GitLab

- T12962: just fix function locations
- scc003: reorder cost centres, cost centre `f.(...)` renamed to `f.x'`

Reviewers: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14704

Differential Revision: https://phabricator.haskell.org/D4351

Provide information about paths more likely to be taken in the cmm files
used by the rts.

This leads to slightly better assembly being generated.

Reviewers: bgamari, erikd, simonmar

Subscribers: alexbiehl, rwbarton, thomie, carter

GHC Trac Issues: #14672

Differential Revision: https://phabricator.haskell.org/D4324

... in CmmSink

For code like:
f 1 = e1
f 7 = e2
f _ = e3

We can treat it as a sparse jump table, check if we are outside of the
range in one direction first and then start checking the values.

GHC currently does this by checking for x>7, then x <= 7 and at last x
== 1.

This patch changes this such that we only compare for equality against
the two values and jump to the default if non are equal.

The resulting code is both faster and smaller.
wheel-sieve1 improves by 4-8% depending on problem size.

This implements the idea from #14644

Reviewers: bgamari, simonmar, simonpj, nomeata

Reviewed By: simonpj, nomeata

Subscribers: nomeata, simonpj, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4294

Currently, error messages that germane to GADT constructors
put the source span at only the first character in the constructor,
leading to insufficient caret diagnostics. This can be easily fixed
by using a source span that spans the entire constructor, instead of
just the first character.

Test Plan: make test TEST=T14719

Reviewers: alanz, bgamari, simonpj

Reviewed By: alanz, simonpj

Subscribers: simonpj, goldfire, rwbarton, thomie, carter

GHC Trac Issues: #14719

Differential Revision: https://phabricator.haskell.org/D4344

On Windows we use the function `win32AllocStack` to do stack
allocations in 4k blocks and insert a stack check afterwards
to ensure the allocation returned a valid block.

The problem is this function does something that by C semantics
is pointless. The stack allocated value can never escape the
function, and the stack isn't used so the compiler just optimizes
away the entire function body.

After considering a bunch of other possibilities I think the simplest
fix is to just disable optimizations for the function.

Alternatively inline assembly is an option but the stack check function
doesn't have a very portable name as it relies on e.g. `libgcc`.

Thanks to Sergey Vinokurov for helping diagnose and test.

Test Plan: ./validate

Reviewers: bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14669

Differential Revision: https://phabricator.haskell.org/D4343

This adds a parser-level switch to have 'LINE' and 'COLUMN'
pragmas lexed into actual tokens (as opposed to updating the
position information in the parser).

'lexTokenStream' is the only place where this option is enabled.

Reviewers: bgamari, alexbiehl, mpickering

Reviewed By: mpickering

Subscribers: alanz, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4336

Reasons to remove:
- It's confusing - we already have a widely used `Unique` module in
  `basicTypes/` that defines a newtype called `Unique`
- `Hoopl.Unique` is not actually used much

I've also moved the `Unique{Map,Set}` from `Hoopl.Unique` to
`Hoopl.Collections` to keep things together. But that module is also a
bit funny - it defines two type-classes that have only one instance
each. So we should probably either remove them or use them more
widely... In any case, that will be a separate change.
Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>

Test Plan: ./validate

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: kavon, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4331

Previously `splitEnv` worked like this:

    > splitEnv "foo:::bar::baz:"
    ["foo","","","bar","","baz",""]

with this patch:

    > splitEnv working_dir "foo:::bar:baz:"
    ["foo",working_dir,working_dir"bar","baz",working_dir]

This fixes #14695, where having a trailing `:` in the env variable
caused ghci to pass empty `-B` parameter to `gcc`, which in turned
caused the next parameter (`--print-file-name`) to be considered as the
argument to `-B`. As a result ghci did not work.

The `working_dir` argument is to have a similar behavior with POSIX:
according to chapter 8.3 zero-length prefix means current working
directory.

