Duncan Coutts pushed to branch wip/dcoutts/io-manager-io-primop-exceptions at Glasgow Haskell Compiler / GHC Commits: b9160962 by Simon Jakobi at 2026-08-20T14:57:52-04:00 testsuite: Show baseline sample count and range in perf failures A perf baseline is the mean of all samples recorded for a commit, and it prints as a single number, hiding how far the samples spread. When the spread is wide, this can indicate an unstable metric that isn't actually useful as a signal for the perf tests. For example, in #27602, T27336's peak_megabytes_allocated baseline showed as 757 when the underlying samples were 605 and 909. When the baseline is averaged from more than one sample, say so in the failure output: the one-line stat-failure reason shows the sample range, and the detail block lists the raw samples. Single-sample baselines print exactly as before. Context: #27602 Assisted-by: Claude Fable 5 - - - - - a4979877 by Simon Jakobi at 2026-08-20T14:57:52-04:00 testsuite: Fold Baseline into CommitMetric A Baseline was just a CommitMetric plus the commit it came from, built by copying fields across. Since get_commit_metric already knows that commit, record it on CommitMetric itself and drop Baseline. This also collapses both branches of find_baseline into plain returns. Assisted-by: Claude Fable 5 - - - - - 99fb8d68 by Simon Jakobi at 2026-08-20T14:57:52-04:00 ci: Clarify comment on pushing perf notes after failures Context: #27602 Assisted-by: Claude Fable 5 - - - - - 2ca87972 by Alan Zimmerman at 2026-08-20T14:58:36-04:00 EPA: Remove LocatedBC / SrcSpanBF The custom annotations are now in the BooleanFormula TTG extension points, so LBooleanFormula can now use the standard LocatedA. - - - - - d2bc32aa by Simon Peyton Jones at 2026-08-21T12:59:26-04:00 Better handling of serialisation of wired-in names Fixes #27501 - - - - - d2795ffc by Alan Zimmerman at 2026-08-21T13:00:05-04:00 EPA: Remove NoEpTok/NoEpUniTok, using an unhelpful SrcSpan instead Also introduce helper functions noEpTok and noEpUniTok to serve as simple replacements in code inserting an token annotation without location information. - - - - - b5d29ab8 by Brandon Chinn at 2026-08-25T18:42:08-04:00 Add Data.RealFloat and Infinity/NegInfinity/NaN pattern synonyms (#26961) - - - - - e60eb3bc by Andreas Klebinger at 2026-08-25T18:42:59-04:00 rts linker: Fix pointer arithmetic issue in flushInstructionCacheRISCV64 We accidentally operated over `uint64_t*` when we should use `uint8_t`. Fixes #27569 - - - - - e9bbe8f9 by Andreas Klebinger at 2026-08-26T15:09:23-04:00 cmm dumps: Add machop width info with -dppr-debug for infix ops. - - - - - 86e3a9d8 by Andreas Klebinger at 2026-08-26T15:09:24-04:00 CmmLint: Check for unsupported MachOp widths machOpArgReps now maps MachOp + Width to a list of supported argument widths or Nothing if the given operation is not supported at the given width. This allows us to check for nonsensical combinations like FloatToInt at Word16. Similarly we now check that every address is actually wordwidth. - - - - - 13781cca by Andreas Klebinger at 2026-08-26T15:09:24-04:00 arm64 ncg: The big subword truncation fix. A set of slightly related fixes to arm subword handling: Bitmask immediates: Don't produce overflowing assembly literals. There is still another bug here that causes us to miss some valid literals but we will fix that later. Improve subword truncation handling: We now use a small set of helpers to truncate `Register` values rather than truncating immediate `Reg` values which greatly simplifies the code structure. This fixes a great many bugs to do with sign/zero extending subwords or the lack thereof. We now establish the invariant that subword values are zero-extended at every site at which they come into "scope" of the ncg, and rely on the invariant throughout rather than pessimistically inserting