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* compiler: Use compact representation for SourceTextZubin Duggal2023-05-162-3/+5
| | | | | | | | | | | | SourceText is serialized along with INLINE pragmas into interface files. Many of these SourceTexts are identical, for example "{-# INLINE#". When deserialized, each such SourceText was previously expanded out into a [Char], which is highly wasteful of memory, and each such instance of the text would allocate an independent list with its contents as deserializing breaks any sharing that might have existed. Instead, we use a `FastString` to represent these, so that each instance unique text will be interned and stored in a memory efficient manner.
* Migrate errors to diagnostics in GHC.Tc.Modulesheaf2023-05-151-5/+5
| | | | | | | | | | | | | | | | | | | | This commit migrates the errors in GHC.Tc.Module to use the new diagnostic infrastructure. It required a significant overhaul of the compatibility checks between an hs-boot or signature module and its implementation; we now use a Writer monad to accumulate errors; see the BootMismatch datatype in GHC.Tc.Errors.Types, with its panoply of subtypes. For the sake of readability, several local functions inside the 'checkBootTyCon' function were split off into top-level functions. We split off GHC.Types.HscSource into a "boot or sig" vs "normal hs file" datatype, as this mirrors the logic in several other places where we want to treat hs-boot and hsig files in a similar fashion. This commit also refactors the Backpack checks for type synonyms implementing abstract data, to correctly reject implementations that contain qualified or quantified types (this fixes #23342 and #23344).
* Split DynFlags structure into own moduleOleg Grenrus2023-05-153-3/+3
| | | | | This will allow to make command line parsing to depend on diagnostic system (which depends on dynflags)
* Fix bad multiplicity role in tyConAppFunCo_maybesheaf2023-05-133-4/+10
| | | | | | | | | | The function tyConAppFunCo_maybe produces a multiplicity coercion for the multiplicity argument of the function arrow, except that it could be at the wrong role if asked to produce a representational coercion. We fix this by using the 'funRole' function, which computes the right roles for arguments to the function arrow TyCon. Fixes #23386
* Use the eager unifier in the constraint solverSimon Peyton Jones2023-05-128-58/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch continues the refactoring of the constraint solver described in #23070. The Big Deal in this patch is to call the regular, eager unifier from the constraint solver, when we want to create new equalities. This replaces the existing, unifyWanted which amounted to yet-another-unifier, so it reduces duplication of a rather subtle piece of technology. See * Note [The eager unifier] in GHC.Tc.Utils.Unify * GHC.Tc.Solver.Monad.wrapUnifierTcS I did lots of other refactoring along the way * I simplified the treatment of right hand sides that contain CoercionHoles. Now, a constraint that contains a hetero-kind CoercionHole is non-canonical, and cannot be used for rewriting or unification alike. This required me to add the ch_hertero_kind flag to CoercionHole, with consequent knock-on effects. See wrinkle (2) of `Note [Equalities with incompatible kinds]` in GHC.Tc.Solver.Equality. * I refactored the StopOrContinue type to add StartAgain, so that after a fundep improvement (for example) we can simply start the pipeline again. * I got rid of the unpleasant (and inefficient) rewriterSetFromType/Co functions. With Richard I concluded that they are never needed. * I discovered Wrinkle (W1) in Note [Wanteds rewrite Wanteds] in GHC.Tc.Types.Constraint, and therefore now prioritise non-rewritten equalities. Quite a few error messages change, I think always for the better. Compiler runtime stays about the same, with one outlier: a 17% improvement in T17836 Metric Decrease: T17836 T18223
* Move checkAxInstCo to GHC.Core.LintAdam Gundry2023-05-122-57/+64
| | | | | | | | A consequence of the previous change is that checkAxInstCo is no longer called during coercion optimization, so it can be moved back where it belongs. Also includes some edits to Note [Conflict checking with AxiomInstCo] as suggested by @simonpj.
