2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[CostCentre]{The @CostCentre@ data type}
8 CostCentre(..), CcName, IsDupdCC(..), IsCafCC(..), IsDictCC(..),
9 -- All abstract except to friend: ParseIface.y
12 noCCS, subsumedCCS, currentCCS, overheadCCS, dontCareCCS,
13 noCostCentre, noCCAttached,
14 noCCSAttached, isCurrentCCS, isSubsumedCCS, currentOrSubsumedCCS,
16 mkUserCC, mkAutoCC, mkDictCC, mkAllCafsCC, mkAllDictsCC,
17 mkSingletonCCS, cafifyCC, dupifyCC,
18 isCafCC, isDictCC, isDupdCC, isEmptyCC, isCafCCS,
23 pprCostCentreDecl, pprCostCentreStackDecl, pprCostCentreCore,
25 cmpCostCentre -- used for removing dups in a list
28 #include "HsVersions.h"
31 import Name ( UserFS, EncodedFS, encodeFS, decode,
34 import Module ( Module, pprModule, moduleUserString )
36 import Util ( thenCmp )
39 A Cost Centre Stack is something that can be attached to a closure.
42 - the current cost centre stack (CCCS)
43 - a pre-defined cost centre stack (there are several
44 pre-defined CCSs, see below).
50 | CurrentCCS -- Pinned on a let(rec)-bound
51 -- thunk/function/constructor, this says that the
52 -- cost centre to be attached to the object, when it
53 -- is allocated, is whatever is in the
54 -- current-cost-centre-stack register.
56 | SubsumedCCS -- Cost centre stack for top-level subsumed functions
57 -- (CAFs get an AllCafsCC).
58 -- Its execution costs get subsumed into the caller.
59 -- This guy is *only* ever pinned on static closures,
60 -- and is *never* the cost centre for an SCC construct.
62 | OverheadCCS -- We charge costs due to the profiling-system
63 -- doing its work to "overhead".
65 -- Objects whose CCS is "Overhead"
66 -- have their *allocation* charged to "overhead",
67 -- but have the current CCS put into the object
70 -- For example, if we transform "f g" to "let
71 -- g' = g in f g'" (so that something about
72 -- profiling works better...), then we charge
73 -- the *allocation* of g' to OverheadCCS, but
74 -- we put the cost-centre of the call to f
75 -- (i.e., current CCS) into the g' object. When
76 -- g' is entered, the CCS of the call
79 | DontCareCCS -- We need a CCS to stick in static closures
80 -- (for data), but we *don't* expect them to
81 -- accumulate any costs. But we still need
82 -- the placeholder. This CCS is it.
84 | SingletonCCS CostCentre
85 -- This is primarily for CAF cost centres, which
86 -- are attached to top-level thunks right at the
87 -- end of STG processing, before code generation.
88 -- Hence, a CAF cost centre never appears as the
89 -- argument of an _scc_.
90 -- Also, we generate these singleton CCSs statically
91 -- as part of code generation.
93 deriving (Eq, Ord) -- needed for Ord on CLabel
96 A Cost Centre is the argument of an _scc_ expression.
99 type Group = FAST_STRING -- "Group" that this CC is in; eg directory
102 = NoCostCentre -- Having this constructor avoids having
103 -- to use "Maybe CostCentre" all the time.
106 cc_name :: CcName, -- Name of the cost centre itself
107 cc_mod :: Module, -- Name of module defining this CC.
108 cc_grp :: Group, -- "Group" that this CC is in.
109 cc_is_dict :: IsDictCC, -- see below
110 cc_is_dupd :: IsDupdCC, -- see below
111 cc_is_caf :: IsCafCC -- see below
115 cc_mod :: Module, -- Name of module defining this CC.
116 cc_grp :: Group -- "Group" that this CC is in
117 -- Again, one "big" CAF cc per module, where all
118 -- CAF costs are attributed unless the user asked for
119 -- per-individual-CAF cost attribution.
123 cc_mod :: Module, -- Name of module defining this CC.
