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author | Johan Tibell <johan.tibell@gmail.com> | 2014-03-23 12:06:56 +0100 |
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committer | Johan Tibell <johan.tibell@gmail.com> | 2014-03-29 11:24:07 +0100 |
commit | 90329b6cc183b3cd05956ae6bdeb6ac6951549c2 (patch) | |
tree | ba7d31656fe75fad2555c8a66b7ebd13dd9ebeb1 /utils/deriveConstants | |
parent | 4c8edfd2c722504baaa6896d194fd3a8c3f9b652 (diff) | |
download | haskell-90329b6cc183b3cd05956ae6bdeb6ac6951549c2.tar.gz |
Add SmallArray# and SmallMutableArray# types
These array types are smaller than Array# and MutableArray# and are
faster when the array size is small, as they don't have the overhead
of a card table. Having no card table reduces the closure size with 2
words in the typical small array case and leads to less work when
updating or GC:ing the array.
Reduces both the runtime and memory allocation by 8.8% on my insert
benchmark for the HashMap type in the unordered-containers package,
which makes use of lots of small arrays. With tuned GC settings
(i.e. `+RTS -A6M`) the runtime reduction is 15%.
Fixes #8923.
Diffstat (limited to 'utils/deriveConstants')
-rw-r--r-- | utils/deriveConstants/DeriveConstants.hs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/utils/deriveConstants/DeriveConstants.hs b/utils/deriveConstants/DeriveConstants.hs index 293fe65492..8c943f0584 100644 --- a/utils/deriveConstants/DeriveConstants.hs +++ b/utils/deriveConstants/DeriveConstants.hs @@ -391,6 +391,9 @@ wanteds = concat ,closureField Both "StgMutArrPtrs" "ptrs" ,closureField Both "StgMutArrPtrs" "size" + ,closureSize Both "StgSmallMutArrPtrs" + ,closureField Both "StgSmallMutArrPtrs" "ptrs" + ,closureSize Both "StgArrWords" ,closureField Both "StgArrWords" "bytes" ,closurePayload C "StgArrWords" "payload" |