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[Git][ghc/ghc][master] Make SpecContr rules fire a bit later
by Marge Bot (＠marge-bot) 13 Jan '26

13 Jan '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 20d7efec by Simon Peyton Jones at 2026-01-13T12:41:22-05:00 Make SpecContr rules fire a bit later See #26615 and Note [SpecConstr rule activation] - - - - - 18 changed files: - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/Core/Rules.hs - compiler/GHC/Core/Unfold/Make.hs - testsuite/tests/simplCore/should_compile/T14003.stderr - testsuite/tests/simplCore/should_compile/T19672.stderr - testsuite/tests/simplCore/should_compile/T21763.stderr - testsuite/tests/simplCore/should_compile/T21763a.stderr - + testsuite/tests/simplCore/should_compile/T26615.hs - + testsuite/tests/simplCore/should_compile/T26615.stderr - + testsuite/tests/simplCore/should_compile/T26615a.hs - testsuite/tests/simplCore/should_compile/T4908.stderr - testsuite/tests/simplCore/should_compile/all.T - testsuite/tests/simplCore/should_compile/spec-inline.stderr The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/20d7efec9f1cdf9184331b83d0ef88a… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/20d7efec9f1cdf9184331b83d0ef88a… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26746] Wibble
by Simon Peyton Jones (＠simonpj) 13 Jan '26

13 Jan '26

Simon Peyton Jones pushed to branch wip/T26746 at Glasgow Haskell Compiler / GHC Commits: aed32875 by Simon Peyton Jones at 2026-01-13T17:26:49+00:00 Wibble - - - - - 2 changed files: - compiler/GHC/Tc/Instance/Family.hs - compiler/GHC/Tc/Solver/Equality.hs Changes: ===================================== compiler/GHC/Tc/Instance/Family.hs ===================================== @@ -478,7 +478,8 @@ tcUnwrapNewtype_maybe :: FamInstEnvs -> Maybe (GlobalRdrElt, TcCoercion, Type) tcUnwrapNewtype_maybe faminsts rdr_env ty | Just (tc,tys) <- tcSplitTyConApp_maybe ty - = try_fam_unwrap tc tys + = firstJust (try_nt_unwrap tc tys) + (try_fam_unwrap tc tys) | otherwise = Nothing where @@ -490,7 +491,7 @@ tcUnwrapNewtype_maybe faminsts rdr_env ty , Just (gre, nt_co, ty') <- try_nt_unwrap tc' tys' = Just (gre, mkTransCo fam_co nt_co, ty') | otherwise - = try_nt_unwrap tc tys + = Nothing try_nt_unwrap tc tys | Just con <- newTyConDataCon_maybe tc ===================================== compiler/GHC/Tc/Solver/Equality.hs ===================================== @@ -356,13 +356,13 @@ can_eq_nc _rewritten _rdr_env _envs ev eq_rel ty1 _ ty2 _ -- See Note [Eager newtype decomposition] -- You might think that representational role would also be OK, but -- see Note [Even more eager newtype decomposition] - ok (ty1:tys1) (ty2:tys2) (r:rs) - | Phantom <- r = ok tys1 tys2 rs - | ty1 `tcEqType` ty2 = ok tys1 tys2 rs + ok (ty1:tys1) (ty2:tys2) rs + | Phantom : rs <- r = ok tys1 tys2 rs + | ty1 `tcEqType` ty2 = ok tys1 tys2 (drop 1 rs) | otherwise = False ok [] [] _ = True - ok _ _ [] = False -- Oversaturated TyCon - ok _ _ _ = pprPanic "can_eq_nc:mismatch" (ppr ty1 $$ ppr ty2) + ok _ _ _ = False -- Mis-matched lengths, just about possible because of + -- kind polymorphism. Anyway False is a safe result! -- Unwrap newtypes, when in ReprEq only -- See Note [Solving newtype equalities: overview] @@ -1223,7 +1223,7 @@ There are three ways in which decomposing [W] (N ty1) ~r (N ty2) could be incomp instance (a~Bool) => C [a] [W] g3 :: C [alpha] When we get around to solving `g3` we'll discover (g2:alpha~Bool) - So that's a real infelity in the solver. + So that's a real infelicity in the solver. * Incompleteness example (EX4): check available Givens newtype Nt a = Mk Bool -- NB: a is not used in the RHS, View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/aed328751ad7389de62660d30d1573c… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/aed328751ad7389de62660d30d1573c… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26722] 19 commits: ghc-internal: Move STM utilities out of GHC.Internal.Conc.Sync
by Simon Peyton Jones (＠simonpj) 13 Jan '26