* Less coercion optimization for non-newtype axiomsAdam Gundry2023-05-121-5/+85
| | | | | | | | | | | | | | | | | | See Note [Push transitivity inside newtype axioms only] for an explanation of the change here. This change substantially improves the performance of coercion optimization for programs involving transitive type family reductions. ------------------------- Metric Decrease: CoOpt_Singletons LargeRecord T12227 T12545 T13386 T15703 T5030 T8095 -------------------------
* Fix coercion optimisation for SelCo (#23362)Krzysztof Gogolewski2023-05-121-3/+12
| | | | | | setNominalRole_maybe is supposed to output a nominal coercion. In the SelCo case, it was not updating the stored role to Nominal, causing #23362.
* Don't panic in mkNewTyConRhssheaf2023-05-121-1/+1
| | | | | | | | | | | | | This function could come across invalid newtype constructors, as we only perform validity checking of newtypes once we are outside the knot-tied typechecking loop. This patch changes this function to fake up a stub type in the case of an invalid newtype, instead of panicking. This patch also changes "checkNewDataCon" so that it reports as many errors as possible at once. Fixes #23308
* Add fused multiply-add instructionssheaf2023-05-111-0/+156
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds eight new primops that fuse a multiplication and an addition or subtraction: - `{fmadd,fmsub,fnmadd,fnmsub}{Float,Double}#` fmadd x y z is x * y + z, computed with a single rounding step. This patch implements code generation for these primops in the following backends: - X86, AArch64 and PowerPC NCG, - LLVM - C WASM uses the C implementation. The primops are unsupported in the JavaScript backend. The following constant folding rules are also provided: - compute a * b + c when a, b, c are all literals, - x * y + 0 ==> x * y, - ±1 * y + z ==> z ± y and x * ±1 + z ==> z ± x. NB: the constant folding rules incorrectly handle signed zero. This is a known limitation with GHC's floating-point constant folding rules (#21227), which we hope to resolve in the future.
* linear types: Don't add external names to the usage envKrzysztof Gogolewski2023-05-042-4/+10
| | | | This has no observable effect, but avoids storing useless data.
* Add the Unsatisfiable classsheaf2023-04-291-4/+7
| | | | | | | | | This commit implements GHC proposal #433, adding the Unsatisfiable class to the GHC.TypeError module. This provides an alternative to TypeError for which error reporting is more predictable: we report it when we are reporting unsolved Wanted constraints. Fixes #14983 #16249 #16906 #18310 #20835
* DmdAnal: Unleash demand signatures of free RULE and unfolding binders (#23208)Sebastian Graf2023-04-262-92/+132
| | | | | | | | | | | | | | | | | | | | | | | | | | | In #23208 we observed that the demand signature of a binder occuring in a RULE wasn't unleashed, leading to a transitively used binder being discarded as absent. The solution was to use the same code path that we already use for handling exported bindings. See the changes to `Note [Absence analysis for stable unfoldings and RULES]` for more details. I took the chance to factor out the old notion of a `PlusDmdArg` (a pair of a `VarEnv Demand` and a `Divergence`) into `DmdEnv`, which fits nicely into our existing framework. As a result, I had to touch quite a few places in the code. This refactoring exposed a few small bugs around correct handling of bottoming demand environments. As a result, some strictness signatures now mention uniques that weren't there before which caused test output changes to T13143, T19969 and T22112. But these tests compared whole -ddump-simpl listings which is a very fragile thing to begin with. I changed what exactly they test for based on the symptoms in the corresponding issues. There is a single regression in T18894 because we are more conservative around stable unfoldings now. Unfortunately it is not easily fixed; let's wait until there is a concrete motivation before invest more time. Fixes #23208.
