Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC Commits: fc207593 by sheaf at 2025-12-17T14:59:34-05:00 X86 CodeGen: fix assign_eax_sse_regs We must set %al to the number of SSE2 registers that contain arguments (in case we are dealing with a varargs function). The logic for counting how many arguments reside in SSE2 registers was incorrect, as it used 'isFloatFormat', which incorrectly ignores vector registers. We now instead do case analysis on the register class: is_sse_reg r = case targetClassOfReg platform r of RcFloatOrVector -> True RcInteger -> False This change is necessary to prevent segfaults in T20030_test1j, because subsequent commits change the format calculations, resulting in vector formats more often. - - - - - a430c6cf by sheaf at 2025-12-17T14:59:34-05:00 X86 regUsageOfInstr: fix format for IMUL When used with 8-bit operands, the IMUL instruction returns the result in the lower 16 bits of %rax (also known as %ax). This is different than for the other sizes, where an input at 16, 32 or 64 bits will result in 16, 32 or 64 bits of output in both %rax and %rdx. This doesn't affect the behaviour of the compiler, because we don't allow partial writes at sub-word sizes. The rationale is explained in Wrinkle [Don't allow scalar partial writes] in Note [Register formats in liveness analysis], in GHC.CmmToAsm.Reg.Liveness. - - - - - 0c801264 by sheaf at 2025-12-17T14:59:34-05:00 Liveness analysis: consider register formats This commit updates the register allocator to be a bit more careful in situations in which a single register is used at multiple different formats, e.g. when xmm1 is used both to store a Double# and a DoubleX2#. This is done by introducing the 'Regs' newtype around 'UniqSet RegWithFormat', for which the combining operations take the larger of the two formats instead of overriding the format. Operations on 'Regs' are defined in 'GHC.CmmToAsm.Reg.Regs'. There is a modest compile-time cost for the additional overhead for tracking register formats, which causes the metric increases of this commit. The subtle aspects of the implementation are outlined in Note [Register formats in liveness analysis] in GHC.CmmToAsm.Reg.Liveness. Fixes #26411 #26611 ------------------------- Metric Increase: T12707 T26425 T3294 ------------------------- - - - - - 1f1fc7f0 by sheaf at 2025-12-17T14:59:34-05:00 Register allocator: reload at same format as spill This commit ensures that if we spill a register onto the stack at a given format, we then always reload the register at this same format. This ensures we don't end up in a situation where we spill F64x2 but end up only reloading the lower F64. This first reload would make us believe the whole data is in a register, thus silently losing the upper 64 bits of the spilled register's contents. Fixes #26526 - - - - - b1a5dcc3 by sheaf at 2025-12-17T14:59:34-05:00 Register allocation: writes redefine format As explained in Note [Allocated register formats] in GHC.CmmToAsm.Reg.Linear, we consider all writes to redefine the format of the register. This ensures that in a situation such as movsd .Ln6m(%rip),%v1 shufpd $0,%v1,%v1 we properly consider the broadcast operation to change the format of %v1 from F64 to F64x2. This completes the fix to #26411 (test in T26411b). - - - - - 177d9a60 by Vladislav Zavialov at 2025-12-17T14:59:35-05:00 Parser: improve mkModuleImpExp, remove checkImportSpec 1. The `mkModuleImpExp` helper now knows whether it is processing an import or export list item, and uses this information to produce a more accurate error message for `import M (T(..,x))` with PatternSynonyms disabled. The old message incorrectly referred to this case as an export form. 2. The `checkImportSpec` helper is removed in favor of more comprehensive error checking in `mkModuleImpExp`. 3. Additionaly, the invariants of `ImpExpList` and `ImpExpAllWith` have been made more explicit in the comments and assertions (calls to 'panic'). Test case: import-syntax-no-ext - - - - - e669d00e by Vladislav Zavialov at 2025-12-17T14:59:36-05:00 Subordinate namespace-specified wildcards (#25901) Add support for subordinate namespace-specified wildcards `X(type ..)` and `X(data ..)` to import and export lists. Examples: import M (Cls(type ..)) -- imports Cls and all its associated types import M (Cls(data ..)) -- imports Cls and all its methods module M (R(data ..), C(type ..)) where -- exports R and all its data constructors and record fields; -- exports C and all its associated types, but not its methods The scope of this change is limited to the case where the wildcard is the only subordinate import/export item, whereas the more complex forms `X(type .., f)` or `X(type .., data ..)