November 2025 - ghc-commits

[Git][ghc/ghc][wip/T23559] 2 commits: Switch off specialisation in ExactPrint
by Simon Peyton Jones (＠simonpj) 26 Nov '25

26 Nov '25

Simon Peyton Jones pushed to branch wip/T23559 at Glasgow Haskell Compiler / GHC Commits: 89a3718e by Simon Peyton Jones at 2025-11-26T14:59:23+00:00 Switch off specialisation in ExactPrint In !15057 (where we re-introduced -fpolymoprhic-specialisation) we found that ExactPrint's compile time blew up by a factor of 5. It turned out to be caused by bazillions of specialisations of `markAnnotated`. Since ExactPrint isn't perf-critical, it does not seem worth taking the performance hit, so this patch switches off specialisation in this one module. - - - - - 85b1977f by Simon Peyton Jones at 2025-11-26T14:59:32+00:00 Switch -fpolymorphic-specialisation on by default This patch addresses #23559. Now that !10479 has landed and #26329 is fixed, we can switch on polymorphic specialisation by default, addressing a bunch of other tickets listed in #23559. Metric changes: * CoOpt_Singleton: +4% compiler allocations: we just get more specialisations * info_table_map_perf: -20% decrease in compiler allocations. This is caused by using -fno-specialise in ExactPrint.hs Without that change we get a 4x blow-up in compile time; see !15058 for details Metric Decrease: info_table_map_perf Metric Increase: CoOpt_Singletons - - - - - 4 changed files: - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/Flags.hs - docs/users_guide/using-optimisation.rst - utils/check-exact/ExactPrint.hs Changes: ===================================== compiler/GHC/Driver/DynFlags.hs ===================================== @@ -1268,6 +1268,7 @@ optLevelFlags -- see Note [Documenting optimisation flags] , ([1,2], Opt_CfgBlocklayout) -- Experimental , ([1,2], Opt_Specialise) + , ([1,2], Opt_PolymorphicSpecialisation) -- Now on by default (#23559) , ([1,2], Opt_CrossModuleSpecialise) , ([1,2], Opt_InlineGenerics) , ([1,2], Opt_Strictness) ===================================== compiler/GHC/Driver/Flags.hs ===================================== @@ -909,6 +909,7 @@ optimisationFlags = EnumSet.fromList , Opt_SpecialiseAggressively , Opt_CrossModuleSpecialise , Opt_StaticArgumentTransformation + , Opt_PolymorphicSpecialisation , Opt_CSE , Opt_StgCSE , Opt_StgLiftLams ===================================== docs/users_guide/using-optimisation.rst ===================================== @@ -1325,10 +1325,7 @@ as such you shouldn't need to set any of them explicitly. A flag :reverse: -fno-polymorphic-specialisation :category: - :default: off - - Warning, this feature is highly experimental and may lead to incorrect runtime - results. Use at your own risk (:ghc-ticket:`23469`, :ghc-ticket:`23109`, :ghc-ticket:`21229`, :ghc-ticket:`23445`). + :default: on Enable specialisation of function calls to known dictionaries with free type variables. The created specialisation will abstract over the type variables free in the dictionary. ===================================== utils/check-exact/ExactPrint.hs ===================================== @@ -19,6 +19,13 @@ {-# LANGUAGE UndecidableInstances #-} -- For the (StmtLR GhcPs GhcPs (LocatedA (body GhcPs))) ExactPrint instance {-# OPTIONS_GHC -Wno-incomplete-uni-patterns -Wno-incomplete-record-updates #-} +-- We switch off specialisation in this module. Otherwise we get lots of functions +-- specialised on lots of (GHC syntax tree) data types. Compilation time allocation +-- (at least with -fpolymorphic-specialisation; see !15058) blows up from 17G to 108G. +-- Bad! ExactPrint is not a performance-critical module so it's not worth taking the +-- largely-fruitless hit in compile time. +{-# OPTIONS_GHC -fno-specialise #-} + module ExactPrint ( ExactPrint(..) View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ecf0dbebf541e533a1beff1aec767a… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ecf0dbebf541e533a1beff1aec767a… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/int-index/imp-exp-whole-namespace] 6 commits: Build external interpreter program on demand (#24731)
by Vladislav Zavialov (＠int-index) 26 Nov '25

26 Nov '25

Vladislav Zavialov pushed to branch wip/int-index/imp-exp-whole-namespace at Glasgow Haskell Compiler / GHC Commits: 55eab80d by Sylvain Henry at 2025-11-20T17:33:13-05:00 Build external interpreter program on demand (#24731) This patch teaches GHC how to build the external interpreter program when it is missing. As long as we have the `ghci` library, doing this is trivial so most of this patch is refactoring for doing it sanely. - - - - - 08bbc028 by Rodrigo Mesquita at 2025-11-20T17:33:54-05:00 Add tests for #23973 and #26565 These were fixed by 4af4f0f070f83f948e49ad5d7835fd91b8d3f0e6 in !10417 - - - - - 6b42232c by sheaf at 2025-11-20T17:34:35-05:00 Mark T26410_ffi as fragile on Windows As seen in #26595, this test intermittently fails on Windows. This commit marks it as fragile, until we get around to fixing it. - - - - - b7b7c049 by Andrew Lelechenko at 2025-11-21T21:04:01+00:00 Add nubOrd / nubOrdBy to Data.List and Data.List.NonEmpty As per https://github.com/haskell/core-libraries-committee/issues/336 - - - - - 352d5462 by Marc Scholten at 2025-11-22T10:33:03-05:00 Fix haddock test runner to handle UTF-8 output xhtml 3000.4.0.0 now produces UTF-8 output instead of escaping non-ASCII characters. When using --test-accept it previously wrote files in the wrong encoding because they have not been decoded properly when reading the files. - - - - - 3e714d6e by Vladislav Zavialov at 2025-11-26T14:29:40+03:00 Namespace-specified wildcards in import/export lists (#25901) This change adds support for top-level namespace-specified wildcards `type ..` and `data ..` to import and export lists. Examples: import M (type ..) -- imports all type and class constructors from M import M (data ..) -- imports all data constructors and terms from M module M (type .., f) where -- exports all type and class constructors defined in M, -- plus the function 'f' The primary intended usage of this feature is in combination with module aliases, allowing namespace disambiguation: import Data.Proxy as T (type ..) -- T.Proxy is unambiguously the type constructor import Data.Proxy as D (data ..) -- D.Proxy is unambiguously the data constructor The patch accounts for the interactions of wildcards with: * Imports with `hiding` clauses * Import warnings -Wunused-imports, -Wdodgy-imports * Export warnings -Wduplicate-exports, -Wdodgy-exports Summary of the changes: 1. Move the NamespaceSpecifier type from GHC.Hs.Binds to GHC.Hs.Basic, making it possible to use it in more places in the AST. 2. Extend the AST (type: IE) with a representation of `..`, `type ..`, and `data ..` (constructor: IEWholeNamespace). Per the proposal, the plain `..` is always rejected with a dedicated error message. 3. Extend the grammar in Parser.y with productions for `..`, `type ..`, and `data ..` in both import and export lists. 4. Implement wildcard imports by updating the `filterImports` function in GHC.Rename.Names; the logic for IEWholeNamespace is roughly modeled after the Nothing (no explicit import list) case. 5. Implement wildcard exports by updating the `exports_from_avail` function in GHC.Tc.Gen.Export; the logic for IEWholeNamespace is closely modeled after the IEModuleContents case. 6. Refactor and extend diagnostics to report the new warnings and errors. See PsErrPlainWildcardImport, DodgyImportsWildcard, PsErrPlainWildcardExport, DodgyExportsWildcard, TcRnDupeWildcardExport. Note that this patch is specifically about top-level import/export items. Subordinate import/export items are left unchanged. - - - - - 119 changed files: - compiler/GHC.hs - + compiler/GHC/Driver/Config/Interpreter.hs - compiler/GHC/Driver/Config/Linker.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/Pipeline.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Hs/Basic.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Linker/Config.hs - compiler/GHC/Linker/Dynamic.hs - + compiler/GHC/Linker/Executable.hs - − compiler/GHC/Linker/ExtraObj.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Linker/MacOS.hs - compiler/GHC/Linker/Static.hs - compiler/GHC/Linker/Windows.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/Errors/Types.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Names.hs - + compiler/GHC/Runtime/Interpreter/C.hs - + compiler/GHC/Runtime/Interpreter/Init.hs - compiler/GHC/SysTools/Tasks.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Hint.hs - compiler/GHC/Types/Hint/Ppr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/ImpExp.hs - compiler/ghc.cabal.in - docs/users_guide/9.16.1-notes.rst - docs/users_guide/exts/explicit_namespaces.rst - libraries/base/base.cabal.in - libraries/base/changelog.md - libraries/base/src/Data/List.hs - libraries/base/src/Data/List/NonEmpty.hs - + libraries/base/src/Data/List/NubOrdSet.hs - libraries/ghc-internal/src/GHC/Internal/Data/OldList.hs - + testsuite/tests/bytecode/T23973.hs - + testsuite/tests/bytecode/T23973.script - + testsuite/tests/bytecode/T23973.stdout - + testsuite/tests/bytecode/T26565.hs - + testsuite/tests/bytecode/T26565.script - + testsuite/tests/bytecode/T26565.stdout - testsuite/tests/bytecode/all.T - + testsuite/tests/driver/T24731.hs - testsuite/tests/driver/all.T - testsuite/tests/interface-stability/base-exports.stdout - testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs - testsuite/tests/interface-stability/base-exports.stdout-mingw32 - testsuite/tests/interface-stability/base-exports.stdout-ws-32 - + testsuite/tests/module/T25901_exp_plain_wc.hs - + testsuite/tests/module/T25901_exp_plain_wc.stderr - + testsuite/tests/module/T25901_imp_plain_wc.hs - + testsuite/tests/module/T25901_imp_plain_wc.stderr - testsuite/tests/module/all.T - + testsuite/tests/rename/should_compile/T25901_exp_1.hs - + testsuite/tests/rename/should_compile/T25901_exp_1_helper.hs - + testsuite/tests/rename/should_compile/T25901_exp_2.hs - + testsuite/tests/rename/should_compile/T25901_exp_2_helper.hs - + testsuite/tests/rename/should_compile/T25901_imp_hq.hs - + testsuite/tests/rename/should_compile/T25901_imp_hu.hs - + testsuite/tests/rename/should_compile/T25901_imp_sq.hs - + testsuite/tests/rename/should_compile/T25901_imp_su.hs - testsuite/tests/rename/should_compile/all.T - + testsuite/tests/rename/should_fail/T25901_exp_fail_1.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_1.stderr - + testsuite/tests/rename/should_fail/T25901_exp_fail_1_helper.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_2.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_2.stderr - + testsuite/tests/rename/should_fail/T25901_exp_fail_2_helper.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_5.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_5.stderr - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_6.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_6.stderr - + testsuite/tests/rename/should_fail/T25901_imp_hu_fail_4.hs - + testsuite/tests/rename/should_fail/T25901_imp_hu_fail_4.stderr - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_2.hs - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_2.stderr - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_3.hs - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_3.stderr - + testsuite/tests/rename/should_fail/T25901_imp_su_fail_1.hs - + testsuite/tests/rename/should_fail/T25901_imp_su_fail_1.stderr - testsuite/tests/rename/should_fail/all.T - testsuite/tests/simd/should_run/all.T - + testsuite/tests/warnings/should_compile/T25901_exp_dodgy.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dodgy.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_1.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_1.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_2.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_2.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_3.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_3.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_4.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_4.stderr - + testsuite/tests/warnings/should_compile/T25901_helper_1.hs - + testsuite/tests/warnings/should_compile/T25901_helper_2.hs - + testsuite/tests/warnings/should_compile/T25901_helper_3.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_1.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_1.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_2.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_2.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_1.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_1.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_2.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_2.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_3.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_3.stderr - testsuite/tests/warnings/should_compile/all.T - utils/check-exact/ExactPrint.hs - utils/haddock/haddock-test/src/Test/Haddock.hs - utils/iserv/iserv.cabal.in The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/58f7734f571fe7a09689c43ce6c646… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/58f7734f571fe7a09689c43ce6c646… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26425] Remove a quadratic-cost assertion check in mkCoreApp
by Simon Peyton Jones (＠simonpj) 26 Nov '25

