1. 01 Oct, 2020 1 commit
  2. 24 Sep, 2020 1 commit
    • Sylvain Henry's avatar
      Refactor CLabel pretty-printing · 667d6355
      Sylvain Henry authored
      * Don't depend on the selected backend to know if we print Asm or C
        labels: we already have PprStyle to determine this. Moreover even when
        a native backend is used (NCG, LLVM) we may want to C headers
        containing pretty-printed labels, so it wasn't a good predicate
        anyway.
      
      * Make pretty-printing code clearer and avoid partiality
      667d6355
  3. 18 Sep, 2020 2 commits
    • Sylvain Henry's avatar
      Generalize OutputableP · e45c8544
      Sylvain Henry authored
      Add a type parameter for the environment required by OutputableP. It
      avoids tying Platform with OutputableP.
      e45c8544
    • Sylvain Henry's avatar
      Introduce OutputableP · ca48076a
      Sylvain Henry authored
      Some types need a Platform value to be pretty-printed: CLabel, Cmm
      types, instructions, etc.
      
      Before this patch they had an Outputable instance and the Platform value
      was obtained via sdocWithDynFlags. It meant that the *renderer* of the
      SDoc was responsible of passing the appropriate Platform value (e.g. via
      the DynFlags given to showSDoc).  It put the burden of passing the
      Platform value on the renderer while the generator of the SDoc knows the
      Platform it is generating the SDoc for and there is no point passing a
      different Platform at rendering time.
      
      With this patch, we introduce a new OutputableP class:
      
         class OutputableP a where
            pdoc :: Platform -> a -> SDoc
      
      With this class we still have some polymorphism as we have with `ppr`
      (i.e. we can use `pdoc` on a variety of types instead of having a
      dedicated `pprXXX` function for each XXX type).
      
      One step closer removing `sdocWithDynFlags` (#10143) and supporting
      several platforms (#14335).
      ca48076a
  4. 04 Sep, 2020 1 commit
  5. 01 Sep, 2020 1 commit
    • Sylvain Henry's avatar
      Remove "Ord FastString" instance · 4b4fbc58
      Sylvain Henry authored
      FastStrings can be compared in 2 ways: by Unique or lexically. We don't
      want to bless one particular way with an "Ord" instance because it leads
      to bugs (#18562) or to suboptimal code (e.g. using lexical comparison
      while a Unique comparison would suffice).
      
      UTF-8 encoding has the advantage that sorting strings by their encoded
      bytes also sorts them by their Unicode code points, without having to
      decode the actual code points. BUT GHC uses Modified UTF-8 which
      diverges from UTF-8 by encoding \0 as 0xC080 instead of 0x00 (to avoid
      null bytes in the middle of a String so that the string can still be
      null-terminated). This patch adds a new `utf8CompareShortByteString`
      function that performs sorting by bytes but that also takes Modified
      UTF-8 into account. It is much more performant than decoding the strings
      into [Char] to perform comparisons (which we did in the previous patch).
      
      Bump haddock submodule
      4b4fbc58
  6. 12 Aug, 2020 1 commit
    • Sylvain Henry's avatar
      DynFlags: disentangle Outputable · accbc242
      Sylvain Henry authored
      - put panic related functions into GHC.Utils.Panic
      - put trace related functions using DynFlags in GHC.Driver.Ppr
      
      One step closer making Outputable fully independent of DynFlags.
      
      Bump haddock submodule
      accbc242
  7. 31 Jul, 2020 1 commit
    • Sylvain Henry's avatar
      Refactor CLabel pretty-printing · 56a7c193
      Sylvain Henry authored
      Pretty-printing CLabel relies on sdocWithDynFlags that we want to remove
      (#10143, #17957). It uses it to query the backend and the platform.
      
