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* codeGen: Fix signedness of jump table indexingBen Gamari2022-03-182-11/+47
| | | | | | | | | | Previously while constructing the jump table index we would zero-extend the discriminant before subtracting the start of the jump-table. This goes subtly wrong in the case of a sub-word, signed discriminant, as described in the included Note. Fix this in both the PPC and X86 NCGs. Fixes #21186.
* TTG: TH brackets finishing touchesromes2022-03-1810-193/+155
| | | | | | | | | | | | | | | | | | | | | | Rewrite the critical notes and fix outdated ones, use `HsQuote GhcRn` (in `HsBracketTc`) for desugaring regardless of the bracket being typed or untyped, remove unused `EpAnn` from `Hs*Bracket GhcRn`, zonkExpr factor out common brackets code, ppr_expr factor out common brackets code, and fix tests, to finish MR https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4782. ------------------------- Metric Decrease: hard_hole_fits -------------------------
* TTG: Make HsQuote GhcTc isomorphic to NoExtFieldromes2022-03-182-18/+62
| | | | | | | | | | | | | | | | An untyped bracket `HsQuote p` can never be constructed with `p ~ GhcTc`. This is because we don't typecheck `HsQuote` at all. That's OK, because we also never use `HsQuote GhcTc`. To enforce this at the type level we make `HsQuote GhcTc` isomorphic to `NoExtField` and impossible to construct otherwise, by using TTG field extensions to make all constructors, except for `XQuote` (which takes `NoExtField`), unconstructable, with `DataConCantHappen` This is explained more in detail in Note [The life cycle of a TH quotation] Related discussion: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4782
* TTG: Refactor bracket for desugaring during tcromes2022-03-1812-133/+136
| | | | | | | | | | | | | When desugaring a bracket we want to desugar /renamed/ rather than /typechecked/ code; So in (HsExpr GhcTc) tree, we must have a (HsExpr GhcRn) for the quotation itself. This commit reworks the TTG refactor on typed and untyped brackets by storing the /renamed/ code in the bracket field extension rather than in the constructor extension in `HsQuote` (previously called `HsUntypedBracket`) See Note [The life cycle of a TH quotation] and https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4782
* Separate constructors for typed and untyped bracketsromes2022-03-1816-174/+260
| | | | | | | | | | | Split HsBracket into HsTypedBracket and HsUntypedBracket. Unfortunately, we still cannot get rid of instance XXTypedBracket GhcTc = HsTypedBracket GhcRn despite no longer requiring it for typechecking, but rather because the TH desugarer works on GhcRn rather than GhcTc (See GHC.HsToCore.Quote)
* Type-checking untyped bracketsromes2022-03-183-16/+46
| | | | | | | | | | When HsExpr GhcTc, the HsBracket constructor should hold a HsBracket GhcRn, rather than an HsBracket GhcTc. We make use of the HsBracket p extension constructor (XBracket (XXBracket p)) to hold an HsBracket GhcRn when the pass is GhcTc See !4782 https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4782
* TTG: Refactor HsBracketromes2022-03-1812-56/+69
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* Demand: Let `Boxed` win in `lubBoxity` (#21119)Sebastian Graf2022-03-163-117/+227
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, we let `Unboxed` win in `lubBoxity`, which is unsoundly optimistic in terms ob Boxity analysis. "Unsoundly" in the sense that we sometimes unbox parameters that we better shouldn't unbox. Examples are #18907 and T19871.absent. Until now, we thought that this hack pulled its weight becuase it worked around some shortcomings of the phase separation between Boxity analysis and CPR analysis. But it is a gross hack which caused regressions itself that needed all kinds of fixes and workarounds. See for example #20767. It became impossible to work with in !7599, so I want to remove it. For example, at the moment, `lubDmd B dmd` will not unbox `dmd`, but `lubDmd A dmd` will. Given that `B` is supposed to be the bottom element of the lattice, it's hardly justifiable to get a better demand