Cmm: DynFlags to CmmConfig refactor

add files GHC.Cmm.Config, GHC.Driver.Config.Cmm

Cmm: DynFlag references --> CmmConfig

Cmm.Pipeline: reorder imports, add handshake

Cmm: DynFlag references --> CmmConfig

Cmm.Pipeline: DynFlag references --> CmmConfig

Cmm.LayoutStack: DynFlag references -> CmmConfig

Cmm.Info.Build: DynFlag references -> CmmConfig

Cmm.Config: use profile to retrieve platform

Cmm.CLabel: unpack NCGConfig in labelDynamic

Cmm.Config: reduce CmmConfig surface area

Cmm.Config: add cmmDoCmmSwitchPlans field

Cmm.Config: correct cmmDoCmmSwitchPlans flag

The original implementation dispatches work in cmmImplementSwitchPlans
in an `otherwise` branch, hence we must add a not to correctly dispatch

Cmm.Config: add cmmSplitProcPoints simplify Config

remove cmmBackend, and cmmPosInd

Cmm.CmmToAsm: move ncgLabelDynamic to CmmToAsm

Cmm.CLabel: remove cmmLabelDynamic function

Cmm.Config: rename cmmOptDoLinting -> cmmDoLinting

testsuite: update CountDepsAst CountDepsParser

11 files changed, 175 insertions, 114 deletions

diff --git a/compiler/GHC/Cmm/CLabel.hs b/compiler/GHC/Cmm/CLabel.hs
index fad545f662..de608bafd4 100644
--- a/compiler/GHC/Cmm/CLabel.hs
+++ b/compiler/GHC/Cmm/CLabel.hs
@@ -152,7 +152,6 @@ import GHC.Platform
 import GHC.Types.Unique.Set
 import GHC.Utils.Misc
 import GHC.Core.Ppr ( {- instances -} )
-import GHC.CmmToAsm.Config
 import GHC.Types.SrcLoc
 
 -- -----------------------------------------------------------------------------
@@ -1177,21 +1176,21 @@ isLocalCLabel this_mod lbl =
 -- that data resides in a DLL or not. [Win32 only.]
 -- @labelDynamic@ returns @True@ if the label is located
 -- in a DLL, be it a data reference or not.
-labelDynamic :: NCGConfig -> CLabel -> Bool
-labelDynamic config lbl =
+labelDynamic :: Module -> Platform -> Bool -> CLabel -> Bool
+labelDynamic this_mod platform external_dynamic_refs lbl =
   case lbl of
    -- is the RTS in a DLL or not?
    RtsLabel _ ->
-     externalDynamicRefs && (this_unit /= rtsUnitId)
+     external_dynamic_refs && (this_unit /= rtsUnitId)
 
    IdLabel n _ _ ->
-     externalDynamicRefs && isDynLinkName platform this_mod n
+     external_dynamic_refs && isDynLinkName platform this_mod n
 
    -- When compiling in the "dyn" way, each package is to be linked into
    -- its own shared library.
    CmmLabel lbl_unit _ _ _
-    | os == OSMinGW32 -> externalDynamicRefs && (this_unit /= lbl_unit)
-    | otherwise       -> externalDynamicRefs
+    | os == OSMinGW32 -> external_dynamic_refs && (this_unit /= lbl_unit)
+    | otherwise       -> external_dynamic_refs
 
    LocalBlockLabel _    -> False
 
@@ -1209,7 +1208,7 @@ labelDynamic config lbl =
             -- When compiling in the "dyn" way, each package is to be
             -- linked into its own DLL.
             ForeignLabelInPackage pkgId ->
-                externalDynamicRefs && (this_unit /= pkgId)
+                external_dynamic_refs && (this_unit /= pkgId)
 
        else -- On Mac OS X and on ELF platforms, false positives are OK,
             -- so we claim that all foreign imports come from dynamic
@@ -1217,25 +1216,21 @@ labelDynamic config lbl =
             True
 
    CC_Label cc ->
-     externalDynamicRefs && not (ccFromThisModule cc this_mod)
+     external_dynamic_refs && not (ccFromThisModule cc this_mod)
 
    -- CCS_Label always contains a CostCentre defined in the current module
    CCS_Label _ -> False
    IPE_Label {} -> True
 
    HpcTicksLabel m ->
-     externalDynamicRefs && this_mod /= m
+     external_dynamic_refs && this_mod /= m
 
    -- Note that DynamicLinkerLabels do NOT require dynamic linking themselves.
    _                 -> False
   where
-    externalDynamicRefs = ncgExternalDynamicRefs config
-    platform = ncgPlatform config
-    os = platformOS platform
-    this_mod = ncgThisModule config
+    os        = platformOS platform
     this_unit = toUnitId (moduleUnit this_mod)
 
-
 -----------------------------------------------------------------------------
 -- Printing out CLabels.
 
