import RegSpill
import RegSpillClean
import RegAllocStats
+-- import RegCoalesce
import MachRegs
import MachInstrs
import PprMach
, dopt Opt_D_dump_asm_stats dflags
, dopt Opt_D_dump_asm_conflicts dflags ]
-
-- check that we're not running off down the garden path.
when (spinCount > maxSpinCount)
$ pprPanic "regAlloc_spin: max build/spill cycle count exceeded."
$ uniqSetToList $ unionManyUniqSets $ eltsUFM regsFree)
$$ text "slotsFree = " <> ppr (sizeUniqSet slotsFree))
+
+ -- Brig's algorithm does reckless coalescing for all but the first allocation stage
+ -- Doing this seems to reduce the number of reg-reg moves, but at the cost-
+ -- of creating more spills. Probably better just to stick with conservative
+ -- coalescing in Color.colorGraph for now.
+ --
+ {- code_coalesced1 <- if (spinCount > 0)
+ then regCoalesce code
+ else return code -}
+
+ let code_coalesced1 = code
+
+
-- build a conflict graph from the code.
- graph <- {-# SCC "BuildGraph" #-} buildGraph code
+ graph <- {-# SCC "BuildGraph" #-} buildGraph code_coalesced1
-- VERY IMPORTANT:
-- We really do want the graph to be fully evaluated _before_ we start coloring.
-- this is lazy, it won't be computed unless we need to spill
let fmLife = {-# SCC "LifetimeCount" #-} plusUFMs_C (\(r1, l1) (_, l2) -> (r1, l1 + l2))
- $ map lifetimeCount code
+ $ map lifetimeCount code_coalesced1
-- record startup state
let stat1 =
= {-# SCC "ColorGraph" #-}
Color.colorGraph
(dopt Opt_RegsIterative dflags)
+ spinCount
regsFree triv spill graph
-- rewrite regs in the code that have been coalesced
let patchF reg = case lookupUFM rmCoalesce reg of
Just reg' -> patchF reg'
Nothing -> reg
- let code_coalesced
- = map (patchEraseLive patchF) code
+ let code_coalesced2
+ = map (patchEraseLive patchF) code_coalesced1
-- see if we've found a coloring
if isEmptyUniqSet rsSpill
then do
-- patch the registers using the info in the graph
- let code_patched = map (patchRegsFromGraph graph_colored) code_coalesced
+ let code_patched = map (patchRegsFromGraph graph_colored) code_coalesced2
-- clean out unneeded SPILL/RELOADs
let code_spillclean = map cleanSpills code_patched
else do
-- spill the uncolored regs
(code_spilled, slotsFree', spillStats)
- <- regSpill code_coalesced slotsFree rsSpill
+ <- regSpill code_coalesced2 slotsFree rsSpill
-- recalculate liveness
let code_nat = map stripLive code_spilled
let moveBag = unionBags (unionManyBags moveList2) (unionManyBags moveList)
let graph_coalesce = foldrBag graphAddCoalesce graph_conflict moveBag
- return $ Color.validateGraph (text "urk") graph_coalesce
+ return graph_coalesce
-- | Add some conflict edges to the graph.