2 -- The above warning supression flag is a temporary kludge.
3 -- While working on this module you are encouraged to remove it and fix
4 -- any warnings in the module. See
5 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
13 #include "HsVersions.h"
36 cmmToRawCmm :: [Cmm] -> IO [RawCmm]
38 info_tbl_uniques <- mkSplitUniqSupply 'i'
39 return $ zipWith raw_cmm (listSplitUniqSupply info_tbl_uniques) cmm
41 raw_cmm uniq_supply (Cmm procs) =
42 Cmm $ concat $ zipWith mkInfoTable (uniqsFromSupply uniq_supply) procs
44 -- Make a concrete info table, represented as a list of CmmStatic
45 -- (it can't be simply a list of Word, because the SRT field is
46 -- represented by a label+offset expression).
48 -- With tablesNextToCode, the layout is
49 -- <reversed variable part>
50 -- <normal forward StgInfoTable, but without
51 -- an entry point at the front>
54 -- Without tablesNextToCode, the layout of an info table is
56 -- <normal forward rest of StgInfoTable>
57 -- <forward variable part>
59 -- See includes/InfoTables.h
61 -- For return-points these are as follows
63 -- Tables next to code:
66 -- <standard info table>
67 -- ret-addr --> <entry code (if any)>
69 -- Not tables-next-to-code:
71 -- ret-addr --> <ptr to entry code>
72 -- <standard info table>
75 -- * The SRT slot is only there if there is SRT info to record
77 mkInfoTable :: Unique -> CmmTop -> [RawCmmTop]
78 mkInfoTable uniq (CmmData sec dat) = [CmmData sec dat]
79 mkInfoTable uniq (CmmProc (CmmInfo _ _ info) entry_label arguments blocks) =
81 -- | Code without an info table. Easy.
82 CmmNonInfoTable -> [CmmProc [] entry_label arguments blocks]
84 CmmInfoTable (ProfilingInfo ty_prof cl_prof) type_tag type_info ->
85 let info_label = entryLblToInfoLbl entry_label
86 ty_prof' = makeRelativeRefTo info_label ty_prof
87 cl_prof' = makeRelativeRefTo info_label cl_prof
89 -- | A function entry point.
90 FunInfo (ptrs, nptrs) srt fun_type fun_arity pap_bitmap slow_entry ->
91 mkInfoTableAndCode info_label std_info fun_extra_bits entry_label
95 [packHalfWordsCLit fun_type fun_arity] ++
98 (if null srt_label then [mkIntCLit 0] else srt_label) ++
99 [makeRelativeRefTo info_label $ mkLivenessCLit liveness,
100 makeRelativeRefTo info_label slow_entry]
102 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag srt_bitmap
104 (srt_label, srt_bitmap) = mkSRTLit info_label srt
105 layout = packHalfWordsCLit ptrs nptrs
108 ConstrInfo (ptrs, nptrs) con_tag descr ->
109 mkInfoTableAndCode info_label std_info [con_name] entry_label
112 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag con_tag layout
113 con_name = makeRelativeRefTo info_label descr
114 layout = packHalfWordsCLit ptrs nptrs
117 ThunkInfo (ptrs, nptrs) srt ->
118 mkInfoTableAndCode info_label std_info srt_label entry_label
121 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag srt_bitmap layout
122 (srt_label, srt_bitmap) = mkSRTLit info_label srt
123 layout = packHalfWordsCLit ptrs nptrs
125 -- | A selector thunk.
126 ThunkSelectorInfo offset srt ->
127 mkInfoTableAndCode info_label std_info [{- no SRT -}] entry_label
130 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag 0 (mkWordCLit offset)
132 -- A continuation/return-point.