      This patch exposes Clabel ppr functions specialised for each backend so
      that backend code can directly use them.
      56a7c193
  8. 25 Jul, 2020 1 commit
    • Sylvain Henry's avatar
      Remove platform constant wrappers · 9dfeca6c
      Sylvain Henry authored
      Platform constant wrappers took a DynFlags parameter, hence implicitly
      used the target platform constants. We removed them to allow support
      for several platforms at once (#14335) and to avoid having to pass
      the full DynFlags to every function (#17957).
      
      Metric Decrease:
         T4801
      9dfeca6c
  9. 23 Jul, 2020 2 commits
    • Sylvain Henry's avatar
      Replace HscTarget with Backend · f7cc4313
      Sylvain Henry authored
      They both have the same role and Backend name is more explicit.
      
      Metric Decrease:
          T3064
      
      Update Haddock submodule
      f7cc4313
    • Sylvain Henry's avatar
      Replace ghcWithNativeCodeGen with a proper Backend datatype · 735f9d6b
      Sylvain Henry authored
      * Represent backends with a `Backend` datatype in GHC.Driver.Backend
      
      * Don't detect the default backend to use for the target platform at
        compile time in Hadrian/make but at runtime. It makes "Settings"
        simpler and it is a step toward making GHC multi-target.
      
      * The latter change also fixes hadrian which has not been updated to
        take into account that the NCG now supports AIX and PPC64 (cf
        df26b955 and
        d3c1dda6)
      
      * Also we don't treat iOS specifically anymore (cf
        cb4878ff)
      735f9d6b
  10. 25 Jun, 2020 1 commit
    • Takenobu Tani's avatar
      Clean up haddock hyperlinks of GHC.* (part1) · c7dd6da7
      Takenobu Tani authored
      This updates haddock comments only.
      
      This patch focuses to update for hyperlinks in GHC API's haddock comments,
      because broken links especially discourage newcomers.
      
      This includes the following hierarchies:
        - GHC.Hs.*
        - GHC.Core.*
        - GHC.Stg.*
        - GHC.Cmm.*
        - GHC.Types.*
        - GHC.Data.*
        - GHC.Builtin.*
        - GHC.Parser.*
        - GHC.Driver.*
        - GHC top
      c7dd6da7
  11. 24 Jun, 2020 1 commit
    • Sylvain Henry's avatar
      CmmToC: don't add extern decl to parsed Cmm data · 2636794d
      Sylvain Henry authored
      Previously, if a .cmm file *not in the RTS* contained something like:
      
      ```cmm
      section "rodata" { msg : bits8[] "Test\n"; }
      ```
      
      It would get compiled by CmmToC into:
      
      ```c
      ERW_(msg);
      const char msg[] = "Test\012";
      ```
      
      and fail with:
      
      ```
      /tmp/ghc32129_0/ghc_4.hc:5:12: error:
           error: conflicting types for \u2018msg\u2019
           const char msg[] = "Test\012";
                      ^~~
      
      In file included from /tmp/ghc32129_0/ghc_4.hc:3:0: error:
      
      /tmp/ghc32129_0/ghc_4.hc:4:6: error:
           note: previous declaration of \u2018msg\u2019 was here
           ERW_(msg);
                ^
      
      /builds/hsyl20/ghc/_build/install/lib/ghc-8.11.0.20200605/lib/../lib/x86_64-linux-ghc-8.11.0.20200605/rts-1.0/include/Stg.h:253:46: error:
           note: in definition of macro \u2018ERW_\u2019
           #define ERW_(X)   extern       StgWordArray (X)
                                                        ^
      ```
      
      See the rationale for this on https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/compiler/backends/ppr-c#prototypes
      
      Now we don't generate these extern declarations (ERW_, etc.) for
      top-level data. It shouldn't change anything for the RTS (the only place
      we use .cmm files) as it is already special cased in
      `GHC.Cmm.CLabel.needsCDecl`. And hand-written Cmm can use explicit
      extern declarations when needed.
      
