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| author | klebinger.andreas@gmx.at <klebinger.andreas@gmx.at> | 2018-08-21 12:10:38 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2018-08-21 18:52:42 -0400 |
| commit | 09c1d5afba655a2427a448a9933bebe7d13b696b (patch) | |
| tree | d23083a9e99afe785f632e89f0186af8b191aee2 /compiler/typecheck/TcPatSyn.hs | |
| parent | 02518f9d99c2d038384263f9e039efcb09bc96ff (diff) | |
| download | haskell-09c1d5afba655a2427a448a9933bebe7d13b696b.tar.gz | |
Replace most occurences of foldl with foldl'.
This patch adds foldl' to GhcPrelude and changes must occurences
of foldl to foldl'. This leads to better performance especially
for quick builds where GHC does not perform strictness analysis.
It does change strictness behaviour when we use foldl' to turn
a argument list into function applications. But this is only a
drawback if code looks ONLY at the last argument but not at the first.
And as the benchmarks show leads to fewer allocations in practice
at O2.
Compiler performance for Nofib:
O2 Allocations:
-1 s.d. ----- -0.0%
+1 s.d. ----- -0.0%
Average ----- -0.0%
O2 Compile Time:
-1 s.d. ----- -2.8%
+1 s.d. ----- +1.3%
Average ----- -0.8%
O0 Allocations:
-1 s.d. ----- -0.2%
+1 s.d. ----- -0.1%
Average ----- -0.2%
Test Plan: ci
Reviewers: goldfire, bgamari, simonmar, tdammers, monoidal
Reviewed By: bgamari, monoidal
Subscribers: tdammers, rwbarton, thomie, carter
Differential Revision: https://phabricator.haskell.org/D4929
Diffstat (limited to 'compiler/typecheck/TcPatSyn.hs')
| -rw-r--r-- | compiler/typecheck/TcPatSyn.hs | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/compiler/typecheck/TcPatSyn.hs b/compiler/typecheck/TcPatSyn.hs index fabe16a1e0..3165c8739a 100644 --- a/compiler/typecheck/TcPatSyn.hs +++ b/compiler/typecheck/TcPatSyn.hs @@ -718,7 +718,7 @@ tcPatSynMatcher (L loc name) lpat -- See Note [Exported LocalIds] in Id inst_wrap = mkWpEvApps prov_dicts <.> mkWpTyApps ex_tys - cont' = foldl nlHsApp (mkLHsWrap inst_wrap (nlHsVar cont)) cont_args + cont' = foldl' nlHsApp (mkLHsWrap inst_wrap (nlHsVar cont)) cont_args fail' = nlHsApps fail [nlHsVar voidPrimId] @@ -926,8 +926,8 @@ tcPatToExpr name args pat = go pat -> Either MsgDoc (HsExpr GhcRn) mkPrefixConExpr lcon@(L loc _) pats = do { exprs <- mapM go pats - ; return (foldl (\x y -> HsApp noExt (L loc x) y) - (HsVar noExt lcon) exprs) } + ; return (foldl' (\x y -> HsApp noExt (L loc x) y) + (HsVar noExt lcon) exprs) } mkRecordConExpr :: Located Name -> HsRecFields GhcRn (LPat GhcRn) -> Either MsgDoc (HsExpr GhcRn) |