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01d3154e
by Wen Kokke at 2025-07-10T17:06:36+01:00
Fix documentation for HEAP_PROF_SAMPLE_STRING
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ac259c48
by Wen Kokke at 2025-07-10T17:06:38+01:00
Fix documentation for HEAP_PROF_SAMPLE_COST_CENTRE
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2b4db9ba
by Pi Delport at 2025-07-11T16:40:52-04:00
(Applicative docs typo: missing "one")
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f707bab4
by Andreas Klebinger at 2025-07-12T14:56:16+01:00
Specialise: Improve specialisation by refactoring interestingDict
This MR addresses #26051, which concerns missed type-class specialisation.
The main payload of the MR is to completely refactor the key function
`interestingDict` in GHC.Core.Opt.Specialise
The main change is that we now also look at the structure of the
dictionary we consider specializing on, rather than only the type.
See the big `Note [Interesting dictionary arguments]`
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ca7a9d42
by Simon Peyton Jones at 2025-07-12T14:56:16+01:00
Treat tuple dictionaries uniformly; don't unbox them
See `Note [Do not unbox class dictionaries]` in DmdAnal.hs,
sep (DNB1).
This MR reverses the plan in #23398, which suggested a special case to
unbox tuple dictionaries in worker/wrapper. But:
- This was the cause of a pile of complexity in the specialiser (#26158)
- Even with that complexity, specialision was still bad, very bad
See https://gitlab.haskell.org/ghc/ghc/-/issues/19747#note_626297
And it's entirely unnecessary! Specialision works fine without
unboxing tuple dictionaries.
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be7296c9
by Andreas Klebinger at 2025-07-12T14:56:16+01:00
Remove complex special case from the type-class specialiser
There was a pretty tricky special case in Specialise which is no
longer necessary.
* Historical Note [Floating dictionaries out of cases]
* #26158
* #19747 https://gitlab.haskell.org/ghc/ghc/-/issues/19747#note_626297
This MR removes it. Hooray.
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4acf3a86
by Ben Gamari at 2025-07-15T05:46:32-04:00
configure: bump version to 9.15
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45efaf71
by Teo Camarasu at 2025-07-15T05:47:13-04:00
rts/nonmovingGC: remove n_free
We remove the nonmovingHeap.n_free variable.
We wanted this to track the length of nonmovingHeap.free.
But this isn't possible to do atomically.
When this isn't accurate we can get a segfault by going past the end of
the list.
Instead, we just count the length of the list when we grab it in
nonmovingPruneFreeSegment.
Resolves #26186
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af37996e
by Simon Peyton Jones at 2025-07-15T11:42:49+01:00
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
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85c5d59f
by Simon Peyton Jones at 2025-07-15T11:54:06+01:00
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
T16577
T21839r
T5642
Metric Increase:
T15164
T21839c
T5321FD
T5321Fun
WWRec
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ee58ca40
by Simon Peyton Jones at 2025-07-15T11:54:46+01:00
Renaming around predicate types
.. we were (as it turned out) abstracting over
type-class selectors in SPECIALISATION rules!
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9bc53c5a
by Simon Peyton Jones at 2025-07-15T11:54:46+01:00
Small hacky fix to specUnfolding
...just using mkApps instead of mkCoreApps
(This part is likely to change again in a
future commit.)
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ac722078
by Simon Peyton Jones at 2025-07-15T11:54:46+01:00
Slight improvement to pre/postInlineUnconditionally
Avoids an extra simplifier iteration
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30c6d736
by Simon Peyton Jones at 2025-07-15T11:54:46+01:00
Accept GHCi debugger output change
@alt-romes says this is fine
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b7607b37
by Simon Peyton Jones at 2025-07-15T17:52:23+01:00
Wibbles