summaryrefslogtreecommitdiff
path: root/compiler/GHC/Core
Commit message (Collapse)AuthorAgeFilesLines
* PmCheck: Handle ⊥ and strict fields correctly (#18341)wip/T18341Sebastian Graf2020-09-101-1/+5
| | | | | | | | | | | | | | | | | | | | | In #18341, we discovered an incorrect digression from Lower Your Guards. This MR changes what's necessary to support properly fixing #18341. In particular, bottomness constraints are now properly tracked in the oracle/inhabitation testing, as an additional field `vi_bot :: Maybe Bool` in `VarInfo`. That in turn allows us to model newtypes as advertised in the Appendix of LYG and fix #17725. Proper handling of ⊥ also fixes #17977 (once again) and fixes #18670. For some reason I couldn't follow, this also fixes #18273. I also added a couple of regression tests that were missing. Most of them were already fixed before. In summary, this patch fixes #18341, #17725, #18273, #17977 and #18670. Metric Decrease: T12227
* Add comments about sm_dflags and simpleOptExprSylvain Henry2020-09-092-2/+19
|
* DynFlags: add sm_pre_inline field into SimplMode (#17957)Sylvain Henry2020-09-099-39/+41
| | | | It avoids passing and querying DynFlags down in the simplifier.
* DynFlags: add UnfoldingOpts and SimpleOptsSylvain Henry2020-09-0916-409/+553
| | | | | Milestone: after this patch, we only use 'unsafeGlobalDynFlags' for the state hack and for debug in Outputable.
* DynFlags: add OptCoercionOptsSylvain Henry2020-09-094-21/+47
| | | | | Use OptCoercionOpts to avoid threading DynFlags all the way down to GHC.Core.Coercion.Opt
* Postpone associated tyfam default checks until after typecheckingRyan Scott2020-09-091-2/+13
| | | | | | | | | | | | Previously, associated type family defaults were validity-checked during typechecking. Unfortunately, the error messages that these checks produce run the risk of printing knot-tied type constructors, which will cause GHC to diverge. In order to preserve the current error message's descriptiveness, this patch postpones these validity checks until after typechecking, which are now located in the new function `GHC.Tc.Validity.checkValidAssocTyFamDeflt`. Fixes #18648.
* Use "to" instead of "2" in internal names of conversion opsJohn Ericson2020-09-091-15/+15
| | | | | | | | | | | Change the constructors for the primop union, and also names of the literal conversion functions. "2" runs into trouble when we need to do conversions from fixed-width types, and end up with thing like "Int642Word". Only the names internal to GHC are changed, as I don't want to worry about breaking changes ATM.
* Introduce isBoxedTupleDataCon and use it to fix #18644Ryan Scott2020-09-046-13/+17
| | | | | | | | | | | | | | | | | | | | The code that converts promoted tuple data constructors to `IfaceType`s in `GHC.CoreToIface` was using `isTupleDataCon`, which conflates boxed and unboxed tuple data constructors. To avoid this, this patch introduces `isBoxedTupleDataCon`, which is like `isTupleDataCon` but only works for _boxed_ tuple data constructors. While I was in town, I was horribly confused by the fact that there were separate functions named `isUnboxedTupleCon` and `isUnboxedTupleTyCon` (similarly, `isUnboxedSumCon` and `isUnboxedSumTyCon`). It turns out that the former only works for data constructors, despite its very general name! I opted to rename `isUnboxedTupleCon` to `isUnboxedTupleDataCon` (similarly, I renamed `isUnboxedSumCon` to `isUnboxedSumDataCon`) to avoid this potential confusion, as well as to be more consistent with the naming convention I used for `isBoxedTupleDataCon`. Fixes #18644.
