[Git][ghc/ghc][wip/T21851] Fire RULES in the Specialiser
Simon Peyton Jones (@simonpj)
gitlab at gitlab.haskell.org
Tue Oct 11 14:13:54 UTC 2022
Simon Peyton Jones pushed to branch wip/T21851 at Glasgow Haskell Compiler / GHC
Commits:
b3b1ddd8 by Simon Peyton Jones at 2022-10-11T15:14:19+01:00
Fire RULES in the Specialiser
The Specialiser has, for some time, fires class-op RULES in the
specialiser itself: see
Note [Specialisation modulo dictionary selectors]
This MR beefs it up a bit, so that it fires /all/ RULES in the
specialiser, not just class-op rules. See
Note [Fire rules in the specialiser]
The result is a bit more specialisation; see test
simplCore/should_compile/T21851_2
This pushed me into a bit of refactoring. I made a new data types
GHC.Core.Rules.RuleEnv, which combines
- the several source of rules (local, home-package, external)
- the orphan-module dependencies
in a single record for `getRules` to consult. That drove a bunch of
follow-on refactoring, including allowing me to remove
cr_visible_orphan_mods from the CoreReader data type.
I moved some of the RuleBase/RuleEnv stuff into GHC.Core.Rule.
- - - - -
17 changed files:
- compiler/GHC/Core.hs
- compiler/GHC/Core/InstEnv.hs
- compiler/GHC/Core/Opt/Monad.hs
- compiler/GHC/Core/Opt/Pipeline.hs
- compiler/GHC/Core/Opt/Simplify.hs
- compiler/GHC/Core/Opt/Simplify/Monad.hs
- compiler/GHC/Core/Opt/Simplify/Utils.hs
- compiler/GHC/Core/Opt/Specialise.hs
- compiler/GHC/Core/Rules.hs
- compiler/GHC/Driver/Config/Core/Opt/Simplify.hs
- compiler/GHC/Unit/External.hs
- libraries/base/GHC/Real.hs
- testsuite/tests/simplCore/should_compile/T21851.stderr
- + testsuite/tests/simplCore/should_compile/T21851_2.hs
- + testsuite/tests/simplCore/should_compile/T21851_2.stderr
- + testsuite/tests/simplCore/should_compile/T21851_2a.hs
- testsuite/tests/simplCore/should_compile/all.T
Changes:
=====================================
compiler/GHC/Core.hs
=====================================
@@ -84,9 +84,8 @@ module GHC.Core (
IsOrphan(..), isOrphan, notOrphan, chooseOrphanAnchor,
-- * Core rule data types
- CoreRule(..), RuleBase,
- RuleName, RuleFun, IdUnfoldingFun, InScopeEnv,
- RuleEnv(..), RuleOpts, mkRuleEnv, emptyRuleEnv,
+ CoreRule(..),
+ RuleName, RuleFun, IdUnfoldingFun, InScopeEnv, RuleOpts,
-- ** Operations on 'CoreRule's
ruleArity, ruleName, ruleIdName, ruleActivation,
@@ -104,7 +103,6 @@ import GHC.Core.Coercion
import GHC.Core.Rules.Config ( RuleOpts )
import GHC.Types.Name
import GHC.Types.Name.Set
-import GHC.Types.Name.Env( NameEnv )
import GHC.Types.Literal
import GHC.Types.Tickish
import GHC.Core.DataCon
@@ -1061,6 +1059,12 @@ has two major consequences
M. But it's painful, because it means we need to keep track of all
the orphan modules below us.
+ * The "visible orphan modules" are all the orphan module in the transitive
+ closure of the imports of this module.
+
+ * During instance lookup, we filter orphan instances depending on
+ whether or not the instance is in a visible orphan module.
+
* A non-orphan is not finger-printed separately. Instead, for
fingerprinting purposes it is treated as part of the entity it
mentions on the LHS. For example
@@ -1075,12 +1079,20 @@ has two major consequences
Orphan-hood is computed
* For class instances:
- when we make a ClsInst
- (because it is needed during instance lookup)
+ when we make a ClsInst in GHC.Core.InstEnv.mkLocalInstance
+ (because it is needed during instance lookup)
+ See Note [When exactly is an instance decl an orphan?]
+ in GHC.Core.InstEnv
+
+ * For rules
+ when we generate a CoreRule (GHC.Core.Rules.mkRule)
+
+ * For family instances:
+ when we generate an IfaceFamInst (GHC.Iface.Make.instanceToIfaceInst)
+
+Orphan-hood is persisted into interface files, in ClsInst, FamInst,
+and CoreRules.
- * For rules and family instances:
- when we generate an IfaceRule (GHC.Iface.Make.coreRuleToIfaceRule)
- or IfaceFamInst (GHC.Iface.Make.instanceToIfaceInst)
-}
{-
@@ -1095,49 +1107,6 @@ GHC.Core.FVs, GHC.Core.Subst, GHC.Core.Ppr, GHC.Core.Tidy also inspect the
representation.
-}
--- | Gathers a collection of 'CoreRule's. Maps (the name of) an 'Id' to its rules
-type RuleBase = NameEnv [CoreRule]
- -- The rules are unordered;
- -- we sort out any overlaps on lookup
-
--- | A full rule environment which we can apply rules from. Like a 'RuleBase',
--- but it also includes the set of visible orphans we use to filter out orphan
--- rules which are not visible (even though we can see them...)
-data RuleEnv
- = RuleEnv { re_base :: [RuleBase] -- See Note [Why re_base is a list]
- , re_visible_orphs :: ModuleSet
- }
-
-mkRuleEnv :: RuleBase -> [Module] -> RuleEnv
-mkRuleEnv rules vis_orphs = RuleEnv [rules] (mkModuleSet vis_orphs)
-
-emptyRuleEnv :: RuleEnv
-emptyRuleEnv = RuleEnv [] emptyModuleSet
-
-{-
-Note [Why re_base is a list]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-In Note [Overall plumbing for rules], it is explained that the final
-RuleBase which we must consider is combined from 4 different sources.
-
-During simplifier runs, the fourth source of rules is constantly being updated
-as new interfaces are loaded into the EPS. Therefore just before we check to see
-if any rules match we get the EPS RuleBase and combine it with the existing RuleBase
-and then perform exactly 1 lookup into the new map.
-
-It is more efficient to avoid combining the environments and store the uncombined
-environments as we can instead perform 1 lookup into each environment and then combine
-the results.
-
-Essentially we use the identity:
-
-> lookupNameEnv n (plusNameEnv_C (++) rb1 rb2)
-> = lookupNameEnv n rb1 ++ lookupNameEnv n rb2
-
-The latter being more efficient as we don't construct an intermediate
-map.
--}
-- | A 'CoreRule' is:
--
=====================================
compiler/GHC/Core/InstEnv.hs
=====================================
@@ -319,7 +319,9 @@ mkImportedInstance cls_nm mb_tcs dfun_name dfun oflag orphan
{-
Note [When exactly is an instance decl an orphan?]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- (see GHC.Iface.Make.instanceToIfaceInst, which implements this)
+(See GHC.Iface.Make.instanceToIfaceInst, which implements this.)
+See Note [Orphans] in GHC.Core
+
Roughly speaking, an instance is an orphan if its head (after the =>)
mentions nothing defined in this module.
