoTableLocation where
   ppr (UsageSite m n) = text "Loc(" <> ppr n <> text "):" <+> ppr m
@@ -564,7 +562,7 @@ data RtsLabelInfo
   | RtsApFast            NonDetFastString    -- ^ _fast versions of generic apply
   | RtsSlowFastTickyCtr String
 
-  deriving (Eq,Ord, Data)
+  deriving (Eq,Ord)
 
 
 -- | What type of Cmm label we're dealing with.
@@ -579,7 +577,7 @@ data CmmLabelInfo
   | CmmCode                     -- ^ misc rts code
   | CmmClosure                  -- ^ closures eg CHARLIKE_closure
   | CmmPrimCall                 -- ^ a prim call to some hand written Cmm code
-  deriving (Eq, Ord, Data)
+  deriving (Eq, Ord)
 
 data DynamicLinkerLabelInfo
   = CodeStub                    -- MachO: Lfoo$stub, ELF: foo@plt
@@ -587,7 +585,7 @@ data DynamicLinkerLabelInfo
   | GotSymbolPtr                -- ELF: foo@got
   | GotSymbolOffset             -- ELF: foo@gotoff
 
-  deriving (Eq, Ord, Data)
+  deriving (Eq, Ord)
 
 
 -- -----------------------------------------------------------------------------
@@ -825,7 +823,7 @@ data InfoProvEnt = InfoProvEnt
                                -- Origin module
                                , infoTableProv :: !(Maybe (RealSrcSpan, String)) }
                                -- Position and information about the info table
-                               deriving (Eq, Ord, Data)
+                               deriving (Eq, Ord)
 
 instance OutputableP Platform InfoProvEnt where
   pdoc platform (InfoProvEnt clabel _ _ _ _) = pdoc platform clabel
diff --git a/compiler/GHC/Cmm/Dataflow/Label.hs b/compiler/GHC/Cmm/Dataflow/Label.hs
index d5c4270a81..a9a74fd50e 100644
--- a/compiler/GHC/Cmm/Dataflow/Label.hs
+++ b/compiler/GHC/Cmm/Dataflow/Label.hs
@@ -3,8 +3,6 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Cmm.Dataflow.Label
     ( Label
@@ -24,7 +22,6 @@ import GHC.Cmm.Dataflow.Collections
 
 import GHC.Types.Unique (Uniquable(..))
 import GHC.Data.TrieMap
-import Data.Data (Data)
 
 
 -----------------------------------------------------------------------------
@@ -32,7 +29,7 @@ import Data.Data (Data)
 -----------------------------------------------------------------------------
 
 newtype Label = Label { lblToUnique :: Int }
-  deriving (Eq, Ord, Data)
+  deriving (Eq, Ord)
 
 mkHooplLabel :: Int -> Label
 mkHooplLabel = Label
diff --git a/compiler/GHC/Cmm/Expr.hs b/compiler/GHC/Cmm/Expr.hs
index 449f28d82e..212316b68d 100644
--- a/compiler/GHC/Cmm/Expr.hs
+++ b/compiler/GHC/Cmm/Expr.hs
@@ -4,7 +4,6 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE UndecidableInstances #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Cmm.Expr
     ( CmmExpr(..), cmmExprType, cmmExprWidth, cmmExprAlignment, maybeInvertCmmExpr
@@ -57,7 +56,6 @@ import qualified Data.Set as Set
 import Numeric ( fromRat )
 
 import GHC.Types.Basic (Alignment, mkAlignment, alignmentOf)
-import Data.Data
 
 -----------------------------------------------------------------------------
 --              CmmExpr
@@ -78,7 +76,7 @@ data CmmExpr
         --        ** is shorthand only, meaning **
         -- CmmMachOp (MO_Add rep) [x, CmmLit (CmmInt (fromIntegral i) rep)]
         --      where rep = typeWidth (cmmRegType reg)
-  deriving (Show, Data)
+  deriving Show
 
 instance Eq CmmExpr where       -- Equality ignores the types
   CmmLit l1          == CmmLit l2          = l1==l2
@@ -93,7 +91,7 @@ instance OutputableP Platform CmmExpr where
     pdoc = pprExpr
 
 data AlignmentSpec = NaturallyAligned | Unaligned
-  deriving (Eq, Ord, Show, Data)
+  deriving (Eq, Ord, Show)
 
 -- | A stack area is either the stack slot where a variable is spilled
 -- or the stack space where function arguments and results are passed.
@@ -101,7 +99,7 @@ data Area
   = Old            -- See Note [Old Area]
   | Young {-# UNPACK #-} !BlockId  -- Invariant: must be a continuation BlockId
                    -- See Note [Continuation BlockIds] in GHC.Cmm.Node.
-  deriving (Eq, Ord, Show, Data)
+  deriving (Eq, Ord, Show)
 
 instance Outputable Area where
     ppr e = pprArea e
@@ -232,7 +230,7 @@ data CmmLit
                      -- During the stack-layout pass, CmmHighStackMark
                      -- is replaced by a CmmInt for the actual number
                      -- of bytes used
-  deriving (Eq, Show,Data)
+  deriving (Eq, Show)
 
 instance OutputableP Platform CmmLit where
     pdoc = pprLit
diff --git a/compiler/GHC/Cmm/MachOp.hs b/compiler/GHC/Cmm/MachOp.hs
index f4be3ef1bf..0bd3ac1111 100644
--- a/compiler/GHC/Cmm/MachOp.hs
+++ b/compiler/GHC/Cmm/MachOp.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Cmm.MachOp
     ( MachOp(..)
@@ -34,7 +33,6 @@ import GHC.Prelude
 import GHC.Platform
 import GHC.Cmm.Type
 import GHC.Utils.Outputable
-import Data.Data (Data)
 