* Misc cleanupKrzysztof Gogolewski2023-04-175-25/+23
| | | | | | - Use dedicated list functions - Make cloneBndrs and cloneRecIdBndrs monadic - Fix invalid haddock comments in libraries/base
* Transfer DFunId_ness onto specialised bindingsSimon Peyton Jones2023-04-161-41/+78
| | | | | | | | | | | | | | | | | | | | Whether a binding is a DFunId or not has consequences for the `-fdicts-strict` flag, essentially if we are doing demand analysis for a DFunId then `-fdicts-strict` does not apply because the constraint solver can create recursive groups of dictionaries. In #22549 this was fixed for the "normal" case, see Note [Do not strictify the argument dictionaries of a dfun]. However the loop still existed if the DFunId was being specialised. The problem was that the specialiser would specialise a DFunId and turn it into a VanillaId and so the demand analyser didn't know to apply special treatment to the binding anymore and the whole recursive group was optimised to bottom. The solution is to transfer over the DFunId-ness of the binding in the specialiser so that the demand analyser knows not to apply the `-fstrict-dicts`. Fixes #22549
* Major refactor in the handling of equality constraintsSimon Peyton Jones2023-04-146-67/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This MR substantially refactors the way in which the constraint solver deals with equality constraints. The big thing is: * Intead of a pipeline in which we /first/ canonicalise and /then/ interact (the latter including performing unification) the two steps are more closely integreated into one. That avoids the current rather indirect communication between the two steps. The proximate cause for this refactoring is fixing #22194, which involve solving [W] alpha[2] ~ Maybe (F beta[4]) by doing this: alpha[2] := Maybe delta[2] [W] delta[2] ~ F beta[4] That is, we don't promote beta[4]! This is very like introducing a cycle breaker, and was very awkward to do before, but now it is all nice. See GHC.Tc.Utils.Unify Note [Promotion and level-checking] and Note [Family applications in canonical constraints]. The big change is this: * Several canonicalisation checks (occurs-check, cycle-breaking, checking for concreteness) are combined into one new function: GHC.Tc.Utils.Unify.checkTyEqRhs This function is controlled by `TyEqFlags`, which says what to do for foralls, type families etc. * `canEqCanLHSFinish` now sees if unification is possible, and if so, actually does it: see `canEqCanLHSFinish_try_unification`. There are loads of smaller changes: * The on-the-fly unifier `GHC.Tc.Utils.Unify.unifyType` has a cheap-and-cheerful version of `checkTyEqRhs`, called `simpleUnifyCheck`. If `simpleUnifyCheck` succeeds, it can unify, otherwise it defers by emitting a constraint. This is simpler than before. * I simplified the swapping code in `GHC.Tc.Solver.Equality.canEqCanLHS`. Especially the nasty stuff involving `swap_for_occurs` and `canEqTyVarFunEq`. Much nicer now. See Note [Orienting TyVarLHS/TyFamLHS] Note [Orienting TyFamLHS/TyFamLHS] * Added `cteSkolemOccurs`, `cteConcrete`, and `cteCoercionHole` to the problems that can be discovered by `checkTyEqRhs`. * I fixed #23199 `pickQuantifiablePreds`, which actually allows GHC to to accept both cases in #22194 rather than rejecting both. Yet smaller: * Added a `synIsConcrete` flag to `SynonymTyCon` (alongside `synIsFamFree`) to reduce the need for synonym expansion when checking concreteness. Use it in `isConcreteType`. * Renamed `isConcrete` to `isConcreteType` * Defined `GHC.Core.TyCo.FVs.isInjectiveInType` as a more efficient way to find if a particular type variable is used injectively than finding all the injective variables. It is called in `GHC.Tc.Utils.Unify.definitely_poly`, which in turn is used quite a lot. * Moved `rewriterView` to `GHC.Core.Type`, so we can use it from the constraint solver. Fixes #22194, #23199 Compile times decrease by an average of 0.1%; but there is a 7.4% drop in compiler allocation on T15703. Metric Decrease: T15703
* Make WordQuotRem2Op ok-for-speculation tooSylvain Henry2023-04-131-2/+4
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* Add quot folding rule (#22152)Sylvain Henry2023-04-131-15/+82
| | | | | | | (x / l1) / l2 l1 and l2 /= 0 l1*l2 doesn't overflow ==> x / (l1 * l2)
* Add quotRem rules (#22152)Sylvain Henry2023-04-132-0/+65
| | | | | | | | | | | | | | case quotRemInt# x y of (# q, _ #) -> body ====> case quotInt# x y of q -> body case quotRemInt# x y of (# _, r #) -> body ====> case remInt# x y of r -> body
* Clarify a couple of Notes about 'nospec'Simon Peyton Jones2023-04-111-1/+3
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* Fix unification with oversaturated type familiesKrzysztof Gogolewski2023-04-041-29/+115
| | | | | | unify_ty was incorrectly saying that F x y ~ T x are surely apart, where F x y is an oversaturated type family and T x is a tyconapp. As a result, the simplifier dropped a live case alternative (#23134).
