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* Modules: CmmToAsm (#13009)Sylvain Henry2020-02-2421-6072/+0
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* Modules: Driver (#13009)Sylvain Henry2020-02-218-8/+8
| | | | submodule updates: nofib, haddock
* Use concatMap(M) instead of `concat . map` and the monadic variantÖmer Sinan Ağacan2020-02-202-2/+4
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* Do CafInfo/SRT analysis in CmmÖmer Sinan Ağacan2020-01-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes all CafInfo predictions and various hacks to preserve predicted CafInfos from the compiler and assigns final CafInfos to interface Ids after code generation. SRT analysis is extended to support static data, and Cmm generator is modified to allow generating static_link fields after SRT analysis. This also fixes `-fcatch-bottoms`, which introduces error calls in case expressions in CorePrep, which runs *after* CoreTidy (which is where we decide on CafInfos) and turns previously non-CAFFY things into CAFFY. Fixes #17648 Fixes #9718 Evaluation ========== NoFib ----- Boot with: `make boot mode=fast` Run: `make mode=fast EXTRA_RUNTEST_OPTS="-cachegrind" NoFibRuns=1` -------------------------------------------------------------------------------- Program Size Allocs Instrs Reads Writes -------------------------------------------------------------------------------- CS -0.0% 0.0% -0.0% -0.0% -0.0% CSD -0.0% 0.0% -0.0% -0.0% -0.0% FS -0.0% 0.0% -0.0% -0.0% -0.0% S -0.0% 0.0% -0.0% -0.0% -0.0% VS -0.0% 0.0% -0.0% -0.0% -0.0% VSD -0.0% 0.0% -0.0% -0.0% -0.5% VSM -0.0% 0.0% -0.0% -0.0% -0.0% anna -0.1% 0.0% -0.0% -0.0% -0.0% ansi -0.0% 0.0% -0.0% -0.0% -0.0% atom -0.0% 0.0% -0.0% -0.0% -0.0% awards -0.0% 0.0% -0.0% -0.0% -0.0% banner -0.0% 0.0% -0.0% -0.0% -0.0% bernouilli -0.0% 0.0% -0.0% -0.0% -0.0% binary-trees -0.0% 0.0% -0.0% -0.0% -0.0% boyer -0.0% 0.0% -0.0% -0.0% -0.0% boyer2 -0.0% 0.0% -0.0% -0.0% -0.0% bspt -0.0% 0.0% -0.0% -0.0% -0.0% cacheprof -0.0% 0.0% -0.0% -0.0% -0.0% calendar -0.0% 0.0% -0.0% -0.0% -0.0% cichelli -0.0% 0.0% -0.0% -0.0% -0.0% circsim -0.0% 0.0% -0.0% -0.0% -0.0% clausify -0.0% 0.0% -0.0% -0.0% -0.0% comp_lab_zift -0.0% 0.0% -0.0% -0.0% -0.0% compress -0.0% 0.0% -0.0% -0.0% -0.0% compress2 -0.0% 0.0% -0.0% -0.0% -0.0% constraints -0.0% 0.0% -0.0% -0.0% -0.0% cryptarithm1 -0.0% 0.0% -0.0% -0.0% -0.0% cryptarithm2 -0.0% 0.0% -0.0% -0.0% -0.0% cse -0.0% 0.0% -0.0% -0.0% -0.0% digits-of-e1 -0.0% 0.0% -0.0% -0.0% -0.0% digits-of-e2 -0.0% 0.0% -0.0% -0.0% -0.0% dom-lt -0.0% 0.0% -0.0% -0.0% -0.0% eliza -0.0% 0.0% -0.0% -0.0% -0.0% event -0.0% 0.0% -0.0% -0.0% -0.0% exact-reals -0.0% 0.0% -0.0% -0.0% -0.0% exp3_8 -0.0% 0.0% -0.0% -0.0% -0.0% expert -0.0% 0.0% -0.0% -0.0% -0.0% fannkuch-redux -0.0% 0.0% -0.0% -0.0% -0.0% fasta -0.0% 0.0% -0.0% -0.0% -0.0% fem -0.0% 0.0% -0.0% -0.0% -0.0% fft -0.0% 0.0% -0.0% -0.0% -0.0% fft2 -0.0% 0.0% -0.0% -0.0% -0.0% fibheaps -0.0% 0.0% -0.0% -0.0% -0.0% fish -0.0% 0.0% -0.0% -0.0% -0.0% fluid -0.1% 0.0% -0.0% -0.0% -0.0% fulsom -0.0% 0.0% -0.0% -0.0% -0.0% gamteb -0.0% 0.0% -0.0% -0.0% -0.0% gcd -0.0% 0.0% -0.0% -0.0% -0.0% gen_regexps -0.0% 0.0% -0.0% -0.0% -0.0% genfft -0.0% 0.0% -0.0% -0.0% -0.0% gg -0.0% 0.0% -0.0% -0.0% -0.0% grep -0.0% 0.0% -0.0% -0.0% -0.0% hidden -0.0% 0.0% -0.0% -0.0% -0.0% hpg -0.1% 0.0% -0.0% -0.0% -0.0% ida -0.0% 0.0% -0.0% -0.0% -0.0% infer -0.0% 0.0% -0.0% -0.0% -0.0% integer -0.0% 0.0% -0.0% -0.0% -0.0% integrate -0.0% 0.0% -0.0% -0.0% -0.0% k-nucleotide -0.0% 0.0% -0.0% -0.0% -0.0% kahan -0.0% 0.0% -0.0% -0.0% -0.0% knights -0.0% 0.0% -0.0% -0.0% -0.0% lambda -0.0% 0.0% -0.0% -0.0% -0.0% last-piece -0.0% 0.0% -0.0% -0.0% -0.0% lcss -0.0% 0.0% -0.0% -0.0% -0.0% life -0.0% 0.0% -0.0% -0.0% -0.0% lift -0.0% 0.0% -0.0% -0.0% -0.0% linear -0.1% 0.0% -0.0% -0.0% -0.0% listcompr -0.0% 0.0% -0.0% -0.0% -0.0% listcopy -0.0% 0.0% -0.0% -0.0% -0.0% maillist -0.0% 0.0% -0.0% -0.0% -0.0% mandel -0.0% 0.0% -0.0% -0.0% -0.0% mandel2 -0.0% 0.0% -0.0% -0.0% -0.0% mate -0.0% 0.0% -0.0% -0.0% -0.0% minimax -0.0% 0.0% -0.0% -0.0% -0.0% mkhprog -0.0% 0.0% -0.0% -0.0% -0.0% multiplier -0.0% 0.0% -0.0% -0.0% -0.0% n-body -0.0% 0.0% -0.0% -0.0% -0.0% nucleic2 -0.0% 0.0% -0.0% -0.0% -0.0% para -0.0% 0.0% -0.0% -0.0% -0.0% paraffins -0.0% 0.0% -0.0% -0.0% -0.0% parser -0.1% 0.0% -0.0% -0.0% -0.0% parstof -0.1% 0.0% -0.0% -0.0% -0.0% pic -0.0% 0.0% -0.0% -0.0% -0.0% pidigits -0.0% 0.0% -0.0% -0.0% -0.0% power -0.0% 0.0% -0.0% -0.0% -0.0% pretty -0.0% 0.0% -0.3% -0.4% -0.4% primes -0.0% 0.0% -0.0% -0.0% -0.0% primetest -0.0% 0.0% -0.0% -0.0% -0.0% prolog -0.0% 0.0% -0.0% -0.0% -0.0% puzzle -0.0% 0.0% -0.0% -0.0% -0.0% queens -0.0% 0.0% -0.0% -0.0% -0.0% reptile -0.0% 0.0% -0.0% -0.0% -0.0% reverse-complem -0.0% 0.0% -0.0% -0.0% -0.0% rewrite -0.0% 0.0% -0.0% -0.0% -0.0% rfib -0.0% 0.0% -0.0% -0.0% -0.0% rsa -0.0% 0.0% -0.0% -0.0% -0.0% scc -0.0% 0.0% -0.3% -0.5% -0.4% sched -0.0% 0.0% -0.0% -0.0% -0.0% scs -0.0% 0.0% -0.0% -0.0% -0.0% simple -0.1% 0.0% -0.0% -0.0% -0.0% solid -0.0% 0.0% -0.0% -0.0% -0.0% sorting -0.0% 0.0% -0.0% -0.0% -0.0% spectral-norm -0.0% 0.0% -0.0% -0.0% -0.0% sphere -0.0% 0.0% -0.0% -0.0% -0.0% symalg -0.0% 0.0% -0.0% -0.0% -0.0% tak -0.0% 0.0% -0.0% -0.0% -0.0% transform -0.0% 0.0% -0.0% -0.0% -0.0% treejoin -0.0% 0.0% -0.0% -0.0% -0.0% typecheck -0.0% 0.0% -0.0% -0.0% -0.0% veritas -0.0% 0.0% -0.0% -0.0% -0.0% wang -0.0% 0.0% -0.0% -0.0% -0.0% wave4main -0.0% 0.0% -0.0% -0.0% -0.0% wheel-sieve1 -0.0% 0.0% -0.0% -0.0% -0.0% wheel-sieve2 -0.0% 0.0% -0.0% -0.0% -0.0% x2n1 -0.0% 0.0% -0.0% -0.0% -0.0% -------------------------------------------------------------------------------- Min -0.1% 0.0% -0.3% -0.5% -0.5% Max -0.0% 0.0% -0.0% -0.0% -0.0% Geometric Mean -0.0% -0.0% -0.0% -0.0% -0.0% -------------------------------------------------------------------------------- Program Size Allocs Instrs Reads Writes -------------------------------------------------------------------------------- circsim -0.1% 0.0% -0.0% -0.0% -0.0% constraints -0.0% 0.0% -0.0% -0.0% -0.0% fibheaps -0.0% 0.0% -0.0% -0.0% -0.0% gc_bench -0.0% 0.0% -0.0% -0.0% -0.0% hash -0.0% 0.0% -0.0% -0.0% -0.0% lcss -0.0% 0.0% -0.0% -0.0% -0.0% power -0.0% 0.0% -0.0% -0.0% -0.0% spellcheck -0.0% 0.0% -0.0% -0.0% -0.0% -------------------------------------------------------------------------------- Min -0.1% 0.0% -0.0% -0.0% -0.0% Max -0.0% 0.0% -0.0% -0.0% -0.0% Geometric Mean -0.0% +0.0% -0.0% -0.0% -0.0% Manual inspection of programs in testsuite/tests/programs --------------------------------------------------------- I built these programs with a bunch of dump flags and `-O` and compared STG, Cmm, and Asm dumps and file sizes. (Below the numbers in parenthesis show number of modules in the program) These programs have identical compiler (same .hi and .o sizes, STG, and Cmm and Asm dumps): - Queens (1), andre_monad (1), cholewo-eval (2), cvh_unboxing (3), andy_cherry (7), fun_insts (1), hs-boot (4), fast2haskell (2), jl_defaults (1), jq_readsPrec (1), jules_xref (1), jtod_circint (4), jules_xref2 (1), lennart_range (1), lex (1), life_space_leak (1), bargon-mangler-bug (7), record_upd (1), rittri (1), sanders_array (1), strict_anns (1), thurston-module-arith (2), okeefe_neural (1), joao-circular (6), 10queens (1) Programs with different compiler outputs: - jl_defaults (1): For some reason GHC HEAD marks a lot of top-level `[Int]` closures as CAFFY for no reason. With this patch we no longer make them CAFFY and generate less SRT entries. For some reason Main.o is slightly larger with this patch (1.3%) and the executable sizes are the same. (I'd expect both to be smaller) - launchbury (1): Same as jl_defaults: top-level `[Int]` closures marked as CAFFY for no reason. Similarly `Main.o` is 1.4% larger but the executable sizes are the same. - galois_raytrace (13): Differences are in the Parse module. There are a lot, but some of the changes are caused by the fact that for some reason (I think a bug) GHC HEAD marks the dictionary for `Functor Identity` as CAFFY. Parse.o is 0.4% larger, the executable size is the same. - north_array: We now generate less SRT entries because some of array primops used in this program like `NewArrayOp` get eliminated during Stg-to-Cmm and turn some CAFFY things into non-CAFFY. Main.o gets 24% larger (9224 bytes from 9000 bytes), executable sizes are the same. - seward-space-leak: Difference in this program is better shown by this smaller example: module Lib where data CDS = Case [CDS] [(Int, CDS)] | Call CDS CDS instance Eq CDS where Case sels1 rets1 == Case sels2 rets2 = sels1 == sels2 && rets1 == rets2 Call a1 b1 == Call a2 b2 = a1 == a2 && b1 == b2 _ == _ = False In this program GHC HEAD builds a new SRT for the recursive group of `(==)`, `(/=)` and the dictionary closure. Then `/=` points to `==` in its SRT field, and `==` uses the SRT object as its SRT. With this patch we use the closure for `/=` as the SRT and add `==` there. Then `/=` gets an empty SRT field and `==` points to `/=` in its SRT field. This change looks fine to me. Main.o gets 0.07% larger, executable sizes are identical. head.hackage ------------ head.hackage's CI script builds 428 packages from Hackage using this patch with no failures. Compiler performance -------------------- The compiler perf tests report that the compiler allocates slightly more (worst case observed so far is 4%). However most programs in the test suite are small, single file programs. To benchmark compiler performance on something more realistic I build Cabal (the library, 236 modules) with different optimisation levels. For the "max residency" row I run GHC with `+RTS -s -A100k -i0 -h` for more accurate numbers. Other rows are generated with just `-s`. (This is because `-i0` causes running GC much more frequently and as a result "bytes copied" gets inflated by more than 25x in some cases) * -O0 | | GHC HEAD | This MR | Diff | | --------------- | -------------- | -------------- | ------ | | Bytes allocated | 54,413,350,872 | 54,701,099,464 | +0.52% | | Bytes copied | 4,926,037,184 | 4,990,638,760 | +1.31% | | Max residency | 421,225,624 | 424,324,264 | +0.73% | * -O1 | | GHC HEAD | This MR | Diff | | --------------- | --------------- | --------------- | ------ | | Bytes allocated | 245,849,209,992 | 246,562,088,672 | +0.28% | | Bytes copied | 26,943,452,560 | 27,089,972,296 | +0.54% | | Max residency | 982,643,440 | 991,663,432 | +0.91% | * -O2 | | GHC HEAD | This MR | Diff | | --------------- | --------------- | --------------- | ------ | | Bytes allocated | 291,044,511,408 | 291,863,910,912 | +0.28% | | Bytes copied | 37,044,237,616 | 36,121,690,472 | -2.49% | | Max residency | 1,071,600,328 | 1,086,396,256 | +1.38% | Extra compiler allocations -------------------------- Runtime allocations of programs are as reported above (NoFib section). The compiler now allocates more than before. Main source of allocation in this patch compared to base commit is the new SRT algorithm (GHC.Cmm.Info.Build). Below is some of the extra work we do with this patch, numbers generated by profiled stage 2 compiler when building a pathological case (the test 'ManyConstructors') with '-O2': - We now sort the final STG for a module, which means traversing the entire program, generating free variable set for each top-level binding, doing SCC analysis, and re-ordering the program. In ManyConstructors this step allocates 97,889,952 bytes. - We now do SRT analysis on static data, which in a program like ManyConstructors causes analysing 10,000 bindings that we would previously just skip. This step allocates 70,898,352 bytes. - We now maintain an SRT map for the entire module as we compile Cmm groups: data ModuleSRTInfo = ModuleSRTInfo { ... , moduleSRTMap :: SRTMap } (SRTMap is just a strict Map from the 'containers' library) This map gets an entry for most bindings in a module (exceptions are THUNKs and CAFFY static functions). For ManyConstructors this map gets 50015 entries. - Once we're done with code generation we generate a NameSet from SRTMap for the non-CAFFY names in the current module. This set gets the same number of entries as the SRTMap. - Finally we update CafInfos in ModDetails for the non-CAFFY Ids, using the NameSet generated in the previous step. This usually does the least amount of allocation among the work listed here. Only place with this patch where we do less work in the CAF analysis in the tidying pass (CoreTidy). However that doesn't save us much, as the pass still needs to traverse the whole program and update IdInfos for other reasons. Only thing we don't here do is the `hasCafRefs` pass over the RHS of bindings, which is a stateless pass that returns a boolean value, so it doesn't allocate much. (Metric changes blow are all increased allocations) Metric changes -------------- Metric Increase: ManyAlternatives ManyConstructors T13035 T14683 T1969 T9961
* Disable two warnings for files that trigger themTom Ellis2020-01-274-0/+7
| | | | | | incomplete-uni-patterns and incomplete-record-updates will be in -Wall at a future date, so prepare for that by disabling those warnings on files that trigger them.