when `lub`bing with `A`. The consequence of letting `Boxed` win in `lubBoxity` is that we *would* regress #2387, #16040 and parts of #5075 and T19871.sumIO, until Boxity and CPR are able to communicate better. Fortunately, that is not the case since I could tweak the other source of optimism in Boxity analysis that is described in `Note [Unboxed demand on function bodies returning small products]` so that we *recursively* assume unboxed demands on function bodies returning small products. See the updated Note. `Note [Boxity for bottoming functions]` describes why we need bottoming functions to have signatures that say that they deeply unbox their arguments. In so doing, I had to tweak `finaliseArgBoxities` so that it will never unbox recursive data constructors. This is in line with our handling of them in CPR. I updated `Note [Which types are unboxed?]` to reflect that. In turn we fix #21119, #20767, #18907, T19871.absent and get a much simpler implementation (at least to think about). We can also drop the very ad-hoc definition of `deferAfterPreciseException` and its Note in favor of the simple, intuitive definition we used to have. Metric Decrease: T16875 T18223 T18698a T18698b hard_hole_fits Metric Increase: LargeRecord MultiComponentModulesRecomp T15703 T8095 T9872d Out of all the regresions, only the one in T9872d doesn't vanish in a perf build, where the compiler is bootstrapped with -O2 and thus SpecConstr. Reason for regressions: * T9872d is due to `ty_co_subst` taking its `LiftingContext` boxed. That is because the context is passed to a function argument, for example in `liftCoSubstTyVarBndrUsing`. * In T15703, LargeRecord and T8095, we get a bit more allocations in `expand_syn` and `piResultTys`, because a `TCvSubst` isn't unboxed. In both cases that guards against reboxing in some code paths. * The same is true for MultiComponentModulesRecomp, where we get less unboxing in `GHC.Unit.Finder.$wfindInstalledHomeModule`. In a perf build, allocations actually *improve* by over 4%! Results on NoFib: -------------------------------------------------------------------------------- Program Allocs Instrs -------------------------------------------------------------------------------- awards -0.4% +0.3% cacheprof -0.3% +2.4% fft -1.5% -5.1% fibheaps +1.2% +0.8% fluid -0.3% -0.1% ida +0.4% +0.9% k-nucleotide +0.4% -0.1% last-piece +10.5% +13.9% lift -4.4% +3.5% mandel2 -99.7% -99.8% mate -0.4% +3.6% parser -1.0% +0.1% puzzle -11.6% +6.5% reverse-complem -3.0% +2.0% scs -0.5% +0.1% sphere -0.4% -0.2% wave4main -8.2% -0.3% -------------------------------------------------------------------------------- Summary excludes mandel2 because of excessive bias Min -11.6% -5.1% Max +10.5% +13.9% Geometric Mean -0.2% +0.3% -------------------------------------------------------------------------------- Not bad for a bug fix. The regression in `last-piece` could become a win if SpecConstr would work on non-recursive functions. The regression in `fibheaps` is due to `Note [Reboxed crud for bottoming calls]`, e.g., #21128.
* TH: allow negative patterns in quotes (#20711)Zubin Duggal2022-03-161-1/+8
| | | | | | We still don't allow negative overloaded patterns. Earler all negative patterns were treated as negative overloaded patterns. Now, we expliclty check the extension field to see if the pattern is actually a negative overloaded pattern
* Suggest FFI extensions as hints (#20116)Aaron Allen2022-03-162-5/+5
| | | | | | - Use extension suggestion hints instead of suggesting extensions in the error message body for several FFI errors. - Adds a test case for `TcRnForeignImportPrimExtNotSet`
* Convert Diagnostics in GHC.Tc.Gen.ForeignAaron Allen2022-03-167-149/+385
| | | | Converts all uses of 'TcRnUnknownMessage' to proper diagnostics.
* Export (~) from Data.Type.Equality (#18862)wip/eqtycon-rnVladislav Zavialov2022-03-1512-59/+110
| | | | | | | | | | * Users can define their own (~) type operator * Haddock can display documentation for the built-in (~) * New transitional warnings implemented: -Wtype-equality-out-of-scope -Wtype-equality-requires-operators Updates the haddock submodule.