=====================================
compiler/GHC/Core/Opt/Monad.hs
=====================================
@@ -19,10 +19,10 @@ module GHC.Core.Opt.Monad (
-- ** Reading from the monad
getHscEnv, getModule,
- getRuleBase, getExternalRuleBase,
+ initRuleEnv, getExternalRuleBase,
getDynFlags, getPackageFamInstEnv,
getInteractiveContext,
- getVisibleOrphanMods, getUniqMask,
+ getUniqMask,
getPrintUnqualified, getSrcSpanM,
-- ** Writing to the monad
@@ -45,7 +45,7 @@ import GHC.Prelude hiding ( read )
import GHC.Driver.Session
import GHC.Driver.Env
-import GHC.Core
+import GHC.Core.Rules ( RuleBase, RuleEnv, mkRuleEnv )
import GHC.Core.Opt.Stats ( SimplCount, zeroSimplCount, plusSimplCount )
import GHC.Types.Annotations
@@ -113,12 +113,11 @@ pprFloatOutSwitches sw
data CoreReader = CoreReader {
cr_hsc_env :: HscEnv,
- cr_rule_base :: RuleBase,
+ cr_rule_base :: RuleBase, -- Home package table rules
cr_module :: Module,
cr_print_unqual :: PrintUnqualified,
cr_loc :: SrcSpan, -- Use this for log/error messages so they
-- are at least tagged with the right source file
- cr_visible_orphan_mods :: !ModuleSet,
cr_uniq_mask :: !Char -- Mask for creating unique values
}
@@ -180,19 +179,17 @@ runCoreM :: HscEnv
-> RuleBase
-> Char -- ^ Mask
-> Module
- -> ModuleSet
-> PrintUnqualified
-> SrcSpan
-> CoreM a
-> IO (a, SimplCount)
-runCoreM hsc_env rule_base mask mod orph_imps print_unqual loc m
+runCoreM hsc_env rule_base mask mod print_unqual loc m
= liftM extract $ runIOEnv reader $ unCoreM m
where
reader = CoreReader {
cr_hsc_env = hsc_env,
cr_rule_base = rule_base,
cr_module = mod,
- cr_visible_orphan_mods = orph_imps,
cr_print_unqual = print_unqual,
cr_loc = loc,
cr_uniq_mask = mask
@@ -244,15 +241,18 @@ liftIOWithCount what = liftIO what >>= (\(count, x) -> addSimplCount count >> re
getHscEnv :: CoreM HscEnv
getHscEnv = read cr_hsc_env
-getRuleBase :: CoreM RuleBase
-getRuleBase = read cr_rule_base
+getHomeRuleBase :: CoreM RuleBase
+getHomeRuleBase = read cr_rule_base
+
+initRuleEnv :: ModGuts -> CoreM RuleEnv
+initRuleEnv guts
+ = do { hpt_rules <- getHomeRuleBase
+ ; eps_rules <- getExternalRuleBase
+ ; return (mkRuleEnv guts eps_rules hpt_rules) }
getExternalRuleBase :: CoreM RuleBase
getExternalRuleBase = eps_rule_base <$> get_eps
-getVisibleOrphanMods :: CoreM ModuleSet
-getVisibleOrphanMods = read cr_visible_orphan_mods
-
getPrintUnqualified :: CoreM PrintUnqualified
getPrintUnqualified = read cr_print_unqual
=====================================
compiler/GHC/Core/Opt/Pipeline.hs
=====================================
@@ -22,7 +22,7 @@ import GHC.Platform.Ways ( hasWay, Way(WayProf) )
import GHC.Core
import GHC.Core.Opt.CSE ( cseProgram )
-import GHC.Core.Rules ( mkRuleBase, ruleCheckProgram, getRules )
+import GHC.Core.Rules ( RuleBase, mkRuleBase, ruleCheckProgram, getRules )
import GHC.Core.Ppr ( pprCoreBindings )
import GHC.Core.Utils ( dumpIdInfoOfProgram )
import GHC.Core.Lint ( lintAnnots )
@@ -52,9 +52,7 @@ import GHC.Utils.Logger as Logger
import GHC.Utils.Outputable
import GHC.Utils.Panic
-import GHC.Unit.Module.Env
import GHC.Unit.Module.ModGuts
-import GHC.Unit.Module.Deps
import GHC.Types.Id.Info
import GHC.Types.Basic
@@ -77,14 +75,12 @@ import GHC.Unit.Module
core2core :: HscEnv -> ModGuts -> IO ModGuts
core2core hsc_env guts@(ModGuts { mg_module = mod
, mg_loc = loc
- , mg_deps = deps
, mg_rdr_env = rdr_env })
= do { let builtin_passes = getCoreToDo dflags hpt_rule_base extra_vars
- orph_mods = mkModuleSet (mod : dep_orphs deps)
uniq_mask = 's'
- ;
+
; (guts2, stats) <- runCoreM hsc_env hpt_rule_base uniq_mask mod
- orph_mods print_unqual loc $
+ print_unqual loc $
do { hsc_env' <- getHscEnv
; all_passes <- withPlugins (hsc_plugins hsc_env')
installCoreToDos
@@ -120,7 +116,8 @@ core2core hsc_env guts@(ModGuts { mg_module = mod
-}
getCoreToDo :: DynFlags -> RuleBase -> [Var] -> [CoreToDo]
-getCoreToDo dflags rule_base extra_vars
+-- This function builds the pipeline of optimisations
+getCoreToDo dflags hpt_rule_base extra_vars
= flatten_todos core_todo
where
phases = simplPhases dflags
@@ -158,7 +155,7 @@ getCoreToDo dflags rule_base extra_vars
= CoreDoPasses
$ [ maybe_strictness_before phase
, CoreDoSimplify $ initSimplifyOpts dflags extra_vars iter
- (initSimplMode dflags phase name) rule_base
+ (initSimplMode dflags phase name) hpt_rule_base
, maybe_rule_check phase ]
-- Run GHC's internal simplification phase, after all rules have run.
@@ -169,7 +166,7 @@ getCoreToDo dflags rule_base extra_vars
-- See Note [Inline in InitialPhase]
-- See Note [RULEs enabled in InitialPhase]
simpl_gently = CoreDoSimplify $ initSimplifyOpts dflags extra_vars max_iter
- (initGentleSimplMode dflags) rule_base
+ (initGentleSimplMode dflags) hpt_rule_base
dmd_cpr_ww = if ww_on then [CoreDoDemand True,CoreDoCpr,CoreDoWorkerWrapper]
else [CoreDoDemand False] -- NB: No CPR! See Note [Don't change boxity without worker/wrapper]
@@ -547,11 +544,9 @@ ruleCheckPass current_phase pat guts = do
logger <- getLogger
withTiming logger (text "RuleCheck"<+>brackets (ppr $ mg_module guts))
(const ()) $ do
- rb <- getRuleBase
- vis_orphs <- getVisibleOrphanMods
- let rule_fn fn = getRules (RuleEnv [rb] vis_orphs) fn
- ++ (mg_rules guts)
- let ropts = initRuleOpts dflags
+ rule_env <- initRuleEnv guts
+ let rule_fn fn = getRules rule_env fn
+ ropts = initRuleOpts dflags
liftIO $ logDumpMsg logger "Rule check"
(ruleCheckProgram ropts current_phase pat
rule_fn (mg_binds guts))
=====================================
compiler/GHC/Core/Opt/Simplify.hs
=====================================
@@ -10,7 +10,7 @@ import GHC.Prelude
import GHC.Driver.Flags
import GHC.Core
-import GHC.Core.Rules ( extendRuleBaseList, extendRuleEnv, addRuleInfo )
+import GHC.Core.Rules
import GHC.Core.Ppr ( pprCoreBindings, pprCoreExpr )
import GHC.Core.Opt.OccurAnal ( occurAnalysePgm, occurAnalyseExpr )
import GHC.Core.Stats ( coreBindsSize, coreBindsStats, exprSize )
@@ -32,7 +32,6 @@ import GHC.Utils.Trace
import GHC.Unit.Env ( UnitEnv, ueEPS )
import GHC.Unit.External
import GHC.Unit.Module.ModGuts
-import GHC.Unit.Module.Deps
import GHC.Types.Id
import GHC.Types.Id.Info
@@ -82,7 +81,7 @@ simplifyExpr logger euc opts expr
simpl_env = mkSimplEnv (se_mode opts) fam_envs
top_env_cfg = se_top_env_cfg opts
read_eps_rules = eps_rule_base <$> eucEPS euc
- read_ruleenv = extendRuleEnv emptyRuleEnv <$> read_eps_rules
+ read_ruleenv = updExternalPackageRules emptyRuleEnv <$> read_eps_rules
; let sz = exprSize expr
@@ -133,11 +132,11 @@ simplExprGently env expr = do
-- The values of this datatype are /only/ driven by the demands of that function.
