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Andreas Klebinger pushed to branch wip/andreask/occ_anal_tuning at Glasgow Haskell Compiler / GHC

Commits:

cb1ea0c9

by Andreas Klebinger at 2025-10-27T18:43:40+01:00

OccAnal: Be stricter.

* When combining usageDetails.
* When constructing core expressions.

In combineUsageDetails when combining the underlying adds we compute a
new `LocalOcc` for each entry by combining the two existing ones.

Rather than wait for those entries to be forced down the road we now
force them immediately. Speeding up T26425 by about 10% with little
effect on the common case.

We also force binders we put into the Core AST everywhere now.
Failure to do so risks leaking the occ env used to set the binders
OccInfo.

For T26425 compiler residency went down by a factor of ~10x.

Compile time also improved by a factor of ~1.6.

-------------------------
Metric Decrease:
    T26425
-------------------------

1434feb8
by Andreas Klebinger at 2025-10-27T18:47:18+01:00
```
Add a perf test for #26425
```

6 changed files:

compiler/GHC/Core/Opt/OccurAnal.hs
compiler/GHC/Data/Graph/UnVar.hs
compiler/GHC/Types/Unique/FM.hs
compiler/GHC/Types/Var/Env.hs
+ testsuite/tests/perf/compiler/T26425.hs
testsuite/tests/perf/compiler/all.T

Changes:

