GitLab

It was removed long ago in cf403b50.
Thanks for @rwbarton for catching this.

Updates nofib submodule.

Test Plan: Validate

Reviewers: austin, rwbarton

Subscribers: thomie, rwbarton

Differential Revision: https://phabricator.haskell.org/D2493

GHC Trac Issues: #12443

maxWorkerArgs handling was accidentally lost 3 years ago
in a major update of demand analysis
    commit 0831a12e

Old regression is noticeable as:
- code bloat (requires stack reshuffling)
- compilation slowdown (more code to optimise/generate)
- and increased heap usage (DynFlags unboxing/reboxing?)

On a simple compile benchmark this change causes heap
allocation drop from 70G don to 67G (ghc perf build).
Signed-off-by: Sergei Trofimovich <siarheit@google.com>

Reviewers: simonpj, ezyang, goldfire, austin, bgamari

Reviewed By: simonpj, ezyang

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2503

GHC Trac Issues: #11565

It will be included in 8.0.2

This reverts commit ca6d0eb0.

I'm really not sure what happened with the test build that lead me to
believe that this was necessary. Mysterious.

Reviewers: austin

Subscribers: simonpj, ezyang, thomie

Differential Revision: https://phabricator.haskell.org/D2466

We need to compare against the local return and pure, not returnMName
and pureAName.

Fixes #12490.

Test Plan: Validate, add testcase

Reviewers: austin, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2499

GHC Trac Issues: #12490

Removes -Wredundant-constraints from -Wall, as per the
discussion in #10635.

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2498

GHC Trac Issues: #10635

Reviewers: simonpj, thomie, austin, bgamari

Reviewed By: simonpj, thomie, bgamari

Subscribers: simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D2458

GHC Trac Issues: #12170

Sadly I don't know precisely which commit regressed this, but it was
quite recent. I'm not sure how this wasn't caught by my test builds.

According to the ABI specifications a minimal stack frame consists
of a header and a minimum size parameter save area. We reserve the
minimal size for each ABI.

On PowerPC 64-bil Linux and AIX the parameter save area can accomodate
up to eight parameters. So calls with eight parameters and fewer
can be done without allocating a new stack frame and deallocating
that stack frame after the call. On AIX one additional spill slot
is available on the stack.

Code size for all nofib benchmarks is 0.3 % smaller on powerpc64.

Test Plan: validate on AIX

Reviewers: hvr!, erikd, austin, simonmar, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2445

Reviewers: thomie, bgamari, austin

Reviewed By: thomie, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2461

GHC Trac Issues: #9089

This adds new methods `liftReadList(2)` and `liftReadListPrec(2)` to the
`Read1`/`Read2` classes which are defined in terms of `ReadPrec` instead
of `ReadS`. This also adds related combinators and changes existing
`Read1` and `Read2` instances to be defined in terms of the new methods.

Reviewers: hvr, austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2379

GHC Trac Issues: #12358

Test Plan: Validate

Reviewers: austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2465

Test Plan: it's just a testcase

Reviewers: ezyang, simonmar, bgamari, austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2450

GHC Trac Issues: #12485

Test Plan: Validate

Reviewers: austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2491

GHC Trac Issues: #12206

Just as it says on the can

Test Plan: validate

Reviewers: austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2489

GHC Trac Issues: #12091

The current haddocks do not specify the scope of the state manipulated
by `getQ`/`putQ`.

Reviewers: austin, goldfire, bgamari, ezyang

Reviewed By: ezyang

Subscribers: ezyang, thomie

Differential Revision: https://phabricator.haskell.org/D2497

Test Plan: Good question

Reviewers: austin, trommler, simonmar, rrnewton

Reviewed By: simonmar

Subscribers: RyanGlScott, thomie

Differential Revision: https://phabricator.haskell.org/D2495

GHC Trac Issues: #12469

This is long overdue.

Perhaps 1MB is a little on the skinny size, but this is based on
* A lot of commodity dual-core desktop processors have 3MB L3 cache
* We're traditionally quite frugal with memory by default

Test Plan: validate

Reviewers: erikd, bgamari, hvr, austin, rwbarton, ezyang

Reviewed By: ezyang

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2496

Test Plan: validate

Reviewers: simonmar, erikd, austin

Reviewed By: simonmar, erikd

Subscribers: thomie, erikd

Differential Revision: https://phabricator.haskell.org/D2494

GHC Trac Issues: #12491

Test Plan: Validate

Reviewers: austin, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2492

GHC Trac Issues: #12398

Test Plan: None.

Reviewers: austin, simonmar

Reviewed By: simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2487

In outHsLine, paths passed to construct invocations of hsc_line must be
escaped twice in order to generate a properly escaped string literal
that will end up in the eventual LINE pragma emitted by this code. This
is especially important on Windows paths, where backslashes would
otherwise be treated as C escape sequences and result in the incorrect
Windows paths.