13 Jan '26

Simon Peyton Jones pushed to branch wip/T26722 at Glasgow Haskell Compiler / GHC Commits: 039bac4c by Ben Gamari at 2026-01-09T20:22:16-05:00 ghc-internal: Move STM utilities out of GHC.Internal.Conc.Sync This is necessary to avoid an import cycle on Windows when importing `GHC.Internal.Exception.Context` in `GHC.Internal.Conc.Sync`. On the road to address #25365. - - - - - 8c389e8c by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Capture backtrace from throwSTM Implements core-libraries-committee#297. Fixes #25365. - - - - - e1ce1fc3 by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Annotate rethrown exceptions in catchSTM with WhileHandling Implements core-libraries-committee#298 - - - - - c4ebdbdf by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: make getPrim eagerly evaluate its result This commit makes `GHC.Utils.Binary.getPrim` eagerly evaluate its result, to avoid accidental laziness when future patches build other binary parsers using `getPrim`. - - - - - 66a0c4f7 by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: implement fast get/put for Word16/Word32/Word64 Previously, `GHC.Utils.Binary` contains `get`/`put` functions for `Word16`/`Word32`/`Word64` which always loads and stores them as big-endian words at a potentially unaligned address. The previous implementation is based on loads/stores of individual bytes and concatenating bytes with bitwise operations, which currently cannot be fused to a single load/store operation by GHC. This patch implements fast `get`/`put` functions for `Word16`/`Word32`/`Word64` based on a single memory load/store, with an additional `byteSwap` operation on little-endian hosts. It is based on unaligned load/store primops added since GHC 9.10, and we already require booting with at least 9.10, so it's about time to switch to this faster path. - - - - - 641ec3f0 by Simon Peyton Jones at 2026-01-09T20:23:55-05:00 Fix scoping errors in specialisation Using -fspecialise-aggressively in #26682 showed up a couple of subtle errors in the type-class specialiser. * dumpBindUDs failed to call `deleteCallsMentioning`, resulting in a call that mentioned a dictionary that was not in scope. This call has been missing since 2009! commit c43c981705ec33da92a9ce91eb90f2ecf00be9fe Author: Simon Peyton Jones <simonpj(a)microsoft.com> Date: Fri Oct 23 16:15:51 2009 +0000 Fixed by re-combining `dumpBindUDs` and `dumpUDs`. * I think there was another bug involving the quantified type variables in polymorphic specialisation. In any case I refactored `specHeader` and `spec_call` so that the former looks for the extra quantified type variables rather than the latter. This is quite a worthwhile simplification: less code, easier to grok. Test case in simplCore/should_compile/T26682, brilliantly minimised by @sheaf. - - - - - 2433e91d by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change sectionProtection to take SectionType argument This commit changes `sectionProtection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. - - - - - e5926fbe by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change isInitOrFiniSection to take SectionType argument This commit changes `isInitOrFiniSection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. Also marks it as exported. - - - - - 244d57d7 by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: fix split sections on windows This patch fixes split sections on windows by emitting the right COMDAT section header in NCG, see added comment for more explanation. Fix #26696 #26494. ------------------------- Metric Decrease: LargeRecord T9675 size_hello_artifact size_hello_artifact_gzip size_hello_unicode size_hello_unicode_gzip Metric Increase: T13035 ------------------------- Co-authored-by: Codex <codex(a)openai.com> - - - - - 182f3d0f by Cheng Shao at 2026-01-09T20:25:28-05:00 iserv: add comment about -fkeep-cafs - - - - - 49675b69 by Matthew Craven at 2026-01-09T20:26:14-05:00 Account for "stupid theta" in demand sig for DataCon wrappers Fixes #26748. - - - - - f3c18890 by Samuel Thibault at 2026-01-10T15:48:22+01:00 hurd: Fix getExecutablePath build 3939a8bf93e27 ("GNU/Hurd: Add getExecutablePath support") added using /proc/self/exe for GNU/Hurd but missed adding the required imports for the corresponding code. - - - - - 7f15bd15 by Samuel Thibault at 2026-01-12T07:16:25-05:00 Fix the OS string encoding for GNU/Hurd Following https://github.com/haskell/cabal/pull/9434/files , and as seen in the various gnu_HOST_OS usages in the source code, it is expected that GNU/Hurd is advertised as "gnu", like the autotools do. - - - - - 1db2f240 by Andrew Lelechenko at 2026-01-12T07:17:06-05:00 Add since annotation for Data.Bifoldable1 Fixes #26432 - - - - - e038a383 by Sven Tennie at 2026-01-12T07:17:49-05:00 Ignore Windows CI tool directories in Git Otherwise, we see thousands of changes in `git status` which is very confusing to work with. - - - - - 023c301c by sheaf at 2026-01-13T04:57:30-05:00 Don't re-use stack slots for growing registers This commit avoids re-using a stack slot for a register that has grown but already had a stack slot. For example, suppose we have stack slot assigments %v1 :: FF64 |-> StackSlot 0 %v2 :: FF64 |-> StackSlot 1 Later, we start using %v1 at a larger format (e.g. F64x2) and we need to spill it again. Then we **must not** use StackSlot 0, as a spill at format F64x2 would clobber the data in StackSlot 1. This can cause some fragmentation of the `StackMap`, but that's probably OK. Fixes #26668 - - - - - d0966e64 by fendor at 2026-01-13T04:58:11-05:00 Remove `traceId` from ghc-pkg executable - - - - - dd5f833d by Simon Peyton Jones at 2026-01-13T16:45:00+00:00 Add evals for strict data-con args in worker-functions This fixes #26722, by adding an eval in a worker for arguments of strict data constructors, even if the function body uses them strictly. See (WIS1) in Note [Which Ids should be strictified] I took the opportunity to make substantial improvements in the documentation for call-by-value functions. See especially Note [CBV Function Ids: overview] in GHC.Types.Id.Info Note [Which Ids should be CBV candidates?] ditto Note [EPT enforcement] in GHC.Stg.EnforceEpt among others. - - - - - dc8001c2 by Simon Peyton Jones at 2026-01-13T16:45:00+00:00 Improve `interestingArg` This function analyses a function's argument to see if it is interesting enough to deserve an inlining discount. Improvements for * LitRubbish arguments * exprIsExpandable arguments See Note [Interesting arguments] which is substantially rewritten. - - - - - 59 changed files: - .gitignore - compiler/GHC/Cmm.hs - compiler/GHC/Cmm/InitFini.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/CmmToAsm/Ppr.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs - compiler/GHC/CmmToAsm/Wasm/FromCmm.hs - compiler/GHC/CmmToAsm/X86/Ppr.hs - compiler/GHC/CmmToC.hs - compiler/GHC/CmmToLlvm/Data.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/Core/Opt/WorkWrap/Utils.hs - compiler/GHC/Core/Tidy.hs - compiler/GHC/Core/Unfold.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/CoreToStg/Prep.hs - compiler/GHC/Stg/EnforceEpt.hs - compiler/GHC/Stg/Lint.hs - compiler/GHC/StgToCmm/Closure.hs - compiler/GHC/StgToCmm/Expr.hs - compiler/GHC/Types/Id.hs - compiler/GHC/Types/Id/Info.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Utils/Binary.hs - libraries/base/changelog.md - libraries/base/src/Data/Bifoldable1.hs - libraries/base/src/GHC/Conc.hs - libraries/base/src/GHC/Conc/Sync.hs - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/Conc/IO.hs - libraries/ghc-internal/src/GHC/Internal/Conc/POSIX.hs - libraries/ghc-internal/src/GHC/Internal/Conc/Sync.hs - libraries/ghc-internal/src/GHC/Internal/Conc/Sync.hs-boot - libraries/ghc-internal/src/GHC/Internal/Conc/Windows.hs - libraries/ghc-internal/src/GHC/Internal/Event/Thread.hs - libraries/ghc-internal/src/GHC/Internal/Event/Windows/Thread.hs - + libraries/ghc-internal/src/GHC/Internal/STM.hs - libraries/ghc-internal/src/GHC/Internal/System/Environment/ExecutablePath.hsc - libraries/ghc-platform/src/GHC/Platform/ArchOS.hs - + testsuite/tests/dmdanal/should_run/T26748.hs - + testsuite/tests/dmdanal/should_run/T26748.stdout - testsuite/tests/dmdanal/should_run/all.T - 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/interface-stability/base-exports.stdout-ws-32 - testsuite/tests/simplCore/should_compile/T18013.stderr - + testsuite/tests/simplCore/should_compile/T26682.hs - + testsuite/tests/simplCore/should_compile/T26682a.hs - + testsuite/tests/simplCore/should_compile/T26722.hs - + testsuite/tests/simplCore/should_compile/T26722.stderr - testsuite/tests/simplCore/should_compile/all.T - utils/ghc-pkg/Main.hs - utils/iserv/iserv.cabal.in The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/2a7e8721ec12ce5e1eab32a92f58f5… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/2a7e8721ec12ce5e1eab32a92f58f5… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26707] 45 commits: compiler: add targetHasRTSWays function
by Teo Camarasu (＠teo) 13 Jan '26