* Module hierarchy: Cmm (cf #13009)Sylvain Henry2020-01-259-22/+22
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* PmCheck: Formulate as translation between Clause TreesSebastian Graf2020-01-253-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We used to check `GrdVec`s arising from multiple clauses and guards in isolation. That resulted in a split between `pmCheck` and `pmCheckGuards`, the implementations of which were similar, but subtly different in detail. Also the throttling mechanism described in `Note [Countering exponential blowup]` ultimately got quite complicated because it had to cater for both checking functions. This patch realises that pattern match checking doesn't just consider single guarded RHSs, but that it's always a whole set of clauses, each of which can have multiple guarded RHSs in turn. We do so by translating a list of `Match`es to a `GrdTree`: ```haskell data GrdTree = Rhs !RhsInfo | Guard !PmGrd !GrdTree -- captures lef-to-right match semantics | Sequence !GrdTree !GrdTree -- captures top-to-bottom match semantics | Empty -- For -XEmptyCase, neutral element of Sequence ``` Then we have a function `checkGrdTree` that matches a given `GrdTree` against an incoming set of values, represented by `Deltas`: ```haskell checkGrdTree :: GrdTree -> Deltas -> CheckResult ... ``` Throttling is isolated to the `Sequence` case and becomes as easy as one would expect: When the union of uncovered values becomes too big, just return the original incoming `Deltas` instead (which is always a superset of the union, thus a sound approximation). The returned `CheckResult` contains two things: 1. The set of values that were not covered by any of the clauses, for exhaustivity warnings. 2. The `AnnotatedTree` that enriches the syntactic structure of the input program with divergence and inaccessibility information. This is `AnnotatedTree`: ```haskell data AnnotatedTree = AccessibleRhs !RhsInfo | InaccessibleRhs !RhsInfo | MayDiverge !AnnotatedTree | SequenceAnn !AnnotatedTree !AnnotatedTree | EmptyAnn ``` Crucially, `MayDiverge` asserts that the tree may force diverging values, so not all of its wrapped clauses can be redundant. While the set of uncovered values can be used to generate the missing equations for warning messages, redundant and proper inaccessible equations can be extracted from `AnnotatedTree` by `redundantAndInaccessibleRhss`. For this to work properly, the interface to the Oracle had to change. There's only `addPmCts` now, which takes a bag of `PmCt`s. There's a whole bunch of `PmCt` variants to replace the different oracle functions from before. The new `AnnotatedTree` structure allows for more accurate warning reporting (as evidenced by a number of changes spread throughout GHC's code base), thus we fix #17465. Fixes #17646 on the go. Metric Decrease: T11822 T9233 PmSeriesS haddock.compiler
* Fix typos, via a Levenshtein-style correctorBrian Wignall2020-01-043-3/+3
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* Fix typos, using Wikipedia list of common typosBrian Wignall2019-11-282-2/+2
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* Fix bug in the x86 backend involving the CFG.Andreas Klebinger2019-10-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 s390x LLVM backend.Stefan Schulze Frielinghaus2019-10-223-0/+5
| | | | | | This patch adds support for the s390x architecture for the LLVM code generator. The patch includes a register mapping of STG registers onto s390x machine registers which enables a registerised build.
* Add loop level analysis to the NCG backend.klebinger.andreas@gmx.at2019-10-161-47/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Remove empty NCG.hJohn Ericson2019-09-131-2/+0
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* Module hierarchy: StgToCmm (#13009)Sylvain Henry2019-09-101-1/+1
| | | | | | Add StgToCmm module hierarchy. Platform modules that are used in several other places (NCG, LLVM codegen, Cmm transformations) are put into GHC.Platform.
* Remove Bag fold specialisations (#16969)Richard Lupton2019-08-191-2/+2
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* Remove unused imports of the form 'import foo ()' (Fixes #17065)James Foster2019-08-152-2/+0
| | | | | | | | | | | These kinds of imports are necessary in some cases such as importing instances of typeclasses or intentionally creating dependencies in the build system, but '-Wunused-imports' can't detect when they are no longer needed. This commit removes the unused ones currently in the code base (not including test files or submodules), with the hope that doing so may increase parallelism in the build system by removing unnecessary dependencies.
* Revert "Add support for SIMD operations in the NCG"Ben Gamari2019-07-163-9/+3
| | | | | | | Unfortunately this will require more work; register allocation is quite broken. This reverts commit acd795583625401c5554f8e04ec7efca18814011.
