Andreas Klebinger pushed to branch wip/apk/unfold-dicts at Glasgow Haskell Compiler / GHC Commits: 6a40d4b6 by Andreas Klebinger at 2026-09-11T20:24:24+02:00 Try discounting args applied to a result of a class op - - - - - 1 changed file: - compiler/GHC/Core/Unfold.hs Changes: ===================================== compiler/GHC/Core/Unfold.hs ===================================== @@ -42,7 +42,7 @@ import GHC.Core.Utils import GHC.Core.DataCon import GHC.Core.Type import GHC.Core.Class( Class ) -import GHC.Core.Predicate( isUnaryClass ) +import GHC.Core.Predicate( isUnaryClass, isDictId ) import GHC.Types.Id import GHC.Types.Literal @@ -782,7 +782,7 @@ classOpSize :: UnfoldingOpts -> Class -> [Id] -> [CoreExpr] -> ExprSize classOpSize _opts _cls _top_args [] = sizeZero -- A non-applied classop classOpSize opts cls top_args (dict_arg:other_val_args) - = SizeIs size (dict_arg_discount dict_arg) 0 + = SizeIs size dict_arg_discount 0 where -- See (UCM4) in Note [Unary class magic] in GHC.Core.TyCon op_app_size = if isUnaryClass cls then 0 else 20 @@ -797,8 +797,8 @@ classOpSize opts cls top_args (dict_arg:other_val_args) -- give it a discount, to encourage the inlining of this function dict_arg_discount = case getIdFromTrivialExpr_maybe dict_arg of Nothing -> emptyBag - Just var - | var `elem` top_args = unitBag (dict, dict_discount) + Just dict + | dict `elem` top_args -> unitBag (dict, dict_discount) | otherwise -> emptyBag -- If we have (class-op d arg1 .. argn) then it's super-good to inline @@ -808,7 +808,15 @@ classOpSize opts cls top_args (dict_arg:other_val_args) -- See the discussion on #26831, esp "Delicate inlining". dict_discount | null other_val_args = unfoldingDictDiscount opts - | otherwise = unfoldingDictDiscount opts + unfoldingFunAppDiscount opts + | otherwise = unfoldingDictDiscount opts + unfoldingFunAppDiscount opts + + -- Just trying things. + 5 * numTopDictArgs + numTopDictArgs = (count (isTopArgDict) other_val_args) + isTopArgDict expr + | Just v <- getIdFromTrivialExpr_maybe expr + , v `elem` top_args + = isDictId v + | otherwise = False -- | The size of a function call callSize View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/6a40d4b68d3bdfd7c5d3f9f1627ed324... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/6a40d4b68d3bdfd7c5d3f9f1627ed324... 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