13 Jan '26

Teo Camarasu pushed to branch wip/T26707 at Glasgow Haskell Compiler / GHC Commits: 69e0ab59 by Cheng Shao at 2026-01-06T19:37:56-05:00 compiler: add targetHasRTSWays function This commit adds a `targetHasRTSWays` util function in `GHC.Driver.Session` to query if the target RTS has a given Ways (e.g. WayThreaded). - - - - - 25a0ab94 by Cheng Shao at 2026-01-06T19:37:56-05:00 compiler: link on-demand external interpreter with threaded RTS This commit makes the compiler link the on-demand external interpreter program with threaded RTS if it is available in the target RTS ways. This is a better default than the previous single-threaded RTS, and it enables the external interpreter to benefit from parallelism when deserializing CreateBCOs messages. - - - - - 92404a2b by Cheng Shao at 2026-01-06T19:37:56-05:00 hadrian: link iserv with threaded RTS This commit makes hadrian link iserv with threaded RTS if it's available in the RTS ways. Also cleans up the iserv main C program which can be replaced by the `-fkeep-cafs` link-time option. - - - - - a20542d2 by Cheng Shao at 2026-01-06T19:38:38-05:00 ghc-internal: remove unused GMP macros This patch removes unused GMP related macros from `ghc-internal`. The in-tree GMP version was hard coded and outdated, but it was not used anywhere anyway. - - - - - 4079dcd6 by Cheng Shao at 2026-01-06T19:38:38-05:00 hadrian: fix in-tree gmp configure error on newer c compilers Building in-tree gmp on newer c compilers that default to c23 fails at configure stage, this patch fixes it, see added comment for explanation. - - - - - 414d1fe1 by Cheng Shao at 2026-01-06T19:39:20-05:00 compiler: fix LLVM backend pdep/pext handling for i386 target This patch fixes LLVM backend's pdep/pext handling for i386 target, and also removes non-existent 128/256/512 bit hs_pdep/hs_pext callees. See amended note for more explanation. Fixes #26450. Co-authored-by: Codex <codex(a)openai.com> - - - - - c7f6fba3 by Cheng Shao at 2026-01-06T19:39:20-05:00 ci: remove allow_failure flag for i386 alpine job The LLVM codegen issue for i386 has been fixed, and the i386 alpine job should pass now. This commit removes the allow_failure flag so that other i386 regressions in the future are signaled more timely. - - - - - 52d00c05 by Simon Peyton Jones at 2026-01-07T10:24:21-05:00 Add missing InVar->OutVar lookup in SetLevels As #26681 showed, the SetLevels pass was failing to map an InVar to an OutVar. Very silly! I'm amazed it hasn't broken before now. I have improved the type singatures (to mention InVar and OutVar) so it's more obvious what needs to happen. - - - - - ab0a5594 by Cheng Shao at 2026-01-07T10:25:04-05:00 hadrian: drop deprecated pkgHashSplitObjs code path This patch drops deprecated `pkgHashSplitObjs` code path from hadrian, since GHC itself has removed split objs support many versions ago and this code path is unused. - - - - - bb3a2ba1 by Cheng Shao at 2026-01-07T10:25:44-05:00 hadrian: remove linting/assertion in quick-validate flavour The `quick-validate` flavour is meant for testing ghc and passing the testsuite locally with similar settings to `validate` but faster. This patch removes the linting/assertion overhead in `quick-validate` to improve developer experience. I also took the chance to simplify redundant logic of rts/library way definition in `validate` flavour. - - - - - 7971f5dd by Cheng Shao at 2026-01-07T10:26:26-05:00 deriveConstants: clean up unused constants This patch cleans up unused constants from `deriveConstants`, they are not used by C/Cmm code in the RTS, nor compiler-generated code. Co-authored-by: Codex <codex(a)openai.com> - - - - - 4df96993 by Cheng Shao at 2026-01-07T10:27:08-05:00 hadrian: pass -fno-omit-frame-pointer with +debug_info This patch adds `-fno-omit-frame-pointer` as C/C++ compilation flag when compiling with `+debug_info` flavour transformer. It's a sane default when you care about debugging and reliable backtraces, and makes debugging/profiling with bpf easier. - - - - - 8a3900a3 by Aaron Allen at 2026-01-07T10:27:57-05:00 [26705] Include TyCl instances in data fam iface entry Ensures dependent modules are recompiled when the class instances for a data family instance change. resolves #26705 - - - - - a0b980af by Cheng Shao at 2026-01-07T10:28:38-05:00 hadrian: remove unused Hp2Ps/Hpc builders This patch removes the Hp2Ps/Hpc builders from hadrian, they are unused in the build system. Note that the hp2ps/hpc programs are still built and not affected. - - - - - 50a58757 by Cheng Shao at 2026-01-07T10:29:20-05:00 hadrian: only install js files to libdir for wasm/js targets There are certain js files required for wasm/js targets to work, and previously hadrian would install those js files to libdir unconditionally on other targets as well. This could be a minor annoyance for packagers especially when the unused js files contain shebangs that interfere with the packaging process. This patch makes hadrian only selectively install the right js files for the right targets. Co-authored-by: Codex <codex(a)openai.com> - - - - - da40e553 by Simon Peyton Jones at 2026-01-07T10:30:00-05:00 Add flavour transformer assertions_stage1 This allows us to enable -DDEBUG assertions in the stage1 compiler - - - - - ec3cf767 by Cheng Shao at 2026-01-08T06:24:31-05:00 make: remove unused Makefiles from legacy make build system This patch removes unused Makefiles from legacy make build system; now they are never used by hadrian in any way, and they already include common boilerplate mk files that are long gone in the make build system removal, hence the housecleaning. Co-authored-by: Codex <codex(a)openai.com> - - - - - 04ea3f83 by Cheng Shao at 2026-01-08T06:25:13-05:00 compiler: use -O3 as LLVM optimization level for ghc -O2 The GHC driver clamps LLVM optimization level to `-O2` due to LLVM crashes, but those were historical issues many years ago that are no longer relevant for LLVM versions we support today. This patch changes the driver to use `-O3` as LLVM optimization level when compiling with `-O2`, which is a better default when we're willing to trade compilation time for faster generated code. - - - - - 472df471 by Peter Trommler at 2026-01-08T13:28:54-05:00 Use half-word literals in info tables With this commit info tables are mapped to the same assembler code on big-endian and little-endian platforms. Fixes #26579. - - - - - 393f9c51 by Simon Peyton Jones at 2026-01-08T13:29:35-05:00 Refactor srutOkForBinderSwap This MR does a small refactor: * Moves `scrutOkForBinderSwap` and `BinderSwapDecision` to GHC.Core.Utils * Inverts the sense of the coercion it returns, which makes more sense No effect on behaviour - - - - - ad76fb0f by Simon Peyton Jones at 2026-01-08T13:29:36-05:00 Improve case merging This small MR makes case merging happen a bit more often than it otherwise could, by getting join points out of the way. See #26709 and GHC.Core.Utils Note [Floating join points out of DEFAULT alternatives] - - - - - 4c9395f5 by Cheng Shao at 2026-01-08T13:30:16-05:00 hadrian: remove broken hsc2hs flag when cross compiling to windows This patch removes the `--via-asm` hsc2hs flag when cross compiling to windows. With recent llvm-mingw toolchain, it would fail with: ``` x86_64-w64-mingw32-hsc2hs: Cannot combine instructions: [Quad 8,Long 4,Long 241,Ref ".Ltmp1-.Ltmp0"] ``` The hsc2hs default `--cross-compile` logic is slower but works. - - - - - 71fdef55 by Simon Peyton Jones at 2026-01-08T13:30:57-05:00 Try harder to keep the substitution empty Avoid unnecessary cloning of variables in the Simplifier. Addresses #26724, See Note [Keeping the substitution empty] We get some big wins in compile time Metrics: compile_time/bytes allocated ------------------------------------- Baseline Test Metric value New value Change ---------------------------------------------------------------------------- CoOpt_Singletons(normal) ghc/alloc 721,544,088 692,174,216 -4.1% GOOD LargeRecord(normal) ghc/alloc 1,268,031,157 1,265,168,448 -0.2% T14766(normal) ghc/alloc 918,218,533 688,432,296 -25.0% GOOD T15703(normal) ghc/alloc 318,103,629 306,638,016 -3.6% GOOD T17836(normal) ghc/alloc 419,174,584 418,400,824 -0.2% T18478(normal) ghc/alloc 471,042,976 470,261,376 -0.2% T20261(normal) ghc/alloc 573,387,162 563,663,336 -1.7% T24984(normal) ghc/alloc 87,832,666 87,636,168 -0.2% T25196(optasm) ghc/alloc 1,103,284,040 1,101,376,992 -0.2% hard_hole_fits(normal) ghc/alloc 224,981,413 224,608,208 -0.2% geo. mean -0.3% minimum -25.0% maximum +0.1% Metric Decrease: CoOpt_Singletons T14766 T15703 - - - - - 30341168 by Simon Peyton Jones at 2026-01-08T13:31:38-05:00 Add regression test for #24867 - - - - - 1ac1a541 by Julian Ospald at 2026-01-09T02:48:53-05:00 Support statically linking executables properly Fixes #26434 In detail, this does a number of things: * Makes GHC aware of 'extra-libraries-static' (this changes the package database format). * Adds a switch '-static-external' that will honour 'extra-libraries-static' to link external system dependencies statically. * Adds a new field to settings/targets: "ld supports verbatim namespace". This field is used by '-static-external' to conditionally use '-l:foo.a' syntax during linking, which is more robust than trying to find the absolute path to an archive on our own. * Adds a switch '-fully-static' that is meant as a high-level interface for e.g. cabal. This also honours 'extra-libraries-static'. This also attempts to clean up the confusion around library search directories. At the moment, we have 3 types of directories in the package database format: * library-dirs * library-dirs-static * dynamic-library-dirs However, we only have two types of linking: dynamic or static. Given the existing logic in 'mungeDynLibFields', this patch assumes that 'library-dirs' is really just nothing but a fallback and always prefers the more specific variants if they exist and are non-empty. Conceptually, we should be ok with even just one search dirs variant. Haskell libraries are named differently depending on whether they're static or dynamic, so GHC can conveniently pick the right one depending on the linking needs. That means we don't really need to play tricks with search paths to convince the compiler to do linking as we want it. For system C libraries, the convention has been anyway to place static and dynamic libs next to each other, so we need to deal with that issue anyway and it is outside of our control. But this is out of the scope of this patch. This patch is backwards compatible with cabal. Cabal should however be patched to use the new '-fully-static' switch. - - - - - ad3c808d by Julian Ospald at 2026-01-09T02:48:53-05:00 Warn when "-dynamic" is mixed with "-staticlib" - - - - - 322dd672 by Matthew Pickering at 2026-01-09T02:49:35-05:00 rts: Use INFO_TABLE_CONSTR for stg_dummy_ret_closure Since the closure type is CONSTR_NOCAF, we need to use INFO_TABLE_CONSTR to populate the constructor description field (this crashes ghc-debug when decoding AP_STACK frames sometimes) Fixes #26745 - - - - - 039bac4c by Ben Gamari at 2026-01-09T20:22:16-05:00 ghc-internal: Move STM utilities out of GHC.Internal.Conc.Sync This is necessary to avoid an import cycle on Windows when importing `GHC.Internal.Exception.Context` in `GHC.Internal.Conc.Sync`. On the road to address #25365. - - - - - 8c389e8c by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Capture backtrace from throwSTM Implements core-libraries-committee#297. Fixes #25365. - - - - - e1ce1fc3 by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Annotate rethrown exceptions in catchSTM with WhileHandling Implements core-libraries-committee#298 - - - - - c4ebdbdf by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: make getPrim eagerly evaluate its result This commit makes `GHC.Utils.Binary.getPrim` eagerly evaluate its result, to avoid accidental laziness when future patches build other binary parsers using `getPrim`. - - - - - 66a0c4f7 by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: implement fast get/put for Word16/Word32/Word64 Previously, `GHC.Utils.Binary` contains `get`/`put` functions for `Word16`/`Word32`/`Word64` which always loads and stores them as big-endian words at a potentially unaligned address. The previous implementation is based on loads/stores of individual bytes and concatenating bytes with bitwise operations, which currently cannot be fused to a single load/store operation by GHC. This patch implements fast `get`/`put` functions for `Word16`/`Word32`/`Word64` based on a single memory load/store, with an additional `byteSwap` operation on little-endian hosts. It is based on unaligned load/store primops added since GHC 9.10, and we already require booting with at least 9.10, so it's about time to switch to this faster path. - - - - - 641ec3f0 by Simon Peyton Jones at 2026-01-09T20:23:55-05:00 Fix scoping errors in specialisation Using -fspecialise-aggressively in #26682 showed up a couple of subtle errors in the type-class specialiser. * dumpBindUDs failed to call `deleteCallsMentioning`, resulting in a call that mentioned a dictionary that was not in scope. This call has been missing since 2009! commit c43c981705ec33da92a9ce91eb90f2ecf00be9fe Author: Simon Peyton Jones <simonpj(a)microsoft.com> Date: Fri Oct 23 16:15:51 2009 +0000 Fixed by re-combining `dumpBindUDs` and `dumpUDs`. * I think there was another bug involving the quantified type variables in polymorphic specialisation. In any case I refactored `specHeader` and `spec_call` so that the former looks for the extra quantified type variables rather than the latter. This is quite a worthwhile simplification: less code, easier to grok. Test case in simplCore/should_compile/T26682, brilliantly minimised by @sheaf. - - - - - 2433e91d by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change sectionProtection to take SectionType argument This commit changes `sectionProtection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. - - - - - e5926fbe by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change isInitOrFiniSection to take SectionType argument This commit changes `isInitOrFiniSection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. Also marks it as exported. - - - - - 244d57d7 by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: fix split sections on windows This patch fixes split sections on windows by emitting the right COMDAT section header in NCG, see added comment for more explanation. Fix #26696 #26494. ------------------------- Metric Decrease: LargeRecord T9675 size_hello_artifact size_hello_artifact_gzip size_hello_unicode size_hello_unicode_gzip Metric Increase: T13035 ------------------------- Co-authored-by: Codex <codex(a)openai.com> - - - - - 182f3d0f by Cheng Shao at 2026-01-09T20:25:28-05:00 iserv: add comment about -fkeep-cafs - - - - - 49675b69 by Matthew Craven at 2026-01-09T20:26:14-05:00 Account for "stupid theta" in demand sig for DataCon wrappers Fixes #26748. - - - - - f3c18890 by Samuel Thibault at 2026-01-10T15:48:22+01:00 hurd: Fix getExecutablePath build 3939a8bf93e27 ("GNU/Hurd: Add getExecutablePath support") added using /proc/self/exe for GNU/Hurd but missed adding the required imports for the corresponding code. - - - - - 7f15bd15 by Samuel Thibault at 2026-01-12T07:16:25-05:00 Fix the OS string encoding for GNU/Hurd Following https://github.com/haskell/cabal/pull/9434/files , and as seen in the various gnu_HOST_OS usages in the source code, it is expected that GNU/Hurd is advertised as "gnu", like the autotools do. - - - - - 1db2f240 by Andrew Lelechenko at 2026-01-12T07:17:06-05:00 Add since annotation for Data.Bifoldable1 Fixes #26432 - - - - - e038a383 by Sven Tennie at 2026-01-12T07:17:49-05:00 Ignore Windows CI tool directories in Git Otherwise, we see thousands of changes in `git status` which is very confusing to work with. - - - - - 023c301c by sheaf at 2026-01-13T04:57:30-05:00 Don't re-use stack slots for growing registers This commit avoids re-using a stack slot for a register that has grown but already had a stack slot. For example, suppose we have stack slot assigments %v1 :: FF64 |-> StackSlot 0 %v2 :: FF64 |-> StackSlot 1 Later, we start using %v1 at a larger format (e.g. F64x2) and we need to spill it again. Then we **must not** use StackSlot 0, as a spill at format F64x2 would clobber the data in StackSlot 1. This can cause some fragmentation of the `StackMap`, but that's probably OK. Fixes #26668 - - - - - d0966e64 by fendor at 2026-01-13T04:58:11-05:00 Remove `traceId` from ghc-pkg executable - - - - - 44c3d591 by Teo Camarasu at 2026-01-13T15:09:31+00:00 Set default eventlog-flush-interval to 5s Resolves #26707 - - - - - 154 changed files: - .gitignore - .gitlab/generate-ci/gen_ci.hs - .gitlab/jobs.yaml - compiler/GHC.hs - compiler/GHC/Cmm.hs - compiler/GHC/Cmm/Info.hs - compiler/GHC/Cmm/InitFini.hs - compiler/GHC/Cmm/Utils.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/CmmToAsm/Ppr.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs - compiler/GHC/CmmToAsm/Wasm/FromCmm.hs - compiler/GHC/CmmToAsm/X86/Ppr.hs - compiler/GHC/CmmToC.hs - compiler/GHC/CmmToLlvm/CodeGen.hs - compiler/GHC/CmmToLlvm/Data.hs - compiler/GHC/Core/Opt/OccurAnal.hs - compiler/GHC/Core/Opt/SetLevels.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Subst.hs - compiler/GHC/Core/TyCo/Subst.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/Driver/Backpack.hs - compiler/GHC/Driver/Config/Interpreter.hs - compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/Pipeline.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Iface/Recomp.hs - compiler/GHC/Linker/Dynamic.hs - compiler/GHC/Linker/Executable.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Linker/Unit.hs - compiler/GHC/Runtime/Interpreter/C.hs - compiler/GHC/Runtime/Interpreter/Init.hs - compiler/GHC/Settings.hs - compiler/GHC/Settings/IO.hs - compiler/GHC/StgToJS/Linker/Utils.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Unit/Info.hs - compiler/GHC/Unit/State.hs - compiler/GHC/Utils/Binary.hs - configure.ac - distrib/configure.ac.in - − docs/Makefile - − docs/storage-mgt/Makefile - docs/users_guide/9.16.1-notes.rst - − docs/users_guide/Makefile - docs/users_guide/phases.rst - − driver/Makefile - − driver/ghc/Makefile - − driver/ghci/Makefile - − driver/haddock/Makefile - ghc/Main.hs - − ghc/Makefile - hadrian/cfg/default.host.target.in - hadrian/cfg/default.target.in - hadrian/doc/flavours.md - hadrian/src/Base.hs - hadrian/src/Builder.hs - hadrian/src/Flavour.hs - hadrian/src/Hadrian/Haskell/Hash.hs - hadrian/src/Oracles/Setting.hs - hadrian/src/Packages.hs - hadrian/src/Rules/Gmp.hs - hadrian/src/Rules/Register.hs - hadrian/src/Settings/Builders/Cabal.hs - hadrian/src/Settings/Builders/Hsc2Hs.hs - hadrian/src/Settings/Flavours/Validate.hs - hadrian/src/Settings/Packages.hs - − libraries/Makefile - libraries/base/changelog.md - libraries/base/src/Data/Bifoldable1.hs - libraries/base/src/GHC/Conc.hs - libraries/base/src/GHC/Conc/Sync.hs - − libraries/doc/Makefile - libraries/ghc-boot/GHC/Unit/Database.hs - libraries/ghc-internal/configure.ac - libraries/ghc-internal/ghc-internal.buildinfo.in - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/include/HsIntegerGmp.h.in - libraries/ghc-internal/src/GHC/Internal/Conc/IO.hs - libraries/ghc-internal/src/GHC/Internal/Conc/POSIX.hs - libraries/ghc-internal/src/GHC/Internal/Conc/Sync.hs - libraries/ghc-internal/src/GHC/Internal/Conc/Sync.hs-boot - libraries/ghc-internal/src/GHC/Internal/Conc/Windows.hs - libraries/ghc-internal/src/GHC/Internal/Event/Thread.hs - libraries/ghc-internal/src/GHC/Internal/Event/Windows/Thread.hs - + libraries/ghc-internal/src/GHC/Internal/STM.hs - libraries/ghc-internal/src/GHC/Internal/System/Environment/ExecutablePath.hsc - libraries/ghc-platform/src/GHC/Platform/ArchOS.hs - − linters/lint-codes/Makefile - − linters/lint-notes/Makefile - llvm-passes - + m4/fp_linker_supports_verbatim.m4 - m4/prep_target_file.m4 - mk/system-cxx-std-lib-1.0.conf.in - − rts/Makefile - rts/RtsFlags.c - rts/StgMiscClosures.cmm - rts/configure.ac - − rts/include/Makefile - rts/rts.buildinfo.in - rts/rts.cabal - + testsuite/driver/_elffile.py - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/ghc-config/ghc-config.hs - + testsuite/tests/dmdanal/should_run/T26748.hs - + testsuite/tests/dmdanal/should_run/T26748.stdout - testsuite/tests/dmdanal/should_run/all.T - + testsuite/tests/driver/fully-static/Hello.hs - + testsuite/tests/driver/fully-static/Makefile - + testsuite/tests/driver/fully-static/all.T - + testsuite/tests/driver/fully-static/fully-static.stdout - + testsuite/tests/driver/fully-static/test/Test.hs - + testsuite/tests/driver/fully-static/test/test.pkg - + testsuite/tests/driver/mostly-static/Hello.hs - + testsuite/tests/driver/mostly-static/Makefile - + testsuite/tests/driver/mostly-static/all.T - + testsuite/tests/driver/mostly-static/mostly-static.stdout - + testsuite/tests/driver/mostly-static/test/test.c - + testsuite/tests/driver/mostly-static/test/test.h - + testsuite/tests/driver/mostly-static/test/test.pkg - + testsuite/tests/driver/recomp26705/M.hs - + testsuite/tests/driver/recomp26705/M2A.hs - + testsuite/tests/driver/recomp26705/M2B.hs - + testsuite/tests/driver/recomp26705/Makefile - + testsuite/tests/driver/recomp26705/all.T - + testsuite/tests/driver/recomp26705/recomp26705.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/interface-stability/base-exports.stdout-ws-32 - + testsuite/tests/pmcheck/should_compile/T24867.hs - + testsuite/tests/pmcheck/should_compile/T24867.stderr - testsuite/tests/pmcheck/should_compile/all.T - + testsuite/tests/simplCore/should_compile/T26681.hs - + testsuite/tests/simplCore/should_compile/T26682.hs - + testsuite/tests/simplCore/should_compile/T26682a.hs - + testsuite/tests/simplCore/should_compile/T26709.hs - + testsuite/tests/simplCore/should_compile/T26709.stderr - testsuite/tests/simplCore/should_compile/all.T - utils/deriveConstants/Main.hs - utils/ghc-pkg/Main.hs - utils/ghc-toolchain/exe/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/Tools/Link.hs - − utils/iserv/cbits/iservmain.c - utils/iserv/iserv.cabal.in The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ec0609104e086e0e20925a76619d19… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/ec0609104e086e0e20925a76619d19… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc] Pushed new branch wip/fix-windows-cross-llvm
by Cheng Shao (＠TerrorJack) 13 Jan '26

