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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/specialise | |
| 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/specialise')
| -rw-r--r-- | compiler/specialise/Rules.hs | 4 | ||||
| -rw-r--r-- | compiler/specialise/Specialise.hs | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/compiler/specialise/Rules.hs b/compiler/specialise/Rules.hs index 3380d02f99..4a4abf768b 100644 --- a/compiler/specialise/Rules.hs +++ b/compiler/specialise/Rules.hs @@ -350,7 +350,7 @@ mkRuleBase rules = extendRuleBaseList emptyRuleBase rules extendRuleBaseList :: RuleBase -> [CoreRule] -> RuleBase extendRuleBaseList rule_base new_guys - = foldl extendRuleBase rule_base new_guys + = foldl' extendRuleBase rule_base new_guys unionRuleBase :: RuleBase -> RuleBase -> RuleBase unionRuleBase rb1 rb2 = plusNameEnv_C (++) rb1 rb2 @@ -907,7 +907,7 @@ match_alts renv subst ((c1,vs1,r1):alts1) ((c2,vs2,r2):alts2) = do { subst1 <- match renv' subst r1 r2 ; match_alts renv subst1 alts1 alts2 } where - renv' = foldl mb renv (vs1 `zip` vs2) + renv' = foldl' mb renv (vs1 `zip` vs2) mb renv (v1,v2) = rnMatchBndr2 renv subst v1 v2 match_alts _ _ _ _ diff --git a/compiler/specialise/Specialise.hs b/compiler/specialise/Specialise.hs index 13a7cb7474..6f775dfdcb 100644 --- a/compiler/specialise/Specialise.hs +++ b/compiler/specialise/Specialise.hs @@ -2096,7 +2096,7 @@ mkDB bind = (bind, bind_fvs bind) -- | Identify the free variables of a 'CoreBind' bind_fvs :: CoreBind -> VarSet bind_fvs (NonRec bndr rhs) = pair_fvs (bndr,rhs) -bind_fvs (Rec prs) = foldl delVarSet rhs_fvs bndrs +bind_fvs (Rec prs) = foldl' delVarSet rhs_fvs bndrs where bndrs = map fst prs rhs_fvs = unionVarSets (map pair_fvs prs) |