* Handle records in the renamersheaf2023-03-296-65/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves the field-based logic for disambiguating record updates to the renamer. The type-directed logic, scheduled for removal, remains in the typechecker. To do this properly (and fix the myriad of bugs surrounding the treatment of duplicate record fields), we took the following main steps: 1. Create GREInfo, a renamer-level equivalent to TyThing which stores information pertinent to the renamer. This allows us to uniformly treat imported and local Names in the renamer, as described in Note [GREInfo]. 2. Remove GreName. Instead of a GlobalRdrElt storing GreNames, which distinguished between normal names and field names, we now store simple Names in GlobalRdrElt, along with the new GREInfo information which allows us to recover the FieldLabel for record fields. 3. Add namespacing for record fields, within the OccNames themselves. This allows us to remove the mangling of duplicate field selectors. This change ensures we don't print mangled names to the user in error messages, and allows us to handle duplicate record fields in Template Haskell. 4. Move record disambiguation to the renamer, and operate on the level of data constructors instead, to handle #21443. The error message text for ambiguous record updates has also been changed to reflect that type-directed disambiguation is on the way out. (3) means that OccEnv is now a bit more complex: we first key on the textual name, which gives an inner map keyed on NameSpace: OccEnv a ~ FastStringEnv (UniqFM NameSpace a) Note that this change, along with (2), both increase the memory residency of GlobalRdrEnv = OccEnv [GlobalRdrElt], which causes a few tests to regress somewhat in compile-time allocation. Even though (3) simplified a lot of code (in particular the treatment of field selectors within Template Haskell and in error messages), it came with one important wrinkle: in the situation of -- M.hs-boot module M where { data A; foo :: A -> Int } -- M.hs module M where { data A = MkA { foo :: Int } } we have that M.hs-boot exports a variable foo, which is supposed to match with the record field foo that M exports. To solve this issue, we add a new impedance-matching binding to M foo{var} = foo{fld} This mimics the logic that existed already for impedance-binding DFunIds, but getting it right was a bit tricky. See Note [Record field impedance matching] in GHC.Tc.Module. We also needed to be careful to avoid introducing space leaks in GHCi. So we dehydrate the GlobalRdrEnv before storing it anywhere, e.g. in ModIface. This means stubbing out all the GREInfo fields, with the function forceGlobalRdrEnv. When we read it back in, we rehydrate with rehydrateGlobalRdrEnv. This robustly avoids any space leaks caused by retaining old type environments. Fixes #13352 #14848 #17381 #17551 #19664 #21443 #21444 #21720 #21898 #21946 #21959 #22125 #22160 #23010 #23062 #23063 Updates haddock submodule ------------------------- Metric Increase: MultiComponentModules MultiLayerModules MultiLayerModulesDefsGhci MultiLayerModulesNoCode T13701 T14697 hard_hole_fits -------------------------
* Make exprIsConApp_maybe a bit clevererwip/T23159Simon Peyton Jones2023-03-271-8/+54
| | | | | | | | | | | | | | | | | | | | | | | Addresses #23159. See Note Note [Exploit occ-info in exprIsConApp_maybe] in GHC.Core.SimpleOpt. Compile times go down very slightly, but always go down, never up. Good! Metrics: compile_time/bytes allocated ------------------------------------------------ CoOpt_Singletons(normal) -1.8% T15703(normal) -1.2% GOOD geo. mean -0.1% minimum -1.8% maximum +0.0% Metric Decrease: CoOpt_Singletons T15703
* Add structured error messages for GHC.Tc.Utils.EnvTorsten Schmits2023-03-211-6/+18
| | | | | | | | | Tracking ticket: #20119 MR: !10129 This converts uses of `mkTcRnUnknownMessage` to newly added constructors of `TcRnMessage`.