diff --git a/compiler/GHC/Cmm/Config.hs b/compiler/GHC/Cmm/Config.hs
new file mode 100644
index 0000000000..12eb4e47dc
--- /dev/null
+++ b/compiler/GHC/Cmm/Config.hs
@@ -0,0 +1,32 @@
+-- | Cmm compilation configuration
+
+{-# LANGUAGE DerivingStrategies         #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+module GHC.Cmm.Config
+  ( CmmConfig(..)
+  , cmmPlatform
+  ) where
+
+import GHC.Prelude
+
+import GHC.Platform
+import GHC.Platform.Profile
+
+
+data CmmConfig = CmmConfig
+  { cmmProfile             :: !Profile -- ^ Target Profile
+  , cmmOptControlFlow      :: !Bool    -- ^ Optimize Cmm Control Flow or not
+  , cmmDoLinting           :: !Bool    -- ^ Do Cmm Linting Optimization or not
+  , cmmOptElimCommonBlks   :: !Bool    -- ^ Eliminate common blocks or not
+  , cmmOptSink             :: !Bool    -- ^ Perform sink after stack layout or not
+  , cmmGenStackUnwindInstr :: !Bool    -- ^ Generate stack unwinding instructions (for debugging)
+  , cmmExternalDynamicRefs :: !Bool    -- ^ Generate code to link against dynamic libraries
+  , cmmDoCmmSwitchPlans    :: !Bool    -- ^ Should the Cmm pass replace Stg switch statements
+  , cmmSplitProcPoints     :: !Bool    -- ^ Should Cmm split proc points or not
+  }
+
+-- | retrieve the target Cmm platform
+cmmPlatform :: CmmConfig -> Platform
+cmmPlatform = profilePlatform . cmmProfile
+
diff --git a/compiler/GHC/Cmm/Info/Build.hs b/compiler/GHC/Cmm/Info/Build.hs
index 191415274e..01f3c2a3ff 100644
--- a/compiler/GHC/Cmm/Info/Build.hs
+++ b/compiler/GHC/Cmm/Info/Build.hs
@@ -23,6 +23,7 @@ import GHC.Platform.Profile
 import GHC.Types.Id
 import GHC.Types.Id.Info
 import GHC.Cmm.BlockId
+import GHC.Cmm.Config
 import GHC.Cmm.Dataflow.Block
 import GHC.Cmm.Dataflow.Graph
 import GHC.Cmm.Dataflow.Label
@@ -33,7 +34,6 @@ import GHC.Data.Graph.Directed
 import GHC.Cmm.CLabel
 import GHC.Cmm
 import GHC.Cmm.Utils
-import GHC.Driver.Session
 import GHC.Data.Maybe
 import GHC.Utils.Outputable
 import GHC.Utils.Panic
@@ -41,7 +41,6 @@ import GHC.Runtime.Heap.Layout
 import GHC.Types.Unique.Supply
 import GHC.Types.CostCentre
 import GHC.StgToCmm.Heap
-import GHC.Driver.Config.CmmToAsm
 
 import Control.Monad
 import Data.Map.Strict (Map)
@@ -793,16 +792,16 @@ resolveCAF platform srtMap lbl@(CAFLabel l) =
 -- declarations to the ModuleSRTInfo.
 --
 doSRTs
-  :: DynFlags
+  :: CmmConfig
   -> ModuleSRTInfo
   -> [(CAFEnv, [CmmDecl])]
   -> [(CAFSet, CmmDecl)]
   -> IO (ModuleSRTInfo, [CmmDeclSRTs])
 
-doSRTs dflags moduleSRTInfo procs data_ = do
+doSRTs cfg moduleSRTInfo procs data_ = do
   us <- mkSplitUniqSupply 'u'
 
-  let profile = targetProfile dflags
+  let profile = cmmProfile cfg
 
   -- Ignore the original grouping of decls, and combine all the
   -- CAFEnvs into a single CAFEnv.
@@ -827,7 +826,7 @@ doSRTs dflags moduleSRTInfo procs data_ = do
       decls = map snd data_ ++ concat procss
       staticFuns = mapFromList (getStaticFuns decls)
 
-      platform = targetPlatform dflags
+      platform = cmmPlatform cfg
 
   -- Put the decls in dependency order. Why? So that we can implement
   -- [Inline] and [Filter].  If we need to refer to an SRT that has
@@ -860,9 +859,9 @@ doSRTs dflags moduleSRTInfo procs data_ = do
       (result, moduleSRTInfo') =
         initUs_ us $
         flip runStateT moduleSRTInfo $ do
-          nonCAFs <- mapM (doSCC dflags staticFuns static_data) sccs
+          nonCAFs <- mapM (doSCC cfg staticFuns static_data) sccs
           cAFs <- forM cafsWithSRTs $ \(l, cafLbl, cafs) ->
-            oneSRT dflags staticFuns [BlockLabel l] [cafLbl]
+            oneSRT cfg staticFuns [BlockLabel l] [cafLbl]
                    True{-is a CAF-} cafs static_data
           return (nonCAFs ++ cAFs)
 
@@ -904,7 +903,7 @@ doSRTs dflags moduleSRTInfo procs data_ = do
 
 -- | Build the SRT for a strongly-connected component of blocks
 doSCC
-  :: DynFlags
+  :: CmmConfig
   -> LabelMap CLabel -- which blocks are static function entry points
   -> Set CLabel -- static data
   -> SCC (SomeLabel, CAFLabel, Set CAFLabel)
@@ -915,14 +914,14 @@ doSCC
         , Bool                   -- Whether the group has CAF references
         )
 