* Add support for SIMD operations in the NCGAbhiroop Sarkar2019-07-033-3/+9
| | | | | | | This adds support for constructing vector types from Float#, Double# etc and performing arithmetic operations on them Cleaned-Up-By: Ben Gamari <ben@well-typed.com>
* Move 'Platform' to ghc-bootJohn Ericson2019-06-1912-12/+12
| | | | | | | 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.
* Use DeriveFunctor throughout the codebase (#15654)Krzysztof Gogolewski2019-06-121-5/+4
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* Use datatype for unboxed returns when loading ghc into ghciMichael Sloan2019-05-221-25/+39
| | | | See #13101 and #15454
* removing x87 register support from native code genCarter Schonwald2019-04-101-26/+12
| | | | | | | | | | | | | | | | * simplifies registers to have GPR, Float and Double, by removing the SSE2 and X87 Constructors * makes -msse2 assumed/default for x86 platforms, fixing a long standing nondeterminism in rounding behavior in 32bit haskell code * removes the 80bit floating point representation from the supported float sizes * theres still 1 tiny bit of x87 support needed, for handling float and double return values in FFI calls wrt the C ABI on x86_32, but this one piece does not leak into the rest of NCG. * Lots of code thats not been touched in a long time got deleted as a consequence of all of this all in all, this change paves the way towards a lot of future further improvements in how GHC handles floating point computations, along with making the native code gen more accessible to a larger pool of contributors.
* Rip out object splittingBen Gamari2019-03-051-4/+0
| | | | | | | | | | | | | | | The splitter is an evil Perl script that processes assembler code. Its job can be done better by the linker's --gc-sections flag. GHC passes this flag to the linker whenever -split-sections is passed on the command line. This is based on @DemiMarie's D2768. Fixes Trac #11315 Fixes Trac #9832 Fixes Trac #8964 Fixes Trac #8685 Fixes Trac #8629
* Don't wrap the entry map for LiveInfo in Maybe.klebinger.andreas@gmx.at2019-02-155-23/+26
| | | | | | | | | | | | | It never really encoded a invariant. * The linear register allocator just did partial pattern matches * The graph allocator just set it to (Just mapEmpty) for Nothing So I changed LiveInfo to directly contain the map. Further natCmmTopToLive which filled in Nothing is no longer exported. Instead we know call cmmTopLiveness which changes the type AND fills in the map.
* Allow resizing the stack for the graph allocator.klebinger.andreas@gmx.at2019-02-083-33/+70
| | | | | | | | | | The graph allocator now dynamically resizes the number of stack slots when running into the limit. This fixes #8657. Also loop membership of basic blocks is now available in the register allocator for cost heuristics.
* Fix unused-import warningsDavid Eichmann2018-11-225-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a fairly long-standing bug (dating back to 2015) in RdrName.bestImport, namely commit 9376249b6b78610db055a10d05f6592d6bbbea2f Author: Simon Peyton Jones <simonpj@microsoft.com> Date: Wed Oct 28 17:16:55 2015 +0000 Fix unused-import stuff in a better way In that patch got the sense of the comparison back to front, and thereby failed to implement the unused-import rules described in Note [Choosing the best import declaration] in RdrName This led to Trac #13064 and #15393 Fixing this bug revealed a bunch of unused imports in libraries; the ones in the GHC repo are part of this commit. The two important changes are * Fix the bug in bestImport * Modified the rules by adding (a) in Note [Choosing the best import declaration] in RdrName Reason: the previosu rules made Trac #5211 go bad again. And the new rule (a) makes sense to me. In unravalling this I also ended up doing a few other things * Refactor RnNames.ImportDeclUsage to use a [GlobalRdrElt] for the things that are used, rather than [AvailInfo]. This is simpler and more direct. * Rename greParentName to greParent_maybe, to follow GHC naming conventions * Delete dead code RdrName.greUsedRdrName Bumps a few submodules. Reviewers: hvr, goldfire, bgamari, simonmar, jrtc27 Subscribers: rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5312
* NCG: New code layout algorithm.Andreas Klebinger2018-11-175-41/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch implements a new code layout algorithm. It has been tested for x86 and is disabled on other platforms. Performance varies slightly be CPU/Machine but in general seems to be better by around 2%. Nofib shows only small differences of about +/- ~0.5% overall depending on flags/machine performance in other benchmarks improved significantly. Other benchmarks includes at least the benchmarks of: aeson, vector, megaparsec, attoparsec, containers, text and xeno. While the magnitude of gains differed three different CPUs where tested with all getting faster although to differing degrees. I tested: Sandy Bridge(Xeon), Haswell, Skylake * Library benchmark results summarized: * containers: ~1.5% faster * aeson: ~2% faster * megaparsec: ~2-5% faster * xml library benchmarks: 0.2%-1.1% faster * vector-benchmarks: 1-4% faster * text: 5.5% faster On average GHC compile times go down, as GHC compiled with the new layout is faster than the overhead introduced by using the new layout algorithm, Things this patch does: * Move code responsilbe for block layout in it's own module. * Move the NcgImpl Class into the NCGMonad module. * Extract a control flow graph from the input cmm. * Update this cfg to keep it in sync with changes during asm codegen. This has been tested on x64 but should work on x86. Other platforms still use the old codelayout. * Assign weights to the edges in the CFG based on type and limited static analysis which are then used for block layout. * Once we have the final code layout eliminate some redundant jumps. In particular turn a sequences of: jne .foo jmp .bar foo: into je bar foo: .. Test Plan: ci Reviewers: bgamari, jmct, jrtc27, simonmar, simonpj, RyanGlScott Reviewed By: RyanGlScott Subscribers: RyanGlScott, trommler, jmct, carter, thomie, rwbarton GHC Trac Issues: #15124 Differential Revision: https://phabricator.haskell.org/D4726
