Are you sure? I use ghc 7.6.2 (compiled with -O2) and without bang patternsfor 1million iterations it blows stack space.With bang patterns it runs in constant space , same as other version? bmaxa@maxa:~/haskell$ ./state +RTS -s500000500000 52,080 bytes allocated in the heap 3,512 bytes copied during GC 44,416 bytes maximum residency (1 sample(s)) 17,024 bytes maximum slop 1 MB total memory in use (0 MB lost due to fragmentation) Tot time (elapsed) Avg pause Max pause Gen 0 0 colls, 0 par 0.00s 0.00s 0.0000s 0.0000s Gen 1 1 colls, 0 par 0.00s 0.00s 0.0001s 0.0001s INIT time 0.00s ( 0.00s elapsed) MUT time 0.00s ( 0.00s elapsed) GC time 0.00s ( 0.00s elapsed) EXIT time 0.00s ( 0.00s elapsed) Total time 0.00s ( 0.00s elapsed) %GC time 0.0% (6.2% elapsed) Alloc rate 0 bytes per MUT second Productivity 100.0% of total user, 0.0% of total elapsed
Date: Wed, 20 Mar 2013 08:04:01 +0200 From: to.darkangel@gmail.com To: bmaxa@hotmail.com CC: haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Streaming bytes and performance
On 03/20/2013 12:47 AM, Branimir Maksimovic wrote:
Your problem is that main_6 thunks 'i' and 'a' . If you write (S6 !i !a) <- get than there is no problem any more...
Nope :( Unfortunately that doesn't change anything. Still allocating...