split the CmmGraph constructor interface from the representation

Interface MkZipCfgCmm should now be sufficient for all construction
needs, though some identifiers are re-exported from (and explained in)
MkZipCfg.  ZipCfgCmmRep should be used only by modules involved in
analysis, optimization, or translation of Cmm programs.

13 files changed, 143 insertions, 114 deletions

diff --git a/compiler/cmm/CmmCPSZ.hs b/compiler/cmm/CmmCPSZ.hs
index afa1533efa..9410304b68 100644
--- a/compiler/cmm/CmmCPSZ.hs
+++ b/compiler/cmm/CmmCPSZ.hs
@@ -19,7 +19,7 @@ import Outputable
 import PprCmmZ()
 import UniqSupply
 import ZipCfg hiding (zip, unzip)
-import ZipCfgCmm
+import ZipCfgCmmRep
 import ZipDataflow
 
 -----------------------------------------------------------------------------
diff --git a/compiler/cmm/CmmContFlowOpt.hs b/compiler/cmm/CmmContFlowOpt.hs
index 149d33e0b3..7581d81fdb 100644
--- a/compiler/cmm/CmmContFlowOpt.hs
+++ b/compiler/cmm/CmmContFlowOpt.hs
@@ -8,7 +8,7 @@ where
 import Cmm
 import CmmTx
 import qualified ZipCfg as G
-import ZipCfgCmm
+import ZipCfgCmmRep
 import Maybes
 import Util
 import UniqFM
diff --git a/compiler/cmm/CmmCvt.hs b/compiler/cmm/CmmCvt.hs
index 7b22958f24..655f2d3373 100644
--- a/compiler/cmm/CmmCvt.hs
+++ b/compiler/cmm/CmmCvt.hs
@@ -6,8 +6,8 @@ module CmmCvt
 where
 import Cmm
 import CmmExpr
-import ZipCfgCmm
-import MkZipCfg 
+import MkZipCfgCmm hiding (CmmGraph)
+import ZipCfgCmmRep -- imported for reverse conversion
 import CmmZipUtil
 import FastString
 import Outputable
@@ -39,7 +39,7 @@ toZgraph fun_name g@(ListGraph (BasicBlock id ss : other_blocks)) =
         mkStmts (CmmCall f res args CmmUnsafe CmmMayReturn : ss) =
                       mkUnsafeCall f res args     <*> mkStmts ss
         mkStmts (CmmCondBranch e l : fbranch) =
-            mkIfThenElse (mkCbranch e) (mkBranch l) (mkStmts fbranch)
+            mkCmmIfThenElse e (mkBranch l) (mkStmts fbranch)
         mkStmts (last : []) = mkLast last
         mkStmts []          = bad "fell off end"
         mkStmts (_ : _ : _) = bad "last node not at end"
diff --git a/compiler/cmm/CmmLiveZ.hs b/compiler/cmm/CmmLiveZ.hs
index 66cb3f1541..3df8a18f70 100644
--- a/compiler/cmm/CmmLiveZ.hs
+++ b/compiler/cmm/CmmLiveZ.hs
@@ -16,7 +16,7 @@ import PprCmm()
 import PprCmmZ()
 import UniqSet
 import ZipDataflow
-import ZipCfgCmm
+import ZipCfgCmmRep
 
 -----------------------------------------------------------------------------
 -- Calculating what variables are live on entry to a basic block
diff --git a/compiler/cmm/CmmProcPointZ.hs b/compiler/cmm/CmmProcPointZ.hs
index c5d7177360..0a87a65357 100644
--- a/compiler/cmm/CmmProcPointZ.hs
+++ b/compiler/cmm/CmmProcPointZ.hs
@@ -22,7 +22,7 @@ import Panic
 import UniqFM
 import UniqSet
 import ZipCfg
-import ZipCfgCmm 
+import ZipCfgCmmRep
 import ZipDataflow
 