 -----------------------------------------------------------------------------
 --              MachOp
@@ -157,7 +155,7 @@ data MachOp
 
   -- Alignment check (for -falignment-sanitisation)
   | MO_AlignmentCheck Int Width
-  deriving (Eq, Show, Data)
+  deriving (Eq, Show)
 
 pprMachOp :: MachOp -> SDoc
 pprMachOp mo = text (show mo)
diff --git a/compiler/GHC/Cmm/Reg.hs b/compiler/GHC/Cmm/Reg.hs
index 720b978b7d..6c94ecb2eb 100644
--- a/compiler/GHC/Cmm/Reg.hs
+++ b/compiler/GHC/Cmm/Reg.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Cmm.Reg
     ( -- * Cmm Registers
@@ -25,7 +24,6 @@ import GHC.Platform
 import GHC.Utils.Outputable
 import GHC.Types.Unique
 import GHC.Cmm.Type
-import Data.Data (Data)
 
 -----------------------------------------------------------------------------
 --              Cmm registers
@@ -34,7 +32,7 @@ import Data.Data (Data)
 data CmmReg
   = CmmLocal  {-# UNPACK #-} !LocalReg
   | CmmGlobal GlobalReg
-  deriving( Eq, Ord, Show, Data )
+  deriving( Eq, Ord, Show )
 
 instance Outputable CmmReg where
     ppr e = pprReg e
@@ -62,7 +60,7 @@ data LocalReg
     -- ^ Parameters:
     --   1. Identifier
     --   2. Type
-  deriving (Show, Data)
+  deriving Show
 
 instance Eq LocalReg where
   (LocalReg u1 _) == (LocalReg u2 _) = u1 == u2
@@ -130,7 +128,7 @@ account. However it is still used in UserOfRegs/DefinerOfRegs and
 there are likely still bugs there, beware!
 -}
 
-data VGcPtr = VGcPtr | VNonGcPtr deriving( Eq, Show, Data )
+data VGcPtr = VGcPtr | VNonGcPtr deriving( Eq, Show )
 
 data GlobalReg
   -- Argument and return registers
@@ -193,7 +191,7 @@ data GlobalReg
   -- from platform to platform (see module PositionIndependentCode).
   | PicBaseReg
 
-  deriving( Show, Data )
+  deriving( Show )
 
 instance Eq GlobalReg where
    VanillaReg i _ == VanillaReg j _ = i==j -- Ignore type when seeking clashes
diff --git a/compiler/GHC/Cmm/Type.hs b/compiler/GHC/Cmm/Type.hs
index 52308bdde6..ec000a3c47 100644
--- a/compiler/GHC/Cmm/Type.hs
+++ b/compiler/GHC/Cmm/Type.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE DeriveDataTypeable #-}
 module GHC.Cmm.Type
     ( CmmType   -- Abstract
     , b8, b16, b32, b64, b128, b256, b512, f32, f64, bWord, bHalfWord, gcWord
@@ -41,7 +40,6 @@ import GHC.Utils.Panic
 
 import Data.Word
 import Data.Int
-import Data.Data (Data)
 
 -----------------------------------------------------------------------------
 --              CmmType
@@ -55,14 +53,14 @@ import Data.Data (Data)
 
 data CmmType    -- The important one!
   = CmmType CmmCat !Width
-  deriving (Show,Data)
+  deriving Show
 
 data CmmCat                -- "Category" (not exported)
    = GcPtrCat              -- GC pointer
    | BitsCat               -- Non-pointer
    | FloatCat              -- Float
    | VecCat Length CmmCat  -- Vector
-   deriving( Eq, Show, Data)
+   deriving( Eq, Show )
         -- See Note [Signed vs unsigned] at the end
 
 instance Outputable CmmType where
@@ -184,7 +182,7 @@ data Width
   | W128
   | W256
   | W512
-  deriving (Eq, Ord, Show, Data)
+  deriving (Eq, Ord, Show)
 
 instance Outputable Width where
    ppr rep = text (show rep)
diff --git a/compiler/GHC/CmmToAsm/X86/CodeGen.hs b/compiler/GHC/CmmToAsm/X86/CodeGen.hs
index ac285f864c..9861177c3a 100644
--- a/compiler/GHC/CmmToAsm/X86/CodeGen.hs
+++ b/compiler/GHC/CmmToAsm/X86/CodeGen.hs
@@ -92,7 +92,6 @@ import Data.Maybe
 import Data.Word
 
 import qualified Data.Map as M
-import GHC.Hs.Dump (showAstDataFull)
 
 is32BitPlatform :: NatM Bool
 is32BitPlatform = do
@@ -1238,7 +1237,7 @@ getRegister' platform _ (CmmLit lit)
 
 getRegister' platform _ other
     | isVecExpr other  = needLlvm
-    | otherwise        = pprPanic "getRegister'(x86)" (pdoc platform other $$ text (show other))
+    | otherwise        = pprPanic "getRegister(x86)" (pdoc platform other)
 
 
 intLoadCode :: (Operand -> Operand -> Instr) -> CmmExpr
diff --git a/compiler/GHC/CoreToStg.hs b/compiler/GHC/CoreToStg.hs
index 51fc887d8d..6dd7a25f06 100644
--- a/compiler/GHC/CoreToStg.hs
+++ b/compiler/GHC/CoreToStg.hs
@@ -34,7 +34,6 @@ import GHC.Stg.Debug
 import GHC.Stg.Utils
 