-doSCC dflags staticFuns static_data (AcyclicSCC (l, cafLbl, cafs)) =
-  oneSRT dflags staticFuns [l] [cafLbl] False cafs static_data
+doSCC cfg staticFuns static_data (AcyclicSCC (l, cafLbl, cafs)) =
+  oneSRT cfg staticFuns [l] [cafLbl] False cafs static_data
 
-doSCC dflags staticFuns static_data (CyclicSCC nodes) = do
+doSCC cfg staticFuns static_data (CyclicSCC nodes) = do
   -- build a single SRT for the whole cycle, see Note [recursive SRTs]
   let (lbls, caf_lbls, cafsets) = unzip3 nodes
       cafs = Set.unions cafsets
-  oneSRT dflags staticFuns lbls caf_lbls False cafs static_data
+  oneSRT cfg staticFuns lbls caf_lbls False cafs static_data
 
 
 {- Note [recursive SRTs]
@@ -951,7 +950,7 @@ references to static function closures.
 
 -- | Build an SRT for a set of blocks
 oneSRT
-  :: DynFlags
+  :: CmmConfig
   -> LabelMap CLabel            -- which blocks are static function entry points
   -> [SomeLabel]                -- blocks in this set
   -> [CAFLabel]                 -- labels for those blocks
@@ -965,15 +964,14 @@ oneSRT
        , Bool                         -- Whether the group has CAF references
        )
 
-oneSRT dflags staticFuns lbls caf_lbls isCAF cafs static_data = do
+oneSRT cfg staticFuns lbls caf_lbls isCAF cafs static_data = do
   topSRT <- get
 
   let
     this_mod = thisModule topSRT
-    config = initNCGConfig dflags this_mod
-    profile = targetProfile dflags
+    profile  = cmmProfile cfg
     platform = profilePlatform profile
-    srtMap = moduleSRTMap topSRT
+    srtMap   = moduleSRTMap topSRT
 
     blockids = getBlockLabels lbls
 
@@ -1070,7 +1068,7 @@ oneSRT dflags staticFuns lbls caf_lbls isCAF cafs static_data = do
           -- when dynamic linking is used we cannot guarantee that the offset
           -- between the SRT and the info table will fit in the offset field.
           -- Consequently we build a singleton SRT in this case.
-          not (labelDynamic config lbl)
+          not (labelDynamic this_mod platform (cmmExternalDynamicRefs cfg) lbl)
 
           -- MachO relocations can't express offsets between compilation units at
           -- all, so we are always forced to build a singleton SRT in this case.
diff --git a/compiler/GHC/Cmm/LayoutStack.hs b/compiler/GHC/Cmm/LayoutStack.hs
index b996427bba..ad13e8f431 100644
--- a/compiler/GHC/Cmm/LayoutStack.hs
+++ b/compiler/GHC/Cmm/LayoutStack.hs
@@ -15,6 +15,7 @@ import GHC.StgToCmm.Foreign    ( saveThreadState, loadThreadState ) -- XXX layer
 import GHC.Cmm
 import GHC.Cmm.Info
 import GHC.Cmm.BlockId
+import GHC.Cmm.Config
 import GHC.Cmm.Utils
 import GHC.Cmm.Graph
 import GHC.Cmm.Liveness
@@ -30,7 +31,6 @@ import GHC.Data.Maybe
 import GHC.Types.Unique.FM
 import GHC.Utils.Misc
 
-import GHC.Driver.Session
 import GHC.Utils.Outputable hiding ( isEmpty )
 import GHC.Utils.Panic
 import qualified Data.Set as Set
@@ -235,21 +235,21 @@ instance Outputable StackMap where
      text "sm_regs = " <> pprUFM sm_regs ppr
 
 
-cmmLayoutStack :: DynFlags -> ProcPointSet -> ByteOff -> CmmGraph
+cmmLayoutStack :: CmmConfig -> ProcPointSet -> ByteOff -> CmmGraph
                -> UniqSM (CmmGraph, LabelMap StackMap)
-cmmLayoutStack dflags procpoints entry_args
+cmmLayoutStack cfg procpoints entry_args
                graph@(CmmGraph { g_entry = entry })
   = do
     -- We need liveness info. Dead assignments are removed later
     -- by the sinking pass.
     let liveness = cmmLocalLiveness platform graph
-        blocks = revPostorder graph
-        profile  = targetProfile dflags
+        blocks   = revPostorder graph
+        profile  = cmmProfile   cfg
         platform = profilePlatform profile
 
     (final_stackmaps, _final_high_sp, new_blocks) <-
           mfix $ \ ~(rec_stackmaps, rec_high_sp, _new_blocks) ->
-            layout dflags procpoints liveness entry entry_args
+            layout cfg procpoints liveness entry entry_args
                    rec_stackmaps rec_high_sp blocks
 
     blocks_with_reloads <-
@@ -261,7 +261,7 @@ cmmLayoutStack dflags procpoints entry_args
 -- Pass 1
 -- -----------------------------------------------------------------------------
 
