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| author | Simon Marlow <marlowsd@gmail.com> | 2014-07-22 12:04:32 +0100 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2014-07-31 08:55:26 +0100 |
| commit | da70f9ef49a545707dc32db9662441b9c8845fba (patch) | |
| tree | 78947d1a574b1d5d980c120a29cf9e7fc1bf8962 /compiler/nativeGen/RegAlloc/Liveness.hs | |
| parent | 1837b2f38ec3442dcc4e7fd4bc67207fc2064e65 (diff) | |
| download | haskell-da70f9ef49a545707dc32db9662441b9c8845fba.tar.gz | |
Allow multiple entry points when allocating recursive groups (#9303)
Summary:
In this example we ended up with some code that was only reachable via
an info table, because a branch had been optimised away by the native
code generator. The register allocator then got confused because it
was only considering the first block of the proc to be an entry point,
when actually any of the info tables are entry points.
Test Plan: validate
Reviewers: simonpj, austin
Subscribers: simonmar, relrod, carter
Differential Revision: https://phabricator.haskell.org/D88
Diffstat (limited to 'compiler/nativeGen/RegAlloc/Liveness.hs')
| -rw-r--r-- | compiler/nativeGen/RegAlloc/Liveness.hs | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/compiler/nativeGen/RegAlloc/Liveness.hs b/compiler/nativeGen/RegAlloc/Liveness.hs index 1cb6dc8268..d7fd8bdcb4 100644 --- a/compiler/nativeGen/RegAlloc/Liveness.hs +++ b/compiler/nativeGen/RegAlloc/Liveness.hs @@ -169,10 +169,11 @@ data Liveness -- | Stash regs live on entry to each basic block in the info part of the cmm code. data LiveInfo = LiveInfo - (BlockEnv CmmStatics) -- cmm info table static stuff - (Maybe BlockId) -- id of the first block - (Maybe (BlockMap RegSet)) -- argument locals live on entry to this block - (Map BlockId (Set Int)) -- stack slots live on entry to this block + (BlockEnv CmmStatics) -- cmm info table static stuff + [BlockId] -- entry points (first one is the + -- entry point for the proc). + (Maybe (BlockMap RegSet)) -- argument locals live on entry to this block + (Map BlockId (Set Int)) -- stack slots live on entry to this block -- | A basic block with liveness information. @@ -223,9 +224,9 @@ instance Outputable instr | otherwise = name <> (hcat $ punctuate space $ map ppr $ uniqSetToList regs) instance Outputable LiveInfo where - ppr (LiveInfo mb_static firstId liveVRegsOnEntry liveSlotsOnEntry) + ppr (LiveInfo mb_static entryIds liveVRegsOnEntry liveSlotsOnEntry) = (ppr mb_static) - $$ text "# firstId = " <> ppr firstId + $$ text "# entryIds = " <> ppr entryIds $$ text "# liveVRegsOnEntry = " <> ppr liveVRegsOnEntry $$ text "# liveSlotsOnEntry = " <> text (show liveSlotsOnEntry) @@ -480,7 +481,7 @@ stripLive dflags live where stripCmm :: (Outputable statics, Outputable instr, Instruction instr) => LiveCmmDecl statics instr -> NatCmmDecl statics instr stripCmm (CmmData sec ds) = CmmData sec ds - stripCmm (CmmProc (LiveInfo info (Just first_id) _ _) label live sccs) + stripCmm (CmmProc (LiveInfo info (first_id:_) _ _) label live sccs) = let final_blocks = flattenSCCs sccs -- make sure the block that was first in the input list @@ -493,7 +494,7 @@ stripLive dflags live (ListGraph $ map (stripLiveBlock dflags) $ first' : rest') -- procs used for stg_split_markers don't contain any blocks, and have no first_id. - stripCmm (CmmProc (LiveInfo info Nothing _ _) label live []) + stripCmm (CmmProc (LiveInfo info [] _ _) label live []) = CmmProc info label live (ListGraph []) -- If the proc has blocks but we don't know what the first one was, then we're dead. @@ -641,16 +642,19 @@ natCmmTopToLive (CmmData i d) = CmmData i d natCmmTopToLive (CmmProc info lbl live (ListGraph [])) - = CmmProc (LiveInfo info Nothing Nothing Map.empty) lbl live [] + = CmmProc (LiveInfo info [] Nothing Map.empty) lbl live [] natCmmTopToLive proc@(CmmProc info lbl live (ListGraph blocks@(first : _))) = let first_id = blockId first - sccs = sccBlocks blocks (entryBlocks proc) + all_entry_ids = entryBlocks proc + sccs = sccBlocks blocks all_entry_ids + entry_ids = filter (/= first_id) all_entry_ids sccsLive = map (fmap (\(BasicBlock l instrs) -> BasicBlock l (map (\i -> LiveInstr (Instr i) Nothing) instrs))) $ sccs - in CmmProc (LiveInfo info (Just first_id) Nothing Map.empty) lbl live sccsLive + in CmmProc (LiveInfo info (first_id : entry_ids) Nothing Map.empty) + lbl live sccsLive -- |