 import GHC.Types.RepType
-import GHC.Types.Rep.Virtual (isVirtualTyCon, isVirtualDataCon)
 import GHC.Types.Id.Make ( coercionTokenId )
 import GHC.Types.Id
 import GHC.Types.Id.Info
@@ -729,13 +728,13 @@ mkTopStgRhs dflags this_mod ccs bndr (PreStgRhs bndrs rhs)
   = -- CorePrep does this right, but just to make sure
     assertPpr (not (isUnboxedTupleDataCon con || isUnboxedSumDataCon con))
               (ppr bndr $$ ppr con $$ ppr args) $
-  -- if isVirtualDataCon con
-  --   then
-  --         ( StgRhsClosure noExtFieldSilent
-  --                   all_cafs_ccs
-  --                   upd_flag [] (virtual_arg args)
-  --         , ccs )
-    -- else
+  if isVirtualDataCon con
+    then
+          ( StgRhsClosure noExtFieldSilent
+                    all_cafs_ccs
+                    upd_flag [] (virtual_arg args)
+          , ccs )
+    else
       ( StgRhsCon dontCareCCS con mn ticks args, ccs )
 
   -- Otherwise it's a CAF, see Note [Cost-centre initialization plan].
diff --git a/compiler/GHC/Stg/InferTags.hs b/compiler/GHC/Stg/InferTags.hs
index eb2c777c30..3b160f7c38 100644
--- a/compiler/GHC/Stg/InferTags.hs
+++ b/compiler/GHC/Stg/InferTags.hs
@@ -17,8 +17,7 @@ import GHC.Types.Name
 import GHC.Stg.Syntax
 import GHC.Types.Basic ( CbvMark (..) )
 import GHC.Types.Unique.Supply (mkSplitUniqSupply)
-import GHC.Types.RepType (dataConRuntimeRepStrictness)
-import GHC.Types.Rep.Virtual (isVirtualDataCon)
+import GHC.Types.RepType (dataConRuntimeRepStrictness, isVirtualTyCon, isVirtualDataCon)
 import GHC.Core (AltCon(..))
 import Data.List (mapAccumL)
 import GHC.Utils.Outputable
diff --git a/compiler/GHC/Stg/InferTags/Rewrite.hs b/compiler/GHC/Stg/InferTags/Rewrite.hs
index d2d0bbeb2f..2b78089a88 100644
--- a/compiler/GHC/Stg/InferTags/Rewrite.hs
+++ b/compiler/GHC/Stg/InferTags/Rewrite.hs
@@ -425,6 +425,7 @@ rewriteApp :: InferStgExpr -> RM TgStgExpr
 rewriteApp (StgApp f []) = do
     f' <- rewriteId f
     return $! StgApp f' []
+
 rewriteApp (StgApp f args)
     -- pprTrace "rewriteAppOther" (ppr f <+> ppr args) False
     -- = undefined
diff --git a/compiler/GHC/StgToCmm.hs-boot b/compiler/GHC/StgToCmm.hs-boot
index 023c94f48b..7e7473b18f 100644
--- a/compiler/GHC/StgToCmm.hs-boot
+++ b/compiler/GHC/StgToCmm.hs-boot
@@ -13,14 +13,61 @@
 
 module GHC.StgToCmm ( cgTopRhs ) where
 
-import GHC.Prelude as Prelude ()
+import GHC.Prelude as Prelude
 
+import GHC.StgToCmm.Prof (initCostCentres, ldvEnter)
 import GHC.StgToCmm.Monad
+import GHC.StgToCmm.Env
+import GHC.StgToCmm.Bind
+import GHC.StgToCmm.Layout
+import GHC.StgToCmm.Utils
+import GHC.StgToCmm.Closure
+import GHC.StgToCmm.Config
+import GHC.StgToCmm.Hpc
+import GHC.StgToCmm.Ticky
+import GHC.StgToCmm.Types (ModuleLFInfos)
+
+import GHC.Cmm
+import GHC.Cmm.Utils
+import GHC.Cmm.CLabel
+import GHC.Cmm.Graph
 
 import GHC.Stg.Syntax
 
+import GHC.Types.CostCentre
+import GHC.Types.IPE
+import GHC.Types.HpcInfo
 import GHC.Types.Id
+import GHC.Types.Id.Info
+import GHC.Types.RepType
 import GHC.Types.Basic
+import GHC.Types.Var.Set ( isEmptyDVarSet )
+import GHC.Types.Unique.FM
+import GHC.Types.Name.Env
+
+import GHC.Core.DataCon
+import GHC.Core.TyCon
+import GHC.Core.Multiplicity
+
+import GHC.Unit.Module
+
+import GHC.Utils.Error
+import GHC.Utils.Outputable
+import GHC.Utils.Panic.Plain
+import GHC.Utils.Logger
+
+import GHC.Utils.TmpFs
+
+import GHC.Data.Stream
+import GHC.Data.OrdList
+import GHC.Types.Unique.Map
+
+import Control.Monad (when,void, forM_)
+import GHC.Utils.Misc
+import System.IO.Unsafe
+import qualified Data.ByteString as BS
+import Data.IORef
+import GHC.Utils.Panic (assertPpr)
 
 cgTopRhs :: StgToCmmConfig -> RecFlag -> Id -> CgStgRhs -> (CgIdInfo, FCode ())
         -- The Id is passed along for setting up a binding...
diff --git a/compiler/GHC/StgToCmm/Bind.hs b/compiler/GHC/StgToCmm/Bind.hs
index 033fa9387f..a97ae084c0 100644
--- a/compiler/GHC/StgToCmm/Bind.hs
+++ b/compiler/GHC/StgToCmm/Bind.hs
@@ -65,7 +65,7 @@ import GHC.Data.List.SetOps
 
 import Control.Monad
 import GHC.Utils.Trace
-import GHC.Types.Rep.Virtual (isVirtualDataCon, virtualDataConType, VirtualConType (..))
+import GHC.Types.RepType (isVirtualDataCon)
 
