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* Whitespace forward compatibility for proposal #229Vladislav Zavialov2019-10-301-3/+3
| | | | | | | | GHC Proposal #229 changes the lexical rules of Haskell, which may require slight whitespace adjustments in certain cases. This patch changes formatting in a few places in GHC and its testsuite in a way that enables it to compile under the proposed rules.
* Fix bug in the x86 backend involving the CFG.Andreas Klebinger2019-10-231-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is part two of fixing #17334. There are two parts to this commit: - A bugfix for computing loop levels - A bugfix of basic block invariants in the NCG. ----------------------------------------------------------- In the first bug we ended up with a CFG of the sort: [A -> B -> C] This was represented via maps as fromList [(A,B),(B,C)] and later transformed into a adjacency array. However the transformation did not include block C in the array (since we only looked at the keys of the map). This was still fine until we tried to look up successors for C and tried to read outside of the array bounds when accessing C. In order to prevent this in the future I refactored to code to include all nodes as keys in the map representation. And make this a invariant which is checked in a few places. Overall I expect this to make the code more robust as now any failed lookup will represent an error, versus failed lookups sometimes being expected and sometimes not. In terms of performance this makes some things cheaper (getting a list of all nodes) and others more expensive (adding a new edge). Overall this adds up to no noteable performance difference. ----------------------------------------------------------- Part 2: When the NCG generated a new basic block, it did not always insert a NEWBLOCK meta instruction in the stream which caused a quite subtle bug. During instruction selection a statement `s` in a block B with control of the sort: B -> C will sometimes result in control flow of the sort: ┌ < ┐ v ^ B -> B1 ┴ -> C as is the case for some atomic operations. Now to keep the CFG in sync when introducing B1 we clearly want to insert it between B and C. However there is a catch when we have to deal with self loops. We might start with code and a CFG of these forms: loop: stmt1 ┌ < ┐ .... v ^ stmtX loop ┘ stmtY .... goto loop: Now we introduce B1: ┌ ─ ─ ─ ─ ─┐ loop: │ ┌ < ┐ │ instrs v │ │ ^ .... loop ┴ B1 ┴ ┘ instrsFromX stmtY goto loop: This is simple, all outgoing edges from loop now simply start from B1 instead and the code generator knows which new edges it introduced for the self loop of B1. Disaster strikes if the statement Y follows the same pattern. If we apply the same rule that all outgoing edges change then we end up with: loop ─> B1 ─> B2 ┬─┐ │ │ └─<┤ │ │ └───<───┘ │ └───────<────────┘ This is problematic. The edge B1->B1 is modified as expected. However the modification is wrong! The assembly in this case looked like this: _loop: <instrs> _B1: ... cmpxchgq ... jne _B1 <instrs> <end _B1> _B2: ... cmpxchgq ... jne _B2 <instrs> jmp loop There is no edge _B2 -> _B1 here. It's still a self loop onto _B1. The problem here is that really B1 should be two basic blocks. Otherwise we have control flow in the *middle* of a basic block. A contradiction! So to account for this we add yet another basic block marker: _B: <instrs> _B1: ... cmpxchgq ... jne _B1 jmp _B1' _B1': <instrs> <end _B1> _B2: ... Now when inserting B2 we will only look at the outgoing edges of B1' and everything will work out nicely. You might also wonder why we don't insert jumps at the end of _B1'. There is no way another block ends up jumping to the labels _B1 or _B2 since they are essentially invisible to other blocks. View them as control flow labels local to the basic block if you'd like. Not doing this ultimately caused (part 2 of) #17334.