data SimplifyOpts = SimplifyOpts
{ so_dump_core_sizes :: !Bool
- , so_iterations :: !Int
- , so_mode :: !SimplMode
+ , so_iterations :: !Int
+ , so_mode :: !SimplMode
, so_pass_result_cfg :: !(Maybe LintPassResultConfig)
- , so_rule_base :: !RuleBase
- , so_top_env_cfg :: !TopEnvConfig
+ , so_hpt_rules :: !RuleBase
+ , so_top_env_cfg :: !TopEnvConfig
}
simplifyPgm :: Logger
@@ -149,11 +148,10 @@ simplifyPgm :: Logger
simplifyPgm logger unit_env opts
guts@(ModGuts { mg_module = this_mod
, mg_rdr_env = rdr_env
- , mg_deps = deps
- , mg_binds = binds, mg_rules = rules
+ , mg_binds = binds, mg_rules = local_rules
, mg_fam_inst_env = fam_inst_env })
= do { (termination_msg, it_count, counts_out, guts')
- <- do_iteration 1 [] binds rules
+ <- do_iteration 1 [] binds local_rules
; when (logHasDumpFlag logger Opt_D_verbose_core2core
&& logHasDumpFlag logger Opt_D_dump_simpl_stats) $
@@ -170,7 +168,6 @@ simplifyPgm logger unit_env opts
dump_core_sizes = so_dump_core_sizes opts
mode = so_mode opts
max_iterations = so_iterations opts
- hpt_rule_base = so_rule_base opts
top_env_cfg = so_top_env_cfg opts
print_unqual = mkPrintUnqualified unit_env rdr_env
active_rule = activeRule mode
@@ -179,13 +176,18 @@ simplifyPgm logger unit_env opts
-- the old bindings are retained until the end of all simplifier iterations
!guts_no_binds = guts { mg_binds = [], mg_rules = [] }
+ hpt_rule_env :: RuleEnv
+ hpt_rule_env = mkRuleEnv guts emptyRuleBase (so_hpt_rules opts)
+ -- emptyRuleBase: no EPS rules yet; we will update
+ -- them on each iteration to pick up the most up to date set
+
do_iteration :: Int -- Counts iterations
-> [SimplCount] -- Counts from earlier iterations, reversed
- -> CoreProgram -- Bindings in
- -> [CoreRule] -- and orphan rules
+ -> CoreProgram -- Bindings
+ -> [CoreRule] -- Local rules for imported Ids
-> IO (String, Int, SimplCount, ModGuts)
- do_iteration iteration_no counts_so_far binds rules
+ do_iteration iteration_no counts_so_far binds local_rules
-- iteration_no is the number of the iteration we are
-- about to begin, with '1' for the first
| iteration_no > max_iterations -- Stop if we've run out of iterations
@@ -201,7 +203,7 @@ simplifyPgm logger unit_env opts
-- number of iterations we actually completed
return ( "Simplifier baled out", iteration_no - 1
, totalise counts_so_far
- , guts_no_binds { mg_binds = binds, mg_rules = rules } )
+ , guts_no_binds { mg_binds = binds, mg_rules = local_rules } )
-- Try and force thunks off the binds; significantly reduces
-- space usage, especially with -O. JRS, 000620.
@@ -210,8 +212,8 @@ simplifyPgm logger unit_env opts
= do {
-- Occurrence analysis
let { tagged_binds = {-# SCC "OccAnal" #-}
- occurAnalysePgm this_mod active_unf active_rule rules
- binds
+ occurAnalysePgm this_mod active_unf active_rule
+ local_rules binds
} ;
Logger.putDumpFileMaybe logger Opt_D_dump_occur_anal "Occurrence analysis"
FormatCore
@@ -222,24 +224,29 @@ simplifyPgm logger unit_env opts
-- poke on IdInfo thunks, which in turn brings in new rules
-- behind the scenes. Otherwise there's a danger we'll simply
-- miss the rules for Ids hidden inside imported inlinings
- -- Hence just before attempting to match rules we read on the EPS
- -- value and then combine it when the existing rule base.
+ -- Hence just before attempting to match a rule we read the EPS
+ -- value (via read_rule_env) and then combine it with the existing rule base.
-- See `GHC.Core.Opt.Simplify.Monad.getSimplRules`.
- eps <- ueEPS unit_env ;
- let { -- Forcing this value to avoid unnessecary allocations.
+ eps <- ueEPS unit_env ;
+ let { -- base_rule_env contains
+ -- (a) home package rules, fixed across all iterations
+ -- (b) local rules (substituted) from `local_rules` arg to do_iteration
+ -- Forcing base_rule_env to avoid unnecessary allocations.
-- Not doing so results in +25.6% allocations of LargeRecord.
- ; !rule_base = extendRuleBaseList hpt_rule_base rules
- ; vis_orphs = this_mod : dep_orphs deps
- ; base_ruleenv = mkRuleEnv rule_base vis_orphs
+ ; !base_rule_env = updLocalRules hpt_rule_env local_rules
+
+ ; read_eps_rules :: IO PackageRuleBase
; read_eps_rules = eps_rule_base <$> ueEPS unit_env
- ; read_ruleenv = extendRuleEnv base_ruleenv <$> read_eps_rules
+
+ ; read_rule_env :: IO RuleEnv
+ ; read_rule_env = updExternalPackageRules base_rule_env <$> read_eps_rules
; fam_envs = (eps_fam_inst_env eps, fam_inst_env)
; simpl_env = mkSimplEnv mode fam_envs } ;
-- Simplify the program
((binds1, rules1), counts1) <-
- initSmpl logger read_ruleenv top_env_cfg sz $
+ initSmpl logger read_rule_env top_env_cfg sz $
do { (floats, env1) <- {-# SCC "SimplTopBinds" #-}
simplTopBinds simpl_env tagged_binds
@@ -247,7 +254,7 @@ simplifyPgm logger unit_env opts
-- for imported Ids. Eg RULE map my_f = blah
-- If we have a substitution my_f :-> other_f, we'd better
-- apply it to the rule to, or it'll never match
- ; rules1 <- simplImpRules env1 rules
+ ; rules1 <- simplImpRules env1 local_rules
; return (getTopFloatBinds floats, rules1) } ;
=====================================
compiler/GHC/Core/Opt/Simplify/Monad.hs
=====================================
@@ -27,8 +27,8 @@ import GHC.Types.Name ( mkSystemVarName )
import GHC.Types.Id ( Id, mkSysLocalOrCoVarM )
import GHC.Types.Id.Info ( IdDetails(..), vanillaIdInfo, setArityInfo )
import GHC.Core.Type ( Type, Mult )
-import GHC.Core ( RuleEnv(..) )
import GHC.Core.Opt.Stats
+import GHC.Core.Rules
import GHC.Core.Utils ( mkLamTypes )
import GHC.Types.Unique.Supply
import GHC.Driver.Flags
=====================================
compiler/GHC/Core/Opt/Simplify/Utils.hs
=====================================
@@ -53,7 +53,7 @@ import GHC.Core.Ppr
import GHC.Core.TyCo.Ppr ( pprParendType )
import GHC.Core.FVs
import GHC.Core.Utils
-import GHC.Core.Rules( getRules )
+import GHC.Core.Rules( RuleEnv, getRules )
import GHC.Core.Opt.Arity
import GHC.Core.Unfold
import GHC.Core.Unfold.Make
=====================================
compiler/GHC/Core/Opt/Specialise.hs
=====================================
@@ -19,6 +19,7 @@ import GHC.Tc.Utils.TcType hiding( substTy )
import GHC.Core.Type hiding( substTy, extendTvSubstList, zapSubst )
import GHC.Core.Multiplicity
+import GHC.Core.SimpleOpt( defaultSimpleOpts, simpleOptExprWith )
import GHC.Core.Predicate
import GHC.Core.Coercion( Coercion )
import GHC.Core.Opt.Monad
@@ -594,9 +595,11 @@ Hence, the invariant is this:
-- | Specialise calls to type-class overloaded functions occurring in a program.
