Merge in new code generator branch.

This changes the new code generator to make use of the Hoopl package
for dataflow analysis.  Hoopl is a new boot package, and is maintained
in a separate upstream git repository (as usual, GHC has its own
lagging darcs mirror in http://darcs.haskell.org/packages/hoopl).

During this merge I squashed recent history into one patch.  I tried
to rebase, but the history had some internal conflicts of its own
which made rebase extremely confusing, so I gave up. The history I
squashed was:

  - Update new codegen to work with latest Hoopl
  - Add some notes on new code gen to cmm-notes
  - Enable Hoopl lag package.
  - Add SPJ note to cmm-notes
  - Improve GC calls on new code generator.

Work in this branch was done by:
   - Milan Straka <fox@ucw.cz>
   - John Dias <dias@cs.tufts.edu>
   - David Terei <davidterei@gmail.com>

Edward Z. Yang <ezyang@mit.edu> merged in further changes from GHC HEAD
and fixed a few bugs.

1 files changed, 0 insertions, 88 deletions

diff --git a/compiler/cmm/PprCmmZ.hs b/compiler/cmm/PprCmmZ.hs
deleted file mode 100644
index 075f0e457b..0000000000
--- a/compiler/cmm/PprCmmZ.hs
+++ /dev/null
@@ -1,88 +0,0 @@
-
-module PprCmmZ
-    ( pprCmmGraphLikeCmm
-    )
-where
-
-import BlockId
-import Cmm
-import PprCmm
-import Outputable
-import qualified ZipCfgCmmRep as G
-import qualified ZipCfg as Z
-import CmmZipUtil
-
-import Data.Maybe
-import FastString
-
-----------------------------------------------------------------
--- | The purpose of this function is to print a Cmm zipper graph "as if it were"
--- a Cmm program.  The objective is dodgy, so it's unsurprising parts of the
--- code are dodgy as well.
-
-pprCmmGraphLikeCmm :: G.CmmGraph -> SDoc
-pprCmmGraphLikeCmm g = vcat (swallow blocks)
-    where blocks = Z.postorder_dfs g
-          swallow :: [G.CmmBlock] -> [SDoc]
-          swallow [] = []
-          swallow (Z.Block id t : rest) = tail id [] Nothing t rest
-          tail id prev' out (Z.ZTail m t) rest = tail id (mid m : prev') out t rest
-          tail id prev' out (Z.ZLast (Z.LastOther l)) rest = last id prev' out l rest
-          tail id prev' _   (Z.ZLast Z.LastExit)      rest = exit id prev' rest
-          mid m = ppr m
-          block' id prev'
-              | id == Z.lg_entry g, entry_has_no_pred =
-                            vcat (text "<entry>" : reverse prev')
-              | otherwise = hang (ppr id <> colon) 4 (vcat (reverse prev'))
-          last id prev' out l n =
-              let endblock stmt = block' id (stmt : prev') : swallow n in
-              case l of
-                G.LastBranch tgt ->
-                    case n of
-                      Z.Block id' t : bs
-                          | tgt == id', unique_pred id' 
-                          -> tail id prev' out t bs  -- optimize out redundant labels
-                      _ -> endblock (ppr $ CmmBranch tgt)
-                l@(G.LastCondBranch expr tid fid) ->
-                  let ft id = text "// fall through to " <> ppr id in
-                  case n of
-                    Z.Block id' t : bs
-                      | id' == fid, isNothing out ->
-                          tail id (ft fid : ppr (CmmCondBranch expr tid) : prev') Nothing t bs
-                      | id' == tid, Just e' <- maybeInvertCmmExpr expr, isNothing out->
-                          tail id (ft tid : ppr (CmmCondBranch e'   fid) : prev') Nothing t bs
-                    _ -> endblock $ with_out out l
-                l@(G.LastSwitch {})      -> endblock $ with_out out l
-                l@(G.LastCall _ _ _ _ _) -> endblock $ with_out out l
-          exit id prev' n = -- highly irregular (assertion violation?)
-              let endblock stmt = block' id (stmt : prev') : swallow n in
-              endblock (text "// <exit>")
-          preds = zipPreds g
-          entry_has_no_pred = case lookupBlockEnv preds (Z.lg_entry g) of
-                                Nothing -> True
-                                Just s -> isEmptyBlockSet s
-          single_preds =
-              let add b single =
-                    let id = Z.blockId b
-                    in  case lookupBlockEnv preds id of
-                          Nothing -> single
-                          Just s -> if sizeBlockSet s == 1 then
-                                        extendBlockSet single id
-                                    else single
-              in  Z.fold_blocks add emptyBlockSet g
-          unique_pred id = elemBlockSet id single_preds
-
-with_out :: Maybe (G.Convention, CmmActuals) -> G.Last -> SDoc
-with_out Nothing l = ptext (sLit "??no-arguments??") <+> ppr l
-with_out (Just (conv, args)) l = last l
-    where last (G.LastCall e k _ _ _) =
-              hcat [ptext (sLit "... = foreign "),
-                    doubleQuotes(ppr conv), space,
-                    ppr_target e, parens ( commafy $ map ppr args ),
-                    ptext (sLit " \"safe\""),
-                    text " returns to " <+> ppr k,
-                    semi ]
-          last l = ppr l
-          ppr_target (CmmLit lit) = pprLit lit
-          ppr_target fn'          = parens (ppr fn')
-          commafy xs = hsep $ punctuate comma xs