 ------------------------------------------------------------------------
 --              Top-level bindings
@@ -108,21 +108,6 @@ cgTopRhsClosure platform rec id ccs upd_flag args body =
     = do
          cg_info <- getCgIdInfo f
          emitDataCon closure_label indStaticInfoTable ccs [unLit (idInfoToAmode cg_info)]
-    | StgConApp con _ [StgVarArg x] _ <- body
-    , null args
-    , vcon <- virtualDataConType con
-    -- Boxed types we can just compile to a indirection
-    , vcon /= NonVirtual
-    = do
-         cg_info <- getCgIdInfo x
-         let !payload = case vcon of
-                VirtualBoxed -> unLit (idInfoToAmode cg_info)
-                VirtualUnboxedHeap ->
-                  pprPanic "top level unboxed thing" empty $
-                  cmmOffsetLit (unLit (idInfoToAmode cg_info)) 1
-                NonVirtual -> panic "impossible" -- checked in the guard
-
-         emitDataCon closure_label indStaticInfoTable ccs [payload]
 
   gen_code lf_info _closure_label
    = do { profile <- getProfile
@@ -309,7 +294,7 @@ mkRhsClosure    profile _ _check_tags bndr _cc
   , StgApp selectee [{-no args-}] <- strip sel_expr
   , the_fv == scrutinee                -- Scrutinee is the only free variable
 
-  -- Virtual data cons look like selectors but shouldn't be evaluated by the RTS.
+  -- Virtual data cons just return themselves.
   , not $ isVirtualDataCon con
 
   , let (_, _, params_w_offsets) = mkVirtConstrOffsets profile (addIdReps (assertNonVoidIds params))
diff --git a/compiler/GHC/StgToCmm/Closure.hs b/compiler/GHC/StgToCmm/Closure.hs
index 77c3e6a70f..87d242138d 100644
--- a/compiler/GHC/StgToCmm/Closure.hs
+++ b/compiler/GHC/StgToCmm/Closure.hs
@@ -112,12 +112,10 @@ import GHC.Utils.Trace (pprTrace)
 -- module need to have access to them as well
 
 data CgLoc
-  = CmmLoc { cgl_cmm :: CmmExpr }      -- A stable CmmExpr; that is, one not mentioning
+  = CmmLoc CmmExpr      -- A stable CmmExpr; that is, one not mentioning
                         -- Hp, so that it remains valid across calls
 
-  | LneLoc { cgl_lne_block :: BlockId
-           , cgl_lne_regs :: [LocalReg] }
-        -- A join point
+  | LneLoc BlockId [LocalReg]             -- A join point
         -- A join point (= let-no-escape) should only
         -- be tail-called, and in a saturated way.
         -- To tail-call it, assign to these locals,
diff --git a/compiler/GHC/StgToCmm/DataCon.hs b/compiler/GHC/StgToCmm/DataCon.hs
index 2c9071129d..199cfe0ba4 100644
--- a/compiler/GHC/StgToCmm/DataCon.hs
+++ b/compiler/GHC/StgToCmm/DataCon.hs
@@ -10,7 +10,6 @@
 -- (c) The University of Glasgow 2004-2006
 --
 -----------------------------------------------------------------------------
-{-# LANGUAGE NamedFieldPuns #-}
 
 module GHC.StgToCmm.DataCon (
         cgTopRhsCon, buildDynCon, bindConArgs
@@ -44,8 +43,7 @@ import GHC.Types.Id
 import {-# SOURCE #-} GHC.StgToCmm.Bind
 import GHC.Types.Id.Info( CafInfo( NoCafRefs ) )
 import GHC.Types.Name (isInternalName)
-import GHC.Types.RepType (countConRepArgs)
-import GHC.Types.Rep.Virtual (isVirtualDataCon, VirtualConType(..), virtualDataConType)
+import GHC.Types.RepType (countConRepArgs, isVirtualTyCon, virtualDataConType, VirtualConType(..), isVirtualDataCon)
 import GHC.Types.Literal
 import GHC.Builtin.Utils
 import GHC.Utils.Panic
@@ -56,9 +54,10 @@ import GHC.Utils.Monad (mapMaybeM)
 import Control.Monad
 import Data.Char
 import GHC.StgToCmm.Config (stgToCmmPlatform)
-import GHC.StgToCmm.TagCheck (checkConArgsStatic, checkConArgsDyn, emitTagAssertionId)
+import GHC.StgToCmm.TagCheck (checkConArgsStatic, checkConArgsDyn, emitTagAssertion, emitTagAssertionId)
 import GHC.Utils.Outputable
 import GHC.Utils.Trace
+import Data.Maybe
 
 ---------------------------------------------------------------
 --      Top-level constructors
@@ -82,12 +81,10 @@ cgTopRhsCon cfg id con mn args
     -- See Note [About the NameSorts] in "GHC.Types.Name" for Internal/External
     (static_info, static_code)
 