 -- Compute a minimal set of proc points for a control-flow graph.
diff --git a/compiler/cmm/CmmSpillReload.hs b/compiler/cmm/CmmSpillReload.hs
index 00372e59ad..b588c46af6 100644
--- a/compiler/cmm/CmmSpillReload.hs
+++ b/compiler/cmm/CmmSpillReload.hs
@@ -25,7 +25,7 @@ import Panic
 import PprCmm()
 import UniqSet
 import ZipCfg
-import ZipCfgCmm
+import ZipCfgCmmRep
 import ZipDataflow
 
 -- The point of this module is to insert spills and reloads to
diff --git a/compiler/cmm/MkZipCfg.hs b/compiler/cmm/MkZipCfg.hs
index 3d6f3445af..dc19197880 100644
--- a/compiler/cmm/MkZipCfg.hs
+++ b/compiler/cmm/MkZipCfg.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE ScopedTypeVariables #-}
 {-# OPTIONS -Wall -fno-warn-name-shadowing #-}
 module MkZipCfg
     ( AGraph, (<*>), emptyAGraph, withFreshLabel, withUnique
diff --git a/compiler/cmm/MkZipCfgCmm.hs b/compiler/cmm/MkZipCfgCmm.hs
new file mode 100644
index 0000000000..6792559aee
--- /dev/null
+++ b/compiler/cmm/MkZipCfgCmm.hs
@@ -0,0 +1,84 @@
+{-# OPTIONS -Wall -fno-warn-name-shadowing #-}
+
+-- This is the module to import to be able to build C-- programs.
+-- It should not be necessary to import MkZipCfg or ZipCfgCmmRep.
+-- If you find it necessary to import these other modules, please
+-- complain to Norman Ramsey.
+
+module MkZipCfgCmm
+  ( mkNop, mkAssign, mkStore, mkCall, mkUnsafeCall, mkFinalCall
+         , mkJump, mkCbranch, mkSwitch, mkReturn, mkComment, mkCmmIfThenElse
+         , mkCmmWhileDo
+  , (<*>), mkLabel, mkBranch
+  , emptyAGraph, withFreshLabel, withUnique, outOfLine
+  , lgraphOfAGraph, graphOfAGraph, labelAGraph
+  , CmmZ, CmmTopZ, CmmGraph, CmmBlock, CmmAGraph, Middle, Last, Convention(..)
+  )
+where
+
+#include "HsVersions.h"
+
+import CmmExpr
+import Cmm ( GenCmm(..), GenCmmTop(..), CmmStatic, CmmInfo
+           , CmmCallTarget(..), CmmActuals, CmmFormals
+           )
+import ZipCfgCmmRep hiding (CmmGraph, CmmAGraph, CmmBlock, CmmZ, CmmTopZ)
+  -- ^ to make this module more self-contained, these definitions are duplicated below
+import PprCmm()
+
+import ClosureInfo
+import FastString
+import ForeignCall
+import ZipCfg 
+import MkZipCfg
+
+type CmmGraph  = LGraph Middle Last
+type CmmAGraph = AGraph Middle Last
+type CmmBlock  = Block  Middle Last
+type CmmZ      = GenCmm    CmmStatic CmmInfo CmmGraph
+type CmmTopZ   = GenCmmTop CmmStatic CmmInfo CmmGraph
+
+mkNop        :: CmmAGraph
+mkAssign     :: CmmReg  -> CmmExpr -> CmmAGraph
+mkStore      :: CmmExpr -> CmmExpr -> CmmAGraph
+mkCall       :: CmmCallTarget -> CmmFormals -> CmmActuals -> C_SRT -> CmmAGraph
+mkUnsafeCall :: CmmCallTarget -> CmmFormals -> CmmActuals -> CmmAGraph
+mkFinalCall  :: CmmCallTarget -> CmmActuals -> CmmAGraph -- never returns
+mkJump       :: CmmExpr -> CmmActuals -> CmmAGraph
+mkCbranch    :: CmmExpr -> BlockId -> BlockId -> CmmAGraph
+mkSwitch     :: CmmExpr -> [Maybe BlockId] -> CmmAGraph
+mkReturn     :: CmmActuals -> CmmAGraph
+mkComment    :: FastString -> CmmAGraph
+
+-- Not to be forgotten, but exported by MkZipCfg:
+--mkBranch      :: BlockId -> CmmAGraph
+--mkLabel       :: BlockId -> CmmAGraph
+mkCmmIfThenElse :: CmmExpr -> CmmAGraph -> CmmAGraph -> CmmAGraph
+mkCmmWhileDo    :: CmmExpr -> CmmAGraph -> CmmAGraph 
+
+--------------------------------------------------------------------------
+
+mkCmmIfThenElse e = mkIfThenElse (mkCbranch e)
+mkCmmWhileDo    e = mkWhileDo    (mkCbranch e)
+
+
+-- ================ IMPLEMENTATION ================--
+
+mkNop                     = mkMiddle $ MidNop
+mkComment fs              = mkMiddle $ MidComment fs
+mkAssign l r              = mkMiddle $ MidAssign l r
+mkStore  l r              = mkMiddle $ MidStore  l r
+
+mkJump e args             = mkLast   $ LastJump e args
+mkCbranch pred ifso ifnot = mkLast   $ LastCondBranch pred ifso ifnot
+mkReturn actuals          = mkLast   $ LastReturn actuals
+mkSwitch e tbl            = mkLast   $ LastSwitch e tbl
+
+mkUnsafeCall tgt results actuals = mkMiddle $ MidUnsafeCall tgt results actuals
+mkFinalCall  tgt actuals         = mkLast   $ LastCall      tgt actuals Nothing
+
+mkCall tgt results actuals srt =
+  withFreshLabel "call successor" $ \k ->
+    mkLast (LastCall tgt actuals (Just k)) <*>
+    mkLabel k <*>
+    mkMiddle (CopyIn (Result CmmCallConv) results srt)
diff --git a/compiler/cmm/PprCmmZ.hs b/compiler/cmm/PprCmmZ.hs
index c6eb4ae8fa..fa930bd88e 100644
--- a/compiler/cmm/PprCmmZ.hs
+++ b/compiler/cmm/PprCmmZ.hs
@@ -10,7 +10,7 @@ import Cmm
 import CmmExpr
 import PprCmm()
 import Outputable
-import qualified ZipCfgCmm as G
+import qualified ZipCfgCmmRep as G
 import qualified ZipCfg as Z
 import CmmZipUtil
 