-layout :: DynFlags
+layout :: CmmConfig
        -> LabelSet                      -- proc points
        -> LabelMap CmmLocalLive         -- liveness
        -> BlockId                       -- entry
@@ -278,7 +278,7 @@ layout :: DynFlags
           , [CmmBlock]                  -- [out] new blocks
           )
 
-layout dflags procpoints liveness entry entry_args final_stackmaps final_sp_high blocks
+layout cfg procpoints liveness entry entry_args final_stackmaps final_sp_high blocks
   = go blocks init_stackmap entry_args []
   where
     (updfr, cont_info)  = collectContInfo blocks
@@ -311,7 +311,7 @@ layout dflags procpoints liveness entry entry_args final_stackmaps final_sp_high
        --     each of the successor blocks.  See handleLastNode for
        --     details.
        (middle1, sp_off, last1, fixup_blocks, out)
-           <- handleLastNode dflags procpoints liveness cont_info
+           <- handleLastNode cfg procpoints liveness cont_info
                              acc_stackmaps stack1 tscope middle0 last0
 
        -- (c) Manifest Sp: run over the nodes in the block and replace
@@ -326,7 +326,7 @@ layout dflags procpoints liveness entry entry_args final_stackmaps final_sp_high
        let middle_pre = blockToList $ foldl' blockSnoc middle0 middle1
 
        let final_blocks =
-               manifestSp dflags final_stackmaps stack0 sp0 final_sp_high
+               manifestSp cfg final_stackmaps stack0 sp0 final_sp_high
                           entry0 middle_pre sp_off last1 fixup_blocks
 
        let acc_stackmaps' = mapUnion acc_stackmaps out
@@ -433,7 +433,7 @@ getStackLoc (Young l) n stackmaps =
 -- extra code that goes *after* the Sp adjustment.
 
 handleLastNode
-   :: DynFlags -> ProcPointSet -> LabelMap CmmLocalLive -> LabelMap ByteOff
+   :: CmmConfig -> ProcPointSet -> LabelMap CmmLocalLive -> LabelMap ByteOff
    -> LabelMap StackMap -> StackMap -> CmmTickScope
    -> Block CmmNode O O
    -> CmmNode O C
@@ -445,7 +445,7 @@ handleLastNode
       , LabelMap StackMap  -- stackmaps for the continuations
       )
 
-handleLastNode dflags procpoints liveness cont_info stackmaps
+handleLastNode cfg procpoints liveness cont_info stackmaps
                stack0@StackMap { sm_sp = sp0 } tscp middle last
   = case last of
       --  At each return / tail call,
@@ -467,7 +467,7 @@ handleLastNode dflags procpoints liveness cont_info stackmaps
       CmmCondBranch {} ->  handleBranches
       CmmSwitch {}     ->  handleBranches
   where
-     platform = targetPlatform dflags
+     platform = cmmPlatform cfg
      -- Calls and ForeignCalls are handled the same way:
      lastCall :: BlockId -> ByteOff -> ByteOff -> ByteOff
               -> ( [CmmNode O O]
@@ -544,7 +544,7 @@ handleLastNode dflags procpoints liveness cont_info stackmaps
         | Just stack2 <- mapLookup l stackmaps
         = do
              let assigs = fixupStack stack0 stack2
-             (tmp_lbl, block) <- makeFixupBlock dflags sp0 l stack2 tscp assigs
+             (tmp_lbl, block) <- makeFixupBlock cfg sp0 l stack2 tscp assigs
              return (l, tmp_lbl, stack2, block)
 
         --   (b) if the successor is a proc point, save everything
@@ -555,7 +555,7 @@ handleLastNode dflags procpoints liveness cont_info stackmaps
                  (stack2, assigs) =
                       setupStackFrame platform l liveness (sm_ret_off stack0)
                                                         cont_args stack0
-             (tmp_lbl, block) <- makeFixupBlock dflags sp0 l stack2 tscp assigs
+             (tmp_lbl, block) <- makeFixupBlock cfg sp0 l stack2 tscp assigs
              return (l, tmp_lbl, stack2, block)
 
         --   (c) otherwise, the current StackMap is the StackMap for
@@ -569,16 +569,16 @@ handleLastNode dflags procpoints liveness cont_info stackmaps
               is_live (r,_) = r `elemRegSet` live
 
 
-makeFixupBlock :: DynFlags -> ByteOff -> Label -> StackMap
+makeFixupBlock :: CmmConfig -> ByteOff -> Label -> StackMap
                -> CmmTickScope -> [CmmNode O O]
                -> UniqSM (Label, [CmmBlock])
-makeFixupBlock dflags sp0 l stack tscope assigs
+makeFixupBlock cfg sp0 l stack tscope assigs
   | null assigs && sp0 == sm_sp stack = return (l, [])
   | otherwise = do
     tmp_lbl <- newBlockId
     let sp_off = sp0 - sm_sp stack
         block = blockJoin (CmmEntry tmp_lbl tscope)
-                          ( maybeAddSpAdj dflags sp0 sp_off
+                          ( maybeAddSpAdj cfg sp0 sp_off
                            $ blockFromList assigs )
                           (CmmBranch l)
     return (tmp_lbl, [block])
@@ -822,7 +822,7 @@ allocate platform ret_off live stackmap@StackMap{ sm_sp = sp0
 -- middle_post, because the Sp adjustment intervenes.
 --
 manifestSp
-   :: DynFlags
+   :: CmmConfig
    -> LabelMap StackMap  -- StackMaps for other blocks
    -> StackMap           -- StackMap for this block
    -> ByteOff            -- Sp on entry to the block
@@ -834,18 +834,18 @@ manifestSp
    -> [CmmBlock]         -- new blocks
    -> [CmmBlock]         -- final blocks with Sp manifest
 