* Turn on -XMonoLocalBinds by default (#18430)Sebastian Graf2020-09-022-1/+2
| | | | | | | | | And fix the resulting type errors. Co-authored-by: Krzysztof Gogolewski <krz.gogolewski@gmail.com> Metric Decrease: parsing001
* Remove "Ord FastString" instanceSylvain Henry2020-09-015-13/+22
| | | | | | | | | | | | | | | | | | | FastStrings can be compared in 2 ways: by Unique or lexically. We don't want to bless one particular way with an "Ord" instance because it leads to bugs (#18562) or to suboptimal code (e.g. using lexical comparison while a Unique comparison would suffice). UTF-8 encoding has the advantage that sorting strings by their encoded bytes also sorts them by their Unicode code points, without having to decode the actual code points. BUT GHC uses Modified UTF-8 which diverges from UTF-8 by encoding \0 as 0xC080 instead of 0x00 (to avoid null bytes in the middle of a String so that the string can still be null-terminated). This patch adds a new `utf8CompareShortByteString` function that performs sorting by bytes but that also takes Modified UTF-8 into account. It is much more performant than decoding the strings into [Char] to perform comparisons (which we did in the previous patch). Bump haddock submodule
* Use tcView, not coreView, in the pure unifier.Richard Eisenberg2020-08-252-3/+24
| | | | Addresses a lingering point within #11715.
* Fix types in silly shifts (#18589)Krzysztof Gogolewski2020-08-241-9/+13
| | | | Patch written by Simon. I have only added a testcase.
* mkUnique refactoring (#18362)Aditya Gupta2020-08-227-6/+22
| | | | | Move uniqFromMask from Unique.Supply to Unique. Move the the functions that call mkUnique from Unique to Builtin.Uniques
* Allow unsaturated runRW# applicationsBen Gamari2020-08-182-36/+18
| | | | | | | | | | | | | | | | | | Previously we had a very aggressive Core Lint check which caught unsaturated applications of runRW#. However, there is nothing wrong with such applications and they may naturally arise in desugared Core. For instance, the desugared Core of Data.Primitive.Array.runArray# from the `primitive` package contains: case ($) (runRW# @_ @_) (\s -> ...) of ... In this case it's almost certain that ($) will be inlined, turning the application into a saturated application. However, even if this weren't the case there isn't a problem: CorePrep (after deleting an unnecessary case) can simply generate code in its usual way, resulting in a call to the Haskell definition of runRW#. Fixes #18291.
* Add HomeUnit typeSylvain Henry2020-08-131-2/+5
| | | | | | | | | | | | | | | | | | | | | | | Since Backpack the "home unit" is much more involved than what it was before (just an identifier obtained with `-this-unit-id`). Now it is used in conjunction with `-component-id` and `-instantiated-with` to configure module instantiations and to detect if we are type-checking an indefinite unit or compiling a definite one. This patch introduces a new HomeUnit datatype which is much easier to understand. Moreover to make GHC support several packages in the same instances, we will need to handle several HomeUnits so having a dedicated (documented) type is helpful. Finally in #14335 we will also need to handle the case where we have no HomeUnit at all because we are only loading existing interfaces for plugins which live in a different space compared to units used to produce target code. Several functions will have to be refactored to accept "Maybe HomeUnit" parameters instead of implicitly querying the HomeUnit fields in DynFlags. Having a dedicated type will make this easier. Bump haddock submodule
* PmCheck: Better long-distance info for where bindings (#18533)Sebastian Graf2020-08-131-0/+3
| | | | | | | | | | | | | | | | | | | | Where bindings can see evidence from the pattern match of the `GRHSs` they belong to, but not from anything in any of the guards (which belong to one of possibly many RHSs). Before this patch, we did *not* consider said evidence, causing #18533, where the lack of considering type information from a case pattern match leads to failure to resolve the vanilla COMPLETE set of a data type. Making available that information required a medium amount of refactoring so that `checkMatches` can return a `[(Deltas, NonEmpty Deltas)]`; one `(Deltas, NonEmpty Deltas)` for each `GRHSs` of the match group. The first component of the pair is the covered set of the pattern, the second component is one covered set per RHS. Fixes #18533. Regression test case: T18533
* Rewrite and move the monad-state hack noteSylvain Henry2020-08-123-75/+4
| | | | | | The note has been rewritten by @simonpj in !3851 [skip ci]
* DynFlags: disentangle OutputableSylvain Henry2020-08-1243-19/+92
| | | | | | | | | - put panic related functions into GHC.Utils.Panic - put trace related functions using DynFlags in GHC.Driver.Ppr One step closer making Outputable fully independent of DynFlags. Bump haddock submodule
* Fix debug_ppr_ty ForAllTy (#18522)Vladislav Zavialov2020-08-061-12/+28
| | | | | | | Before this change, GHC would pretty-print forall k. forall a -> () as forall @k a. () which isn't even valid Haskell.