* Simplifier: `countValArgs` should not count Type args (#23102)Sebastian Graf2023-03-131-1/+1
| | | | | | | | | I observed miscompilations while working on !10088 caused by this. Fixes #23102. Metric Decrease: T10421
* Simplify: Move `wantEtaExpansion` before expensive `do_eta_expand` checkSebastian Graf2023-03-101-5/+6
| | | | | | | | There is no need to run arity analysis and what not if we are not in a Simplifier phase that eta-expands or if we don't want to eta-expand the expression in the first place. Purely a refactoring with the goal of improving compiler perf.
* DmdAnal: Fix a panic on OPAQUE and trivial/PAP RHS (#22997)Sebastian Graf2023-03-101-10/+12
| | | | | | | We should not panic in `add_demands` (now `set_lam_dmds`), because that code path is legimitely taken for OPAQUE PAP bindings, as in T22997. Fixes #22997.
* Constraint simplification loop now depends on `ExpansionFuel`Apoorv Ingle2023-03-061-2/+5
| | | | | | | | | | | | | | instead of a boolean flag for `CDictCan.cc_pend_sc`. Pending givens get a fuel of 3 while Wanted and quantified constraints get a fuel of 1. This helps pending given constraints to keep up with pending wanted constraints in case of `UndecidableSuperClasses` and superclass expansions while simplifying the infered type. Adds 3 dynamic flags for controlling the fuels for each type of constraints `-fgivens-expansion-fuel` for givens `-fwanteds-expansion-fuel` for wanteds and `-fqcs-expansion-fuel` for quantified constraints Fixes #21909 Added Tests T21909, T21909b Added Note [Expanding Recursive Superclasses and ExpansionFuel]
* More fixes for `type data` declarationsSimon Peyton Jones2023-03-034-10/+36
| | | | | | | | | | | | | | | | | | | | | | This MR fixes #23022 and #23023. Specifically * Beef up Note [Type data declarations] in GHC.Rename.Module, to make invariant (I1) explicit, and to name the several wrinkles. And add references to these specific wrinkles. * Add a Lint check for invariant (I1) above. See GHC.Core.Lint.checkTypeDataConOcc * Disable the `caseRules` for dataToTag# for `type data` values. See Wrinkle (W2c) in the Note above. Fixes #23023. * Refine the assertion in dataConRepArgTys, so that it does not complain about the absence of a wrapper for a `type data` constructor Fixes #23022. Acked-by: Simon Peyton Jones <simon.peytonjones@gmail.com>
* Get the right in-scope set in etaBodyForJoinPointSimon Peyton Jones2023-03-021-4/+11
| | | | Fixes #23026
* constant folding: Correct type of decodeDouble_Int64 ruleMatthew Pickering2023-03-021-5/+1
| | | | | | | | The first argument is Int64# unconditionally, so we better produce something of that type. This fixes a core lint error found in the ad package. Fixes #23019
* Account for TYPE vs CONSTRAINT in mkSelCoSimon Peyton Jones2023-02-283-7/+46
| | | | | | | As #23018 showed, in mkRuntimeRepCo we need to account for coercions between TYPE and COERCION. See Note [mkRuntimeRepCo] in GHC.Core.Coercion.