26 Nov '25

Simon Peyton Jones pushed to branch wip/T26425 at Glasgow Haskell Compiler / GHC Commits: f1959dfc by Simon Peyton Jones at 2025-11-26T11:58:07+00:00 Remove a quadratic-cost assertion check in mkCoreApp See the new Note [Assertion checking in mkCoreApp] - - - - - 5 changed files: - compiler/GHC/Core/Make.hs - compiler/GHC/HsToCore/Binds.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/Match.hs - testsuite/tests/unboxedsums/UbxSumUnpackedSize.hs Changes: ===================================== compiler/GHC/Core/Make.hs ===================================== @@ -151,37 +151,28 @@ mkCoreConWrapApps con args = mkCoreApps (Var (dataConWrapId con)) args -- | Construct an expression which represents the application of a number of -- expressions to another. The leftmost expression in the list is applied first -mkCoreApps :: CoreExpr -- ^ function +-- See Note [Assertion checking in mkCoreApp] +mkCoreApps :: CoreExpr -- ^ function -> [CoreExpr] -- ^ arguments -> CoreExpr -mkCoreApps fun args - = fst $ - foldl' (mkCoreAppTyped doc_string) (fun, fun_ty) args - where - doc_string = ppr fun_ty $$ ppr fun $$ ppr args - fun_ty = exprType fun +mkCoreApps fun args = foldl' mkCoreApp fun args -- | Construct an expression which represents the application of one expression -- to the other -mkCoreApp :: SDoc - -> CoreExpr -- ^ function +-- See Note [Assertion checking in mkCoreApp] +mkCoreApp :: CoreExpr -- ^ function -> CoreExpr -- ^ argument -> CoreExpr -mkCoreApp s fun arg - = fst $ mkCoreAppTyped s (fun, exprType fun) arg - --- | Construct an expression which represents the application of one expression --- paired with its type to an argument. The result is paired with its type. This --- function is not exported and used in the definition of 'mkCoreApp' and --- 'mkCoreApps'. -mkCoreAppTyped :: SDoc -> (CoreExpr, Type) -> CoreExpr -> (CoreExpr, Type) -mkCoreAppTyped _ (fun, fun_ty) (Type ty) - = (App fun (Type ty), piResultTy fun_ty ty) -mkCoreAppTyped _ (fun, fun_ty) (Coercion co) - = (App fun (Coercion co), funResultTy fun_ty) -mkCoreAppTyped d (fun, fun_ty) arg - = assertPpr (isFunTy fun_ty) (ppr fun $$ ppr arg $$ d) - (App fun arg, funResultTy fun_ty) +mkCoreApp fun arg = App fun arg + +{- Note [Assertion checking in mkCoreApp] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +At one time we had an assertion to check that the function and argument type match up, +but that turned out to take 90% of all compile time (!) when compiling test +`unboxedsums/UbxSumUnpackedSize.hs`. The reason was an unboxed sum constructor with +hundreds of foralls. It's most straightforward just to remove the assert, and +rely on Lint to discover any mis-constructed terms. +-} {- ********************************************************************* * * ===================================== compiler/GHC/HsToCore/Binds.hs ===================================== @@ -1620,7 +1620,7 @@ ds_hs_wrapper hs_wrap do { x <- newSysLocalDs (mkScaled (subMultCoRKind w_co) t) ; go c1 $ \w1 -> go c2 $ \w2 -> - let app f a = mkCoreApp (text "dsHsWrapper") f a + let app f a = mkCoreApp f a arg = w1 (Var x) in k (\e -> (Lam x (w2 (app e arg)))) } ===================================== compiler/GHC/HsToCore/Expr.hs ===================================== @@ -877,8 +877,7 @@ dsHsConLike (PatSynCon ps) | Just (builder_name, _, add_void) <- patSynBuilder ps = do { builder_id <- dsLookupGlobalId builder_name ; return (if add_void - then mkCoreApp (text "dsConLike" <+> ppr ps) - (Var builder_id) unboxedUnitExpr + then mkCoreApp (Var builder_id) unboxedUnitExpr else Var builder_id) } | otherwise = pprPanic "dsConLike" (ppr ps) ===================================== compiler/GHC/HsToCore/Match.hs ===================================== @@ -301,7 +301,7 @@ matchView (var :| vars) ty eqns@(eqn1 :| _) -- compile the view expressions ; viewExpr' <- dsExpr viewExpr ; return (mkViewMatchResult var' - (mkCoreApp (text "matchView") viewExpr' (Var var)) + (mkCoreApp viewExpr' (Var var)) match_result) } -- decompose the first pattern and leave the rest alone ===================================== testsuite/tests/unboxedsums/UbxSumUnpackedSize.hs ===================================== @@ -133,6 +133,124 @@ data U_E1 = U_E1 {-# UNPACK #-} !E1 {-# UNPACK #-} !Int8 deriving (Show) +{- In `data U_E`, the {-# UNPACK #-} !E1 gives rise to a pretty clumsy expression + for the wrapper for U_E1. Here is what it looks like when ther are only 16 + data constructors in E1, and we have just + data U_E1 = U_E1 {-# UNPACK #-} !E1 + Blimey! + +Main.$WU_E1 + = \ (conrep_t1N4 [Occ=Once1!] :: Main.E1) -> + case case conrep_t1N4 of { + Main.E1_1 -> + GHC.Internal.Types.(# _| | | | | | | | | | | | | | | #) + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + GHC.Internal.Types.(##); + Main.E1_2 -> + GHC.Internal.Types.(# |_| | | | | | | | | | | | | | #) + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + GHC.Internal.Types.(##); + Main.E1_3 -> + GHC.Internal.Types.(# | |_| | | | | | | | | | | | | #) + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @GHC.Internal.Types.ZeroBitRep + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + @(# #) + GHC.Internal.Types.(##); + + ... etc .... +-} + data U_E2 = U_E2 {-# UNPACK #-} !E2 {-# UNPACK #-} !Int8 {-# UNPACK #-} !Int8 View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f1959dfcfc2ecac6e8c91ecba950397… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f1959dfcfc2ecac6e8c91ecba950397… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T23559] 35 commits: Preserve user-written kinds in data declarations
by Simon Peyton Jones (＠simonpj) 26 Nov '25

