Ben Gamari pushed to branch wip/backports-9.14 at Glasgow Haskell Compiler / GHC

Commits:

• 5194ccbc
  by Simon Peyton Jones at 2025-08-15T09:07:30-04:00

  Make injecting implicit bindings into its own pass
  
  Previously we were injecting "impliicit bindings" (data constructor
  worker and wrappers etc)
  
    - both at the end of CoreTidy,
    - and at the start of CorePrep
  
  This is unpleasant and confusing.  This patch puts it it its own pass,
  addImplicitBinds, which runs between the two.
  
  The function `GHC.CoreToStg.AddImplicitBinds.addImplicitBinds` now takes /all/
  TyCons, not just the ones for algebraic data types.  That change ripples
  through to
       - corePrepPgm
       - doCodeGen
       - byteCodeGen
  All take [TyCon] which includes all TyCons
  
  (cherry picked from commit fd811ded65bb9b19571ba525fb5eaf8f23a4533d)
  

• 779a7bc6
  by Simon Peyton Jones at 2025-08-15T09:07:33-04:00

  Implement unary classes
  
  The big change is described exhaustively in
  
     Note [Unary class magic] in GHC.Core.TyCon
  
  Other changes
  
  * We never unbox class dictionaries in worker/wrapper.  This has been true for some
    time now, but the logic is now centralised in functions in
    GHC.Core.Opt.WorkWrap.Utils, namely `canUnboxTyCon`, and `canUnboxArg`
    See Note [Do not unbox class dictionaries] in GHC.Core.Opt.WorkWrap.Utils.
  
  * Refactored the `notWorthFloating` logic in GHc.Core.Opt.SetLevels.
    I can't remember if I actually changed any behaviour here, but if so it's
    only in a corner cases.
  
  * Fixed a bug in `GHC.Core.TyCon.isEnumerationTyCon`, which was wrongly returning
    True for (##).
  
  * Remove redundant Role argument to `liftCoSubstWithEx`.  It was always
    Representational.
  
  * I refactored evidence generation in the constraint solver:
    * Made GHC.Tc.Types.Evidence contain better abstactions for evidence
      generation.
    * I deleted the file `GHC.Tc.Types.EvTerm` and merged its (small) contents
      elsewhere. It wasn't paying its way.
    * Made evidence for implicit parameters go via a proper abstraction.
  
  * Fix inlineBoringOk; see (IB6) in Note [inlineBoringOk]
    This fixes a slowdown in `countdownEffectfulDynLocal`
    in the `effectful` library.
  
  Smaller things
  
  * Rename `isDataTyCon` to `isBoxedDataTyCon`.
  * GHC.Core.Corecion.liftCoSubstWithEx was only called with Representational role,
    so I baked that into the function and removed the argument.
  * Get rid of `GHC.Core.TyCon.tyConSingleAlgDataCon_maybe` in favour of calling
    `not isNewTyCon` at the call sites; more explicit.
  * Refatored `GHC.Core.TyCon.isInjectiveTyCon`; but I don't think I changed its
    behaviour
  * Moved `decomposeIPPred` to GHC.Core.Predicate
  
  Compile time performance changes:
    geo. mean        +0.1%
      minimum        -6.8%
      maximum       +14.4%
  
  The +14% one is in T21839c, where it seems that a bit more inlining
  is taking place.  That seems acceptable; and the average change is small
  
  Metric Decrease:
      LargeRecord
      T12227
      T12707
      T16577
      T21839r
      T5642
  Metric Increase:
      T15164
      T21839c
      T3294
      T5321FD
      T5321Fun
      WWRec
  
  (cherry picked from commit 9bd7fcc518111a1549c98720c222cdbabd32ed46)
  

93 changed files:

• compiler/GHC/Builtin/Types.hs
• compiler/GHC/ByteCode/InfoTable.hs
• compiler/GHC/Core/Class.hs
• compiler/GHC/Core/Coercion.hs
• compiler/GHC/Core/DataCon.hs
• compiler/GHC/Core/FamInstEnv.hs
• compiler/GHC/Core/Opt/Arity.hs
• compiler/GHC/Core/Opt/CprAnal.hs
• compiler/GHC/Core/Opt/DmdAnal.hs
• compiler/GHC/Core/Opt/OccurAnal.hs
• compiler/GHC/Core/Opt/SetLevels.hs
• compiler/GHC/Core/Opt/Specialise.hs
• compiler/GHC/Core/Opt/WorkWrap/Utils.hs
• compiler/GHC/Core/Predicate.hs
• compiler/GHC/Core/TyCo/Rep.hs
• compiler/GHC/Core/TyCon.hs
• compiler/GHC/Core/Type.hs
• compiler/GHC/Core/Unfold.hs
• compiler/GHC/Core/Unfold/Make.hs
• compiler/GHC/Core/Utils.hs
• compiler/GHC/CoreToStg.hs
• + compiler/GHC/CoreToStg/AddImplicitBinds.hs
• compiler/GHC/CoreToStg/Prep.hs
• compiler/GHC/Driver/Main.hs
• compiler/GHC/HsToCore/Binds.hs
• compiler/GHC/HsToCore/Expr.hs
• compiler/GHC/HsToCore/Foreign/Call.hs
• compiler/GHC/Iface/Decl.hs
• compiler/GHC/Iface/Syntax.hs
• compiler/GHC/Iface/Tidy.hs
• compiler/GHC/IfaceToCore.hs
• compiler/GHC/Rename/Module.hs
• compiler/GHC/StgToByteCode.hs
• compiler/GHC/StgToCmm.hs
• compiler/GHC/Tc/Errors.hs
• compiler/GHC/Tc/Gen/Bind.hs
• compiler/GHC/Tc/Gen/Expr.hs
• compiler/GHC/Tc/Instance/Class.hs
• compiler/GHC/Tc/Instance/Family.hs
• compiler/GHC/Tc/Solver/Default.hs
• compiler/GHC/Tc/Solver/Dict.hs
• compiler/GHC/Tc/Solver/Equality.hs
• compiler/GHC/Tc/Solver/Monad.hs
• compiler/GHC/Tc/Solver/Solve.hs
• compiler/GHC/Tc/TyCl.hs
• compiler/GHC/Tc/TyCl/Build.hs
• compiler/GHC/Tc/TyCl/Instance.hs
• compiler/GHC/Tc/TyCl/PatSyn.hs
• compiler/GHC/Tc/TyCl/Utils.hs
• − compiler/GHC/Tc/Types/EvTerm.hs
• compiler/GHC/Tc/Types/Evidence.hs
• compiler/GHC/Tc/Utils/TcMType.hs
• compiler/GHC/Types/Demand.hs
• compiler/GHC/Types/Id.hs
• compiler/GHC/Types/Id/Make.hs
• compiler/GHC/Types/RepType.hs
• compiler/GHC/Types/TyThing.hs
• compiler/ghc.cabal.in
• testsuite/tests/core-to-stg/T24124.stderr
• testsuite/tests/deSugar/should_compile/T2431.stderr
• testsuite/tests/dmdanal/should_compile/T16029.stdout
• testsuite/tests/dmdanal/sigs/T21119.stderr
• testsuite/tests/dmdanal/sigs/T21888.stderr
• testsuite/tests/ghci.debugger/scripts/break011.stdout
• testsuite/tests/ghci.debugger/scripts/break024.stdout
• testsuite/tests/indexed-types/should_compile/T2238.hs
• testsuite/tests/numeric/should_compile/T15547.stderr
• testsuite/tests/numeric/should_compile/T23907.stderr
• testsuite/tests/roles/should_compile/Roles14.stderr
• testsuite/tests/roles/should_compile/Roles3.stderr
• testsuite/tests/roles/should_compile/Roles4.stderr
• testsuite/tests/simplCore/should_compile/DataToTagFamilyScrut.stderr
• testsuite/tests/simplCore/should_compile/T15205.stderr
• testsuite/tests/simplCore/should_compile/T17366.stderr
• testsuite/tests/simplCore/should_compile/T17966.stderr
• testsuite/tests/simplCore/should_compile/T22309.stderr
• testsuite/tests/simplCore/should_compile/T22375DataFamily.stderr
• testsuite/tests/simplCore/should_compile/T23307.stderr
• testsuite/tests/simplCore/should_compile/T23307a.stderr
• testsuite/tests/simplCore/should_compile/T25389.stderr
• testsuite/tests/simplCore/should_compile/T25713.stderr
• testsuite/tests/simplCore/should_compile/T7360.stderr
• testsuite/tests/simplStg/should_compile/T15226b.stderr
• testsuite/tests/tcplugins/CtIdPlugin.hs
• testsuite/tests/typecheck/should_compile/Makefile
• testsuite/tests/typecheck/should_compile/T12763.stderr
• testsuite/tests/typecheck/should_compile/T14774.stdout
• testsuite/tests/typecheck/should_compile/T18406b.stderr
• testsuite/tests/typecheck/should_compile/T18529.stderr
• testsuite/tests/typecheck/should_compile/all.T
• testsuite/tests/unboxedsums/unpack_sums_7.stdout
• testsuite/tests/wasm/should_run/control-flow/LoadCmmGroup.hs
• testsuite/tests/wasm/should_run/control-flow/RunWasm.hs

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