Reviewers: hvr, bgamari, AndreasK, simonmar

Reviewed By: bgamari, AndreasK, simonmar

Subscribers: AndreasK, rwbarton, thomie, carter

GHC Trac Issues: #14695

Differential Revision: https://phabricator.haskell.org/D4330

This is an initial attempt at tackling the issue of how to order the
suggestions provided by the valid substitutions checker, by sorting
them by creating a graph of how they subsume each other. We'd like to
order them in such a manner that the most "relevant" suggestions are
displayed first, so that the suggestion that the user might be looking
for is displayed before more far-fetched suggestions (and thus also
displayed when they'd otherwise be cut-off by the
`-fmax-valid-substitutions` limit). The previous ordering was based on
the order in which the elements appear in the list of imports, which I
believe is less correlated with relevance than this ordering.

A drawback of this approach is that, since we now want to sort the
elements, we can no longer "bail out early" when we've hit the
`-fmax-valid-substitutions` limit.

Reviewers: bgamari, dfeuer

Reviewed By: dfeuer

Subscribers: dfeuer, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4326

This is an obvious optimisation whose overhead is neglectable but
which significantly simplifies the common uses of `compareByteArrays#`
which would otherwise require to make *careful* use of
`reallyUnsafePtrEquality#` or (equally fragile) `byteArrayContents#`
which can result in less optimal assembler code being generated.

Test Plan: carefully examined generated cmm/asm code; validate via phab

Reviewers: alexbiehl, bgamari, simonmar

Reviewed By: bgamari, simonmar

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4319

Adding the ability to parse likely flags in Cmm allows better codegen
for cmm files.

Test Plan: ci

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14672

Differential Revision: https://phabricator.haskell.org/D4316

It's better to fall through to the likely case than to jump to it.

We optimize for this in CmmContFlowOpt when likely:False.
This commit extends the logic there to handle cases with likely:True
as well.

Test Plan: ci

Reviewers: bgamari, simonmar

Reviewed By: bgamari

Subscribers: simonmar, alexbiehl, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4306

Test Plan: Validate

Reviewers: hvr, dfeuer

Reviewed By: dfeuer

Subscribers: dfeuer, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4304

The GHC-side `getNameToInstancesIndex` filters out incorrectly some
instances because it is not aware of what modules are visible. Using
`runTcInteractive` means that `ie_visible` gets initialized to a one
module set containing some dummy GHCi module. This is clearly not the
module set we want to check against to see if a given orphan instance
is visible or not.

In fact, GHC has no way of knowing what we want that module set to be
since it doesn't know ahead of time which modules Haddock is making its
docs for. The fix is just to pass that set in as an argument.

Bumps haddock submodule.

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: duog, alexbiehl, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4290

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4334

Ideally, I'd like to do

    type EvTerm = CoreExpr

and the type checker builds the evidence terms as it goes. This failed,
becuase the evidence for `Typeable` refers to local identifiers that are
added *after* the typechecker solves constraints. Therefore, `EvTerm`
stays a data type with two constructors: `EvExpr` for `CoreExpr`
evidence, and `EvTypeable` for the others.

Delted `Note [Memoising typeOf]`, its reference (and presumably
relevance) was removed in 8fa4bf9a.

Differential Revision: https://phabricator.haskell.org/D4341

See Note [Lone variables] in CoreUnfold and
Note [exprIsExpandable] in CoreUtils.

Helpfully pointed out by Matthew Pickering in Trac #14688

Nofib results are good:

--------------------------------------------------------------------------------
        Program           Size    Allocs   Runtime   Elapsed  TotalMem
--------------------------------------------------------------------------------
           anna          +0.1%     +0.3%     0.151     0.151      0.0%
         awards          +0.0%     -0.2%     0.001     0.001      0.0%
      compress2          +0.6%     -0.7%     -4.8%     -5.0%     -4.0%
          eliza          +0.0%     -2.4%     0.001     0.001      0.0%
         fulsom          +0.4%    -13.3%     -7.6%     -7.6%   +190.0%
         gamteb          +0.0%     -0.6%     0.062     0.062      0.0%
             gg          +0.1%     -0.4%     0.016     0.016      0.0%
            ida          +0.1%     +0.3%     0.110     0.110      0.0%
          kahan          +0.0%     -0.7%     -0.9%     -0.9%      0.0%
           mate          +0.1%     -5.2%     -4.9%     -4.9%      0.0%
         n-body          +0.0%     -0.2%     -0.3%     -3.0%      0.0%
         pretty          +0.0%     -2.8%     0.000     0.000      0.0%
            scs          +0.0%     -0.2%     +1.6%     +2.4%      0.0%
         simple          +0.4%     -0.2%     -2.3%     -2.3%     -3.4%
        veritas          +0.4%     -1.0%     0.003     0.003      0.0%
           wang          +0.0%     -1.6%     0.165     0.165      0.0%
--------------------------------------------------------------------------------
            Min          -0.0%    -13.3%    -16.2%    -18.8%     -4.0%
            Max          +0.6%     +0.3%     +4.9%     +4.9%   +190.0%
 Geometric Mean          +0.1%     -0.3%     -1.7%     -2.4%     +0.9%

Richard was confused; I hope these comments help.

This gives a 10% allocation improvement on MultiLayerModules.
The idea is to reuse existing tuples, instead of constantly
constructing new ones.

Test Plan: ./validate

Reviewers: simonpj, bgamari

Reviewed By: simonpj, bgamari

Subscribers: rwbarton, thomie, simonmar, carter

Differential Revision: https://phabricator.haskell.org/D4332

Not doing so resulted in different uniques being printed on different
environments, as shown in #14703.

- Cabal-2.2 uses SPDX license identifiers, so I had to update
  `cabal-version: 2.1` packages `license: BSD3` to `license: BSD-3-Clause`
- `ghc-cabal` used old ReadP parsec, now it uses `parsec` too
- InstalledPackageInfo pretty-printing have changed a little,
  fields with default values aren't printed. This can be changed in
  `Cabal` still, but I haven't found problems with omitting them.

Note: `BSD-3-Clause` is parsed as "name = BSD, version = 3" by old
parser (because 3-Clause looks like version 3 with tag Clause).
If you see *"BSD-3" is not a valid license*, then something is using
old parser still.

Fixes #9885.

I noticed while trying to test against LLVM 5.0 that GHC would throw "Couldn't
figure out linker information" warnings due to LLD being chosen by configure.
Adding detection support to silence these is simple enough, let's just do it.

Before this change, a list was used as a substitute for a heap.
This led to quadratic behavior on a simple program (see new
test case).

This change replaces it with IntSet in effect reverting
5a1a2633. @simonmar said it's fine to revert as long as nofib
results are good.

Test Plan:
new test case:

20% improvement
3x improvement when N=10000

nofib:

I run it twice for before and after because the compile time
results are noisy.

- Compile Allocations:

```
          before    before re-run    after     after re-run
-1 s.d.   -----     -0.0%            -0.1%     -0.1%
+1 s.d.   -----     +0.0%            +0.1%     +0.1%
Average   -----     +0.0%            -0.0%     -0.0%
```
- Compile Time:

```
          before    before re-run    after     after re-run
-1 s.d.   -----     -0.1%            -2.3%     -2.6%
+1 s.d.   -----     +5.2%            +3.7%     +4.4%
Average   -----     +2.5%            +0.7%     +0.8%

```
I checked each case and couldn't find consistent slow-down/speed-up on
compile time. Full results here: P173

Reviewers: simonpj, simonmar, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter, simonmar

GHC Trac Issues: #14667

Differential Revision: https://phabricator.haskell.org/D4329

Implement the proposal of underscores in numeric literals.
Underscores in numeric literals are simply ignored.

The specification of the feature is available here:
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/000
9-numeric-underscores.rst

For a discussion of the various choices:
https://github.com/ghc-proposals/ghc-proposals/pull/76

Implementation detail:

* Added dynamic flag
  * `NumericUnderscores` extension flag is added for this feature.

* Alex "Regular expression macros" in Lexer.x
  * Add `@numspc` (numeric spacer) macro to represent multiple
    underscores.
  * Modify `@decimal`, `@decimal`, `@binary`, `@octal`, `@hexadecimal`,
    `@exponent`, and `@bin_exponent` macros to include `@numspc`.