* DmdAnal: Don't unbox recursive data types (#11545)Sebastian Graf2022-03-145-42/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As `Note [Demand analysis for recursive data constructors]` describes, we now refrain from unboxing recursive data type arguments, for two reasons: 1. Relating to run/alloc perf: Similar to `Note [CPR for recursive data constructors]`, it seldomly improves run/alloc performance if we just unbox a finite number of layers of a potentially huge data structure. 2. Relating to ghc/alloc perf: Inductive definitions on single-product recursive data types like the one in T11545 will (diverge, and) have very deep demand signatures before any other abortion mechanism in Demand analysis is triggered. That leads to great and unnecessary churn on Demand analysis when ultimately we will never make use of any nested strictness information anyway. Conclusion: Discard nested demand and boxity information on such recursive types with the help of `Note [Detecting recursive data constructors]`. I also implemented `GHC.Types.Unique.MemoFun.memoiseUniqueFun` in order to avoid the overhead of repeated calls to `GHC.Core.Opt.WorkWrap.Utils.isRecDataCon`. It's nice and simple and guards against some smaller regressions in T9233 and T16577. ghc/alloc performance-wise, this patch is a very clear win: Test Metric value New value Change --------------------------------------------------------------------------------------- LargeRecord(normal) ghc/alloc 6,141,071,720 6,099,871,216 -0.7% MultiLayerModulesTH_OneShot(normal) ghc/alloc 2,740,973,040 2,705,146,640 -1.3% T11545(normal) ghc/alloc 945,475,492 85,768,928 -90.9% GOOD T13056(optasm) ghc/alloc 370,245,880 326,980,632 -11.7% GOOD T18304(normal) ghc/alloc 90,933,944 76,998,064 -15.3% GOOD T9872a(normal) ghc/alloc 1,800,576,840 1,792,348,760 -0.5% T9872b(normal) ghc/alloc 2,086,492,432 2,073,991,848 -0.6% T9872c(normal) ghc/alloc 1,750,491,240 1,737,797,832 -0.7% TcPlugin_RewritePerf(normal) ghc/alloc 2,286,813,400 2,270,957,896 -0.7% geo. mean -2.9% No noteworthy change in run/alloc either. NoFib results show slight wins, too: -------------------------------------------------------------------------------- Program Allocs Instrs -------------------------------------------------------------------------------- constraints -1.9% -1.4% fasta -3.6% -2.7% reverse-complem -0.3% -0.9% treejoin -0.0% -0.3% -------------------------------------------------------------------------------- Min -3.6% -2.7% Max +0.1% +0.1% Geometric Mean -0.1% -0.1% Metric Decrease: T11545 T13056 T18304
* Fix isLiftedType_maybe and handle falloutsheaf2022-03-1446-374/+703
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As #20837 pointed out, `isLiftedType_maybe` returned `Just False` in many situations where it should return `Nothing`, because it didn't take into account type families or type variables. In this patch, we fix this issue. We rename `isLiftedType_maybe` to `typeLevity_maybe`, which now returns a `Levity` instead of a boolean. We now return `Nothing` for types with kinds of the form `TYPE (F a1 ... an)` for a type family `F`, as well as `TYPE (BoxedRep l)` where `l` is a type variable. This fix caused several other problems, as other parts of the compiler were relying on `isLiftedType_maybe` returning a `Just` value, and were now panicking after the above fix. There were two main situations in which panics occurred: 1. Issues involving the let/app invariant. To uphold that invariant, we need to know whether something is lifted or not. If we get an answer of `Nothing` from `isLiftedType_maybe`, then we don't know what to do. As this invariant isn't particularly invariant, we can change the affected functions to not panic, e.g. by behaving the same in the `Just False` case and in the `Nothing` case (meaning: no observable change in behaviour compared to before). 