compiler/GHC/Core/Opt/OccurAnal.hs

@@ -9,6 +9,8 @@
  -- many /other/ arguments the function has.  Inconsistent unboxing is very
  -- bad for performance, so I increased the limit to allow it to unbox
  -- consistently.
 +-- AK: Seems we no longer unbox OccEnv now anyway so it might be redundant.
++
  {-
  (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
@@ -967,6 +969,11 @@ occAnalBind
    -> ([CoreBind] -> r -> r)          -- How to combine the scope with new binds
    -> WithUsageDetails r              -- Of the whole let(rec)
 +-- While not allocating any less inlining occAnalBind turns calls to the passed functions
 +-- into known calls. One might assume this doesn't matter, but for let heavy
 +-- code I observed speed ups as big as 10-20%!
 +{-# INLINE occAnalBind #-}
++
  occAnalBind env lvl ire (Rec pairs) thing_inside combine
    = addInScopeList env (map fst pairs) $ \env ->
      let WUD body_uds body'  = thing_inside env
@@ -984,7 +991,7 @@ occAnalBind !env lvl ire (NonRec bndr rhs) thing_inside combine
    = -- Analyse the RHS and /then/ the body
      let -- Analyse the rhs first, generating rhs_uds
          !(rhs_uds_s, bndr', rhs') = occAnalNonRecRhs env lvl ire mb_join bndr rhs
 -        rhs_uds = foldr1 orUDs rhs_uds_s   -- NB: orUDs.  See (W4) of
 +        rhs_uds = foldl1' orUDs rhs_uds_s   -- NB: orUDs.  See (W4) of
                                             -- Note [Occurrence analysis for join points]
          -- Now analyse the body, adding the join point
@@ -1049,6 +1056,7 @@ occAnalNonRecRhs !env lvl imp_rule_edges mb_join bndr rhs
      -- Match join arity O from mb_join_arity with manifest join arity M as
      -- returned by of occAnalLamTail. It's totally OK for them to mismatch;
      -- hence adjust the UDs from the RHS
++
      WUD adj_rhs_uds final_rhs = adjustNonRecRhs mb_join $
                                  occAnalLamTail rhs_env rhs
      final_bndr_with_rules
@@ -2188,7 +2196,8 @@ occ_anal_lam_tail env expr@(Lam {})
      go env rev_bndrs body
        = addInScope env rev_bndrs $ \env ->
          let !(WUD usage body') = occ_anal_lam_tail env body
 -            wrap_lam body bndr = Lam (tagLamBinder usage bndr) body
 +            wrap_lam !body !bndr = let !bndr' = tagLamBinder usage bndr
 +                                   in Lam bndr' body
          in WUD (usage `addLamCoVarOccs` rev_bndrs)
                 (foldl' wrap_lam body' rev_bndrs)
@@ -2541,7 +2550,7 @@ occAnal env (Case scrut bndr ty alts)
             let alt_env = addBndrSwap scrut' bndr $
                           setTailCtxt env  -- Kill off OccRhs
                 WUD alts_usage alts' = do_alts alt_env alts
 -               tagged_bndr = tagLamBinder alts_usage bndr
 +               !tagged_bndr = tagLamBinder alts_usage bndr
             in WUD alts_usage (tagged_bndr, alts')
        total_usage = markAllNonTail scrut_usage `andUDs` alts_usage
@@ -2559,11 +2568,12 @@ occAnal env (Case scrut bndr ty alts)
      do_alt !env (Alt con bndrs rhs)
        = addInScopeList env bndrs $ \ env ->
          let WUD rhs_usage rhs' = occAnal env rhs
 -            tagged_bndrs = tagLamBinders rhs_usage bndrs
 +            !tagged_bndrs = tagLamBinders rhs_usage bndrs
          in                 -- See Note [Binders in case alternatives]
          WUD rhs_usage (Alt con tagged_bndrs rhs')
  occAnal env (Let bind body)
 +  -- TODO: Would be nice to use a strict version of mkLets here
    = occAnalBind env NotTopLevel noImpRuleEdges bind
                  (\env -> occAnal env body) mkLets
@@ -2644,10 +2654,12 @@ occAnalApp !env (Var fun, args, ticks)
    | fun `hasKey` runRWKey
    , [t1, t2, arg]  <- args
    , WUD usage arg' <- adjustNonRecRhs (JoinPoint 1) $ occAnalLamTail env arg
 -  = WUD usage (mkTicks ticks $ mkApps (Var fun) [t1, t2, arg'])
 +  = let app_out = (mkTicks ticks $ mkApps (Var fun) [t1, t2, arg'])
 +    in WUD usage app_out
  occAnalApp env (Var fun_id, args, ticks)
 -  = WUD all_uds (mkTicks ticks app')
 +  = let app_out = (mkTicks ticks app')
 +    in WUD all_uds app_out
    where
      -- Lots of banged bindings: this is a very heavily bit of code,
      -- so it pays not to make lots of thunks here, all of which
@@ -2692,8 +2704,9 @@ occAnalApp env (Var fun_id, args, ticks)
          -- See Note [Sources of one-shot information], bullet point A']
  occAnalApp env (fun, args, ticks)
 -  = WUD (markAllNonTail (fun_uds `andUDs` args_uds))
 -                     (mkTicks ticks app')
 +  = let app_out = (mkTicks ticks app')
 +    in WUD (markAllNonTail (fun_uds `andUDs` args_uds)) app_out
++
    where
      !(WUD args_uds app') = occAnalArgs env fun' args []
      !(WUD fun_uds fun')  = occAnal (addAppCtxt env args) fun
@@ -3650,8 +3663,8 @@ data WithTailUsageDetails a = WTUD !TailUsageDetails !a
  -------------------
  -- UsageDetails API
 -andUDs, orUDs
 -        :: UsageDetails -> UsageDetails -> UsageDetails
 +andUDs:: UsageDetails -> UsageDetails -> UsageDetails
 +orUDs :: UsageDetails -> UsageDetails -> UsageDetails
  andUDs = combineUsageDetailsWith andLocalOcc
  orUDs  = combineUsageDetailsWith orLocalOcc
@@ -3766,10 +3779,12 @@ combineUsageDetailsWith plus_occ_info
    | isEmptyVarEnv env1 = uds2
    | isEmptyVarEnv env2 = uds1
    | otherwise
 -  = UD { ud_env       = plusVarEnv_C plus_occ_info env1 env2
 -       , ud_z_many    = plusVarEnv z_many1   z_many2
 +  -- Using strictPlusVarEnv here speeds up the test T26425 by about 10% by avoiding
 +  -- intermediate thunks.
 +  = UD { ud_env       = strictPlusVarEnv_C plus_occ_info env1 env2
 +       , ud_z_many    = strictPlusVarEnv z_many1   z_many2
         , ud_z_in_lam  = plusVarEnv z_in_lam1 z_in_lam2
 -       , ud_z_tail    = plusVarEnv z_tail1   z_tail2 }
 +       , ud_z_tail    = strictPlusVarEnv z_tail1   z_tail2 }
  lookupLetOccInfo :: UsageDetails -> Id -> OccInfo
  -- Don't use locally-generated occ_info for exported (visible-elsewhere)
@@ -3847,7 +3862,7 @@ tagLamBinders :: UsageDetails        -- Of scope
                -> [Id]                -- Binders
                -> [IdWithOccInfo]     -- Tagged binders
  tagLamBinders usage binders
 -  = map (tagLamBinder usage) binders
 +  = strictMap (tagLamBinder usage) binders
  tagLamBinder :: UsageDetails       -- Of scope
               -> Id                 -- Binder