* Alex "Rules" in Lexer.x
  * To be simpler, we have only the definitions with underscores.
    And then we have a separate function (`tok_integral` and `tok_frac`)
    that validates the literals.

* Validation functions in Lexer.x
  * `tok_integral` and `tok_frac` functions validate
    whether contain underscores or not.
    If `NumericUnderscores` extensions are not enabled,
    check that there are no underscores.
  * `tok_frac` function is created by merging `strtoken` and
    `init_strtoken`.
  * `init_strtoken` is deleted. Because it is no longer used.

* Remove underscores from target literal string
  * `parseUnsignedInteger`, `readRational__`, and `readHexRational} use
    the customized `span'` function to remove underscores.

* Added Testcase
  * testcase for NumericUnderscores enabled.
      NumericUnderscores0.hs and NumericUnderscores1.hs
  * testcase for NumericUnderscores disabled.
      NoNumericUnderscores0.hs and NoNumericUnderscores1.hs
  * testcase to invalid pattern for NumericUnderscores enabled.
      NumericUnderscoresFail0.hs and NumericUnderscoresFail1.hs

Test Plan: `validate` including the above testcase

Reviewers: goldfire, bgamari

Reviewed By: bgamari

Subscribers: carter, rwbarton, thomie

GHC Trac Issues: #14473

Differential Revision: https://phabricator.haskell.org/D4235

Rename to whitehole_gc_spin, in preparation for adding stats for the
whitehole busy-loop in SMPClosureOps.

Make whitehole_gc_spin volatile, and move it to be defined and
statically initialised in GC.c. This saves some #ifs, and I'm pretty
sure it should be volatile.

Test Plan: ./validate

Reviewers: bgamari, erikd, simonmar

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D4300

This is an attempt at clarifying the docs for HasCallStack in both the
user guide and libraries/base/GHC/Stack/Types.hs. The example used right
now is built around an hypothetical 'error' function that doesn't itself
print call stacks, and the fact that this doesn't hold makes it all
confusing, see #14635.

Reviewers: hvr, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14635

Differential Revision: https://phabricator.haskell.org/D4317

A silly mistake in `gen_Show_binds` was causing derived
`Show` instances for empty data types to case on the precedence
argument instead of the actual value being showed.

Test Plan: make test TEST=drv-empty-data

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14692

Differential Revision: https://phabricator.haskell.org/D4328

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14670

Differential Revision: https://phabricator.haskell.org/D4314

This adds support for the bit deposit and extraction operations provided
by the BMI and BMI2 instruction set extensions on modern amd64 machines.

Implement x86 code generator for pdep and pext.  Properly initialise
bmiVersion field.

pdep and pext test cases

Fix pattern match for pdep and pext instructions

Fix build of pdep and pext code for 32-bit architectures

Test Plan: Validate

Reviewers: austin, simonmar, bgamari, angerman

Reviewed By: bgamari

Subscribers: trommler, carter, angerman, thomie, rwbarton, newhoggy

GHC Trac Issues: #14206

Differential Revision: https://phabricator.haskell.org/D4236

Subscribers: rwbarton, thomie

GHC Trac Issues: #14335

Differential Revision: https://phabricator.haskell.org/D4202

It turns out that `Convert` was recklessly leaving off
parentheses in two places:

* Negative numeric literals
* Patterns in lambda position

This patch fixes it by adding three new functions, `isCompoundHsLit`,
`isCompoundHsOverLit`, and `isCompoundPat`, and using them in the
right places in `Convert`. While I was in town, I also sprinkled
`isCompoundPat` among some `Pat`-constructing functions in `HsUtils`
to help avoid the likelihood of this problem happening in other
places. One of these places is in `TcGenDeriv`, and sprinkling
`isCompountPat` there fixes #14682

Test Plan: make test TEST="T14681 T14682"

Reviewers: alanz, goldfire, bgamari

Reviewed By: bgamari

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #14681, #14682

Differential Revision: https://phabricator.haskell.org/D4323