      Note that it allows `cgrun069` test to pass with CmmToC (cf #15467).
      2636794d
  12. 17 Jun, 2020 1 commit
  13. 13 Jun, 2020 2 commits
    • Sylvain Henry's avatar
      Enhance UnitId use · e7272d53
      Sylvain Henry authored
      * use UnitId instead of String to identify wired-in units
      * use UnitId instead of Unit in the backend (Unit are only use by
        Backpack to produce type-checked interfaces, not real code)
      * rename lookup functions for consistency
      * documentation
      e7272d53
    • Sylvain Henry's avatar
      DynFlags refactoring VIII (#17957) · 2517a51c
      Sylvain Henry authored
      * Remove several uses of `sdocWithDynFlags`, especially in GHC.Llvm.*
      
      * Add LlvmOpts datatype to store Llvm backend options
      
      * Remove Outputable instances (for LlvmVar, LlvmLit, LlvmStatic and
        Llvm.MetaExpr) which require LlvmOpts.
      
      * Rename ppMetaExpr into ppMetaAnnotExpr (pprMetaExpr is now used in place of `ppr :: MetaExpr -> SDoc`)
      2517a51c
  14. 21 May, 2020 1 commit
  15. 06 May, 2020 1 commit
  16. 30 Apr, 2020 2 commits
    • Sylvain Henry's avatar
      Unit: split and rename modules · 8bfb0219
      Sylvain Henry authored
      Introduce GHC.Unit.* hierarchy for everything concerning units, packages
      and modules.
      
      Update Haddock submodule
      8bfb0219
    • Sylvain Henry's avatar
      Refactoring unit management code · 10d15f1e
      Sylvain Henry authored
      Over the years the unit management code has been modified a lot to keep
      up with changes in Cabal (e.g. support for several library components in
      the same package), to integrate BackPack, etc. I found it very hard to
      understand as the terminology wasn't consistent, was referring to past
      concepts, etc.
      
      The terminology is now explained as clearly as I could in the Note
      "About Units" and the code is refactored to reflect it.
      
      -------------------
      
      Many names were misleading: UnitId is not an Id but could be a virtual
      unit (an indefinite one instantiated on the fly), IndefUnitId
      constructor may contain a definite instantiated unit, etc.
      
         * Rename IndefUnitId into InstantiatedUnit
         * Rename IndefModule into InstantiatedModule
         * Rename UnitId type into Unit
         * Rename IndefiniteUnitId constructor into VirtUnit
         * Rename DefiniteUnitId constructor into RealUnit
         * Rename packageConfigId into mkUnit
         * Rename getPackageDetails into unsafeGetUnitInfo
         * Rename InstalledUnitId into UnitId
      
      Remove references to misleading ComponentId: a ComponentId is just an
      indefinite unit-id to be instantiated.
      
         * Rename ComponentId into IndefUnitId
         * Rename ComponentDetails into UnitPprInfo
         * Fix display of UnitPprInfo with empty version: this is now used for
           units dynamically generated by BackPack
      
      Generalize several types (Module, Unit, etc.) so that they can be used
      with different unit identifier types: UnitKey, UnitId, Unit, etc.
      
         * GenModule: Module, InstantiatedModule and InstalledModule are now
           instances of this type
         * Generalize DefUnitId, IndefUnitId, Unit, InstantiatedUnit,
           PackageDatabase
      
      Replace BackPack fake "hole" UnitId by a proper HoleUnit constructor.
      
      Add basic support for UnitKey. They should be used more in the future to
      avoid mixing them up with UnitId as we do now.
      
      Add many comments.
      
      Update Haddock submodule
      10d15f1e
  17. 26 Apr, 2020 1 commit
  18. 21 Apr, 2020 2 commits
    • Sylvain Henry's avatar
      CmmToAsm DynFlags refactoring (#17957) · 747093b7
      Sylvain Henry authored
      * Remove `DynFlags` parameter from `isDynLinkName`: `isDynLinkName` used
        to test the global `ExternalDynamicRefs` flag. Now we test it outside of
        `isDynLinkName`
      
      * Add new fields into `NCGConfig`: current unit id, sse/bmi versions,
        externalDynamicRefs, etc.
      
