Hello Mathieu, Friday, April 16, 2010, 12:42:29 PM, you wrote:
Sure. But I was curious if to see whether there was some optimization I had missed, seeing as other similarly low level programs, such as the nsieve benchmark of the language shootout, or the word counting program, manage to run within a few percentage points of C if not faster.
you know it's the big game with $00000's hanging around. sometimes we rewrite programs, sometimes libs and sometimes compiler itself. the best way to optimize your program is to add it to shootout itself :))) i know one case when required function was added to the library and i know that ghc was added better code generation for short loops. probably it was enough to shootout programs but not your one. but of course if making full-fledged optimizing compiler was so easy, it was made to C and Haskell many years ago
Since this program doesn't use any features specific to functional programming, such as higher order functions, and mostly just calls out to imperative primitives of GHC not implemented in Haskell (such as unsafeRead and unsafeWrite), I would have thought that the gap in runtimes might have been smaller.
it's not runtimes, but code generation. ghc -O2 should be rather close to gcc -O0. you just undervalue amount of work done in gcc in those 20 years :) -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com