where
-import Cmm
-import Regs
-import RegLiveness
-import RegAllocInfo
+import RegAlloc.Liveness
+import Instruction
+import Reg
+import OldCmm
import Bag
+import Digraph
import UniqFM
import UniqSet
import UniqSupply
-import Control.Monad
import Data.List
-- | Do register coalescing on this top level thing
-- For Reg -> Reg moves, if the first reg dies at the same time the second reg is born
-- then the mov only serves to join live ranges. The two regs can be renamed to be
-- the same and the move instruction safely erased.
+regCoalesce
+ :: Instruction instr
+ => [LiveCmmTop instr]
+ -> UniqSM [LiveCmmTop instr]
-regCoalesce :: [LiveCmmTop] -> UniqSM [LiveCmmTop]
regCoalesce code
= do
let joins = foldl' unionBags emptyBag
-- | Slurp out mov instructions that only serve to join live ranges.
-- During a mov, if the source reg dies and the destiation reg is born
-- then we can rename the two regs to the same thing and eliminate the move.
---
-slurpJoinMovs :: LiveCmmTop -> Bag (Reg, Reg)
+slurpJoinMovs
+ :: Instruction instr
+ => LiveCmmTop instr
+ -> Bag (Reg, Reg)
+
slurpJoinMovs live
= slurpCmm emptyBag live
where
- slurpCmm rs CmmData{} = rs
- slurpCmm rs (CmmProc _ _ _ (ListGraph blocks)) = foldl' slurpComp rs blocks
- slurpComp rs (BasicBlock _ blocks) = foldl' slurpBlock rs blocks
- slurpBlock rs (BasicBlock _ instrs) = foldl' slurpLI rs instrs
+ slurpCmm rs CmmData{} = rs
+ slurpCmm rs (CmmProc _ _ sccs) = foldl' slurpBlock rs (flattenSCCs sccs)
+ slurpBlock rs (BasicBlock _ instrs) = foldl' slurpLI rs instrs
- slurpLI rs (Instr _ Nothing) = rs
- slurpLI rs (Instr instr (Just live))
- | Just (r1, r2) <- isRegRegMove instr
+ slurpLI rs (LiveInstr _ Nothing) = rs
+ slurpLI rs (LiveInstr instr (Just live))
+ | Just (r1, r2) <- takeRegRegMoveInstr instr
, elementOfUniqSet r1 $ liveDieRead live
, elementOfUniqSet r2 $ liveBorn live
| otherwise
= rs
-
+