specProgram :: ModGuts -> CoreM ModGuts
specProgram guts@(ModGuts { mg_module = this_mod
- , mg_rules = local_rules
- , mg_binds = binds })
- = do { dflags <- getDynFlags
+ , mg_rules = local_rules
+ , mg_binds = binds })
+ = do { dflags <- getDynFlags
+ ; rule_env <- initRuleEnv guts
+ -- See Note [Fire rules in the specialiser]
-- We need to start with a Subst that knows all the things
-- that are in scope, so that the substitution engine doesn't
@@ -606,6 +609,7 @@ specProgram guts@(ModGuts { mg_module = this_mod
; let top_env = SE { se_subst = Core.mkEmptySubst $ mkInScopeSetList $
bindersOfBinds binds
, se_module = this_mod
+ , se_rules = rule_env
, se_dflags = dflags }
go [] = return ([], emptyUDs)
@@ -616,7 +620,7 @@ specProgram guts@(ModGuts { mg_module = this_mod
-- Specialise the bindings of this module
; (binds', uds) <- runSpecM (go binds)
- ; (spec_rules, spec_binds) <- specImports top_env local_rules uds
+ ; (spec_rules, spec_binds) <- specImports top_env uds
; return (guts { mg_binds = spec_binds ++ binds'
, mg_rules = spec_rules ++ local_rules }) }
@@ -681,21 +685,15 @@ specialisation (see canSpecImport):
-}
specImports :: SpecEnv
- -> [CoreRule]
-> UsageDetails
-> CoreM ([CoreRule], [CoreBind])
-specImports top_env local_rules
- (MkUD { ud_binds = dict_binds, ud_calls = calls })
+specImports top_env (MkUD { ud_binds = dict_binds, ud_calls = calls })
| not $ gopt Opt_CrossModuleSpecialise (se_dflags top_env)
-- See Note [Disabling cross-module specialisation]
= return ([], wrapDictBinds dict_binds [])
| otherwise
- = do { hpt_rules <- getRuleBase
- ; let rule_base = extendRuleBaseList hpt_rules local_rules
-
- ; (spec_rules, spec_binds) <- spec_imports top_env [] rule_base
- dict_binds calls
+ = do { (_env, spec_rules, spec_binds) <- spec_imports top_env [] dict_binds calls
-- Don't forget to wrap the specialized bindings with
-- bindings for the needed dictionaries.
@@ -713,89 +711,91 @@ specImports top_env local_rules
spec_imports :: SpecEnv -- Passed in so that all top-level Ids are in scope
-> [Id] -- Stack of imported functions being specialised
-- See Note [specImport call stack]
- -> RuleBase -- Rules from this module and the home package
- -- (but not external packages, which can change)
-> FloatedDictBinds -- Dict bindings, used /only/ for filterCalls
-- See Note [Avoiding loops in specImports]
-> CallDetails -- Calls for imported things
- -> CoreM ( [CoreRule] -- New rules
+ -> CoreM ( SpecEnv -- Env contains the new rules
+ , [CoreRule] -- New rules
, [CoreBind] ) -- Specialised bindings
-spec_imports top_env callers rule_base dict_binds calls
+spec_imports env callers dict_binds calls
= do { let import_calls = dVarEnvElts calls
-- ; debugTraceMsg (text "specImports {" <+>
-- vcat [ text "calls:" <+> ppr import_calls
-- , text "dict_binds:" <+> ppr dict_binds ])
- ; (rules, spec_binds) <- go rule_base import_calls
+ ; (env, rules, spec_binds) <- go env import_calls
-- ; debugTraceMsg (text "End specImports }" <+> ppr import_calls)
- ; return (rules, spec_binds) }
+ ; return (env, rules, spec_binds) }
where
- go :: RuleBase -> [CallInfoSet] -> CoreM ([CoreRule], [CoreBind])
- go _ [] = return ([], [])
- go rb (cis : other_calls)
+ go :: SpecEnv -> [CallInfoSet] -> CoreM (SpecEnv, [CoreRule], [CoreBind])
+ go env [] = return (env, [], [])
+ go env (cis : other_calls)
= do { -- debugTraceMsg (text "specImport {" <+> ppr cis)
- ; (rules1, spec_binds1) <- spec_import top_env callers rb dict_binds cis
+ ; (env, rules1, spec_binds1) <- spec_import env callers dict_binds cis
; -- debugTraceMsg (text "specImport }" <+> ppr cis)
- ; (rules2, spec_binds2) <- go (extendRuleBaseList rb rules1) other_calls
- ; return (rules1 ++ rules2, spec_binds1 ++ spec_binds2) }
+ ; (env, rules2, spec_binds2) <- go env other_calls
+ ; return (env, rules1 ++ rules2, spec_binds1 ++ spec_binds2) }
spec_import :: SpecEnv -- Passed in so that all top-level Ids are in scope
-> [Id] -- Stack of imported functions being specialised
-- See Note [specImport call stack]
- -> RuleBase -- Rules from this module
-> FloatedDictBinds -- Dict bindings, used /only/ for filterCalls
-- See Note [Avoiding loops in specImports]
-> CallInfoSet -- Imported function and calls for it
- -> CoreM ( [CoreRule] -- New rules
+ -> CoreM ( SpecEnv
+ , [CoreRule] -- New rules
, [CoreBind] ) -- Specialised bindings
-spec_import top_env callers rb dict_binds cis@(CIS fn _)
+spec_import env callers dict_binds cis@(CIS fn _)
| isIn "specImport" fn callers
- = return ([], []) -- No warning. This actually happens all the time
- -- when specialising a recursive function, because
- -- the RHS of the specialised function contains a recursive
- -- call to the original function
+ = return (env, [], []) -- No warning. This actually happens all the time
+ -- when specialising a recursive function, because
+ -- the RHS of the specialised function contains a recursive
+ -- call to the original function
| null good_calls
- = return ([], [])
+ = return (env, [], [])
| Just rhs <- canSpecImport dflags fn
= do { -- Get rules from the external package state
-- We keep doing this in case we "page-fault in"
-- more rules as we go along
- ; external_rule_base <- getExternalRuleBase
- ; vis_orphs <- getVisibleOrphanMods
- ; let rules_for_fn = getRules (RuleEnv [rb, external_rule_base] vis_orphs) fn
+ ; eps_rules <- getExternalRuleBase
+ ; let rule_env = se_rules env `updExternalPackageRules` eps_rules
- ; -- debugTraceMsg (text "specImport1" <+> vcat [ppr fn, ppr good_calls, ppr rhs])
+-- ; debugTraceMsg (text "specImport1" <+> vcat [ppr fn, ppr good_calls
+-- , ppr (getRules rule_env fn), ppr rhs])
; (rules1, spec_pairs, MkUD { ud_binds = dict_binds1, ud_calls = new_calls })
- <- runSpecM $ specCalls True top_env dict_binds
- rules_for_fn good_calls fn rhs
+ <- runSpecM $ specCalls True env dict_binds
+ (getRules rule_env fn) good_calls fn rhs
; let spec_binds1 = [NonRec b r | (b,r) <- spec_pairs]
-- After the rules kick in we may get recursion, but
-- we rely on a global GlomBinds to sort that out later
-- See Note [Glom the bindings if imported functions are specialised]
+ new_subst = se_subst env `Core.extendSubstInScopeList` map fst spec_pairs
+ new_env = env { se_rules = rule_env `addLocalRules` rules1
+ , se_subst = new_subst }
+
-- Now specialise any cascaded calls
- ; -- debugTraceMsg (text "specImport 2" <+> (ppr fn $$ ppr rules1 $$ ppr spec_binds1))
- ; (rules2, spec_binds2) <- spec_imports top_env
- (fn:callers)
- (extendRuleBaseList rb rules1)
- (dict_binds `thenFDBs` dict_binds1)
- new_calls
+-- ; debugTraceMsg (text "specImport 2" <+> (ppr fn $$ ppr rules1 $$ ppr spec_binds1))
+ ; (env, rules2, spec_binds2)
+ <- spec_imports new_env (fn:callers)
+ (dict_binds `thenFDBs` dict_binds1)
+ new_calls
; let final_binds = wrapDictBinds dict_binds1 $
spec_binds2 ++ spec_binds1
- ; return (rules2 ++ rules1, final_binds) }
+ ; return (env, rules2 ++ rules1, final_binds) }
| otherwise
= do { tryWarnMissingSpecs dflags callers fn good_calls
- ; return ([], [])}
+ ; return (env, [], [])}
where
- dflags = se_dflags top_env
+ dflags = se_dflags env
good_calls = filterCalls cis dict_binds
-- SUPER IMPORTANT! Drop calls that (directly or indirectly) refer to fn
-- See Note [Avoiding loops in specImports]
@@ -1086,6 +1086,7 @@ data SpecEnv
-- the RHS of specialised bindings (no type-let!)
