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| author | Johan Tibell <johan.tibell@gmail.com> | 2014-03-23 12:06:56 +0100 |
|---|---|---|
| committer | Johan Tibell <johan.tibell@gmail.com> | 2014-03-29 11:24:07 +0100 |
| commit | 90329b6cc183b3cd05956ae6bdeb6ac6951549c2 (patch) | |
| tree | ba7d31656fe75fad2555c8a66b7ebd13dd9ebeb1 /includes/Cmm.h | |
| 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 'includes/Cmm.h')
| -rw-r--r-- | includes/Cmm.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/includes/Cmm.h b/includes/Cmm.h index 13e485f627..24bdda30c5 100644 --- a/includes/Cmm.h +++ b/includes/Cmm.h @@ -806,6 +806,10 @@ __gen = TO_W_(bdescr_gen_no(__bd)); \ if (__gen > 0) { recordMutableCap(__p, __gen); } +/* ----------------------------------------------------------------------------- + Arrays + -------------------------------------------------------------------------- */ + /* Complete function body for the clone family of (mutable) array ops. Defined as a macro to avoid function call overhead or code duplication. */ @@ -890,4 +894,33 @@ __cards = __end_card - __start_card + 1; \ prim %memset((dst_cards_p) + __start_card, 1, __cards, 1); +/* Complete function body for the clone family of small (mutable) + array ops. Defined as a macro to avoid function call overhead or + code duplication. */ +#define cloneSmallArray(info, src, offset, n) \ + W_ words, size; \ + gcptr dst, dst_p, src_p; \ + \ + again: MAYBE_GC(again); \ + \ + words = BYTES_TO_WDS(SIZEOF_StgSmallMutArrPtrs) + n; \ + ("ptr" dst) = ccall allocate(MyCapability() "ptr", words); \ + TICK_ALLOC_PRIM(SIZEOF_StgSmallMutArrPtrs, WDS(n), 0); \ + \ + SET_HDR(dst, info, CCCS); \ + StgSmallMutArrPtrs_ptrs(dst) = n; \ + \ + dst_p = dst + SIZEOF_StgSmallMutArrPtrs; \ + src_p = src + SIZEOF_StgSmallMutArrPtrs + WDS(offset); \ + while: \ + if (n != 0) { \ + n = n - 1; \ + W_[dst_p] = W_[src_p]; \ + dst_p = dst_p + WDS(1); \ + src_p = src_p + WDS(1); \ + goto while; \ + } \ + \ + return (dst); + #endif /* CMM_H */ |