-  -- Virtual constructor, just return the argument, behaves more like an closure
-  | virtualDataConType con /= NonVirtual
+  -- Virtual constructor, just return the argument.
+  | virtualDataConType con == VirtualBoxed
   , [NonVoid (StgVarArg x)] <- args
-  -- It could only be unboxed if we implemented top level unlifted boxy data types.
-  = assert (virtualDataConType con == VirtualBoxed) $
-    let fake_rhs = StgConApp con {-unused-}NoNumber [StgVarArg x] [idType x] :: CgStgExpr
+  = panic "topRhsCon" $ let fake_rhs = StgApp x []
     in
       pprTrace "cgTopRhsCon" (ppr id $$ ppr con $$ ppr args) $
       cgTopRhsClosure platform NonRecursive id dontCareCCS Updatable [] fake_rhs
@@ -207,32 +204,22 @@ the addr modes of the args is that we may be in a "knot", and
 premature looking at the args will cause the compiler to black-hole!
 -}
 -------- buildDynCon': Virtual constructor -----------
-buildDynCon' binder _mn _actually_bound _ccs con args
-  | vcon <- virtualDataConType con
-  , vcon /= NonVirtual
+buildDynCon' binder mn actually_bound ccs con args
+  | virtualDataConType con == VirtualBoxed
   , [NonVoid (StgVarArg arg)] <- assert (length args == 1) args
   = do
-      pprTraceM "buildDynCon" (ppr con)
       cfg <- getStgToCmmConfig
       let platform = stgToCmmPlatform cfg
 
       m_arg_cg_info <- (getCgInfo_maybe $ idName arg)
       case m_arg_cg_info of
-        Just arg_info@CgIdInfo{ cg_loc, cg_id } -> do
-          case vcon of
-            -- A virtual con for regular boxed things is just the argument info under another name.
-            VirtualBoxed -> do
-              emitTagAssertionId "buildDynConVirt:" arg
-              let virt_con_info = arg_info { cg_id = binder }
-              return (virt_con_info, return mempty)
-            -- These things usually don't have a pointer tag. But here we attach one to avoid these values from being entered.
-            VirtualUnboxedHeap
-              | CmmLoc{ cgl_cmm } <- cg_loc -> do
-                  let virt_con_info = arg_info { cg_id = binder, cg_loc = cg_loc { cgl_cmm = cmmOffset platform cgl_cmm 1 } }
-                  return (virt_con_info, return mempty)
-              | otherwise -> panic "VirtualCon with LNE value as argument"
-            NonVirtual -> panic "impossible" -- handled by guard on buildDynCon'/CmmLoc
+        Just arg_info -> do
+          emitTagAssertionId "buildDynConVirt:" arg
+
+          -- A virtual con is just the arguments info under another name.
+          let fake_con_info = arg_info { cg_id = binder }
 
+          return (fake_con_info, return mempty)
         Nothing -> panic "buildDynCon': LFInfo for VCon args unknown" (ppr binder <> text " = " <> ppr con <+> ppr args)
 
           -- let !lf_info = mkLFArgument arg
@@ -435,16 +422,9 @@ bindConArgs :: AltCon -> LocalReg -> [NonVoid Id] -> FCode [LocalReg]
 bindConArgs (DataAlt con) base args
   | isVirtualDataCon con
   , [NonVoid arg] <- assert (length args == 1) args
-  = case virtualDataConType con of
-      NonVirtual -> panic "Impossible" -- checked by guard above
-      VirtualBoxed -> do
-        bindArgToGivenReg (NonVoid arg) base
-        return [base]
-      VirtualUnboxedHeap -> do
-        pprTraceM "BindOffset" (ppr con)
-        bindArgToGivenRegOffset (NonVoid arg) base (-1)
-        return [base]
-
+  = do
+      bindArgToGivenReg (NonVoid arg) base
+      return [base]
 
   | otherwise = assert (not (isUnboxedTupleDataCon con)) $
     do profile <- getProfile
diff --git a/compiler/GHC/StgToCmm/Env.hs b/compiler/GHC/StgToCmm/Env.hs
index 2d9c83ba0e..824d47d398 100644
--- a/compiler/GHC/StgToCmm/Env.hs
+++ b/compiler/GHC/StgToCmm/Env.hs
@@ -18,7 +18,7 @@ module GHC.StgToCmm.Env (
         bindArgsToRegs, bindToReg, rebindToReg,
         bindArgToReg, bindArgToGivenReg, idToReg,
         getCgIdInfo, getCgInfo_maybe,
-        maybeLetNoEscape, bindArgToGivenRegOffset,
+        maybeLetNoEscape,
         ) where
 
 import GHC.Prelude
@@ -191,11 +191,6 @@ bindArgToGivenReg (NonVoid id) reg
   = do let !lf_info = mkLFArgument id
        addBindC (mkCgIdInfo id lf_info (CmmReg (CmmLocal reg)))
 