2. Typechecking of data (/newtype) constructor patterns. Some programs involving patterns with unknown representations were accepted, such as T20363. Now that we are stricter, this caused further issues, culminating in Core Lint errors. However, the behaviour was incorrect the whole time; the incorrectness only being revealed by this change, not triggered by it. This patch fixes this by overhauling where the representation polymorphism involving pattern matching are done. Instead of doing it in `tcMatches`, we instead ensure that the `matchExpected` functions such as `matchExpectedFunTys`, `matchActualFunTySigma`, `matchActualFunTysRho` allow return argument pattern types which have a fixed RuntimeRep (as defined in Note [Fixed RuntimeRep]). This ensures that the pattern matching code only ever handles types with a known runtime representation. One exception was that patterns with an unknown representation type could sneak in via `tcConPat`, which points to a missing representation-polymorphism check, which this patch now adds. This means that we now reject the program in #20363, at least until we implement PHASE 2 of FixedRuntimeRep (allowing type families in RuntimeRep positions). The aforementioned refactoring, in which checks have been moved to `matchExpected` functions, is a first step in implementing PHASE 2 for patterns. Fixes #20837
* TTG Pull AbsBinds and ABExport out of the main ASTromes2022-03-1416-144/+238
| | | | | | | | | | | | | | AbsBinds and ABExport both depended on the typechecker, and were thus removed from the main AST Expr. CollectPass now has a new function `collectXXHsBindsLR` used for the new HsBinds extension point Bumped haddock submodule to work with AST changes. The removed Notes from Language.Haskell.Syntax.Binds were duplicated (and not referenced) and the copies in GHC.Hs.Binds are kept (and referenced there). (See #19252)
* Fix up Note [Bind free vars]romes2022-03-141-8/+25
| | | | | | | | | | | | Move GHC-specific comments from Language.Haskell.Syntax.Binds to GHC.Hs.Binds It looks like the Note was deleted but there were actually two copies of it. L.H.S.B no longer references it, and GHC.Hs.Binds keeps an updated copy. (See #19252) There are other duplicated notes -- they will be fixed in the next commit
* Worker/wrapper: Preserve float barriers (#21150)Sebastian Graf2022-03-137-87/+133
| | | | | | | | | | | | | | | | | | | | | | | Issue #21150 shows that worker/wrapper allocated a worker function for a function with multiple calls that said "called at most once" when the first argument was absent. That's bad! This patch makes it so that WW preserves at least one non-one-shot value lambda (see `Note [Preserving float barriers]`) by passing around `void#` in place of absent arguments. Fixes #21150. Since the fix is pretty similar to `Note [Protecting the last value argument]`, I put the logic in `mkWorkerArgs`. There I realised (#21204) that `-ffun-to-thunk` is basically useless with `-ffull-laziness`, so I deprecated the flag, simplified and split into `needsVoidWorkerArg`/`addVoidWorkerArg`. SpecConstr is another client of that API. Fixes #21204. Metric Decrease: T14683
* Fix bug in weak loop-breakers in OccurAnalSimon Peyton Jones2022-03-131-10/+24
| | | | | | | | | | | Note [Weak loop breakers] explains why we need to track variables free in RHS of rules. But we need to do this for /inactive/ rules as well as active ones, unlike the rhs_fv_env stuff. So we now have two fields in node Details, one for free vars of active rules, and one for free vars of all rules. This was shown up by #20820, which is now fixed.
* Rename -fprof-late-ccs to -fprof-lateAndreas Klebinger2022-03-121-1/+1
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* checkUnboxedLitPat: use non-fatal addErrorVladislav Zavialov2022-03-121-2/+2
| | | | This enables GHC to report more parse errors in a single pass.
* CmmToC: make floatToWord32/doubleToWord64 fasterCheng Shao2022-03-111-24/+3
| | | | | Use castFloatToWord32/castDoubleToWord64 in base to perform the reinterpret cast.
* CmmToC: emit __builtin_unreachable() when CmmSwitch doesn't contain fallback ↵Cheng Shao2022-03-111-1/+1
| | | | | | | case Otherwise the C compiler may complain "warning: non-void function does not return a value in all control paths [-Wreturn-type]".
* CmmToC: use __builtin versions of memcpyish functions to fix type mismatchCheng Shao2022-03-111-5/+4
| | | | | | | | | | | | | Our memcpyish primop's type signatures doesn't match the C type signatures. It's not a problem for typical archs, since their C ABI permits dropping the result, but it doesn't work for wasm. The previous logic would cast the memcpyish function pointer to an incorrect type and perform an indirect call, which results in a runtime trap on wasm. The most straightforward fix is: don't emit EFF_ for memcpyish functions. Since we don't want to include extra headers in .hc to bring in their prototypes, we can just use the __builtin versions.