compiler/GHC/Data/Graph/UnVar.hs

@@ -17,8 +17,8 @@ equal to g, but twice as expensive and large.
  module GHC.Data.Graph.UnVar
      ( UnVarSet
      , emptyUnVarSet, mkUnVarSet, unionUnVarSet, unionUnVarSets
 -    , extendUnVarSet, extendUnVarSetList, delUnVarSet, delUnVarSetList
 -    , elemUnVarSet, isEmptyUnVarSet
 +    , extendUnVarSet, extendUnVarSet_Directly, extendUnVarSetList, delUnVarSet, delUnVarSetList
 +    , elemUnVarSet, elemUnVarSet_Directly, isEmptyUnVarSet
      , UnVarGraph
      , emptyUnVarGraph
      , unionUnVarGraph, unionUnVarGraphs
@@ -60,6 +60,9 @@ emptyUnVarSet = UnVarSet S.empty
  elemUnVarSet :: Var -> UnVarSet -> Bool
  elemUnVarSet v (UnVarSet s) = k v `S.member` s
 +{-# INLINE elemUnVarSet_Directly #-}
 +elemUnVarSet_Directly :: Uniquable key => key -> UnVarSet -> Bool
 +elemUnVarSet_Directly v (UnVarSet s) = (getKey $ getUnique v) `S.member` s
  isEmptyUnVarSet :: UnVarSet -> Bool
  isEmptyUnVarSet (UnVarSet s) = S.null s
@@ -82,6 +85,10 @@ mkUnVarSet vs = UnVarSet $ S.fromList $ map k vs
  extendUnVarSet :: Var -> UnVarSet -> UnVarSet
  extendUnVarSet v (UnVarSet s) = UnVarSet $ S.insert (k v) s
 +{-# INLINE extendUnVarSet_Directly #-}
 +extendUnVarSet_Directly :: Uniquable key => key -> UnVarSet -> UnVarSet
 +extendUnVarSet_Directly u (UnVarSet s) = UnVarSet $ S.insert (getKey $ getUnique u) s
++
  extendUnVarSetList :: [Var] -> UnVarSet -> UnVarSet
  extendUnVarSetList vs s = s `unionUnVarSet` mkUnVarSet vs

compiler/GHC/Types/Unique/FM.hs

@@ -51,7 +51,9 @@ module GHC.Types.Unique.FM (
          delListFromUFM,
          delListFromUFM_Directly,
          plusUFM,
 +        strictPlusUFM,
          plusUFM_C,
 +        strictPlusUFM_C,
          plusUFM_CD,
          plusUFM_CD2,
          mergeUFM,
@@ -261,16 +263,24 @@ delListFromUFM_Directly = foldl' delFromUFM_Directly
  delFromUFM_Directly :: UniqFM key elt -> Unique -> UniqFM key elt
  delFromUFM_Directly (UFM m) u = UFM (M.delete (getKey u) m)
 --- Bindings in right argument shadow those in the left
 +-- | Bindings in right argument shadow those in the left.
 +--
 +-- Unlike containers this union is right-biased for historic reasons.
  plusUFM :: UniqFM key elt -> UniqFM key elt -> UniqFM key elt
 --- M.union is left-biased, plusUFM should be right-biased.
  plusUFM (UFM x) (UFM y) = UFM (M.union y x)
       -- Note (M.union y x), with arguments flipped
       -- M.union is left-biased, plusUFM should be right-biased.
 +-- | Right biased
 +strictPlusUFM :: UniqFM key elt -> UniqFM key elt -> UniqFM key elt
 +strictPlusUFM (UFM x) (UFM y) = UFM (MS.union y x)
++
  plusUFM_C :: (elt -> elt -> elt) -> UniqFM key elt -> UniqFM key elt -> UniqFM key elt
  plusUFM_C f (UFM x) (UFM y) = UFM (M.unionWith f x y)
 +strictPlusUFM_C :: (elt -> elt -> elt) -> UniqFM key elt -> UniqFM key elt -> UniqFM key elt
 +strictPlusUFM_C f (UFM x) (UFM y) = UFM (MS.unionWith f x y)
++
  -- | `plusUFM_CD f m1 d1 m2 d2` merges the maps using `f` as the
  -- combinding function and `d1` resp. `d2` as the default value if
  -- there is no entry in `m1` reps. `m2`. The domain is the union of