-bindArgToGivenRegOffset :: NonVoid Id -> LocalReg -> Int -> FCode ()
--- Records that an arg is already present in the given reg
-bindArgToGivenRegOffset (NonVoid id) reg offset
-  = do let !lf_info = mkLFArgument id
-       addBindC (mkCgIdInfo id lf_info (CmmRegOff (CmmLocal reg) offset))
 
 rebindToReg :: NonVoid Id -> FCode LocalReg
 -- Like bindToReg, but the Id is already in scope, so
diff --git a/compiler/GHC/StgToCmm/Expr.hs b/compiler/GHC/StgToCmm/Expr.hs
index 0a77859210..e0b5a9dfa2 100644
--- a/compiler/GHC/StgToCmm/Expr.hs
+++ b/compiler/GHC/StgToCmm/Expr.hs
@@ -37,7 +37,7 @@ import GHC.Cmm.Graph
 import GHC.Cmm.BlockId
 import GHC.Cmm hiding ( succ )
 import GHC.Cmm.Info
-import GHC.Cmm.Utils ( zeroExpr, cmmTagMask, mkWordCLit, mAX_PTR_TAG, cmmOffset )
+import GHC.Cmm.Utils ( zeroExpr, cmmTagMask, mkWordCLit, mAX_PTR_TAG )
 import GHC.Core
 import GHC.Core.DataCon
 import GHC.Types.ForeignCall
@@ -45,7 +45,7 @@ import GHC.Types.Id
 import GHC.Builtin.PrimOps
 import GHC.Core.TyCon
 import GHC.Core.Type        ( isUnliftedType )
-import GHC.Types.RepType    ( isZeroBitTy, countConRepArgs, mightBeFunTy )
+import GHC.Types.RepType    ( isZeroBitTy, countConRepArgs, mightBeFunTy, isVirtualTyCon )
 import GHC.Types.CostCentre ( CostCentreStack, currentCCS )
 import GHC.Types.Tickish
 import GHC.Data.Maybe
@@ -60,7 +60,6 @@ import Control.Arrow ( first )
 import Data.List     ( partition )
 import GHC.Stg.InferTags.TagSig (isTaggedSig)
 import GHC.Platform.Profile (profileIsProfiling)
-import GHC.Types.Rep.Virtual
 
 ------------------------------------------------------------------------
 --              cgExpr: the main function
@@ -131,11 +130,16 @@ cgExpr (StgOpApp op args ty) = cgOpApp op args ty
 cgExpr (StgConApp con mn args _)
   -- Unlike for a regular con for a virtual con we
   -- might have to evaluate the argument here!
-  -- | isVirtualDataCon con
-  -- , arg <- getArg args
-  -- = cgExpr (StgApp arg [])
+  | isVirtualTyCon (dataConTyCon con)
+  , arg <- getArg args
+  = cgExpr (StgApp arg [])
   | otherwise
   = cgConApp con mn args
+  where
+      getArg args
+        | [StgVarArg arg] <- args
+        = arg
+        | otherwise = pprPanic "Very odd virtalCon" (ppr con <> ppr args)
 cgExpr (StgTick t e)         = cgTick t >> cgExpr e
 cgExpr (StgLit lit)          = do cmm_expr <- cgLit lit
                                   emitReturn [cmm_expr]
@@ -985,16 +989,11 @@ cgConApp con mn stg_args
        ; emitReturn arg_exprs }
 
   -- Virtual constructor, just return the argument.
-  | isVirtualDataCon con
+  | isVirtualTyCon (dataConTyCon con)
   , [StgVarArg arg] <- assert (length stg_args == 1) stg_args
   = do
       info <- getCgIdInfo arg
-      platform <- getPlatform
-      let !arg_cmm = idInfoToAmode info
-      if virtualDataConType con == VirtualBoxed
-        then emitReturn [arg_cmm]
-        -- "Unboxed" heap object without a tag, make one up.
-        else emitReturn [cmmOffset platform arg_cmm 1]
+      emitReturn [idInfoToAmode info]
 
   | otherwise   --  Boxed constructors; allocate and return
   = assertPpr (stg_args `lengthIs` countConRepArgs con)
diff --git a/compiler/GHC/Types/CostCentre.hs b/compiler/GHC/Types/CostCentre.hs
index 1d5cec6c94..092b727d8d 100644
--- a/compiler/GHC/Types/CostCentre.hs
+++ b/compiler/GHC/Types/CostCentre.hs
@@ -189,7 +189,7 @@ data CostCentreStack
 
   | SingletonCCS CostCentre
 
-  deriving (Eq, Ord, Data)    -- needed for Ord on CLabel
+  deriving (Eq, Ord)    -- needed for Ord on CLabel
 
 
 -- synonym for triple which describes the cost centre info in the generated
diff --git a/compiler/GHC/Types/Id/Info.hs b/compiler/GHC/Types/Id/Info.hs
index 743eb7bf86..edd1ba0da0 100644
--- a/compiler/GHC/Types/Id/Info.hs
+++ b/compiler/GHC/Types/Id/Info.hs
@@ -13,7 +13,6 @@ Haskell. [WDP 94/11])
 {-# LANGUAGE BinaryLiterals #-}
 
 {-# OPTIONS_GHC -Wno-incomplete-record-updates #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Types.Id.Info (
         -- * The IdDetails type
@@ -110,7 +109,6 @@ import GHC.Stg.InferTags.TagSig
 import Data.Word
 
 import GHC.StgToCmm.Types (LambdaFormInfo)
-import Data.Data (Data)
 
 -- infixl so you can say (id `set` a `set` b)
 infixl  1 `setRuleInfo`,
@@ -721,7 +719,7 @@ data CafInfo
 
         | NoCafRefs                     -- ^ A function or static constructor
                                         -- that refers to no CAFs.
-        deriving (Eq, Ord, Data)
+        deriving (Eq, Ord)
 