124 cc_grp :: Group, -- "Group" that this CC is in.
125 -- Again, one "big" DICT cc per module, where all
126 -- DICT costs are attributed unless the user asked for
127 -- per-individual-DICT cost attribution.
128 cc_is_dupd :: IsDupdCC
131 type CcName = EncodedFS
133 data IsDictCC = DictCC | VanillaCC
136 = OriginalCC -- This says how the CC is *used*. Saying that
137 | DupdCC -- it is DupdCC doesn't make it a different
138 -- CC, just that it a sub-expression which has
139 -- been moved ("dupd") into a different scope.
141 -- The point about a dupd SCC is that we don't
142 -- count entries to it, because it's not the
145 -- In the papers, it's called "SCCsub",
146 -- i.e. SCCsub CC == SCC DupdCC,
147 -- but we are trying to avoid confusion between
148 -- "subd" and "subsumed". So we call the former
151 data IsCafCC = CafCC | NotCafCC
154 WILL: Would there be any merit to recording ``I am now using a
155 cost-centre from another module''? I don't know if this would help a
156 user; it might be interesting to us to know how much computation is
157 being moved across module boundaries.
159 SIMON: Maybe later...
164 subsumedCCS = SubsumedCCS
165 currentCCS = CurrentCCS
166 overheadCCS = OverheadCCS
167 dontCareCCS = DontCareCCS
169 noCostCentre = NoCostCentre
172 Predicates on Cost-Centre Stacks
175 noCCSAttached NoCCS = True
176 noCCSAttached _ = False
178 noCCAttached NoCostCentre = True
179 noCCAttached _ = False
181 isCurrentCCS CurrentCCS = True
182 isCurrentCCS _ = False
184 isSubsumedCCS SubsumedCCS = True
185 isSubsumedCCS _ = False
187 isCafCCS (SingletonCCS cc) = isCafCC cc
190 isDictCCS (SingletonCCS cc) = isDictCC cc
193 currentOrSubsumedCCS SubsumedCCS = True
194 currentOrSubsumedCCS CurrentCCS = True
195 currentOrSubsumedCCS _ = False
198 Building cost centres
201 mkUserCC :: UserFS -> Module -> Group -> CostCentre
203 mkUserCC cc_name module_name group_name
204 = NormalCC { cc_name = encodeFS cc_name,
205 cc_mod = module_name, cc_grp = group_name,
206 cc_is_dict = VanillaCC, cc_is_dupd = OriginalCC, cc_is_caf = NotCafCC {-might be changed-}
209 mkDictCC, mkAutoCC :: Id -> Module -> Group -> IsCafCC -> CostCentre
211 mkDictCC id module_name group_name is_caf
212 = NormalCC { cc_name = occNameFS (getOccName id),
213 cc_mod = module_name, cc_grp = group_name,
214 cc_is_dict = DictCC, cc_is_dupd = OriginalCC, cc_is_caf = is_caf
217 mkAutoCC id module_name group_name is_caf
218 = NormalCC { cc_name = occNameFS (getOccName id),
219 cc_mod = module_name, cc_grp = group_name,
220 cc_is_dict = VanillaCC, cc_is_dupd = OriginalCC, cc_is_caf = is_caf
223 mkAllCafsCC m g = AllCafsCC { cc_mod = m, cc_grp = g }
224 mkAllDictsCC m g is_dupd = AllDictsCC { cc_mod = m, cc_grp = g,
225 cc_is_dupd = if is_dupd then DupdCC else OriginalCC }
227 mkSingletonCCS :: CostCentre -> CostCentreStack
228 mkSingletonCCS cc = SingletonCCS cc
230 cafifyCC, dupifyCC :: CostCentre -> CostCentre
232 cafifyCC cc@(AllDictsCC {}) = cc
233 cafifyCC cc@(NormalCC {cc_is_caf = is_caf})
234 = ASSERT(not_a_caf_already is_caf)
235 cc {cc_is_caf = CafCC}
237 not_a_caf_already CafCC = False
238 not_a_caf_already _ = True
239 cafifyCC cc = pprPanic "cafifyCC" (ppr cc)
241 dupifyCC cc = cc {cc_is_dupd = DupdCC}
243 isEmptyCC, isCafCC, isDictCC, isDupdCC :: CostCentre -> Bool
245 isEmptyCC (NoCostCentre) = True
248 isCafCC (AllCafsCC {}) = True
249 isCafCC (NormalCC {cc_is_caf = CafCC}) = True
252 isDictCC (AllDictsCC {}) = True
253 isDictCC (NormalCC {cc_is_dict = DictCC}) = True
256 isDupdCC (AllDictsCC {cc_is_dupd = DupdCC}) = True
257 isDupdCC (NormalCC {cc_is_dupd = DupdCC}) = True
260 isSccCountCostCentre :: CostCentre -> Bool
261 -- Is this a cost-centre which records scc counts
264 isSccCountCostCentre NoCostCentre = panic "isSccCount:NoCostCentre"
266 isSccCountCostCentre cc | isCafCC cc = False
267 | isDupdCC cc = False
271 sccAbleCostCentre :: CostCentre -> Bool
272 -- Is this a cost-centre which can be sccd ?
