GitLab

Apoorv Ingle pushed to branch wip/spj-apporv-Oct24 at Glasgow Haskell Compiler / GHC

Commits:

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]`

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.

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.

4acf3a86
by Ben Gamari at 2025-07-15T05:46:32-04:00
```
configure: bump version to 9.15
```

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

c635f164

by Ben Gamari at 2025-07-15T14:05:54-04:00

configure: Drop probing of ld.gold

As noted in #25716, `gold` has been dropped from binutils-2.44.

Fixes #25716.

Metric Increase:
    size_hello_artifact_gzip
    size_hello_unicode_gzip
    ghc_prim_so

637bb538

by Ben Gamari at 2025-07-15T14:05:55-04:00

testsuite/recomp015: Ignore stderr

This is necessary since ld.bfd complains
that we don't have a .note.GNU-stack section,
potentially resulting in an executable stack.

d3cd4ec8
by Wen Kokke at 2025-07-15T14:06:39-04:00
```
Fix documentation for heap profile ID
```
73082769
by Ben Gamari at 2025-07-15T16:56:38-04:00
```
Bump win32-tarballs to v0.9
```

3b63b254

by Ben Gamari at 2025-07-15T16:56:39-04:00

rts/LoadArchive: Handle null terminated string tables

As of `llvm-ar` now emits filename tables terminated with null
characters instead of the usual POSIX `/\n` sequence.

Fixes #26150.

195f6527

by Tamar Christina at 2025-07-15T16:56:39-04:00

rts: rename label so name doesn't conflict with param

63373b95
by Tamar Christina at 2025-07-15T16:56:39-04:00
```
rts: Handle API set symbol versioning conflicts
```

48e9aa3e

by Tamar Christina at 2025-07-15T16:56:39-04:00

rts: Mark API set symbols as HIDDEN and correct symbol type

959e827a

by Tamar Christina at 2025-07-15T16:56:39-04:00

rts: Implement WEAK EXTERNAL undef redirection by target symbol name

65f19293

by Ben Gamari at 2025-07-15T16:56:39-04:00

rts/LoadArchive: Handle string table entries terminated with /

llvm-ar appears to terminate string table entries with `/\n` [1]. This
matters in the case of thin archives, since the filename is used. In the
past this worked since `llvm-ar` would produce archives with "small"
filenames when possible. However, now it appears to always use the
string table.

[1] https://github.com/llvm/llvm-project/blob/bfb686bb5ba503e9386dc899e1ebbe2488e6a0a8/llvm/lib/Object/ArchiveWriter.cpp#L314

9cbb3ef5

by Ben Gamari at 2025-07-15T16:56:39-04:00

testsuite: Mark T12497 as fixed

Thanks to the LLVM toolchain update.

Closes #22694.

2854407e

by Ben Gamari at 2025-07-15T16:56:39-04:00

testsuite: Accept new output of T11223_link_order_a_b_2_fail on Windows

The archive member number changed due to the fact that llvm-ar now uses a
string table.

28439593

by Ben Gamari at 2025-07-15T16:56:39-04:00

rts/linker/PEi386: Implement IMAGE_REL_AMD64_SECREL

This appears to now be used by libc++ as distributed by msys2.

2b053755

by Tamar Christina at 2025-07-15T16:56:39-04:00

rts: Cleanup merge resolution residue in lookupSymbolInDLL_PEi386 and make safe without dependent

e8acd2e7

by Wen Kokke at 2025-07-16T08:37:04-04:00

Remove the `profile_id` parameter from various RTS functions.

Various RTS functions took a `profile_id` parameter, intended to be used to
distinguish parallel heap profile breakdowns (e.g., `-hT` and `-hi`). However,
this feature was never implemented and the `profile_id` parameter was set to 0
throughout the RTS. This commit removes the parameter but leaves the hardcoded
profile ID in the functions that emit the encoded eventlog events as to not
change the protocol.

The affected functions are `traceHeapProfBegin`, `postHeapProfBegin`,
`traceHeapProfSampleString`, `postHeapProfSampleString`,
`traceHeapProfSampleCostCentre`, and `postHeapProfSampleCostCentre`.

76d392a2
by Wen Kokke at 2025-07-16T08:37:04-04:00
```
Make `traceHeapProfBegin` an init event.
```

bbaa44a7

by Peng Fan at 2025-07-16T16:50:42-04:00

NCG/LA64: Support finer-grained DBAR hints

For LA664 and newer uarchs, they have made finer granularity hints
available:

    Bit4: ordering or completion (0: completion, 1: ordering)
    Bit3: barrier for previous read (0: true, 1: false)
    Bit2: barrier for previous write (0: true, 1: false)
    Bit1: barrier for succeeding read (0: true, 1: false)
    Bit0: barrier for succeeding write (0: true, 1: false)

And not affect the existing models because other hints are treated
as 'dbar 0' there.