* Replace most occurences of foldl with foldl'.klebinger.andreas@gmx.at2018-08-214-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds foldl' to GhcPrelude and changes must occurences of foldl to foldl'. This leads to better performance especially for quick builds where GHC does not perform strictness analysis. It does change strictness behaviour when we use foldl' to turn a argument list into function applications. But this is only a drawback if code looks ONLY at the last argument but not at the first. And as the benchmarks show leads to fewer allocations in practice at O2. Compiler performance for Nofib: O2 Allocations: -1 s.d. ----- -0.0% +1 s.d. ----- -0.0% Average ----- -0.0% O2 Compile Time: -1 s.d. ----- -2.8% +1 s.d. ----- +1.3% Average ----- -0.8% O0 Allocations: -1 s.d. ----- -0.2% +1 s.d. ----- -0.1% Average ----- -0.2% Test Plan: ci Reviewers: goldfire, bgamari, simonmar, tdammers, monoidal Reviewed By: bgamari, monoidal Subscribers: tdammers, rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4929
* stack: fix stack allocations on WindowsTamar Christina2018-07-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: On Windows one is not allowed to drop the stack by more than a page size. The reason for this is that the OS only allocates enough stack till what the TEB specifies. After that a guard page is placed and the rest of the virtual address space is unmapped. The intention is that doing stack allocations will cause you to hit the guard which will then map the next page in and move the guard. This is done to prevent what in the Linux world is known as stack clash vulnerabilities https://access.redhat.com/security/cve/cve-2017-1000364. There are modules in GHC for which the liveliness analysis thinks the reserved 8KB of spill slots isn't enough. One being DynFlags and the other being Cabal. Though I think the Cabal one is likely a bug: ``` 4d6544: 81 ec 00 46 00 00 sub $0x4600,%esp 4d654a: 8d 85 94 fe ff ff lea -0x16c(%ebp),%eax 4d6550: 3b 83 1c 03 00 00 cmp 0x31c(%ebx),%eax 4d6556: 0f 82 de 8d 02 00 jb 4ff33a <_cLpg_info+0x7a> 4d655c: c7 45 fc 14 3d 50 00 movl $0x503d14,-0x4(%ebp) 4d6563: 8b 75 0c mov 0xc(%ebp),%esi 4d6566: 83 c5 fc add $0xfffffffc,%ebp 4d6569: 66 f7 c6 03 00 test $0x3,%si 4d656e: 0f 85 a6 d7 02 00 jne 503d1a <_cLpb_info+0x6> 4d6574: 81 c4 00 46 00 00 add $0x4600,%esp ``` It allocates nearly 18KB of spill slots for a simple 4 line function and doesn't even use it. Note that this doesn't happen on x64 or when making a validate build. Only when making a build without a validate and build.mk. This and the allocation in DynFlags means the stack allocation will jump over the guard page into unmapped memory areas and GHC or an end program segfaults. The pagesize on x86 Windows is 4KB which means we hit it very easily for these two modules, which explains the total DOA of GHC 32bit for the past 3 releases and the "random" segfaults on Windows. ``` 0:000> bp 00503d29 0:000> gn Breakpoint 0 hit WARNING: Stack overflow detected. The unwound frames are extracted from outside normal stack bounds. eax=03b6b9c9 ebx=00dc90f0 ecx=03cac48c edx=03cac43d esi=03b6b9c9 edi=03abef40 eip=00503d29 esp=013e96fc ebp=03cf8f70 iopl=0 nv up ei pl nz na po nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00000202 setup+0x103d29: 00503d29 89442440 mov dword ptr [esp+40h],eax ss:002b:013e973c=???????? WARNING: Stack overflow detected. The unwound frames are extracted from outside normal stack bounds. WARNING: Stack overflow detected. The unwound frames are extracted from outside normal stack bounds. 0:000> !teb TEB at 00384000 ExceptionList: 013effcc StackBase: 013f0000 StackLimit: 013eb000 ``` This doesn't fix the liveliness analysis but does fix the allocations, by emitting a function call to `__chkstk_ms` when doing allocations of larger than a page, this will make sure the stack is probed every page so the kernel maps in the next page. `__chkstk_ms` is provided by `libGCC`, which is under the `GNU runtime exclusion license`, so it's safe to link against it, even for proprietary code. (Technically we already do since we link compiled C code in.) For allocations smaller than a page we drop the stack and probe the new address. This avoids the function call and still makes sure we hit the guard if needed. PS: In case anyone is Wondering why we didn't notice this before, it's because we only test x86_64 and on Windows 10. On x86_64 the page size is 8KB and also the kernel is a bit more lenient on Windows 10 in that it seems to catch the segfault and resize the stack if it was unmapped: ``` 0:000> t eax=03b6b9c9 ebx=00dc90f0 ecx=03cac48c edx=03cac43d esi=03b6b9c9 edi=03abef40 eip=00503d2d esp=013e96fc ebp=03cf8f70 iopl=0 nv up ei pl nz na po nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00000202 setup+0x103d2d: 00503d2d 8b461b mov eax,dword ptr [esi+1Bh] ds:002b:03b6b9e4=03cac431 0:000> !teb TEB at 00384000 ExceptionList: 013effcc StackBase: 013f0000 StackLimit: 013e9000 ``` Likely Windows 10 has a guard page larger than previous versions. This fixes the stack allocations, and as soon as I get the time I will look at the liveliness analysis. I find it highly unlikely that simple Cabal function requires ~2200 spill slots. Test Plan: ./validate Reviewers: simonmar, bgamari Reviewed By: bgamari Subscribers: AndreasK, rwbarton, thomie, carter GHC Trac Issues: #15154 Differential Revision: https://phabricator.haskell.org/D4917