13 Jan '26

Cheng Shao pushed new branch wip/fix-windows-cross-llvm at Glasgow Haskell Compiler / GHC -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/tree/wip/fix-windows-cross-llvm You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26519] 3 commits: Don't re-use stack slots for growing registers
by Peter Trommler (＠trommler) 13 Jan '26

13 Jan '26

Peter Trommler pushed to branch wip/T26519 at Glasgow Haskell Compiler / GHC Commits: 023c301c by sheaf at 2026-01-13T04:57:30-05:00 Don't re-use stack slots for growing registers This commit avoids re-using a stack slot for a register that has grown but already had a stack slot. For example, suppose we have stack slot assigments %v1 :: FF64 |-> StackSlot 0 %v2 :: FF64 |-> StackSlot 1 Later, we start using %v1 at a larger format (e.g. F64x2) and we need to spill it again. Then we **must not** use StackSlot 0, as a spill at format F64x2 would clobber the data in StackSlot 1. This can cause some fragmentation of the `StackMap`, but that's probably OK. Fixes #26668 - - - - - d0966e64 by fendor at 2026-01-13T04:58:11-05:00 Remove `traceId` from ghc-pkg executable - - - - - b324fd55 by Peter Trommler at 2026-01-13T13:28:52+01:00 PPC NCG: Fix shift right MO code The shift amount in shift right [arithmetic] MOs is machine word width. Therefore remove unnecessary zero- or sign-extending of shift amount. It looks harmless to extend the shift amount argument because the shift right instruction uses only the seven lowest bits (i. e. mod 128). But now we have a conversion operation from a smaller type to word width around a memory load at word width. The types are not matching up but there is no check done in CodeGen. The necessary conversion from word width down to the smaller width would be translated into a no-op on PowerPC anyway. So all seems harmless if it was not for a small optimisation in getRegister'. In getRegister' a load instruction with the smaller width of the conversion operation was generated. This loaded the most significant bits of the word in memory on a big-endian platform. These bits were zero and hence shift right was used with shift amount zero and not one as required in test Sized. Fixes #26519 - - - - - 4 changed files: - compiler/GHC/CmmToAsm/PPC/CodeGen.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs - utils/ghc-pkg/Main.hs Changes: ===================================== compiler/GHC/CmmToAsm/PPC/CodeGen.hs ===================================== @@ -467,48 +467,26 @@ getRegister' _ platform (CmmLoad mem pk _) return (Any II64 code) -- catch simple cases of zero- or sign-extended load -getRegister' _ _ (CmmMachOp (MO_UU_Conv W8 W32) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II32 (\dst -> addr_code `snocOL` LD II8 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_XX_Conv W8 W32) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II32 (\dst -> addr_code `snocOL` LD II8 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_UU_Conv W8 W64) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II64 (\dst -> addr_code `snocOL` LD II8 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_XX_Conv W8 W64) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II64 (\dst -> addr_code `snocOL` LD II8 dst addr)) - --- Note: there is no Load Byte Arithmetic instruction, so no signed case here - -getRegister' _ _ (CmmMachOp (MO_UU_Conv W16 W32) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II32 (\dst -> addr_code `snocOL` LD II16 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_SS_Conv W16 W32) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II32 (\dst -> addr_code `snocOL` LA II16 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_UU_Conv W16 W64) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II64 (\dst -> addr_code `snocOL` LD II16 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_SS_Conv W16 W64) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II64 (\dst -> addr_code `snocOL` LA II16 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_UU_Conv W32 W64) [CmmLoad mem _ _]) = do - Amode addr addr_code <- getAmode D mem - return (Any II64 (\dst -> addr_code `snocOL` LD II32 dst addr)) - -getRegister' _ _ (CmmMachOp (MO_SS_Conv W32 W64) [CmmLoad mem _ _]) = do - -- lwa is DS-form. See Note [Power instruction format] - Amode addr addr_code <- getAmode DS mem - return (Any II64 (\dst -> addr_code `snocOL` LA II32 dst addr)) +getRegister' _ _ (CmmMachOp (MO_UU_Conv src tgt) [CmmLoad mem pk _]) + | src < tgt + , cmmTypeFormat pk == intFormat src = loadZeroExpand mem pk tgt + +getRegister' _ _ (CmmMachOp (MO_XX_Conv src tgt) [CmmLoad mem pk _]) + | src < tgt + , cmmTypeFormat pk == intFormat src = loadZeroExpand mem pk tgt + + -- XXX: This is ugly, refactor +getRegister' _ _ (CmmMachOp (MO_SS_Conv src tgt) [CmmLoad mem pk _]) + -- Note: there is no Load Byte Arithmetic instruction + | cmmTypeFormat pk /= II8 + , src < tgt = do + let format = cmmTypeFormat pk + -- lwa is DS-form. See Note [Power instruction format] + let form = if format >= II32 then DS else D + Amode addr addr_code <- getAmode form mem + let code dst = assert (format == intFormat src) + $ addr_code `snocOL` LA format dst addr + return (Any (intFormat tgt) code) getRegister' config platform (CmmMachOp (MO_RelaxedRead w) [e]) = getRegister' config platform (CmmLoad e (cmmBits w) NaturallyAligned) @@ -789,6 +767,12 @@ extendSExpr from to x = CmmMachOp (MO_SS_Conv from to) [x] extendUExpr :: Width -> Width -> CmmExpr -> CmmExpr extendUExpr from to x = CmmMachOp (MO_UU_Conv from to) [x] +loadZeroExpand :: CmmExpr -> CmmType -> Width -> NatM Register +loadZeroExpand mem pk tgt = do + Amode addr addr_code <- getAmode D mem + let code dst = addr_code `snocOL` LD (cmmTypeFormat pk) dst addr + return (Any (intFormat tgt) code) + -- ----------------------------------------------------------------------------- -- The 'Amode' type: Memory addressing modes passed up the tree. @@ -2448,8 +2432,8 @@ srCode width sgn instr x y = do let op_len = max W32 width extend = if sgn then extendSExpr else extendUExpr (src1, code1) <- getSomeReg (extend width op_len x) - (src2, code2) <- getSomeReg (extendUExpr width op_len y) - -- Note: Shift amount `y` is unsigned + (src2, code2) <- getSomeReg y + let code dst = code1 `appOL` code2 `snocOL` instr (intFormat op_len) dst src1 (RIReg src2) return (Any (intFormat width) code) ===================================== compiler/GHC/CmmToAsm/Reg/Linear.hs ===================================== @@ -406,7 +406,7 @@ linearRA block_live block_id = go [] [] -- | Do allocation for a single instruction. raInsn :: OutputableRegConstraint freeRegs instr - => BlockMap Regs -- ^ map of what vregs are love on entry to each block. + => BlockMap Regs -- ^ map of what vregs are live on entry to each block. -> [instr] -- ^ accumulator for instructions already processed. -> BlockId -- ^ the id of the current block, for debugging -> LiveInstr instr -- ^ the instr to have its regs allocated, with liveness info. ===================================== compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs ===================================== @@ -37,7 +37,11 @@ data StackMap -- See Note [UniqFM and the register allocator] -- | Assignment of vregs to stack slots. - , stackMapAssignment :: UniqFM Unique StackSlot } + -- + -- We record not just the slot, but also how many stack slots the vreg + -- takes up, in order to avoid re-using a stack slot for a register + -- that has grown but already had a stack slot (#26668). + , stackMapAssignment :: UniqFM Unique (StackSlot, Int) } -- | An empty stack map, with all slots available. @@ -50,14 +54,19 @@ emptyStackMap = StackMap 0 emptyUFM -- getStackSlotFor :: StackMap -> Format -> Unique -> (StackMap, Int) -getStackSlotFor fs@(StackMap _ reserved) _fmt regUnique - | Just slot <- lookupUFM reserved regUnique = (fs, slot) - -getStackSlotFor (StackMap freeSlot reserved) fmt regUnique = - let - nbSlots = (formatInBytes fmt + 7) `div` 8 - in - (StackMap (freeSlot+nbSlots) (addToUFM reserved regUnique freeSlot), freeSlot) +getStackSlotFor fs@(StackMap freeSlot reserved) fmt regUnique + -- The register already has a stack slot; try to re-use it. + | Just (slot, nbSlots) <- lookupUFM reserved regUnique + -- Make sure the slot is big enough for this format, in case the register + -- has grown (#26668). + , nbNeededSlots <= nbSlots + = (fs, slot) + | otherwise + = (StackMap (freeSlot+nbNeededSlots) (addToUFM reserved regUnique (freeSlot, nbNeededSlots)), freeSlot) + -- NB: this can create fragmentation if a register keeps growing. + -- That's probably OK, as this is only happens very rarely. + where + !nbNeededSlots = (formatInBytes fmt + 7) `div` 8 -- | Return the number of stack slots that were allocated getStackUse :: StackMap -> Int ===================================== utils/ghc-pkg/Main.hs ===================================== @@ -23,7 +23,6 @@ module Main (main) where -import Debug.Trace import qualified GHC.Unit.Database as GhcPkg import GHC.Unit.Database hiding (mkMungePathUrl) import GHC.HandleEncoding @@ -1634,7 +1633,7 @@ listPackages verbosity my_flags mPackageName mModuleName = do simplePackageList :: [Flag] -> [InstalledPackageInfo] -> IO () simplePackageList my_flags pkgs = do let showPkg :: InstalledPackageInfo -> String - showPkg | FlagShowUnitIds `elem` my_flags = traceId . display . installedUnitId + showPkg | FlagShowUnitIds `elem` my_flags = display . installedUnitId | FlagNamesOnly `elem` my_flags = display . mungedName . mungedId | otherwise = display . mungedId strs = map showPkg pkgs View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/b79c71f3b6b88c22cb75c1437b0734… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/b79c71f3b6b88c22cb75c1437b0734… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 5 commits: Don't re-use stack slots for growing registers
by Marge Bot (＠marge-bot) 13 Jan '26