diff --git a/compiler/cmm/StackColor.hs b/compiler/cmm/StackColor.hs
index e3b6ba8f5b..c9cb856651 100644
--- a/compiler/cmm/StackColor.hs
+++ b/compiler/cmm/StackColor.hs
@@ -9,7 +9,7 @@ import DFMonad
 import qualified GraphOps
 import MachOp
 import ZipCfg
-import ZipCfgCmm
+import ZipCfgCmmRep
 import ZipDataflow
 
 import Maybes
diff --git a/compiler/cmm/ZipCfg.hs b/compiler/cmm/ZipCfg.hs
index e8fc5edfb3..0c2b84b0fe 100644
--- a/compiler/cmm/ZipCfg.hs
+++ b/compiler/cmm/ZipCfg.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE ScopedTypeVariables #-}
 {-# OPTIONS -Wall -fno-warn-name-shadowing #-}
 module ZipCfg
     ( BlockId(..), freshBlockId
@@ -67,7 +66,7 @@ or during optimization (see module 'ZipDataflow').
 
 A graph is parameterized over the types of middle and last nodes.  Each of
 these types will typically be instantiated with a subset of C-- statements
-(see module 'ZipCfgCmm') or a subset of machine instructions (yet to be
+(see module 'ZipCfgCmmRep') or a subset of machine instructions (yet to be
 implemented as of August 2007).
 
