[Pyrex] Pyrex method 10x slower than Python, any hints why?

[David Chiang]

Hi, I'm embarrassed to say that my problem was in relying on hotshot's reporting of total CPU time -- after paring things down, I found that the Pyrex version ran twice as fast (according to resource.getrusage's user+system time) but hotshot was reporting it as twice as slow! 

 So this is no longer a Pyrex issue (apologies), and maybe it's already a well-known issue with the profiler, but, for the curious, here is an example which displays the effect in a more pronounced way. The fact that C.m() is contained in a class and that it makes many calls to m.f() both appear to be necessary for it to happen.
 
 main.py (measurement code omitted)
 ------------
 import c1, c2
  
 o1 = c1.C()
 o2 = c2.C()
  
 def f1():
     o1.m()
  
 def f2():
     o2.m()
  
 for j in xrange(2):
     t = cpu()
     for i in xrange(10000):
         f1()
     print ("python: %f s" % (cpu()-t))
   
     t = cpu()
     for i in xrange(10000):
         f2()
     print ("pyrex:  %f s" % (cpu()-t))
 
 
 c1.py = c2.pyx
  ----------------------
 import m
  
 class C:
     def m(self):
         for i in xrange(1000):
             m.f()
 
 
 m.pyx
 -----------
 def f():
     pass
 
 Output
 ----------
 python: 32.786016 s
 pyrex:  2.280653 s
 python: 32.802013 s
 pyrex:  2.275654 s
          60010 function calls in 4.625 CPU seconds
  
    Ordered by: internal time, call count
  
    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
     20000    4.521    0.000    4.521    0.000 main.py:21(f2)
     20000    0.072    0.000    0.104    0.000 main.py:18(f1)
     20000    0.033    0.000    0.033    0.000 c1.py:4(f)
         1    0.000    0.000    0.000    0.000 c1.py:1(?)
         8    0.000    0.000    0.000    0.000 main.py:5(cpu)
         1    0.000    0.000    0.000    0.000 c1.py:3(C)
         0    0.000             0.000          profile:0(profiler)
 
 
 
 David
 
 
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