[Git][ghc/ghc][wip/int64-everywhere] 41 commits: withTimings: Emit allocations counter

[John Ericson]

John Ericson pushed to branch wip/int64-everywhere at Glasgow Haskell Compiler / GHC


Commits:
1bc104b0 by Ben Gamari at 2020-11-29T15:33:18-05:00
withTimings: Emit allocations counter

This will allow us to back out the allocations per compiler pass from
the eventlog. Note that we dump the allocation counter rather than the
difference since this will allow us to determine how much work is done
*between* `withTiming` blocks.

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e992ea84 by GHC GitLab CI at 2020-11-29T15:33:54-05:00
ThreadPaused: Don't zero slop until free vars are pushed

When threadPaused blackholes a thunk it calls `OVERWRITING_CLOSURE` to
zero the slop for the benefit of the sanity checker. Previously this was
done *before* pushing the thunk's free variables to the update
remembered set. Consequently we would pull zero'd pointers to the update
remembered set.

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e82cd140 by GHC GitLab CI at 2020-11-29T15:33:54-05:00
nonmoving: Fix regression from TSAN work

The TSAN rework (specifically aad1f803) introduced a subtle regression
in GC.c, swapping `g0` in place of `gen`. Whoops!

Fixes #18997.

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35a5207e by GHC GitLab CI at 2020-11-29T15:33:54-05:00
rts/Messages: Add missing write barrier in THROWTO message update

After a THROWTO message has been handle the message closure is
overwritten by a NULL message. We must ensure that the original
closure's pointers continue to be visible to the nonmoving GC.

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0120829f by GHC GitLab CI at 2020-11-29T15:33:54-05:00
nonmoving: Add missing write barrier in shrinkSmallByteArray

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8a4d8fb6 by GHC GitLab CI at 2020-11-29T15:33:54-05:00
Updates: Don't zero slop until closure has been pushed

Ensure that the the free variables have been pushed to the update
remembered set before we zero the slop.

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2793cfdc by GHC GitLab CI at 2020-11-29T15:33:54-05:00
OSThreads: Fix error code checking

pthread_join returns its error code and apparently doesn't set errno.

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e391a16f by GHC GitLab CI at 2020-11-29T15:33:54-05:00
nonmoving: Don't join to mark_thread on shutdown

The mark thread is not joinable as we detach from it on creation.

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60d088ab by Ben Gamari at 2020-11-29T15:33:54-05:00
nonmoving: Add reference to Ueno 2016

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3aa60362 by GHC GitLab CI at 2020-11-29T15:33:54-05:00
nonmoving: Ensure that evacuated large objects are marked

See Note [Non-moving GC: Marking evacuated objects].

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8d304a99 by Ben Gamari at 2020-11-30T10:15:22-05:00
rts/m32: Refactor handling of allocator seeding

Previously, in an attempt to reduce fragmentation, each new allocator
would map a region of M32_MAX_PAGES fresh pages to seed itself. However,
this ends up being extremely wasteful since it turns out that we often
use fewer than this.  Consequently, these pages end up getting freed
which, ends up fragmenting our address space more than than we would
have if we had naively allocated pages on-demand.

Here we refactor m32 to avoid this waste while achieving the
fragmentation mitigation previously desired. In particular, we move all
page allocation into the global m32_alloc_page, which will pull a page
from the free page pool. If the free page pool is empty we then refill
it by allocating a region of M32_MAP_PAGES and adding them to the pool.

Furthermore, we do away with the initial seeding entirely. That is, the
allocator starts with no active pages: pages are rather allocated on an
as-needed basis.

On the whole this ends up being a pleasingly simple change,
simultaneously making m32 more efficient, more robust, and simpler.

Fixes #18980.

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b6629289 by Ben Gamari at 2020-11-30T10:15:58-05:00
rts: Use CHECK instead of assert

Use the GHC wrappers instead of <assert.h>.