      * Replace many uses of `DynFlags` by `NCGConfig`
      
      * Moved `BMI/SSE` datatypes into `GHC.Platform`
      747093b7
    • Sylvain Henry's avatar
      Avoid `sdocWithDynFlags` in `pprCLbl` (#17957) · f2a98996
      Sylvain Henry authored
      * add a `DynFlags` parameter to `pprCLbl`
      * put `maybe_underscore` and `pprAsmCLbl` in a `where` clause to avoid
        `DynFlags` parameters
      f2a98996
  19. 18 Apr, 2020 1 commit
    • Sylvain Henry's avatar
      Modules (#13009) · 15312bbb
      Sylvain Henry authored
      * SysTools
      * Parser
      * GHC.Builtin
      * GHC.Iface.Recomp
      * Settings
      
      Update Haddock submodule
      
      Metric Decrease:
          Naperian
          parsing001
      15312bbb
  20. 06 Apr, 2020 1 commit
    • Ömer Sinan Ağacan's avatar
      Don't override proc CafInfos in ticky builds · dcfe29c8
      Ömer Sinan Ağacan authored
      Fixes #17947
      
      When we have a ticky label for a proc, IdLabels for the ticky counter
      and proc entry share the same Name. This caused overriding proc CafInfos
      with the ticky CafInfos (i.e. NoCafRefs) during SRT analysis.
      
      We now ignore the ticky labels when building SRTMaps. This makes sense
      because:
      
      - When building the current module they don't need to be in SRTMaps as
        they're initialized as non-CAFFY (see mkRednCountsLabel), so they
        don't take part in the dependency analysis and they're never added to
        SRTs.
      
        (Reminder: a "dependency" in the SRT analysis is a CAFFY dependency,
        non-CAFFY uses are not considered as dependencies for the algorithm)
      
      - They don't appear in the interfaces as they're not exported, so it
        doesn't matter for cross-module concerns whether they're in the SRTMap
        or not.
      
      See also the new Note [Ticky labels in SRT analysis].
      dcfe29c8
  21. 29 Mar, 2020 1 commit
  22. 15 Mar, 2020 1 commit
    • Sylvain Henry's avatar
      Refactor CmmToAsm (disentangle DynFlags) · 2e82465f
      Sylvain Henry authored
      This patch disentangles a bit more DynFlags from the native code
      generator (CmmToAsm).
      
      In more details:
      
      - add a new NCGConfig datatype in GHC.CmmToAsm.Config which contains the
        configuration of a native code generation session
      - explicitly pass NCGConfig/Platform arguments when necessary
      - as a consequence `sdocWithPlatform` is gone and there are only a few
        `sdocWithDynFlags` left
      - remove the use of `unsafeGlobalDynFlags` from GHC.CmmToAsm.CFG
      - remove `sdocDebugLevel` (now we pass the debug level via NCGConfig)
      
      There are still some places where DynFlags is used, especially because
      of pretty-printing (CLabel), because of Cmm helpers (such as
      `cmmExprType`) and because of `Outputable` instance for the
      instructions. These are left for future refactoring as this patch is
      already big.
      2e82465f
  23. 13 Mar, 2020 1 commit
    • Sylvain Henry's avatar
      Rename isDllName · 44fad4a9
      Sylvain Henry authored
      I wanted to fix the dangling comment in `isDllName` ("This is the cause
      of #", #8696 is already mentioned earlier). I took the opportunity to
      change the function name to better reflect what it does.
      44fad4a9
  24. 26 Feb, 2020 1 commit
  25. 22 Feb, 2020 1 commit
  26. 31 Jan, 2020 2 commits
    • Andreas Klebinger's avatar
      A few optimizations in STG and Cmm parts: · 2a87a565
      Andreas Klebinger authored
      (Guided by the profiler output)
      
      - Add a few bang patterns, INLINABLE annotations, and a seqList in a few
        places in Cmm and STG parts.
      
