On 12 Nov, 18:32, "Alf P. Steinbach" <al...@start.no> wrote:
> Hm, this seems religious. > > Of course Python is slow: if you want speed, pay for it by complexity. Not really. The speed problems of Python can to a large extent be attributed to a sub-optimal VM. Perl tends to be much faster than Python. Certain Common Lisp and Scheme implementations can often perform comparable to C++. There are JIT-compiled JavaScript which are very efficient. Java's Hotspot JIT comes from StrongTalk, a fast version of SmallTalk. It's not the static typing that makes Java run fast. It is a JIT originally developed for a dynamic language. Without Hotspot, Java can be just as bad as Python. Even more remarkable: Lua with LuaJIT performs about ~80% of GCC on Debian benchmarks. Question: Why is Lua so fast and Python so slow? Here we have two very similar dynamic scripting languages. One beats JIT-compiled Java and almost competes with C. The other is the slowest there is. Why? Lot of it has to do with the simple fact that Python' VM is stack-based whereas Lua's VM is register based. Stack-based VM's are bad for branch prediction and work against the modern CPUs. Python has reference counting which is bad for cache. Lua has a tracing GC. But these are all implementation details totally orthogonal to the languages. Python on a better VM (LuaJIT, Parrot, LLVM, several JavaScript) will easily outperform CPython by orders of magnitide. Sure, Google can brag about Go running at 80% of C speed, after introducing static typing. But LuaJIT does the same without any typing at all. -- http://mail.python.org/mailman/listinfo/python-list
