+{-# OPTIONS -fno-warn-missing-signatures #-}
-- | Graph coloring register allocator.
--
--- TODO:
--- The function that choosing the potential spills could be a bit cleverer.
--- Colors in graphviz graphs could be nicer.
+-- TODO: The colors in graphviz graphs for x86_64 and ppc could be nicer.
--
-{-# OPTIONS -fno-warn-missing-signatures #-}
module RegAllocColor (
regAlloc,
$ 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_coalesced1
+ graph <- {-# SCC "BuildGraph" #-} buildGraph code
-- VERY IMPORTANT:
-- We really do want the graph to be fully evaluated _before_ we start coloring.
-- build a map of the cost of spilling each instruction
-- this will only actually be computed if we have to spill something.
let spillCosts = foldl' plusSpillCostInfo zeroSpillCostInfo
- $ map slurpSpillCostInfo code_coalesced1
+ $ map slurpSpillCostInfo code
-- the function to choose regs to leave uncolored
let spill = chooseSpill spillCosts
= {-# 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_coalesced2
- = map (patchEraseLive patchF) code_coalesced1
+ let code_coalesced
+ = map (patchEraseLive patchF) code
-- see if we've found a coloring
else graph_colored
-- patch the registers using the info in the graph
- let code_patched = map (patchRegsFromGraph graph_colored_lint) code_coalesced2
+ let code_patched = map (patchRegsFromGraph graph_colored_lint) code_coalesced
-- clean out unneeded SPILL/RELOADs
let code_spillclean = map cleanSpills code_patched
-- record what happened in this stage for debugging
let stat =
RegAllocStatsColored
- { raGraph = graph_colored_lint
- , raCoalesced = rmCoalesce
- , raPatched = code_patched
- , raSpillClean = code_spillclean
- , raFinal = code_final
- , raSRMs = foldl' addSRM (0, 0, 0) $ map countSRMs code_spillclean }
+ { raGraph = graph
+ , raGraphColored = graph_colored_lint
+ , raCoalesced = rmCoalesce
+ , raPatched = code_patched
+ , raSpillClean = code_spillclean
+ , raFinal = code_final
+ , raSRMs = foldl' addSRM (0, 0, 0) $ map countSRMs code_spillclean }
let statList =
-- spill the uncolored regs
(code_spilled, slotsFree', spillStats)
- <- regSpill code_coalesced2 slotsFree rsSpill
+ <- regSpill code_coalesced slotsFree rsSpill
-- recalculate liveness
let code_nat = map stripLive code_spilled