26 Nov '25

Simon Peyton Jones pushed to branch wip/T23559 at Glasgow Haskell Compiler / GHC Commits: 3c2f4bb4 by sheaf at 2025-11-11T11:47:28-05:00 Preserve user-written kinds in data declarations This commit ensures that we preserve the user-written kind for data declarations, e.g. in type T2T = Type -> Type type D :: T2T data D a where { .. } that we preserve the user-written kind of D as 'T2T', instead of expanding the type synonym 'T2T' during kind checking. We do this by storing 'tyConKind' separately from 'tyConResKind'. This means that 'tyConKind' is not necessarily equal to 'mkTyConKind binders res_kind', as e.g. in the above example the former is 'T2T' while the latter is 'Type -> Type'. This is explained in Note [Preserve user-written TyCon kind] in GHC.Core.TyCon. This is particularly important for Haddock, as the kinds stored in interface files affect the generated documentation, and we want to preserve the user-written types as much as possible. - - - - - 19859584 by sheaf at 2025-11-11T11:47:28-05:00 Store user-written datacon tvs in interface files This commit ensures we store the user-written quantified type variables of data constructors in interface files, e.g. in data D a where MkD1 :: forall x. x -> D x MkD2 :: forall u v. u -> v -> D v The previous behaviour was to rename the universal variables to match the universal variables of the data constructor. This was undesirable because the names that end up in interface files end up mattering for generated Haddock documentation; it's better to preserve the user-written type variables. Moreover, the universal variables may not have been user-written at all, e.g. in an example such as: type T2T = Type -> Type data G :: T2T where MkG :: forall x. D x Here GHC will invent the type variable name 'a' for the first binder of the TyCon G. We really don't want to then rename the user-written 'x' into the generated 'a'. - - - - - 034b2056 by sheaf at 2025-11-11T11:47:28-05:00 DataCon univ_tvs names: pick TyCon over inferred This commit changes how we compute the names of universal type variables in GADT data constructors. This augments the existing logic that chose which type variable name to use, in GHC.Tc.TyCl.mkGADTVars. We continue to prefer DataCon tv names for user-written binders, but we now prefer TyCon tv names for inferred (non-user-written) DataCon binders. This makes a difference in examples such as: type (:~~:) :: k1 -> k2 -> Type data a :~~: b where HRefl :: a :~~: a Before this patch, we ended up giving HRefl the type: forall {k2}. forall (a :: k2). a :~~: a whereas we now give it the type: forall {k1}. forall (a :: k1). a :~~: a The important part isn't really 'k1' or 'k2', but more that the inferred type variable names of the DataCon can be arbitrary/unpredictable (as they are chosen by GHC and depend on how unification proceeds), so it's much better to use the more predictable TyCon type variable names. - - - - - 95078d00 by sheaf at 2025-11-11T11:47:28-05:00 Backpack Rename: use explicit record construction This commit updates the Backpack boilerplate in GHC.Iface.Rename to use explicit record construction rather than record update. This makes sure that the code stays up to date when the underlying constructors change (e.g. new fields are added). The rationale is further explained in Note [Prefer explicit record construction]. - - - - - 2bf36263 by sheaf at 2025-11-11T11:47:28-05:00 Store # eta binders in TyCon and use for Haddock This commit stores the number of TyCon binders that were introduced by eta-expansion (by the function GHC.Tc.Gen.HsType.splitTyConKind). This is then used to pretty-print the TyCon as the user wrote it, e.g. for type Effect :: (Type -> Type) -> Type -> Type data State s :: Effect where {..} -- arity 3 GHC will eta-expand the data declaration to data State s a b where {..} but also store in the 'TyCon' that the number of binders introduced by this eta expansion is 2. This allows us, in 'Haddock.Convert.synifyTyConKindSig', to recover the original user-written syntax, preserving the user's intent in Haddock documentation. See Note [Inline kind signatures with GADTSyntax] in Haddock.Convert. - - - - - 6c91582f by Matthew Pickering at 2025-11-11T11:48:12-05:00 driver: Properly handle errors during LinkNode steps Previously we were not properly catching errors during the LinkNode step (see T9930fail test). This is fixed by wrapping the `LinkNode` action in `wrapAction`, the same handler which is used for module compilation. Fixes #26496 - - - - - e1e1eb32 by Matthew Pickering at 2025-11-11T11:48:54-05:00 driver: Remove unecessary call to hscInsertHPT This call was left-over from e9445c013fbccf9318739ca3d095a3e0a2e1be8a If you follow the functions which call `upsweep_mod`, they immediately add the interface to the HomePackageTable when `upsweep_mod` returns. - - - - - b22777d4 by ARATA Mizuki at 2025-11-11T11:49:44-05:00 LLVM backend: Pass the +evex512 attribute to LLVM 18+ if -mavx512f is set The newer LLVM requires the +evex512 attribute to enable use of ZMM registers. LLVM exhibits a backward-compatible behavior if the cpu is `x86-64`, but not if `penryn`. Therefore, on macOS, where the cpu is set to `penryn`, we need to explicitly pass +evex512. Fixes #26410 - - - - - 6ead7d06 by Vladislav Zavialov at 2025-11-11T11:50:26-05:00 Comments only in GHC.Parser.PostProcess.Haddock Remove outdated Note [Register keyword location], as the issue it describes was addressed by commit 05eb50dff2fcc78d025e77b9418ddb369db49b9f. - - - - - 43fa8be8 by sheaf at 2025-11-11T11:51:18-05:00 localRegistersConflict: account for assignment LHS This commit fixes a serious oversight in GHC.Cmm.Sink.conflicts, specifically the code that computes which local registers conflict between an assignment and a Cmm statement. If we have: assignment: <local_reg> = <expr> node: <local_reg> = <other_expr> then clearly the two conflict, because we cannot move one statement past the other, as they assign two different values to the same local register. (Recall that 'conflicts (local_reg,expr) node' is False if and only if the assignment 'local_reg = expr' can be safely commuted past the statement 'node'.) The fix is to update 'GHC.Cmm.Sink.localRegistersConflict' to take into account the following two situations: (1) 'node' defines the LHS local register of the assignment, (2) 'node' defines a local register used in the RHS of the assignment. The bug is precisely that we were previously missing condition (1). Fixes #26550 - - - - - 79dfcfe0 by sheaf at 2025-11-11T11:51:18-05:00 Update assigned register format when spilling When we come to spilling a register to put new data into it, in GHC.CmmToAsm.Reg.Linear.allocRegsAndSpill_spill, we need to: 1. Spill the data currently in the register. That is, do a spill with a format that matches what's currently in the register. 2. Update the register assignment, allocating a virtual register to this real register, but crucially **updating the format** of this assignment. Due to shadowing in the Haskell code for allocRegsAndSpill_spill, we were mistakenly re-using the old format. This could lead to a situation where: a. We were using xmm6 to store a Double#. b. We want to store a DoubleX2# into xmm6, so we spill the current content of xmm6 to the stack using a scalar move (correct). c. We update the register assignment, but we fail to update the format of the assignment, so we continue to think that xmm6 stores a Double# and not a DoubleX2#. d. Later on, we need to spill xmm6 because it is getting clobbered by another instruction. We then decide to only spill the lower 64 bits of the register, because we still think that xmm6 only stores a Double# and not a DoubleX2#. Fixes #26542 - - - - - aada5db9 by ARATA Mizuki at 2025-11-11T11:52:07-05:00 Fix the order of spill/reload instructions The AArch64 NCG could emit multiple instructions for a single spill/reload, but their order was not consistent between the definition and a use. Fixes #26537 Co-authored-by: sheaf <sam.derbyshire(a)gmail.com> - - - - - 64ec82ff by Andreas Klebinger at 2025-11-11T11:52:48-05:00 Add hpc to release script - - - - - 741da00c by Ben Gamari at 2025-11-12T03:38:20-05:00 template-haskell: Better describe getQ semantics Clarify that the state is a type-indexed map, as suggested by #26484. - - - - - 8b080e04 by ARATA Mizuki at 2025-11-12T03:39:11-05:00 Fix incorrect markups in the User's Guide * Correct markup for C--: "C-\-" in reST * Fix internal links * Fix code highlighting * Fix inline code: Use ``code`` rather than `code` * Remove extra backslashes Fixes #16812 Co-authored-by: sheaf <sam.derbyshire(a)gmail.com> - - - - - a00840ea by Simon Peyton Jones at 2025-11-14T15:23:56+00:00 Make TYPE and CONSTRAINT apart again This patch finally fixes #24279. * The story started with #11715 * Then #21623 articulated a plan, which made Type and Constraint not-apart; a horrible hack but it worked. The main patch was commit 778c6adca2c995cd8a1b84394d4d5ca26b915dac Author: Simon Peyton Jones <simonpj(a)microsoft.com> Date: Wed Nov 9 10:33:22 2022 +0000 Type vs Constraint: finally nailed * #24279 reported a bug in the above big commit; this small patch fixes it commit af6932d6c068361c6ae300d52e72fbe13f8e1f18 Author: Simon Peyton Jones <simon.peytonjones(a)gmail.com> Date: Mon Jan 8 10:49:49 2024 +0000 Make TYPE and CONSTRAINT not-apart Issue #24279 showed up a bug in the logic in GHC.Core.Unify.unify_ty which is supposed to make TYPE and CONSTRAINT be not-apart. * Then !10479 implemented "unary classes". * That change in turn allows us to make Type and Constraint apart again, cleaning up the compiler and allowing a little bit more expressiveness. It fixes the original hope in #24279, namely that `Type` and `Constraint` should be distinct throughout. - - - - - c0a1e574 by Georgios Karachalias at 2025-11-15T05:14:31-05:00 Report all missing modules with -M We now report all missing modules at once in GHC.Driver.Makefile.processDeps, as opposed to only reporting a single missing module. Fixes #26551. - - - - - c9fa3449 by Sylvain Henry at 2025-11-15T05:15:26-05:00 JS: fix array index for registers We used to store R32 in h$regs[-1]. While it's correct in JavaScript, fix this to store R32 in h$regs[0] instead. - - - - - 9e469909 by Sylvain Henry at 2025-11-15T05:15:26-05:00 JS: support more than 128 registers (#26558) The JS backend only supported 128 registers (JS variables/array slots used to pass function arguments). It failed in T26537 when 129 registers were required. This commit adds support for more than 128 registers: it is now limited to maxBound :: Int (compiler's Int). If we ever go above this threshold the compiler now panics with a more descriptive message. A few built-in JS functions were assuming 128 registers and have been rewritten to use loops. Note that loops are only used for "high" registers that are stored in an array: the 31 "low" registers are still handled with JS global variables and with explicit switch-cases to maintain good performance in the most common cases (i.e. few registers used). Adjusting the number of low registers is now easy: just one constant to adjust (GHC.StgToJS.Regs.lowRegsCount). No new test added: T26537 is used as a regression test instead. - - - - - 0a64a78b by Sven Tennie at 2025-11-15T20:31:10-05:00 AArch64: Simplify CmmAssign and CmmStore The special handling for floats was fake: The general case is always used. So, the additional code path isn't needed (and only adds complexity for the