On 02/11/11 09:17, Eugene Kirpichov wrote:
Hello,
I've got two very simple programs that draw a very simple picture using cairo, doing a couple hundred thousand of cairo calls. One program is in C++. The other is in Haskell and uses the cairo library bindings.
The C++ program completes in a fraction of a second, the Haskell program takes about 7-8 seconds to run. They produce exactly the same output.
What could be at fault here? Why are the cairo bindings working so slow? (I suppose there isn't too much cairo-specific stuff here, perhaps it's a general FFI question?)
I filed a bug report about this some months ago, having noticed similar slowness: gtk2hs ticket #1228 "cairo performance is very bad" http://hackage.haskell.org/trac/gtk2hs/ticket/1228 My conclusion was that it isn't FFI being slow, but some other reason, possibly too much redirection / high level fanciness in the implementation of cairo bindings that the compiler can't see through to optimize aggressively, or possibly some Double / CDouble / realToFrac rubbishness. Claude