7da86e16

by Andreas Klebinger at 2025-07-16T16:51:25-04:00

Disable -fprof-late-overloaded-calls for join points.

Currently GHC considers cost centres as destructive to
join contexts. Or in other words this is not considered valid:

    join f x = ...
    in
              ... -> scc<tick> jmp

This makes the functionality of `-fprof-late-overloaded-calls` not feasible
for join points in general. We used to try to work around this by putting the
ticks on the rhs of the join point rather than around the jump. However beyond
the loss of accuracy this was broken for recursive join points as we ended up
with something like:

    rec-join f x = scc<tick> ... jmp f x

Which similarly is not valid as the tick once again destroys the tail call.
One might think we could limit ourselves to non-recursive tail calls and do
something clever like:

  join f x = scc<tick> ...
  in ... jmp f x

And sometimes this works! But sometimes the full rhs would look something like:

  join g x = ....
  join f x = scc<tick> ... -> jmp g x

Which, would again no longer be valid. I believe in the long run we can make
cost centre ticks non-destructive to join points. Or we could keep track of
where we are/are not allowed to insert a cost centre. But in the short term I will
simply disable the annotation of join calls under this flag.

7ee22fd5

by ARATA Mizuki at 2025-07-17T06:05:30-04:00

x86 NCG: Better lowering for shuffleFloatX4# and shuffleDoubleX2#

The new implementation

* make use of specialized instructions like (V)UNPCK{L,H}{PS,PD}, and
* do not require -mavx.

Close #26096

Co-authored-by: sheaf <sam.derbyshire@gmail.com>

c6cd2da1

by Jappie Klooster at 2025-07-17T06:06:20-04:00

Update interact docs to explain about buffering

We need to tell the user to set to the
appropriate buffer format.
Otherwise, this function may get randomly stuck,
or just behave confusingly.

issue: https://gitlab.haskell.org/ghc/ghc/-/issues/26131

NB, I'm running this with cabal *NOT* ghci. ghci messes with buffering anyway.

```haskell
interaction :: String -> String
interaction "jappie" = "hi"
interaction "jakob" = "hello"
interaction x = "unkown input: " <> x

main :: IO ()
main = interact  interaction
```
so in my input (prefixed by `>`) I get:

```
> jappie
unkown input: jappie
```

we confirmed later this was due to lack of \n matching.
Anyway movnig on to more unexpected stuff:

```haskell
main :: IO ()
main = do
  interact  (concatMap interaction . lines)
```

get's stuck forever.
actually `^D` (ctrl+d) unstucks it and runs all input as expected.
for example you can get:
```
> sdfkds
> fakdsf
unkown input: sdfkdsunkown input: fakdsf
```

This program works!
```haskell
interaction :: String -> String
interaction "jappie" = "hi \n"
interaction "jakob" = "hello \n"
interaction x = "unkown input: " <> x <> "\n"

main :: IO ()
main = do
  interact  (concatMap interaction . lines)
```
the reason is that linebuffering is set for both in and output by default.
so lines eats the input lines, and all the \n postfixes make sure the buffer
is put out.

9fa590a6

by Zubin Duggal at 2025-07-17T06:07:03-04:00

fetch_gitlab: Ensure we copy users_guide.pdf and Haddock.pdf to the release docs directory

Fixes #24093

cc650b4b

by Andrew Lelechenko at 2025-07-17T12:30:24-04:00

Add Data.List.NonEmpty.mapMaybe

As per https://github.com/haskell/core-libraries-committee/issues/337

360fa82c

by Duncan Coutts at 2025-07-17T12:31:14-04:00

base: Deprecate GHC.Weak.Finalize.runFinalizerBatch

https://github.com/haskell/core-libraries-committee/issues/342

f4e8466c

by Alan Zimmerman at 2025-07-17T12:31:55-04:00

EPA: Update exact printing based on GHC 9.14 tests

As a result of migrating the GHC ghc-9.14 branch tests to
ghc-exactprint in
https://github.com/alanz/ghc-exactprint/tree/ghc-9.14, a couple of
discrepancies were picked up

- The opening paren for a DefaultDecl was printed in the wrong place
- The import declaration level specifiers were not printed.

This commit adds those fixes, and some tests for them.
The tests brought to light that the ImportDecl ppr instance had not
been updated for level specifiers, so it updates that too.

d70843f8