, se_module :: Module
+ , se_rules :: RuleEnv -- From the home package and this module
, se_dflags :: DynFlags
}
@@ -1124,8 +1125,8 @@ specExpr env expr@(App {})
; (args_out, uds_args) <- mapAndCombineSM (specExpr env) args_in
; let env_args = env `bringFloatedDictsIntoScope` ud_binds uds_args
-- Some dicts may have floated out of args_in;
- -- they should be in scope for rewriteClassOps (#21689)
- (fun_in', args_out') = rewriteClassOps env_args fun_in args_out
+ -- they should be in scope for fireRewriteRules (#21689)
+ (fun_in', args_out') = fireRewriteRules env_args fun_in args_out
; (fun_out', uds_fun) <- specExpr env fun_in'
; let uds_call = mkCallUDs env fun_out' args_out'
; return (fun_out' `mkApps` args_out', uds_fun `thenUDs` uds_call `thenUDs` uds_args) }
@@ -1160,17 +1161,19 @@ specExpr env (Let bind body)
; return (foldr Let body' binds', uds) }
-- See Note [Specialisation modulo dictionary selectors]
--- and Note [ClassOp/DFun selection]
-rewriteClassOps :: SpecEnv -> InExpr -> [OutExpr] -> (InExpr, [OutExpr])
-rewriteClassOps env (Var f) args
- | isClassOpId f -- If we see `op_sel $fCInt`, we rewrite to `$copInt`
- , Just (rule, expr) <- -- pprTrace "rewriteClassOps" (ppr f $$ ppr args $$ ppr (se_subst env)) $
- specLookupRule env f args (idCoreRules f)
- , let rest_args = drop (ruleArity rule) args -- See Note [Extra args in the target]
--- , pprTrace "class op rewritten" (ppr f <+> ppr args $$ ppr expr <+> ppr rest_args) True
- , (fun, args) <- collectArgs expr
- = rewriteClassOps env fun (args++rest_args)
-rewriteClassOps _ fun args = (fun, args)
+-- Note [ClassOp/DFun selection]
+-- Note [Fire rules in the specialiser]
+fireRewriteRules :: SpecEnv -> InExpr -> [OutExpr] -> (InExpr, [OutExpr])
+fireRewriteRules env (Var f) args
+ | Just (rule, expr) <- specLookupRule env f args InitialPhase (getRules (se_rules env) f)
+ , let rest_args = drop (ruleArity rule) args -- See Note [Extra args in the target]
+ zapped_subst = Core.zapSubst (se_subst env)
+ expr' = simpleOptExprWith defaultSimpleOpts zapped_subst expr
+ -- simplOptExpr needed because lookupRule returns
+ -- (\x y. rhs) arg1 arg2
+ , (fun, args) <- collectArgs expr'
+ = fireRewriteRules env fun (args++rest_args)
+fireRewriteRules _ fun args = (fun, args)
--------------
specLam :: SpecEnv -> [OutBndr] -> InExpr -> SpecM (OutExpr, UsageDetails)
@@ -1276,7 +1279,61 @@ specCase env scrut case_bndr alts
where
(env_rhs, args') = substBndrs env_alt args
-{-
+{- Note [Fire rules in the specialiser]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Consider this (#21851)
+
+ module A where
+ f :: Num b => b -> (b, b)
+ f x = (x + 1, snd (f x))
+ {-# SPECIALIZE f :: Int -> (Int, Int) #-}
+
+ module B (g') where
+ import A
+
+ g :: Num a => a -> a
+ g x = fst (f x)
+ {-# NOINLINE[99] g #-}
+
+ h :: Int -> Int
+ h = g
+
+Note that `f` has the CPR property, and so will worker/wrapper.
+
+The call to `g` in `h` will make us specialise `g @Int`. And the specialised
+version of `g` will contain the call `f @Int`; but in the subsequent run of
+the Simplifier, there will be a competition between:
+* The user-supplied SPECIALISE rule for `f`
+* The inlining of the wrapper for `f`
+In fact, the latter wins -- see Note [Rewrite rules and inlining] in
+GHC.Core.Opt.Simplify.Iteration. However, it a bit fragile.
+
+Moreover consider (test T21851_2):
+
+ module A
+ f :: (Ord a, Show b) => a -> b -> blah
+ {-# RULE forall b. f @Int @b = wombat #-}
+
+ wombat :: Show b => Int -> b -> blah
+ wombat = blah
+
+ module B
+ import A
+ g :: forall a. Ord a => blah
+ g @a = ...g...f @a @Char....
+
+ h = ....g @Int....
+
+Now, in module B, GHC will specialise `g @Int`, which will lead to a
+call `f @Int @Char`. If we immediately (in the specialiser) rewrite
+that to `womabat @Char`, we have a chance to specialise `wombat`.
+
+Conclusion: it's treat if the Specialiser fires RULEs itself.
+It's not hard to achieve: see `fireRewriteRules`. The only tricky bit is
+making sure that we have a reasonably up to date EPS rule base. Currently
+we load it up just once, in `initRuleEnv`, called at the beginning of
+`specProgram`.
+
Note [Floating dictionaries out of cases]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Consider
@@ -1367,13 +1424,12 @@ specBind top_lvl env (NonRec fn rhs) do_body
final_binds :: [DictBind]
-- See Note [From non-recursive to recursive]
- final_binds
- | not (isNilOL dump_dbs)
- , not (null spec_defns)
- = [recWithDumpedDicts pairs dump_dbs]
- | otherwise
- = [mkDB $ NonRec b r | (b,r) <- pairs]
- ++ fromOL dump_dbs
+ final_binds | not (isNilOL dump_dbs)
+ , not (null spec_defns)
+ = [recWithDumpedDicts pairs dump_dbs]
+ | otherwise
+ = [mkDB $ NonRec b r | (b,r) <- pairs]
+ ++ fromOL dump_dbs
; if float_all then
-- Rather than discard the calls mentioning the bound variables
@@ -1505,8 +1561,10 @@ specCalls spec_imp env dict_binds existing_rules calls_for_me fn rhs
foldlM spec_call ([], [], emptyUDs) calls_for_me
| otherwise -- No calls or RHS doesn't fit our preconceptions
- = warnPprTrace (not (exprIsTrivial rhs) && notNull calls_for_me)
+ = warnPprTrace (not (exprIsTrivial rhs) && notNull calls_for_me && not (isClassOpId fn))
"Missed specialisation opportunity" (ppr fn $$ _trace_doc) $
+ -- isClassOpId: class-op Ids never inline; we specialise them
+ -- through fireRewriteRules. So don't complain about missed opportunities
-- Note [Specialisation shape]
-- pprTrace "specCalls: none" (ppr fn <+> ppr calls_for_me) $
return ([], [], emptyUDs)
@@ -1533,9 +1591,13 @@ specCalls spec_imp env dict_binds existing_rules calls_for_me fn rhs
already_covered :: SpecEnv -> [CoreRule] -> [CoreExpr] -> Bool
already_covered env new_rules args -- Note [Specialisations already covered]
- = isJust (specLookupRule env fn args (new_rules ++ existing_rules))
- -- NB: we look both in the new_rules (generated by this invocation
- -- of specCalls), and in existing_rules (passed in to specCalls)
+ = isJust (specLookupRule env fn args (beginPhase inl_act)
+ (new_rules ++ existing_rules))
+ -- Rules: we look both in the new_rules (generated by this invocation
+ -- of specCalls), and in existing_rules (passed in to specCalls)
+ -- inl_act: is the activation we are going to put in the new SPEC
+ -- rule; so we want to see if it is covered by another rule with
+ -- that same activation.