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9f4efa6a by Ben Gamari at 2020-11-30T10:15:58-05:00
rts/linker: Replace some ASSERTs with CHECK

In the past some people have confused ASSERT, which is for checking
internal invariants, which CHECK, which should be used when checking
things that might fail due to bad input (and therefore should be enabled
even in the release compiler). Change some of these cases in the linker
to use CHECK.

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0f8a4655 by Ryan Scott at 2020-11-30T10:16:34-05:00
Allow deploy:pages job to fail

See #18973.

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49ebe369 by chessai at 2020-11-30T19:47:40-05:00
Optimisations in Data.Foldable (T17867)

This PR concerns the following functions from `Data.Foldable`:
* minimum
* maximum
* sum
* product
* minimumBy
* maximumBy

- Default implementations of these functions now use `foldl'` or `foldMap'`.
- All have been marked with INLINEABLE to make room for further optimisations.

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4d79ef65 by chessai at 2020-11-30T19:47:40-05:00
Apply suggestion to libraries/base/Data/Foldable.hs
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6af074ce by chessai at 2020-11-30T19:47:40-05:00
Apply suggestion to libraries/base/Data/Foldable.hs
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ab334262 by Viktor Dukhovni at 2020-11-30T19:48:17-05:00
dirty MVAR after mutating TSO queue head

While the original head and tail of the TSO queue may be in the same
generation as the MVAR, interior elements of the queue could be younger
after a GC run and may then be exposed by putMVar operation that updates
the queue head.

Resolves #18919

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5eb163f3 by Ben Gamari at 2020-11-30T19:48:53-05:00
rts/linker: Don't allow shared libraries to be loaded multiple times

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490aa14d by Ben Gamari at 2020-11-30T19:48:53-05:00
rts/linker: Initialise CCSs from native shared objects

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6ac3db5f by Ben Gamari at 2020-11-30T19:48:53-05:00
rts/linker: Move shared library loading logic into Elf.c

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b6698d73 by GHC GitLab CI at 2020-11-30T19:48:53-05:00
rts/linker: Don't declare dynamic objects with image_mapped

This previously resulted in warnings due to spurious unmap failures.

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b94a65af by jneira at 2020-11-30T19:49:31-05:00
Include tried paths in findToolDir error

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72a87fbc by Richard Eisenberg at 2020-12-01T19:57:41-05:00
Move core flattening algorithm to Core.Unify

This sets the stage for a later change, where this
algorithm will be needed from GHC.Core.InstEnv.

This commit also splits GHC.Core.Map into
GHC.Core.Map.Type and GHC.Core.Map.Expr,
in order to avoid module import cycles
with GHC.Core.

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0dd45d0a by Richard Eisenberg at 2020-12-01T19:57:41-05:00
Bump the # of commits searched for perf baseline

The previous value of 75 meant that a feature branch with
more than 75 commits would get spurious CI passes.

This affects #18692, but does not fix that ticket, because
if a baseline cannot be found, we should fail, not succeed.

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8bb52d91 by Richard Eisenberg at 2020-12-01T19:57:41-05:00
Remove flattening variables

This patch redesigns the flattener to simplify type family applications
directly instead of using flattening meta-variables and skolems. The key new
innovation is the CanEqLHS type and the new CEqCan constraint (Ct). A CanEqLHS
is either a type variable or exactly-saturated type family application; either
can now be rewritten using a CEqCan constraint in the inert set.

Because the flattener no longer reduces all type family applications to
variables, there was some performance degradation if a lengthy type family
application is now flattened over and over (not making progress). To
compensate, this patch contains some extra optimizations in the flattener,
leading to a number of performance improvements.

Close #18875.
Close #18910.

There are many extra parts of the compiler that had to be affected in writing
this patch:

* The family-application cache (formerly the flat-cache) sometimes stores
  coercions built from Given inerts. When these inerts get kicked out, we must
  kick out from the cache as well. (This was, I believe, true previously, but
  somehow never caused trouble.) Kicking out from the cache requires adding a
  filterTM function to TrieMap.