reader.) - - - - - 15b311be by sheaf at 2025-11-15T20:32:02-05:00 SimpleOpt: refactor & push coercions into lambdas This commit improves the simple optimiser (in GHC.Core.SimpleOpt) in a couple of ways: - The logic to push coercion lambdas is shored up. The function 'pushCoercionIntoLambda' used to be called in 'finish_app', but this meant we could not continue to optimise the program after performing this transformation. Now, we call 'pushCoercionIntoLambda' as part of 'simple_app'. Doing so can be important when dealing with unlifted newtypes, as explained in Note [Desugaring unlifted newtypes]. - The code is re-structured to avoid duplication and out-of-sync code paths. Now, 'simple_opt_expr' defers to 'simple_app' for the 'App', 'Var', 'Cast' and 'Lam' cases. This means all the logic for those is centralised in a single place (e.g. the 'go_lam' helper function). To do this, the general structure is brought a bit closer to the full-blown simplifier, with a notion of 'continuation' (see 'SimpleContItem'). This commit also modifies GHC.Core.Opt.Arity.pushCoercionIntoLambda to apply a substitution (a slight generalisation of its existing implementation). - - - - - b33284c7 by sheaf at 2025-11-15T20:32:02-05:00 Improve typechecking of data constructors This commit changes the way in which we perform typecheck data constructors, in particular how we make multiplicities line up. Now, impedance matching occurs as part of the existing subsumption machinery. See the revamped Note [Typechecking data constructors] in GHC.Tc.Gen.App, as well as Note [Polymorphisation of linear fields] in GHC.Core.Multiplicity. This allows us to get rid of a fair amount of hacky code that was added with the introduction of LinearTypes; in particular the logic of GHC.Tc.Gen.Head.tcInferDataCon. ------------------------- Metric Decrease: T10421 T14766 T15164 T15703 T19695 T5642 T9630 WWRec ------------------------- - - - - - b6faf5d0 by sheaf at 2025-11-15T20:32:02-05:00 Handle unsaturated rep-poly newtypes This commit allows GHC to handle unsaturated occurrences of unlifted newtype constructors. The plan is detailed in Note [Eta-expanding rep-poly unlifted newtypes] in GHC.Tc.Utils.Concrete: for unsaturated unlifted newtypes, we perform the appropriate representation-polymorphism check in tcInstFun. - - - - - 682bf979 by Mike Pilgrem at 2025-11-16T16:44:14+00:00 Fix #26293 Valid stack.yaml for hadrian - - - - - acc70c3a by Simon Peyton Jones at 2025-11-18T16:21:20-05:00 Fix a bug in defaulting Addresses #26582 Defaulting was doing some unification but then failing to iterate. Silly. I discovered that the main solver was unnecessarily iterating even if there was a unification for an /outer/ unification variable, so I fixed that too. - - - - - c12fa73e by Simon Peyton Jones at 2025-11-19T02:55:01-05:00 Make PmLit be in Ord, and use it in Map This MR addresses #26514, by changing from data PmAltConSet = PACS !(UniqDSet ConLike) ![PmLit] to data PmAltConSet = PACS !(UniqDSet ConLike) !(Map PmLit PmLit) This matters when doing pattern-match overlap checking, when there is a very large set of patterns. For most programs it makes no difference at all. For the N=5000 case of the repro case in #26514, compiler mutator time (with `-fno-code`) goes from 1.9s to 0.43s. All for the price for an Ord instance for PmLit - - - - - 41b84f40 by sheaf at 2025-11-19T02:55:52-05:00 Add passing tests for #26311 and #26072 This commit adds two tests cases that now pass since landing the changes to typechecking of data constructors in b33284c7. Fixes #26072 #26311 - - - - - 1faa758a by sheaf at 2025-11-19T02:55:52-05:00 mkCast: weaken bad cast warning for multiplicity This commit weakens the warning message emitted when constructing a bad cast in mkCast to ignore multiplicity. Justification: since b33284c7, GHC uses sub-multiplicity coercions to typecheck data constructors. The coercion optimiser is free to discard these coercions, both for performance reasons, and because GHC's Core simplifier does not (yet) preserve linearity. We thus weaken 'mkCast' to use 'eqTypeIgnoringMultiplicity' instead of 'eqType', to avoid getting many spurious warnings about mismatched multiplicities. - - - - - 55eab80d by Sylvain Henry at 2025-11-20T17:33:13-05:00 Build external interpreter program on demand (#24731) This patch teaches GHC how to build the external interpreter program when it is missing. As long as we have the `ghci` library, doing this is trivial so most of this patch is refactoring for doing it sanely. - - - - - 08bbc028 by Rodrigo Mesquita at 2025-11-20T17:33:54-05:00 Add tests for #23973 and #26565 These were fixed by 4af4f0f070f83f948e49ad5d7835fd91b8d3f0e6 in !10417 - - - - - 6b42232c by sheaf at 2025-11-20T17:34:35-05:00 Mark T26410_ffi as fragile on Windows As seen in #26595, this test intermittently fails on Windows. This commit marks it as fragile, until we get around to fixing it. - - - - - b7b7c049 by Andrew Lelechenko at 2025-11-21T21:04:01+00:00 Add nubOrd / nubOrdBy to Data.List and Data.List.NonEmpty As per https://github.com/haskell/core-libraries-committee/issues/336 - - - - - 352d5462 by Marc Scholten at 2025-11-22T10:33:03-05:00 Fix haddock test runner to handle UTF-8 output xhtml 3000.4.0.0 now produces UTF-8 output instead of escaping non-ASCII characters. When using --test-accept it previously wrote files in the wrong encoding because they have not been decoded properly when reading the files. - - - - - 938ce308 by Simon Peyton Jones at 2025-11-26T09:58:44+00:00 Switch -fpolymorphic-specialisation on by default This patch addresses #23559. Now that !10479 has landed and #26329 is fixed, we can switch on polymorphic specialisation by default, addressing a bunch of other tickets listed in #23559. - - - - - ecf0dbeb by Simon Peyton Jones at 2025-11-26T09:58:44+00:00 Switch off specialisation in ExactPrint In !15057 (where we re-introduced -fpolymoprhic-specialisation) we found that ExactPrint's compile time blew up by a factor of 5. It turned out to be caused by bazillions of specialisations of `markAnnotated`. Since ExactPrint isn't perf-critical, it does not seem worth taking the performance hit, so this patch switches off specialisation in this one module. - - - - - 245 changed files: - .gitlab/rel_eng/upload_ghc_libs.py - compiler/GHC.hs - compiler/GHC/Builtin/Types.hs - compiler/GHC/Builtin/Types/Literals.hs - compiler/GHC/Builtin/Types/Prim.hs - compiler/GHC/Cmm/Sink.hs - compiler/GHC/CmmToAsm/AArch64/CodeGen.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Liveness.hs - compiler/GHC/Core.hs - compiler/GHC/Core/Coercion.hs - compiler/GHC/Core/Coercion/Opt.hs - compiler/GHC/Core/DataCon.hs - compiler/GHC/Core/Lint.hs - compiler/GHC/Core/Multiplicity.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/RoughMap.hs - compiler/GHC/Core/SimpleOpt.hs - compiler/GHC/Core/TyCo/FVs.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/TyCon.hs - compiler/GHC/Core/Type.hs - compiler/GHC/Core/Unify.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/Driver/Config/Core/Lint.hs - + compiler/GHC/Driver/Config/Interpreter.hs - compiler/GHC/Driver/Config/Linker.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/Flags.hs - compiler/GHC/Driver/Make.hs - compiler/GHC/Driver/MakeFile.hs - compiler/GHC/Driver/Pipeline.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/Hs/Syn/Type.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/HsToCore/Binds.hs - compiler/GHC/HsToCore/Expr.hs - compiler/GHC/HsToCore/Match.hs - compiler/GHC/HsToCore/Pmc/Solver/Types.hs - compiler/GHC/HsToCore/Utils.hs - compiler/GHC/Iface/Decl.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Rename.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Type.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Linker/Config.hs - compiler/GHC/Linker/Dynamic.hs - + compiler/GHC/Linker/Executable.hs - − compiler/GHC/Linker/ExtraObj.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Linker/MacOS.hs - compiler/GHC/Linker/Static.hs - compiler/GHC/Linker/Windows.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - + compiler/GHC/Runtime/Interpreter/C.hs - + compiler/GHC/Runtime/Interpreter/Init.hs - compiler/GHC/StgToJS/Apply.hs - compiler/GHC/StgToJS/Expr.hs - compiler/GHC/StgToJS/Regs.hs - compiler/GHC/StgToJS/Rts/Rts.hs - compiler/GHC/StgToJS/Rts/Types.hs - compiler/GHC/SysTools/Tasks.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Expr.hs-boot - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Match.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Instance/Class.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Solver/Solve.hs - compiler/GHC/Tc/TyCl.hs - compiler/GHC/Tc/TyCl/Build.hs - compiler/GHC/Tc/TyCl/Instance.hs - compiler/GHC/Tc/Types/Evidence.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Concrete.hs - compiler/GHC/Tc/Utils/TcType.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Tc/Zonk/Type.hs - 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testsuite/tests/saks/should_compile/saks035.stdout - testsuite/tests/showIface/Makefile - + testsuite/tests/showIface/T26246a.hs - + testsuite/tests/showIface/T26246a.stdout - testsuite/tests/showIface/all.T - + testsuite/tests/simd/should_run/T26410_ffi.hs - + testsuite/tests/simd/should_run/T26410_ffi.stdout - + testsuite/tests/simd/should_run/T26410_ffi_c.c - + testsuite/tests/simd/should_run/T26410_prim.hs - + testsuite/tests/simd/should_run/T26410_prim.stdout - + testsuite/tests/simd/should_run/T26542.hs - + testsuite/tests/simd/should_run/T26542.stdout - + testsuite/tests/simd/should_run/T26550.hs - + testsuite/tests/simd/should_run/T26550.stdout - testsuite/tests/simd/should_run/all.T - testsuite/tests/typecheck/T16127/T16127.stderr - testsuite/tests/typecheck/should_compile/T22560d.stdout - + testsuite/tests/typecheck/should_compile/T26582.hs - testsuite/tests/typecheck/should_compile/all.T - testsuite/tests/typecheck/should_fail/T15629.stderr - testsuite/tests/typecheck/should_fail/T15883e.stderr - testsuite/tests/typecheck/should_fail/T2414.stderr - testsuite/tests/typecheck/should_fail/T24279.hs - − testsuite/tests/typecheck/should_fail/T24279.stderr - testsuite/tests/typecheck/should_fail/T2534.stderr - testsuite/tests/typecheck/should_fail/T7264.stderr - testsuite/tests/typecheck/should_fail/all.T - utils/check-exact/ExactPrint.hs - utils/haddock/haddock-api/src/Haddock/Convert.hs - utils/haddock/haddock-test/src/Test/Haddock.hs - utils/haddock/html-test/ref/Bug1004.html - utils/haddock/html-test/ref/Bug1050.html - + utils/haddock/html-test/ref/Bug26246.html - utils/haddock/html-test/ref/Bug85.html - utils/haddock/html-test/ref/Bug923.html - utils/haddock/html-test/ref/BundledPatterns.html - utils/haddock/html-test/ref/BundledPatterns2.html - utils/haddock/html-test/ref/ConstructorPatternExport.html - utils/haddock/html-test/ref/GADTRecords.html - utils/haddock/html-test/ref/LinearTypes.html - utils/haddock/html-test/ref/PromotedTypes.html - + utils/haddock/html-test/src/Bug26246.hs - utils/haddock/hypsrc-test/ref/src/Classes.html - utils/haddock/hypsrc-test/ref/src/Quasiquoter.html - utils/haddock/latex-test/ref/LinearTypes/LinearTypes.tex - utils/iserv/iserv.cabal.in The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/26977a1c28287cebaa22167fc0a5f7… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/26977a1c28287cebaa22167fc0a5f7… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26548] Try making Reduction strict in its Coercion
by Simon Peyton Jones (＠simonpj) 26 Nov '25