* Implement a coverage checker for injectivityRichard Eisenberg2019-10-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes #16512. There are lots of parts of this patch: * The main payload is in FamInst. See Note [Coverage condition for injective type families] there for the overview. But it doesn't fix the bug. * We now bump the reduction depth every time we discharge a CFunEqCan. See Note [Flatten when discharging CFunEqCan] in TcInteract. * Exploration of this revealed a new, easy to maintain invariant for CTyEqCans. See Note [Almost function-free] in TcRnTypes. * We also realized that type inference for injectivity was a bit incomplete. This means we exchanged lookupFlattenTyVar for rewriteTyVar. See Note [rewriteTyVar] in TcFlatten. The new function is monadic while the previous one was pure, necessitating some faff in TcInteract. Nothing too bad. * zonkCt did not maintain invariants on CTyEqCan. It's not worth the bother doing so, so we just transmute CTyEqCans to CNonCanonicals. * The pure unifier was finding the fixpoint of the returned substitution, even when doing one-way matching (in tcUnifyTysWithTFs). Fixed now. Test cases: typecheck/should_fail/T16512{a,b}
* Add loop level analysis to the NCG backend.klebinger.andreas@gmx.at2019-10-162-7/+641
| | | | | | | | | | | | | | | | | | | | | | | | | | | For backends maintaining the CFG during codegen we can now find loops and their nesting level. This is based on the Cmm CFG and dominator analysis. As a result we can estimate edge frequencies a lot better for methods, resulting in far better code layout. Speedup on nofib: ~1.5% Increase in compile times: ~1.9% To make this feasible this commit adds: * Dominator analysis based on the Lengauer-Tarjan Algorithm. * An algorithm estimating global edge frequences from branch probabilities - In CFG.hs A few static branch prediction heuristics: * Expect to take the backedge in loops. * Expect to take the branch NOT exiting a loop. * Expect integer vs constant comparisons to be false. We also treat heap/stack checks special for branch prediction to avoid them being treated as loops.
* Rename STAGE macro to GHC_STAGEBen Gamari2019-10-091-3/+3
| | | | To avoid polluting the macro namespace
* Clean up `#include`s in the compilerJohn Ericson2019-10-051-3/+0
| | | | | | | | - Remove unneeded ones - Use <..> for inter-package. Besides general clean up, helps distinguish between the RTS we link against vs the RTS we compile for.
* Refactor iface file generation:Ömer Sinan Ağacan2019-09-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit refactors interface file generation to allow information from the later passed (NCG, STG) to be stored in interface files. We achieve this by splitting interface file generation into two parts: * Partial interfaces, built based on the result of the core pipeline * A fully instantiated interface, which also contains the final fingerprints and can optionally contain information produced by the backend. This change is required by !1304 and !1530. -dynamic-too handling is refactored too: previously when generating code we'd branch on -dynamic-too *before* code generation, but now we do it after. (Original code written by @AndreasK in !1530) Performance ~~~~~~~~~~~ Before this patch interface files where created and immediately flushed to disk which made space leaks impossible. With this change we instead use NFData to force all iface related data structures to avoid space leaks. In the process of refactoring it was discovered that the code in the ToIface Module allocated a lot of thunks which were immediately forced when writing/forcing the interface file. So we made this module more strict to avoid creating many of those thunks. Bottom line is that allocations go down by about ~0.1% compared to master. Residency is not meaningfully different after this patch. Runtime was not benchmarked. Co-Authored-By: Andreas Klebinger <klebinger.andreas@gmx.at> Co-Authored-By: Ömer Sinan Ağacan <omer@well-typed.com>
* PredType for type constraints in the pattern match checker instead of EvVarSebastian Graf2019-09-211-0/+6
| | | | | | | | | | | | | | | | Using EvVars for capturing type constraints implied side-effects in DsM when we just wanted to *construct* type constraints. But giving names to type constraints is only necessary when passing Givens to the type checker, of which the majority of the pattern match checker should be unaware. Thus, we simply generate `newtype TyCt = TyCt PredType`, which are nicely stateless. But at the same time this means we have to allocate EvVars when we want to query the type oracle! So we keep the type oracle state as `newtype TyState = TySt (Bag EvVar)`, which nicely makes a distinction between new, unchecked `TyCt`s and the inert set in `TyState`.
* Encode shape information in `PmOracle`Sebastian Graf2019-09-165-94/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, we had an elaborate mechanism for selecting the warnings to generate in the presence of different `COMPLETE` matching groups that, albeit finely-tuned, produced wrong results from an end user's perspective in some cases (#13363). The underlying issue is that at the point where the `ConVar` case has to commit to a particular `COMPLETE` group, there's not enough information to do so and the status quo was to just enumerate all possible complete sets nondeterministically. The `getResult` function would then pick the outcome according to metrics defined in accordance to the user's guide. But crucially, it lacked knowledge about the order in which affected clauses appear, leading to the surprising behavior in #13363. In !1010 we taught the term oracle to reason about literal values a variable can certainly not take on. This MR extends that idea to `ConLike`s and thereby fixes #13363: Instead of committing to a particular `COMPLETE` group in the `ConVar` case, we now split off the matching constructor incrementally and record the newly covered case as a refutable shape in the oracle. Whenever the set of refutable shapes covers any `COMPLETE` set, the oracle recognises vacuosity of the uncovered set. This patch goes a step further: Since at this point the information in value abstractions is merely a cut down representation of what the oracle knows, value abstractions degenerate to a single `Id`, the semantics of which is determined by the oracle state `Delta`. Value vectors become lists of `[Id]` given meaning to by a single `Delta`, value set abstractions (of which the uncovered set is an instance) correspond to a union of `Delta`s which instantiate the same `[Id]` (akin to models of formula). Fixes #11528 #13021, #13363, #13965, #14059, #14253, #14851, #15753, #17096, #17149 ------------------------- Metric Decrease: ManyAlternatives T11195 -------------------------
* Compiler should always get fingerprinting impl from baseJohn Ericson2019-09-132-20/+1
| | | | | 07ee15915d5a0d6d1aeee137541eec6e9c153e65 started the transition, but the job was never finished.