133 ContInfo stack_layout srt ->
135 mkInfoTableAndCode info_label std_info srt_label entry_label
138 std_info = mkStdInfoTable ty_prof' cl_prof' maybe_big_type_tag srt_bitmap
139 (makeRelativeRefTo info_label liveness_lit)
140 (liveness_lit, liveness_data, liveness_tag) =
141 mkLiveness uniq stack_layout
142 maybe_big_type_tag = if type_tag == rET_SMALL
145 (srt_label, srt_bitmap) = mkSRTLit info_label srt
147 -- Handle the differences between tables-next-to-code
148 -- and not tables-next-to-code
149 mkInfoTableAndCode :: CLabel
153 -> CmmFormalsWithoutKinds
156 mkInfoTableAndCode info_lbl std_info extra_bits entry_lbl args blocks
157 | tablesNextToCode -- Reverse the extra_bits; and emit the top-level proc
158 = [CmmProc (map CmmStaticLit (reverse extra_bits ++ std_info))
159 entry_lbl args blocks]
161 | ListGraph [] <- blocks -- No code; only the info table is significant
162 = -- Use a zero place-holder in place of the
163 -- entry-label in the info table
164 [mkRODataLits info_lbl (zeroCLit : std_info ++ extra_bits)]
166 | otherwise -- Separately emit info table (with the function entry
167 = -- point as first entry) and the entry code
168 [CmmProc [] entry_lbl args blocks,
169 mkDataLits info_lbl (CmmLabel entry_lbl : std_info ++ extra_bits)]
173 -> ([CmmLit], -- srt_label
174 StgHalfWord) -- srt_bitmap
175 mkSRTLit info_label NoC_SRT = ([], 0)
176 mkSRTLit info_label (C_SRT lbl off bitmap) =
177 ([makeRelativeRefTo info_label (cmmLabelOffW lbl off)], bitmap)
179 -------------------------------------------------------------------------
181 -- Build a liveness mask for the stack layout
183 -------------------------------------------------------------------------
185 -- There are four kinds of things on the stack:
187 -- - pointer variables (bound in the environment)
188 -- - non-pointer variables (bound in the environment)
189 -- - free slots (recorded in the stack free list)
190 -- - non-pointer data slots (recorded in the stack free list)
192 -- The first two are represented with a 'Just' of a 'LocalReg'.
193 -- The last two with one or more 'Nothing' constructors.
194 -- Each 'Nothing' represents one used word.
196 -- The head of the stack layout is the top of the stack and
197 -- the least-significant bit.
199 -- TODO: refactor to use utility functions
200 -- TODO: combine with CgCallConv.mkLiveness (see comment there)
203 -> (CmmLit, -- ^ The bitmap (literal value or label)
204 [RawCmmTop], -- ^ Large bitmap CmmData if needed
205 ClosureTypeTag) -- ^ rET_SMALL or rET_BIG
206 mkLiveness uniq live =
207 if length bits > mAX_SMALL_BITMAP_SIZE
208 -- does not fit in one word
209 then (CmmLabel big_liveness, [data_lits], rET_BIG)
211 else (mkWordCLit small_liveness, [], rET_SMALL)
214 mkBits (reg:regs) = take sizeW bits ++ mkBits regs where
217 Just r -> (machRepByteWidth (localRegRep r) + wORD_SIZE - 1)
219 -- number of words, rounded up
220 bits = repeat $ is_non_ptr reg -- True <=> Non Ptr
222 is_non_ptr Nothing = True
223 is_non_ptr (Just reg) =
224 case localRegGCFollow reg of
232 bitmap = mkBitmap bits
234 small_bitmap = case bitmap of
236 [b] -> fromIntegral b
237 _ -> panic "mkLiveness"
239 fromIntegral (length bits) .|. (small_bitmap `shiftL` bITMAP_BITS_SHIFT)
241 big_liveness = mkBitmapLabel uniq
242 lits = mkWordCLit (fromIntegral (length bits)) : map mkWordCLit bitmap
243 data_lits = mkRODataLits big_liveness lits
245 -------------------------------------------------------------------------
247 -- Generating a standard info table
249 -------------------------------------------------------------------------
251 -- The standard bits of an info table. This part of the info table
252 -- corresponds to the StgInfoTable type defined in InfoTables.h.
254 -- Its shape varies with ticky/profiling/tables next to code etc
255 -- so we can't use constant offsets from Constants
258 :: CmmLit -- closure type descr (profiling)
259 -> CmmLit -- closure descr (profiling)
260 -> StgHalfWord -- closure type
261 -> StgHalfWord -- SRT length
262 -> CmmLit -- layout field
265 mkStdInfoTable type_descr closure_descr cl_type srt_len layout_lit
266 = -- Parallel revertible-black hole field
268 -- Ticky info (none at present)
269 -- Debug info (none at present)
270 ++ [layout_lit, type_lit]
274 | opt_SccProfilingOn = [type_descr, closure_descr]
277 type_lit = packHalfWordsCLit cl_type srt_len
280 _unused :: FS.FastString -- stops a warning