 
@@ -210,7 +209,7 @@ to_block_list :: LGraph m l -> [Block m l]  -- N log N
 -- The postorder depth-first-search order means the list is in roughly
 -- first-to-last order, as suitable for use in a forward dataflow problem.
 
-postorder_dfs :: forall m l . LastNode l => LGraph m l -> [Block m l]
+postorder_dfs :: LastNode l => LGraph m l -> [Block m l]
 
 -- | For layout, we fold over pairs of [[Block m l]] and [[Maybe BlockId]] 
 -- in layout order.  The [[BlockId]], if any, identifies the block that
@@ -225,13 +224,11 @@ fold_blocks :: (Block m l -> a -> a) -> a -> LGraph m l -> a
 
 map_nodes :: (BlockId -> BlockId) -> (m -> m') -> (l -> l') -> LGraph m l -> LGraph m' l'
    -- mapping includes the entry id!
-translate :: forall m l m' l' .
-             (m -> UniqSM (LGraph m' l')) -> (l -> UniqSM (LGraph m' l')) ->
+translate :: (m -> UniqSM (LGraph m' l')) -> (l -> UniqSM (LGraph m' l')) ->
              LGraph m l -> UniqSM (LGraph m' l')
 
 {-
-translateA :: forall m l m' l' .
-              (m -> Agraph m' l') -> (l -> AGraph m' l') -> LGraph m l -> LGraph m' l'
+translateA :: (m -> Agraph m' l') -> (l -> AGraph m' l') -> LGraph m l -> LGraph m' l'
 -}
 
 ------------------- Last nodes
@@ -373,7 +370,7 @@ postorder_dfs g@(LGraph _ blocks) =
   let FGraph _ eblock _ = entry g
   in  vnode (zip eblock) (\acc _visited -> acc) [] emptyBlockSet
   where
-    vnode :: Block m l -> ([Block m l] -> BlockSet -> a) -> [Block m l] -> BlockSet ->a
+    -- vnode :: Block m l -> ([Block m l] -> BlockSet -> a) -> [Block m l] -> BlockSet ->a
     vnode block@(Block id _) cont acc visited =
         if elemBlockSet id visited then
             cont acc visited
@@ -495,13 +492,13 @@ translate txm txl (LGraph eid blocks) =
     do blocks' <- foldUFM txblock (return emptyBlockEnv) blocks
        return $ LGraph eid blocks'
     where
-      txblock ::
-        Block m l -> UniqSM (BlockEnv (Block m' l')) -> UniqSM (BlockEnv (Block m' l'))
+      -- txblock ::
+      -- Block m l -> UniqSM (BlockEnv (Block m' l')) -> UniqSM (BlockEnv (Block m' l'))
       txblock (Block id t) expanded =
         do blocks' <- expanded
            txtail (ZFirst id) t blocks'
-      txtail :: ZHead m' -> ZTail m l -> BlockEnv (Block m' l') ->
-                UniqSM (BlockEnv (Block m' l'))
+      -- txtail :: ZHead m' -> ZTail m l -> BlockEnv (Block m' l') ->
+      --           UniqSM (BlockEnv (Block m' l'))
       txtail h (ZTail m t) blocks' =
         do m' <- txm m 
            let (g, h') = splice_head h m' 
diff --git a/compiler/cmm/ZipCfgCmm.hs b/compiler/cmm/ZipCfgCmmRep.hs
index 2a68502bb6..71e206e4f6 100644
--- a/compiler/cmm/ZipCfgCmm.hs
+++ b/compiler/cmm/ZipCfgCmmRep.hs
@@ -1,10 +1,12 @@
 {-# OPTIONS -Wall -fno-warn-name-shadowing #-}
-module ZipCfgCmm
-  ( mkNop, mkAssign, mkStore, mkCall, mkUnsafeCall, mkFinalCall
-         , mkJump, mkCbranch, mkSwitch, mkReturn, mkComment, mkCmmIfThenElse
-         , mkCmmWhileDo
-  , mkCopyIn, mkCopyOut
-  , CmmZ, CmmTopZ, CmmGraph, CmmBlock, CmmAGraph, Middle(..), Last(..), Convention(..)
+
+-- This module is pure representation and should be imported only by
+-- clients that need to manipulate representation and know what
+-- they're doing.  Clients that need to create flow graphs should
+-- instead import MkZipCfgCmm.
+
+module ZipCfgCmmRep
+  ( CmmZ, CmmTopZ, CmmGraph, CmmBlock, CmmAGraph, Middle(..), Last(..), Convention(..)
   )
 where
 