* This patch obviates the need to distinguish "blocking" coercion holes from
  non-blocking ones (which, previously, arose from CFunEqCans). There is thus
  some simplification around coercion holes.

* Extra commentary throughout parts of the code I read through, to preserve
  the knowledge I gained while working.

* A change in the pure unifier around unifying skolems with other types.
  Unifying a skolem now leads to SurelyApart, not MaybeApart, as documented
  in Note [Binding when looking up instances] in GHC.Core.InstEnv.

* Some more use of MCoercion where appropriate.

* Previously, class-instance lookup automatically noticed that e.g. C Int was
  a "unifier" to a target [W] C (F Bool), because the F Bool was flattened to
  a variable. Now, a little more care must be taken around checking for
  unifying instances.

* Previously, tcSplitTyConApp_maybe would split (Eq a => a). This is silly,
  because (=>) is not a tycon in Haskell. Fixed now, but there are some
  knock-on changes in e.g. TrieMap code and in the canonicaliser.

* New function anyFreeVarsOf{Type,Co} to check whether a free variable
  satisfies a certain predicate.

* Type synonyms now remember whether or not they are "forgetful"; a forgetful
  synonym drops at least one argument. This is useful when flattening; see
  flattenView.

* The pattern-match completeness checker invokes the solver. This invocation
  might need to look through newtypes when checking representational equality.
  Thus, the desugarer needs to keep track of the in-scope variables to know
  what newtype constructors are in scope. I bet this bug was around before but
  never noticed.

* Extra-constraints wildcards are no longer simplified before printing.
  See Note [Do not simplify ConstraintHoles] in GHC.Tc.Solver.

* Whether or not there are Given equalities has become slightly subtler.
  See the new HasGivenEqs datatype.

* Note [Type variable cycles in Givens] in GHC.Tc.Solver.Canonical
  explains a significant new wrinkle in the new approach.

* See Note [What might match later?] in GHC.Tc.Solver.Interact, which
  explains the fix to #18910.

* The inert_count field of InertCans wasn't actually used, so I removed
  it.

Though I (Richard) did the implementation, Simon PJ was very involved
in design and review.

This updates the Haddock submodule to avoid #18932 by adding
a type signature.

-------------------------
Metric Decrease:
    T12227
    T5030
    T9872a
    T9872b
    T9872c
Metric Increase:
    T9872d
-------------------------

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d66660ba by Richard Eisenberg at 2020-12-01T19:57:41-05:00
Rename the flattener to become the rewriter.

Now that flattening doesn't produce flattening variables,
it's not really flattening anything: it's rewriting. This
change also means that the rewriter can no longer be confused
the core flattener (in GHC.Core.Unify), which is sometimes used
during type-checking.

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add0aeae by Ben Gamari at 2020-12-01T19:58:17-05:00
rts: Introduce mmapAnonForLinker

Previously most of the uses of mmapForLinker were mapping anonymous
memory, resulting in a great deal of unnecessary repetition. Factor this
out into a new helper.

Also fixes a few places where error checking was missing or suboptimal.

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97d71646 by Ben Gamari at 2020-12-01T19:58:17-05:00
rts/linker: Introduce munmapForLinker

Consolidates munmap calls to ensure consistent error handling.

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d8872af0 by Ben Gamari at 2020-12-01T19:58:18-05:00
rts/Linker: Introduce Windows implementations for mmapForLinker, et al.

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c35d0e03 by Ben Gamari at 2020-12-01T19:58:18-05:00
rts/m32: Introduce NEEDS_M32 macro

Instead of relying on RTS_LINKER_USE_MMAP

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41c64eb5 by Ben Gamari at 2020-12-01T19:58:18-05:00
rts/linker: Use m32 to allocate symbol extras in PEi386

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a06f9bfa by Sylvain Henry at 2020-12-03T19:40:29+01:00
Fix sized primitives (#19026)

Bump Cabal, array, bytestring, text submodules

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e2e89133 by John Ericson at 2020-12-06T18:24:41+00:00
Cleanup number primop conversion names

Don't use "extend" or "narrow" in some of the user-facing primops
names for conversions.