redundant extensions in a hodgepodge manner at the use sites of these values. This fixes at least the bugs described in issues #27533, #27430 #27537, #27538, #27539, and #27550. But likely more bugs yet not found. Subword ffi results: Apply truncations when calling functions returning subword values. genCondJump: Don't sign extend signed values in the input register as it might map to a local variable, corrupting the value stored within. Fix subword store/load instructions.: We used to read those at 32bit width even for smaller values possibly resulting in invalid memory access. Now we construct the suffix for subword variants based on the instruction format for these. - - - - - d8fa5d7c by Andreas Klebinger at 2026-08-26T15:09:24-04:00 arm64 ncg: Fix MO_V_Broadcast for non-literals. We now use OpReg instead of OpScalarAsVec as required since we broadcast a gp register. Also adds a test. Fixes #27565. - - - - - 94822c95 by Andreas Klebinger at 2026-08-26T15:09:24-04:00 Add some test cases covering bugs in the arm ncg. * Test for #27430 (subword ffi results) * #27537 - subword conversions * #27538 - subwords used in conditional * #27533 - single byte read - - - - - dd1ba88a by Andreas Klebinger at 2026-08-26T15:09:24-04:00 cmmLint: Lint against MO_FS_Truncate subword use. - - - - - fd22f71e by Zubin Duggal at 2026-08-26T15:10:20-04:00 ghc-internal: annotateSTM should use catchSTM# rather than catch# A catch# frame inside a transaction breaks retry and async exception delivery. Fixes #27657 - - - - - bb324171 by Rodrigo Mesquita at 2026-08-26T15:10:59-04:00 rts: refactor to reduce THREADED_RTS in MSG_UPD_TSO_FLAGS - No behavior change in this commit (well, a small optimization here makes us do less work if the target TSO owned by the curr. capability) - Move all THREADED_RTS CPP needed into `updThreadFlag` - Merge MSG_SET_TSO_FLAGS and MSG_UNSET_TSO_FLAGS into MSG_UPD_TSO_FLAGS plus a `set` bool field in the MessageUpdTSOFlag struct Towards #27729 - - - - - ed99b7b7 by Rodrigo Mesquita at 2026-08-26T15:10:59-04:00 rts: Fix race condition in MSG_UPD_TSO_FLAGS execution The code for processing the MSG_UPD_TSO_FLAGS message was not taking into consideration that the TSO's owner might have moved in between that capability receiving the message (since it was its previous owner) and starting to process its inbox (a point at which it was no longer the owner) Added Note [TSO owner may change in between Msg being sent and received] to explain this race and the pattern used to fix this, where we just forward the message to the new owner. Fixes #27729 - - - - - cd653714 by Alan Zimmerman at 2026-08-26T15:11:49-04:00 EPA: Uses Parsers.parseModule for exactprint tests Parsers.parseModule is the advertised way to parse for use for exact printing in the ghc-exactprint library. This commit updates the GHC exact print testing to use it. This requires moving the comment balancing that was occurring only in the test path into the advertising parser path, so it moves from Transforms.hs to Utils.hs. Also update the comment adding to honour trailing annotations - - - - - d1d01fa5 by Wolfgang Jeltsch at 2026-08-27T13:17:59+03:00 Add `rethrowSTM` and improve STM-related documentation Adding `rethrowSTM` resolves #26758. The implementation of `rethrowSTM` is completely analogous to the one of `rethrowIO`. The following is established for the documentation of `throwSTM` and `catchSTM`: * Both operations are directly described as analogs of their `IO` counterparts. * There is no reference to `throw` in the documentation of `throwSTM`, because, although such a reference is great in the documentation of `throwIO`, it is somewhat out of place in the documentation of `throwSTM`. * Instead of repeating part of `throwIO`’s documentation, the documentation of `throwSTM` just recommends using `throwSTM` instead of `throw` and references the corresponding arguments in the documentation of `throwIO`. - - - - - 06fde293 by fendor at 2026-08-28T06:06:44-04:00 GHCi: Fix order of `PackageDBFlag`s for interactive home unit `PackageDBFlag`s are stored in reverse order of cli specification. When sorting the `PackageDBFlag`s by longest common prefix, we need thus to reverse the package db stacks before calculating the prefix. We make sure to reverse the package db stack for the interactive home unit to uphold that later specified package dbs overwrite earlier ones. Resolved and adds regression test for #27640 - - - - - 024c4d04 by fendor at 2026-08-28T06:07:23-04:00 Reuse the UnitIndexCache after initialising multiple home units - - - - - 55326fa0 by Alan Zimmerman at 2026-08-28T06:08:03-04:00 EPA: Some Haddock processing tweaks These changes to the Haddock postprocessing should not change behaviour, but just bring it more closely in line with the original, changed at 44309cd377f And add some haddock exactprint tests to show they work. - - - - - b3ddee95 by Andreas Klebinger at 2026-08-28T13:57:46-04:00 hadrian: Deprecate quickest flavour. It was more of a trap for new users than actually beneficial so we deprecate it and suggest quick+no_dynamic_libs to users instead. - - - - - a1d81390 by Andreas Klebinger at 2026-08-28T13:58:37-04:00 cmm: Always favour entry block during block deduplication. We now always keep the first block in the CmmGraph. This way we avoid the need to update the entry info table. Failing to do so caused #27722. Fixes #27722. - - - - - 5bd65f00 by Andreas Klebinger at 2026-08-28T13:59:16-04:00 test: FamAppCachePerf - Only collect bytes allocated. Fixes 27747 - - - - - ced53ce6 by mangoiv at 2026-08-29T07:15:24-04:00 nightlies: output yaml to file only Previously we would just output the metadata to stdout which risks that it's clobbered by incidental debugt output. We now output to file only. Fixes #27511 - - - - - 578bd185 by Andreas Klebinger at 2026-08-29T07:16:05-04:00 Specialise: Stop looping on recursive dictionaries in interestingDict interestingDict now doesn't look through loopbreaker unfoldings. Doing so would cause infinite loops on certain dictionaries. Fixes #27705. - - - - - fd0a756d by Duncan Coutts at 2026-08-29T20:56:47+01:00 Reorder cmm decls in HeapStackCheck for a better logical grouping And put more section headers in to deliniate the groups. We're about to add more here, so better to organise it first. - - - - - 8ca34d49 by Duncan Coutts at 2026-08-29T20:56:47+01:00 Add raisePrimIOException and add it to RTS<->ghc-internal API The raisePrimIOException is a new helper function that I/O primops will use to help them report I/O errors. This is implemented in Haskell (since that's a lot easier), but has a calling convention that is easy(ish) to use from Cmm in the I/O primops. So we add it to the RTS API struct, and since we'll use it from Cmm we also need a field accessor macro for cmm (in deriveConstants). See the Note about how we cannot have nice things due to async exceptions and thunks preventing us from using catch. - - - - - e929a86a by Duncan Coutts at 2026-08-29T20:56:47+01:00 Add new blocking functions for I/O primops See the long Note. The point is, it will allow us to report synchronous exceptions from I/O primops, and do so much more flexibly. Previously the I/O managers could only report async exceptions and only nullary exceptions. This was OK historically, but no good as we add more I/O managers and expand the range of I/O operations we support. - - - - - 182c2b34 by Duncan Coutts at 2026-08-29T21:24:53+01:00 Change the encoding of results from the I/O manager to I/O primops Previously we just had async continue or heap overflow. We now extend what we can report with synchronous success, and synchronous failure with an errno. See Note [Encoding