* Remove dead `ncgDebugIsOn` and `NCG_DEBUG`John Ericson2019-09-111-8/+1
| | | | Haven't been used since 16206a6603e87e15d61c57456267c5f7ba68050e.
* Update FastString docstringsDaniel Gröber2019-09-091-8/+10
| | | | | | 1) FastStrings are always UTF-8 encoded now. 2) Clarify what is meant by "hashed" 3) Add mention of lazy z-enc
* Use lazyness for FastString's z-encoding memoizationDaniel Gröber2019-09-091-41/+37
| | | | | | | | | | | | | | | | | | | Having an IORef in FastString to memoize the z-encoded version is unecessary because there is this amazing thing Haskell can do natively, it's called "lazyness" :) We simply remove the UNPACK and strictness annotations from the constructor field corresponding to the z-encoding, making it lazy, and store the (pure) z-encoded string there. The only complication here is 'hasZEncoding' which allows cheking if a z-encoding was computed for a given string. Since this is only used for compiler performance statistics though it's not actually necessary to have the current per-string granularity. Instead I add a global IORef counter to the FastStringTable and use unsafePerformIO to increment the counter whenever a lazy z-encoding is forced.
* Fix GHC version guard for Int32Rep/Word32RepMoritz Kiefer2019-09-081-0/+4
| | | | | Those constructors have been added after GHC 8.8. The version guards in `binary` are correct, see https://github.com/kolmodin/binary/pull/167/files.
* Return results of Cmm streams in backendsÖmer Sinan Ağacan2019-08-281-2/+22
| | | | | | | | | | | | | | | | | | | This generalizes code generators (outputAsm, outputLlvm, outputC, and the call site codeOutput) so that they'll return the return values of the passed Cmm streams. This allows accumulating data during Cmm generation and returning it to the call site in HscMain. Previously the Cmm streams were assumed to return (), so the code generators returned () as well. This change is required by !1304 and !1530. Skipping CI as this was tested before and I only updated the commit message. [skip ci]
* Use variable length encoding for Binary instances.Andreas Klebinger2019-08-231-95/+246
| | | | | | | | Use LEB128 encoding for Int/Word variants. This reduces the size of interface files significantly. (~19%). Also includes a few small optimizations to make unboxing work better that I have noticed while looking at the core.
* Make non-streaming LLVM and C backends streamingÖmer Sinan Ağacan2019-08-231-1/+10
| | | | | | | | | This adds a Stream.consume function, uses it in LLVM and C code generators, and removes the use of Stream.collect function which was used to collect streaming Cmm generation results into a list. LLVM and C backends now properly use streamed Cmm generation, instead of collecting Cmm groups into a list before generating LLVM/C code.
* Remove Bag fold specialisations (#16969)Richard Lupton2019-08-191-29/+5
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* Use Foldable instance of Bag for specialised Bag folds (#16969)Richard Lupton2019-08-191-19/+26
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* Re-export foldlM and foldrM from Data.Foldable in MonadUtils (#16969)Richard Lupton2019-08-191-9/+1
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* Generalized MonadUtils folds to Foldable (#16969)Richard Lupton2019-08-191-6/+5
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* Faster exactLog2Sylvain Henry2019-08-181-14/+8
| | | | | | Make `exactLog2` faster (use `countLeadingZeros` and Int32 bit-ops). On my Core i7-9700k Criterion reports ~50% speedup (from 16 to 8ns).
* Rework the Binary Integer instance.Andreas Klebinger2019-08-141-22/+74
| | | | | | | | | | | | We used to serialise large integers as strings. Now they are serialized as a list of Bytes. This changes the size for a Integer in the higher 64bit range from 77 to 9 bytes when written to disk. The impact on the general case is small (<1% for interface files) as we don't use many Integers. But for code that uses many this should be a nice benefit.
