6 #include "HsVersions.h"
31 cmmToRawCmm :: [Cmm] -> IO [RawCmm]
33 info_tbl_uniques <- mkSplitUniqSupply 'i'
34 return $ zipWith raw_cmm (listSplitUniqSupply info_tbl_uniques) cmm
36 raw_cmm uniq_supply (Cmm procs) =
37 Cmm $ concat $ zipWith mkInfoTable (uniqsFromSupply uniq_supply) procs
39 -- Make a concrete info table, represented as a list of CmmStatic
40 -- (it can't be simply a list of Word, because the SRT field is
41 -- represented by a label+offset expression).
43 -- With tablesNextToCode, the layout is
44 -- <reversed variable part>
45 -- <normal forward StgInfoTable, but without
46 -- an entry point at the front>
49 -- Without tablesNextToCode, the layout of an info table is
51 -- <normal forward rest of StgInfoTable>
52 -- <forward variable part>
54 -- See includes/InfoTables.h
56 -- For return-points these are as follows
58 -- Tables next to code:
61 -- <standard info table>
62 -- ret-addr --> <entry code (if any)>
64 -- Not tables-next-to-code:
66 -- ret-addr --> <ptr to entry code>
67 -- <standard info table>
70 -- * The SRT slot is only there if there is SRT info to record
72 mkInfoTable :: Unique -> CmmTop -> [RawCmmTop]
73 mkInfoTable uniq (CmmData sec dat) = [CmmData sec dat]
74 mkInfoTable uniq (CmmProc (CmmInfo _ _ info) entry_label arguments blocks) =
76 -- | Code without an info table. Easy.
77 CmmNonInfoTable -> [CmmProc [] entry_label arguments blocks]
79 CmmInfoTable (ProfilingInfo ty_prof cl_prof) type_tag type_info ->
80 let info_label = entryLblToInfoLbl entry_label
81 ty_prof' = if tablesNextToCode
82 then makeRelativeRefTo info_label ty_prof
84 cl_prof' = if tablesNextToCode
85 then makeRelativeRefTo info_label cl_prof
88 -- | A function entry point.
89 FunInfo (ptrs, nptrs) srt fun_type fun_arity pap_bitmap slow_entry ->
90 mkInfoTableAndCode info_label std_info fun_extra_bits entry_label
94 [packHalfWordsCLit fun_type fun_arity] ++
97 (if null srt_label then [mkIntCLit 0] else srt_label) ++
98 [makeRelativeRefTo info_label $ mkLivenessCLit liveness,
99 makeRelativeRefTo info_label slow_entry]
101 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag srt_bitmap
103 (srt_label, srt_bitmap) = mkSRTLit info_label srt
104 layout = packHalfWordsCLit ptrs nptrs
107 ConstrInfo (ptrs, nptrs) con_tag descr ->
108 mkInfoTableAndCode info_label std_info [con_name] entry_label
111 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag con_tag layout
112 con_name = makeRelativeRefTo info_label descr
113 layout = packHalfWordsCLit ptrs nptrs
116 ThunkInfo (ptrs, nptrs) srt ->
117 mkInfoTableAndCode info_label std_info srt_label entry_label
120 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag srt_bitmap layout
121 (srt_label, srt_bitmap) = mkSRTLit info_label srt
122 layout = packHalfWordsCLit ptrs nptrs
124 -- | A selector thunk.
125 ThunkSelectorInfo offset srt ->
126 mkInfoTableAndCode info_label std_info [{- no SRT -}] entry_label
129 std_info = mkStdInfoTable ty_prof' cl_prof' type_tag 0 (mkWordCLit offset)
131 -- A continuation/return-point.