of result of I/O manager operations] We don't use these two new cases yet, but we will. In particular an epoll I/O manager needs to be able to report synchronous success or failure for waitRead#/waitWrite#. - - - - - 3cdf9edf by Duncan Coutts at 2026-08-29T21:24:53+01:00 Switch waitRead/Write# to use new blocking return frames and update the I/O managers to set the result before resuming the blocked threads. This makes it possible for I/O managers to report synchronous exceptions from the I/O primops, but that will be done in a subsequent commit. - - - - - 7615480e by Duncan Coutts at 2026-08-29T21:24:53+01:00 Switch Poll and Select I/O managers to report sync exceptions rather than using raiseAsync with blockedOnBadFD_closure. This uses the new mechanism in the blocking frame return code to report synchronous exceptions. - - - - - 591faa30 by Duncan Coutts at 2026-08-29T21:24:53+01:00 Remove now-unused blockedOnBadFD It was previously thrown by the select and poll I/O managers, but now they use raisePrimIOException (with an EBADF errno). - - - - - 7bd39b65 by Duncan Coutts at 2026-08-29T21:24:53+01:00 Improve the docs for delay# waitRead# and waitWrite# Document that the waitRead/Write# can throw exceptions (this was true before too), and that all of them are async exception cancellation points. - - - - - 152 changed files: - .gitlab-ci.yml - .gitlab/ci.sh - .gitlab/rel_eng/mk-ghcup-metadata/mk_ghcup_metadata.py - changelog.d/T27202 - + changelog.d/T27657 - + changelog.d/T27705 - + changelog.d/T27722-cbe-entry-block.md - + changelog.d/arm_ncg_fixes_T27430 - + changelog.d/rethrow-stm - changelog.d/unit-index - compiler/GHC/Builtin.hs - compiler/GHC/Builtin/primops.txt.pp - compiler/GHC/Cmm/CommonBlockElim.hs - compiler/GHC/Cmm/Expr.hs - compiler/GHC/Cmm/Lint.hs - compiler/GHC/Cmm/MachOp.hs - compiler/GHC/Cmm/Parser.y - compiler/GHC/CmmToAsm/AArch64/CodeGen.hs - compiler/GHC/CmmToAsm/AArch64/Instr.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Data/BooleanFormula.hs - compiler/GHC/Driver/Session/Units.hs - compiler/GHC/Hs.hs - compiler/GHC/Hs/Dump.hs - compiler/GHC/Hs/Utils.hs - compiler/GHC/Iface/Binary.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Annotation.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Parser/PostProcess/Haddock.hs - ghc/GHCi/UI.hs - hadrian/README.md - hadrian/doc/cross-compile.md - hadrian/doc/flavours.md - hadrian/doc/make.md - hadrian/doc/windows.md - hadrian/hadrian.cabal - hadrian/src/CommandLine.hs - hadrian/src/Flavour.hs - hadrian/src/Settings.hs - − hadrian/src/Settings/Flavours/Quickest.hs - libraries/base/base.cabal.in - libraries/base/changelog.md - + libraries/base/src/Data/RealFloat.hs - libraries/base/src/GHC/Conc.hs - libraries/ghc-internal/include/RtsIfaceSymbols.h - libraries/ghc-internal/src/GHC/Internal/Conc/IO.hs - libraries/ghc-internal/src/GHC/Internal/Event/Thread.hs - libraries/ghc-internal/src/GHC/Internal/STM.hs - rts/CloneStack.c - rts/HeapStackCheck.cmm - rts/IOManager.c - rts/IOManager.h - rts/IOManagerInternals.h - rts/Interpreter.c - rts/Messages.c - rts/Prelude.h - rts/PrimOps.cmm - rts/StgMiscClosures.cmm - rts/Threads.c - rts/Threads.h - rts/include/rts/RtsToHsIface.h - rts/include/rts/storage/Closures.h - rts/include/stg/MiscClosures.h - rts/linker/elf_reloc_riscv64.c - rts/posix/Poll.c - rts/posix/Poll.h - rts/posix/Select.c - testsuite/driver/perf_notes.py - testsuite/driver/testglobals.py - testsuite/tests/cmm/should_compile/Makefile - + testsuite/tests/cmm/should_compile/T27368-ppr-debug.stderr - − testsuite/tests/cmm/should_compile/T27368-ppr-debug.stdout - testsuite/tests/cmm/should_compile/all.T - + testsuite/tests/codeGen/should_run/T27430.hs - + testsuite/tests/codeGen/should_run/T27430.stdout - + testsuite/tests/codeGen/should_run/T27430_c.c - + testsuite/tests/codeGen/should_run/T27533.hs - + testsuite/tests/codeGen/should_run/T27533.stdout - + testsuite/tests/codeGen/should_run/T27533_cmm.cmm - + testsuite/tests/codeGen/should_run/T27537.hs - + testsuite/tests/codeGen/should_run/T27537.stdout - + testsuite/tests/codeGen/should_run/T27538.hs - + testsuite/tests/codeGen/should_run/T27538.stdout - testsuite/tests/codeGen/should_run/all.T - + testsuite/tests/concurrent/should_run/T27657a.hs - + testsuite/tests/concurrent/should_run/T27657a.stdout - + testsuite/tests/concurrent/should_run/T27657b.hs - + testsuite/tests/concurrent/should_run/T27657b.stdout - testsuite/tests/concurrent/should_run/all.T - testsuite/tests/ghc-api/exactprint/T22919.stderr - testsuite/tests/ghc-api/exactprint/Test20239.stderr - testsuite/tests/ghc-api/exactprint/ZeroWidthSemi.stderr - + testsuite/tests/ghci/prog-mhu007/Makefile - + testsuite/tests/ghci/prog-mhu007/a/A.hs - + testsuite/tests/ghci/prog-mhu007/all.T - + testsuite/tests/ghci/prog-mhu007/b/B.hs - + testsuite/tests/ghci/prog-mhu007/prog-mhu007.script - + testsuite/tests/ghci/prog-mhu007/prog-mhu007.stdout - + testsuite/tests/ghci/prog-mhu007/testpkg-bar/Bar.hs - + testsuite/tests/ghci/prog-mhu007/testpkg-bar/testpkg-bar.pkg - + testsuite/tests/ghci/prog-mhu007/testpkg-foo/Foo.hs - + testsuite/tests/ghci/prog-mhu007/testpkg-foo/testpkg-foo.pkg - + testsuite/tests/ghci/prog-mhu007/unitA - + testsuite/tests/ghci/prog-mhu007/unitB - testsuite/tests/haddock/should_compile_flag_haddock/T17544.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - testsuite/tests/haddock/should_compile_flag_haddock/T24221.stderr - testsuite/tests/interface-stability/base-exports.stdout - testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs - testsuite/tests/interface-stability/base-exports.stdout-mingw32 - testsuite/tests/module/mod185.stderr - testsuite/tests/parser/should_compile/DumpParsedAst.stderr - testsuite/tests/parser/should_compile/DumpParsedAstComments.stderr - testsuite/tests/parser/should_compile/DumpRenamedAst.stderr - testsuite/tests/parser/should_compile/DumpSemis.stderr - testsuite/tests/parser/should_compile/DumpTypecheckedAst.stderr - testsuite/tests/parser/should_compile/KindSigs.stderr - testsuite/tests/parser/should_compile/T14189.stderr - testsuite/tests/parser/should_compile/T15323.stderr - testsuite/tests/parser/should_compile/T20452.stderr - testsuite/tests/parser/should_compile/T20718.stderr - testsuite/tests/parser/should_compile/T20718b.stderr - testsuite/tests/parser/should_compile/T20846.stderr - testsuite/tests/parser/should_compile/T23315/T23315.stderr - testsuite/tests/perf/compiler/all.T - testsuite/tests/printer/AnnotationNoListTuplePuns.stdout - + testsuite/tests/printer/Haddock1.hs - testsuite/tests/printer/Makefile - testsuite/tests/printer/T18791.stderr - testsuite/tests/printer/Test20297.stdout - testsuite/tests/printer/Test24533.stdout - testsuite/tests/printer/all.T - + testsuite/tests/simd/should_run/T27565.hs - + testsuite/tests/simd/should_run/T27565.stdout - testsuite/tests/simd/should_run/all.T - + testsuite/tests/simplCore/should_run/T27705.hs - + testsuite/tests/simplCore/should_run/T27705.stdout - + testsuite/tests/simplCore/should_run/T27705_Inst.hs - testsuite/tests/simplCore/should_run/all.T - utils/check-exact/ExactPrint.hs - utils/check-exact/Main.hs - utils/check-exact/Parsers.hs - utils/check-exact/Transform.hs - utils/check-exact/Utils.hs - utils/deriveConstants/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/Target.hs - utils/haddock/haddock-api/src/Haddock/Types.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/31af093ad9edcb56dd1d6b913fd4672... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/31af093ad9edcb56dd1d6b913fd4672... You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications: https://gitlab.haskell.org/-/profile/notifications | Help: https://gitlab.haskell.org/help