diff options
Diffstat (limited to 'compiler/cmm/CmmInfo.hs')
| -rw-r--r-- | compiler/cmm/CmmInfo.hs | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/compiler/cmm/CmmInfo.hs b/compiler/cmm/CmmInfo.hs index b9981f247b..299f7bb271 100644 --- a/compiler/cmm/CmmInfo.hs +++ b/compiler/cmm/CmmInfo.hs @@ -194,7 +194,11 @@ mkInfoTableContents dflags | null liveness_data = rET_SMALL -- Fits in extra_bits | otherwise = rET_BIG -- Does not; extra_bits is -- a label - ; return (prof_data ++ liveness_data, (std_info, srt_label)) } + mb_tiny_liveness = mkTinyLivenessBits frame + ; case (prof_data, liveness_data, srt_label, rts_tag == rET_SMALL, + srt_bitmap == toStgHalfWord dflags 0, mb_tiny_liveness) of + ([], [], [], True, True, Just b) -> return ([], ([b], [])) + _ -> return (prof_data ++ liveness_data, (std_info, srt_label)) } | HeapRep _ ptrs nonptrs closure_type <- smrep = do { let layout = packIntsCLit dflags ptrs nonptrs @@ -317,6 +321,12 @@ makeRelativeRefTo _ _ lit = lit -- The head of the stack layout is the top of the stack and -- the least-significant bit. +mkTinyLivenessBits :: Liveness -> Maybe CmmLit +mkTinyLivenessBits liveness + | length liveness > 7 = Nothing + | otherwise = Just (CmmInt b W8) + where b = foldr (.|.) 0 [ 1 `shiftL` n | (True,n) <- zip (liveness ++ [True]) [0..] ] + mkLivenessBits :: DynFlags -> Liveness -> UniqSM (CmmLit, [RawCmmDecl]) -- ^ Returns: -- 1. The bitmap (literal value or label) |