Cmm back end upgrades

[ghc-hetmet.git] / compiler / cmm / MkZipCfg.hs

diff --git a/compiler/cmm/MkZipCfg.hs b/compiler/cmm/MkZipCfg.hs
index 8b0284c..73f7b5a 100644 (file)
--- a/compiler/cmm/MkZipCfg.hs
+++ b/compiler/cmm/MkZipCfg.hs
@@ -1,6 +1,7 @@
-{-# OPTIONS -Wall -fno-warn-name-shadowing #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 module MkZipCfg
-    ( AGraph, (<*>), emptyAGraph, withFreshLabel, withUnique
+    ( AGraph, (<*>), catAGraphs
+    , emptyAGraph, withFreshLabel, withUnique
     , mkMiddle, mkMiddles, mkLast, mkZTail, mkBranch, mkLabel, mkIfThenElse, mkWhileDo
     , outOfLine
     , emptyGraph, graphOfMiddles, graphOfZTail
@@ -8,15 +9,18 @@ module MkZipCfg
     )
 where
 
+import StackSlot
 import ZipCfg
 
 import Outputable
 import Unique
 import UniqFM
 import UniqSupply
+import Util
 
 import Prelude hiding (zip, unzip, last)
 
+#include "HsVersions.h"
 
 -------------------------------------------------------------------------
 --     GENERIC ZIPPER-BASED CONTROL-FLOW GRAPH (CONSTRUCTOR VIEW)      --
@@ -152,6 +156,8 @@ representation is agnostic on this point.)
 infixr 3 <*>
 (<*>) :: AGraph m l -> AGraph m l -> AGraph m l
 
+catAGraphs :: [AGraph m l] -> AGraph m l
+
 -- | A graph is built up by splicing together graphs each containing a
 -- single node (where a label is considered a 'first' node.  The empty
 -- graph is a left and right unit for splicing.  All of the AGraph
@@ -159,9 +165,9 @@ infixr 3 <*>
 -- splicing operation <*>, are constant-time operations.
 
 emptyAGraph :: AGraph m l
-mkLabel     :: LastNode l =>
+mkLabel     :: (LastNode l) =>
                BlockId -> AGraph m l              -- graph contains the label
-mkMiddle    :: m       -> AGraph m l              -- graph contains the node
+mkMiddle    :: m -> AGraph m l   -- graph contains the node
 mkLast      :: (Outputable m, Outputable l, LastNode l) =>
                l       -> AGraph m l              -- graph contains the node
 
@@ -190,13 +196,22 @@ outOfLine :: (LastNode l, Outputable m, Outputable l)
 
 
 -- below for convenience
-mkMiddles ::                                             [m]       -> AGraph m l
-mkZTail   :: (Outputable m, Outputable l, LastNode l) => ZTail m l -> AGraph m l
-mkBranch  :: (Outputable m, Outputable l, LastNode l) => BlockId   -> AGraph m l
+mkMiddles :: [m] -> AGraph m l
+mkZTail   :: (Outputable m, Outputable l, LastNode l) =>
+  ZTail m l -> AGraph m l
+mkBranch  :: (Outputable m, Outputable l, LastNode l) =>
+  BlockId   -> AGraph m l
 
 -- | For the structured control-flow constructs, a condition is
 -- represented as a function that takes as arguments the labels to
 -- goto on truth or falsehood.
+--
+--     mkIfThenElse mk_cond then else
+--     = (mk_cond L1 L2) <*> L1: then <*> goto J
+--                       <*> L2: else <*> goto J
+--       <*> J:
+--
+-- where L1, L2, J are fresh
 
 mkIfThenElse :: (Outputable m, Outputable l, LastNode l)
                 => (BlockId -> BlockId -> AGraph m l) -- branch condition
@@ -214,8 +229,8 @@ mkWhileDo    :: (Outputable m, Outputable l, LastNode l)
 -- in the number of basic blocks.  The conversion is also monadic
 -- because it may require the allocation of fresh, unique labels.
 
-graphOfAGraph  ::            AGraph m l -> UniqSM (Graph  m l)
-lgraphOfAGraph ::            AGraph m l -> UniqSM (LGraph m l)
+graphOfAGraph  :: AGraph m l -> UniqSM (Graph  m l)
+lgraphOfAGraph :: AGraph m l -> UniqSM (LGraph m l)
   -- ^ allocate a fresh label for the entry point
 labelAGraph    :: BlockId -> AGraph m l -> UniqSM (LGraph m l)
   -- ^ use the given BlockId as the label of the entry point
@@ -239,6 +254,8 @@ newtype AGraph m l = AGraph (Graph m l -> UniqSM (Graph m l))
 AGraph f1 <*> AGraph f2 = AGraph f 
     where f g = f2 g >>= f1 -- note right associativity
 
+catAGraphs = foldr (<*>) emptyAGraph
+
 emptyAGraph = AGraph return
 
 graphOfAGraph (AGraph f) = f emptyGraph
@@ -287,7 +304,7 @@ withFreshLabel name ofId = AGraph f
                  f' g
 
 withUnique ofU = AGraph f
-  where f g = do u <- getUniqueUs
+  where f g = do u <- getUniqueM
                  let AGraph f' = ofU u
                  f' g
 
@@ -320,15 +337,11 @@ mkWhileDo cbranch body =
 note_this_code_becomes_unreachable ::
     (Monad m, LastNode l, Outputable middle, Outputable l) => ZTail middle l -> m ()
 
-#ifdef DEBUG
-note_this_code_becomes_unreachable = u
+note_this_code_becomes_unreachable = if debugIsOn then u else \_ -> return ()
     where u (ZLast LastExit)                       = return ()
           u (ZLast (LastOther l)) | isBranchNode l = return ()
                                     -- Note [Branch follows branch]
           u tail = fail ("unreachable code: " ++ showSDoc (ppr tail))
-#else
-note_this_code_becomes_unreachable _ = return ()
-#endif
 
 {-
 Note [Branch follows branch]
@@ -340,3 +353,13 @@ giving it a label, and start a new one that branches to that label.
 Emitting a Branch at this point is fine: 
        goto L1; L2: ...stuff... 
 -}
+
+
+-- | The string argument to 'freshBlockId' was originally helpful in debugging
+-- the Quick C-- compiler, so I have kept it here even though at present it is
+-- thrown away at this spot---there's no reason a BlockId couldn't one day carry
+-- a string.  
+
+freshBlockId :: String -> UniqSM BlockId
+freshBlockId _ = do { u <- getUniqueM; return $ BlockId u }
+