* Take more care with unlifted bindings in the specialiserSimon Peyton Jones2023-02-281-2/+27
| | | | | | | | As #22998 showed, we were floating an unlifted binding to top level, which breaks a Core invariant. The fix is easy, albeit a little bit conservative. See Note [Care with unlifted bindings] in GHC.Core.Opt.Specialise
* Account for local rules in specImportsSimon Peyton Jones2023-02-282-30/+53
| | | | | | | | | | | As #23024 showed, in GHC.Core.Opt.Specialise.specImports, we were generating specialisations (a locally-define function) for imported functions; and then generating specialisations for those locally-defined functions. The RULE for the latter should be attached to the local Id, not put in the rules-for-imported-ids set. Fix is easy; similar to what happens in GHC.HsToCore.addExportFlagsAndRules
* Don't specialise incoherent instance applicationsGergő Érdi2023-02-271-48/+207
| | | | | | | | | | | | | | Using incoherent instances, there can be situations where two occurrences of the same overloaded function at the same type use two different instances (see #22448). For incoherently resolved instances, we must mark them with `nospec` to avoid the specialiser rewriting one to the other. This marking is done during the desugaring of the `WpEvApp` wrapper. Fixes #22448 Metric Increase: T15304
* Fix shadowing bug in prepareAltsSimon Peyton Jones2023-02-242-13/+26
| | | | | | | | As #23012 showed, GHC.Core.Opt.Simplify.Utils.prepareAlts was using an OutType to construct an InAlt. When shadowing is in play, this is outright wrong. See Note [Shadowing in prepareAlts].
* Don't generate datacon wrappers for `type data` declarationsRyan Scott2023-02-201-3/+35
| | | | | | | | | | | | | | | | | | Data constructor wrappers only make sense for _value_-level data constructors, but data constructors for `type data` declarations only exist at the _type_ level. This patch does the following: * The criteria in `GHC.Types.Id.Make.mkDataConRep` for whether a data constructor receives a wrapper now consider whether or not its parent data type was declared with `type data`, omitting a wrapper if this is the case. * Now that `type data` data constructors no longer receive wrappers, there is a spot of code in `refineDefaultAlt` that panics when it encounters a value headed by a `type data` type constructor. I've fixed this with a special case in `refineDefaultAlt` and expanded `Note [Refine DEFAULT case alternatives]` to explain why we do this. Fixes #22948.
* Expand synonyms in RoughMapsheaf2023-02-161-1/+5
| | | | | | | | | | | We were failing to expand type synonyms in the function GHC.Core.RoughMap.typeToRoughMatchLookupTc, even though the RoughMap infrastructure crucially relies on type synonym expansion to work. This patch adds the missing type-synonym expansion. Fixes #22985
* Narrow the dont-decompose-newtype testSimon Peyton Jones2023-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Following #22924 this patch narrows the test that stops us decomposing newtypes. The key change is the use of noGivenNewtypeReprEqs in GHC.Tc.Solver.Canonical.canTyConApp. We went to and fro on the solution, as you can see in #22924. The result is carefully documented in Note [Decomoposing newtype equalities] On the way I had revert most of commit 3e827c3f74ef76d90d79ab6c4e71aa954a1a6b90 Author: Richard Eisenberg <rae@cs.brynmawr.edu> Date: Mon Dec 5 10:14:02 2022 -0500 Do newtype unwrapping in the canonicaliser and rewriter See Note [Unwrap newtypes first], which has the details. It turns out that (a) 3e827c3f makes GHC behave worse on some recursive newtypes (see one of the tests on this commit) (b) the finer-grained test (namely noGivenNewtypeReprEqs) renders 3e827c3f unnecessary
* Update outdated references to notesSimon Hengel2023-02-141-1/+1
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* Refactor the simplifier a bit to fix #22761Simon Peyton Jones2023-02-107-159/+217
| | | | | | | | | | | | | | | | | | | | | The core change in this commit, which fixes #22761, is that * In a Core rule, ru_rhs is always occ-analysed. This means adding a couple of calls to occurAnalyseExpr when building a Rule, in * GHC.Core.Rules.mkRule * GHC.Core.Opt.Simplify.Iteration.simplRules But diagosing the bug made me stare carefully at the code of the Simplifier, and I ended up doing some only-loosely-related refactoring. * I think that RULES could be lost because not every code path did addBndrRules * The code around lambdas was very convoluted It's mainly moving deck chairs around, but I like it more now.