26 Nov '25

Simon Peyton Jones pushed to branch wip/T26548 at Glasgow Haskell Compiler / GHC Commits: 57dcbdf7 by Simon Peyton Jones at 2025-11-26T09:34:55+00:00 Try making Reduction strict in its Coercion Just an experiment. The comment says -- N.B. the 'Coercion' field must be lazy: see for instance -- GHC.Tc.Solver.Rewrite.rewrite_tyvar2 which returns an error in the 'Coercion' -- field when dealing with a Derived constraint (which is OK as this Coercion -- gets ignored later). We might want to revisit the strictness once Deriveds -- are removed. But Deriveds are in the rear view mirror. - - - - - 1 changed file: - compiler/GHC/Core/Reduction.hs Changes: ===================================== compiler/GHC/Core/Reduction.hs ===================================== @@ -94,7 +94,7 @@ but in fact `reductionOriginalType` is very seldom used, so it's not worth it. -- See Note [The Reduction type]. data Reduction = Reduction - { reductionCoercion :: Coercion + { reductionCoercion :: !Coercion , reductionReducedType :: !Type } -- N.B. the 'Coercion' field must be lazy: see for instance GHC.Tc.Solver.Rewrite.rewrite_tyvar2 View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/57dcbdf7cf9f0b443d5dd97c1603517… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/57dcbdf7cf9f0b443d5dd97c1603517… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/int-index/imp-exp-whole-namespace] Namespace-specified wildcards in import/export lists (#25901)
by Vladislav Zavialov (＠int-index) 26 Nov '25

