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* Modules: Llvm (#13009)Sylvain Henry2020-02-1812-5355/+0
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* Do CafInfo/SRT analysis in CmmÖmer Sinan Ağacan2020-01-314-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Ellis2020-01-272-0/+3
| | | | | | 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 Henry2020-01-256-21/+21
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* llvmGen: Fix #14251Ben Gamari2020-01-202-23/+115
| | | | | | | | | | | | | | Fixes the calling convention for functions passing raw SSE-register values by adding padding as needed to get the values in the right registers. This problem cropped up when some args were unused an dropped from the live list. This folds together 2e23e1c7de01c92b038e55ce53d11bf9db993dd4 and 73273be476a8cc6c13368660b042b3b0614fd928 previously from @kavon. Metric Increase: T12707 ManyConstructors
* llvmGen: Fix typo in readnone attributeBen Gamari2020-01-201-1/+1
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* llvmGen: Don't trash STG registersBen Gamari2020-01-201-38/+2
| | | | Fixes #13904.
* Fix more typos, via an improved Levenshtein-style correctorBrian Wignall2020-01-121-1/+1
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* Fix typos, via a Levenshtein-style correctorBrian Wignall2020-01-041-1/+1
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* llvmGen: Drop old fix for #11649Ben Gamari2019-12-301-36/+1
| | | | | This was a hack which is no longer necessary now since we introduce a dedicated entry block for each procedure.
* llvmGen: Ensure that entry labels don't have predecessorsBen Gamari2019-12-301-7/+14
| | | | | | | | | | The LLVM IR forbids the entry label of a procedure from having any predecessors. In the case of a simple looping function the LLVM code generator broke this invariant, as noted in #17589. Fix this by moving the function prologue to its own basic block, as suggested by @kavon in #11649. Fixes #11649 and #17589.
* Add GHC-API logging hooksSylvain Henry2019-12-182-5/+6
| | | | | | | | | | | | | | | | | | | | | | | * Add 'dumpAction' hook to DynFlags. It allows GHC API users to catch dumped intermediate codes and information. The format of the dump (Core, Stg, raw text, etc.) is now reported allowing easier automatic handling. * Add 'traceAction' hook to DynFlags. Some dumps go through the trace mechanism (for instance unfoldings that have been considered for inlining). This is problematic because: 1) dumps aren't written into files even with -ddump-to-file on 2) dumps are written on stdout even with GHC API 3) in this specific case, dumping depends on unsafe globally stored DynFlags which is bad for GHC API users We introduce 'traceAction' hook which allows GHC API to catch those traces and to avoid using globally stored DynFlags. * Avoid dumping empty logs via dumpAction/traceAction (but still write empty files to keep the existing behavior)
* Add `timesInt2#` primopSylvain Henry2019-12-021-0/+1
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* Fix endian handling of LLVM backendStefan Schulze Frielinghaus2019-11-281-10/+4
| | | | | Get rid of CPP macro WORDS_BIGENDIAN which is not defined anymore, and replace it by DynFlag. This fixes partially #17337.
* Optimize MonadUnique instances based on IO (#16843)nineonine2019-11-192-15/+11
| | | | | Metric Decrease: T14683
* For s390x issue a warning if LLVM 9 or older is usedStefan Schulze Frielinghaus2019-11-071-0/+6
| | | | | For s390x the GHC calling convention is only supported since LLVM version 10. Issue a warning in case an older version of LLVM is used.
* Make dynflag argument for withTiming pure.Andreas Klebinger2019-10-232-2/+2
| | | | | | | | | | | | 19 times out of 20 we already have dynflags in scope. We could just always use `return dflags`. But this is in fact not free. When looking at some STG code I noticed that we always allocate a closure for this expression in the heap. Clearly a waste in these cases. For the other cases we can either just modify the callsite to get dynflags or use the _D variants of withTiming I added which will use getDynFlags under the hood.
* Implement s390x LLVM backend.Stefan Schulze Frielinghaus2019-10-221-1/+3
| | | | | | 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.