132 ContInfo stack_layout srt ->
134 mkInfoTableAndCode info_label std_info srt_label entry_label
137 std_info = mkStdInfoTable ty_prof' cl_prof' maybe_big_type_tag srt_bitmap
138 (makeRelativeRefTo info_label liveness_lit)
139 (liveness_lit, liveness_data, liveness_tag) =
140 mkLiveness uniq stack_layout
141 maybe_big_type_tag = if type_tag == rET_SMALL
144 (srt_label, srt_bitmap) = mkSRTLit info_label srt
146 -- Handle the differences between tables-next-to-code
147 -- and not tables-next-to-code
148 mkInfoTableAndCode :: CLabel
155 mkInfoTableAndCode info_lbl std_info extra_bits entry_lbl args blocks
156 | tablesNextToCode -- Reverse the extra_bits; and emit the top-level proc
157 = [CmmProc (map CmmStaticLit (reverse extra_bits ++ std_info))
158 entry_lbl args blocks]
160 | null blocks -- No actual code; only the info table is significant
161 = -- Use a zero place-holder in place of the
162 -- entry-label in the info table
163 [mkRODataLits info_lbl (zeroCLit : std_info ++ extra_bits)]
165 | otherwise -- Separately emit info table (with the function entry
166 = -- point as first entry) and the entry code
167 [CmmProc [] entry_lbl args blocks,
168 mkDataLits info_lbl (CmmLabel entry_lbl : std_info ++ extra_bits)]
172 -> ([CmmLit], -- srt_label
173 StgHalfWord) -- srt_bitmap
174 mkSRTLit info_label NoC_SRT = ([], 0)
175 mkSRTLit info_label (C_SRT lbl off bitmap) =
176 ([makeRelativeRefTo info_label (cmmLabelOffW lbl off)], bitmap)
178 -------------------------------------------------------------------------
180 -- Build a liveness mask for the stack layout
182 -------------------------------------------------------------------------
184 -- There are four kinds of things on the stack:
186 -- - pointer variables (bound in the environment)
187 -- - non-pointer variables (bound in the environment)
188 -- - free slots (recorded in the stack free list)
189 -- - non-pointer data slots (recorded in the stack free list)
191 -- The first two are represented with a 'Just' of a 'LocalReg'.
192 -- The last two with one or more 'Nothing' constructors.
193 -- Each 'Nothing' represents one used word.
195 -- The head of the stack layout is the top of the stack and
196 -- the least-significant bit.
198 -- TODO: refactor to use utility functions
199 -- TODO: combine with CgCallConv.mkLiveness (see comment there)
202 -> (CmmLit, -- ^ The bitmap (literal value or label)
203 [RawCmmTop], -- ^ Large bitmap CmmData if needed
204 ClosureTypeTag) -- ^ rET_SMALL or rET_BIG
205 mkLiveness uniq live =
206 if length bits > mAX_SMALL_BITMAP_SIZE
207 -- does not fit in one word
208 then (CmmLabel big_liveness, [data_lits], rET_BIG)
210 else (mkWordCLit small_liveness, [], rET_SMALL)
213 mkBits (reg:regs) = take sizeW bits ++ mkBits regs where
216 Just r -> (machRepByteWidth (localRegRep r) + wORD_SIZE - 1)
218 -- number of words, rounded up
219 bits = repeat $ is_non_ptr reg -- True <=> Non Ptr
221 is_non_ptr Nothing = True
222 is_non_ptr (Just reg) =
223 case localRegGCFollow reg of
231 bitmap = mkBitmap bits
233 small_bitmap = case bitmap of
235 [b] -> fromIntegral b
236 _ -> panic "mkLiveness"
238 fromIntegral (length bits) .|. (small_bitmap `shiftL` bITMAP_BITS_SHIFT)
240 big_liveness = mkBitmapLabel uniq
241 lits = mkWordCLit (fromIntegral (length bits)) : map mkWordCLit bitmap
242 data_lits = mkRODataLits big_liveness lits
244 -------------------------------------------------------------------------
246 -- Generating a standard info table
248 -------------------------------------------------------------------------
250 -- The standard bits of an info table. This part of the info table
251 -- corresponds to the StgInfoTable type defined in InfoTables.h.
253 -- Its shape varies with ticky/profiling/tables next to code etc
254 -- so we can't use constant offsets from Constants
257 :: CmmLit -- closure type descr (profiling)
258 -> CmmLit -- closure descr (profiling)
259 -> StgHalfWord -- closure type
260 -> StgHalfWord -- SRT length
261 -> CmmLit -- layout field
264 mkStdInfoTable type_descr closure_descr cl_type srt_len layout_lit
265 = -- Parallel revertible-black hole field
267 -- Ticky info (none at present)
268 -- Debug info (none at present)
269 ++ [layout_lit, type_lit]
273 | opt_SccProfilingOn = [type_descr, closure_descr]
276 type_lit = packHalfWordsCLit cl_type srt_len