* Rename Core.Opt.Driver -> Core.Opt.PipelineKrzysztof Gogolewski2020-08-052-2/+2
| | | | Closes #18504.
* DynFlags: don't use sdocWithDynFlags in datacon pprSylvain Henry2020-07-302-8/+6
| | | | | | | We don't need to use `sdocWithDynFlags` to know whether we should display linear types for datacon types, we already have `sdocLinearTypes` field in `SDocContext`. Moreover we want to remove `sdocWithDynFlags` (#10143, #17957)).
* Add two bangs to improve perf of flatteningSimon Peyton Jones2020-07-301-4/+6
| | | | | | | | | | | | | | | | | | | | This tiny patch improves the compile time of flatten-heavy programs by 1-2%, by adding two bangs. Addresses (somewhat) #18502 This reduces allocation by T9872b -1.1% T9872d -3.3% T5321Fun -0.2% T5631 -0.2% T5837 +0.1% T6048 +0.1% Metric Decrease: T9872b T9872d
* Kill off sc_mult and as_mult fieldsSimon Peyton Jones2020-07-292-67/+42
| | | | | | | They are readily derivable from other fields, so this is more efficient, and less error prone. Fixes #18494
* This patch addresses the exponential blow-up in the simplifier.Simon Peyton Jones2020-07-286-206/+390
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Specifically: #13253 exponential inlining #10421 ditto #18140 strict constructors #18282 another nested-function call case This patch makes one really significant changes: change the way that mkDupableCont handles StrictArg. The details are explained in GHC.Core.Opt.Simplify Note [Duplicating StrictArg]. Specific changes * In mkDupableCont, when making auxiliary bindings for the other arguments of a call, add extra plumbing so that we don't forget the demand on them. Otherwise we haev to wait for another round of strictness analysis. But actually all the info is to hand. This change affects: - Make the strictness list in ArgInfo be [Demand] instead of [Bool], and rename it to ai_dmds. - Add as_dmd to ValArg - Simplify.makeTrivial takes a Demand - mkDupableContWithDmds takes a [Demand] There are a number of other small changes 1. For Ids that are used at most once in each branch of a case, make the occurrence analyser record the total number of syntactic occurrences. Previously we recorded just OneBranch or MultipleBranches. I thought this was going to be useful, but I ended up barely using it; see Note [Note [Suppress exponential blowup] in GHC.Core.Opt.Simplify.Utils Actual changes: * See the occ_n_br field of OneOcc. * postInlineUnconditionally 2. I found a small perf buglet in SetLevels; see the new function GHC.Core.Opt.SetLevels.hasFreeJoin 3. Remove the sc_cci field of StrictArg. I found I could get its information from the sc_fun field instead. Less to get wrong! 4. In ArgInfo, arrange that ai_dmds and ai_discs have a simpler invariant: they line up with the value arguments beyond ai_args This allowed a bit of nice refactoring; see isStrictArgInfo, lazyArgcontext, strictArgContext There is virtually no difference in nofib. (The runtime numbers are bogus -- I tried a few manually.) Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- fft +0.0% -2.0% -48.3% -49.4% 0.0% multiplier +0.0% -2.2% -50.3% -50.9% 0.0% -------------------------------------------------------------------------------- Min -0.4% -2.2% -59.2% -60.4% 0.0% Max +0.0% +0.1% +3.3% +4.9% 0.0% Geometric Mean +0.0% -0.0% -33.2% -34.3% -0.0% Test T18282 is an existing example of these deeply-nested strict calls. We get a big decrease in compile time (-85%) because so much less inlining takes place. Metric Decrease: T18282
* Eta-expand the Simplifier monadSimon Peyton Jones2020-07-271-6/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch eta-expands the Simplifier's monad, using the method explained in GHC.Core.Unify Note [The one-shot state monad trick]. It's part of the exta-expansion programme in #18202. It's a tiny patch, but is worth a 1-2% reduction in bytes-allocated by the compiler. Here's the list, based on the compiler-performance tests in perf/compiler: Reduction in bytes allocated T10858(normal) -0.7% T12425(optasm) -1.3% T13056(optasm) -1.8% T14683(normal) -1.1% T15164(normal) -1.3% T15630(normal) -1.4% T17516(normal) -2.3% T18282(normal) -1.6% T18304(normal) -0.8% T1969(normal) -0.6% T4801(normal) -0.8% T5321FD(normal) -0.7% T5321Fun(normal) -0.5% T5642(normal) -0.9% T6048(optasm) -1.1% T9020(optasm) -2.7% T9233(normal) -0.7% T9675(optasm) -0.5% T9961(normal) -2.9% WWRec(normal) -1.2% Metric Decrease: T12425 T9020 T9961