* Refactor, document, and optimize LLVM configuration loadingBen Gamari2019-10-071-4/+10
| | | | | | | | | | | | As described in the new Note [LLVM Configuration] in SysTools, we now load llvm-targets and llvm-passes lazily to avoid the overhead of doing so when -fllvm isn't used (also known as "the common case"). Noticed in #17003. Metric Decrease: T12234 T12150
* Module hierarchy: StgToCmm (#13009)Sylvain Henry2019-09-103-3/+3
| | | | | | Add StgToCmm module hierarchy. Platform modules that are used in several other places (NCG, LLVM codegen, Cmm transformations) are put into GHC.Platform.
* Fix LLVM version check yet againÖmer Sinan Ağacan2019-08-292-29/+42
| | | | | | | | | | | | | | | There were two problems with LLVM version checking: - The parser would only parse x and x.y formatted versions. E.g. 1.2.3 would be rejected. - The version check was too strict and would reject x.y formatted versions. E.g. when we support version 7 it'd reject 7.0 ("LLVM version 7.0") and only accept 7 ("LLVM version 7"). We now parse versions with arbitrarily deep minor numbering (x.y.z.t...) and accept versions as long as the major version matches the supported version (e.g. 7.1, 7.1.2, 7.1.2.3 ...).
* Return results of Cmm streams in backendsÖmer Sinan Ağacan2019-08-282-8/+12
| | | | | | | | | | | | | | | | | | | 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]
* Make non-streaming LLVM and C backends streamingÖmer Sinan Ağacan2019-08-231-2/+1
| | | | | | | | | 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.
* Revert "Add support for SIMD operations in the NCG"Ben Gamari2019-07-163-29/+27
| | | | | | | Unfortunately this will require more work; register allocation is quite broken. This reverts commit acd795583625401c5554f8e04ec7efca18814011.
* Remove LLVM_TARGET platform macrosJohn Ericson2019-07-141-1/+1
| | | | | Instead following @angerman's suggestion put them in the config file. Maybe we could re-key llvm-targets someday, but this is good for now.
* Add support for SIMD operations in the NCGAbhiroop Sarkar2019-07-033-27/+29
| | | | | | | 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>
* Correct closure observation, construction, and mutation on weak memory machines.Travis Whitaker2019-06-281-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here the following changes are introduced: - A read barrier machine op is added to Cmm. - The order in which a closure's fields are read and written is changed. - Memory barriers are added to RTS code to ensure correctness on out-or-order machines with weak memory ordering. Cmm has a new CallishMachOp called MO_ReadBarrier. On weak memory machines, this is lowered to an instruction that ensures memory reads that occur after said instruction in program order are not performed before reads coming before said instruction in program order. On machines with strong memory ordering properties (e.g. X86, SPARC in TSO mode) no such instruction is necessary, so MO_ReadBarrier is simply erased. However, such an instruction is necessary on weakly ordered machines, e.g. ARM and PowerPC. Weam memory ordering has consequences for how closures are observed and mutated. For example, consider a closure that needs to be updated to an indirection. In order for the indirection to be safe for concurrent observers to enter, said observers must read the indirection's info table before they read the indirectee. Furthermore, the entering observer makes assumptions about the closure based on its info table contents, e.g. an INFO_TYPE of IND imples the closure has an indirectee pointer that is safe to follow. When a closure is updated with an indirection, both its info table and its indirectee must be written. With weak memory ordering, these two writes can be arbitrarily reordered, and perhaps even interleaved with other threads' reads and writes (in the absence of memory barrier instructions). Consider this example of a bad reordering: - An updater writes to a closure's info table (INFO_TYPE is now IND). - A concurrent observer branches upon reading the closure's INFO_TYPE as IND. - A concurrent observer reads the closure's indirectee and enters it. (!!!) - An updater writes the closure's indirectee. Here the update to the indirectee comes too late and the concurrent observer has jumped off into the abyss. Speculative execution can also cause us issues, consider: - An observer is about to case on a value in closure's info table. - The observer speculatively reads one or more of closure's fields. - An updater writes to closure's info table. - The observer takes a branch based on the new info table value, but with the old closure fields! - The updater writes to the closure's other fields, but its too late. Because of these effects, reads and writes to a closure's info table must be ordered carefully with respect to reads and writes to the closure's other fields, and memory barriers must be placed to ensure that reads and writes occur in program order. Specifically, updates to a closure must follow the following pattern: - Update the closure's (non-info table) fields. - Write barrier. - Update the closure's info table. Observing a closure's fields must follow the following pattern: - Read the closure's info pointer. - Read barrier. - Read the closure's (non-info table) fields. This patch updates RTS code to obey this pattern. This should fix long-standing SMP bugs on ARM (specifically newer aarch64 microarchitectures supporting out-of-order execution) and PowerPC. This fixes issue #15449. Co-Authored-By: Ben Gamari <ben@well-typed.com>
* Fixes for LLVM 7Erik de Castro Lopo2019-06-242-5/+16
| | | | | | | LLVM version numberinf changed recently. Previously, releases were numbered 4.0, 5.0 and 6.0 but with version 7, they dropped the redundant ".0". Fix requires for Llvm detection and some code.
