[PATCH] Add CmmGraphPoly, which is a polymorphic version of CmmGraph.

[Edward Z. Yang]

I figure this might be slightly controversial, so I'd like to run it
by you guys.  Suggestions for: type renamings, constructor renamings, etc?
We need a polymorphic CmmGraph to deal with decorated nodes, as discussed
with Hoopl.

Edward

Excerpts from Edward Z. Yang's message of Wed Apr 13 06:23:32 -0400 2011:
> Signed-off-by: Edward Z. Yang <ezyang at mit.edu>
> ---
>  compiler/cmm/Cmm.hs |   21 +++++++++++++--------
>  1 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/compiler/cmm/Cmm.hs b/compiler/cmm/Cmm.hs
> index 2e9f952..0749ca1 100644
> --- a/compiler/cmm/Cmm.hs
> +++ b/compiler/cmm/Cmm.hs
> @@ -9,10 +9,11 @@
>  #endif
>  
>  module Cmm
> -  ( CmmGraph(..), CmmBlock
> +  ( CmmGraph, CmmGraphPoly(..), CmmBlock
>    , CmmStackInfo(..), CmmTopInfo(..), Cmm, CmmTop
>    , CmmReplGraph, CmmFwdRewrite, CmmBwdRewrite
>  
> +  , modifyGraph
>    , lastNode, replaceLastNode, insertBetween
>    , ofBlockMap, toBlockMap, insertBlock
>    , ofBlockList, toBlockList, bodyToBlockList
> @@ -41,7 +42,8 @@ import Panic
>  -------------------------------------------------
>  -- CmmBlock, CmmGraph and Cmm
>  
> -data CmmGraph = CmmGraph { g_entry :: BlockId, g_graph :: Graph CmmNode C C }
> +type CmmGraph = CmmGraphPoly CmmNode
> +data CmmGraphPoly n = CmmGraph { g_entry :: BlockId, g_graph :: Graph n C C }
>  type CmmBlock = Block CmmNode C C
>  
>  type CmmReplGraph e x = FuelUniqSM (Maybe (Graph CmmNode e x))
> @@ -56,6 +58,9 @@ type CmmTop       = GenCmmTop CmmStatic CmmTopInfo CmmGraph
>  -------------------------------------------------
>  -- Manipulating CmmGraphs
>  
> +modifyGraph :: (Graph n C C -> Graph n' C C) -> CmmGraphPoly n -> CmmGraphPoly n'
> +modifyGraph f g = CmmGraph {g_entry=g_entry g, g_graph=f (g_graph g)}
> +
>  toBlockMap :: CmmGraph -> LabelMap CmmBlock
>  toBlockMap (CmmGraph {g_graph=GMany NothingO body NothingO}) = body
>  
> @@ -150,26 +155,26 @@ insertBetween b ms succId = insert $ lastNode b
>  -- Running dataflow analysis and/or rewrites
>  
>  -- Constructing forward and backward analysis-only pass
> -analFwd    :: Monad m => DataflowLattice f -> FwdTransfer CmmNode f -> FwdPass m CmmNode f
> -analBwd    :: Monad m => DataflowLattice f -> BwdTransfer CmmNode f -> BwdPass m CmmNode f
> +analFwd    :: Monad m => DataflowLattice f -> FwdTransfer n f -> FwdPass m n f
> +analBwd    :: Monad m => DataflowLattice f -> BwdTransfer n f -> BwdPass m n f
>  
>  analFwd lat xfer = analRewFwd lat xfer noFwdRewrite
>  analBwd lat xfer = analRewBwd lat xfer noBwdRewrite
>  
>  -- Constructing forward and backward analysis + rewrite pass
> -analRewFwd :: Monad m => DataflowLattice f -> FwdTransfer CmmNode f -> FwdRewrite m CmmNode f -> FwdPass m CmmNode f
> -analRewBwd :: Monad m => DataflowLattice f -> BwdTransfer CmmNode f -> BwdRewrite m CmmNode f -> BwdPass m CmmNode f
> +analRewFwd :: Monad m => DataflowLattice f -> FwdTransfer n f -> FwdRewrite m n f -> FwdPass m n f
> +analRewBwd :: Monad m => DataflowLattice f -> BwdTransfer n f -> BwdRewrite m n f -> BwdPass m n f
>  
>  analRewFwd lat xfer rew = FwdPass {fp_lattice = lat, fp_transfer = xfer, fp_rewrite = rew}
>  analRewBwd lat xfer rew = BwdPass {bp_lattice = lat, bp_transfer = xfer, bp_rewrite = rew}
>  
>  -- Running forward and backward dataflow analysis + optional rewrite
> -dataflowPassFwd :: CmmGraph -> [(BlockId, f)] -> FwdPass FuelUniqSM CmmNode f -> FuelUniqSM (CmmGraph, BlockEnv f)
> +dataflowPassFwd :: NonLocal n => CmmGraphPoly n -> [(BlockId, f)] -> FwdPass FuelUniqSM n f -> FuelUniqSM (CmmGraphPoly n, BlockEnv f)
>  dataflowPassFwd (CmmGraph {g_entry=entry, g_graph=graph}) facts fwd = do
>    (graph, facts, NothingO) <- analyzeAndRewriteFwd fwd (JustC [entry]) graph (mkFactBase (fp_lattice fwd) facts)
>    return (CmmGraph {g_entry=entry, g_graph=graph}, facts)
>  
> -dataflowPassBwd :: CmmGraph -> [(BlockId, f)] -> BwdPass FuelUniqSM CmmNode f -> FuelUniqSM (CmmGraph, BlockEnv f)
> +dataflowPassBwd :: NonLocal n => CmmGraphPoly n -> [(BlockId, f)] -> BwdPass FuelUniqSM n f -> FuelUniqSM (CmmGraphPoly n, BlockEnv f)
>  dataflowPassBwd (CmmGraph {g_entry=entry, g_graph=graph}) facts bwd = do
>    (graph, facts, NothingO) <- analyzeAndRewriteBwd bwd (JustC [entry]) graph (mkFactBase (bp_lattice bwd) facts)
>    return (CmmGraph {g_entry=entry, g_graph=graph}, facts)