----------------------------------------------------------
-- Specialise to one particular call pattern
@@ -1653,13 +1715,16 @@ specCalls spec_imp env dict_binds existing_rules calls_for_me fn rhs
-- Convenience function for invoking lookupRule from Specialise
-- The SpecEnv's InScopeSet should include all the Vars in the [CoreExpr]
-specLookupRule :: SpecEnv -> Id -> [CoreExpr] -> [CoreRule] -> Maybe (CoreRule, CoreExpr)
-specLookupRule env fn args rules
- = lookupRule ropts (in_scope, realIdUnfolding) (const True) fn args rules
+specLookupRule :: SpecEnv -> Id -> [CoreExpr]
+ -> CompilerPhase -- Look up rules as if we were in this phase
+ -> [CoreRule] -> Maybe (CoreRule, CoreExpr)
+specLookupRule env fn args phase rules
+ = lookupRule ropts (in_scope, realIdUnfolding) is_active fn args rules
where
- dflags = se_dflags env
- in_scope = getSubstInScope (se_subst env)
- ropts = initRuleOpts dflags
+ dflags = se_dflags env
+ in_scope = getSubstInScope (se_subst env)
+ ropts = initRuleOpts dflags
+ is_active = isActive phase
{- Note [Specialising DFuns]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -1846,10 +1911,10 @@ We want to specialise this! How? By doing the method-selection rewrite in
the Specialiser. Hence
1. In the App case of 'specExpr', try to apply the ClassOp/DFun rule on the
- head of the application, repeatedly, via 'rewriteClassOps'.
+ head of the application, repeatedly, via 'fireRewriteRules'.
2. Attach an unfolding to freshly-bound dictionary ids such as `$dC` and
`$dShow` in `bindAuxiliaryDict`, so that we can exploit the unfolding
- in 'rewriteClassOps' to do the ClassOp/DFun rewrite.
+ in 'fireRewriteRules' to do the ClassOp/DFun rewrite.
NB: Without (2), (1) would be pointless, because 'lookupRule' wouldn't be able
to look into the RHS of `$dC` to see the DFun.
=====================================
compiler/GHC/Core/Rules.hs
=====================================
@@ -12,8 +12,10 @@ module GHC.Core.Rules (
lookupRule,
-- ** RuleBase, RuleEnv
+ RuleBase, RuleEnv(..), mkRuleEnv, emptyRuleEnv,
+ updExternalPackageRules, addLocalRules, updLocalRules,
emptyRuleBase, mkRuleBase, extendRuleBaseList,
- pprRuleBase, extendRuleEnv,
+ pprRuleBase,
-- ** Checking rule applications
ruleCheckProgram,
@@ -22,6 +24,8 @@ module GHC.Core.Rules (
extendRuleInfo, addRuleInfo,
addIdSpecialisations,
+ -- ** RuleBase and RuleEnv
+
-- * Misc. CoreRule helpers
rulesOfBinds, getRules, pprRulesForUser,
@@ -34,6 +38,8 @@ import GHC.Prelude
import GHC.Unit.Module ( Module )
import GHC.Unit.Module.Env
+import GHC.Unit.Module.ModGuts( ModGuts(..) )
+import GHC.Unit.Module.Deps( Dependencies(..) )
import GHC.Driver.Session( DynFlags )
import GHC.Driver.Ppr( showSDoc )
@@ -136,7 +142,7 @@ Note [Overall plumbing for rules]
* At the moment (c) is carried in a reader-monad way by the GHC.Core.Opt.Monad.
The HomePackageTable doesn't have a single RuleBase because technically
we should only be able to "see" rules "below" this module; so we
- generate a RuleBase for (c) by combing rules from all the modules
+ generate a RuleBase for (c) by combining rules from all the modules
"below" us. That's why we can't just select the home-package RuleBase
from HscEnv.
@@ -340,12 +346,100 @@ addIdSpecialisations id rules
rulesOfBinds :: [CoreBind] -> [CoreRule]
rulesOfBinds binds = concatMap (concatMap idCoreRules . bindersOf) binds
+
+{-
+************************************************************************
+* *
+ RuleBase
+* *
+************************************************************************
+-}
+
+-- | Gathers a collection of 'CoreRule's. Maps (the name of) an 'Id' to its rules
+type RuleBase = NameEnv [CoreRule]
+ -- The rules are unordered;
+ -- we sort out any overlaps on lookup
+
+emptyRuleBase :: RuleBase
+emptyRuleBase = emptyNameEnv
+
+mkRuleBase :: [CoreRule] -> RuleBase
+mkRuleBase rules = extendRuleBaseList emptyRuleBase rules
+
+extendRuleBaseList :: RuleBase -> [CoreRule] -> RuleBase
+extendRuleBaseList rule_base new_guys
+ = foldl' extendRuleBase rule_base new_guys
+
+extendRuleBase :: RuleBase -> CoreRule -> RuleBase
+extendRuleBase rule_base rule
+ = extendNameEnv_Acc (:) Utils.singleton rule_base (ruleIdName rule) rule
+
+pprRuleBase :: RuleBase -> SDoc
+pprRuleBase rules = pprUFM rules $ \rss ->
+ vcat [ pprRules (tidyRules emptyTidyEnv rs)
+ | rs <- rss ]
+
+-- | A full rule environment which we can apply rules from. Like a 'RuleBase',
+-- but it also includes the set of visible orphans we use to filter out orphan
+-- rules which are not visible (even though we can see them...)
+-- See Note [Orphans] in GHC.Core
+data RuleEnv
+ = RuleEnv { re_local_rules :: !RuleBase -- Rules from this module
+ , re_home_rules :: !RuleBase -- Rule from the home package
+ -- (excl this module)
+ , re_eps_rules :: !RuleBase -- Rules from other packages
+ -- see Note [External package rules]
+ , re_visible_orphs :: !ModuleSet
+ }
+
+mkRuleEnv :: ModGuts -> RuleBase -> RuleBase -> RuleEnv
+mkRuleEnv (ModGuts { mg_module = this_mod
+ , mg_deps = deps
+ , mg_rules = local_rules })
+ eps_rules hpt_rules
+ = RuleEnv { re_local_rules = mkRuleBase local_rules
+ , re_home_rules = hpt_rules
+ , re_eps_rules = eps_rules
+ , re_visible_orphs = mkModuleSet vis_orphs }
+ where
+ vis_orphs = this_mod : dep_orphs deps
+
+updExternalPackageRules :: RuleEnv -> RuleBase -> RuleEnv
+-- Completely over-ride the external rules in RuleEnv
+updExternalPackageRules rule_env eps_rules
+ = rule_env { re_eps_rules = eps_rules }
+
+updLocalRules :: RuleEnv -> [CoreRule] -> RuleEnv
+-- Completely over-ride the local rules in RuleEnv
+updLocalRules rule_env local_rules
+ = rule_env { re_local_rules = mkRuleBase local_rules }
+
+addLocalRules :: RuleEnv -> [CoreRule] -> RuleEnv
+-- Add new local rules
+addLocalRules rule_env rules
+ = rule_env { re_local_rules = extendRuleBaseList (re_local_rules rule_env) rules }
+
+emptyRuleEnv :: RuleEnv
+emptyRuleEnv = RuleEnv { re_local_rules = emptyNameEnv
+ , re_home_rules = emptyNameEnv
+ , re_eps_rules = emptyNameEnv
+ , re_visible_orphs = emptyModuleSet }
+
getRules :: RuleEnv -> Id -> [CoreRule]
+-- Given a RuleEnv and an Id, find the visible rules for that Id
-- See Note [Where rules are found]
-getRules (RuleEnv { re_base = rule_base, re_visible_orphs = orphs }) fn
- = idCoreRules fn ++ concatMap imp_rules rule_base
+getRules (RuleEnv { re_local_rules = local_rules
+ , re_home_rules = home_rules
+ , re_eps_rules = eps_rules
+ , re_visible_orphs = orphs }) fn
+ = idCoreRules fn ++
+ get local_rules ++
+ find_visible home_rules ++
+ find_visible eps_rules
where
- imp_rules rb = filter (ruleIsVisible orphs) (lookupNameEnv rb (idName fn) `orElse` [])
+ fn_name = idName fn
+ find_visible rb = filter (ruleIsVisible orphs) (get rb)
+ get rb = lookupNameEnv rb fn_name `orElse` []
ruleIsVisible :: ModuleSet -> CoreRule -> Bool
ruleIsVisible _ BuiltinRule{} = True
@@ -371,37 +465,28 @@ but that isn't quite right:
in the module defining the Id (when it's a LocalId), but
the rules are kept in the global RuleBase
+ Note [External package rules]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In Note [Overall plumbing for rules], it is explained that the final
+RuleBase which we must consider is combined from 4 different sources.
