diff options
| 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/stranal | |
| 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/stranal')
| -rw-r--r-- | compiler/stranal/DmdAnal.hs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/stranal/DmdAnal.hs b/compiler/stranal/DmdAnal.hs index 77da307263..b606804079 100644 --- a/compiler/stranal/DmdAnal.hs +++ b/compiler/stranal/DmdAnal.hs @@ -644,7 +644,7 @@ dmdAnalRhsLetDown top_lvl rec_flag env let_dmd id rhs Nothing | (bndrs, body) <- collectBinders rhs -> (bndrs, body, mkBodyDmd env body) - env_body = foldl extendSigsWithLam env bndrs + env_body = foldl' extendSigsWithLam env bndrs (body_ty, body') = dmdAnal env_body body_dmd body body_ty' = removeDmdTyArgs body_ty -- zap possible deep CPR info (DmdType rhs_fv rhs_dmds rhs_res, bndrs') @@ -1193,7 +1193,7 @@ extendSigsWithLam env id extendEnvForProdAlt :: AnalEnv -> CoreExpr -> Id -> DataCon -> [Var] -> AnalEnv -- See Note [CPR in a product case alternative] extendEnvForProdAlt env scrut case_bndr dc bndrs - = foldl do_con_arg env1 ids_w_strs + = foldl' do_con_arg env1 ids_w_strs where env1 = extendAnalEnv NotTopLevel env case_bndr case_bndr_sig |