From fe789978453bfd4e5ff456a6be57fc8041664d75 Mon Sep 17 00:00:00 2001
From: Sylvain Henry <sylvain@haskus.fr>
Date: Tue, 2 Feb 2021 14:41:41 +0100
Subject: IntVar: fix allocation size
As found by @phadej in https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4740/diffs#note_327510
Also fix FastMutInt which allocating the size in bits instead of bytes.
---
libraries/base/GHC/Event/IntVar.hs | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
(limited to 'libraries/base/GHC')
diff --git a/libraries/base/GHC/Event/IntVar.hs b/libraries/base/GHC/Event/IntVar.hs
index f52deebd00..f973a34bfb 100644
--- a/libraries/base/GHC/Event/IntVar.hs
+++ b/libraries/base/GHC/Event/IntVar.hs
@@ -1,4 +1,5 @@
{-# LANGUAGE Trustworthy #-}
+{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP, MagicHash, NoImplicitPrelude, UnboxedTuples #-}
module GHC.Event.IntVar
@@ -9,13 +10,15 @@ module GHC.Event.IntVar
) where
import GHC.Base
+import GHC.Bits
data IntVar = IntVar (MutableByteArray# RealWorld)
newIntVar :: Int -> IO IntVar
newIntVar n = do
+ let !(I# size) = finiteBitSize (0 :: Int) `unsafeShiftR` 3
iv <- IO $ \s ->
- case newByteArray# 1# s of
+ case newByteArray# size s of
(# s', mba #) -> (# s', IntVar mba #)
writeIntVar iv n
return iv
--
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