-************************************************************************
-* *
- RuleBase
-* *
-************************************************************************
--}
-
--- RuleBase itself is defined in GHC.Core, along with CoreRule
-
-emptyRuleBase :: RuleBase
-emptyRuleBase = emptyNameEnv
-
-mkRuleBase :: [CoreRule] -> RuleBase
-mkRuleBase rules = extendRuleBaseList emptyRuleBase rules
+During simplifier runs, the fourth source of rules is constantly being updated
+as new interfaces are loaded into the EPS. Therefore just before we check to see
+if any rules match we get the EPS RuleBase and combine it with the existing RuleBase
+and then perform exactly 1 lookup into the new map.
-extendRuleBaseList :: RuleBase -> [CoreRule] -> RuleBase
-extendRuleBaseList rule_base new_guys
- = foldl' extendRuleBase rule_base new_guys
+It is more efficient to avoid combining the environments and store the uncombined
+environments as we can instead perform 1 lookup into each environment and then combine
+the results.
-extendRuleBase :: RuleBase -> CoreRule -> RuleBase
-extendRuleBase rule_base rule
- = extendNameEnv_Acc (:) Utils.singleton rule_base (ruleIdName rule) rule
+Essentially we use the identity:
-extendRuleEnv :: RuleEnv -> RuleBase -> RuleEnv
-extendRuleEnv (RuleEnv rules orphs) rb = (RuleEnv (rb:rules) orphs)
+> lookupNameEnv n (plusNameEnv_C (++) rb1 rb2)
+> = lookupNameEnv n rb1 ++ lookupNameEnv n rb2
-pprRuleBase :: RuleBase -> SDoc
-pprRuleBase rules = pprUFM rules $ \rss ->
- vcat [ pprRules (tidyRules emptyTidyEnv rs)
- | rs <- rss ]
+The latter being more efficient as we don't construct an intermediate
+map.
+-}
{-
************************************************************************
@@ -1576,7 +1661,7 @@ ruleCheckFun env fn args
| otherwise = unitBag (ruleAppCheck_help env fn args name_match_rules)
where
name_match_rules = filter match (rc_rules env fn)
- match rule = (rc_pattern env) `isPrefixOf` unpackFS (ruleName rule)
+ match rule = rc_pattern env `isPrefixOf` unpackFS (ruleName rule)
ruleAppCheck_help :: RuleCheckEnv -> Id -> [CoreExpr] -> [CoreRule] -> SDoc
ruleAppCheck_help env fn args rules
=====================================
compiler/GHC/Driver/Config/Core/Opt/Simplify.hs
=====================================
@@ -7,7 +7,7 @@ module GHC.Driver.Config.Core.Opt.Simplify
import GHC.Prelude
-import GHC.Core ( RuleBase )
+import GHC.Core.Rules ( RuleBase )
import GHC.Core.Opt.Pipeline.Types ( CoreToDo(..) )
import GHC.Core.Opt.Simplify ( SimplifyExprOpts(..), SimplifyOpts(..) )
import GHC.Core.Opt.Simplify.Env ( FloatEnable(..), SimplMode(..) )
@@ -40,20 +40,19 @@ initSimplifyExprOpts dflags ic = SimplifyExprOpts
}
initSimplifyOpts :: DynFlags -> [Var] -> Int -> SimplMode -> RuleBase -> SimplifyOpts
-initSimplifyOpts dflags extra_vars iterations mode rule_base = let
+initSimplifyOpts dflags extra_vars iterations mode hpt_rule_base = let
-- This is a particularly ugly construction, but we will get rid of it in !8341.
opts = SimplifyOpts
{ so_dump_core_sizes = not $ gopt Opt_SuppressCoreSizes dflags
- , so_iterations = iterations
- , so_mode = mode
+ , so_iterations = iterations
+ , so_mode = mode
, so_pass_result_cfg = if gopt Opt_DoCoreLinting dflags
- then Just $ initLintPassResultConfig dflags extra_vars (CoreDoSimplify opts)
- else Nothing
- , so_rule_base = rule_base
- , so_top_env_cfg = TopEnvConfig
- { te_history_size = historySize dflags
- , te_tick_factor = simplTickFactor dflags
- }
+ then Just $ initLintPassResultConfig dflags extra_vars
+ (CoreDoSimplify opts)
+ else Nothing
+ , so_hpt_rules = hpt_rule_base
+ , so_top_env_cfg = TopEnvConfig { te_history_size = historySize dflags
+ , te_tick_factor = simplTickFactor dflags }
}
in opts
=====================================
compiler/GHC/Unit/External.hs
=====================================
@@ -21,11 +21,10 @@ import GHC.Prelude
import GHC.Unit
import GHC.Unit.Module.ModIface
-import GHC.Core ( RuleBase )
import GHC.Core.FamInstEnv
import GHC.Core.InstEnv ( InstEnv, emptyInstEnv )
import GHC.Core.Opt.ConstantFold
-import GHC.Core.Rules (mkRuleBase)
+import GHC.Core.Rules ( RuleBase, mkRuleBase)
import GHC.Types.Annotations ( AnnEnv, emptyAnnEnv )
import GHC.Types.CompleteMatch
=====================================
libraries/base/GHC/Real.hs
=====================================
@@ -701,11 +701,14 @@ half of y - 1 can be computed as y `quot` 2, optimising subtraction away.
Note [Inlining (^)
~~~~~~~~~~~~~~~~~~
-The INLINABLE pragma allows (^) to be specialised at its call sites.
+The INLINABLE [1] pragma allows (^) to be specialised at its call sites.
If it is called repeatedly at the same type, that can make a huge
difference, because of those constants which can be repeatedly
calculated.
+We don't inline until phase 1, to give a chance for the RULES
+"^2/Int" etc to fire first.
+
Currently the fromInteger calls are not floated because we get
\d1 d2 x y -> blah
after the gentle round of simplification.
