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| author | Andreas Klebinger <klebinger.andreas@gmx.at> | 2023-02-03 14:10:30 +0100 |
|---|---|---|
| committer | Andreas Klebinger <klebinger.andreas@gmx.at> | 2023-02-03 14:10:30 +0100 |
| commit | d6cb3ffefa2cdc0c183fdc9449f6efd5fcce9757 (patch) | |
| tree | 2b1084449c0f1770de6d0cf663cdaa782c0b6857 | |
| parent | 8feb93013cf6f093e025c9e9a3213ae1fa0f73a0 (diff) | |
| download | haskell-wip/andreask/ww-noinline-dicts.tar.gz | |
W/W dicts if they are arguments to an NOINLINE function.wip/andreask/ww-noinline-dicts
We usually avoid doing so to ensure functions specialize. But since we
don't specialize these functions there is reason not to do full W/W on
them.
Fixes #22758
| -rw-r--r-- | compiler/GHC/Core/Opt/DmdAnal.hs | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/compiler/GHC/Core/Opt/DmdAnal.hs b/compiler/GHC/Core/Opt/DmdAnal.hs index 0bcabf55d3..282a85d90d 100644 --- a/compiler/GHC/Core/Opt/DmdAnal.hs +++ b/compiler/GHC/Core/Opt/DmdAnal.hs @@ -1772,6 +1772,10 @@ We never unbox class dictionaries in worker/wrapper. to inline; the inlining heuristics seem to prefer to inline a function applied to a dictionary over a function applied to a bunch of functions. +4. We still W/W NOINLINE functions. The specialiser currently won't specialise + these anyway so there is no reason not to. + See Note [Auto-specialisation and RULES] + TL;DR we /never/ unbox class dictionaries. Unboxing the dictionary, and passing a raft of higher-order functions isn't a huge win anyway -- you really want to specialise the function. @@ -1964,7 +1968,8 @@ finaliseArgBoxities env fn threshold_arity rhs_dmds div rhs get_dmd :: Id -> Type -> Demand get_dmd bndr bndr_ty - | isClassPred bndr_ty = trimBoxity dmd + | isClassPred bndr_ty + , not (isNeverActive (idInlineActivation fn)) = trimBoxity dmd -- See Note [Do not unbox class dictionaries] -- NB: 'ty' has not been normalised, so this will (rightly) -- catch newtype dictionaries too. |