* CmmToC: fix Double# literal payload for 32-bit targetsCheng Shao2022-03-111-3/+2
| | | | | | Contrary to the legacy comment, the splitting didn't happen and we ended up with a single StgWord64 literal in the output code! Let's just do the splitting here.
* CmmToC: make 64-bit word splitting for 32-bit targets respect target endiannessCheng Shao2022-03-111-1/+3
| | | | This used to been broken for little-endian targets.
* Demand: Document why we need three additional equations of multSubDmdSebastian Graf2022-03-111-17/+20
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* Improve -dtag-inference-checks checks.Andreas Klebinger2022-03-113-13/+40
| | | | | FUN closures don't get tagged when evaluated. So no point in checking their tags.
* Remove partOfGhci check in the loaderMatthew Pickering2022-03-111-29/+7
| | | | | | | | | | | | | | | | | | This special logic has been part of GHC ever since template haskell was introduced in 9af77fa423926fbda946b31e174173d0ec5ebac8. It's hard to believe in any case that this special logic pays its way at all. Given * The list is out-of-date, which has potential to lead to miscompilation when using "editline", which was removed in 2010 (46aed8a4). * The performance benefit seems negligable as each load only happens once anyway and packages specified by package flags are preloaded into the linker state at the start of compilation. Therefore we just remove this logic. Fixes #19791
* gitlab-ci: Use the linters image in hlint jobBen Gamari2022-03-119-10/+1
| | | | | | As the `hlint` executable is only available in the linters image. Fixes #21146.
* Refactor tcDeriving to generate tyfam insts before any bindingsRyan Scott2022-03-116-309/+347
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, there was an awful hack in `genInst` (now called `genInstBinds` after this patch) where we had to return a continutation rather than directly returning the bindings for a derived instance. This was done for staging purposes, as we had to first infer the instance contexts for derived instances and then feed these contexts into the continuations to ensure the generated instance bindings had accurate instance contexts. `Note [Staging of tcDeriving]` in `GHC.Tc.Deriving` described this confusing state of affairs. The root cause of this confusing design was the fact that `genInst` was trying to generate instance bindings and associated type family instances for derived instances simultaneously. This really isn't possible, however: as `Note [Staging of tcDeriving]` explains, one needs to have access to the associated type family instances before one can properly infer the instance contexts for derived instances. The use of continuation-returning style was an attempt to circumvent this dependency, but it did so in an awkward way. This patch detangles this awkwardness by splitting up `genInst` into two functions: `genFamInsts` (for associated type family instances) and `genInstBinds` (for instance bindings). Now, the `tcDeriving` function calls `genFamInsts` and brings all the family instances into scope before calling `genInstBinds`. This removes the need for the awkward continuation-returning style seen in the previous version of `genInst`, making the code easier to understand. There are some knock-on changes as well: 1. `hasStockDeriving` now needs to return two separate functions: one that describes how to generate family instances for a stock-derived instance, and another that describes how to generate the instance bindings. I factored out this pattern into a new `StockGenFns` data type. 2. While documenting `StockGenFns`, I realized that there was some inconsistency regarding which `StockGenFns` functions needed which arguments. In particular, the function in `GHC.Tc.Deriv.Generics` which generates `Rep(1)` instances did not take a `SrcSpan` like other `gen_*` functions did, and it included an extra `[Type]` argument that was entirely redundant. As a consequence, I refactored the code in `GHC.Tc.Deriv.Generics` to more closely resemble other `gen_*` functions. A happy result of all this is that all `StockGenFns` functions now take exactly the same arguments, which makes everything more uniform. This is purely a refactoring that should not have any effect on user-observable behavior. The new design paves the way for an eventual fix for #20719.