 -- | Assumes that the 'Id' has CAF references: definitely safe
 vanillaCafInfo :: CafInfo
diff --git a/compiler/GHC/Types/Rep/Virtual.hs b/compiler/GHC/Types/Rep/Virtual.hs
deleted file mode 100644
index d86c8444de..0000000000
--- a/compiler/GHC/Types/Rep/Virtual.hs
+++ /dev/null
@@ -1,120 +0,0 @@
-
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE InstanceSigs #-}
-
-module GHC.Types.Rep.Virtual
-  (
-    isVirtualTyCon, isVirtualDataCon, virtualDataConType, VirtualConType(..)
-  ) where
-
-import GHC.Prelude
-
-import GHC.Types.RepType
-import GHC.Core.DataCon
-import GHC.Core.TyCon
-import GHC.Core.TyCo.Rep
-import GHC.Core.Type
-
-import GHC.Utils.Misc
-import GHC.Utils.Outputable
-
-import GHC.Utils.Trace
-import GHC.Builtin.Types.Prim
-
-{- **********************************************************************
-*                                                                       *
-                Virtual Data Con stuff
-*                                                                       *
-********************************************************************** -}
-
-data VirtualConType = VirtualBoxed -- ^ These have a regular pointer tag
-                    | VirtualUnboxedHeap -- ^ ByteArray# and friends. These don't usually have pointers.
-                    | NonVirtual -- ^ Can't be shorted out.
-                    deriving (Eq,Show)
-
-instance Outputable VirtualConType where
-  ppr :: VirtualConType -> SDoc
-  ppr = text . show
-
-isVirtualDataCon :: DataCon -> Bool
-isVirtualDataCon con = virtualDataConType con /= NonVirtual
-
-virtualDataConType :: DataCon -> VirtualConType
-virtualDataConType = isVirtualTyCon . dataConTyCon
-
--- Is this unlifted type a fixed unboxed heap object type
-isUnboxedVirtualTyCon :: TyCon -> Bool
-isUnboxedVirtualTyCon tc
-  | tc `elem`
-    -- These are heap objects who naturally have pointer tag zero.
-    [ arrayPrimTyCon
-    , byteArrayPrimTyCon
-    , smallArrayPrimTyCon
-    , mutableArrayPrimTyCon
-    , mutableByteArrayPrimTyCon
-    , smallMutableArrayPrimTyCon
-    , mVarPrimTyCon
-    , ioPortPrimTyCon
-    , tVarPrimTyCon
-    , mutVarPrimTyCon
-
-    -- For these below I'm not sure about
-    -- their representation.
-    -- , weakPrimTyCon
-    -- , stablePtrPrimTyCon
-    -- , stableNamePrimTyCon
-    -- , compactPrimTyCon
-    -- , stackSnapshotPrimTyCon
-    -- , promptTagPrimTyCon
-
-    -- , tYPETyCon
-    -- , funTyCon
-    ]
-  = True
-  | otherwise = False
-
-isVirtualTyCon :: HasDebugCallStack => TyCon -> VirtualConType
-isVirtualTyCon tc
-  -- Exactly one constructor
-  | [dc] <- tyConDataCons tc
-  -- No (runtime) constraints
-  , [] <- filter (not . isZeroBitTy) (dataConOtherTheta dc)
-  -- , pprTrace "isV.2" (ppr dc <> text ":" <> ppr tc) True
-  --Exactly one non-void field argument
-  , rep_bangs <- dataConRepStrictness dc
-  , rep_tys <- dataConRepArgTys dc
-  , all (tyHasFixedRuntimeRep) $ map scaledThing rep_tys
-  -- , pprTrace "args,bangs" (ppr rep_bangs <> ppr rep_tys) True
-  , [(field :: Type, strictness)] <- filter (not . isZeroBitTy . fst) $
-                             zipWithEqual "isVirtualTyCon" (\a b -> (scaledThing a, b))
-                             (rep_tys) (rep_bangs)
-  , pprTrace "isV.3" empty True
-  -- That field is boxed
-  , isBoxedType field
-  , pprTrace "isV.4" empty True
-  -- And it's a boxed ADT!
-  , isBoxedType (dataConOrigResTy dc)
-  -- The field is either unlifted boxed or strict
-  = if (isUnliftedType field)
-      then
-        isSafeUnlifted field
-      else
-        isSafeLifted strictness
-  -- , pprTrace "isV.7" empty True
-  -- -- Result is boxed
-  -- = pprTrace "foundVirtualCon:" (ppr dc <> text ":" <> ppr tc <> text "@" <> ppr field) True
-  | otherwise = NonVirtual
-  where
-    isSafeLifted strictness = case strictness of MarkedStrict -> pprTrace "safeBoxed" (ppr tc)  VirtualBoxed; _ -> NonVirtual
-
-    isSafeUnlifted field
-      | Just field_tc <- tyConAppTyCon_maybe field
-      -- , pprTrace "ftc" (ppr field_tc) True
-      , isDataTyCon field_tc
-      = pprTrace "safeBoxedU" (ppr tc) VirtualBoxed
-      | Just field_tc <- tyConAppTyCon_maybe field
-      , isUnboxedVirtualTyCon field_tc
-      = pprTrace "safeUnboxed" (ppr tc) VirtualUnboxedHeap
-      -- = NonVirtual
-      -- TODO: Hashmaps etc.
-      | otherwise = NonVirtual
diff --git a/compiler/GHC/Types/RepType.hs b/compiler/GHC/Types/RepType.hs
index 4d4a797380..c5c92fefb9 100644
--- a/compiler/GHC/Types/RepType.hs
+++ b/compiler/GHC/Types/RepType.hs
@@ -23,11 +23,10 @@ module GHC.Types.RepType
     ubxSumRepType, layoutUbxSum, typeSlotTy, SlotTy (..),
     slotPrimRep, primRepSlot,
 
