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| author | Matthew Pickering <matthewtpickering@gmail.com> | 2022-08-10 09:16:43 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-08-19 00:09:11 -0400 |
| commit | 4303acba89b26cc3ae05527d701cba7d84edafcb (patch) | |
| tree | 3c1acefbd8183dce75582a64819423c5dbf88f49 | |
| parent | 7dda04b00407c083949363b653538510a1355e12 (diff) | |
| download | haskell-4303acba89b26cc3ae05527d701cba7d84edafcb.tar.gz | |
Force unfoldings when they are cleaned-up in Tidy and CorePrep
If these thunks are not forced then the entire unfolding for the binding
is live throughout the whole of CodeGen despite the fact it should have
been discarded.
Fixes #22071
| -rw-r--r-- | compiler/GHC/CoreToStg/Prep.hs | 4 | ||||
| -rw-r--r-- | compiler/GHC/Iface/Tidy.hs | 6 |
2 files changed, 7 insertions, 3 deletions
diff --git a/compiler/GHC/CoreToStg/Prep.hs b/compiler/GHC/CoreToStg/Prep.hs index 6f02d8e3a2..2405a2feda 100644 --- a/compiler/GHC/CoreToStg/Prep.hs +++ b/compiler/GHC/CoreToStg/Prep.hs @@ -2153,7 +2153,9 @@ cpCloneBndr env bndr -- Drop (now-useless) rules/unfoldings -- See Note [Drop unfoldings and rules] -- and Note [Preserve evaluatedness] in GHC.Core.Tidy - ; let unfolding' = trimUnfolding (realIdUnfolding bndr) + -- And force it.. otherwise the old unfolding is just retained. + -- See #22071 + ; let !unfolding' = trimUnfolding (realIdUnfolding bndr) -- Simplifier will set the Id's unfolding bndr'' = bndr' `setIdUnfolding` unfolding' diff --git a/compiler/GHC/Iface/Tidy.hs b/compiler/GHC/Iface/Tidy.hs index 5f22f0275a..92e7e3c0df 100644 --- a/compiler/GHC/Iface/Tidy.hs +++ b/compiler/GHC/Iface/Tidy.hs @@ -1292,12 +1292,14 @@ tidyTopIdInfo uf_opts rhs_tidy_env name rhs_ty orig_rhs tidy_rhs idinfo show_unf --------- Unfolding ------------ unf_info = realUnfoldingInfo idinfo - unfold_info + -- Force this, otherwise the old unfolding is retained over code generation + -- See #22071 + !unfold_info | isCompulsoryUnfolding unf_info || show_unfold = tidyUnfolding rhs_tidy_env unf_info unf_from_rhs | otherwise = minimal_unfold_info - minimal_unfold_info = trimUnfolding unf_info + !minimal_unfold_info = trimUnfolding unf_info unf_from_rhs = mkFinalUnfolding uf_opts InlineRhs final_sig tidy_rhs -- NB: do *not* expose the worker if show_unfold is off, -- because that means this thing is a loop breaker or |