* Add Foldable, Traversable instances for Uniq(D)FMSebastian Graf2019-08-132-4/+38
| | | | | The `UniqDFM` is deterministic, of course, while we provide an unsafe `NonDetUniqFM` wrapper for `UniqFM` to opt into nondeterministic instances.
* Add HasDebugCallStack to unionListsBen Gamari2019-07-181-1/+1
| | | | This should help identify a few cases where this is throwing warnings
* Create {Int,Word}32RepJohn Ericson2019-07-171-0/+4
| | | | | | | This prepares the way for making Int32# and Word32# the actual size they claim to be. Updates binary submodule for (de)serializing the new runtime reps.
* Expunge #ifdef and #ifndef from the codebaseJohn Ericson2019-07-141-1/+1
| | | | | | | | These are unexploded minds as far as the linter is concerned. I don't want to hit in my MRs by mistake! I did this with `sed`, and then rolled back some changes in the docs, config.guess, and the linter itself.
* Special case a few common patterns in unionLists.Andreas Klebinger2019-07-111-1/+10
| | | | | | | In particular we very often pass one empty list and in these cases we want to avoid the overhead of computing `xs ++ []`. This should fix #14759 and #16911.
* ghc-pkg needs settings file to un-hardcode target platformJohn Ericson2019-06-191-22/+0
| | | | This matches GHC itself getting the target platform from there.
* Move 'Platform' to ghc-bootJohn Ericson2019-06-193-192/+2
| | | | | | | ghc-pkg needs to be aware of platforms so it can figure out which subdire within the user package db to use. This is admittedly roundabout, but maybe Cabal could use the same notion of a platform as GHC to good affect too.
* Remove dead codeKrzysztof Gogolewski2019-06-151-23/+0
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* Add Outputable instances for Float, Double.Andreas Klebinger2019-06-131-0/+6
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* Use DeriveFunctor throughout the codebase (#15654)Krzysztof Gogolewski2019-06-128-37/+17
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* Refine the GHCI macro into HAVE[_{INTERNAL, EXTERNAL}]_INTERPRETERAlp Mestanogullari2019-06-111-1/+1
| | | | | | | | | | | | | | | | | As discussed in #16331, the GHCI macro, defined through 'ghci' flags in ghc.cabal.in, ghc-bin.cabal.in and ghci.cabal.in, is supposed to indicate whether GHC is built with support for an internal interpreter, that runs in the same process. It is however overloaded in a few places to mean "there is an interpreter available", regardless of whether it's an internal or external interpreter. For the sake of clarity and with the hope of more easily being able to build stage 1 GHCs with external interpreter support, this patch splits the previous GHCI macro into 3 different ones: - HAVE_INTERNAL_INTERPRETER: GHC is built with an internal interpreter - HAVE_EXTERNAL_INTERPRETER: GHC is built with support for external interpreters - HAVE_INTERPRETER: HAVE_INTERNAL_INTERPRETER || HAVE_EXTERNAL_INTERPRETER
* TmOracle: Replace negative term equalities by refutable PmAltConsSebastian Graf2019-06-071-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | The `PmExprEq` business was a huge hack and was at the same time vastly too powerful and not powerful enough to encode negative term equalities, i.e. facts of the form "forall y. x ≁ Just y". This patch introduces the concept of 'refutable shapes': What matters for the pattern match checker is being able to encode knowledge of the kind "x can no longer be the literal 5". We encode this knowledge in a `PmRefutEnv`, mapping a set of newly introduced `PmAltCon`s (which are just `PmLit`s at the moment) to each variable denoting above inequalities. So, say we have `x ≁ 42 ∈ refuts` in the term oracle context and try to solve an equality like `x ~ 42`. The entry in the refutable environment will immediately lead to a contradiction. This machinery renders the whole `PmExprEq` and `ComplexEq` business unnecessary, getting rid of a lot of (mostly dead) code. See the Note [Refutable shapes] in TmOracle for a place to start. Metric Decrease: T11195
* Break up `Settings` into smaller structsJohn Ericson2019-05-291-0/+28
| | | | | | | | | | | | | | | | | As far as I can tell, the fields within `Settings` aren't *intrinsicly* related. They just happen to be initialized the same way (in particular prior to the rest of `DynFlags`), and that is why they are grouped together. Within `Settings`, however, there are groups of settings that clearly do share something in common, regardless of how they anything is initialized. In the spirit of GHC being a library, where the end cosumer may choose to initialize this configuration in arbitrary ways, I made some new data types for thoses groups internal to `Settings`, and used them to define `Settings` instead. Hopefully this is a baby step towards a general decoupling of the stateful and stateless parts of GHC.