26 Nov '25

Vladislav Zavialov pushed to branch wip/int-index/imp-exp-whole-namespace at Glasgow Haskell Compiler / GHC Commits: 58f7734f by Vladislav Zavialov at 2025-11-26T03:52:03+03:00 Namespace-specified wildcards in import/export lists (#25901) This change adds support for top-level namespace-specified wildcards `type ..` and `data ..` to import and export lists. Examples: import M (type ..) -- imports all type and class constructors from M import M (data ..) -- imports all data constructors and terms from M module M (type .., f) where -- exports all type and class constructors defined in M, -- plus the function 'f' The primary intended usage of this feature is in combination with module aliases, allowing namespace disambiguation: import Data.Proxy as T (type ..) -- T.Proxy is unambiguously the type constructor import Data.Proxy as D (data ..) -- D.Proxy is unambiguously the data constructor The patch accounts for the interactions of wildcards with: * Imports with `hiding` clauses * Import warnings -Wunused-imports, -Wdodgy-imports * Export warnings -Wduplicate-exports, -Wdodgy-exports Summary of the changes: 1. Move the NamespaceSpecifier type from GHC.Hs.Binds to GHC.Hs.Basic, making it possible to use it in more places in the AST. 2. Extend the AST (type: IE) with a representation of `..`, `type ..`, and `data ..` (constructor: IEWholeNamespace). Per the proposal, the plain `..` is always rejected with a dedicated error message. 3. Extend the grammar in Parser.y with productions for `..`, `type ..`, and `data ..` in both import and export lists. 4. Implement wildcard imports by updating the `filterImports` function in GHC.Rename.Names; the logic for IEWholeNamespace is roughly modeled after the Nothing (no explicit import list) case. 5. Implement wildcard exports by updating the `exports_from_avail` function in GHC.Tc.Gen.Export; the logic for IEWholeNamespace is closely modeled after the IEModuleContents case. 6. Refactor and extend diagnostics to report the new warnings and errors. See PsErrPlainWildcardImport, DodgyImportsWildcard, PsErrPlainWildcardExport, DodgyExportsWildcard, TcRnDupeWildcardExport. Note that this patch is specifically about top-level import/export items. Subordinate import/export items are left unchanged. - - - - - 79 changed files: - compiler/GHC/Hs/Basic.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/HsToCore/Docs.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/Errors/Types.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Hint.hs - compiler/GHC/Types/Hint/Ppr.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/Language/Haskell/Syntax/ImpExp.hs - docs/users_guide/9.16.1-notes.rst - docs/users_guide/exts/explicit_namespaces.rst - + testsuite/tests/module/T25901_exp_plain_wc.hs - + testsuite/tests/module/T25901_exp_plain_wc.stderr - + testsuite/tests/module/T25901_imp_plain_wc.hs - + testsuite/tests/module/T25901_imp_plain_wc.stderr - testsuite/tests/module/all.T - + testsuite/tests/rename/should_compile/T25901_exp_1.hs - + testsuite/tests/rename/should_compile/T25901_exp_1_helper.hs - + testsuite/tests/rename/should_compile/T25901_exp_2.hs - + testsuite/tests/rename/should_compile/T25901_exp_2_helper.hs - + testsuite/tests/rename/should_compile/T25901_imp_hq.hs - + testsuite/tests/rename/should_compile/T25901_imp_hu.hs - + testsuite/tests/rename/should_compile/T25901_imp_sq.hs - + testsuite/tests/rename/should_compile/T25901_imp_su.hs - testsuite/tests/rename/should_compile/all.T - + testsuite/tests/rename/should_fail/T25901_exp_fail_1.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_1.stderr - + testsuite/tests/rename/should_fail/T25901_exp_fail_1_helper.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_2.hs - + testsuite/tests/rename/should_fail/T25901_exp_fail_2.stderr - + testsuite/tests/rename/should_fail/T25901_exp_fail_2_helper.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_5.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_5.stderr - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_6.hs - + testsuite/tests/rename/should_fail/T25901_imp_hq_fail_6.stderr - + testsuite/tests/rename/should_fail/T25901_imp_hu_fail_4.hs - + testsuite/tests/rename/should_fail/T25901_imp_hu_fail_4.stderr - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_2.hs - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_2.stderr - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_3.hs - + testsuite/tests/rename/should_fail/T25901_imp_sq_fail_3.stderr - + testsuite/tests/rename/should_fail/T25901_imp_su_fail_1.hs - + testsuite/tests/rename/should_fail/T25901_imp_su_fail_1.stderr - testsuite/tests/rename/should_fail/all.T - + testsuite/tests/warnings/should_compile/T25901_exp_dodgy.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dodgy.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_1.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_1.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_2.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_2.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_3.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_3.stderr - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_4.hs - + testsuite/tests/warnings/should_compile/T25901_exp_dup_wc_4.stderr - + testsuite/tests/warnings/should_compile/T25901_helper_1.hs - + testsuite/tests/warnings/should_compile/T25901_helper_2.hs - + testsuite/tests/warnings/should_compile/T25901_helper_3.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_1.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_1.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_2.hs - + testsuite/tests/warnings/should_compile/T25901_imp_dodgy_2.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_1.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_1.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_2.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_2.stderr - + testsuite/tests/warnings/should_compile/T25901_imp_unused_3.hs - + testsuite/tests/warnings/should_compile/T25901_imp_unused_3.stderr - testsuite/tests/warnings/should_compile/all.T - utils/check-exact/ExactPrint.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/58f7734f571fe7a09689c43ce6c6466… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/58f7734f571fe7a09689c43ce6c6466… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/spj-apporv-Oct24] hopefully fixes all the error messages
by Apoorv Ingle (＠ani) 25 Nov '25

25 Nov '25

Apoorv Ingle pushed to branch wip/spj-apporv-Oct24 at Glasgow Haskell Compiler / GHC Commits: 302422b4 by Apoorv Ingle at 2025-11-25T17:42:57-06:00 hopefully fixes all the error messages - - - - - 3 changed files: - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Match.hs Changes: ===================================== compiler/GHC/Tc/Gen/App.hs ===================================== @@ -536,7 +536,7 @@ checkResultTy :: DeepSubsumptionFlag -- expose foralls, but maybe not /deeply/ instantiated -> ExpRhoType -- Expected type; this is deeply skolemised -> TcM HsWrapper -checkResultTy ds_flag rn_expr (fun, _) _inst_args app_res_rho (Infer inf_res) +checkResultTy ds_flag rn_expr _ _ app_res_rho (Infer inf_res) = fillInferResult ds_flag (exprCtOrigin rn_expr) app_res_rho inf_res checkResultTy ds_flag rn_expr (tc_fun, fun_loc) inst_args app_res_rho (Check res_ty) ===================================== compiler/GHC/Tc/Gen/Expr.hs ===================================== @@ -335,7 +335,7 @@ tcExpr e@(HsLit x lit) res_ty ; tcWrapResult e (HsLit x (convertLit lit)) lit_ty res_ty } tcExpr (HsPar x expr) res_ty - = do { expr' <- tcMonoLExpr expr res_ty + = do { expr' <- tcMonoLExprNC expr res_ty ; return (HsPar x expr') } tcExpr (HsPragE x prag expr) res_ty ===================================== compiler/GHC/Tc/Gen/Match.hs ===================================== @@ -42,7 +42,7 @@ import GHC.Prelude import {-# SOURCE #-} GHC.Tc.Gen.Expr( tcSyntaxOp, tcInferRho, tcInferRhoFRRNC , tcMonoLExprNC, tcMonoLExpr, tcExpr , tcCheckMonoExpr, tcCheckMonoExprNC - , tcCheckPolyExpr, tcPolyExpr ) + , tcCheckPolyExpr, tcPolyLExpr ) import GHC.Rename.Utils ( bindLocalNames ) import GHC.Tc.Errors.Types @@ -420,15 +420,10 @@ tcDoStmts mDoExpr ss@(L _ stmts) res_ty } tcBody :: LHsExpr GhcRn -> ExpRhoType -> TcM (LHsExpr GhcTc) -tcBody (L lspan e) res_ty - = L lspan <$> - do { traceTc "tcBody" (ppr res_ty) - ; setSrcSpanA lspan $ - addErrCtxt (ExprCtxt e) $ - -- We want the right hand side of a match or an equation - -- to always get printed in the error context - tcPolyExpr e res_ty - } +tcBody body res_ty + = do { traceTc "tcBody" (ppr res_ty) + ; tcPolyLExpr body res_ty + } {- ************************************************************************ View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/302422b43e271908fd6c3ebb3ea59f8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/302422b43e271908fd6c3ebb3ea59f8… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/spj-apporv-Oct24] hopefully fixes all the error messages
by Apoorv Ingle (＠ani) 25 Nov '25

25 Nov '25

Apoorv Ingle pushed to branch wip/spj-apporv-Oct24 at Glasgow Haskell Compiler / GHC Commits: f42facf3 by Apoorv Ingle at 2025-11-25T17:36:39-06:00 hopefully fixes all the error messages - - - - - 2 changed files: - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Match.hs Changes: ===================================== compiler/GHC/Tc/Gen/Expr.hs ===================================== @@ -335,7 +335,7 @@ tcExpr e@(HsLit x lit) res_ty ; tcWrapResult e (HsLit x (convertLit lit)) lit_ty res_ty } tcExpr (HsPar x expr) res_ty - = do { expr' <- tcMonoLExpr expr res_ty + = do { expr' <- tcMonoLExprNC expr res_ty ; return (HsPar x expr') } tcExpr (HsPragE x prag expr) res_ty ===================================== compiler/GHC/Tc/Gen/Match.hs ===================================== @@ -42,7 +42,7 @@ import GHC.Prelude import {-# SOURCE #-} GHC.Tc.Gen.Expr( tcSyntaxOp, tcInferRho, tcInferRhoFRRNC , tcMonoLExprNC, tcMonoLExpr, tcExpr , tcCheckMonoExpr, tcCheckMonoExprNC - , tcCheckPolyExpr, tcPolyExpr ) + , tcCheckPolyExpr, tcPolyLExpr ) import GHC.Rename.Utils ( bindLocalNames ) import GHC.Tc.Errors.Types @@ -420,15 +420,10 @@ tcDoStmts mDoExpr ss@(L _ stmts) res_ty } tcBody :: LHsExpr GhcRn -> ExpRhoType -> TcM (LHsExpr GhcTc) -tcBody (L lspan e) res_ty - = L lspan <$> - do { traceTc "tcBody" (ppr res_ty) - ; setSrcSpanA lspan $ - addErrCtxt (ExprCtxt e) $ - -- We want the right hand side of a match or an equation - -- to always get printed in the error context - tcPolyExpr e res_ty - } +tcBody body res_ty + = do { traceTc "tcBody" (ppr res_ty) + ; tcPolyLExpr body res_ty + } {- ************************************************************************ View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f42facf387a0ee107782baf225a9b6b… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/f42facf387a0ee107782baf225a9b6b… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/spj-apporv-Oct24] accept a test case. Remove HsPar as a special case from add_expr_ctxt
by Apoorv Ingle (＠ani) 25 Nov '25