* Typofixes in comments and whitespace only [ci skip]Gabor Greif2018-06-261-6/+6
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* Track type variable scope more carefully.Richard Eisenberg2018-03-311-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main job of this commit is to track more accurately the scope of tyvars introduced by user-written foralls. For example, it would be to have something like this: forall a. Int -> (forall k (b :: k). Proxy '[a, b]) -> Bool In that type, a's kind must be k, but k isn't in scope. We had a terrible way of doing this before (not worth repeating or describing here, but see the old tcImplicitTKBndrs and friends), but now we have a principled approach: make an Implication when kind-checking a forall. Doing so then hooks into the existing machinery for preventing skolem-escape, performing floating, etc. This also means that we bump the TcLevel whenever going into a forall. The new behavior is done in TcHsType.scopeTyVars, but see also TcHsType.tc{Im,Ex}plicitTKBndrs, which have undergone significant rewriting. There are several Notes near there to guide you. Of particular interest there is that Implication constraints can now have skolems that are out of order; this situation is reported in TcErrors. A major consequence of this is a slightly tweaked process for type- checking type declarations. The new Note [Use SigTvs in kind-checking pass] in TcTyClsDecls lays it out. The error message for dependent/should_fail/TypeSkolEscape has become noticeably worse. However, this is because the code in TcErrors goes to some length to preserve pre-8.0 error messages for kind errors. It's time to rip off that plaster and get rid of much of the kind-error-specific error messages. I tried this, and doing so led to a lovely error message for TypeSkolEscape. So: I'm accepting the error message quality regression for now, but will open up a new ticket to fix it, along with a larger error-message improvement I've been pondering. This applies also to dependent/should_fail/{BadTelescope2,T14066,T14066e}, polykinds/T11142. Other minor changes: - isUnliftedTypeKind didn't look for tuples and sums. It does now. - check_type used check_arg_type on both sides of an AppTy. But the left side of an AppTy isn't an arg, and this was causing a bad error message. I've changed it to use check_type on the left-hand side. - Some refactoring around when we print (TYPE blah) in error messages. The changes decrease the times when we do so, to good effect. Of course, this is still all controlled by -fprint-explicit-runtime-reps Fixes #14066 #14749 Test cases: dependent/should_compile/{T14066a,T14749}, dependent/should_fail/T14066{,c,d,e,f,g,h}
* Hoopl.Collections: change right folds to strict left foldsMichal Terepeta2018-02-021-5/+4
| | | | | | | | | | | | | | | | | | | | | | It seems that most uses of these folds should be strict left folds (I could only find a single place that benefits from a right fold). So this removes the existing `setFold`/`mapFold`/`mapFoldWihKey` replaces them with: - `setFoldl`/`mapFoldl`/`mapFoldlWithKey` (strict left folds) - `setFoldr`/`mapFoldr` (for the less common case where a right fold actually makes sense, e.g., `CmmProcPoint`) Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: ./validate Reviewers: bgamari, simonmar Reviewed By: bgamari Subscribers: rwbarton, thomie, carter, kavon Differential Revision: https://phabricator.haskell.org/D4356
* Typofix in panicGabor Greif2017-10-301-1/+1
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* Performance improvements linear regAlloc (#7258)Tobias Dammers2017-10-251-11/+13
| | | | | | | | | | | | | | | | | | | | | | | When allocating and potentially spilling registers, we need to check the desired allocations against current allocations to decide where we can spill to, cq. which allocations we can toss and if so, how. Previously, this was done by walking the Cartesian product of the current allocations (`assig`) and the allocations to keep (`keep`), which has quadratic complexity. This patch introduces two improvements: 1. pre-filter the `assig` list, because we are only interested in two types of allocations (in register, and in register+memory), which will only make up a small and constant portion of the list; and 2. use set / map operations instead of lists, which reduces algorithmic complexity. Reviewers: austin, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie Differential Revision: https://phabricator.haskell.org/D4109
* compiler: introduce custom "GhcPrelude" PreludeHerbert Valerio Riedel2017-09-1921-0/+42
| | | | | | | | | | | | | | | | | | This switches the compiler/ component to get compiled with -XNoImplicitPrelude and a `import GhcPrelude` is inserted in all modules. This is motivated by the upcoming "Prelude" re-export of `Semigroup((<>))` which would cause lots of name clashes in every modulewhich imports also `Outputable` Reviewers: austin, goldfire, bgamari, alanz, simonmar Reviewed By: bgamari Subscribers: goldfire, rwbarton, thomie, mpickering, bgamari Differential Revision: https://phabricator.haskell.org/D3989
* Clean up opt and llcMoritz Angermann2017-09-061-1/+1
