diff options
Diffstat (limited to 'compiler/nativeGen/BlockLayout.hs')
| -rw-r--r-- | compiler/nativeGen/BlockLayout.hs | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/compiler/nativeGen/BlockLayout.hs b/compiler/nativeGen/BlockLayout.hs index 5e34b28793..7a39071541 100644 --- a/compiler/nativeGen/BlockLayout.hs +++ b/compiler/nativeGen/BlockLayout.hs @@ -638,8 +638,9 @@ dropJumps info ((BasicBlock lbl ins):todo) sequenceTop :: (Instruction instr, Outputable instr) - => DynFlags --Use new layout code - -> NcgImpl statics instr jumpDest -> CFG + => DynFlags -- Determine which layout algo to use + -> NcgImpl statics instr jumpDest + -> Maybe CFG -- ^ CFG if we have one. -> NatCmmDecl statics instr -> NatCmmDecl statics instr sequenceTop _ _ _ top@(CmmData _ _) = top @@ -647,20 +648,17 @@ sequenceTop dflags ncgImpl edgeWeights (CmmProc info lbl live (ListGraph blocks)) | (gopt Opt_CfgBlocklayout dflags) && backendMaintainsCfg dflags --Use chain based algorithm + , Just cfg <- edgeWeights = CmmProc info lbl live ( ListGraph $ ncgMakeFarBranches ncgImpl info $ - sequenceChain info edgeWeights blocks ) + sequenceChain info cfg blocks ) | otherwise --Use old algorithm - = CmmProc info lbl live ( ListGraph $ ncgMakeFarBranches ncgImpl info $ - sequenceBlocks cfg info blocks) + = let cfg = if dontUseCfg then Nothing else edgeWeights + in CmmProc info lbl live ( ListGraph $ ncgMakeFarBranches ncgImpl info $ + sequenceBlocks cfg info blocks) where - cfg - | (gopt Opt_WeightlessBlocklayout dflags) || - (not $ backendMaintainsCfg dflags) - -- Don't make use of cfg in the old algorithm - = Nothing - -- Use cfg in the old algorithm - | otherwise = Just edgeWeights + dontUseCfg = gopt Opt_WeightlessBlocklayout dflags || + (not $ backendMaintainsCfg dflags) -- The old algorithm: -- It is very simple (and stupid): We make a graph out of |