David Eichmann pushed to branch wip/davide/windows-dlls at Glasgow Haskell Compiler / GHC Commits: 8ad3341a by David Eichmann at 2026-05-14T17:19:15+01:00 WIP static CAFs - - - - - 2 changed files: - compiler/GHC/Cmm/Info/Build.hs - compiler/GHC/StgToCmm/Bind.hs Changes: ===================================== compiler/GHC/Cmm/Info/Build.hs ===================================== @@ -1295,15 +1295,17 @@ updInfoSRTs profile srt_env funSRTEnv caffy (CmmProc top_info top_l live g) | l == g_entry g, Just (inf, _) <- maybeStaticClosure = inf | otherwise = info_tbl { cit_srt = mapLookup l srt_env } - -- Generate static closures [FUN]. Note that this also generates - -- static closures for thunks (CAFs), because it's easier to treat - -- them uniformly in the code generator. + -- Generate static closures [FUN]. CAF thunks are excluded: they are + -- treated as dynamic closures and have their closure data emitted in + -- GHC.StgToCmm.Bind.cgTopRhsClosure; the cit_clo guard below is + -- sufficient to rule them out since dynamic thunks have cit_clo=Nothing. maybeStaticClosure :: Maybe (CmmInfoTable, CmmDeclSRTs) maybeStaticClosure | Just info_tbl@CmmInfoTable{..} <- mapLookup (g_entry g) (info_tbls top_info) , Just (id, ccs) <- cit_clo - , isStaticRep cit_rep = + , isStaticRep cit_rep + , not (isThunkRep cit_rep) = let (newInfo, srtEntries) = case mapLookup (g_entry g) funSRTEnv of Nothing -> ===================================== compiler/GHC/StgToCmm/Bind.hs ===================================== @@ -129,17 +129,24 @@ cgTopRhsClosure platform rec id ccs upd_flag args body = emitDecl $ CmmData (Section Data closure_label) $ CmmStatics closure_label info ccs [] [lit] - gen_code lf_info _closure_label + gen_code lf_info closure_label = do { profile <- getProfile ; let name = idName id ; mod_name <- getModuleName ; let descr = closureDescription mod_name name - closure_info = mkClosureInfo profile True id lf_info 0 0 descr - - -- We don't generate the static closure here, because we might - -- want to add references to static closures to it later. The - -- static closure is generated by GHC.Cmm.Info.Build.updInfoSRTs, - -- See Note [SRTs], specifically the [FUN] optimisation. + -- CAFs (top-level updatable thunks with no arguments) are treated + -- as dynamic closures: they use heap-style thunk update semantics + -- and do not call newCAF/link_caf. + is_caf = isLFThunk lf_info && lfUpdatable lf_info + closure_info = mkClosureInfo profile (not is_caf) id lf_info 0 0 descr + + -- We don't generate the static closure here for non-CAF top-level + -- closures, because we might want to add references to static closures + -- to it later. The static closure is generated by + -- GHC.Cmm.Info.Build.updInfoSRTs, See Note [SRTs], specifically the + -- [FUN] optimisation. + -- For CAFs we generate the closure data immediately: they are dynamic + -- (heap-style thunks) so maybeStaticClosure will not pick them up. ; let fv_details :: [(NonVoid Id, ByteOff)] header = if isLFThunk lf_info then ThunkHeader else StdHeader @@ -148,6 +155,10 @@ cgTopRhsClosure platform rec id ccs upd_flag args body = ; forkClosureBody (closureCodeBody True id closure_info ccs args body fv_details) + ; when is_caf $ + emitDecl $ CmmData (Section Data closure_label) $ + CmmStatics closure_label (mkCmmInfo closure_info id ccs) ccs [] [] + ; return () } unLit (CmmLit l) = l View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/8ad3341a0c3678b0f6a4d0daffa0b538... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/8ad3341a0c3678b0f6a4d0daffa0b538... You're receiving this email because of your account on gitlab.haskell.org.