NCG: Refactor representation of code with liveness info

[ghc-hetmet.git] / compiler / nativeGen / RegAlloc / Linear / Main.hs

diff --git a/compiler/nativeGen/RegAlloc/Linear/Main.hs b/compiler/nativeGen/RegAlloc/Linear/Main.hs
index 7201207..29cc0e5 100644 (file)
--- a/compiler/nativeGen/RegAlloc/Linear/Main.hs
+++ b/compiler/nativeGen/RegAlloc/Linear/Main.hs
@@ -132,20 +132,16 @@ regAlloc (CmmData sec d)
                ( CmmData sec d
                , Nothing )
        
-regAlloc (CmmProc (LiveInfo info _ _) lbl params (ListGraph []))
+regAlloc (CmmProc (LiveInfo info _ _) lbl params [])
        = return ( CmmProc info lbl params (ListGraph [])
                 , Nothing )
        
-regAlloc (CmmProc static lbl params (ListGraph comps))
-       | LiveInfo info (Just first_id) block_live      <- static
+regAlloc (CmmProc static lbl params sccs)
+       | LiveInfo info (Just first_id) (Just block_live)       <- static
        = do    
                -- do register allocation on each component.
                (final_blocks, stats)
-                       <- linearRegAlloc first_id block_live 
-                       $ map (\b -> case b of 
-                                       BasicBlock _ [b]        -> AcyclicSCC b
-                                       BasicBlock _ bs         -> CyclicSCC  bs)
-                       $ comps
+                       <- linearRegAlloc first_id block_live sccs
 
                -- make sure the block that was first in the input list
                --      stays at the front of the output
@@ -194,7 +190,7 @@ linearRA_SCCs first_id block_live blocksAcc (AcyclicSCC block : sccs)
 
 linearRA_SCCs first_id block_live blocksAcc (CyclicSCC blocks : sccs) 
  = do
-        blockss' <- process first_id block_live blocks [] (return [])
+        blockss' <- process first_id block_live blocks [] (return []) False
        linearRA_SCCs first_id block_live
                (reverse (concat blockss') ++ blocksAcc)
                sccs
@@ -211,13 +207,21 @@ linearRA_SCCs first_id block_live blocksAcc (CyclicSCC blocks : sccs)
    more sanity checking to guard against this eventuality.
 -}
                
-process _ _ [] []         accum 
+process _ _ [] []         accum _
        = return $ reverse accum
 
-process first_id block_live [] next_round accum 
-       = process first_id block_live next_round [] accum
+process first_id block_live [] next_round accum madeProgress
+       | not madeProgress
+       = pprPanic "RegAlloc.Linear.Main.process: no progress made, bailing out" 
+               (  text "stalled blocks:"
+               $$ vcat (map ppr next_round))
+       
+       | otherwise
+       = process first_id block_live 
+                 next_round [] accum False
 
-process first_id block_live (b@(BasicBlock id _) : blocks) next_round accum 
+process first_id block_live (b@(BasicBlock id _) : blocks) 
+       next_round accum madeProgress
  = do  
        block_assig <- getBlockAssigR
 
@@ -225,9 +229,11 @@ process first_id block_live (b@(BasicBlock id _) : blocks) next_round accum
              || id == first_id
          then do 
                b'  <- processBlock block_live b
-                process first_id block_live blocks next_round (b' : accum)
+                process first_id block_live blocks 
+                       next_round (b' : accum) True
 
-         else  process first_id block_live blocks (b : next_round) accum
+         else  process first_id block_live blocks 
+                       (b : next_round) accum madeProgress
 
 
 -- | Do register allocation on this basic block
@@ -286,7 +292,7 @@ linearRA _          accInstr accFixup _ []
 
 linearRA block_live accInstr accFixups id (instr:instrs)
  = do
-       (accInstr', new_fixups) 
+       (accInstr', new_fixups) 
                <- raInsn block_live accInstr id instr
 
        linearRA block_live accInstr' (new_fixups ++ accFixups) id instrs
@@ -303,17 +309,17 @@ raInsn
                ( [instr]                       -- new instructions
                , [NatBasicBlock instr])        -- extra fixup blocks
 
-raInsn _     new_instrs _ (Instr ii Nothing)  
+raInsn _     new_instrs _ (LiveInstr ii Nothing)  
        | Just n        <- takeDeltaInstr ii
        = do    setDeltaR n
                return (new_instrs, [])
 
-raInsn _     new_instrs _ (Instr ii Nothing)
+raInsn _     new_instrs _ (LiveInstr ii Nothing)
        | isMetaInstr ii
        = return (new_instrs, [])
 
 
-raInsn block_live new_instrs id (Instr instr (Just live))
+raInsn block_live new_instrs id (LiveInstr (Instr instr) (Just live))
  = do
     assig    <- getAssigR
 
@@ -374,9 +380,9 @@ genRaInsn block_live new_instrs block_id instr r_dying w_dying =
     clobber_saves      <- saveClobberedTemps real_written r_dying
 
     -- debugging
-{-  freeregs <- getFreeRegsR
+    freeregs <- getFreeRegsR
     assig    <- getAssigR
-    pprTrace "genRaInsn" 
+{-    pprTrace "genRaInsn" 
        (ppr instr 
                $$ text "r_dying      = " <+> ppr r_dying 
                $$ text "w_dying      = " <+> ppr w_dying