-manifestSp dflags stackmaps stack0 sp0 sp_high
+manifestSp cfg stackmaps stack0 sp0 sp_high
            first middle_pre sp_off last fixup_blocks
   = final_block : fixup_blocks'
   where
     area_off = getAreaOff stackmaps
-    platform = targetPlatform dflags
+    platform = cmmPlatform cfg
 
     adj_pre_sp, adj_post_sp :: CmmNode e x -> CmmNode e x
     adj_pre_sp  = mapExpDeep (areaToSp platform sp0            sp_high area_off)
     adj_post_sp = mapExpDeep (areaToSp platform (sp0 - sp_off) sp_high area_off)
 
-    final_middle = maybeAddSpAdj dflags sp0 sp_off
+    final_middle = maybeAddSpAdj cfg sp0 sp_off
                  . blockFromList
                  . map adj_pre_sp
                  . elimStackStores stack0 stackmaps area_off
@@ -865,11 +865,12 @@ getAreaOff stackmaps (Young l) =
 
 
 maybeAddSpAdj
-  :: DynFlags -> ByteOff -> ByteOff -> Block CmmNode O O -> Block CmmNode O O
-maybeAddSpAdj dflags sp0 sp_off block =
+  :: CmmConfig -> ByteOff -> ByteOff -> Block CmmNode O O -> Block CmmNode O O
+maybeAddSpAdj cfg sp0 sp_off block =
   add_initial_unwind $ add_adj_unwind $ adj block
   where
-    platform = targetPlatform dflags
+    platform             = cmmPlatform            cfg
+    do_stk_unwinding_gen = cmmGenStackUnwindInstr cfg
     adj block
       | sp_off /= 0
       = block `blockSnoc` CmmAssign spReg (cmmOffset platform spExpr sp_off)
@@ -877,7 +878,7 @@ maybeAddSpAdj dflags sp0 sp_off block =
     -- Add unwind pseudo-instruction at the beginning of each block to
     -- document Sp level for debugging
     add_initial_unwind block
-      | debugLevel dflags > 0
+      | do_stk_unwinding_gen
       = CmmUnwind [(Sp, Just sp_unwind)] `blockCons` block
       | otherwise
       = block
@@ -886,7 +887,7 @@ maybeAddSpAdj dflags sp0 sp_off block =
     -- Add unwind pseudo-instruction right after the Sp adjustment
     -- if there is one.
     add_adj_unwind block
-      | debugLevel dflags > 0
+      | do_stk_unwinding_gen
       , sp_off /= 0
       = block `blockSnoc` CmmUnwind [(Sp, Just sp_unwind)]
       | otherwise
diff --git a/compiler/GHC/Cmm/Pipeline.hs b/compiler/GHC/Cmm/Pipeline.hs
index 7de0ce0cb8..270a281461 100644
--- a/compiler/GHC/Cmm/Pipeline.hs
+++ b/compiler/GHC/Cmm/Pipeline.hs
@@ -10,19 +10,20 @@ module GHC.Cmm.Pipeline (
 import GHC.Prelude
 
 import GHC.Cmm
-import GHC.Cmm.Lint
-import GHC.Cmm.Info.Build
-import GHC.Cmm.CommonBlockElim
-import GHC.Cmm.Switch.Implement
-import GHC.Cmm.ProcPoint
+import GHC.Cmm.Config
 import GHC.Cmm.ContFlowOpt
+import GHC.Cmm.CommonBlockElim
+import GHC.Cmm.Dataflow.Collections
+import GHC.Cmm.Info.Build
+import GHC.Cmm.Lint
 import GHC.Cmm.LayoutStack
+import GHC.Cmm.ProcPoint
 import GHC.Cmm.Sink
-import GHC.Cmm.Dataflow.Collections
+import GHC.Cmm.Switch.Implement
 
 import GHC.Types.Unique.Supply
 import GHC.Driver.Session
-import GHC.Driver.Backend
+import GHC.Driver.Config.Cmm
 import GHC.Utils.Error
 import GHC.Utils.Logger
 import GHC.Driver.Env
@@ -43,23 +44,23 @@ cmmPipeline
  -> IO (ModuleSRTInfo, CmmGroupSRTs) -- Output CPS transformed C--
 
 cmmPipeline hsc_env srtInfo prog = do
-  let logger = hsc_logger hsc_env
-  let dflags = hsc_dflags hsc_env
-  let forceRes (info, group) = info `seq` foldr (\decl r -> decl `seq` r) () group
-  let platform = targetPlatform dflags
+  let logger    = hsc_logger hsc_env
+  let cmmConfig = initCmmConfig (hsc_dflags hsc_env)
+  let forceRes (info, group) = info `seq` foldr seq () group
+  let platform = cmmPlatform cmmConfig
   withTimingSilent logger (text "Cmm pipeline") forceRes $ do
-     tops <- {-# SCC "tops" #-} mapM (cpsTop logger platform dflags) prog
+     tops <- {-# SCC "tops" #-} mapM (cpsTop logger platform cmmConfig) prog
 