Adds test case to verify that hsc2hs properly escapes file paths in LINE
pragmas

Updates the hsc2hs submodule.

See https://ghc.haskell.org/trac/ghc/ticket/12504

Reviewers: erikd, hvr, austin, bgamari, Phyx

Reviewed By: erikd, Phyx

Subscribers: thomie, Phyx, mpickering

Differential Revision: https://phabricator.haskell.org/D2478

GHC Trac Issues: #12504

Previously interpreting the content of the .ghc.env files was done
after the step that loaded the available package dbs. This meant that
setting the package db flags was ineffective. This patch moves
interpreting the env files before loading of the package dbs.

Also, the package-db entries refer to files. Allow spaces in these file
names. Also treat as comments lines beginning with "--".

These are pretty minor fixes in a feature that up 'til now has been
essentially unused (witness no bug report about it), so there's very
low risk here. If we can get this into 8.0.2 then cabal can start
generating the .ghc.environment files, otherwise it cannot as it needs
the working package-db entries, to be able to refer to local package
dbs in the build tree (or cabal nix store).

Test Plan:
Manually create example .ghc.env files
run ghci; :show packages
Done this. It works.

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2476

Instead of stg_interp_constr_entry there are now 7 functions (one for
each value of the tag bits) that tag the constructor pointer before
returning. This is consistent with compiled constructors' entry code,
and expectations that compiled code places on compiled constructors. The
iserv protocol is extended with an extra field that explains what
pointer tag the constructor should use.

Test Plan: Added tests for #12523

Reviewers: erikd, bgamari, hvr, austin, simonmar

Reviewed By: simonmar

Subscribers: osa1, thomie, rwbarton

Differential Revision: https://phabricator.haskell.org/D2473

GHC Trac Issues: #12523

In the previous patch, I handled lazy @(Int -> Int) f x
correctly, but failed to handle lazy @Int (f x) (we need
to collect arguments in f x).
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Test Plan: validate

Reviewers: simonpj, austin, bgamari, nomeata

Reviewed By: nomeata

Subscribers: simonmar, thomie

Differential Revision: https://phabricator.haskell.org/D2471

Reviewers: austin, bgamari, ezyang

Reviewed By: ezyang

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2464

Reviewers: austin, thomie, bgamari

Reviewed By: bgamari

Differential Revision: https://phabricator.haskell.org/D2463

GHC Trac Issues: #12517

I think someone accidentally a word in a Note in TcGenDeriv.

Parallel GC does not scan large allocation area (-A)
effectively as it does not do work stealing from nursery
by default.

That leads to large imbalance when only one of threads
overflows allocation area: most of GC threads finish
quickly (as there is not much to collect) and sit idle
waiting while single GC thread finishes scan of single
allocation area for that thread.

The patch enables work stealing for (equivalent of -qb0)
allocation area of -A32M or higher.

Tested on a highlighting-kate package from Trac #9221

On 8-core machine the difference is around 5% faster
of wall-clock time. On 24-core VM the speedup is 20%.
Signed-off-by: Sergei Trofimovich <siarheit@google.com>

Test Plan: measured wall time and GC parallelism on highlighting-kate build

Reviewers: austin, bgamari, erikd, simonmar

Reviewed By: bgamari, simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2483

GHC Trac Issues: #9221

In Trac #9221 one of problems using high --jobs=<N>
is amount of mutator (or GC) threads we crate.

We use userspace spinning-and-yielding (see ACQUIRE_SPIN_LOCK)
to acess work stealing queues. In case of
N-worker-threads > N-CPUs fraction of time when
thread holding spin lock gets descheduled by kernel
increases. That causes other threads to waste CPU time
before giving up CPU.
Signed-off-by: Sergei Trofimovich <siarheit@google.com>

Test Plan:
ghc --make -j8 and -j80 have comparable sys time
on a 8-core system.

Reviewers: austin, gintas, bgamari, simonmar

Reviewed By: bgamari, simonmar

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2482

GHC Trac Issues: #9221

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Summary:
Back when derived `Generic` instances used to generate auxiliary datatypes,
they would also generate instances for those datatypes. Nowadays, GHC generics
uses a `DataKinds`-based encoding that requires neither auxiliary datatypes
(corresponding to the `DerivTyCon` constructor of `DerivStuff`) nor instances
for them (the `DerivInst` constructor of `DerivStuff`). It appears that
`DerivTyCon` constructor was removed at some point, but `DerivInst` never was.

No `DerivInst` values are ever constructed, so we can safely remove it.

Test Plan: It builds

Reviewers: austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2481

Summary: Fixes #12530.

Test Plan: make test TEST=12530

Reviewers: austin, bgamari, hvr, goldfire

Reviewed By: goldfire

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2472

GHC Trac Issues: #12530

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>