* Add an inline pragma to lookupVarEnvMatthew Pickering2022-03-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | The containers bump reduced the size of the Data.IntMap.Internal.lookup function so that it no longer experienced W/W. This means that the size of lookupVarEnv increased over the inlining threshold and it wasn't inlined into the hot code path in substTyVar. See containers#821, #21159 and !7638 for some more explanation. ------------------------- Metric Decrease: LargeRecord T12227 T13386 T15703 T18223 T5030 T8095 T9872a T9872b T9872c TcPlugin_RewritePerf -------------------------
* Delete GenericKind_ in favor of GenericKind_DCRyan Scott2022-03-071-71/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When deriving a `Generic1` instance, we need to know what the last type variable of a data type is. Previously, there were two mechanisms to determine this information: * `GenericKind_`, where `Gen1_` stored the last type variable of a data type constructor (i.e., the `tyConTyVars`). * `GenericKind_DC`, where `Gen1_DC` stored the last universally quantified type variable in a data constructor (i.e., the `dataConUnivTyVars`). These had different use cases, as `GenericKind_` was used for generating `Rep(1)` instances, while `GenericKind_DC` was used for generating `from(1)` and `to(1)` implementations. This was already a bit confusing, but things went from confusing to outright wrong after !6976. This is because after !6976, the `deriving` machinery stopped using `tyConTyVars` in favor of `dataConUnivTyVars`. Well, everywhere with the sole exception of `GenericKind_`, which still continued to use `tyConTyVars`. This lead to disaster when deriving a `Generic1` instance for a GADT family instance, as the `tyConTyVars` do not match the `dataConUnivTyVars`. (See #21185.) The fix is to stop using `GenericKind_` and replace it with `GenericKind_DC`. For the most part, this proves relatively straightforward. Some highlights: * The `forgetArgVar` function was deleted entirely, as it no longer proved necessary after `GenericKind_`'s demise. * The substitution that maps from the last type variable to `Any` (see `Note [Generating a correctly typed Rep instance]`) had to be moved from `tc_mkRepTy` to `tc_mkRepFamInsts`, as `tc_mkRepTy` no longer has access to the last type variable. Fixes #21185.
* Expand and improve the Note [Strict Worker Ids].Andreas Klebinger2022-03-072-5/+24
| | | | | I've added an explicit mention of the invariants surrounding those. As well as adding more direct cross references to the Strict Field Invariant.
* Fix reporting constraints in pprTcSolverReportMsgKrzysztof Gogolewski2022-03-071-17/+23
| | | | 'no_instance_msg' and 'no_deduce_msg' were omitting the first wanted.
* Always generalise top-level bindingsSimon Peyton Jones2022-03-071-13/+33
| | | | | Fix #21023 by always generalising top-level binding; change the documentation of -XMonoLocalBinds to match.
* Don't allow Float#/Double# literal patternssheaf2022-03-057-16/+51
| | | | | | | | | | | | | | This patch does the following two things: 1. Fix the check in Core Lint to properly throw an error when it comes across Float#/Double# literal patterns. The check was incorrect before, because it expected the type to be Float/Double instead of Float#/Double#. 2. Add an error in the parser when the user writes a floating-point literal pattern such as `case x of { 2.0## -> ... }`. Fixes #21115
* Fix comments about Int64/Word64 primopsSylvain Henry2022-03-041-6/+2
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* Replace ad-hoc CPP with constant from GHC.Utils.ConstantMatthew Pickering2022-03-031-8/+2
| | | | Fixes #21154
* GenStgAlt 3-tuple synonym --> Record typedoyougnu2022-03-0218-112/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit alters GenStgAlt from a type synonym to a Record with field accessors. In pursuit of #21078, this is not a required change but cleans up several areas for nicer code in the upcoming js-backend, and in GHC itself. GenStgAlt: 3-tuple -> record Stg.Utils: GenStgAlt 3-tuple -> record Stg.Stats: StgAlt 3-tuple --> record Stg.InferTags.Rewrite: StgAlt 3-tuple -> record Stg.FVs: GenStgAlt 3-tuple -> record Stg.CSE: GenStgAlt 3-tuple -> record Stg.InferTags: GenStgAlt 3-tuple --> record Stg.Debug: GenStgAlt 3-tuple --> record Stg.Lift.Analysis: GenStgAlt 3-tuple --> record Stg.Lift: GenStgAlt 3-tuple --> record ByteCode.Instr: GenStgAlt 3-tuple --> record Stg.Syntax: add GenStgAlt helper functions Stg.Unarise: GenStgAlt 3-tuple --> record Stg.BcPrep: GenStgAlt 3-tuple --> record CoreToStg: GenStgAlt 3-tuple --> record StgToCmm.Expr: GenStgAlt 3-tuple --> record StgToCmm.Bind: GenStgAlt 3-tuple --> record StgToByteCode: GenStgAlt 3-tuple --> record Stg.Lint: GenStgAlt 3-tuple --> record Stg.Syntax: strictify GenStgAlt GenStgAlt: add haddock, some cleanup fixup: remove calls to pure, single ViewPattern StgToByteCode: use case over viewpatterns
* Make Constraint not *apart* from Type.Richard Eisenberg2022-03-022-28/+33
| | | | | | More details in Note [coreView vs tcView] Close #21092.
