From 82dcce6757d7f795ea477b5532d09bdb6d717235 Mon Sep 17 00:00:00 2001
From: Cheng Shao <terrorjack@type.dance>
Date: Mon, 3 Feb 2025 16:15:55 +0000
Subject: [PATCH] compiler: use fromAscList when applicable
This patch uses fromAscList (with O(n) complexity) instead of fromList
(with O(nlogn) complexity) in certain Binary instances. It's safe to
do so since the corresponding serialization logic is based on toList
(same as toAscList).
(cherry picked from commit 1c8e608a84b9d54abb352b59a592d4669872517e)
---
compiler/GHC/Utils/Binary.hs | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/compiler/GHC/Utils/Binary.hs b/compiler/GHC/Utils/Binary.hs
index 4927ad3a454..3f3463370b4 100644
--- a/compiler/GHC/Utils/Binary.hs
+++ b/compiler/GHC/Utils/Binary.hs
@@ -946,8 +946,8 @@ instance Binary a => Binary [a] where
-- | This instance doesn't rely on the determinism of the keys' 'Ord' instance,
-- so it works e.g. for 'Name's too.
instance (Binary a, Ord a) => Binary (Set a) where
- put_ bh s = put_ bh (Set.toList s)
- get bh = Set.fromList <$> get bh
+ put_ bh s = put_ bh (Set.toAscList s)
+ get bh = Set.fromAscList <$> get bh
instance Binary a => Binary (NonEmpty a) where
put_ bh = put_ bh . NonEmpty.toList
@@ -2092,5 +2092,5 @@ source location as part of a larger structure.
--------------------------------------------------------------------------------
instance (Binary v) => Binary (IntMap v) where
- put_ bh m = put_ bh (IntMap.toList m)
- get bh = IntMap.fromList <$> get bh
+ put_ bh m = put_ bh (IntMap.toAscList m)
+ get bh = IntMap.fromAscList <$> get bh
--
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