  - Names like `narrowInt32#` are misleading when `Int` is 32-bits.

  - Names like `extendInt64#` are flat-out wrong when `Int is
    32-bits.

  - `narrow{Int,Word}<N>#` however map a type to itself, and so don't
    suffer from this problem. They are left as-is.

Bumps the array, bytestring, text, and binary submodules

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522796f5 by Sylvain Henry at 2020-12-06T18:34:44+00:00
Make proper fixed-with number literals

(Progress towards #11953, #17377, #17375)

Besides being nicer to use, this also will allow for better constant
folding for the fixed-width types, on par with what `Int#` and `Word#`
have today.

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6d270608 by John Ericson at 2020-12-06T18:41:02+00:00
Make fixed-size `Int32#` and `Int64#`

The boxed Int64 uses Int64#, but Int32# still uses Int#. The 32-bit case
is less pressing to change because it is not a source of brittle
CPP---it is the same thing on all platforms.

We need Int64/Word64 constant folding to avoid the let/app restriction on Core, so
that is implemented now. 32-bit constant unfolding and 32-bit literals
are left as follow-up.

This is the bulk of #11953

Co-authored-by: Sylvain Henry <hsyl20 at gmail.com>

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b906439c by John Ericson at 2020-12-06T18:44:34+00:00
Inline INT64 and WORD64 macros in primops.txt.pp

The definition is now unconditional so there is no reason for that CPP.

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486a09e1 by Sylvain Henry at 2020-12-06T18:44:35+00:00
Adapt rules from #16402 to Word64#/Int64#

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90987f3c by John Ericson at 2020-12-06T18:44:35+00:00
Copy enumFrom* implementations from Int/Word for Int64/Word64

Without this, we don't get proper list fusion.

I think this sort of copying is OK for now, but we absolutely need
something better if we are going to make `IntN` use `IntN#` for all `N`.
The degree to which proper metaprogramming has been punted upon by
factoring everything through the native-sized types is disconcerting.

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2000b4ec by John Ericson at 2020-12-06T18:44:35+00:00
`integerFromInt64#` can be inlined when the word size is >= 64 bits

Maybe this will help with the renaming test failure?

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4bebf98d by John Ericson at 2020-12-06T18:44:35+00:00
Add builtin rule for `divInt64#` and `modInt64#`

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22 changed files:

- .gitlab-ci.yml
- compiler/GHC/Builtin/Names.hs
- compiler/GHC/Builtin/bytearray-ops.txt.pp
- compiler/GHC/Builtin/primops.txt.pp
- compiler/GHC/Cmm/CommonBlockElim.hs
- compiler/GHC/Cmm/Dataflow/Label.hs
- compiler/GHC/Cmm/MachOp.hs
- compiler/GHC/CmmToAsm/PPC/CodeGen.hs
- compiler/GHC/CmmToAsm/Ppr.hs
- compiler/GHC/CmmToAsm/SPARC/CodeGen.hs
- compiler/GHC/CmmToAsm/X86/CodeGen.hs
- compiler/GHC/CmmToC.hs
- compiler/GHC/CmmToLlvm/CodeGen.hs
- compiler/GHC/Core/Coercion.hs
- compiler/GHC/Core/Coercion.hs-boot
- compiler/GHC/Core/Coercion/Axiom.hs
- compiler/GHC/Core/Coercion/Opt.hs
- compiler/GHC/Core/FamInstEnv.hs
- compiler/GHC/Core/InstEnv.hs
- + compiler/GHC/Core/Map/Expr.hs
- compiler/GHC/Core/Map.hs → compiler/GHC/Core/Map/Type.hs
- compiler/GHC/Core/Opt/CSE.hs


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