compiler/GHC/Types/Var/Env.hs

@@ -12,7 +12,8 @@ module GHC.Types.Var.Env (
          elemVarEnv, disjointVarEnv, anyVarEnv,
          extendVarEnv, extendVarEnv_C, extendVarEnv_Acc,
          extendVarEnvList,
 -        plusVarEnv, plusVarEnv_C, plusVarEnv_CD, plusMaybeVarEnv_C,
 +        strictPlusVarEnv, plusVarEnv, plusVarEnv_C, strictPlusVarEnv_C,
 +        plusVarEnv_CD, plusMaybeVarEnv_C,
          plusVarEnvList, alterVarEnv,
          delVarEnvList, delVarEnv,
          minusVarEnv,
@@ -511,6 +512,7 @@ extendVarEnv      :: VarEnv a -> Var -> a -> VarEnv a
  extendVarEnv_C    :: (a->a->a) -> VarEnv a -> Var -> a -> VarEnv a
  extendVarEnv_Acc  :: (a->b->b) -> (a->b) -> VarEnv b -> Var -> a -> VarEnv b
  plusVarEnv        :: VarEnv a -> VarEnv a -> VarEnv a
 +strictPlusVarEnv  :: VarEnv a -> VarEnv a -> VarEnv a
  plusVarEnvList    :: [VarEnv a] -> VarEnv a
  extendVarEnvList  :: VarEnv a -> [(Var, a)] -> VarEnv a
  varEnvDomain      :: VarEnv elt -> UnVarSet
@@ -522,6 +524,7 @@ delVarEnvList     :: Foldable f => VarEnv a -> f Var -> VarEnv a
  delVarEnv         :: VarEnv a -> Var -> VarEnv a
  minusVarEnv       :: VarEnv a -> VarEnv b -> VarEnv a
  plusVarEnv_C      :: (a -> a -> a) -> VarEnv a -> VarEnv a -> VarEnv a
 +strictPlusVarEnv_C :: (a -> a -> a) -> VarEnv a -> VarEnv a -> VarEnv a
  plusVarEnv_CD     :: (a -> a -> a) -> VarEnv a -> a -> VarEnv a -> a -> VarEnv a
  plusMaybeVarEnv_C :: (a -> a -> Maybe a) -> VarEnv a -> VarEnv a -> VarEnv a
  mapVarEnv         :: (a -> b) -> VarEnv a -> VarEnv b
@@ -548,6 +551,7 @@ extendVarEnv_C   = addToUFM_C
  extendVarEnv_Acc = addToUFM_Acc
  extendVarEnvList = addListToUFM
  plusVarEnv_C     = plusUFM_C
 +strictPlusVarEnv_C = strictPlusUFM_C
  plusVarEnv_CD    = plusUFM_CD
  plusMaybeVarEnv_C = plusMaybeUFM_C
  delVarEnvList    = delListFromUFM
@@ -556,6 +560,7 @@ delVarEnvList    = delListFromUFM
  delVarEnv        = delFromUFM
  minusVarEnv      = minusUFM
  plusVarEnv       = plusUFM
 +strictPlusVarEnv = strictPlusUFM
  plusVarEnvList   = plusUFMList
  -- lookupVarEnv is very hot (in part due to being called by substTyVar),
  -- if it's not inlined than the mere allocation of the Just constructor causes