` are unsupported and raise the newly introduced PsErrUnsupportedExplicitNamespace error. This restriction may be lifted later. Summary of the changes: 1. Refactor IEThingAll to store its extension field XIEThingAll as a record IEThingAllExt instead of a tuple. 2. Extend the AST by adding a NamespaceSpecifier field to IEThingAllExt, representing an optional namespace specifier `type` or `data` in front of a subordinate wildcard `X(..)`. 3. Extend the grammar in Parser.y with productions for `type ..` and `data ..` in subordinate import/export items. 4. Introduce `filterByNamespaceGREs` to filter [GlobalRdrElt] by a NamespaceSpecifier; use it in `filterImports` and `exports_from_avail` to account for the namespace specifier in IEThingAll. 5. Improve diagnostics by storing more information in DodgyImportsEmptyParent and DodgyExportsEmptyParent. Test cases: T25901_sub_e T25901_sub_f T25901_sub_g T25901_sub_a T25901_sub_b T25901_sub_c T25901_sub_d T25901_sub_w DodgyImports02 DodgyImports03 DodgyImports04 - - - - - 1f12bb67 by Recursion Ninja at 2025-12-17T14:59:36-05:00 Removing the 'Data' instance for 'InstEnv'. The 'Data' instance is blocking work on Trees that Grow, and the 'Data' instance seem to have been added without a clear purpose. - - - - - 5f6f8b7b by Recursion Ninja at 2025-12-17T14:59:37-05:00 'Decouple Language.Haskell.Syntax.Decls' from 'GHC.Unit.Module.Warnings' - - - - - 0cea194b by Sylvain Henry at 2025-12-17T14:59:59-05:00 Doc: document -pgmi "" (#26634) - - - - - bffb177e by Cheng Shao at 2025-12-17T15:00:02-05:00 rts: use __builtin_mul_overflow for hs_mulIntMayOflo This patch uses `__builtin_mul_overflow` to implement `hs_mulIntMayOflo`. This is a GNU C checked arithmetic builtin function supported by gcc/clang, is type-generic so works for both 32-bit/64-bit, and makes the code both more efficient and easier to read/maintain than the previous hand rolled logic. - - - - - a9de370a by Cheng Shao at 2025-12-17T15:00:03-05:00 compiler/rts: fix ABI mismatch in barf() invocations This patch fixes a long-standing issue of ABI mismatch in `barf()` invocations, both in compiler-emitted code and in hand written Cmm code: - In RTS, we have `barf()` which reports a fatal internal error message and exits the program. - `barf()` is a variadic C function! When used as a callee of a foreign call with `ccall` calling convention instead of `capi`, there is an ABI mismatch between the caller and the callee! - Unfortunately, both the compiler and the Cmm sources contain many places where we call `barf()` via `ccall` convention!! Like, when you write `foreign "C" barf("foo object (%p) entered!", R1)`, it totally doesn't do what you think it'll do at all!! The second argument `R1` is not properly passed in `va_list`, and the behavior is completely undefined!! - Even more unfortunately, this issue has been sitting around long enough because the ABI mismatch is subtle enough on normie platforms like x64 and arm64. - But there are platforms like wasm32 that are stricter about ABI, and the broken `barf()` invocations already causes trouble for wasm backend: we had to use ugly hacks like `barf(errmsg, NULL)` to make `wasm-ld` happy, and even with this band-aid, compiler-generated `barf()` invocations are still broken, resulting in regressions in certain debug-related functionality, e.g. `-dtag-inference-checks` is broken on wasm32 (#22882). This patch properly fixes the issue: - We add non-variadic `barf` wrappers in the RTS that can be used as `ccall` callees - Both the compiler `emitBarf` logic and the hand-written Cmm are changed to call these wrappers - `emitBarf` now also properly annotates the foreign call as `CmmNeverReturns` to indicate it's a noreturn call to enable more efficient code generation `-dtag-inference-checks` now works on wasm. Closes #22882. Co-authored-by: Codex <codex@openai.com> - - - - - 71846e5e by Vilim Lendvaj at 2025-12-17T15:00:07-05:00 Remove outdated comment The Traversable instance for ZipList is no longer in GHC.Internal.Data.Traversable. In fact, it is right below this very comment. - - - - - 105 changed files: - compiler/GHC/Builtin/Utils.hs - compiler/GHC/CmmToAsm/Reg/Graph.hs - compiler/GHC/CmmToAsm/Reg/Graph/Coalesce.hs - compiler/GHC/CmmToAsm/Reg/Graph/Spill.hs - compiler/GHC/CmmToAsm/Reg/Graph/SpillCost.hs - compiler/GHC/CmmToAsm/Reg/Linear.hs - compiler/GHC/CmmToAsm/Reg/Linear/Base.hs - compiler/GHC/CmmToAsm/Reg/Linear/JoinToTargets.hs - compiler/GHC/CmmToAsm/Reg/Liveness.hs - + compiler/GHC/CmmToAsm/Reg/Regs.hs - compiler/GHC/CmmToAsm/Reg/Target.hs - compiler/GHC/CmmToAsm/X86/CodeGen.hs - compiler/GHC/CmmToAsm/X86/Instr.hs - compiler/GHC/CmmToC.hs - compiler/GHC/Core/InstEnv.hs - compiler/GHC/Hs/Decls.