13 Jan '26

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: 023c301c by sheaf at 2026-01-13T04:57:30-05:00 Don't re-use stack slots for growing registers This commit avoids re-using a stack slot for a register that has grown but already had a stack slot. For example, suppose we have stack slot assigments %v1 :: FF64 |-> StackSlot 0 %v2 :: FF64 |-> StackSlot 1 Later, we start using %v1 at a larger format (e.g. F64x2) and we need to spill it again. Then we **must not** use StackSlot 0, as a spill at format F64x2 would clobber the data in StackSlot 1. This can cause some fragmentation of the `StackMap`, but that's probably OK. Fixes #26668 - - - - - d0966e64 by fendor at 2026-01-13T04:58:11-05:00 Remove `traceId` from ghc-pkg executable - - - - - 64fcc203 by Simon Peyton Jones at 2026-01-13T05:30:55-05:00 Make SpecContr rules fire a bit later See #26615 and Note [SpecConstr rule activation] - - - - - 964ec5e2 by Andrew Lelechenko at 2026-01-13T05:30:56-05:00 Upgrade mtl submodule to 2.3.2 Fixes #26656 - - - - - d00f9a3b by Cheng Shao at 2026-01-13T05:30:57-05:00 compiler: remove iserv and only use on-demand external interpreter This patch removes `iserv` from the tree completely. Hadrian would no longer build or distribute `iserv`, and the GHC driver would use the on-demand external interpreter by default when invoked with `-fexternal-interpreter`, without needing to specify `-pgmi ""`. This has multiple benefits: - It allows cleanup of a lot of legacy hacks in the hadrian codebase. - It paves the way for running cross ghc's iserv via cross emulator (#25523), fixing TH/ghci support for cross targets other than wasm/js. - - - - - 42 changed files: - CODEOWNERS - cabal.project-reinstall - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/Core/Rules.hs - compiler/GHC/Core/Unfold/Make.hs - compiler/GHC/Runtime/Interpreter/Init.hs - compiler/GHC/Settings/IO.hs - docs/users_guide/ghci.rst - docs/users_guide/phases.rst - hadrian/doc/user-settings.md - hadrian/src/Packages.hs - hadrian/src/Rules/BinaryDist.hs - hadrian/src/Rules/CabalReinstall.hs - hadrian/src/Rules/Generate.hs - hadrian/src/Rules/Program.hs - hadrian/src/Rules/Test.hs - hadrian/src/Settings/Builders/Ghc.hs - hadrian/src/Settings/Default.hs - hadrian/src/Settings/Packages.hs - libraries/mtl - − testsuite/tests/driver/T24731.hs - testsuite/tests/driver/all.T - testsuite/tests/simplCore/should_compile/T14003.stderr - testsuite/tests/simplCore/should_compile/T19672.stderr - testsuite/tests/simplCore/should_compile/T21763.stderr - testsuite/tests/simplCore/should_compile/T21763a.stderr - + testsuite/tests/simplCore/should_compile/T26615.hs - + testsuite/tests/simplCore/should_compile/T26615.stderr - + testsuite/tests/simplCore/should_compile/T26615a.hs - testsuite/tests/simplCore/should_compile/T4908.stderr - testsuite/tests/simplCore/should_compile/all.T - testsuite/tests/simplCore/should_compile/spec-inline.stderr - utils/ghc-pkg/Main.hs - − utils/iserv/iserv.cabal.in - − utils/iserv/src/Main.hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/9f61ac3b25daf86ca4e43312a38ec7… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/9f61ac3b25daf86ca4e43312a38ec7… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][wip/T26746] 19 commits: Support statically linking executables properly
by Simon Peyton Jones (＠simonpj) 13 Jan '26