* Add hPutStringBuffer utilityDaniel Gröber2019-05-291-0/+6
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* Fix missing unboxed tuple RuntimeReps (#16565)Krzysztof Gogolewski2019-05-291-7/+1
| | | | | | | | | | | | | Unboxed tuples and sums take extra RuntimeRep arguments, which must be manually passed in a few places. This was not done in deSugar/Check. This error was hidden because zipping functions in TyCoRep ignored lists with mismatching length. This is now fixed; the lengths are now checked by calling zipEqual. As suggested in #16565, I moved checking for isTyVar and isCoVar to zipTyEnv and zipCoEnv.
* Add a pprTraceWith functionSebastian Graf2019-05-271-3/+9
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* Add PlainPanic for throwing exceptions without depending on pprintMichael Sloan2019-05-247-93/+174
| | | | | | | | | | | | | | | | | | | | | This commit splits out a subset of GhcException which do not depend on pretty printing (SDoc), as a new datatype called PlainGhcException. These exceptions can be caught as GhcException, because 'fromException' will convert them. The motivation for this change is that that the Panic module transitively depends on many modules, primarily due to pretty printing code. It's on the order of about 130 modules. This large set of dependencies has a few implications: 1. To avoid cycles / use of boot files, these dependencies cannot throw GhcException. 2. There are some utility modules that use UnboxedTuples and also use `panic`. This means that when loading GHC into GHCi, about 130 additional modules would need to be compiled instead of interpreted. Splitting the non-pprint exception throwing into a new module resolves this issue. See #13101
* Purge TargetPlatform_NAME and cTargetPlatformStringJohn Ericson2019-05-081-2/+2
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* Add an Outputable instance for SDoc with ppr = id.klebinger.andreas@gmx.at2019-04-171-0/+4
| | | | When printf debugging this can be helpful.
* codegen: use newtype for Alignment in BasicTypesArtem Pyanykh2019-04-091-11/+0
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* codegen: fix memset unroll for small bytearrays, add 64-bit setsArtem Pyanykh2019-04-091-0/+10
| | | | | | | | | | | | | | | | | | | | | | Fixes #16052 When the offset in `setByteArray#` is statically known, we can provide better alignment guarantees then just 1 byte. Also, memset can now do 64-bit wide sets. The current memset intrinsic is not optimal however and can be improved for the case when we know that we deal with (baseAddress at known alignment) + offset For instance, on 64-bit `setByteArray# s 1# 23# 0#` given that bytearray is 8 bytes aligned could be unrolled into `movb, movw, movl, movq, movq`; but currently it is `movb x23` since alignment of 1 is all we can embed into MO_Memset op.
* Remove unnecessary uses of UnboxedTuples pragma (see #13101 / #15454)Michael Sloan2019-04-011-1/+1
| | | | Also removes a couple unnecessary MagicHash pragmas
* Update Wiki URLs to point to GitLabTakenobu Tani2019-03-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | This moves all URL references to Trac Wiki to their corresponding GitLab counterparts. This substitution is classified as follows: 1. Automated substitution using sed with Ben's mapping rule [1] Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy... New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy... 2. Manual substitution for URLs containing `#` index Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy...#Zzz New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy...#zzz 3. Manual substitution for strings starting with `Commentary` Old: Commentary/XxxYyy... New: commentary/xxx-yyy... See also !539 [1]: https://gitlab.haskell.org/bgamari/gitlab-migration/blob/master/wiki-mapping.json
* Replace nOfThem by replicateKrzysztof Gogolewski2019-03-191-4/+1
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* compiler: Disable atomic renaming on WindowsBen Gamari2019-03-161-1/+13
| | | | | As discussed in #16450, this feature regresses CI on Windows, causing non-deterministic failures due to missing files.
* Update Trac ticket URLs to point to GitLabRyan Scott2019-03-153-4/+4
| | | | | This moves all URL references to Trac tickets to their corresponding GitLab counterparts.
* NCG: correctly escape path strings on Windows (#16389)Sylvain Henry2019-03-091-1/+11
| | | | | GHC native code generator generates .incbin and .file directives. We need to escape those strings correctly on Windows (see #16389).