testsuite/tests/perf/compiler/T26425.hs

 +{-# LANGUAGE OverloadedStrings #-}
++
 +module Reproducer (strToInt) where
++
 +import qualified Data.Text as T
++
 +{- This program results in a nested chain of join points and cases which tests
 +   primarily OccAnal and Unfolding performance.
 +-}
++
 +strToInt :: T.Text -> Maybe Int
 +strToInt txt = case txt of
 +    "0" -> Just 0
 +    "1" -> Just 1
 +    "2" -> Just 2
 +    "3" -> Just 3
 +    "4" -> Just 4
 +    "5" -> Just 5
 +    "6" -> Just 6
 +    "7" -> Just 7
 +    "8" -> Just 8
 +    "9" -> Just 9
 +    "10" -> Just 10
 +    "11" -> Just 11
 +    "12" -> Just 12
 +    "13" -> Just 13
 +    "14" -> Just 14
 +    "15" -> Just 15
 +    "16" -> Just 16
 +    "17" -> Just 17
 +    "18" -> Just 18
 +    "19" -> Just 19
 +    "20" -> Just 20
 +    "21" -> Just 21
 +    "22" -> Just 22
 +    "23" -> Just 23
 +    "24" -> Just 24
 +    "25" -> Just 25
 +    "26" -> Just 26
 +    "27" -> Just 27
 +    "28" -> Just 28
 +    "29" -> Just 29
 +    "30" -> Just 30
 +    "31" -> Just 31
 +    "32" -> Just 32
 +    "33" -> Just 33
 +    "34" -> Just 34
 +    "35" -> Just 35
 +    "36" -> Just 36
 +    "37" -> Just 37
 +    "38" -> Just 38
 +    "39" -> Just 39
 +    "40" -> Just 40
 +    "41" -> Just 41
 +    "42" -> Just 42
 +    "43" -> Just 43
 +    "44" -> Just 44
 +    "45" -> Just 45
 +    "46" -> Just 46
 +    "47" -> Just 47
 +    "48" -> Just 48
 +    "49" -> Just 49
 +    "50" -> Just 50
 +    "51" -> Just 51
 +    "52" -> Just 52
 +    "53" -> Just 53
 +    "54" -> Just 54
 +    "55" -> Just 55
 +    "56" -> Just 56
 +    "57" -> Just 57
 +    "58" -> Just 58
 +    "59" -> Just 59
 +    "60" -> Just 60
 +    "61" -> Just 61
 +    "62" -> Just 62
 +    "63" -> Just 63
 +    "64" -> Just 64
 +    "65" -> Just 65
 +    "66" -> Just 66
 +    "67" -> Just 67
 +    "68" -> Just 68
 +    "69" -> Just 69
 +    "70" -> Just 70
 +    "71" -> Just 71
 +    "72" -> Just 72
 +    "73" -> Just 73
 +    "74" -> Just 74
 +    "75" -> Just 75
 +    "76" -> Just 76
 +    "77" -> Just 77
 +    "78" -> Just 78
 +    "79" -> Just 79
 +    "80" -> Just 80
 +    "81" -> Just 81
 +    "82" -> Just 82
 +    "83" -> Just 83
 +    "84" -> Just 84
 +    "85" -> Just 85
 +    "86" -> Just 86
 +    "87" -> Just 87
 +    "88" -> Just 88
 +    "89" -> Just 89
 +    "90" -> Just 90
 +    "91" -> Just 91
 +    "92" -> Just 92
 +    "93" -> Just 93
 +    "94" -> Just 94
 +    "95" -> Just 95
 +    "96" -> Just 96
 +    "97" -> Just 97
 +    "98" -> Just 98
 +    "99" -> Just 99
 +    "100" -> Just 100
 +    "101" -> Just 101
 +    "102" -> Just 102
 +    "103" -> Just 103
 +    "104" -> Just 104
 +    "105" -> Just 105
 +    "106" -> Just 106
 +    "107" -> Just 107
 +    "108" -> Just 108
 +    "109" -> Just 109
 +    "110" -> Just 110
 +    "111" -> Just 111
 +    "112" -> Just 112
 +    "113" -> Just 113
 +    "114" -> Just 114
 +    "115" -> Just 115
 +    "116" -> Just 116
 +    "117" -> Just 117
 +    "118" -> Just 118
 +    "119" -> Just 119
 +    "120" -> Just 120
 +    "121" -> Just 121
 +    "122" -> Just 122
 +    "123" -> Just 123