13 Jan '26

Simon Peyton Jones pushed to branch wip/T26746 at Glasgow Haskell Compiler / GHC Commits: 1ac1a541 by Julian Ospald at 2026-01-09T02:48:53-05:00 Support statically linking executables properly Fixes #26434 In detail, this does a number of things: * Makes GHC aware of 'extra-libraries-static' (this changes the package database format). * Adds a switch '-static-external' that will honour 'extra-libraries-static' to link external system dependencies statically. * Adds a new field to settings/targets: "ld supports verbatim namespace". This field is used by '-static-external' to conditionally use '-l:foo.a' syntax during linking, which is more robust than trying to find the absolute path to an archive on our own. * Adds a switch '-fully-static' that is meant as a high-level interface for e.g. cabal. This also honours 'extra-libraries-static'. This also attempts to clean up the confusion around library search directories. At the moment, we have 3 types of directories in the package database format: * library-dirs * library-dirs-static * dynamic-library-dirs However, we only have two types of linking: dynamic or static. Given the existing logic in 'mungeDynLibFields', this patch assumes that 'library-dirs' is really just nothing but a fallback and always prefers the more specific variants if they exist and are non-empty. Conceptually, we should be ok with even just one search dirs variant. Haskell libraries are named differently depending on whether they're static or dynamic, so GHC can conveniently pick the right one depending on the linking needs. That means we don't really need to play tricks with search paths to convince the compiler to do linking as we want it. For system C libraries, the convention has been anyway to place static and dynamic libs next to each other, so we need to deal with that issue anyway and it is outside of our control. But this is out of the scope of this patch. This patch is backwards compatible with cabal. Cabal should however be patched to use the new '-fully-static' switch. - - - - - ad3c808d by Julian Ospald at 2026-01-09T02:48:53-05:00 Warn when "-dynamic" is mixed with "-staticlib" - - - - - 322dd672 by Matthew Pickering at 2026-01-09T02:49:35-05:00 rts: Use INFO_TABLE_CONSTR for stg_dummy_ret_closure Since the closure type is CONSTR_NOCAF, we need to use INFO_TABLE_CONSTR to populate the constructor description field (this crashes ghc-debug when decoding AP_STACK frames sometimes) Fixes #26745 - - - - - 039bac4c by Ben Gamari at 2026-01-09T20:22:16-05:00 ghc-internal: Move STM utilities out of GHC.Internal.Conc.Sync This is necessary to avoid an import cycle on Windows when importing `GHC.Internal.Exception.Context` in `GHC.Internal.Conc.Sync`. On the road to address #25365. - - - - - 8c389e8c by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Capture backtrace from throwSTM Implements core-libraries-committee#297. Fixes #25365. - - - - - e1ce1fc3 by Ben Gamari at 2026-01-09T20:22:16-05:00 base: Annotate rethrown exceptions in catchSTM with WhileHandling Implements core-libraries-committee#298 - - - - - c4ebdbdf by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: make getPrim eagerly evaluate its result This commit makes `GHC.Utils.Binary.getPrim` eagerly evaluate its result, to avoid accidental laziness when future patches build other binary parsers using `getPrim`. - - - - - 66a0c4f7 by Cheng Shao at 2026-01-09T20:23:06-05:00 compiler: implement fast get/put for Word16/Word32/Word64 Previously, `GHC.Utils.Binary` contains `get`/`put` functions for `Word16`/`Word32`/`Word64` which always loads and stores them as big-endian words at a potentially unaligned address. The previous implementation is based on loads/stores of individual bytes and concatenating bytes with bitwise operations, which currently cannot be fused to a single load/store operation by GHC. This patch implements fast `get`/`put` functions for `Word16`/`Word32`/`Word64` based on a single memory load/store, with an additional `byteSwap` operation on little-endian hosts. It is based on unaligned load/store primops added since GHC 9.10, and we already require booting with at least 9.10, so it's about time to switch to this faster path. - - - - - 641ec3f0 by Simon Peyton Jones at 2026-01-09T20:23:55-05:00 Fix scoping errors in specialisation Using -fspecialise-aggressively in #26682 showed up a couple of subtle errors in the type-class specialiser. * dumpBindUDs failed to call `deleteCallsMentioning`, resulting in a call that mentioned a dictionary that was not in scope. This call has been missing since 2009! commit c43c981705ec33da92a9ce91eb90f2ecf00be9fe Author: Simon Peyton Jones <simonpj(a)microsoft.com> Date: Fri Oct 23 16:15:51 2009 +0000 Fixed by re-combining `dumpBindUDs` and `dumpUDs`. * I think there was another bug involving the quantified type variables in polymorphic specialisation. In any case I refactored `specHeader` and `spec_call` so that the former looks for the extra quantified type variables rather than the latter. This is quite a worthwhile simplification: less code, easier to grok. Test case in simplCore/should_compile/T26682, brilliantly minimised by @sheaf. - - - - - 2433e91d by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change sectionProtection to take SectionType argument This commit changes `sectionProtection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. - - - - - e5926fbe by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: change isInitOrFiniSection to take SectionType argument This commit changes `isInitOrFiniSection` to only take `SectionType` argument instead of whole `Section`, since it doesn't need the Cmm section content anyway, and it can then be called in parts of NCG where we only have a `SectionType` in scope. Also marks it as exported. - - - - - 244d57d7 by Cheng Shao at 2026-01-09T20:24:43-05:00 compiler: fix split sections on windows This patch fixes split sections on windows by emitting the right COMDAT section header in NCG, see added comment for more explanation. Fix #26696 #26494. ------------------------- Metric Decrease: LargeRecord T9675 size_hello_artifact size_hello_artifact_gzip size_hello_unicode size_hello_unicode_gzip Metric Increase: T13035 ------------------------- Co-authored-by: Codex <codex(a)openai.com> - - - - - 182f3d0f by Cheng Shao at 2026-01-09T20:25:28-05:00 iserv: add comment about -fkeep-cafs - - - - - 49675b69 by Matthew Craven at 2026-01-09T20:26:14-05:00 Account for "stupid theta" in demand sig for DataCon wrappers Fixes #26748. - - - - - f3c18890 by Samuel Thibault at 2026-01-10T15:48:22+01:00 hurd: Fix getExecutablePath build 3939a8bf93e27 ("GNU/Hurd: Add getExecutablePath support") added using /proc/self/exe for GNU/Hurd but missed adding the required imports for the corresponding code. - - - - - 7f15bd15 by Samuel Thibault at 2026-01-12T07:16:25-05:00 Fix the OS string encoding for GNU/Hurd Following https://github.com/haskell/cabal/pull/9434/files , and as seen in the various gnu_HOST_OS usages in the source code, it is expected that GNU/Hurd is advertised as "gnu", like the autotools do. - - - - - 1db2f240 by Andrew Lelechenko at 2026-01-12T07:17:06-05:00 Add since annotation for Data.Bifoldable1 Fixes #26432 - - - - - e038a383 by Sven Tennie at 2026-01-12T07:17:49-05:00 Ignore Windows CI tool directories in Git Otherwise, we see thousands of changes in `git status` which is very confusing to work with. - - - - - 015523a3 by Simon Peyton Jones at 2026-01-13T10:30:29+00:00 Improve newtype unwrapping Ticket #26746 describes several relatively-minor shortcomings of newtype unwrapping. This MR addresses them, while also (arguably) simplifying the code a bit. See new Note [Solving newtype equalities: overview] and Note [Decomposing newtype equalities] and Note [Eager newtype decomposition] and Note [Even more eager newtype decomposition] - - - - - 104 changed files: - .gitignore - compiler/GHC/Cmm.hs - compiler/GHC/Cmm/InitFini.hs - compiler/GHC/CmmToAsm/AArch64/Ppr.hs - compiler/GHC/CmmToAsm/Ppr.hs - compiler/GHC/CmmToAsm/Wasm/FromCmm.hs - compiler/GHC/CmmToAsm/X86/Ppr.hs - compiler/GHC/CmmToC.hs - compiler/GHC/CmmToLlvm/Data.hs - compiler/GHC/Core/FamInstEnv.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Driver/Backpack.hs - compiler/GHC/Driver/Config/Interpreter.hs - compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/DynFlags.hs - compiler/GHC/Driver/Pipeline.hs - compiler/GHC/Driver/Session.hs - compiler/GHC/Linker/Dynamic.hs - compiler/GHC/Linker/Executable.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Linker/Unit.hs - compiler/GHC/Settings.hs - compiler/GHC/Settings/IO.hs - compiler/GHC/StgToJS/Linker/Utils.hs - compiler/GHC/Tc/Instance/Family.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Unit/Info.hs - compiler/GHC/Unit/State.hs - compiler/GHC/Utils/Binary.hs - configure.ac - distrib/configure.ac.in - docs/users_guide/phases.rst - ghc/Main.hs - hadrian/cfg/default.host.target.in - hadrian/cfg/default.target.in - hadrian/src/Settings/Builders/Cabal.hs - libraries/base/changelog.md - libraries/base/src/Data/Bifoldable1.hs - libraries/base/src/GHC/Conc.hs - libraries/base/src/GHC/Conc/Sync.hs - libraries/ghc-boot/GHC/Unit/Database.hs - libraries/ghc-internal/ghc-internal.buildinfo.in - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/src/GHC/Internal/Conc/IO.hs - libraries/ghc-internal/src/GHC/Internal/Conc/POSIX.hs - libraries/ghc-internal/src/GHC/Internal/Conc/Sync.hs - libraries/ghc-internal/src/GHC/Internal/Conc/Sync.hs-boot - libraries/ghc-internal/src/GHC/Internal/Conc/Windows.hs - libraries/ghc-internal/src/GHC/Internal/Event/Thread.hs - libraries/ghc-internal/src/GHC/Internal/Event/Windows/Thread.hs - + libraries/ghc-internal/src/GHC/Internal/STM.hs - libraries/ghc-internal/src/GHC/Internal/System/Environment/ExecutablePath.hsc - libraries/ghc-platform/src/GHC/Platform/ArchOS.hs - + m4/fp_linker_supports_verbatim.m4 - m4/prep_target_file.m4 - mk/system-cxx-std-lib-1.0.conf.in - rts/StgMiscClosures.cmm - rts/configure.ac - rts/rts.buildinfo.in - rts/rts.cabal - + testsuite/driver/_elffile.py - testsuite/driver/testglobals.py - testsuite/driver/testlib.py - testsuite/ghc-config/ghc-config.hs - testsuite/tests/deriving/should_fail/T8984.stderr - testsuite/tests/deriving/should_fail/deriving-via-fail.stderr - testsuite/tests/deriving/should_fail/deriving-via-fail4.stderr - testsuite/tests/deriving/should_fail/deriving-via-fail5.stderr - + testsuite/tests/dmdanal/should_run/T26748.hs - + testsuite/tests/dmdanal/should_run/T26748.stdout - testsuite/tests/dmdanal/should_run/all.T - + testsuite/tests/driver/fully-static/Hello.hs - + testsuite/tests/driver/fully-static/Makefile - + testsuite/tests/driver/fully-static/all.T - + testsuite/tests/driver/fully-static/fully-static.stdout - + testsuite/tests/driver/fully-static/test/Test.hs - + testsuite/tests/driver/fully-static/test/test.pkg - + testsuite/tests/driver/mostly-static/Hello.hs - + testsuite/tests/driver/mostly-static/Makefile - + testsuite/tests/driver/mostly-static/all.T - + testsuite/tests/driver/mostly-static/mostly-static.stdout - + testsuite/tests/driver/mostly-static/test/test.c - + testsuite/tests/driver/mostly-static/test/test.h - + testsuite/tests/driver/mostly-static/test/test.pkg - 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/interface-stability/base-exports.stdout-ws-32 - + testsuite/tests/simplCore/should_compile/T26682.hs - + testsuite/tests/simplCore/should_compile/T26682a.hs - testsuite/tests/simplCore/should_compile/all.T - + testsuite/tests/typecheck/should_compile/T26746.hs - testsuite/tests/typecheck/should_compile/all.T - testsuite/tests/typecheck/should_fail/T15801.stderr - testsuite/tests/typecheck/should_fail/T22924b.stderr - testsuite/tests/typecheck/should_fail/TcCoercibleFail.hs - testsuite/tests/typecheck/should_fail/TcCoercibleFail.stderr - testsuite/tests/typecheck/should_fail/all.T - utils/ghc-pkg/Main.hs - utils/ghc-toolchain/exe/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/Tools/Link.hs - utils/iserv/iserv.cabal.in The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/96c19504a9da2088d19701a5f12e49… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/96c19504a9da2088d19701a5f12e49… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] Remove `traceId` from ghc-pkg executable
by Marge Bot (＠marge-bot) 13 Jan '26