      let (procs, data_) = partitionEithers tops
-     (srtInfo, cmms) <- {-# SCC "doSRTs" #-} doSRTs dflags srtInfo procs data_
+     (srtInfo, cmms) <- {-# SCC "doSRTs" #-} doSRTs cmmConfig srtInfo procs data_
      dumpWith logger Opt_D_dump_cmm_cps "Post CPS Cmm" FormatCMM (pdoc platform cmms)
 
      return (srtInfo, cmms)
 
 
-cpsTop :: Logger -> Platform -> DynFlags -> CmmDecl -> IO (Either (CAFEnv, [CmmDecl]) (CAFSet, CmmDecl))
+cpsTop :: Logger -> Platform -> CmmConfig -> CmmDecl -> IO (Either (CAFEnv, [CmmDecl]) (CAFSet, CmmDecl))
 cpsTop _logger platform _ p@(CmmData _ statics) = return (Right (cafAnalData platform statics, p))
-cpsTop logger platform dflags proc =
+cpsTop logger platform cfg proc =
     do
       ----------- Control-flow optimisations ----------------------------------
 
@@ -76,15 +77,17 @@ cpsTop logger platform dflags proc =
 
       ----------- Eliminate common blocks -------------------------------------
       g <- {-# SCC "elimCommonBlocks" #-}
-           condPass Opt_CmmElimCommonBlocks elimCommonBlocks g
+           condPass (cmmOptElimCommonBlks cfg) elimCommonBlocks g
                          Opt_D_dump_cmm_cbe "Post common block elimination"
 
       -- Any work storing block Labels must be performed _after_
       -- elimCommonBlocks
 
       ----------- Implement switches ------------------------------------------
-      g <- {-# SCC "createSwitchPlans" #-}
-           runUniqSM $ cmmImplementSwitchPlans (backend dflags) platform g
+      g <- if cmmDoCmmSwitchPlans cfg
+             then {-# SCC "createSwitchPlans" #-}
+                  runUniqSM $ cmmImplementSwitchPlans platform g
+             else pure g
       dump Opt_D_dump_cmm_switch "Post switch plan" g
 
       ----------- Proc points -------------------------------------------------
@@ -106,13 +109,13 @@ cpsTop logger platform dflags proc =
       (g, stackmaps) <-
            {-# SCC "layoutStack" #-}
            if do_layout
-              then runUniqSM $ cmmLayoutStack dflags proc_points entry_off g
+              then runUniqSM $ cmmLayoutStack cfg proc_points entry_off g
               else return (g, mapEmpty)
       dump Opt_D_dump_cmm_sp "Layout Stack" g
 
       ----------- Sink and inline assignments  --------------------------------
       g <- {-# SCC "sink" #-} -- See Note [Sinking after stack layout]
-           condPass Opt_CmmSink (cmmSink platform) g
+           condPass (cmmOptSink cfg) (cmmSink platform) g
                     Opt_D_dump_cmm_sink "Sink assignments"
 
       ------------- CAF analysis ----------------------------------------------
@@ -142,7 +145,7 @@ cpsTop logger platform dflags proc =
 
       ----------- Control-flow optimisations -----------------------------
       g <- {-# SCC "cmmCfgOpts(2)" #-}
-           return $ if gopt Opt_CmmControlFlow dflags
+           return $ if cmmOptControlFlow cfg
                     then map (cmmCfgOptsProc splitting_proc_points) g
                     else g
       g <- return (map removeUnreachableBlocksProc g)
@@ -151,13 +154,13 @@ cpsTop logger platform dflags proc =
 
       return (Left (cafEnv, g))
 
-  where dump = dumpGraph logger platform dflags
+  where dump = dumpGraph logger platform (cmmDoLinting cfg)
 
         dumps flag name
            = mapM_ (dumpWith logger flag name FormatCMM . pdoc platform)
 
-        condPass flag pass g dumpflag dumpname =
-            if gopt flag dflags
+        condPass do_opt pass g dumpflag dumpname =
+            if do_opt
                then do
                     g <- return $ pass g
                     dump dumpflag dumpname g
@@ -168,14 +171,7 @@ cpsTop logger platform dflags proc =
         -- tablesNextToCode is off.  The latter is because we have no
         -- label to put on info tables for basic blocks that are not
         -- the entry point.
-        splitting_proc_points = backend dflags /= NCG
-                             || not (platformTablesNextToCode platform)
-                             || -- Note [inconsistent-pic-reg]
-                                usingInconsistentPicReg
-        usingInconsistentPicReg
-           = case (platformArch platform, platformOS platform, positionIndependent dflags)
-             of   (ArchX86, OSDarwin, pic) -> pic
-                  _                        -> False
+        splitting_proc_points = cmmSplitProcPoints cfg
 
 -- Note [Sinking after stack layout]
 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -347,9 +343,9 @@ runUniqSM m = do
   return (initUs_ us m)
 