* Move 'Platform' to ghc-bootJohn Ericson2019-06-194-4/+4
| | | | | | | 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 Gogolewski2019-06-121-4/+2
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* Introduce log1p and expm1 primopschessai2019-06-091-0/+4
| | | | | Previously log and exp were primitives yet log1p and expm1 were FFI calls. Fix this non-uniformity.
* Remove all target-specific portions of Config.hsJohn Ericson2019-05-141-6/+3
| | | | | | | | | | | | | | | | | | | 1. If GHC is to be multi-target, these cannot be baked in at compile time. 2. Compile-time flags have a higher maintenance than run-time flags. 3. The old way makes build system implementation (various bootstrapping details) with the thing being built. E.g. GHC doesn't need to care about which integer library *will* be used---this is purely a crutch so the build system doesn't need to pass flags later when using that library. 4. Experience with cross compilation in Nixpkgs has shown things work nicer when compiler's can *optionally* delegate the bootstrapping the package manager. The package manager knows the entire end-goal build plan, and thus can make top-down decisions on bootstrapping. GHC can just worry about GHC, not even core library like base and ghc-prim!
* asm-emit-time IND_STATIC eliminationGabor Greif2019-04-154-8/+61
| | | | | | | | | | | | When a new closure identifier is being established to a local or exported closure already emitted into the same module, refrain from adding an IND_STATIC closure, and instead emit an assembly-language alias. Inter-module IND_STATIC objects still remain, and need to be addressed by other measures. Binary-size savings on nofib are around 0.1%.
* removing x87 register support from native code genCarter Schonwald2019-04-101-1/+0
| | | | | | | | | | | | | | | | * 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.
* Add support for bitreverse primopAlexandre2019-04-011-4/+7
| | | | | | This commit includes the necessary changes in code and documentation to support a primop that reverses a word's bits. It also includes a test.
* Update Trac ticket URLs to point to GitLabRyan Scott2019-03-152-2/+2
| | | | | This moves all URL references to Trac tickets to their corresponding GitLab counterparts.
* Use ByteString to represent Cmm string literals (#16198)Sylvain Henry2019-01-311-1/+3
| | | | Also used ByteString in some other relevant places
* Prepare source-tree for base-4.13 MFP bumpHerbert Valerio Riedel2019-01-181-2/+2
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* llvmGen: Fix minor correctness issueGabor Greif2018-12-131-1/+1
| | | | | | The alias is of type i8, so its global variable name should have type i8*. Anyway we should never deal with pointers to (i8*)!