13 Jan '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: d0966e64 by fendor at 2026-01-13T04:58:11-05:00 Remove `traceId` from ghc-pkg executable - - - - - 1 changed file: - utils/ghc-pkg/Main.hs Changes: ===================================== utils/ghc-pkg/Main.hs ===================================== @@ -23,7 +23,6 @@ module Main (main) where -import Debug.Trace import qualified GHC.Unit.Database as GhcPkg import GHC.Unit.Database hiding (mkMungePathUrl) import GHC.HandleEncoding @@ -1634,7 +1633,7 @@ listPackages verbosity my_flags mPackageName mModuleName = do simplePackageList :: [Flag] -> [InstalledPackageInfo] -> IO () simplePackageList my_flags pkgs = do let showPkg :: InstalledPackageInfo -> String - showPkg | FlagShowUnitIds `elem` my_flags = traceId . display . installedUnitId + showPkg | FlagShowUnitIds `elem` my_flags = display . installedUnitId | FlagNamesOnly `elem` my_flags = display . mungedName . mungedId | otherwise = display . mungedId strs = map showPkg pkgs View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d0966e64880e9fa30ce07c0fa5ea281… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/d0966e64880e9fa30ce07c0fa5ea281… You're receiving this email because of your account on gitlab.haskell.org.

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[Git][ghc/ghc][master] Don't re-use stack slots for growing registers
by Marge Bot (＠marge-bot) 13 Jan '26

13 Jan '26

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC Commits: 023c301c by sheaf at 2026-01-13T04:57:30-05:00 Don't re-use stack slots for growing registers This commit avoids re-using a stack slot for a register that has grown but already had a stack slot. For example, suppose we have stack slot assigments %v1 :: FF64 |-> StackSlot 0 %v2 :: FF64 |-> StackSlot 1 Later, we start using %v1 at a larger format (e.g. F64x2) and we need to spill it again. Then we **must not** use StackSlot 0, as a spill at format F64x2 would clobber the data in StackSlot 1. This can cause some fragmentation of the `StackMap`, but that's probably OK. Fixes #26668 - - - - - 2 changed files: - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs Changes: ===================================== compiler/GHC/CmmToAsm/Reg/Linear.hs ===================================== @@ -406,7 +406,7 @@ linearRA block_live block_id = go [] [] -- | Do allocation for a single instruction. raInsn :: OutputableRegConstraint freeRegs instr - => BlockMap Regs -- ^ map of what vregs are love on entry to each block. + => BlockMap Regs -- ^ map of what vregs are live on entry to each block. -> [instr] -- ^ accumulator for instructions already processed. -> BlockId -- ^ the id of the current block, for debugging -> LiveInstr instr -- ^ the instr to have its regs allocated, with liveness info. ===================================== compiler/GHC/CmmToAsm/Reg/Linear/StackMap.hs ===================================== @@ -37,7 +37,11 @@ data StackMap -- See Note [UniqFM and the register allocator] -- | Assignment of vregs to stack slots. - , stackMapAssignment :: UniqFM Unique StackSlot } + -- + -- We record not just the slot, but also how many stack slots the vreg + -- takes up, in order to avoid re-using a stack slot for a register + -- that has grown but already had a stack slot (#26668). + , stackMapAssignment :: UniqFM Unique (StackSlot, Int) } -- | An empty stack map, with all slots available. @@ -50,14 +54,19 @@ emptyStackMap = StackMap 0 emptyUFM -- getStackSlotFor :: StackMap -> Format -> Unique -> (StackMap, Int) -getStackSlotFor fs@(StackMap _ reserved) _fmt regUnique - | Just slot <- lookupUFM reserved regUnique = (fs, slot) - -getStackSlotFor (StackMap freeSlot reserved) fmt regUnique = - let - nbSlots = (formatInBytes fmt + 7) `div` 8 - in - (StackMap (freeSlot+nbSlots) (addToUFM reserved regUnique freeSlot), freeSlot) +getStackSlotFor fs@(StackMap freeSlot reserved) fmt regUnique + -- The register already has a stack slot; try to re-use it. + | Just (slot, nbSlots) <- lookupUFM reserved regUnique + -- Make sure the slot is big enough for this format, in case the register + -- has grown (#26668). + , nbNeededSlots <= nbSlots + = (fs, slot) + | otherwise + = (StackMap (freeSlot+nbNeededSlots) (addToUFM reserved regUnique (freeSlot, nbNeededSlots)), freeSlot) + -- NB: this can create fragmentation if a register keeps growing. + -- That's probably OK, as this is only happens very rarely. + where + !nbNeededSlots = (formatInBytes fmt + 7) `div` 8 -- | Return the number of stack slots that were allocated getStackUse :: StackMap -> Int View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/023c301c51e7346af3d4d773c448277… -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/023c301c51e7346af3d4d773c448277… You're receiving this email because of your account on gitlab.haskell.org.

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