25 Nov '25

Apoorv Ingle pushed to branch wip/spj-apporv-Oct24 at Glasgow Haskell Compiler / GHC Commits: ac1c8658 by Apoorv Ingle at 2025-11-25T16:57:11-06:00 accept a test case. Remove HsPar as a special case from add_expr_ctxt - - - - - 3 changed files: - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/Match.hs - testsuite/tests/indexed-types/should_fail/T1897b.stderr Changes: ===================================== compiler/GHC/Tc/Gen/Head.hs ===================================== @@ -1091,14 +1091,8 @@ add_expr_ctxt e thing_inside -- when we don't want to say "In the expression: _", -- because it is mentioned in the error message itself - HsPar{} -> thing_inside - -- We don't want to say 'In the expression (e)', - -- we just want to say 'In the expression, 'e' - -- which will be handeled by the recursive call in thing_inside - ExprWithTySig _ (L _ e') _ - | XExpr (ExpandedThingRn o _) <- e' -> addExpansionErrCtxt o (ExprCtxt e) - thing_inside + | XExpr (ExpandedThingRn o _) <- e' -> addExpansionErrCtxt o (ExprCtxt e) thing_inside -- There is a special case for expressions with signatures to avoid having too verbose -- error context. So here we flip the ErrCtxt state to expanded if the expression is expanded. -- c.f. RecordDotSyntaxFail9 ===================================== compiler/GHC/Tc/Gen/Match.hs ===================================== @@ -426,7 +426,7 @@ tcBody (L lspan e) res_ty ; setSrcSpanA lspan $ addErrCtxt (ExprCtxt e) $ -- We want the right hand side of a match or an equation - -- to always get printed + -- to always get printed in the error context tcPolyExpr e res_ty } ===================================== testsuite/tests/indexed-types/should_fail/T1897b.stderr ===================================== @@ -1,14 +1,14 @@ T1897b.hs:16:1: error: [GHC-83865] - • Couldn't match type: Depend b0 - with: Depend b - Expected: t (Depend b) -> Bool - Actual: t (Depend b0) -> Bool + • Couldn't match type: Depend a0 + with: Depend a + Expected: t (Depend a) -> Bool + Actual: t (Depend a0) -> Bool Note: ‘Depend’ is a non-injective type family. - The type variable ‘b0’ is ambiguous + The type variable ‘a0’ is ambiguous • In the ambiguity check for the inferred type for ‘isValid’ To defer the ambiguity check to use sites, enable AllowAmbiguousTypes When checking the inferred type - isValid :: forall {t :: * -> *} {b}. - (Foldable t, Bug b) => - t (Depend b) -> Bool + isValid :: forall {t :: * -> *} {a}. + (Foldable t, Bug a) => + t (Depend a) -> Bool View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/ac1c86588be8d88f4fe08c520960555… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/ac1c86588be8d88f4fe08c520960555… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/amg/castz] 4 commits: Accept output change for prog-mhu002c
by Adam Gundry (＠adamgundry) 25 Nov '25