* Fix unused-import warningsDavid Eichmann2018-11-221-1/+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
* llvmGen: Eliminate duplicate definitionGabor Greif2018-11-222-3/+2
| | | | remove local
* Rename literal constructorsSylvain Henry2018-11-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | In a previous patch we replaced some built-in literal constructors (MachInt, MachWord, etc.) with a single LitNumber constructor. In this patch we replace the `Mach` prefix of the remaining constructors with `Lit` for consistency (e.g., LitChar, LitLabel, etc.). Sadly the name `LitString` was already taken for a kind of FastString and it would become misleading to have both `LitStr` (literal constructor renamed after `MachStr`) and `LitString` (FastString variant). Hence this patch renames the FastString variant `PtrString` (which is more accurate) and the literal string constructor now uses the least surprising `LitString` name. Both `Literal` and `LitString/PtrString` have recently seen breaking changes so doing this kind of renaming now shouldn't harm much. Reviewers: hvr, goldfire, bgamari, simonmar, jrtc27, tdammers Subscribers: tdammers, rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4881
* Minor performance optimisationGabor Greif2018-11-221-5/+5
| | | | only concat once
* another minor refactoringGabor Greif2018-11-221-4/+4
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* Revert "Multiple fixes / improvements for LLVM backend"Ben Gamari2018-11-073-65/+59
| | | | This reverts commit adcb5fb47c0942671d409b940d8884daa9359ca4.
* Revert "Fix for T14251 on ARM"Ben Gamari2018-11-072-90/+39
| | | | This reverts commit d8495549ba9d194815c2d0eaee6797fc7c00756a.
* [LlvmCodeGen] Fixes for Int8#/Word8#Michal Terepeta2018-11-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes two isssues: - Using bitcast for MO_XX_Conv Arguments to a bitcast must be of the same size. We should be using `trunc` and `zext` instead. - Using unsupported MO_*_QuotRem for LLVM The two primops `MO_*_QuotRem` are not supported by the LLVM backend, so we shouldn't use them for `Int8#`/`Word8#` (just as we do not use them for `Int#`/`Word#`). Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: manually run tests with WAY=llvm Reviewers: bgamari, simonmar Reviewed By: bgamari Subscribers: rwbarton, carter GHC Trac Issues: #15864 Differential Revision: https://phabricator.haskell.org/D5304
* Add Int8# and Word8#Michal Terepeta2018-11-021-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the first step of implementing: https://github.com/ghc-proposals/ghc-proposals/pull/74 The main highlights/changes: primops.txt.pp gets two new sections for two new primitive types for signed and unsigned 8-bit integers (Int8# and Word8 respectively) along with basic arithmetic and comparison operations. PrimRep/RuntimeRep get two new constructors for them. All of the primops translate into the existing MachOPs. For CmmCalls the codegen will now zero-extend the values at call site (so that they can be moved to the right register) and then truncate them back their original width. x86 native codegen needed some updates, since it wasn't able to deal with the new widths, but all the changes are quite localized. LLVM backend seems to just work. This is the second attempt at merging this, after the first attempt in D4475 had to be backed out due to regressions on i386. Bumps binary submodule. Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com> Test Plan: ./validate (on both x86-{32,64}) Reviewers: bgamari, hvr, goldfire, simonmar Subscribers: rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5258
* Fix for T14251 on ARMKavon Farvardin2018-10-282-39/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | We now calculate the SSE register padding needed to fix the calling convention in LLVM in a robust way: grouping them by whether registers in that class overlap (with the same class overlapping itself). My prior patch assumed that no matter the platform, physical register Fx aliases with Dx, etc, for our calling convention. This is unfortunately not the case for any platform except x86-64. Test Plan: Only know how to test on x86-64, but it should be tested on ARM with: `make test WAYS=llvm && make test WAYS=optllvm` Reviewers: bgamari, angerman Reviewed By: bgamari Subscribers: rwbarton, carter GHC Trac Issues: #15780, #14251, #15747 Differential Revision: https://phabricator.haskell.org/D5254
* Revert "Add Int8# and Word8#"Ben Gamari2018-10-091-4/+0
| | | | | | | | | This unfortunately broke i386 support since it introduced references to byte-sized registers that don't exist on that architecture. Reverts binary submodule This reverts commit 5d5307f943d7581d7013ffe20af22233273fba06.