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Wolfgang Jeltsch pushed to branch wip/jeltsch/more-efficient-home-unit-imports-finding.jeltsch-experiment at Glasgow Haskell Compiler / GHC

WARNING: The push did not contain any new commits, but force pushed to delete the commits and changes below.

Deleted commits:

e49a16cd

by Wolfgang Jeltsch at 2026-04-11T16:46:04+03:00

Drop the construction and use of `other_fopts_map`

The map was only used for a single lookup, and directly performing the
lookup in the original list is faster than constructing the map and then
performing the lookup in the map.

1 changed file:

compiler/GHC/Unit/Finder.hs

Changes:

compiler/GHC/Unit/Finder.hs

@@ -206,7 +206,7 @@ findImportedModuleNoHsc fc fopts ue home_module_map mhome_unit mod_name mb_pkg =
    case mb_pkg of
      NoPkgQual  -> unqual_import
      ThisPkg uid | (homeUnitId <$> mhome_unit) == Just uid -> home_import
 -                | Just os <- M.lookup uid other_fopts_map -> home_pkg_import (uid, os)
 +                | Just os <- lookup uid other_fopts -> home_pkg_import (uid, os)
                  | otherwise -> pprPanic "findImportModule" (ppr mod_name $$ ppr mb_pkg $$ ppr (homeUnitId <$> mhome_unit) $$ ppr uid $$ ppr (map fst all_opts))
      OtherPkg _ -> pkg_import
    where
@@ -214,10 +214,8 @@ findImportedModuleNoHsc fc fopts ue home_module_map mhome_unit mod_name mb_pkg =
      module_home_units = M.findWithDefault Set.empty mod_name module_name_map
      current_unit_id = homeUnitId <$> mhome_unit
      all_opts = case current_unit_id of
 -                Nothing -> other_fopts_list
 -                Just home_unit_id -> (home_unit_id, fopts) : other_fopts_list
+-
 -    other_fopts_map = M.fromList other_fopts_list
 +                Nothing -> other_fopts
 +                Just home_unit_id -> (home_unit_id, fopts) : other_fopts
      home_import = case mhome_unit of
                     Just home_unit -> findHomeModule fc fopts home_unit mod_name
@@ -237,7 +235,7 @@ findImportedModuleNoHsc fc fopts ue home_module_map mhome_unit mod_name mb_pkg =
      -- Do not be smart and change this to `foldr orIfNotFound home_import hs` as
      -- that is not the same!! home_import is first because we need to look within ourselves
      -- first before looking at the packages in order.
 -    any_home_import = foldr1 orIfNotFound (home_import :| map home_pkg_import other_fopts_list)
 +    any_home_import = foldr1 orIfNotFound (home_import :| map home_pkg_import other_fopts)
      pkg_import    = findExposedPackageModule fc fopts units  mod_name mb_pkg
@@ -259,7 +257,7 @@ findImportedModuleNoHsc fc fopts ue home_module_map mhome_unit mod_name mb_pkg =
            excluded = maybe Set.empty Set.singleton {- maybe dep_providers (\u -> Set.insert u dep_providers) -} current_unit_id
        in Set.toList (Set.difference candidates excluded)
      other_home_uids = known_other_uids ++ unknown_units
 -    other_fopts_list =
 +    other_fopts =
        [ (uid, initFinderOpts (homeUnitEnv_dflags (ue_findHomeUnitEnv uid ue)))
        | uid <- other_home_uids
+       ]