-- * Configuration of the core-to-core passes
CoreToDo(..),
SimplifierMode(..),
- SimplifierSwitch(..),
FloatOutSwitches(..),
getCoreToDo, dumpSimplPhase,
import CoreLint ( lintCoreBindings )
import PrelNames ( iNTERACTIVE )
import HscTypes
-import Module ( PackageId, Module )
+import Module ( Module )
import DynFlags
import StaticFlags
import Rules ( RuleBase )
-import BasicTypes ( CompilerPhase )
+import BasicTypes ( CompilerPhase(..) )
import Annotations
import Id ( Id )
import Maybes
import UniqSupply
import UniqFM ( UniqFM, mapUFM, filterUFM )
+import MonadUtils
import Util ( split )
import Data.List ( intersperse )
showLintWarnings :: CoreToDo -> Bool
-- Disable Lint warnings on the first simplifier pass, because
-- there may be some INLINE knots still tied, which is tiresomely noisy
-showLintWarnings (CoreDoSimplify (SimplGently {}) _ _) = False
-showLintWarnings _ = True
+showLintWarnings (CoreDoSimplify _ (SimplMode { sm_phase = InitialPhase })) = False
+showLintWarnings _ = True
\end{code}
-- as many times as you like.
= CoreDoSimplify -- The core-to-core simplifier.
+ Int -- Max iterations
SimplifierMode
- Int -- Max iterations
- [SimplifierSwitch] -- Each run of the simplifier can take a different
- -- set of simplifier-specific flags.
+
| CoreDoFloatInwards
| CoreDoFloatOutwards FloatOutSwitches
| CoreLiberateCase
| CoreCSE
| CoreDoRuleCheck CompilerPhase String -- Check for non-application of rules
-- matching this string
- | CoreDoVectorisation PackageId
+ | CoreDoVectorisation
| CoreDoNothing -- Useful when building up
| CoreDoPasses [CoreToDo] -- lists of these things
coreDumpFlag CoreDoSpecialising = Just Opt_D_dump_spec
coreDumpFlag CoreDoSpecConstr = Just Opt_D_dump_spec
coreDumpFlag CoreCSE = Just Opt_D_dump_cse
-coreDumpFlag (CoreDoVectorisation {}) = Just Opt_D_dump_vect
-coreDumpFlag CoreDesugar = Just Opt_D_dump_ds
-coreDumpFlag CoreTidy = Just Opt_D_dump_simpl
-coreDumpFlag CorePrep = Just Opt_D_dump_prep
+coreDumpFlag CoreDoVectorisation = Just Opt_D_dump_vect
+coreDumpFlag CoreDesugar = Just Opt_D_dump_ds
+coreDumpFlag CoreTidy = Just Opt_D_dump_simpl
+coreDumpFlag CorePrep = Just Opt_D_dump_prep
coreDumpFlag CoreDoPrintCore = Nothing
coreDumpFlag (CoreDoRuleCheck {}) = Nothing
coreDumpFlag (CoreDoPasses {}) = Nothing
instance Outputable CoreToDo where
- ppr (CoreDoSimplify md n _) = ptext (sLit "Simplifier")
- <+> ppr md
+ ppr (CoreDoSimplify n md) = ptext (sLit "Simplifier")
+ <+> ppr md
<+> ptext (sLit "max-iterations=") <> int n
ppr CoreDoFloatInwards = ptext (sLit "Float inwards")
ppr (CoreDoFloatOutwards f) = ptext (sLit "Float out") <> parens (ppr f)
ppr CoreDoSpecialising = ptext (sLit "Specialise")
ppr CoreDoSpecConstr = ptext (sLit "SpecConstr")
ppr CoreCSE = ptext (sLit "Common sub-expression")
- ppr (CoreDoVectorisation {}) = ptext (sLit "Vectorisation")
- ppr CoreDesugar = ptext (sLit "Desugar")
- ppr CoreTidy = ptext (sLit "Tidy Core")
+ ppr CoreDoVectorisation = ptext (sLit "Vectorisation")
+ ppr CoreDesugar = ptext (sLit "Desugar")
+ ppr CoreTidy = ptext (sLit "Tidy Core")
ppr CorePrep = ptext (sLit "CorePrep")
ppr CoreDoPrintCore = ptext (sLit "Print core")
ppr (CoreDoRuleCheck {}) = ptext (sLit "Rule check")
\begin{code}
data SimplifierMode -- See comments in SimplMonad
- = SimplGently
- { sm_rules :: Bool -- Whether RULES are enabled
- , sm_inline :: Bool } -- Whether inlining is enabled
-
- | SimplPhase
- { sm_num :: Int -- Phase number; counts downward so 0 is last phase
- , sm_names :: [String] } -- Name(s) of the phase
+ = SimplMode
+ { sm_names :: [String] -- Name(s) of the phase
+ , sm_phase :: CompilerPhase
+ , sm_rules :: Bool -- Whether RULES are enabled
+ , sm_inline :: Bool -- Whether inlining is enabled
+ , sm_case_case :: Bool -- Whether case-of-case is enabled
+ , sm_eta_expand :: Bool -- Whether eta-expansion is enabled
+ }
instance Outputable SimplifierMode where
- ppr (SimplPhase { sm_num = n, sm_names = ss })
- = ptext (sLit "Phase") <+> int n <+> brackets (text (concat $ intersperse "," ss))
- ppr (SimplGently { sm_rules = r, sm_inline = i })
- = ptext (sLit "gentle") <>