* Make inert_cycle_breakers into a stack.Richard Eisenberg2022-03-023-19/+79
| | | | Close #20231.
* Improve out-of-order inferred type variablessheaf2022-03-024-30/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't instantiate type variables for :type in `GHC.Tc.Gen.App.tcInstFun`, to avoid inconsistently instantianting `r1` but not `r2` in the type forall {r1} (a :: TYPE r1) {r2} (b :: TYPE r2). ... This fixes #21088. This patch also changes the primop pretty-printer to ensure that we put all the inferred type variables first. For example, the type of reallyUnsafePtrEquality# is now forall {l :: Levity} {k :: Levity} (a :: TYPE (BoxedRep l)) (b :: TYPE (BoxedRep k)). a -> b -> Int# This means we avoid running into issue #21088 entirely with the types of primops. Users can still write a type signature where the inferred type variables don't come first, however. This change to primops had a knock-on consequence, revealing that we were sometimes performing eta reduction on keepAlive#. This patch updates tryEtaReduce to avoid eta reducing functions with no binding, bringing it in line with tryEtaReducePrep, and thus fixing #21090.
* Make -dannot-lint not panic on let bound type variablesMatthew Pickering2022-03-021-1/+8
| | | | | | | | | After certain simplifier passes we end up with let bound type variables which are immediately inlined in the next pass. The core diff utility implemented by -dannot-lint failed to take these into account and paniced. Progress towards #20965
* Introduce ConcreteTv metavariablessheaf2022-03-0229-790/+696
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a new kind of metavariable, by adding the constructor `ConcreteTv` to `MetaInfo`. A metavariable with `ConcreteTv` `MetaInfo`, henceforth a concrete metavariable, can only be unified with a type that is concrete (that is, a type that answers `True` to `GHC.Core.Type.isConcrete`). This solves the problem of dangling metavariables in `Concrete#` constraints: instead of emitting `Concrete# ty`, which contains a secret existential metavariable, we simply emit a primitive equality constraint `ty ~# concrete_tv` where `concrete_tv` is a fresh concrete metavariable. This means we can avoid all the complexity of canonicalising `Concrete#` constraints, as we can just re-use the existing machinery for `~#`. To finish things up, this patch then removes the `Concrete#` special predicate, and instead introduces the special predicate `IsRefl#` which enforces that a coercion is reflexive. Such a constraint is needed because the canonicaliser is quite happy to rewrite an equality constraint such as `ty ~# concrete_tv`, but such a rewriting is not handled by the rest of the compiler currently, as we need to make use of the resulting coercion, as outlined in the FixedRuntimeRep plan. The big upside of this approach (on top of simplifying the code) is that we can now selectively implement PHASE 2 of FixedRuntimeRep, by changing individual calls of `hasFixedRuntimeRep_MustBeRefl` to `hasFixedRuntimeRep` and making use of the obtained coercion.