 +    "124" -> Just 124
 +    "125" -> Just 125
 +    "126" -> Just 126
 +    "127" -> Just 127
 +    "128" -> Just 128
 +    "129" -> Just 129
 +    "130" -> Just 130
 +    "131" -> Just 131
 +    "132" -> Just 132
 +    "133" -> Just 133
 +    "134" -> Just 134
 +    "135" -> Just 135
 +    "136" -> Just 136
 +    "137" -> Just 137
 +    "138" -> Just 138
 +    "139" -> Just 139
 +    "140" -> Just 140
 +    "141" -> Just 141
 +    "142" -> Just 142
 +    "143" -> Just 143
 +    "144" -> Just 144
 +    "145" -> Just 145
 +    "146" -> Just 146
 +    "147" -> Just 147
 +    "148" -> Just 148
 +    "149" -> Just 149
 +    "150" -> Just 150
 +    "151" -> Just 151
 +    "152" -> Just 152
 +    "153" -> Just 153
 +    "154" -> Just 154
 +    "155" -> Just 155
 +    "156" -> Just 156
 +    "157" -> Just 157
 +    "158" -> Just 158
 +    "159" -> Just 159
 +    "160" -> Just 160
 +    "161" -> Just 161
 +    "162" -> Just 162
 +    "163" -> Just 163
 +    "164" -> Just 164
 +    "165" -> Just 165
 +    "166" -> Just 166
 +    "167" -> Just 167
 +    "168" -> Just 168
 +    "169" -> Just 169
 +    "170" -> Just 170
 +    "171" -> Just 171
 +    "172" -> Just 172
 +    "173" -> Just 173
 +    "174" -> Just 174
 +    "175" -> Just 175
 +    "176" -> Just 176
 +    "177" -> Just 177
 +    "178" -> Just 178
 +    "179" -> Just 179
 +    "180" -> Just 180
 +    "181" -> Just 181
 +    "182" -> Just 182
 +    "183" -> Just 183
 +    "184" -> Just 184
 +    "185" -> Just 185
 +    "186" -> Just 186
 +    "187" -> Just 187
 +    "188" -> Just 188
 +    "189" -> Just 189
 +    "190" -> Just 190
 +    "191" -> Just 191
 +    "192" -> Just 192
 +    "193" -> Just 193
 +    "194" -> Just 194
 +    "195" -> Just 195
 +    "196" -> Just 196
 +    "197" -> Just 197
 +    "198" -> Just 198
 +    "199" -> Just 199
 +    "200" -> Just 200
 +    "201" -> Just 201
 +    "202" -> Just 202
 +    "203" -> Just 203
 +    "204" -> Just 204
 +    "205" -> Just 205
 +    "206" -> Just 206
 +    "207" -> Just 207
 +    "208" -> Just 208
 +    "209" -> Just 209
 +    "210" -> Just 210
 +    "211" -> Just 211
 +    "212" -> Just 212
 +    "213" -> Just 213
 +    "214" -> Just 214
 +    "215" -> Just 215
 +    "216" -> Just 216
 +    "217" -> Just 217
 +    "218" -> Just 218
 +    "219" -> Just 219
 +    "220" -> Just 220
 +    "221" -> Just 221
 +    "222" -> Just 222
 +    "223" -> Just 223
 +    "224" -> Just 224
 +    "225" -> Just 225
 +    "226" -> Just 226
 +    "227" -> Just 227
 +    "228" -> Just 228
 +    "229" -> Just 229
 +    "230" -> Just 230
 +    "231" -> Just 231
 +    "232" -> Just 232
 +    "233" -> Just 233
 +    "234" -> Just 234
 +    "235" -> Just 235
 +    "236" -> Just 236
 +    "237" -> Just 237
 +    "238" -> Just 238
 +    "239" -> Just 239
 +    "240" -> Just 240
 +    "241" -> Just 241
 +    "242" -> Just 242
 +    "243" -> Just 243
 +    "244" -> Just 244
 +    "245" -> Just 245
 +    "246" -> Just 246
 +    "247" -> Just 247
 +    "248" -> Just 248
 +    "249" -> Just 249
 +    "250" -> Just 250
 +    "251" -> Just 251
 +    "252" -> Just 252