@@ -37,38 +39,6 @@ type CmmBlock  = Block  Middle Last
 type CmmZ      = GenCmm    CmmStatic CmmInfo CmmGraph
 type CmmTopZ   = GenCmmTop CmmStatic CmmInfo CmmGraph
 
-mkNop        :: CmmAGraph
-mkAssign     :: CmmReg  -> CmmExpr -> CmmAGraph
-mkStore      :: CmmExpr -> CmmExpr -> CmmAGraph
-mkCall       :: CmmCallTarget -> CmmFormals -> CmmActuals -> C_SRT -> CmmAGraph
-mkUnsafeCall :: CmmCallTarget -> CmmFormals -> CmmActuals -> CmmAGraph
-mkFinalCall  :: CmmCallTarget -> CmmActuals -> CmmAGraph -- never returns
-mkJump       :: CmmExpr -> CmmActuals -> CmmAGraph
-mkCbranch    :: CmmExpr -> BlockId -> BlockId -> CmmAGraph
-mkSwitch     :: CmmExpr -> [Maybe BlockId] -> CmmAGraph
-mkReturn     :: CmmActuals -> CmmAGraph
-mkComment    :: FastString -> CmmAGraph
-
--- Not to be forgotten, but exported by MkZipCfg:
---mkBranch      :: BlockId -> CmmAGraph
---mkLabel       :: BlockId -> CmmAGraph
-mkCmmIfThenElse :: CmmExpr -> CmmAGraph -> CmmAGraph -> CmmAGraph
-mkCmmWhileDo    :: CmmExpr -> CmmAGraph -> CmmAGraph 
-
---------------------------------------------------------------------------
-
-mkCmmIfThenElse e = mkIfThenElse (mkCbranch e)
-mkCmmWhileDo    e = mkWhileDo    (mkCbranch e)
-
-mkCopyIn     :: Convention -> CmmFormals -> C_SRT -> CmmAGraph
-mkCopyOut    :: Convention -> CmmFormals -> CmmAGraph
-
-  -- ^ XXX: Simon or Simon thinks maybe the hints are being abused and
-  -- we should have CmmFormalsWithoutKinds here, but for now it is CmmFormals
-  -- for consistency with the rest of the back end ---NR
-
-mkComment fs = mkMiddle (MidComment fs)
-
 data Middle
   = MidNop
   | MidComment FastString
@@ -142,29 +112,6 @@ the dataflow fact for the proc-point calculation, but it should make
 things easier in many other respects.  
 -}
 
