Cheng Shao pushed to branch wip/ghci-no-simpl at Glasgow Haskell Compiler / GHC Commits: 5d35dc97 by Cheng Shao at 2025-09-14T12:35:55+02:00 compiler: use modified dflags/session with -O0 in hscCompileCoreExpr This commit makes the compiler use modified dflags/session with -O0 in hscCompileCoreExpr to do less work in not just the Core simplification step, but also later steps, especially the STG -> STG pipeline. - - - - - c307ec77 by Cheng Shao at 2025-09-14T12:35:55+02:00 compiler: remove unused simplifyExpr logic This commit removes the now unused simplifyExpr logic in the tree. - - - - - 4 changed files: - compiler/GHC/Core/Opt/Pipeline.hs - compiler/GHC/Core/Opt/Simplify.hs - compiler/GHC/Driver/Config/Core/Opt/Simplify.hs - compiler/GHC/Driver/Main.hs Changes: ===================================== compiler/GHC/Core/Opt/Pipeline.hs ===================================== @@ -6,7 +6,7 @@ {-# LANGUAGE CPP #-} -module GHC.Core.Opt.Pipeline ( core2core, simplifyExpr ) where +module GHC.Core.Opt.Pipeline ( core2core ) where import GHC.Prelude @@ -27,7 +27,7 @@ import GHC.Core.Ppr ( pprCoreBindings ) import GHC.Core.Utils ( dumpIdInfoOfProgram ) import GHC.Core.Lint ( lintAnnots ) import GHC.Core.Lint.Interactive ( interactiveInScope ) -import GHC.Core.Opt.Simplify ( simplifyExpr, simplifyPgm ) +import GHC.Core.Opt.Simplify ( simplifyPgm ) import GHC.Core.Opt.Simplify.Monad import GHC.Core.Opt.Monad import GHC.Core.Opt.Pipeline.Types ===================================== compiler/GHC/Core/Opt/Simplify.hs ===================================== @@ -1,8 +1,8 @@ {-# LANGUAGE CPP #-} module GHC.Core.Opt.Simplify - ( SimplifyExprOpts(..), SimplifyOpts(..) - , simplifyExpr, simplifyPgm + ( SimplifyOpts(..) + , simplifyPgm ) where import GHC.Prelude @@ -11,20 +11,18 @@ import GHC.Driver.Flags import GHC.Core import GHC.Core.Rules -import GHC.Core.Ppr ( pprCoreBindings, pprCoreExpr ) -import GHC.Core.Opt.OccurAnal ( occurAnalysePgm, occurAnalyseExpr ) -import GHC.Core.Stats ( coreBindsSize, coreBindsStats, exprSize ) +import GHC.Core.Ppr ( pprCoreBindings ) +import GHC.Core.Opt.OccurAnal ( occurAnalysePgm ) +import GHC.Core.Stats ( coreBindsSize, coreBindsStats ) import GHC.Core.Utils ( mkTicks, stripTicksTop ) import GHC.Core.Lint ( LintPassResultConfig, dumpPassResult, lintPassResult ) -import GHC.Core.Opt.Simplify.Iteration ( simplTopBinds, simplExpr, simplImpRules ) +import GHC.Core.Opt.Simplify.Iteration ( simplTopBinds, simplImpRules ) import GHC.Core.Opt.Simplify.Utils ( activeRule ) import GHC.Core.Opt.Simplify.Inline ( activeUnfolding ) import GHC.Core.Opt.Simplify.Env import GHC.Core.Opt.Simplify.Monad import GHC.Core.Opt.Stats ( simplCountN ) -import GHC.Core.FamInstEnv -import GHC.Utils.Error ( withTiming ) import GHC.Utils.Logger as Logger import GHC.Utils.Outputable import GHC.Utils.Constants (debugIsOn) @@ -44,72 +42,6 @@ import GHC.Types.Unique.FM import Control.Monad import Data.Foldable ( for_ ) -{- -************************************************************************ -* * - Gentle simplification -* * -************************************************************************ --} - --- | Configuration record for `simplifyExpr`. --- The values of this datatype are /only/ driven by the demands of that function. -data SimplifyExprOpts = SimplifyExprOpts - { se_fam_inst :: ![FamInst] - , se_mode :: !SimplMode - , se_top_env_cfg :: !TopEnvConfig - } - -simplifyExpr :: Logger - -> ExternalUnitCache - -> SimplifyExprOpts - -> CoreExpr - -> IO CoreExpr --- ^ Simplify an expression using 'simplExprGently'. --- --- See 'simplExprGently' for details. -simplifyExpr logger euc opts expr - = withTiming logger (text "Simplify [expr]") (const ()) $ - do { eps <- eucEPS euc ; - ; let fam_envs = ( eps_fam_inst_env eps - , extendFamInstEnvList emptyFamInstEnv $ se_fam_inst opts - ) - simpl_env = mkSimplEnv (se_mode opts) fam_envs - top_env_cfg = se_top_env_cfg opts - read_eps_rules = eps_rule_base <$> eucEPS euc - read_ruleenv = updExternalPackageRules emptyRuleEnv <$> read_eps_rules - - ; let sz = exprSize expr - - ; (expr', counts) <- initSmpl logger read_ruleenv top_env_cfg sz $ - simplExprGently simpl_env expr - - ; Logger.putDumpFileMaybe logger Opt_D_dump_simpl_stats - "Simplifier statistics" FormatText (pprSimplCount counts) - - ; Logger.putDumpFileMaybe logger Opt_D_dump_simpl "Simplified expression" - FormatCore - (pprCoreExpr expr') - - ; return expr' - } - -simplExprGently :: SimplEnv -> CoreExpr -> SimplM CoreExpr --- ^ Simplifies an expression by doing occurrence analysis, then simplification, --- and repeating (twice currently), because one pass alone leaves tons of crud. --- --- Used only: --- --- 1. for user expressions typed in at the interactive prompt (see 'GHC.Driver.Main.hscStmt'), --- 2. for Template Haskell splices (see 'GHC.Tc.Gen.Splice.runMeta'). --- --- The name 'Gently' suggests that the SimplMode is InitialPhase, --- and in fact that is so.... but the 'Gently' in 'simplExprGently' doesn't --- enforce that; it just simplifies the expression twice. -simplExprGently env expr = do - expr1 <- simplExpr env (occurAnalyseExpr expr) - simplExpr env (occurAnalyseExpr expr1) - {- ************************************************************************ * * ===================================== compiler/GHC/Driver/Config/Core/Opt/Simplify.hs ===================================== @@ -1,6 +1,5 @@ module GHC.Driver.Config.Core.Opt.Simplify - ( initSimplifyExprOpts - , initSimplifyOpts + ( initSimplifyOpts , initSimplMode , initGentleSimplMode ) where @@ -9,7 +8,7 @@ import GHC.Prelude import GHC.Core.Rules ( RuleBase ) import GHC.Core.Opt.Pipeline.Types ( CoreToDo(..) ) -import GHC.Core.Opt.Simplify ( SimplifyExprOpts(..), SimplifyOpts(..) ) +import GHC.Core.Opt.Simplify ( SimplifyOpts(..) ) import GHC.Core.Opt.Simplify.Env ( FloatEnable(..), SimplMode(..), SimplPhase(..) ) import GHC.Core.Opt.Simplify.Monad ( TopEnvConfig(..) ) @@ -19,26 +18,9 @@ import GHC.Driver.Config.Core.Rules ( initRuleOpts ) import GHC.Driver.Config.Core.Opt.Arity ( initArityOpts ) import GHC.Driver.DynFlags ( DynFlags(..), GeneralFlag(..), gopt ) -import GHC.Runtime.Context ( InteractiveContext(..) ) - import GHC.Types.Basic ( CompilerPhase(..) ) import GHC.Types.Var ( Var ) -initSimplifyExprOpts :: DynFlags -> InteractiveContext -> SimplifyExprOpts -initSimplifyExprOpts dflags ic = SimplifyExprOpts - { se_fam_inst = snd $ ic_instances ic - , se_mode = (initSimplMode dflags InitialPhase "GHCi") - { sm_inline = False - -- Do not do any inlining, in case we expose some - -- unboxed tuple stuff that confuses the bytecode - -- interpreter - } - , se_top_env_cfg = TopEnvConfig - { te_history_size = historySize dflags - , te_tick_factor = simplTickFactor dflags - } - } - initSimplifyOpts :: DynFlags -> [Var] -> Int -> SimplMode -> RuleBase -> SimplifyOpts 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. ===================================== compiler/GHC/Driver/Main.hs ===================================== @@ -2709,28 +2709,35 @@ hscCompileCoreExpr hsc_env loc expr = Just h -> h hsc_env loc expr hscCompileCoreExpr' :: HscEnv -> SrcSpan -> CoreExpr -> IO (ForeignHValue, [Linkable], PkgsLoaded) -hscCompileCoreExpr' hsc_env srcspan ds_expr = do - {- Simplify it -} - let dflags = hsc_dflags hsc_env +hscCompileCoreExpr' hsc_env' srcspan ds_expr = do + -- Use modified `dflags` and session that sets -O0 and do less work + -- throughout the Core -> ByteCode pipeline under + -- `-funoptimized-core-for-interpreter`, even if current session + -- enables `-O1` or above. + let dflags' = hsc_dflags hsc_env' + unopt = gopt Opt_UnoptimizedCoreForInterpreter dflags' + dflags + | unopt = updOptLevel 0 dflags' + | otherwise = dflags' + hsc_env + | unopt = hsc_env' {hsc_dflags = dflags} + | otherwise = hsc_env' let logger = hsc_logger hsc_env + {- Simplify it -} let simpl_expr - -- Do less work under `-funoptimized-core-for-interpreter`, - -- use modified `dflags` that sets `-O0` here even if current - -- session enables `-O1` or above. - -- -- When generating bytecode for ghci via `hscParsedStmt`, we -- still need to enable inlining! For `let foo = Foo ...`, the -- ghci debugger expects `:print foo` to show `foo = <Foo> ...` -- without forcing `foo` first, without inlining `foo` -- would remain a top-level thunk instead of a datacon -- closure. We can skip inlining for TH splices though. - | gopt Opt_UnoptimizedCoreForInterpreter dflags = + | unopt = ( if srcspan == interactiveSrcSpan then simpleOptExpr else simpleOptExprNoInline ) - (initSimpleOpts $ updOptLevel 0 dflags) + (initSimpleOpts dflags) ds_expr | otherwise = simpleOptExpr (initSimpleOpts dflags) ds_expr View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fbc6f309570160457258b7de3a286a5... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fbc6f309570160457258b7de3a286a5... You're receiving this email because of your account on gitlab.haskell.org.