- brackets (pp_flag r (sLit "rules") <> comma <>
- pp_flag i (sLit "inline"))
+ ppr (SimplMode { sm_phase = p, sm_names = ss
+ , sm_rules = r, sm_inline = i
+ , sm_eta_expand = eta, sm_case_case = cc })
+ = ptext (sLit "SimplMode") <+> braces (
+ sep [ ptext (sLit "Phase =") <+> ppr p <+>
+ brackets (text (concat $ intersperse "," ss)) <> comma
+ , pp_flag i (sLit "inline") <> comma
+ , pp_flag r (sLit "rules") <> comma
+ , pp_flag eta (sLit "eta-expand") <> comma
+ , pp_flag cc (sLit "case-of-case") ])
where
pp_flag f s = ppUnless f (ptext (sLit "no")) <+> ptext s
-
-data SimplifierSwitch
- = NoCaseOfCase
\end{code}
\begin{code}
data FloatOutSwitches = FloatOutSwitches {
- floatOutLambdas :: Bool, -- ^ True <=> float lambdas to top level
- floatOutConstants :: Bool, -- ^ True <=> float constants to top level,
- -- even if they do not escape a lambda
- floatOutPartialApplications :: Bool -- ^ True <=> float out partial applications
+ floatOutLambdas :: Maybe Int, -- ^ Just n <=> float lambdas to top level, if
+ -- doing so will abstract over n or fewer
+ -- value variables
+ -- Nothing <=> float all lambdas to top level,
+ -- regardless of how many free variables
+ -- Just 0 is the vanilla case: float a lambda
+ -- iff it has no free vars
+
+ floatOutConstants :: Bool, -- ^ True <=> float constants to top level,
+ -- even if they do not escape a lambda
+ floatOutPartialApplications :: Bool -- ^ True <=> float out partial applications
-- based on arity information.
- }
+ }
instance Outputable FloatOutSwitches where
ppr = pprFloatOutSwitches
pprFloatOutSwitches :: FloatOutSwitches -> SDoc
-pprFloatOutSwitches sw = pp_not (floatOutLambdas sw) <+> text "lambdas" <> comma
- <+> pp_not (floatOutConstants sw) <+> text "constants"
- where
- pp_not True = empty
- pp_not False = text "not"
-
--- | Switches that specify the minimum amount of floating out
--- gentleFloatOutSwitches :: FloatOutSwitches
--- gentleFloatOutSwitches = FloatOutSwitches False False
+pprFloatOutSwitches sw
+ = ptext (sLit "FOS") <+> (braces $
+ sep $ punctuate comma $
+ [ ptext (sLit "Lam =") <+> ppr (floatOutLambdas sw)
+ , ptext (sLit "Consts =") <+> ppr (floatOutConstants sw)
+ , ptext (sLit "PAPs =") <+> ppr (floatOutPartialApplications sw) ])
\end{code}
getCoreToDo dflags
= core_todo
where
- opt_level = optLevel dflags
- phases = simplPhases dflags
+ opt_level = optLevel dflags
+ phases = simplPhases dflags
max_iter = maxSimplIterations dflags
- strictness = dopt Opt_Strictness dflags
- full_laziness = dopt Opt_FullLaziness dflags
- do_specialise = dopt Opt_Specialise dflags
- do_float_in = dopt Opt_FloatIn dflags
- cse = dopt Opt_CSE dflags
- spec_constr = dopt Opt_SpecConstr dflags
- liberate_case = dopt Opt_LiberateCase dflags
- rule_check = ruleCheck dflags
+ rule_check = ruleCheck dflags
+ strictness = dopt Opt_Strictness dflags
+ full_laziness = dopt Opt_FullLaziness dflags
+ do_specialise = dopt Opt_Specialise dflags
+ do_float_in = dopt Opt_FloatIn dflags
+ cse = dopt Opt_CSE dflags
+ spec_constr = dopt Opt_SpecConstr dflags
+ liberate_case = dopt Opt_LiberateCase dflags
static_args = dopt Opt_StaticArgumentTransformation dflags
+ rules_on = dopt Opt_EnableRewriteRules dflags
+ eta_expand_on = dopt Opt_DoLambdaEtaExpansion dflags
maybe_rule_check phase = runMaybe rule_check (CoreDoRuleCheck phase)
maybe_strictness_before phase
= runWhen (phase `elem` strictnessBefore dflags) CoreDoStrictness
+ base_mode = SimplMode { sm_phase = panic "base_mode"
+ , sm_names = []
+ , sm_rules = rules_on
+ , sm_eta_expand = eta_expand_on
+ , sm_inline = True
+ , sm_case_case = True }
+
simpl_phase phase names iter
= CoreDoPasses
- [ maybe_strictness_before phase
- , CoreDoSimplify (SimplPhase phase names)
- iter []
- , maybe_rule_check phase
- ]
+ $ [ maybe_strictness_before phase
+ , CoreDoSimplify iter
+ (base_mode { sm_phase = Phase phase
+ , sm_names = names })
+
+ , maybe_rule_check (Phase phase) ]
+
+ -- Vectorisation can introduce a fair few common sub expressions involving
+ -- DPH primitives. For example, see the Reverse test from dph-examples.