-
--- ================ IMPLEMENTATION ================--
-
-mkNop                     = mkMiddle $ MidNop
-mkAssign l r              = mkMiddle $ MidAssign l r
-mkStore  l r              = mkMiddle $ MidStore  l r
-mkCopyIn  conv args srt   = mkMiddle $ CopyIn  conv args srt
-mkCopyOut conv args       = mkMiddle $ CopyOut conv args 
-
-mkJump e args             = mkLast   $ LastJump e args
-mkCbranch pred ifso ifnot = mkLast   $ LastCondBranch pred ifso ifnot
-mkReturn actuals          = mkLast   $ LastReturn actuals
-mkSwitch e tbl            = mkLast   $ LastSwitch e tbl
-
-mkUnsafeCall tgt results actuals = mkMiddle $ MidUnsafeCall tgt results actuals
-mkFinalCall  tgt actuals         = mkLast   $ LastCall      tgt actuals Nothing
-
-mkCall tgt results actuals srt =
-  withFreshLabel "call successor" $ \k ->
-    mkLast (LastCall tgt actuals (Just k)) <*>
-    mkLabel k <*>
-    mkCopyIn (Result CmmCallConv) results srt
-
 instance HavingSuccessors Last where
     succs = cmmSuccs
     fold_succs = fold_cmm_succs
diff --git a/compiler/cmm/ZipDataflow.hs b/compiler/cmm/ZipDataflow.hs
index 8a8315ff24..2ce7a25eb9 100644
--- a/compiler/cmm/ZipDataflow.hs
+++ b/compiler/cmm/ZipDataflow.hs
@@ -1,5 +1,5 @@
 {-# OPTIONS -Wall -fno-warn-name-shadowing #-}
-{-# LANGUAGE ScopedTypeVariables, MultiParamTypeClasses #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
 module ZipDataflow
   ( Answer(..)
   , BComputation(..), BAnalysis, BTransformation, BFunctionalTransformation
@@ -177,9 +177,9 @@ It's possible we could make these things more regular.
 
 -- | The analysis functions set properties on unique IDs.
 
-run_b_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable a) =>
+run_b_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
               BAnalysis m l a ->      LGraph m l -> DFA a ()
-run_f_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable a) =>
+run_f_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
               FAnalysis m l a -> a -> LGraph m l -> DFA a ()
                               -- ^ extra parameter is the entry fact
 
@@ -208,10 +208,10 @@ fold_edge_facts_with_nodes_b :: LastNode l
 
 class (Outputable m, Outputable l, LastNode l, Outputable (LGraph m l)) => DebugNodes m l
 
-refine_f_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable a) =>
+refine_f_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
         FAnalysis m l a -> LGraph m l -> DFA a () -> DFA a ()
 
-refine_b_anal :: forall m l a . (DebugNodes m l, LastNode l, Outputable a) =>
+refine_b_anal :: (DebugNodes m l, LastNode l, Outputable a) =>
         BAnalysis m l a -> LGraph m l -> DFA a () -> DFA a ()
 
 b_rewrite :: (DebugNodes m l, Outputable a) =>
@@ -352,14 +352,14 @@ comp_with_exit_b comp exit_fact =
 -- Rewrite should always use exactly one of these monadic operations.
 
 solve_graph_b ::
-    forall m l a . (DebugNodes m l, Outputable a) =>
-                   BPass m l a -> OptimizationFuel -> G.LGraph m l -> a -> DFM a (OptimizationFuel, a)
+    (DebugNodes m l, Outputable a) =>
+    BPass m l a -> OptimizationFuel -> G.LGraph m l -> a -> DFM a (OptimizationFuel, a)
 solve_graph_b comp fuel graph exit_fact =
     general_backward (comp_with_exit_b comp exit_fact) fuel graph
   where
-    general_backward :: BPass m l a -> OptimizationFuel -> G.LGraph m l -> DFM a (OptimizationFuel, a)
+    -- general_backward :: BPass m l a -> OptimizationFuel -> G.LGraph m l -> DFM a (OptimizationFuel, a)
     general_backward comp fuel graph = 
-      let set_block_fact :: OptimizationFuel -> G.Block m l -> DFM a OptimizationFuel
+      let -- set_block_fact :: OptimizationFuel -> G.Block m l -> DFM a OptimizationFuel
           set_block_fact fuel b =
               do { (fuel, block_in) <-
                         let (h, l) = G.goto_end (G.unzip b) in
@@ -423,8 +423,8 @@ The tail is in final form; the head is still to be rewritten.
 -}
 