 
-dumpGraph :: Logger -> Platform -> DynFlags -> DumpFlag -> String -> CmmGraph -> IO ()
-dumpGraph logger platform dflags flag name g = do
-  when (gopt Opt_DoCmmLinting dflags) $ do_lint g
+dumpGraph :: Logger -> Platform -> Bool -> DumpFlag -> String -> CmmGraph -> IO ()
+dumpGraph logger platform do_linting flag name g = do
+  when do_linting $ do_lint g
   dumpWith logger flag name FormatCMM (pdoc platform g)
  where
   do_lint g = case cmmLintGraph platform g of
diff --git a/compiler/GHC/Cmm/Switch/Implement.hs b/compiler/GHC/Cmm/Switch/Implement.hs
index 7b0ad6107a..87dfc1cdaa 100644
--- a/compiler/GHC/Cmm/Switch/Implement.hs
+++ b/compiler/GHC/Cmm/Switch/Implement.hs
@@ -6,7 +6,6 @@ where
 
 import GHC.Prelude
 
-import GHC.Driver.Backend
 import GHC.Platform
 import GHC.Cmm.Dataflow.Block
 import GHC.Cmm.BlockId
@@ -32,11 +31,10 @@ import GHC.Utils.Monad (concatMapM)
 
 -- | Traverses the 'CmmGraph', making sure that 'CmmSwitch' are suitable for
 -- code generation.
-cmmImplementSwitchPlans :: Backend -> Platform -> CmmGraph -> UniqSM CmmGraph
-cmmImplementSwitchPlans backend platform g
+cmmImplementSwitchPlans :: Platform -> CmmGraph -> UniqSM CmmGraph
+cmmImplementSwitchPlans platform g =
     -- Switch generation done by backend (LLVM/C)
-    | backendSupportsSwitch backend = return g
-    | otherwise = do
+    do
     blocks' <- concatMapM (visitSwitches platform) (toBlockList g)
     return $ ofBlockList (g_entry g) blocks'
 
diff --git a/compiler/GHC/CmmToAsm/PIC.hs b/compiler/GHC/CmmToAsm/PIC.hs
index 10ddaa1f5f..8a728102e5 100644
--- a/compiler/GHC/CmmToAsm/PIC.hs
+++ b/compiler/GHC/CmmToAsm/PIC.hs
@@ -209,6 +209,13 @@ absoluteLabel lbl
 -- pointers, code stubs and GOT offsets look like is located in the
 -- module CLabel.
 
+-- | Helper to check whether the data resides in a DLL or not, see @labelDynamic@
+ncgLabelDynamic :: NCGConfig -> CLabel -> Bool
+ncgLabelDynamic config = labelDynamic (ncgThisModule config)
+                                      (ncgPlatform config)
+                                      (ncgExternalDynamicRefs config)
+
+
 -- We have to decide which labels need to be accessed
 -- indirectly or via a piece of stub code.
 data LabelAccessStyle
@@ -247,7 +254,7 @@ howToAccessLabel config _arch OSMinGW32 _kind lbl
 
         -- If the target symbol is in another PE we need to access it via the
         --      appropriate __imp_SYMBOL pointer.
-        | labelDynamic config lbl
+        | ncgLabelDynamic config lbl
         = AccessViaSymbolPtr
 
         -- Target symbol is in the same PE as the caller, so just access it directly.
@@ -262,7 +269,7 @@ howToAccessLabel config ArchAArch64 _os _kind lbl
         | not (ncgExternalDynamicRefs config)
         = AccessDirectly
 
-        | labelDynamic config lbl
+        | ncgLabelDynamic config lbl
         = AccessViaSymbolPtr
 
         | otherwise
@@ -279,7 +286,7 @@ howToAccessLabel config ArchAArch64 _os _kind lbl
 --
 howToAccessLabel config arch OSDarwin DataReference lbl
         -- data access to a dynamic library goes via a symbol pointer
-        | labelDynamic config lbl
+        | ncgLabelDynamic config lbl
         = AccessViaSymbolPtr
 
         -- when generating PIC code, all cross-module data references must
@@ -300,7 +307,7 @@ howToAccessLabel config arch OSDarwin JumpReference lbl
         -- stack alignment is only right for regular calls.
         -- Therefore, we have to go via a symbol pointer:
         | arch == ArchX86 || arch == ArchX86_64 || arch == ArchAArch64
-        , labelDynamic config lbl
+        , ncgLabelDynamic config lbl
         = AccessViaSymbolPtr
 
 
@@ -310,7 +317,7 @@ howToAccessLabel config arch OSDarwin _kind lbl
         -- them automatically, neither on Aarch64 (arm64).
         | arch /= ArchX86_64
         , arch /= ArchAArch64
-        , labelDynamic config lbl
+        , ncgLabelDynamic config lbl
         = AccessViaStub
 
         | otherwise
@@ -362,7 +369,7 @@ howToAccessLabel config arch os DataReference lbl
         | osElfTarget os
         = case () of
             -- A dynamic label needs to be accessed via a symbol pointer.
-          _ | labelDynamic config lbl
+          _ | ncgLabelDynamic config lbl
             -> AccessViaSymbolPtr
 