=====================================
testsuite/tests/simplCore/should_compile/T21851.stderr
=====================================
@@ -15,5 +15,3 @@ g' :: Int -> Int
g'
= \ (x :: Int) -> case T21851a.$w$sf x of { (# ww, ww1 #) -> ww }
-
-
=====================================
testsuite/tests/simplCore/should_compile/T21851_2.hs
=====================================
@@ -0,0 +1,15 @@
+{-# OPTIONS_GHC -ddump-simpl -dsuppress-uniques -dno-typeable-binds #-}
+
+module T21851_2 where
+
+import T21851_2a
+
+g :: forall a. (Ord a, Num a) => a -> (a,String)
+g n | n < 10 = (0, f n True)
+ | otherwise = g (n-2)
+-- The specialised version of g leads to a specialised
+-- call to (f @Int @Bool). Then we want to fire f's RULE
+-- and specialise 'wombat'
+
+h = g (3::Int)
+
=====================================
testsuite/tests/simplCore/should_compile/T21851_2.stderr
=====================================
@@ -0,0 +1,120 @@
+[1 of 2] Compiling T21851_2a ( T21851_2a.hs, T21851_2a.o )
+[2 of 2] Compiling T21851_2 ( T21851_2.hs, T21851_2.o )
+
+==================== Tidy Core ====================
+Result size of Tidy Core
+ = {terms: 107, types: 96, coercions: 0, joins: 0/0}
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl :: Integer
+[GblId, Unf=OtherCon []]
+lvl = GHC.Num.Integer.IS 2#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl1 :: Integer
+[GblId, Unf=OtherCon []]
+lvl1 = GHC.Num.Integer.IS 0#
+
+-- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
+lvl2 :: Integer
+[GblId, Unf=OtherCon []]
+lvl2 = GHC.Num.Integer.IS 10#
+
+Rec {
+-- RHS size: {terms: 25, types: 5, coercions: 0, joins: 0/0}
+T21851_2.$s$wwombat [InlPrag=[~], Occ=LoopBreaker]
+ :: GHC.Prim.Int# -> Bool -> [Char]
+[GblId, Arity=2, Str=<1L><ML>, Unf=OtherCon []]
+T21851_2.$s$wwombat
+ = \ (ww :: GHC.Prim.Int#) (y :: Bool) ->
+ case ww of ds {
+ __DEFAULT ->
+ case y of {
+ False ->
+ GHC.CString.unpackAppendCString#
+ GHC.Show.$fShowBool3
+ (T21851_2.$s$wwombat (GHC.Prim.-# ds 1#) GHC.Types.False);
+ True ->
+ GHC.CString.unpackAppendCString#
+ GHC.Show.$fShowBool2
+ (T21851_2.$s$wwombat (GHC.Prim.-# ds 1#) GHC.Types.True)
+ };
+ 0# -> GHC.Types.[] @Char
+ }
+end Rec }
+
+Rec {
+-- RHS size: {terms: 16, types: 6, coercions: 0, joins: 0/0}
+T21851_2.$w$sg [InlPrag=[2], Occ=LoopBreaker]
+ :: GHC.Prim.Int# -> (# GHC.Prim.Int#, String #)
+[GblId, Arity=1, Str=<L>, Unf=OtherCon []]
+T21851_2.$w$sg
+ = \ (ww :: GHC.Prim.Int#) ->
+ case GHC.Prim.<# ww 10# of {
+ __DEFAULT -> T21851_2.$w$sg (GHC.Prim.-# ww 2#);
+ 1# -> (# 0#, T21851_2.$s$wwombat ww GHC.Types.True #)
+ }
+end Rec }
+
+-- RHS size: {terms: 3, types: 3, coercions: 0, joins: 0/0}
+lvl3 :: forall {a}. [Char]
+[GblId]
+lvl3 = \ (@a) -> T21851_2a.$wf GHC.Prim.(##) @a @Bool
+
+Rec {
+-- RHS size: {terms: 27, types: 18, coercions: 0, joins: 0/0}
+T21851_2.$wg [InlPrag=[2], Occ=LoopBreaker]
+ :: forall {a}. (Ord a, Num a) => a -> (# a, String #)
+[GblId[StrictWorker([!])],
+ Arity=3,
+ Str=<SP(A,A,SC(S,C(1,L)),A,A,A,A,A)><LP(A,LC(L,C(1,L)),A,A,A,A,L)><L>,
+ Unf=OtherCon []]
+T21851_2.$wg
+ = \ (@a) ($dOrd :: Ord a) ($dNum :: Num a) (n :: a) ->
+ case < @a $dOrd n (fromInteger @a $dNum lvl2) of {
+ False ->
+ T21851_2.$wg
+ @a $dOrd $dNum (- @a $dNum n (fromInteger @a $dNum lvl));
+ True -> (# fromInteger @a $dNum lvl1, lvl3 @a #)
+ }
+end Rec }
+
+-- RHS size: {terms: 13, types: 16, coercions: 0, joins: 0/0}
+g [InlPrag=[2]] :: forall a. (Ord a, Num a) => a -> (a, String)
+[GblId,
+ Arity=3,
+ Str=<SP(A,A,SC(S,C(1,L)),A,A,A,A,A)><LP(A,LC(L,C(1,L)),A,A,A,A,L)><L>,
+ Cpr=1,
+ Unf=Unf{Src=StableSystem, TopLvl=True, Value=True, ConLike=True,
+ WorkFree=True, Expandable=True,
+ Guidance=ALWAYS_IF(arity=3,unsat_ok=True,boring_ok=False)
+ Tmpl= \ (@a)
+ ($dOrd [Occ=Once1] :: Ord a)
+ ($dNum [Occ=Once1] :: Num a)
+ (n [Occ=Once1] :: a) ->
+ case T21851_2.$wg @a $dOrd $dNum n of
+ { (# ww [Occ=Once1], ww1 [Occ=Once1] #) ->
+ (ww, ww1)
+ }}]
+g = \ (@a) ($dOrd :: Ord a) ($dNum :: Num a) (n :: a) ->
+ case T21851_2.$wg @a $dOrd $dNum n of { (# ww, ww1 #) ->
+ (ww, ww1)
+ }
+
+-- RHS size: {terms: 8, types: 9, coercions: 0, joins: 0/0}
+h :: (Int, String)
+[GblId,
+ Unf=Unf{Src=<vanilla>, TopLvl=True, Value=False, ConLike=False,
+ WorkFree=False, Expandable=False, Guidance=IF_ARGS [] 50 10}]
+h = case T21851_2.$w$sg 3# of { (# ww, ww1 #) ->
+ (GHC.Types.I# ww, ww1)
+ }
+
+
+------ Local rules for imported ids --------
+"SPEC/T21851_2 $wwombat @Bool" [2]
+ forall ($dShow :: Show Bool).
+ T21851_2a.$wwombat @Bool $dShow
+ = T21851_2.$s$wwombat
+
+
=====================================
testsuite/tests/simplCore/should_compile/T21851_2a.hs
=====================================
@@ -0,0 +1,11 @@
+module T21851_2a where
+
+f :: (Num a, Show b) => a -> b -> String
+{-# NOINLINE f #-}
+f x y = "no"
+{-# RULES "wombat" f = wombat #-}
+
+wombat :: Show b => Int -> b -> String
+{-# INLINEABLE wombat #-}
+wombat 0 y = ""
+wombat n y = show y ++ wombat (n-1) y
=====================================
testsuite/tests/simplCore/should_compile/all.T
=====================================
@@ -434,3 +434,7 @@ test('T21286', normal, multimod_compile, ['T21286', '-O -ddump-rule-firings'])
test('T21851', [grep_errmsg(r'case.*w\$sf') ], multimod_compile, ['T21851', '-O -dno-typeable-binds -dsuppress-uniques'])
# One module, T22097.hs, has OPTIONS_GHC -ddump-simpl
test('T22097', [grep_errmsg(r'case.*wgoEven') ], multimod_compile, ['T22097', '-O -dno-typeable-binds -dsuppress-uniques'])
+
+# One module, T21851_2.hs, has OPTIONS_GHC -ddump-simpl
+# Expecting to see $s$wwombat
+test('T21851_2', [grep_errmsg(r'wwombat') ], multimod_compile, ['T21851_2', '-O -dno-typeable-binds -dsuppress-uniques'])
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b3b1ddd8784556ba6c9a69cca1c80d665b5e991b
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b3b1ddd8784556ba6c9a69cca1c80d665b5e991b
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