275 sccAbleCostCentre NoCostCentre = panic "sccAbleCC:NoCostCentre"
277 sccAbleCostCentre cc | isCafCC cc = False
280 ccFromThisModule :: CostCentre -> Module -> Bool
281 ccFromThisModule cc m = cc_mod cc == m
285 instance Eq CostCentre where
286 c1 == c2 = case c1 `cmpCostCentre` c2 of { EQ -> True; _ -> False }
288 instance Ord CostCentre where
289 compare = cmpCostCentre
291 cmpCostCentre :: CostCentre -> CostCentre -> Ordering
293 cmpCostCentre (AllCafsCC {cc_mod = m1}) (AllCafsCC {cc_mod = m2}) = m1 `compare` m2
294 cmpCostCentre (AllDictsCC {cc_mod = m1}) (AllDictsCC {cc_mod = m2}) = m1 `compare` m2
296 cmpCostCentre (NormalCC {cc_name = n1, cc_mod = m1, cc_is_caf = c1})
297 (NormalCC {cc_name = n2, cc_mod = m2, cc_is_caf = c2})
298 -- first key is module name, then we use "kinds" (which include
299 -- names) and finally the caf flag
300 = (m1 `compare` m2) `thenCmp` (n1 `compare` n2) `thenCmp` (c1 `cmp_caf` c2)
302 cmpCostCentre other_1 other_2
304 tag1 = tag_CC other_1
305 tag2 = tag_CC other_2
307 if tag1 _LT_ tag2 then LT else GT
309 tag_CC (NormalCC {}) = (ILIT(1) :: FAST_INT)
310 tag_CC (AllCafsCC {}) = ILIT(2)
311 tag_CC (AllDictsCC {}) = ILIT(3)
313 cmp_caf NotCafCC CafCC = LT
314 cmp_caf NotCafCC NotCafCC = EQ
315 cmp_caf CafCC CafCC = EQ
316 cmp_caf CafCC NotCafCC = GT
319 -----------------------------------------------------------------------------
320 Printing Cost Centre Stacks.
322 There are two ways to print a CCS:
324 - for debugging output (i.e. -ddump-whatever),
328 instance Outputable CostCentreStack where
329 ppr ccs = case ccs of
330 NoCCS -> ptext SLIT("NO_CCS")
331 CurrentCCS -> ptext SLIT("CCCS")
332 OverheadCCS -> ptext SLIT("CCS_OVERHEAD")
333 DontCareCCS -> ptext SLIT("CCS_DONTZuCARE")
334 SubsumedCCS -> ptext SLIT("CCS_SUBSUMED")
335 SingletonCCS cc -> ptext SLIT("CCS_") <> ppr cc
337 pprCostCentreStackDecl :: CostCentreStack -> SDoc
338 pprCostCentreStackDecl ccs@(SingletonCCS cc)
340 is_subsumed = ccSubsumed cc
342 hcat [ ptext SLIT("CCS_DECLARE"), char '(',
343 ppr ccs, comma, -- better be codeStyle
344 ppCostCentreLbl cc, comma,
345 ptext is_subsumed, comma,
346 empty, -- Now always externally visible
350 pprCostCentreStackDecl ccs
351 = pprPanic "pprCostCentreStackDecl: " (ppr ccs)
354 -----------------------------------------------------------------------------
