(c) Update the current assignment
- (d) If the intstruction is a branch:
+ (d) If the instruction is a branch:
if the destination block already has a register assignment,
Generate a new block with fixup code and redirect the
jump to the new block.
import Reg
import BlockId
-import Cmm hiding (RegSet)
+import OldCmm hiding (RegSet)
import Digraph
import Unique
( CmmData sec d
, Nothing )
-regAlloc (CmmProc (LiveInfo info _ _) lbl params (ListGraph []))
- = return ( CmmProc info lbl params (ListGraph [])
+regAlloc (CmmProc (LiveInfo info _ _ _) lbl [])
+ = return ( CmmProc info lbl (ListGraph [])
, Nothing )
-regAlloc (CmmProc static lbl params (ListGraph comps))
- | LiveInfo info (Just first_id) (Just block_live) <- static
+regAlloc (CmmProc static lbl 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
let ((first':_), rest')
= partition ((== first_id) . blockId) final_blocks
- return ( CmmProc info lbl params (ListGraph (first' : rest'))
+ return ( CmmProc info lbl (ListGraph (first' : rest'))
, Just stats)
-- bogus. to make non-exhaustive match warning go away.
-regAlloc (CmmProc _ _ _ _)
+regAlloc (CmmProc _ _ _)
= panic "RegAllocLinear.regAlloc: no match"
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
some reason then this function will loop. We should probably do some
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
+
+ {- BUGS: There are so many unreachable blocks in the code the warnings are overwhelming.
+ pprTrace "RegAlloc.Linear.Main.process: no progress made, bailing out."
+ ( text "Unreachable blocks:"
+ $$ vcat (map ppr next_round)) -}
+ = return $ reverse accum
+
+ | 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
- if isJust (lookupBlockEnv block_assig id)
+ if isJust (mapLookup id block_assig)
|| 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
initBlock :: BlockId -> RegM ()
initBlock id
= do block_assig <- getBlockAssigR
- case lookupBlockEnv block_assig id of
+ case mapLookup id block_assig of
-- no prior info about this block: assume everything is
-- free and the assignment is empty.
Nothing
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
( [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
-- register does not already have an assignment,
-- and the source register is assigned to a register, not to a spill slot,
-- then we can eliminate the instruction.
- -- (we can't eliminitate it if the source register is on the stack, because
+ -- (we can't eliminate it if the source register is on the stack, because
-- we do not want to use one spill slot for different virtual registers)
case takeRegRegMoveInstr instr of
Just (src,dst) | src `elementOfUniqSet` (liveDieRead live),
clobber_saves <- saveClobberedTemps real_written r_dying
-- debugging
-{- freeregs <- getFreeRegsR
+{- freeregs <- getFreeRegsR
assig <- getAssigR
pprTrace "genRaInsn"
(ppr instr
saveClobberedTemps
- :: Instruction instr
+ :: (Outputable instr, Instruction instr)
=> [RealReg] -- real registers clobbered by this instruction
-> [Reg] -- registers which are no longer live after this insn
-> RegM [instr] -- return: instructions to spill any temps that will
--- | Mark all these regal regs as allocated,
+-- | Mark all these real regs as allocated,
-- and kick out their vreg assignments.
--
clobberRegs :: [RealReg] -> RegM ()
-- the list of free registers and free stack slots.
allocateRegsAndSpill
- :: Instruction instr
+ :: (Outputable instr, Instruction instr)
=> Bool -- True <=> reading (load up spilled regs)
-> [VirtualReg] -- don't push these out
-> [instr] -- spill insns
allocateRegsAndSpill reading keep spills (my_reg:alloc) rs
-- case (1b): already in a register (and memory)
- -- NB1. if we're writing this register, update its assignemnt to be
+ -- NB1. if we're writing this register, update its assignment to be
-- InReg, because the memory value is no longer valid.
-- NB2. This is why we must process written registers here, even if they
-- are also read by the same instruction.
-- | Load up a spilled temporary if we need to.
loadTemp
- :: Instruction instr
+ :: (Outputable instr, Instruction instr)
=> Bool
-> VirtualReg -- the temp being loaded
-> Maybe Loc -- the current location of this temp