+ -- We need to eliminate these common sub expressions before their definitions
+ -- are inlined in phase 2. The CSE introduces lots of v1 = v2 bindings,
+ -- so we also run simpl_gently to inline them.
+ ++ (if dopt Opt_Vectorise dflags && phase == 3
+ then [CoreCSE, simpl_gently]
+ else [])
vectorisation
- = runWhen (dopt Opt_Vectorise dflags)
- $ CoreDoPasses [ simpl_gently, CoreDoVectorisation (dphPackage dflags) ]
-
+ = runWhen (dopt Opt_Vectorise dflags) $
+ CoreDoPasses [ simpl_gently, CoreDoVectorisation ]
-- By default, we have 2 phases before phase 0.
-- strictness in the function sumcode' if augment is not inlined
-- before strictness analysis runs
simpl_phases = CoreDoPasses [ simpl_phase phase ["main"] max_iter
- | phase <- [phases, phases-1 .. 1] ]
+ | phase <- [phases, phases-1 .. 1] ]
-- initial simplify: mk specialiser happy: minimum effort please
- simpl_gently = CoreDoSimplify
- (SimplGently { sm_rules = True, sm_inline = False })
- -- See Note [Gentle mode] and
- -- Note [RULEs enabled in SimplGently] in SimplUtils
- max_iter
- [
-
-
- NoCaseOfCase -- Don't do case-of-case transformations.
- -- This makes full laziness work better
- ]
+ simpl_gently = CoreDoSimplify max_iter
+ (base_mode { sm_phase = InitialPhase
+ , sm_names = ["Gentle"]
+ , sm_rules = rules_on -- Note [RULEs enabled in SimplGently]
+ , sm_inline = False
+ , sm_case_case = False })
+ -- Don't do case-of-case transformations.
+ -- This makes full laziness work better
core_todo =
if opt_level == 0 then
runWhen full_laziness $
CoreDoFloatOutwards FloatOutSwitches {
- floatOutLambdas = False,
+ floatOutLambdas = Just 0,
floatOutConstants = True,
floatOutPartialApplications = False },
-- Was: gentleFloatOutSwitches
runWhen full_laziness $
CoreDoFloatOutwards FloatOutSwitches {
- floatOutLambdas = False,
+ floatOutLambdas = floatLamArgs dflags,
floatOutConstants = True,
floatOutPartialApplications = True },
-- nofib/spectral/hartel/wang doubles in speed if you
runWhen do_float_in CoreDoFloatInwards,
- maybe_rule_check 0,
+ maybe_rule_check (Phase 0),
-- Case-liberation for -O2. This should be after
-- strictness analysis and the simplification which follows it.
runWhen spec_constr CoreDoSpecConstr,
- maybe_rule_check 0,
+ maybe_rule_check (Phase 0),
-- Final clean-up simplification:
simpl_phase 0 ["final"] max_iter
_ -> phase_name s
phase_num :: Int -> Bool
- phase_num n = case mode of
- SimplPhase k _ -> n == k
- _ -> False
+ phase_num n = case sm_phase mode of
+ Phase k -> n == k
+ _ -> False
phase_name :: String -> Bool
- phase_name s = case mode of
- SimplGently {} -> s == "gentle"
- SimplPhase { sm_names = ss } -> s `elem` ss
+ phase_name s = s `elem` sm_names mode
\end{code}
+Note [RULEs enabled in SimplGently]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+RULES are enabled when doing "gentle" simplification. Two reasons:
+
+ * We really want the class-op cancellation to happen:
+ op (df d1 d2) --> $cop3 d1 d2
+ because this breaks the mutual recursion between 'op' and 'df'
+
+ * I wanted the RULE
+ lift String ===> ...
+ to work in Template Haskell when simplifying
+ splices, so we get simpler code for literal strings
+
+But watch out: list fusion can prevent floating. So use phase control
+to switch off those rules until after floating.
+
+
%************************************************************************
%* *
Counting and logging