* Care with occCheckExpand in kind of occurrencesSimon Peyton Jones2020-07-242-21/+105
| | | | | | | | | | | | | | | | | | | Issue #18451 showed that we could get an infinite type, through over-use of occCheckExpand in the kind of an /occurrence/ of a type variable. See Note [Occurrence checking: look inside kinds] in GHC.Core.Type This patch fixes the problem by making occCheckExpand less eager to expand synonyms in kinds. It also improves pretty printing of kinds, by *not* suppressing the kind on a tyvar-binder like (a :: Const Type b) where type Const p q = p. Even though the kind of 'a' is Type, we don't want to suppress the kind ascription. Example: the error message for polykinds/T18451{a,b}. See GHC.Core.TyCo.Ppr Note [Suppressing * kinds].
* Define type Void# = (# #) (#18441)Krzysztof Gogolewski2020-07-222-5/+4
| | | | | There's one backwards compatibility issue: GHC.Prim no longer exports Void#, we now manually re-export it from GHC.Exts.
* Deprecate -fdmd-tx-dict-sel.Andreas Klebinger2020-07-221-2/+3
| | | | | | | | | | | It's behaviour is now unconditionally enabled as it's slightly beneficial. There are almost no benchmarks which benefit from disabling it, so it's not worth the keep this configurable. This fixes #18429.
* Use ShortByteString for FastStringDaniel Gröber2020-07-222-4/+7
| | | | | | | | | | | | | | | There are multiple reasons we want this: - Fewer allocations: ByteString has 3 fields, ShortByteString just has one. - ByteString memory is pinned: - This can cause fragmentation issues (see for example #13110) but also - makes using FastStrings in compact regions impossible. Metric Decrease: T5837 T12150 T12234 T12425
* Fix minor typos in a Core.hs noteChaitanya Koparkar2020-07-181-1/+1
|
* Refactor the simplification of join bindersSimon Peyton Jones2020-07-183-111/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | This MR (for #18449) refactors the Simplifier's treatment of join-point binders. Specifically, it puts together, into GHC.Core.Opt.Simplify.Env.adjustJoinPointType two currently-separate ways in which we adjust the type of a join point. As the comment says: -- (adjustJoinPointType mult new_res_ty join_id) does two things: -- -- 1. Set the return type of the join_id to new_res_ty -- See Note [Return type for join points] -- -- 2. Adjust the multiplicity of arrows in join_id's type, as -- directed by 'mult'. See Note [Scaling join point arguments] I think this actually fixes a latent bug, by ensuring that the seIdSubst and seInScope have the right multiplicity on the type of join points. I did some tidying up while I was at it. No more setJoinResTy, or modifyJoinResTy: instead it's done locally in Simplify.Env.adjustJoinPointType
* Allow multiple case branches to have a higher rank typeSimon Peyton Jones2020-07-183-29/+23
| | | | | | | | | | | | | | | | | | | | | | | As #18412 points out, it should be OK for multiple case alternatives to have a higher rank type, provided they are all the same. This patch implements that change. It sweeps away GHC.Tc.Gen.Match.tauifyMultipleBranches, and friends, replacing it with an enhanced version of fillInferResult. The basic change to fillInferResult is to permit the case in which another case alternative has already filled in the result; and in that case simply unify. It's very simple actually. See the new Note [fillInferResult] in TcMType Other refactoring: - Move all the InferResult code to one place, in GHC.Tc.Utils.TcMType (previously some of it was in Unify) - Move tcInstType and friends from TcMType to Instantiate, where it more properly belongs. (TCMType was getting very long.)