355 Printing Cost Centres.
357 There are several different ways in which we might want to print a
360 - the name of the cost centre, for profiling output (a C string)
361 - the label, i.e. C label for cost centre in .hc file.
362 - the debugging name, for output in -ddump things
363 - the interface name, for printing in _scc_ exprs in iface files.
365 The last 3 are derived from costCentreStr below. The first is given
369 instance Outputable CostCentre where
370 ppr cc = getPprStyle $ \ sty ->
372 then ppCostCentreLbl cc
373 else text (costCentreUserName cc)
375 -- Printing in an interface file or in Core generally
376 pprCostCentreCore (AllCafsCC {cc_mod = m, cc_grp = g})
377 = text "__sccC" <+> braces (pprModule m <+> doubleQuotes (ptext g))
378 pprCostCentreCore (AllDictsCC {cc_mod = m, cc_grp = g, cc_is_dupd = dup})
379 = text "__sccD" <+> braces (pprModule m <+> doubleQuotes (ptext g) <+> pp_dup dup)
380 pprCostCentreCore (NormalCC {cc_name = n, cc_mod = m, cc_grp = g,
381 cc_is_dict = dic, cc_is_caf = caf, cc_is_dupd = dup})
382 = text "__scc" <+> braces (hsep [
385 doubleQuotes (ptext g),
391 pp_dict DictCC = text "__A"
392 pp_dict other = empty
394 pp_dup DupdCC = char '!'
397 pp_caf CafCC = text "__C"
401 -- Printing as a C label
402 ppCostCentreLbl (NoCostCentre) = text "CC_NONE"
403 ppCostCentreLbl (AllCafsCC {cc_mod = m}) = text "CC_CAFs_" <> pprModule m
404 ppCostCentreLbl (AllDictsCC {cc_mod = m}) = text "CC_DICTs_" <> pprModule m
405 ppCostCentreLbl (NormalCC {cc_name = n, cc_mod = m}) = text "CC_" <> pprModule m <> ptext n
407 -- This is the name to go in the user-displayed string,
408 -- recorded in the cost centre declaration
409 costCentreUserName (NoCostCentre) = "NO_CC"
410 costCentreUserName (AllCafsCC {}) = "CAFs_in_..."
411 costCentreUserName (AllDictsCC {}) = "DICTs_in_..."
412 costCentreUserName (NormalCC {cc_name = name, cc_is_caf = is_caf})
413 = case is_caf of { CafCC -> "CAF:"; _ -> "" } ++ decode (_UNPK_ name)
416 Cost Centre Declarations
420 pprCostCentreDecl is_local (NoCostCentre)
421 = panic "pprCostCentreDecl: no cost centre!"
423 pprCostCentreDecl is_local cc
426 ptext SLIT("CC_DECLARE"),char '(',
428 doubleQuotes (text (costCentreUserName cc)), comma,
429 doubleQuotes (text (moduleUserString mod_name)), comma,
430 doubleQuotes (ptext grp_name), comma,
431 ptext is_subsumed, comma,
432 empty, -- Now always externally visible
435 hcat [ ptext SLIT("CC_EXTERN"),char '(', cc_ident, text ");" ]
437 cc_ident = ppCostCentreLbl cc
440 is_subsumed = ccSubsumed cc
442 ccSubsumed :: CostCentre -> FAST_STRING -- subsumed value
443 ccSubsumed cc | isCafCC cc = SLIT("CC_IS_CAF")
444 | isDictCC cc = SLIT("CC_IS_DICT")
445 | otherwise = SLIT("CC_IS_BORING")