 solve_and_rewrite_b ::
-  forall m l a. (DebugNodes m l, Outputable a) =>
-         BPass m l a -> OptimizationFuel -> LGraph m l -> a -> DFM a (OptimizationFuel, a, LGraph m l)
+  (DebugNodes m l, Outputable a) =>
+  BPass m l a -> OptimizationFuel -> LGraph m l -> a -> DFM a (OptimizationFuel, a, LGraph m l)
 
 solve_and_rewrite_b comp fuel graph exit_fact =
   do { (_, a) <- solve_graph_b comp fuel graph exit_fact -- pass 1
@@ -441,9 +441,9 @@ solve_and_rewrite_b comp fuel graph exit_fact =
     eid = G.gr_entry graph
     backward_rewrite comp fuel graph =
       rewrite_blocks comp fuel emptyBlockEnv $ reverse (G.postorder_dfs graph)
-    rewrite_blocks ::
-      BPass m l a -> OptimizationFuel ->
-      BlockEnv (Block m l) -> [Block m l] -> DFM a (OptimizationFuel,G.LGraph m l)
+    -- rewrite_blocks ::
+    --   BPass m l a -> OptimizationFuel ->
+    --   BlockEnv (Block m l) -> [Block m l] -> DFM a (OptimizationFuel,G.LGraph m l)
     rewrite_blocks _comp fuel rewritten [] = return (fuel, G.LGraph eid rewritten)
     rewrite_blocks  comp fuel rewritten (b:bs) =
       let rewrite_next_block fuel =
@@ -460,8 +460,8 @@ solve_and_rewrite_b comp fuel graph exit_fact =
                    ; -- continue at entry of g
                      propagate fuel h a t rewritten'
                    } 
-          propagate :: OptimizationFuel -> G.ZHead m -> a -> G.ZTail m l ->
-                       BlockEnv (Block m l) -> DFM a (OptimizationFuel, G.LGraph m l)
+          -- propagate :: OptimizationFuel -> G.ZHead m -> a -> G.ZTail m l ->
+          --              BlockEnv (Block m l) -> DFM a (OptimizationFuel, G.LGraph m l)
           propagate fuel (G.ZHead h m) out tail rewritten =
               bc_middle_in comp out m fuel >>= \x -> case x of
                 Dataflow a -> propagate fuel h a (G.ZTail m tail) rewritten
@@ -612,9 +612,9 @@ comp_with_exit_f comp exit_fact_id = comp { fc_exit_outs = exit_outs }
 -- | Given [[comp_with_exit_f]], we can now solve a graph simply by doing a
 -- forward analysis on the modified computation.
 solve_graph_f ::
-    forall m l a . (DebugNodes m l, Outputable a) =>
-                   FPass m l a -> OptimizationFuel -> G.LGraph m l -> a ->
-                   DFM a (OptimizationFuel, a, LastOutFacts a)
+    (DebugNodes m l, Outputable a) =>
+    FPass m l a -> OptimizationFuel -> G.LGraph m l -> a ->
+    DFM a (OptimizationFuel, a, LastOutFacts a)
 solve_graph_f comp fuel g in_fact =
   do { exit_fact_id <- freshBlockId "proxy for exit node"
      ; fuel <- general_forward (comp_with_exit_f comp exit_fact_id) fuel in_fact g
@@ -623,11 +623,11 @@ solve_graph_f comp fuel g in_fact =
      ; forgetFact exit_fact_id -- close space leak
      ; return (fuel, a, LastOutFacts outs) }
   where
-    general_forward :: FPass m l a -> OptimizationFuel -> a -> G.LGraph m l -> DFM a OptimizationFuel
+    -- general_forward :: FPass m l a -> OptimizationFuel -> a -> G.LGraph m l -> DFM a OptimizationFuel
     general_forward comp fuel entry_fact graph =
       let blocks = G.postorder_dfs g
           is_local id = isJust $ lookupBlockEnv (G.gr_blocks g) id
-          set_or_save :: LastOutFacts a -> DFM a ()
+          -- set_or_save :: LastOutFacts a -> DFM a ()
           set_or_save (LastOutFacts l) = mapM_ set_or_save_one l
           set_or_save_one (id, a) =
             if is_local id then setFact id a else addLastOutFact (id, a)
@@ -677,8 +677,9 @@ between a head and tail.
 The tail is in final form; the head is still to be rewritten.
 -}
 solve_and_rewrite_f ::
-  forall m l a . (DebugNodes m l, Outputable a) =>
-         FPass m l a -> OptimizationFuel -> LGraph m l -> a -> DFM a (OptimizationFuel, a, LGraph m l)
+  (DebugNodes m l, Outputable a) =>
+  FPass m l a -> OptimizationFuel -> LGraph m l -> a ->
+  DFM a (OptimizationFuel, a, LGraph m l)
 solve_and_rewrite_f comp fuel graph in_fact =
   do solve_graph_f comp fuel graph in_fact                   -- pass 1
      exit_id    <- freshBlockId "proxy for exit node"
@@ -687,22 +688,23 @@ solve_and_rewrite_f comp fuel graph in_fact =
      return (fuel, exit_fact, g)
 