      - Do not add external variables as dependencies in STG dependency
        analysis (GHC.Stg.DepAnal).
      2a87a565
    • Ömer Sinan Ağacan's avatar
      Do CafInfo/SRT analysis in Cmm · c846618a
      Ömer Sinan Ağacan authored
      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
      c846618a
  27. 25 Jan, 2020 1 commit
  28. 13 Jan, 2020 1 commit
  29. 28 Nov, 2019 1 commit
  30. 21 Oct, 2019 1 commit
    • Ben Gamari's avatar
      rts: Implement concurrent collection in the nonmoving collector · bd8e3ff4
      Ben Gamari authored
      
      
      This extends the non-moving collector to allow concurrent collection.
      
      The full design of the collector implemented here is described in detail
      in a technical note
      
          B. Gamari. "A Concurrent Garbage Collector For the Glasgow Haskell
          Compiler" (2018)
      
      This extension involves the introduction of a capability-local
      remembered set, known as the /update remembered set/, which tracks
      objects which may no longer be visible to the collector due to mutation.
      To maintain this remembered set we introduce a write barrier on
      mutations which is enabled while a concurrent mark is underway.
      
      The update remembered set representation is similar to that of the
      nonmoving mark queue, being a chunked array of `MarkEntry`s. Each
      `Capability` maintains a single accumulator chunk, which it flushed
      when it (a) is filled, or (b) when the nonmoving collector enters its
      post-mark synchronization phase.
      
      While the write barrier touches a significant amount of code it is
      conceptually straightforward: the mutator must ensure that the referee
      of any pointer it overwrites is added to the update remembered set.
      However, there are a few details:
      
       * In the case of objects with a dirty flag (e.g. `MVar`s) we can
         exploit the fact that only the *first* mutation requires a write
         barrier.
      
       * Weak references, as usual, complicate things. In particular, we must
         ensure that the referee of a weak object is marked if dereferenced by
         the mutator. For this we (unfortunately) must introduce a read
         barrier, as described in Note [Concurrent read barrier on deRefWeak#]
         (in `NonMovingMark.c`).
      
       * Stable names are also a bit tricky as described in Note [Sweeping
         stable names in the concurrent collector] (`NonMovingSweep.c`).
      
      We take quite some pains to ensure that the high thread count often seen
      in parallel Haskell applications doesn't affect pause times. To this end
      we allow thread stacks to be marked either by the thread itself (when it
      is executed or stack-underflows) or the concurrent mark thread (if the
      thread owning the stack is never scheduled). There is a non-trivial
      handshake to ensure that this happens without racing which is described
      in Note [StgStack dirtiness flags and concurrent marking].
      Co-Authored-by: Ömer Sinan Ağacan's avatarÖmer Sinan Ağacan <omer@well-typed.com>
      bd8e3ff4
  31. 25 Jun, 2019 1 commit
  32. 20 Jun, 2019 1 commit
    • John Ericson's avatar
      Move 'Platform' to ghc-boot · bff2f24b
      John Ericson authored
      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.
      bff2f24b
  33. 29 May, 2019 1 commit
    • John Ericson's avatar
      Inline `Settings` into `DynFlags` · bfccd832
      John Ericson authored
      After the previous commit, `Settings` is just a thin wrapper around
      other groups of settings. While `Settings` is used by GHC-the-executable
      to initalize `DynFlags`, in principle another consumer of
      GHC-the-library could initialize `DynFlags` a different way. It
      therefore doesn't make sense for `DynFlags` itself (library code) to
      separate the settings that typically come from `Settings` from the
      settings that typically don't.
      bfccd832
  34. 14 May, 2019 1 commit
    • John Ericson's avatar
      Remove all target-specific portions of Config.hs · e529c65e
      John Ericson authored
      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!
      e529c65e