 +    "253" -> Just 253
 +    "254" -> Just 254
 +    "255" -> Just 255
 +    "256" -> Just 256
 +    "257" -> Just 257
 +    "258" -> Just 258
 +    "259" -> Just 259
 +    "260" -> Just 260
 +    "261" -> Just 261
 +    "262" -> Just 262
 +    "263" -> Just 263
 +    "264" -> Just 264
 +    "265" -> Just 265
 +    "266" -> Just 266
 +    "267" -> Just 267
 +    "268" -> Just 268
 +    "269" -> Just 269
 +    "270" -> Just 270
 +    "271" -> Just 271
 +    "272" -> Just 272
 +    "273" -> Just 273
 +    "274" -> Just 274
 +    "275" -> Just 275
 +    "276" -> Just 276
 +    "277" -> Just 277
 +    "278" -> Just 278
 +    "279" -> Just 279
 +    "280" -> Just 280
 +    "281" -> Just 281
 +    "282" -> Just 282
 +    "283" -> Just 283
 +    "284" -> Just 284
 +    "285" -> Just 285
 +    "286" -> Just 286
 +    "287" -> Just 287
 +    "288" -> Just 288
 +    "289" -> Just 289
 +    "290" -> Just 290
 +    "291" -> Just 291
 +    "292" -> Just 292
 +    "293" -> Just 293
 +    "294" -> Just 294
 +    "295" -> Just 295
 +    "296" -> Just 296
 +    "297" -> Just 297
 +    "298" -> Just 298
 +    "299" -> Just 299
 +    "300" -> Just 300
 +    "301" -> Just 301
 +    "302" -> Just 302
 +    "303" -> Just 303
 +    "304" -> Just 304
 +    "305" -> Just 305
 +    "306" -> Just 306
 +    "307" -> Just 307
 +    "308" -> Just 308
 +    "309" -> Just 309
 +    "310" -> Just 310
 +    "311" -> Just 311
 +    "312" -> Just 312
 +    "313" -> Just 313
 +    "314" -> Just 314
 +    "315" -> Just 315
 +    "316" -> Just 316
 +    "317" -> Just 317
 +    "318" -> Just 318
 +    "319" -> Just 319
 +    "320" -> Just 320
 +    "321" -> Just 321
 +    "322" -> Just 322
 +    "323" -> Just 323
 +    "324" -> Just 324
 +    "325" -> Just 325
 +    "326" -> Just 326
 +    "327" -> Just 327
 +    "328" -> Just 328
 +    "329" -> Just 329
 +    "330" -> Just 330
 +    "331" -> Just 331
 +    "332" -> Just 332
 +    "333" -> Just 333
 +    "334" -> Just 334
 +    "335" -> Just 335
 +    "336" -> Just 336
 +    "337" -> Just 337
 +    "338" -> Just 338
 +    "339" -> Just 339
 +    "340" -> Just 340
 +    "341" -> Just 341
 +    "342" -> Just 342
 +    "343" -> Just 343
 +    "344" -> Just 344
 +    "345" -> Just 345
 +    "346" -> Just 346
 +    "347" -> Just 347
 +    "348" -> Just 348
 +    "349" -> Just 349
 +    "350" -> Just 350
 +    "351" -> Just 351
 +    "352" -> Just 352
 +    "353" -> Just 353
 +    "354" -> Just 354
 +    "355" -> Just 355
 +    "356" -> Just 356
 +    "357" -> Just 357
 +    "358" -> Just 358
 +    "359" -> Just 359
 +    "360" -> Just 360
 +    "361" -> Just 361
 +    "362" -> Just 362
 +    "363" -> Just 363
 +    "364" -> Just 364
 +    "365" -> Just 365
 +    "366" -> Just 366
 +    "367" -> Just 367
 +    "368" -> Just 368
 +    "369" -> Just 369
 +    "370" -> Just 370
 +    "371" -> Just 371
 +    "372" -> Just 372
 +    "373" -> Just 373
 +    "374" -> Just 374
 +    "375" -> Just 375
 +    "376" -> Just 376
 +    "377" -> Just 377
 +    "378" -> Just 378
 +    "379" -> Just 379
 +    "380" -> Just 380
 +    "381" -> Just 381
 +    "382" -> Just 382