* StgToCmm.cgTopBinding: no isNCG, use binBlobThreshdoyougnu2022-03-024-16/+22
| | | | | | | | | | | | | | | | | | | | | | | | | This is a one line change. It is a fixup from MR!7325, was pointed out in review of MR!7442, specifically: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/7442#note_406581 The change removes isNCG check from cgTopBinding. Instead it changes the type of binBlobThresh in DynFlags from Word to Maybe Word, where a Just 0 or a Nothing indicates an infinite threshold and thus the disable CmmFileEmbed case in the original check. This improves the cohesion of the module because more NCG related Backend stuff is moved into, and checked in, StgToCmm.Config. Note, that the meaning of a Just 0 or a Nothing in binBlobThresh is indicated in a comment next to its field in GHC.StgToCmm.Config. DynFlags: binBlobThresh: Word -> Maybe Word StgToCmm.Config: binBlobThesh add not ncg check DynFlags.binBlob: move Just 0 check to dflags init StgToCmm.binBlob: only check isNCG, Just 0 check to dflags StgToCmm.Config: strictify binBlobThresh
* Ticky profiling improvements.Matthew Pickering2022-03-0213-47/+168
| | | | | | | | | | | | | | | | | | | | This adds a number of changes to ticky-ticky profiling. When an executable is profiled with IPE profiling it's now possible to associate id-related ticky counters to their source location. This works by emitting the info table address as part of the counter which can be looked up in the IPE table. Add a `-ticky-ap-thunk` flag. This flag prevents the use of some standard thunks which are precompiled into the RTS. This means reduced cache locality and increased code size. But it allows better attribution of execution cost to specific source locations instead of simple attributing it to the standard thunk. ticky-ticky now uses the `arg` field to emit additional information about counters in json format. When ticky-ticky is used in combination with the eventlog eventlog2html can be used to generate a html table from the eventlog similar to the old text output for ticky-ticky.
* Core Lint: collect args through floatable tickssheaf2022-03-011-1/+11
| | | | | | | | | | | | | | | | | | We were not looking through floatable ticks when collecting arguments in Core Lint, which caused `checkCanEtaExpand` to fail on something like: ```haskell reallyUnsafePtrEquality = \ @a -> (src<loc> reallyUnsafePtrEquality#) @Lifted @a @Lifted @a ``` We fix this by using `collectArgsTicks tickishFloatable` instead of `collectArgs`, to be consistent with the behaviour of eta expansion outlined in Note [Eta expansion and source notes] in GHC.Core.Opt.Arity. Fixes #21152.
* driver: Properly add an edge between a .hs and its hs-boot fileMatthew Pickering2022-03-014-45/+37
| | | | | | | | | | | | | | As noted in #21071 we were missing adding this edge so there were situations where the .hs file would get compiled before the .hs-boot file which leads to issues with -j. I fixed this properly by adding the edge in downsweep so the definition of nodeDependencies can be simplified to avoid adding this dummy edge in. There are plenty of tests which seem to have these redundant boot files anyway so no new test. #21094 tracks the more general issue of identifying redundant hs-boot and SOURCE imports.
* Fix longstanding issue with moduleGraphNodes - no hs-boot files caseMatthew Pickering2022-03-011-12/+28
| | | | | | | | | | | | | | | | | | | | In the case when we tell moduleGraphNodes to drop hs-boot files the idea is to collapse hs-boot files into their hs file nodes. In the old code * nodeDependencies changed edges from IsBoot to NonBoot * moduleGraphNodes just dropped boot file nodes The net result is that any dependencies of the hs-boot files themselves were dropped. The correct thing to do is * nodeDependencies changes edges from IsBoot to NonBoot * moduleGraphNodes merges dependencies of IsBoot and NonBoot nodes. The result is a properly quotiented dependency graph which contains no hs-boot files nor hs-boot file edges. Why this didn't cause endless issues when compiling with boot files, we will never know.
* linking: Don't pass --hash-size and --reduce-memory-overhead to ldMatthew Pickering2022-02-281-14/+4
| | | | | | | | | | | | | | | | | | These flags were added to help with the high linking cost of the old split-objs mode. Now we are using split-sections these flags appear to make no difference to memory usage or time taken to link. I tested various configurations linking together the ghc library with -split-sections enabled. | linker | time (s) | | ------ | ------ | | gold | 0.95 | | ld | 1.6 | | ld (hash-size = 31, reduce-memory-overheads) | 1.6 | | ldd | 0.47 | Fixes #20967
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