* Explain why keeping DynFlags in AnalEnv saves allocation.Andreas Klebinger2020-07-141-1/+19
|
* Reduce result discount in conSizeSimon Peyton Jones2020-07-131-16/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ticket #18282 showed that the result discount given by conSize was massively too large. This patch reduces that discount to a constant 10, which just balances the cost of the constructor application itself. Note [Constructor size and result discount] elaborates, as does the ticket #18282. Reducing result discount reduces inlining, which affects perf. I found that I could increase the unfoldingUseThrehold from 80 to 90 in compensation; in combination with the result discount change I get these overall nofib numbers: Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- boyer -0.2% +5.4% -3.2% -3.4% 0.0% cichelli -0.1% +5.9% -11.2% -11.7% 0.0% compress2 -0.2% +9.6% -6.0% -6.8% 0.0% cryptarithm2 -0.1% -3.9% -6.0% -5.7% 0.0% gamteb -0.2% +2.6% -13.8% -14.4% 0.0% genfft -0.1% -1.6% -29.5% -29.9% 0.0% gg -0.0% -2.2% -17.2% -17.8% -20.0% life -0.1% -2.2% -62.3% -63.4% 0.0% mate +0.0% +1.4% -5.1% -5.1% -14.3% parser -0.2% -2.1% +7.4% +6.7% 0.0% primetest -0.2% -12.8% -14.3% -14.2% 0.0% puzzle -0.2% +2.1% -10.0% -10.4% 0.0% rsa -0.2% -11.7% -3.7% -3.8% 0.0% simple -0.2% +2.8% -36.7% -38.3% -2.2% wheel-sieve2 -0.1% -19.2% -48.8% -49.2% -42.9% -------------------------------------------------------------------------------- Min -0.4% -19.2% -62.3% -63.4% -42.9% Max +0.3% +9.6% +7.4% +11.0% +16.7% Geometric Mean -0.1% -0.3% -17.6% -18.0% -0.7% I'm ok with these numbers, remembering that this change removes an *exponential* increase in code size in some in-the-wild cases. I investigated compress2. The difference is entirely caused by this function no longer inlining WriteRoutines.$woutputCodes = \ (w :: [CodeEvent]) -> let result_s1Sr = case WriteRoutines.outputCodes_$s$woutput w 0# 0# 8# 9# of (# ww1, ww2 #) -> (ww1, ww2) in (# case result_s1Sr of (x, _) -> map @Int @Char WriteRoutines.outputCodes1 x , case result_s1Sr of { (_, y) -> y } #) It was right on the cusp before, driven by the excessive result discount. Too bad! Happily, the compiler/perf tests show a number of improvements: T12227 compiler bytes-alloc -6.6% T12545 compiler bytes-alloc -4.7% T13056 compiler bytes-alloc -3.3% T15263 runtime bytes-alloc -13.1% T17499 runtime bytes-alloc -14.3% T3294 compiler bytes-alloc -1.1% T5030 compiler bytes-alloc -11.7% T9872a compiler bytes-alloc -2.0% T9872b compiler bytes-alloc -1.2% T9872c compiler bytes-alloc -1.5% Metric Decrease: T12227 T12545 T13056 T15263 T17499 T3294 T5030 T9872a T9872b T9872c
* Use dumpStyle when printing inliningsSimon Peyton Jones2020-07-131-1/+1
| | | | | This just makes debug-printing consistent, and more informative.
* Give Uniq[D]FM a phantom type for its key.Andreas Klebinger2020-07-125-12/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes #17667 and should help to avoid such issues going forward. The changes are mostly mechanical in nature. With two notable exceptions. * The register allocator. The register allocator references registers by distinct uniques. However they come from the types of VirtualReg, Reg or Unique in various places. As a result we sometimes cast the key type of the map and use functions which operate on the now typed map but take a raw Unique as actual key. The logic itself has not changed it just becomes obvious where we do so now. * <Type>Env Modules. As an example a ClassEnv is currently queried using the types `Class`, `Name`, and `TyCon`. This is safe since for a distinct class value all these expressions give the same unique. getUnique cls getUnique (classTyCon cls) getUnique (className cls) getUnique (tcName $ classTyCon cls) This is for the most part contained within the modules defining the interface. However it requires us to play dirty when we are given a `Name` to lookup in a `UniqFM Class a` map. But again the logic did not change and it's for the most part hidden behind the Env Module. Some of these cases could be avoided by refactoring but this is left for future work. We also bump the haddock submodule as it uses UniqFM.