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/Hs/Instances.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Warnings.hs - compiler/GHC/Parser.y - compiler/GHC/Parser/Errors/Ppr.hs - compiler/GHC/Parser/Errors/Types.hs - compiler/GHC/Parser/PostProcess.hs - compiler/GHC/Rename/Module.hs - compiler/GHC/Rename/Names.hs - compiler/GHC/Rename/Utils.hs - compiler/GHC/StgToCmm/Bind.hs - compiler/GHC/StgToCmm/Utils.hs - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Deriv/Utils.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Errors/Types.hs - compiler/GHC/Tc/Gen/Export.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Instantiate.hs - compiler/GHC/Types/DefaultEnv.hs - compiler/GHC/Types/Error/Codes.hs - compiler/GHC/Types/Name/Reader.hs - compiler/GHC/Types/Unique/FM.hs - compiler/GHC/Types/Unique/Set.hs - compiler/GHC/Unit/Module/Warnings.hs - compiler/Language/Haskell/Syntax/Decls.hs - compiler/Language/Haskell/Syntax/Extension.hs - compiler/ghc.cabal.in - docs/users_guide/phases.rst - libraries/ghc-internal/src/GHC/Internal/Functor/ZipList.hs - rts/Apply.cmm - rts/Compact.cmm - rts/ContinuationOps.cmm - rts/Exception.cmm - rts/Jumps.h - rts/PrimOps.cmm - rts/RtsMessages.c - rts/StgMiscClosures.cmm - rts/StgStartup.cmm - rts/include/Stg.h - rts/include/rts/Messages.h - rts/prim/mulIntMayOflo.c - testsuite/tests/diagnostic-codes/codes.stdout - testsuite/tests/haddock/should_compile_flag_haddock/T17544_kw.stderr - testsuite/tests/patsyn/should_fail/all.T - + testsuite/tests/patsyn/should_fail/import-syntax-no-ext.hs - + testsuite/tests/patsyn/should_fail/import-syntax-no-ext.stderr - + testsuite/tests/rename/should_compile/T25901_sub_e.hs - + testsuite/tests/rename/should_compile/T25901_sub_f.hs - + testsuite/tests/rename/should_compile/T25901_sub_f.stderr - + testsuite/tests/rename/should_compile/T25901_sub_g.hs - + testsuite/tests/rename/should_compile/T25901_sub_g.stderr - + testsuite/tests/rename/should_compile/T25901_sub_g_helper.hs - testsuite/tests/rename/should_compile/all.T - testsuite/tests/rename/should_fail/T23570b.stderr - + testsuite/tests/rename/should_fail/T25901_sub_a.hs - + testsuite/tests/rename/should_fail/T25901_sub_a.stderr - + testsuite/tests/rename/should_fail/T25901_sub_b.hs - + testsuite/tests/rename/should_fail/T25901_sub_b.stderr - + testsuite/tests/rename/should_fail/T25901_sub_c.hs - + testsuite/tests/rename/should_fail/T25901_sub_c.stderr - + testsuite/tests/rename/should_fail/T25901_sub_c_helper.hs - + testsuite/tests/rename/should_fail/T25901_sub_d.hs - + testsuite/tests/rename/should_fail/T25901_sub_d.stderr - + testsuite/tests/rename/should_fail/T25901_sub_d_helper.hs - + testsuite/tests/rename/should_fail/T25901_sub_w.hs - + testsuite/tests/rename/should_fail/T25901_sub_w.stderr - testsuite/tests/rename/should_fail/all.T - + testsuite/tests/simd/should_run/T26411.hs - + testsuite/tests/simd/should_run/T26411.stdout - + testsuite/tests/simd/should_run/T26411b.hs - + testsuite/tests/simd/should_run/T26411b.stdout - testsuite/tests/simd/should_run/all.T - testsuite/tests/simplStg/should_compile/all.T - testsuite/tests/warnings/should_compile/DodgyExports03.stderr - testsuite/tests/warnings/should_compile/DodgyImports.stderr - + testsuite/tests/warnings/should_compile/DodgyImports02.hs - + testsuite/tests/warnings/should_compile/DodgyImports02.stderr - + testsuite/tests/warnings/should_compile/DodgyImports03.hs - + testsuite/tests/warnings/should_compile/DodgyImports03.stderr - + testsuite/tests/warnings/should_compile/DodgyImports03_helper.hs - + testsuite/tests/warnings/should_compile/DodgyImports04.hs - + testsuite/tests/warnings/should_compile/DodgyImports04.stderr - testsuite/tests/warnings/should_compile/DodgyImports_hiding.stderr - testsuite/tests/warnings/should_compile/all.T - utils/check-exact/ExactPrint.hs - utils/genapply/Main.hs - utils/haddock/haddock-api/src/Haddock/Interface/Create.hs The diff was not included because it is too large. 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