* Revert "Don't keep exit join points so much"Matthew Pickering2023-02-085-113/+41
| | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit caced75765472a1a94453f2e5a439dba0d04a265. It seems the patch "Don't keep exit join points so much" is causing wide-spread regressions in the bytestring library benchmarks. If I revert it then the 9.6 numbers are better on average than 9.4. See https://gitlab.haskell.org/ghc/ghc/-/issues/22893#note_479525 ------------------------- Metric Decrease: MultiComponentModules MultiComponentModulesRecomp MultiLayerModules MultiLayerModulesRecomp MultiLayerModulesTH_Make T12150 T13386 T13719 T21839c T3294 parsing001 -------------------------
* Update kinds in comments in GHC.Core.TyConromes2023-02-071-20/+20
| | | | | Use `Type` instead of star kind (*) Fix comment with incorrect kind * to have kind `Constraint`
* Minor refactorKrzysztof Gogolewski2023-02-043-12/+10
| | | | | | | | * Introduce refactorDupsOn f = refactorDups (comparing f) * Make mkBigTupleCase and coreCaseTuple monadic. Every call to those functions was preceded by calling newUniqueSupply. * Use mkUserLocalOrCoVar, which is equivalent to combining mkLocalIdOrCoVar with mkInternalName.
* Fix CallerCC potentially shadowing other cost centres.Andreas Klebinger2023-02-032-2/+2
| | | | | | Add a CallerCC cost centre flavour for cost centres added by the CallerCC pass. This avoids potential accidental shadowing between CCs added by user annotations and ones added by CallerCC.
* compiler: Implement higher order patterns in the rule matcherJaro Reinders2023-02-021-8/+176
| | | | | | | | This implements proposal 555 and closes ticket #22465. See the proposal and ticket for motivation. The core changes of this patch are in the GHC.Core.Rules.match function and they are explained in the Note [Matching higher order patterns].
* Treat existentials correctly in dubiousDataConInstArgTysSimon Peyton Jones2023-02-011-8/+17
| | | | | | | | | | | | | Consider (#22849) data T a where MkT :: forall k (t::k->*) (ix::k). t ix -> T @k a Then dubiousDataConInstArgTys MkT [Type, Foo] should return [Foo (ix::Type)] NOT [Foo (ix::k)] A bit of an obscure case, but it's an outright bug, and the fix is easy.
* Improve treatment of type applications in patternswip/T19847Simon Peyton Jones2023-02-011-0/+1
| | | | | | | | | | This patch fixes a subtle bug in the typechecking of type applications in patterns, e.g. f (MkT @Int @a x y) = ... See Note [Type applications in patterns] in GHC.Tc.Gen.Pat. This fixes #19847, #22383, #19577, #21501
* Support "unusable UNPACK pragma" warning with -O0Krzysztof Gogolewski2023-01-311-6/+44
| | | | Fixes #11270
* Improve exprOkForSpeculation for classopsSimon Peyton Jones2023-01-317-37/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes #22745 and #15205, which are about GHC's failure to discard unnecessary superclass selections that yield coercions. See GHC.Core.Utils Note [exprOkForSpeculation and type classes] The main changes are: * Write new Note [NON-BOTTOM_DICTS invariant] in GHC.Core, and refer to it * Define new function isTerminatingType, to identify those guaranteed-terminating dictionary types. * exprOkForSpeculation has a new (very simple) case for ClassOpId * ClassOpId has a new field that says if the return type is an unlifted type, or a terminating type. This was surprisingly tricky to get right. In particular note that unlifted types are not terminating types; you can write an expression of unlifted type, that diverges. Not so for dictionaries (or, more precisely, for the dictionaries that GHC constructs). Metric Decrease: LargeRecord