* Improve eta-expansion using ArityTypeSimon Peyton Jones2020-07-113-185/+243
| | | | | | | | | | | | | | | | | | | | | | | | | | As #18355 shows, we were failing to preserve one-shot info when eta-expanding. It's rather easy to fix, by using ArityType more, rather than just Arity. This patch is important to suport the one-shot monad trick; see #18202. But the extra tracking of one-shot-ness requires the patch Define multiShotIO and use it in mkSplitUniqueSupply If that patch is missing, ths patch makes things worse in GHC.Types.Uniq.Supply. With it, however, we see these improvements T3064 compiler bytes allocated -2.2% T3294 compiler bytes allocated -1.3% T12707 compiler bytes allocated -1.3% T13056 compiler bytes allocated -2.2% Metric Decrease: T3064 T3294 T12707 T13056
* Make arityType deal with join pointsSimon Peyton Jones2020-07-101-4/+93
| | | | | | | | | | | | | | | | | | | | | | | As Note [Eta-expansion and join points] describes, this patch makes arityType deal correctly with join points. What was there before was not wrong, but yielded lower arities than it could. Fixes #18328 In base GHC this makes no difference to nofib. Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- n-body -0.1% -0.1% -1.2% -1.1% 0.0% -------------------------------------------------------------------------------- Min -0.1% -0.1% -55.0% -56.5% 0.0% Max -0.0% 0.0% +16.1% +13.4% 0.0% Geometric Mean -0.0% -0.0% -30.1% -31.0% -0.0% But it starts to make real difference when we land the change to the way mkDupableAlts handles StrictArg, in fixing #13253 and friends. I think this is because we then get more non-inlined join points.
* Define multiShotIO and use it in mkSplitUniqueSupplySimon Peyton Jones2020-07-101-13/+35
| | | | | | | | | | | | | | | | | | | | | | This patch is part of the ongoing eta-expansion saga; see #18238. It implements a neat trick (suggested by Sebastian Graf) that allows the programmer to disable the default one-shot behaviour of IO (the "state hack"). The trick is to use a new multiShotIO function; see Note [multiShotIO]. For now, multiShotIO is defined here in Unique.Supply; but it should ultimately be moved to the IO library. The change is necessary to get good code for GHC's unique supply; see Note [Optimising the unique supply]. However it makes no difference to GHC as-is. Rather, it makes a difference when a subsequent commit Improve eta-expansion using ArityType lands.
* DynFlags: avoid the use of sdocWithDynFlags in GHC.Core.Rules (#17957)Sylvain Henry2020-07-034-28/+39
|
* Improve handling of data type return kindswip/T18300Simon Peyton Jones2020-07-036-65/+227
| | | | | | | | | | | | | | | | | | Following a long conversation with Richard, this patch tidies up the handling of return kinds for data/newtype declarations (vanilla, family, and instance). I have substantially edited the Notes in TyCl, so they would bear careful reading. Fixes #18300, #18357 In GHC.Tc.Instance.Family.newFamInst we were checking some Lint-like properties with ASSSERT. Instead Richard and I have added a proper linter for axioms, and called it from lintGblEnv, which in turn is called in tcRnModuleTcRnM New tests (T18300, T18357) cause an ASSERT failure in HEAD.