25 Nov '25

Adam Gundry pushed to branch wip/amg/castz at Glasgow Haskell Compiler / GHC Commits: f9292660 by Adam Gundry at 2025-11-25T14:43:11+00:00 Accept output change for prog-mhu002c - - - - - b5ebc105 by Adam Gundry at 2025-11-25T19:15:27+00:00 Fix forall visibility bugs - - - - - 6aa2899f by Adam Gundry at 2025-11-25T19:32:01+00:00 Optimise ZCoercion in simplifier - - - - - 5afbb4f8 by Adam Gundry at 2025-11-25T20:48:39+00:00 Experiment with heuristic so zonker zaps only large casts - - - - - 5 changed files: - compiler/GHC/Core/Coercion.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Tc/Zonk/Type.hs - testsuite/tests/ghci/prog-mhu002/prog-mhu002c.stdout Changes: ===================================== compiler/GHC/Core/Coercion.hs ===================================== @@ -984,12 +984,13 @@ mkForAllCo v visL visR kind_co co | otherwise = mk_forall_co v visL visR kind_co co -mkForAllCastCo :: HasDebugCallStack => TyCoVar -> ForAllTyFlag -> ForAllTyFlag - -> CastCoercion -> CastCoercion -mkForAllCastCo v visL visR cco = case cco of +mkForAllCastCo :: HasDebugCallStack => Role -> TyCoVar -> ForAllTyFlag -> ForAllTyFlag + -> Type -> CastCoercion -> CastCoercion +mkForAllCastCo r v visL visR ty cco = case cco of CCoercion co -> CCoercion (mkForAllCo v visL visR MRefl co) - ZCoercion ty cos -> ZCoercion (mkTyCoForAllTy v visL ty) cos - ReflCastCo -> ReflCastCo + ZCoercion ty cos -> ZCoercion (mkTyCoForAllTy v visR ty) cos + ReflCastCo | visL `eqForAllVis` visR -> ReflCastCo + | otherwise -> CCoercion (mk_forall_co v visL visR MRefl (mkReflCo r ty)) -- mkForAllVisCos [tv{vis}] constructs a cast -- forall tv. res ~R# forall tv{vis} res`. @@ -1816,7 +1817,7 @@ mkPiCastCo :: Role -> Var -> CastCoercion -> CastCoercion mkPiCastCo _ _ ReflCastCo = ReflCastCo mkPiCastCo r v (CCoercion co) = CCoercion (mkPiCo r v co) mkPiCastCo _ v (ZCoercion ty cos) - | isTyVar v = ZCoercion (mkForAllTy (Bndr v vis) ty) cos + | isTyVar v = ZCoercion (mkTyCoForAllTy v vis ty) cos | otherwise = ZCoercion (mkFunctionType (idMult v) (varType v) ty) cos where vis = coreTyLamForAllTyFlag ===================================== compiler/GHC/Core/Opt/Arity.hs ===================================== @@ -2359,12 +2359,12 @@ mkEtaWW orig_oss ppr_orig_expr in_scope orig_ty -- with an explicit lambda having a non-function type mkEtaForAllMCo :: ForAllTyBinder -> Type -> CastCoercion -> CastCoercion -mkEtaForAllMCo bdnr@(Bndr tcv vis) ty mco +mkEtaForAllMCo (Bndr tcv vis) ty mco = case mco of ReflCastCo | vis == coreTyLamForAllTyFlag -> ReflCastCo | otherwise -> mk_fco (mkRepReflCo ty) CCoercion co -> mk_fco co - ZCoercion tyR cos -> ZCoercion (mkForAllTy bdnr tyR) cos + ZCoercion tyR cos -> ZCoercion (mkTyCoForAllTy tcv coreTyLamForAllTyFlag tyR) cos where mk_fco co = CCoercion (mkForAllCo tcv vis coreTyLamForAllTyFlag MRefl co) -- coreTyLamForAllTyFlag: See Note [The EtaInfo mechanism], particularly @@ -2723,7 +2723,7 @@ tryEtaReduce rec_ids bndrs body eval_sd -- Float app ticks: \x -> Tick t (e x) ==> Tick t e go (b : bs) (App fun arg) co - | Just (co', ticks) <- ok_arg b arg co (exprType fun) + | Just (co', ticks) <- ok_arg b arg co (exprType fun) (exprType (App fun arg)) = fmap (flip (foldr mkTick) ticks) $ go bs fun co' -- Float arg ticks: \x -> e (Tick t x) ==> Tick t e @@ -2798,15 +2798,16 @@ tryEtaReduce rec_ids bndrs body eval_sd -> CastCoercion -- Of kind (t1~t2) -> Type -- Type (arg_t -> t1) of the function -- to which the argument is supplied + -> Type -- Type t1 of the result (AMG TODO: avoid needing to pass this?) -> Maybe (CastCoercion -- Of type (arg_t -> t1 ~ bndr_t -> t2) -- (and similarly for tyvars, coercion args) , [CoreTickish]) -- See Note [Eta reduction with casted arguments] - ok_arg bndr (Type arg_ty) co fun_ty + ok_arg bndr (Type arg_ty) co fun_ty res_ty | Just tv <- getTyVar_maybe arg_ty , bndr == tv = case splitForAllForAllTyBinder_maybe fun_ty of Just (Bndr _ vis, _) -> Just (fco, []) - where !fco = mkForAllCastCo tv vis coreTyLamForAllTyFlag co + where !fco = mkForAllCastCo Representational tv vis coreTyLamForAllTyFlag res_ty co -- The lambda we are eta-reducing always has visibility -- 'coreTyLamForAllTyFlag' which may or may not match -- the visibility on the inner function (#24014) @@ -2814,24 +2815,24 @@ tryEtaReduce rec_ids bndrs body eval_sd (text "fun:" <+> ppr bndr $$ text "arg:" <+> ppr arg_ty $$ text "fun_ty:" <+> ppr fun_ty) - ok_arg bndr (Var v) co fun_ty + ok_arg bndr (Var v) co fun_ty _ | bndr == v , let mult = idMult bndr , Just (_af, fun_mult, _, _) <- splitFunTy_maybe fun_ty , mult `eqType` fun_mult -- There is no change in multiplicity, otherwise we must abort = Just (mkFunResCastCo Representational bndr co, []) - ok_arg bndr (Cast e co_arg) co fun_ty + ok_arg bndr (Cast e co_arg) co fun_ty _ | (ticks, Var v) <- stripTicksTop tickishFloatable e , Just (_, fun_mult, _, res_ty) <- splitFunTy_maybe fun_ty , bndr == v , fun_mult `eqType` idMult bndr - = Just (mkFunCastCoNoFTF Representational fun_mult (castCoercionRKind (exprType e) co_arg) (mkSymCastCo (exprType e) co_arg) res_ty co, ticks) -- TODO check types + = Just (mkFunCastCoNoFTF Representational fun_mult (castCoercionRKind (exprType e) co_arg) (mkSymCastCo (exprType e) co_arg) res_ty co, ticks) -- The simplifier combines multiple casts into one, -- so we can have a simple-minded pattern match here - ok_arg bndr (Tick t arg) co fun_ty - | tickishFloatable t, Just (co', ticks) <- ok_arg bndr arg co fun_ty + ok_arg bndr (Tick t arg) co fun_ty res_ty + | tickishFloatable t, Just (co', ticks) <- ok_arg bndr arg co fun_ty res_ty = Just (co', t:ticks) - ok_arg _ _ _ _ = Nothing + ok_arg _ _ _ _ _ = Nothing -- | Can we eta-reduce the given function -- See Note [Eta reduction soundness], criteria (B), (J), and (W). ===================================== compiler/GHC/Core/Opt/Simplify/Iteration.hs ===================================== @@ -28,7 +28,7 @@ import GHC.Core.Make ( FloatBind, mkImpossibleExpr, castBottomExpr ) import qualified GHC.Core.Make import GHC.Core.Coercion hiding ( substCo, substCoVar ) import GHC.Core.Reduction -import GHC.Core.Coercion.Opt ( optCoercion ) +import GHC.Core.Coercion.Opt ( optCoercion, optCastCoercion ) import GHC.Core.FamInstEnv ( FamInstEnv, topNormaliseType_maybe ) import GHC.Core.DataCon import GHC.Core.Opt.Stats ( Tick(..) ) @@ -1545,7 +1545,7 @@ rebuild_go env expr cont -> rebuild_go env (mkCastCo expr co') cont -- NB: mkCast implements the (Coercion co |> g) optimisation where - co' = optOutCastCoercion env co opt + co' = optOutCoercion env (exprType expr) co opt Select { sc_bndr = bndr, sc_alts = alts, sc_env = se, sc_cont = cont } -> rebuildCase (se `setInScopeFromE` env) expr bndr alts cont @@ -1674,17 +1674,11 @@ on each successive composition -- that's at least quadratic. So: -} -optOutCastCoercion :: SimplEnvIS -> OutCastCoercion -> Bool -> OutCastCoercion -optOutCastCoercion env cco already_optimised = case cco of - ReflCastCo -> ReflCastCo - CCoercion co -> CCoercion (optOutCoercion env co already_optimised) - ZCoercion{} -> cco - -optOutCoercion :: SimplEnvIS -> OutCoercion -> Bool -> OutCoercion +optOutCoercion :: SimplEnvIS -> Type -> OutCastCoercion -> Bool -> OutCastCoercion -- See Note [Avoid re-simplifying coercions] -optOutCoercion env co already_optimised +optOutCoercion env ty co already_optimised | already_optimised = co -- See Note [Avoid re-simplifying coercions] - | otherwise = optCoercion opts empty_subst co + | otherwise = optCastCoercion opts empty_subst ty co where empty_subst = mkEmptySubst (seInScope env) opts = seOptCoercionOpts env @@ -1732,7 +1726,7 @@ simplCast env body co0 cont0 , sc_dup = dup, sc_cont = tail , sc_hole_ty = fun_ty }) | not co_is_opt -- pushCoValArg duplicates the coercion, so optimise first - = addCoerce tyL (optOutCastCoercion (zapSubstEnv env) co co_is_opt) True cont + = addCoerce tyL (optOutCoercion (zapSubstEnv env) tyL co co_is_opt) True cont | Just (_, m_co1, res_ty, m_co2) <- pushCastCoValArg tyL co = {-#SCC "addCoerce-pushCoValArg" #-} @@ -3886,7 +3880,7 @@ mkDupableContWithDmds _ _ (Stop {}) = panic "mkDupableCont" -- Handled by pr mkDupableContWithDmds env dmds (CastIt { sc_co = co, sc_hole_ty = ty, sc_opt = opt, sc_cont = cont }) = do { (floats, cont') <- mkDupableContWithDmds env dmds cont - ; return (floats, CastIt { sc_co = optOutCastCoercion env co opt + ; return (floats, CastIt { sc_co = optOutCoercion env ty co opt , sc_hole_ty = ty , sc_opt = True, sc_cont = cont' }) } -- optOutCoercion: see Note [Avoid re-simplifying coercions] ===================================== compiler/GHC/Tc/Zonk/Type.hs ===================================== @@ -1862,9 +1862,10 @@ zonkEvTerm (EvExpr e) = EvExpr <$> zonkCoreExpr e zonkEvTerm (EvCastExpr e (CCoercion co) co_res_ty) = do { zap_casts <- hasZapCasts <$> lift getDynFlags - ; co_res_ty' <- zonkTcTypeToTypeX co_res_ty - ; if zap_casts - then EvCastExpr <$> zonkCoreExpr e <*> (ZCoercion co_res_ty' <$> zonkShallowCoVarsOfCo co) <*> pure co_res_ty' + ; if zap_casts && coercionSize co > typeSize co_res_ty -- AMG TODO: experimental heuristic + then do { co_res_ty' <- zonkTcTypeToTypeX co_res_ty + ; EvCastExpr <$> zonkCoreExpr e <*> (ZCoercion co_res_ty' <$> zonkShallowCoVarsOfCo co) <*> pure co_res_ty' + } else EvExpr <$> zonkCoreExpr (Cast e (CCoercion co)) } zonkEvTerm ev@(EvCastExpr _ (ZCoercion{}) _) ===================================== testsuite/tests/ghci/prog-mhu002/prog-mhu002c.stdout ===================================== @@ -15,6 +15,7 @@ other dynamic, non-language, flag settings: -fshow-warning-groups -fprefer-byte-code -fbreak-points + -fno-zap-casts warning settings: -Wpattern-namespace-specifier === :set @@ -34,6 +35,7 @@ other dynamic, non-language, flag settings: -fshow-warning-groups -fprefer-byte-code -fbreak-points + -fno-zap-casts warning settings: -Wpattern-namespace-specifier Unit ID: b-0.0.0 @@ -51,6 +53,7 @@ other dynamic, non-language, flag settings: -fshow-warning-groups -fprefer-byte-code -fbreak-points + -fno-zap-casts warning settings: -Wpattern-namespace-specifier Unit ID: c-0.0.0 @@ -68,6 +71,7 @@ other dynamic, non-language, flag settings: -fshow-warning-groups -fprefer-byte-code -fbreak-points + -fno-zap-casts warning settings: -Wpattern-namespace-specifier Unit ID: d-0.0.0 @@ -85,5 +89,6 @@ other dynamic, non-language, flag settings: -fshow-warning-groups -fprefer-byte-code -fbreak-points + -fno-zap-casts warning settings: -Wpattern-namespace-specifier View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/307ee28a3679bfdece77c6868a7da8… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/307ee28a3679bfdece77c6868a7da8… You're receiving this email because of your account on gitlab.haskell.org.

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