-    tyHasFixedRuntimeRep,
-
     -- * Is this type known to be data?
     mightBeFunTy,
 
+    isVirtualTyCon, isVirtualDataCon, virtualDataConType, VirtualConType(..)
     ) where
 
 import GHC.Prelude
@@ -62,6 +61,7 @@ import GHC.Utils.Panic
 import GHC.Utils.Panic.Plain
 
 import Data.List (sort)
+import GHC.Utils.Trace
 import qualified Data.IntSet as IS
 
 {- **********************************************************************
@@ -700,3 +700,65 @@ mightBeFunTy ty
   | otherwise
   = True
 
+------------------------------------------
+--   Virtual Data Con stuff
+------------------------------------------
+
+data VirtualConType = VirtualBoxed -- ^ These have a regular pointer tag
+                    | VirtualUnboxed -- ^ ByteArray# and friends. These don't usually have pointers.
+                    | NonVirtual -- ^ Can't be shorted out.
+                    deriving (Eq,Show)
+
+instance Outputable VirtualConType where
+  ppr :: VirtualConType -> SDoc
+  ppr = text . show
+
+isVirtualDataCon :: DataCon -> Bool
+isVirtualDataCon con = virtualDataConType con /= NonVirtual
+
+virtualDataConType :: DataCon -> VirtualConType
+virtualDataConType = isVirtualTyCon . dataConTyCon
+
+isVirtualTyCon :: HasDebugCallStack => TyCon -> VirtualConType
+isVirtualTyCon tc
+  -- Exactly one constructor
+  | [dc] <- tyConDataCons tc
+  -- No (runtime) constraints
+  , [] <- filter (not . isZeroBitTy) (dataConOtherTheta dc)
+  -- , pprTrace "isV.2" (ppr dc <> text ":" <> ppr tc) True
+  --Exactly one non-void field argument
+  , rep_bangs <- dataConRepStrictness dc
+  , rep_tys <- dataConRepArgTys dc
+  , all (tyHasFixedRuntimeRep) $ map scaledThing rep_tys
+  -- , pprTrace "args,bangs" (ppr rep_bangs <> ppr rep_tys) True
+  , [(field :: Type, strictness)] <- filter (not . isZeroBitTy . fst) $
+                             zipWithEqual "isVirtualTyCon" (\a b -> (scaledThing a, b))
+                             (rep_tys) (rep_bangs)
+  , pprTrace "isV.3" empty True
+  -- That field is boxed
+  , isBoxedType field
+  , pprTrace "isV.4" empty True
+  -- And it's a boxed ADT!
+  -- , pprTrace "isV.5" empty True
+  -- , pprTrace "isV.6" empty True
+  -- That field is either unlifted or strict
+  , isBoxedType (dataConOrigResTy dc)
+  = if (isUnliftedType field)
+      then
+        (\r -> pprTrace "safeUnlifted " (ppr tc <+> ppr r) r) (isSafeUnlifted field)
+      else
+        isSafeLifted strictness
+  -- , pprTrace "isV.7" empty True
+  -- -- Result is boxed
+  -- = pprTrace "foundVirtualCon:" (ppr dc <> text ":" <> ppr tc <> text "@" <> ppr field) True
+  | otherwise = NonVirtual
+  where
+    isSafeLifted strictness = case strictness of MarkedStrict -> VirtualBoxed; _ -> NonVirtual
+
+    isSafeUnlifted field
+      | Just field_tc <- tyConAppTyCon_maybe field
+      -- , pprTrace "ftc" (ppr field_tc) True
+      , isDataTyCon field_tc
+      = VirtualBoxed
+      -- TODO: Hashmaps etc.
+      | otherwise = NonVirtual
diff --git a/compiler/GHC/Types/Unique.hs b/compiler/GHC/Types/Unique.hs
index e86139c9d5..60d1c452e2 100644
--- a/compiler/GHC/Types/Unique.hs
+++ b/compiler/GHC/Types/Unique.hs
@@ -19,7 +19,6 @@ Haskell).
 
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE BangPatterns, MagicHash #-}
-{-# LANGUAGE DeriveDataTypeable #-}
 
 module GHC.Types.Unique (
         -- * Main data types
@@ -61,7 +60,6 @@ import GHC.Exts (indexCharOffAddr#, Char(..), Int(..))
 import Data.Char        ( chr, ord )
 
 import Language.Haskell.Syntax.Module.Name
-import Data.Data (Data)
 
 {-
 ************************************************************************
@@ -93,7 +91,7 @@ GHC.Builtin.Uniques. See Note [Uniques for wired-in prelude things and known mas
 -- the functions from the 'UniqSupply' module
 --
 -- These are sometimes also referred to as \"keys\" in comments in GHC.
-newtype Unique = MkUnique Int deriving Data
+newtype Unique = MkUnique Int
 
 {-# INLINE uNIQUE_BITS #-}
 uNIQUE_BITS :: Int
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index 5a2e93ec91..0ac1080c65 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -732,7 +732,6 @@ Library
         GHC.Types.PkgQual
         GHC.Types.ProfAuto
         GHC.Types.RepType
-        GHC.Types.Rep.Virtual
         GHC.Types.SafeHaskell
         GHC.Types.SourceError
         GHC.Types.SourceFile