 forward_rewrite ::
-  forall m l a . (DebugNodes m l, Outputable a) =>
-         FPass m l a -> OptimizationFuel -> G.LGraph m l -> a -> DFM a (OptimizationFuel, G.LGraph m l)
+  (DebugNodes m l, Outputable a) =>
+  FPass m l a -> OptimizationFuel -> G.LGraph m l -> a ->
+  DFM a (OptimizationFuel, G.LGraph m l)
 forward_rewrite comp fuel graph entry_fact =
   do setFact eid entry_fact
      rewrite_blocks fuel emptyBlockEnv (G.postorder_dfs graph) 
   where
     eid = G.gr_entry graph
     is_local id = isJust $ lookupBlockEnv (G.gr_blocks graph) id
-    set_or_save :: LastOutFacts a -> DFM a ()
+    -- set_or_save :: LastOutFacts a -> DFM a ()
     set_or_save (LastOutFacts l) = mapM_ set_or_save_one l
     set_or_save_one (id, a) =
         if is_local id then checkFactMatch id a
         else panic "set fact outside graph during rewriting pass?!"
 
-    rewrite_blocks ::
-      OptimizationFuel -> BlockEnv (Block m l) -> [Block m l] -> DFM a (OptimizationFuel, LGraph m l)
+    -- rewrite_blocks ::
+    --   OptimizationFuel -> BlockEnv (Block m l) -> [Block m l] -> DFM a (OptimizationFuel, LGraph m l)
     rewrite_blocks fuel rewritten [] = return (fuel, G.LGraph eid rewritten)
     rewrite_blocks fuel rewritten (G.Block id t : bs) = 
         do id_fact <- getFact id
@@ -712,8 +714,8 @@ forward_rewrite comp fuel graph entry_fact =
              Rewrite fg -> do { markGraphRewritten
                               ; rewrite_blocks (fuel-1) rewritten
                                 (G.postorder_dfs (labelGraph id fg) ++ bs) }
-    propagate :: OptimizationFuel -> G.ZHead m -> a -> G.ZTail m l -> BlockEnv (G.Block m l) ->
-                 [G.Block m l] -> DFM a (OptimizationFuel, G.LGraph m l)
+    -- propagate :: OptimizationFuel -> G.ZHead m -> a -> G.ZTail m l -> BlockEnv (G.Block m l) ->
+    --             [G.Block m l] -> DFM a (OptimizationFuel, G.LGraph m l)
     propagate fuel h in' (G.ZTail m t) rewritten bs = 
         my_trace "Rewriting middle node" (ppr m) $
         do fc_middle_out comp in' m fuel >>= \x -> case x of