 +    "383" -> Just 383
 +    "384" -> Just 384
 +    "385" -> Just 385
 +    "386" -> Just 386
 +    "387" -> Just 387
 +    "388" -> Just 388
 +    "389" -> Just 389
 +    "390" -> Just 390
 +    "391" -> Just 391
 +    "392" -> Just 392
 +    "393" -> Just 393
 +    "394" -> Just 394
 +    "395" -> Just 395
 +    "396" -> Just 396
 +    "397" -> Just 397
 +    "398" -> Just 398
 +    "399" -> Just 399
 +    "400" -> Just 400
 +    "401" -> Just 401
 +    "402" -> Just 402
 +    "403" -> Just 403
 +    "404" -> Just 404
 +    "405" -> Just 405
 +    "406" -> Just 406
 +    "407" -> Just 407
 +    "408" -> Just 408
 +    "409" -> Just 409
 +    "410" -> Just 410
 +    "411" -> Just 411
 +    "412" -> Just 412
 +    "413" -> Just 413
 +    "414" -> Just 414
 +    "415" -> Just 415
 +    "416" -> Just 416
 +    "417" -> Just 417
 +    "418" -> Just 418
 +    "419" -> Just 419
 +    "420" -> Just 420
 +    "421" -> Just 421
 +    "422" -> Just 422
 +    "423" -> Just 423
 +    "424" -> Just 424
 +    "425" -> Just 425
 +    "426" -> Just 426
 +    "427" -> Just 427
 +    "428" -> Just 428
 +    "429" -> Just 429
 +    "430" -> Just 430
 +    "431" -> Just 431
 +    "432" -> Just 432
 +    "433" -> Just 433
 +    "434" -> Just 434
 +    "435" -> Just 435
 +    "436" -> Just 436
 +    "437" -> Just 437
 +    "438" -> Just 438
 +    "439" -> Just 439
 +    "440" -> Just 440
 +    "441" -> Just 441
 +    "442" -> Just 442
 +    "443" -> Just 443
 +    "444" -> Just 444
 +    "445" -> Just 445
 +    "446" -> Just 446
 +    "447" -> Just 447
 +    "448" -> Just 448
 +    "449" -> Just 449
 +    "450" -> Just 450
 +    "451" -> Just 451
 +    "452" -> Just 452
 +    "453" -> Just 453
 +    "454" -> Just 454
 +    "455" -> Just 455
 +    "456" -> Just 456
 +    "457" -> Just 457
 +    "458" -> Just 458
 +    "459" -> Just 459
 +    "460" -> Just 460
 +    "461" -> Just 461
 +    "462" -> Just 462
 +    "463" -> Just 463
 +    "464" -> Just 464
 +    "465" -> Just 465
 +    "466" -> Just 466
 +    "467" -> Just 467
 +    "468" -> Just 468
 +    "469" -> Just 469
 +    "470" -> Just 470
 +    "471" -> Just 471
 +    "472" -> Just 472
 +    "473" -> Just 473
 +    "474" -> Just 474
 +    "475" -> Just 475
 +    "476" -> Just 476
 +    "477" -> Just 477
 +    "478" -> Just 478
 +    "479" -> Just 479
 +    "480" -> Just 480
 +    "481" -> Just 481
 +    "482" -> Just 482
 +    "483" -> Just 483
 +    "484" -> Just 484
 +    "485" -> Just 485
 +    "486" -> Just 486
 +    "487" -> Just 487
 +    "488" -> Just 488
 +    "489" -> Just 489
 +    "490" -> Just 490
 +    "491" -> Just 491
 +    "492" -> Just 492
 +    "493" -> Just 493
 +    "494" -> Just 494
 +    "495" -> Just 495
 +    "496" -> Just 496
 +    "497" -> Just 497
 +    "498" -> Just 498
 +    "499" -> Just 499
 +    "500" -> Just 500
 +    _ -> Nothing

testsuite/tests/perf/compiler/all.T

@@ -806,3 +806,8 @@ test('interpreter_steplocal',
       ],
       ghci_script,
       ['interpreter_steplocal.script'])
++
 +test ('T26425',
 +      [ collect_compiler_stats('all',5) ],
 +      compile,
 +      ['-O'])