Defining a custom newByteArray primop that uses calloc?
In my tests, using calloc from: https://hackage.haskell.org/package/missing-foreign-0.1.1/docs/Foreign-Marsh... was about twice as fast as allocating and zeroing the same amount of memory with `newByteArray` + any of `copy/set/fillMutableByteArray` (all three were nearly identical). Is there a way I can reasonably define my own `newByteArray` that uses calloc? FWIW here are a couple of the benchmarks I'm working with in criterion: arrTestSet :: Int -> IO () arrTestSet len = do let eBytes = (P.sizeOf (undefined::Int))*len a <- P.newAlignedPinnedByteArray eBytes (P.alignment (undefined :: Int)) void $ P.setByteArray a 0 len (1::Int) arrTestCallocAndWrite :: Int -> IO () arrTestCallocAndWrite len = do ptr <- callocBytes (len*(P.sizeOf(undefined::Int))) :: IO (Ptr Int) pokeElemOff ptr 0 1 free ptr Thanks, Brandon
Brandon Simmons wrote:
In my tests, using calloc from:
https://hackage.haskell.org/package/missing-foreign-0.1.1/docs/Foreign-Marsh...
was about twice as fast as allocating and zeroing the same amount of memory with `newByteArray` + any of `copy/set/fillMutableByteArray` (all three were nearly identical). Is there a way I can reasonably define my own `newByteArray` that uses calloc?
FWIW here are a couple of the benchmarks I'm working with in criterion:
arrTestSet :: Int -> IO () arrTestSet len = do let eBytes = (P.sizeOf (undefined::Int))*len a <- P.newAlignedPinnedByteArray
Why pinned memory? Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/
you cant provide > 1 word alignment guarantees if the bytearray isnt
pinned, ... at least with the current RTS setup. (though that would be
pretty handy if possible)
On Wed, Nov 26, 2014 at 8:55 PM, Erik de Castro Lopo
Brandon Simmons wrote:
In my tests, using calloc from:
https://hackage.haskell.org/package/missing-foreign-0.1.1/docs/Foreign-Marsh...
was about twice as fast as allocating and zeroing the same amount of memory with `newByteArray` + any of `copy/set/fillMutableByteArray` (all three were nearly identical). Is there a way I can reasonably define my own `newByteArray` that uses calloc?
FWIW here are a couple of the benchmarks I'm working with in criterion:
arrTestSet :: Int -> IO () arrTestSet len = do let eBytes = (P.sizeOf (undefined::Int))*len a <- P.newAlignedPinnedByteArray
Why pinned memory?
Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/ _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
participants (3)
-
Brandon Simmons -
Carter Schonwald -
Erik de Castro Lopo