| | | | | | | | | | | | | | | | | | | | | The LLVM backend shells out to LLVMs `opt` and `llc` tools. This clean up introduces a shared data structure to carry the arguments we pass to each tool so that corresponding flags are next to each other. It drops the hard coded data layouts in favor of using `-mtriple` and have LLVM infer them. Furthermore we add `clang` as a proper tool, so we don't rely on assuming that `clang` is called `clang` on the `PATH` when using `clang` as the assembler. Finally this diff also changes the type of `optLevel` from `Int` to `Word`, as we do not have negative optimization levels. Reviewers: erikd, hvr, austin, rwbarton, bgamari, kavon Reviewed By: kavon Subscribers: michalt, Ericson2314, ryantrinkle, dfeuer, carter, simonpj, kavon, simonmar, thomie, erikd, snowleopard Differential Revision: https://phabricator.haskell.org/D3352
* nativeGen: Don't index into linked listsBen Gamari2017-08-291-6/+19
| | | | | | | | | | | There were a couple places where we indexed into linked lists of register names. Replace these with arrays. Reviewers: austin Subscribers: rwbarton, thomie Differential Revision: https://phabricator.haskell.org/D3893
* A bunch of typofixesGabor Greif2017-07-311-1/+1
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* Fix note references and some typosGabor Greif2017-07-261-1/+1
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* Hoopl: remove dependency on Hoopl packageMichal Terepeta2017-06-236-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This copies the subset of Hoopl's functionality needed by GHC to `cmm/Hoopl` and removes the dependency on the Hoopl package. The main motivation for this change is the confusing/noisy interface between GHC and Hoopl: - Hoopl has `Label` which is GHC's `BlockId` but different than GHC's `CLabel` - Hoopl has `Unique` which is different than GHC's `Unique` - Hoopl has `Unique{Map,Set}` which are different than GHC's `Uniq{FM,Set}` - GHC has its own specialized copy of `Dataflow`, so `cmm/Hoopl` is needed just to filter the exposed functions (filter out some of the Hoopl's and add the GHC ones) With this change, we'll be able to simplify this significantly. It'll also be much easier to do invasive changes (Hoopl is a public package on Hackage with users that depend on the current behavior) This should introduce no changes in functionality - it merely copies the relevant code. Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: ./validate Reviewers: austin, bgamari, simonmar Reviewed By: bgamari, simonmar Subscribers: simonpj, kavon, rwbarton, thomie Differential Revision: https://phabricator.haskell.org/D3616
* Typos in comments [ci skip]Gabor Greif2017-04-051-1/+1
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* Replace Digraph's Node type synonym with a data typeMatthew Pickering2017-04-042-20/+20
| | | | | | | | | | | | | This refactoring makes it more obvious when we are constructing a Node for the digraph rather than a less useful 3-tuple. Reviewers: austin, goldfire, bgamari, simonmar, dfeuer Reviewed By: dfeuer Subscribers: rwbarton, thomie Differential Revision: https://phabricator.haskell.org/D3414
* Typos in comments (notes too) [ci skip]Gabor Greif2017-03-241-1/+1
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* Typos in manual and commentsGabor Greif2017-03-141-2/+2
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* Upgrade UniqSet to a newtypeDavid Feuer2017-03-018-38/+42
| | | | | | | | | | | | | | | | | | | | | The fundamental problem with `type UniqSet = UniqFM` is that `UniqSet` has a key invariant `UniqFM` does not. For example, `fmap` over `UniqSet` will generally produce nonsense. * Upgrade `UniqSet` from a type synonym to a newtype. * Remove unused and shady `extendVarSet_C` and `addOneToUniqSet_C`. * Use cached unique in `tyConsOfType` by replacing `unitNameEnv (tyConName tc) tc` with `unitUniqSet tc`. Reviewers: austin, hvr, goldfire, simonmar, niteria, bgamari Reviewed By: niteria Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D3146
* nativeGen: Use `foldl'` instead of `foldr` in free register accumulationBen Gamari2017-01-246-9/+13
| | | | | | | | | | | | | | | | | | | Manipulations of `FreeRegs` values are all just bit-operations on a word. Turning these `foldr`s into `foldl'`s has a very small but consistent effect on compiler allocations, ``` -1 s.d. ----- -0.065% +1 s.d. ----- -0.018% Average ----- -0.042% ``` Test Plan: Validate Reviewers: austin Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2966
* Typofixes in manual and comments [ci skip]Gabor Greif2017-01-041-1/+1
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* NCG: Implement trivColorable for PowerPC 64-bitPeter Trommler2016-12-091-4/+4
| | | | | | | | | | | | | | | Define constants for 64-bit PowerPC in graph coloring register allocator. Test Plan: ./validate Reviewers: simonmar, austin, erikd, bgamari, hvr Reviewed By: bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2791
* BlockId: remove BlockMap and BlockSet synonymsMichal Terepeta2016-12-086-4/+9
| | | | | | | | | | | | | | | | | | | | This continues removal of `BlockId` module in favor of Hoopl's `Label`. Most of the changes here are mechanical, apart from the orphan `Outputable` instances for `LabelMap` and `LabelSet`. For now I've moved them to `cmm/Hoopl`, since it's already trying to manage all imports from Hoopl (to avoid any collisions). Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: validate Reviewers: bgamari, austin, simonmar Reviewed By: simonmar Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2800
* Remove most functions from cmm/BlockIdMichal Terepeta2016-11-294-10/+10
| | | | | | | | | | | | | | | | | | | | It seems that `BlockId` module could simply go away in favor of Hoopl's `Label`. This is the first step to do that. In a few places I had to add some type signatures, but most of them seem to help with code readability. Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: ./validate Reviewers: austin, simonmar, bgamari Reviewed By: bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2765
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