diff options
| author | Joachim Breitner <mail@joachim-breitner.de> | 2021-10-15 10:38:23 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-10-19 03:30:52 -0400 |
| commit | 7271bf78a9ffd865e590f1ce3f3ae975f5dc1a49 (patch) | |
| tree | 4c1eb9dbf7c3698f4462ae9fa7d7ac13ef89eb9e /compiler/GHC/Tc/Module.hs | |
| parent | 753b921da52c0b7da21856c5fe0bf4604505c7b3 (diff) | |
| download | haskell-7271bf78a9ffd865e590f1ce3f3ae975f5dc1a49.tar.gz | |
InteractiveContext: Smarter caching when rebuilding the ic_rn_gbl_env
The GlobalRdrEnv of a GHCI session changes in odd ways: New bindings are
not just added "to the end", but also "in the middle", namely when
changing the set of imports: These are treated as if they happened
before all bindings from the prompt, even those that happened earlier.
Previously, this meant that the `ic_rn_gbl_env` is recalculated from the
`ic_tythings`. But this wasteful if `ic_tythings` has many entries that
define the same unqualified name. By separately keeping track of a
`GlobalRdrEnv` of all the locally defined things we can speed this
operation up significantly.
This change improves `T14052Type` by 60% (It used to be 70%, but it
looks that !6723 already reaped some of the rewards).
But more importantly, it hopefully unblocks #20455, becaues with this
smarter caching, the change needed to fix that issue will no longer make
`T14052` explode. I hope.
It does regress `T14052` by 30%; caching isn’t free. Oh well.
Metric Decrease:
T14052Type
Metric Increase:
T14052
Diffstat (limited to 'compiler/GHC/Tc/Module.hs')
| -rw-r--r-- | compiler/GHC/Tc/Module.hs | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/compiler/GHC/Tc/Module.hs b/compiler/GHC/Tc/Module.hs index 8739c33ec5..53ee34ed9e 100644 --- a/compiler/GHC/Tc/Module.hs +++ b/compiler/GHC/Tc/Module.hs @@ -2040,8 +2040,8 @@ runTcInteractive hsc_env thing_inside do { traceTc "setInteractiveContext" $ vcat [ text "ic_tythings:" <+> vcat (map ppr (ic_tythings icxt)) , text "ic_insts:" <+> vcat (map (pprBndr LetBind . instanceDFunId) ic_insts) - , text "ic_rn_gbl_env (LocalDef)" <+> - vcat (map ppr [ local_gres | gres <- nonDetOccEnvElts (ic_rn_gbl_env icxt) + , text "icReaderEnv (LocalDef)" <+> + vcat (map ppr [ local_gres | gres <- nonDetOccEnvElts (icReaderEnv icxt) , let local_gres = filter isLocalGRE gres , not (null local_gres) ]) ] @@ -2063,7 +2063,7 @@ runTcInteractive hsc_env thing_inside ; (gbl_env, lcl_env) <- getEnvs ; let gbl_env' = gbl_env { - tcg_rdr_env = ic_rn_gbl_env icxt + tcg_rdr_env = icReaderEnv icxt , tcg_type_env = type_env , tcg_inst_env = extendInstEnvList (extendInstEnvList (tcg_inst_env gbl_env) ic_insts) @@ -2910,7 +2910,7 @@ loadUnqualIfaces hsc_env ictxt home_unit = hsc_home_unit hsc_env unqual_mods = [ nameModule name - | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt) + | gre <- globalRdrEnvElts (icReaderEnv ictxt) , let name = greMangledName gre , nameIsFromExternalPackage home_unit name , isTcOcc (nameOccName name) -- Types and classes only |