             -- For PowerPC32 -fPIC, we have to access even static data
@@ -390,18 +397,19 @@ howToAccessLabel config arch os DataReference lbl
 
 howToAccessLabel config arch os CallReference lbl
         | osElfTarget os
-        , labelDynamic config lbl && not (ncgPIC config)
+        , ncgLabelDynamic config lbl
+        , not (ncgPIC config)
         = AccessDirectly
 
         | osElfTarget os
         , arch /= ArchX86
-        , labelDynamic config lbl
+        , ncgLabelDynamic config lbl
         , ncgPIC config
         = AccessViaStub
 
 howToAccessLabel config _arch os _kind lbl
         | osElfTarget os
-        = if labelDynamic config lbl
+        = if ncgLabelDynamic config lbl
             then AccessViaSymbolPtr
             else AccessDirectly
 
diff --git a/compiler/GHC/Driver/Config/Cmm.hs b/compiler/GHC/Driver/Config/Cmm.hs
new file mode 100644
index 0000000000..38bab62048
--- /dev/null
+++ b/compiler/GHC/Driver/Config/Cmm.hs
@@ -0,0 +1,33 @@
+module GHC.Driver.Config.Cmm
+  ( initCmmConfig
+  ) where
+
+import GHC.Cmm.Config
+import GHC.Cmm.Switch (backendSupportsSwitch)
+
+import GHC.Driver.Session
+import GHC.Driver.Backend
+
+import GHC.Platform
+
+import GHC.Prelude
+
+initCmmConfig :: DynFlags -> CmmConfig
+initCmmConfig dflags = CmmConfig
+  { cmmProfile             = targetProfile                dflags
+  , cmmOptControlFlow      = gopt Opt_CmmControlFlow      dflags
+  , cmmDoLinting           = gopt Opt_DoCmmLinting        dflags
+  , cmmOptElimCommonBlks   = gopt Opt_CmmElimCommonBlocks dflags
+  , cmmOptSink             = gopt Opt_CmmSink             dflags
+  , cmmGenStackUnwindInstr = debugLevel dflags > 0
+  , cmmExternalDynamicRefs = gopt Opt_ExternalDynamicRefs dflags
+  , cmmDoCmmSwitchPlans    = not . backendSupportsSwitch . backend $ dflags
+  , cmmSplitProcPoints     = (backend dflags /= NCG)
+                             || not (platformTablesNextToCode platform)
+                             || usingInconsistentPicReg
+  }
+  where platform                = targetPlatform dflags
+        usingInconsistentPicReg =
+          case (platformArch platform, platformOS platform, positionIndependent dflags)
+          of   (ArchX86, OSDarwin, pic) -> pic
+               _                        -> False
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index db3f5f3926..51315c8b75 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -167,6 +167,7 @@ Library
         GHC.Cmm.CallConv
         GHC.Cmm.CLabel
         GHC.Cmm.CommonBlockElim
+        GHC.Cmm.Config
         GHC.Cmm.ContFlowOpt
         GHC.Cmm.Dataflow
         GHC.Cmm.Dataflow.Block
@@ -386,6 +387,7 @@ Library
         GHC.Driver.CmdLine
         GHC.Driver.CodeOutput
         GHC.Driver.Config
+        GHC.Driver.Config.Cmm
         GHC.Driver.Config.CmmToAsm
         GHC.Driver.Config.CmmToLlvm
         GHC.Driver.Config.Diagnostic
diff --git a/testsuite/tests/count-deps/CountDepsAst.stdout b/testsuite/tests/count-deps/CountDepsAst.stdout
index b557778846..c4d629069c 100644
--- a/testsuite/tests/count-deps/CountDepsAst.stdout
+++ b/testsuite/tests/count-deps/CountDepsAst.stdout
@@ -1,4 +1,4 @@
-Found 277 Language.Haskell.Syntax module dependencies
+Found 276 Language.Haskell.Syntax module dependencies
 GHC.Builtin.Names
 GHC.Builtin.PrimOps
 GHC.Builtin.Types
@@ -18,7 +18,6 @@ GHC.Cmm.Node
 GHC.Cmm.Switch
 GHC.Cmm.Type
 GHC.CmmToAsm.CFG.Weight
-GHC.CmmToAsm.Config
 GHC.Core
 GHC.Core.Class
 GHC.Core.Coercion
diff --git a/testsuite/tests/count-deps/CountDepsParser.stdout b/testsuite/tests/count-deps/CountDepsParser.stdout
index 1e86aeb777..457e42da8e 100644
--- a/testsuite/tests/count-deps/CountDepsParser.stdout
+++ b/testsuite/tests/count-deps/CountDepsParser.stdout
@@ -1,4 +1,4 @@
-Found 283 GHC.Parser module dependencies
+Found 282 GHC.Parser module dependencies
 GHC.Builtin.Names
 GHC.Builtin.PrimOps
 GHC.Builtin.Types
@@ -18,7 +18,6 @@ GHC.Cmm.Node
 GHC.Cmm.Switch
 GHC.Cmm.Type
 GHC.CmmToAsm.CFG.Weight
-GHC.CmmToAsm.Config
 GHC.Core
 GHC.Core.Class
 GHC.Core.Coercion