* Improve debug tracing for substitutionSimon Peyton Jones2020-07-018-58/+59
| | | | | | | | | | | | This patch improves debug tracing a bit (#18395) * Remove the ancient SDoc argument to substitution, replacing it with a HasDebugCallStack constraint. The latter does the same job (indicate the call site) but much better. * Add HasDebugCallStack to simpleOptExpr, exprIsConApp_maybe I needed this to help nail the lookupIdSubst panic in #18326, #17784
* Fix a typo in LintSimon Peyton Jones2020-06-281-7/+7
| | | | | | | This simple error in GHC.Core.Litn.lintJoinLams meant that Lint reported bogus errors. Fixes #18399
* Fix duplicated words and typos in comments and user guideJan Hrček2020-06-2811-12/+12
|
* Use NHsCoreTy to embed types into GND-generated codeRyan Scott2020-06-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | `GeneralizedNewtypeDeriving` is in the unique situation where it must produce an `LHsType GhcPs` from a Core `Type`. Historically, this was done with the `typeToLHsType` function, which walked over the entire `Type` and attempted to construct an `LHsType` with the same overall structure. `typeToLHsType` is quite complicated, however, and has been the subject of numerous bugs over the years (e.g., #14579). Luckily, there is an easier way to accomplish the same thing: the `XHsType` constructor of `HsType`. `XHsType` bundles an `NHsCoreTy`, which allows embedding a Core `Type` directly into an `HsType`, avoiding the need to laboriously convert from one to another (as `typeToLHsType` did). Moreover, renaming and typechecking an `XHsType` is simple, since one doesn't need to do anything to a Core `Type`... ...well, almost. For the reasons described in `Note [Typechecking NHsCoreTys]` in `GHC.Tc.Gen.HsType`, we must apply a substitution that we build from the local `tcl_env` type environment. But that's a relatively modest price to pay. Now that `GeneralizedNewtypeDeriving` uses `NHsCoreTy`, the `typeToLHsType` function no longer has any uses in GHC, so this patch rips it out. Some additional tweaks to `hsTypeNeedsParens` were necessary to make the new `-ddump-deriv` output correctly parenthesized, but other than that, this patch is quite straightforward. This is a mostly internal refactoring, although it is likely that `GeneralizedNewtypeDeriving`-generated code will now need fewer language extensions in certain situations than it did before.
* Better loop detection in findTypeShapeSimon Peyton Jones2020-06-272-24/+38
| | | | | | | Andreas pointed out, in !3466, that my fix for #18304 was not quite right. This patch fixes it properly, by having just one RecTcChecker rather than (implicitly) two nested ones, in findTypeShape.
* Fix ghc-bignum exceptionsSylvain Henry2020-06-271-3/+36
| | | | | | | | | | | | | | | We must ensure that exceptions are not simplified. Previously we used: case raiseDivZero of _ -> 0## -- dummyValue But it was wrong because the evaluation of `raiseDivZero` was removed and the dummy value was directly returned. See new Note [ghc-bignum exceptions]. I've also removed the exception triggering primops which were fragile. We don't need them to be primops, we can have them exported by ghc-prim. I've also added a test for #18359 which triggered this patch.
* GHC.Core.Unify: Make UM actions one-shot by defaultwip/oneshot-unifySebastian Graf2020-06-251-3/+83
| | | | | | | | | | | | | This MR makes the UM monad in GHC.Core.Unify into a one-shot monad. See the long Note [The one-shot state monad trick]. See also #18202 and !3309, which applies this to all Reader/State-like monads in GHC for compile-time perf improvements. The pattern used here enables something similar to the state-hack, but is applicable to user-defined monads, not just `IO`. Metric Decrease 'runtime/bytes allocated' (test_env='i386-linux-deb9'): haddock.Cabal
* Clean up haddock hyperlinks of GHC.* (part1)Takenobu Tani2020-06-2518-61/+61
| | | | | | | | | | | | | | | | | | | This updates haddock comments only. This patch focuses to update for hyperlinks in GHC API's haddock comments, because broken links especially discourage newcomers. This includes the following hierarchies: - GHC.Hs.* - GHC.Core.* - GHC.Stg.* - GHC.Cmm.* - GHC.Types.* - GHC.Data.* - GHC.Builtin.* - GHC.Parser.* - GHC.Driver.* - GHC top
* Two small tweaks to Coercion.simplifyArgsWorkerSimon Peyton Jones2020-06-231-1/+5
| | | | | | | | | | | These tweaks affect the inner loop of simplifyArgsWorker, which in turn is called from the flattener in Flatten.hs. This is a key perf bottleneck to T9872{a,b,c,d}. These two small changes have a modest but useful benefit. No change in functionality whatsoever. Relates to #18354
View Lorry Controller Status